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Selected AbstractsUse and misuse of the reduced major axis for line-fittingAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Richard J. Smith Abstract Many investigators use the reduced major axis (RMA) instead of ordinary least squares (OLS) to define a line of best fit for a bivariate relationship when the variable represented on the X -axis is measured with error. OLS frequently is described as requiring the assumption that X is measured without error while RMA incorporates an assumption that there is error in X. Although an RMA fit actually involves a very specific pattern of error variance, investigators have prioritized the presence versus the absence of error rather than the pattern of error in selecting between the two methods. Another difference between RMA and OLS is that RMA is symmetric, meaning that a single line defines the bivariate relationship, regardless of which variable is X and which is Y, while OLS is asymmetric, so that the slope and resulting interpretation of the data are changed when the variables assigned to X and Y are reversed. The concept of error is reviewed and expanded from previous discussions, and it is argued that the symmetry-asymmetry issue should be the criterion by which investigators choose between RMA and OLS. This is a biological question about the relationship between variables. It is determined by the investigator, not dictated by the pattern of error in the data. If X is measured with error but OLS should be used because the biological question is asymmetric, there are several methods available for adjusting the OLS slope to reflect the bias due to error. RMA is being used in many analyses for which OLS would be more appropriate. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Postpartum dissection of the left main coronary arteryCLINICAL CARDIOLOGY, Issue 4 2006Ian S. Rogers M.D., M.B.A. Abstract Peripartum coronary artery dissection is rare, but it is an increasingly recognized risk to women of childbearing age. Literature reviews reveal that about 80% of the population with spontaneous coronary artery dissections (SCAD) are female, and approximately 25,33% of cases occurred while the woman was pregnant or in the peripartum phase. Most cases have presented within 2 weeks of delivery. The left anterior descending is the most commonly affected vessel. The etiology is poorly understood, but many reports suggest that SCAD occurs as a result of protease release secondary to an eosinophilic vasculitis resulting in vessel lysis. Many investigators have examined the correlation between peripartum SCAD and estrogen levels; however, case studies have shown conflicting results regarding estrogen levels as the putative causative factor. Optimal treatment remains controversial. Presently, stenting appears to be best employed in the patients who have single-vessel dissection not involving the left main coronary artery (LMCA). Surgical revascularization via coronary artery bypass graft remains the optimal therapy in patients whose dissection involves the LMCA, in patients with concurrent multi-vessel dissection, and in patients with disease refractory to medical management. It is important to consider coronary artery dissection in the differential of any young woman who presents with signs or symptoms consistent with acute coronary syndrome, particularly if she is peripartum. Furthermore, once suspected, it is imperative that a definitive diagnostic study, that is, coronary angiography, be completed prior to the initiation of treatment whenever possible. [source] EARLY DIAGNOSIS OF SMALL PANCREATIC CANCER: ROLE OF ENDOSCOPIC ULTRASONOGRAPHYDIGESTIVE ENDOSCOPY, Issue 2009Atsushi Irisawa Advanced pancreatic cancer is a major cause of cancer-related death. However, if surgery achieves clear margins and negative lymph nodes, the prognosis for survival can be prolonged. Therefore, early diagnosis , as early as possible , is important for improving overall survival and quality of life in patients with pancreatic cancer. Because of higher imaging resolution near the pancreas through the gastroduodenal wall, endoscopic ultrasonography enables detection of subtle pancreatic abnormalities. In fact, many investigators have reported the high ability of EUS not only for detection of small lesions but also recognition of chronic pancreatitis, which is the risky status of pancreatic cancer. As a tool for early diagnosis of pancreatic cancer, EUS is a highly anticipated modality. [source] Direct removal in the mouse of a floxed neo gene from a three-loxp conditional knockout allele by two novel