Determinants of serum 25-hydroxyvitamin d levels in healthy young adults living in the Western Cape, South Africa

Background: Vitamin D deficiency is fast emerging as a global pandemic. In South Africa few studies have been conducted to determine the vitamin D status of the healthy population.Methods: This prospective study with an analytical component investigated vitamin D status of healthy undergraduate students at two time points (winter and summer) at Stellenbosch University. Serum 25(OH)D was determined, anthropometric measurements taken and dietary vitamin D intake estimated (food-frequency questionnaire). Skin tone was determined (Fitzpatrick skin type classification), and a skin reflectometry device used to measure dermal melanin content.Results: Results of 242 students indicated a mean serum 25(OH)D of 63.80 ± 41.35 ng/ml and a high prevalence of vitamin D sufficiency (88%). Significantly more females experienced suboptimal vitamin D levels than males (18 vs. 5%; p < 0.01). Participants with lighter skin tones had higher levels of 25(OH)D than those with darker skin tones (chi-square = 24.02; p = 0.02). The majority (60.74%) had a normal BMI, although there was no significant relationship between BMI and serum 25 (OH)D (Spearman's r=­0.11; p = 0.09). Total mean dietary vitamin D intake was 7.99 ± 13.81 mcg, with 87.2% having inadequate intake (< 15 mcg). The relationship between total vitamin D intake and serum 25(OH)D was found to be significant in winter (p < 0.001) and summer (p = 0.01). Serum vitamin D levels were significantly higher in the winter phase (p < 0.001).Conclusions: A low prevalence of vitamin D deficiency was found amongst healthy young adults, despite low dietary vitamin D intakes. Significant relationships were found between serum 25(OH)D and gender, skin tone and vitamin D intake. Further studies need to be conducted, especially in high-risk groups, before results are applied to the greater South African public

Report from the national transplantation pregnancy registry (NTPR): outcomes of pregnancy after transplantation.

The NTPR continues to analyze the safety of pregnancy in female transplant recipients as well as outcomes of pregnancies fathered by male transplant recipients. With regard to female recipients, pregnancy does not appear to adversely affect graft function, when the function of the transplanted graft is stable prior to pregnancy. A small percentage of recipients with each transplanted organ develops rejection, graft dysfunction or graft loss. These events may occur in recipients with pre-pregnancy graft dysfunction or on occasion, occur unpredictably. Female cyclosporine-treated kidney recipients with both shorter and longer intervals from transplant to conception have been analyzed, with favorable outcomes noted. It appears sensible to continue to advise recipients to wait one to 2 years after transplant to allow for stable graft function as well as stabilization of immunosuppressive medications. However, given that favorable outcomes can occur with either shorter or longer intervals, these recipients need to be counseled and followed on a case-by-case basis. Newer agents and more potent regimens are under continued surveillance. Two cases with structural malformations have been noted in female recipient offspring with exposure to MMF during pregnancy. Data remain limited and are insufficient to determine a specific malformation incidence. The risk of graft rejection as well as graft dysfunction must be weighed against the risk of potential teratogenicity when maintaining female recipients on MMF during pregnancy. For male recipients maintained on MMF, there have been no patterns of problems noted in their offspring. The structural malformation incidence in newborn of cyclosporine-treated recipients is in the range expected for the general population without any specific predominance of malformations. It remains to be seen whether or not any specific pattern of problems will become apparent in the newborn with newer regimens. Controversy surrounding breastfeeding continues, although it has become an option that some recipients choose to consider. Data have accrued in liver, heart, pancreas-kidney and lung recipients. Among lung recipients, there appears to be poorer maternal survival postpartum, which may be related to pregnancy or may be inherent in this population. Continued entries to the registry, especially in light of newer combinations of immunosuppressive agents, should help to provide the guidelines for management. All centers are encouraged to participate.

Report from the National Transplantation Pregnancy Registry (NTPR): outcomes of pregnancy after transplantation.

Safety of pregnancy in the female transplant recipient population must include consideration of 3 outcomes--mother, baby and transplanted graft. In the majority of female recipients studied, pregnancy does not appear to cause excessive or irreversible problems with graft function, if the function of the transplant organ is stable prior to pregnancy. However, a small percentage of recipients identified within each organ system may develop rejection, graft dysfunction and/or graft loss that may be related to the pregnancy and may occur unpredictably. Outcomes are not entirely similar among all organ systems, and one must consider risks on an individual organ basis. It appears reasonable to advise female recipients to wait one or 2 years after transplantation before attempting pregnancy to insure that function of the transplanted organ is adequate and stable and also to allow for stabilization of immunosuppressive medications. Favorable outcomes, however, have occurred when recipients have become pregnant less than one year from transplant, so cases must be analyzed individually. Immunosuppressive medications may have to be adjusted during pregnancy, and in some cases, rejections occur requiring additional immunosuppressive regimens (steroids and in several cases OKT3). Whether increasing immunosuppressive doses during pregnancy to adjust for falling levels lessens the rejection risk has never been studied prospectively. There is concern based on animal reproductive studies that the risk of birth defects and/or spontaneous miscarriage is increased in women exposed to MMF during pregnancy