approaches,GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 1 2001Xiaoling Xu Abstract Summary: The presence in an intron of the ploxP-neo-loxP cassette often results in severe interference with gene expression. Consequently, many investigators selectively remove the ploxP-neo-loxP cassette by transient expression of Cre in ES cells. Although effective, the added manipulation of the ES cells may reduce the likelihood that a clone will be able to transmit via the germline. Therefore, we developed two novel approaches that remove the ploxP-neo-loxP by Cre-mediated recombination in mouse. First, the ploxP-neo-loxP-containing mice were crossed with EIIa-Cre transgenic mice. Second, a Cre-expression plasmid was injected into pronuclei of fertilized eggs bearing the ploxP-neo-loxP allele. Both approaches produced mosaic mice with partial and complete excision. These mosaic mice were then mated, and the neo-less conditional knockout allele was found in the offspring after screening only a few litters. These procedures provide options for removing neo directly in the mouse in addition to the commonly used approach that deletes neo in ES cells. genesis 30:1,6, 2001. © 2001 Wiley-Liss, Inc. [source] Characteristics of skin aging in Korean men and womenINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2005J. H. Chung Introduction Korea is located between Japan and Mainland China. The people of these three countries have similar appearances and it is difficult to differentiate between them. Although the population of Asia is more than half of the total population of the Earth, the inherent characteristics of Asian skin have not been well investigated. Commercial markets for cosmetics and drugs for photoaged skin are rapidly expanding in many Asian countries. Therefore, many investigators in the field of dermatology and cosmetology have become interested in brown Asian skin. Clinical characteristics of skin aging and photoaging in Asians Skin aging can be divided into two basic processes: intrinsic aging and photoaging [1]. Intrinsic aging is characterized by smooth, dry, pale, and finely wrinkled skin, whereas photoaging, which indicates premature skin aging in chronically photodamaged skin, is characterized by severe wrinkling and irregular pigmentation. The pattern of wrinkling in Asians seems to differ from that in Caucasians. Asians have coarser, thicker and deep wrinkles, particularly in the forehead, perioral and Crow's foot areas. In contrast, Caucasians usually have relatively fine cheek and Crow's foot wrinkles. The reasons for these differences are not known and need further investigation. There are racial, ethnic and genetic differences, and differences of skin structure and function, between the brown skin of Asians and the white skin of Caucasians. As Asian skin is more pigmented, acute and chronic cutaneous responses to UV irradiation differ from those in white skin. Many people believe, based on clinical impressions, that the main process of photoaging in Asians involves pigmentary changes, rather than wrinkling. However, no study has been performed to confirm this belief. Risk factors for skin wrinkles and their relative risks in Korean skin [2] Various factors such as age, sun-exposure, and smoking are known to be important risk factors for wrinkles. However, the relative risks of each factor on wrinkles in the brown skin of Asians have not been investigated, and they could differ from those in Caucasians. An evaluation system for skin wrinkling is necessary for Asian skin [3]. Thus, we developed an eight-point photographic scale for assessing wrinkles in both Korean genders [2]. This scale can probably be applied to the populations of other Asian countries, at least to the Japanese and Chinese. The pattern of wrinkles in both genders appears to be similar. Age Age is an important risk factor for wrinkling in Asians, as in Caucasians. Korean subjects in their 60s showed a 12-fold increased risk of wrinkling, while subjects in their 70s have a 56-fold increased risk compared with young age group. UV light It is well known that the UV component in sunlight can cause and accelerate photoaging. The pigmented skin of Asian may better protect skin from acute and chronic UV damage. However, we found a strong association between sun-exposure and the development of wrinkling in Koreans. It was found that sun exposure of more than 5 h per day was associated with a 4.8-fold increased risk in wrinkling versus less than 2 h of sun-exposure in Koreans. Estrogen deficiency Korean females have more wrinkles than men, after controlling for age, sun exposure, and smoking, it was found that they have a 3.6-fold increased risk of developing wrinkles than their male counterparts [2]. It has also been reported, that the relative risk for wrinkling in women is higher than in men as for in white Caucasians [4]. The reason why women show more wrinkles remains to be determined. It is possible that a reduction in skin collagen because of estrogen deficiency in postmenopausal woman may aggravate wrinkling severity. Korean women with more than 10 years since menopause showed a 3.9-fold higher risk of wrinkling than the women 5 years of beyond menopause [5]. We demonstrated that women with a history of HRT have a significantly lower risk, more specifically, one fifth of the risk of facial wrinkling relative to those who had no history of HRT. Interestingly, we found that wrinkle severity significantly increased with an increasing number of full term pregnancies. The relative risk for severe wrinkling is increased by approximately 1.8-fold per full term pregnancy. Smoking It is known that smoking causes skin wrinkling in Caucasians, and that it plays no role in Blacks [6, 7]. Koreans with have a smoking history of more than 30 pack years showed a more than 2.8-fold increased risk of wrinkles [2]. The relative risks of wrinkles associated with a 30,50 pack-years history of smoking were 2.8- and 5.5-fold, respectively. Dyspigmentation in Asian skin To follow pigmentary changes, six photographic standards for both genders were developed for Korean skin, to produce a 6-point scale [2, 8]. Hyperpigmented spots, mostly lentigines, were prominent among women, while seborrheic keratosis tended to be more prominent in men. Seborrheic keratosis in Korean men Seborrheic keratoses (SKs) are benign cutaneous tumors. They have diverse clinical and histopathological appearances and are very common in the elderly (over 50 years old). The etiology of SKs is not well understood, although patients with a great number of lesionsshow a familial trait with an autosomal dominant pattern, and human papilloma virus has been suggested as possible cause because of verrucous appearance of the lesions. Exposure to sunlight has been suggested to be a risk factor for SKs. However, there is still some debate in terms of the role of sunlight. Recently, we have investigated the clinical characteristics of SKs and relationship between SKs and sunlight exposure in Korean males [9]. The prevalence of SKs in Koreans increases with age; it rose from 78.9% at 40 years, to 93.9% at 50 years and 98.7% in those over 60 years. Exposed areas, i.e. the face, neck and dorsum of the hands, demonstrate a significant increase in the prevalence of SKs by decade, whereas partly exposed areas, although SKs tended to increase in prevalence with age, this trend was not significant. When the estimated body surface area (BSA) is taken into account, the number of SKs on both the face and dorsum of the hands (0.51 ± 0.08 per 1% BSA) was over-represented compared with the trunk. SKs were also concentrated on the neck (0.38 ± 0.07 per 1% BSA) and in the V-area (0.47 ± 0.09 per 1% BSA). Outer forearms also showed 3-fold more SKs per unit area than neighboring arms and inner forearms, which are classified as partly exposed area (0.09 ± 0.02, 0.03 ± 0.01, respectively). The total area covered by SKs on exposed area also became significantly larger with aging than on intermittently exposed areas. These results indicate that exposure to sunlight might be related to SK growth. Our results indicated that excessive sun exposure is an independent risk factor of SKs. After controlling for age, smoking, and skin type, subjects with a sun exposure history of more than 6 hours per day showed a 2.28-fold increased risk of having severe SKs (n , 6) compared with those exposed for less that 3 h per day. These findings indicated that sun-exposure may play an important role in SK development. In summary, SKs are very common in Korean males and represent one of the major pigmentary problems. SKs concentrate on exposed skin, especially on the face and dorsum of the hands. Both age and lifetime cumulative sunlight exposure are important contributing factors and may work in a synergistic manner. Conclusion Many people tend to believe that wrinkles are not a prominent feature of Asian photoaged skin, and that dyspigmentation is a major manifestation in Asian skin. Contrary to this impression, wrinkling is also a major problem in the photoaged skin of Asians, and Korean people showing severe pigmentary changes usually tend to have severe wrinkles. In conclusion, the wrinkling patterns and pigmentary changes of photoaged skin in East Asians differ from those of Caucasians, and the relative risks of aggravating factors may be different from those of Caucasian skin. References 1.,Gilchrest, B.A. Skin aging and photoaging: an overview. J. Am. Acad. Dermatol. 21, 610,613 (1989). 2.,Chung, J.H. et al. Cutaneous photodamage in Koreans: influence of sex, sun exposure, smoking, and skin color. Arch. Dermatol. 137, 1043,1051 (2001). 3.,Griffiths, C.E. et al. A photonumeric scale for the assessment of cutaneous photodamage. Arch. Dermatol. 128, 347,351 (1992). 4.,Ernster, V.L. et al. Facial wrinkling in men and women, by smoking status. Am. J. Public Health. 85, 78,82 (1995). 5.,Youn, C.S. et al. Effect of pregnancy and menopause on facial wrinkling in women. Acta Derm. Venereol. 83, 419,424 (2003). 6.,Kadunce, D.P. et al. Cigarette smoking: risk factor for premature facial wrinkling. Ann. Intern. Med. 114, 840,844 (1991). 7.,Allen, H.B., Johnson, B.L. and Diamond, S.M. Smoker's wrinkles? JAMA. 225, 1067,1069 (1973). 8.,Chung, J.H. Photoaging in Asians. Photodermatol. Photoimmunol. Photomed. 19, 109,121 (2003). 9.,Kwon, O.S. et al. Seborrheic keratosis in the Korean males: causative role of sunlight. Photodermatol. Photoimmunol. Photomed. 19, 73,80 (2003). [source] Nuclear matrix proteins as biomarkers in prostate cancerJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2002Eddy S. Leman Abstract The nuclear matrix (NM) is the structural framework of the nucleus that consists of the peripheral lamins and pore complexes, an internal ribonucleic protein network, and residual nucleoli. The NM contains proteins that contribute to the preservation of nuclear shape and its organization. These protein components better known as the NM proteins have been demonstrated to be tissue specific, and are altered in many cancers, including prostate cancer. Alterations in nuclear morphology are hallmarks of cancer and are believed to be associated with changes in NM protein composition. Prostate cancer is the most frequently diagnosed cancer in American men and many investigators have identified unique NM proteins that appear to be specific for this disease. These NM protein changes are associated with the development of prostate cancer, as well as in some cases being indicative of cancer stage. Identification of these NM proteins specific for prostate cancer provides an insight to understanding the molecular changes associated with this disease. This article reviews the role of NM proteins as tumor biomarkers in prostate cancer and the potential application of these proteins as therapeutic targets in the treatment of this disease. J. Cell. Biochem. 86: 213,223, 2002. © 2002 Wiley-Liss, Inc. [source] Sympathovagal effects of spinal anaesthesia with intrathecal or intravenous fentanyl assessed by heart rate variabilityACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009Y. FUJIWARA Background: Although many investigators previously reported the sympathovagal effect of spinal anaesthesia, there is no information about the sympathovagal effects of supplementation with fentanyl. The aim of this study was to evaluate the sympathovagal effects of intrathecal or intravenous fentanyl added to spinal anaesthesia. Methods: One hundred and twenty patients undergoing elective transurethral surgery under spinal anaesthesia were randomly allocated to receive intrathecally either isobaric bupivacaine alone (Group B), bupivacaine supplemented with intrathecal (Group Ft) or with intravenous fentanyl (Group Fv). Heart rate variability was estimated using the MemCalc method (Tarawa, Suwa Trust, Japan) before and after spinal anaesthesia. Results: In all groups, spinal anaesthesia significantly decreased low frequency/high frequency (LF/HF) as a marker of sympathovagal balance. However, patients in Group B with a low block height developed a marked increase in LF/HF after spinal anaesthesia, which was attenuated in Group Ft. Meanwhile, intravenous fentanyl did not attenuate this response. Conclusion: We conclude that sympathetic activation observed in patients with a low block height was attenuated by intrathecal fentanyl but not by intravenous fentanyl. [source] Review article: hepatitis C virus infection and type-2 diabetes mellitus in renal diseases and transplantationALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2005F. Fabrizi Summary A link between hepatitis C virus infection and development of diabetes mellitus has been suggested by many investigators; however, this remains controversial. The mechanisms underlying the association between hepatitis C virus and diabetes mellitus are unclear but a great majority of clinical surveys have found a significant and independent relationship between hepatitis C virus and diabetes mellitus after renal transplantation and orthotopic liver transplantation. We have systematically reviewed the scientific literature to explore the association between hepatitis C virus and diabetes mellitus in end-stage renal disease; in addition, data on patients undergoing orthotopic liver transplantation were also analysed. The unadjusted odds ratio for developing post-transplant diabetes mellitus in hepatitis C virus-infected renal transplant recipients ranged between 1.58 and 16.5 across the published studies. The rate of anti-hepatitis C virus antibody in serum was higher among dialysis patients having diabetes mellitus (odds ratio 9.9; 95% confidence interval 2.663,32.924). Patients with type-2 diabetes-related glomerulonephritis had the highest anti-hepatitis C virus prevalence [19.5% (24/123) vs. 3.2% (73/2247); P < 0.001] in a large cohort of Japanese patients who underwent renal biopsy. The link between hepatitis C virus and diabetes mellitus may explain, in part, the detrimental role of hepatitis C virus on patient and graft survival after orthotopic liver transplantation and/or renal transplantation. Preliminary evidence suggests that anti-viral therapies prior to renal transplantation and novel immunosuppressive regimens may lower the occurrence of diabetes mellitus in hepatitis C virus-infected patients after renal transplantation. Clinical trials are under way to assess if the hepatitis C virus-linked predisposition to new onset diabetes mellitus after renal transplantation may be reduced by newer immunosuppressive medications. [source] Experimental Models To Investigate Inflammatory Processes in Chronic Venous InsufficiencyMICROCIRCULATION, Issue S1 2000RONALD J. KORTHUIS ABSTRACT Chronic venous insufficiency (CVI) is characterized by leukocyte adhesion and infiltration, venous hypertension and dilatation, and valvular dysfunction. The fact that activated white cells can direct a powerful cytotoxic arsenal at parenchymal cells following their extravasation into the tissues led to the original proposal that leukocytes may play a causative role in the pathogenesis of venous disease. A large body of subsequent work indicates that white blood cells are indeed activated in CVI. However, identification of the factors responsible for initiating leukosequestration and activation in such disorders and determination of whether these activated cells then contribute to the progression of venous disease have been hampered by the lack of appropriate animal models that accurately mimic the human condition. Tantalizing evidence suggesting that cyclical periods of ischemia and reperfusion (I/R) may occur in diseased regions of the skin is beginning to accumulate. As is the case with CVI, leukocyte infiltration is a prominent feature in I/R and activated neutrophils play a causative role in the reperfusion component of tissue injury via the targeted release of reactive oxygen metabolites and hydrolytic enzymes. In light of these considerations, many investigators have suggested that examining the mechanisms of I/R injury in skin and skeletal muscle, where ischemia is produced by arterial occlusion, may provide a relevant model for studying the pathogenesis of CVI. Others have suggested that venous occlusion may represent a more appropriate model, as this approach also produces the venous hypertension that is characteristic of the disease. The purpose of this review is to summarize the evidence pointing to the involvement of I/R and venous hypertension as causative factors in CVI-induced leukocyte recruitment. In addition, we will describe the evidence in favor of the view that white blood cells contribute to the pathogenesis of CVI. Finally, we will describe several different experimental models that have been used to examine the role of I/R-induced microvascular dysfunction as it may pertain to the development of CVI, together with a discussion of the relative advantages and limitations of the various models. [source] Expression of wild-type estrogen receptor , protein in human breast cancer: Specific correlation with HER2/neu overexpressionPATHOLOGY INTERNATIONAL, Issue 8 2006Yoshihisa Umekita Expression of estrogen receptor , (ER,) protein in human breast cancer and correlation with clinicopathological factors have been reported by many investigators, but many of them used ER, antibodies that react with both wild-type ER, (ER,wt) and splicing variant isoform. Therefore, the frequency and correlation with clinicopathological factors of ER,wt expression remain to be established. In the present study a monoclonal antibody EMR02, specific for ER,wt, was used in formalin-fixed paraffin-embedded sections from 225 female primary breast cancer patients diagnosed as having invasive ductal carcinoma. Expression of ER,, progesterone receptor (PgR) and HER2/neu were also investigated by immunohistochemistry. For ER,wt, ER, and PgR, positivity was defined as nuclear staining in >10% of the cancer cells. HER2/neu overexpression was defined as a Hercep test score 3+. Positivity for ER,wt, ER,, PgR and HER2/neu overexpression was 55%, 74%, 61% and 25%, respectively. The expression of ER,wt had a positive correlation with ER, (P = 0.018) and PgR (P = 0.02). There was significant positive correlation between ER,wt expression and HER2/neu overexpression (P < 0.0001). According to multivariate logistic regression analysis the most significant association was between ER,wt expression and HER2/neu overexpression (P < 0.0001). These results suggest that clinical significances of ER,wt expression in human breast cancer patients may be more complex. [source] Seasonal and spatial patterns of population density in the marine macroalga Mazzaella splendens (Gigartinales, Rhodophyta)PHYCOLOGICAL RESEARCH, Issue 1 2006Leonard James Dyck SUMMARY Insight into demographic processes that operate at larger spatial scales can be achieved through studying local populations when a particular species of interest is examined over time, by many investigators, in a variety of locations. On the west coast of North America, Mazzaella splendens (Setchell et Gardner) Fredericq is such a species of interest. A synthesis of local demographic studies of M. splendens from the late 1960s to the present reveals a pattern that is potentially common to the larger natural populations. This is the pattern: population density is high in summer and low in winter for both alternate free-living life history phases of M. splendens. The magnitude of this seasonal change decreases in increasingly wave-exposed habitats. In wave-sheltered habitats there is a seasonal alternation from summer haploid to winter diploid dominance. This alternation gradually changes to constant diploid dominance as wave exposure in the habitat increases. Changes in population density are primarily a function of appearances and disappearances of perennating basal crusts (genets), as modules are produced or lost, rather than differential module production by genets of one phase over those of the other. To test the generality of this pattern, we examined seasonal changes in density, in local populations of M. splendens, in both a wave-sheltered and a wave-exposed habitat at Second Beach, Barkley Sound. Greater seasonal fluctuation in population density at wave-sheltered, compared to wave-exposed habitats is supported as a pattern potentially common to the natural populations of M. splendens. A change from summer haploid dominance in wave-sheltered areas to summer diploid dominance in wave-exposed areas is similarly supported. All changes in population density were the result of appearances and disappearances of genets rather than differential module production by haploid versus diploid basal crusts, also consistent with previous observations. A seasonal alternation in phase dominance, however, was absent from the wave-sheltered site at Second Beach, Barkley Sound for 3 consecutive years. Seasonal alternation in phase dominance of M. splendens appears dependent on local conditions and is not common to all natural populations. [source] A critique of the grandmother hypotheses: Old and newAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2001Jocelyn Scott Peccei The singularity of reproductive senescence in human females has led many investigators to consider menopause an adaptation permitting increased maternal investment in existing progeny. Much of the focus has been on the grandmother hypothesis,the notion that aging women gain an inclusive fitness advantage from investing in their grandchildren. This hypothesis has evolved from an explanation for menopause into an explanation for the exceptionally long postreproductive lifespan in human females. In the old grandmother hypothesis, menopause is an adaptation facilitating grandmothering; it is about stopping early in order to create a postreproductive lifespan. In the new grandmother hypothesis, grandmothering is an adaptation facilitating increased longevity, and menopause is a byproduct. This paper reviews and critically evaluates the evidence for and against both hypotheses, focusing on key predictions of each. If menopause is the result of selection for increased maternal investment, this involved mainly mothers, not grandmothers. Am. J. Hum. Biol. 13:434,452, 2001. © 2001 Wiley-Liss, Inc. [source] Intervertebral disc degeneration: New insights based on "skipped" level disc pathologyARTHRITIS & RHEUMATISM, Issue 8 2010Kenneth M. C. Cheung Objective Typically, age and abnormal physical loading ("wear and tear") have been associated with the development of intervertebral disc degeneration. In the past decade, various additional etiologic factors for disc degeneration have been sporadically reported in the literature; however, many investigators continue to place tremendous emphasis on the effects of age and biomechanics associated with disc degeneration. The aim of this study was to provide additional insight into the notion that age and biomechanics are key factors in the development of disc degeneration. To this end, we addressed the prevalence of and risk factors associated with a unique pattern of disc degeneration of the lumbar spine, "skipped" level (nonconsecutive) disc degeneration (SLDD). Methods As part of a large genetics-based study in southern Chinese individuals (n = 1,989), a cross-sectional analysis was performed in subjects exhibiting disc degeneration in ,2 levels (n = 838) who were then categorized as having SLDD (n = 174) or non-SLDD (contiguous, multilevel; n = 664). Various radiographic parameters were assessed based on T2-weighted magnetic resonance imaging (MRI). Subject demographics were assessed, and univariate and multivariate logistic regression analyses were performed. Results Overall, 8.7% of the whole population (n = 1,989) had SLDD, while it was present in 20.8% of subjects with multilevel disc degeneration (n = 838). SLDD was more prevalent in male subjects (adjusted odds ratio [OR] 1.48, 95% confidence interval [95% CI] 1.04,2.10, P = 0.028). SLDD was significantly associated with the presence of Schmorl's nodes (adjusted OR 2.72, 95% CI 1.78,4.15, P < 0.001), which also presented in levels with no disc degeneration. A history of disc bulge/extrusion (P = 0.004) and/or a history of back injury (P = 0.010) was significantly associated with non-SLDD, and a greater degree of overall severity of disc degeneration was also associated with non-SLDD. Other demographic and MRI findings did not significantly differ between groups. Conclusion To our knowledge, this report is the first to describe the prevalence and risk factors associated with SLDD. Our study challenges the paradigm that age and biomechanics are the key factors associated with the development of disc degeneration. Although age and biomechanical factors may play a role in the manifestation of disc degeneration, our novel findings of SLDD patterns provide further awareness of and support for the notion that additional etiologic factors may play a role in the development of disc degeneration. Such factors warrant further investigation to shed light on the cause of disc degeneration. [source] Hypothesis: Could Epstein-Barr virus play a role in the development of gastroschisis?BIRTH DEFECTS RESEARCH, Issue 2 2010Martha M. Werler BACKGROUND: The strong inverse association between maternal age and risk of gastroschisis in offspring has spurred many investigators to hypothesize that behaviors among younger females are the cause. Examples include cigarette smoking, illicit drugs, genitourinary infections, and sexually transmitted diseases, each of which has been reported to be associated with gastroschisis. Although these exposures are more common in young women, recent studies have shown that cigarette smoking, genitourinary infections, and sexually transmitted diseases are most strongly associated with gastroschisis in older women. There is both anecdotal and published evidence showing that gastroschisis sometimes (but not always) occurs in clusters, raising the possibility that an infectious agent might be involved in its pathogenesis. RESULTS: One such agent whose epidemiologic characteristics parallel those of gastroschisis is Epstein-Barr virus (EBV). Primary EBV infection in early childhood has been decreasing over time, leaving a greater proportion of adolescents at risk, as reflected by increased rates of infectious mononucleosis over time. During the childbearing years, risk of primary EBV infection decreases dramatically, as does risk of gastroschisis. The stronger risks of gastroschisis associated with cigarette smoking, genitourinary infections, and sexually transmitted diseases in older women might be explained by EBV reactivation resulting from multiple challenges to immune response such as pregnancy, age, toxic exposures, and genitourinary and sexually transmitted infections. CONCLUSION: EBV and other herpes viruses should be added to the research agenda for gastroschisis. Birth Defects Research (Part A) 2010. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||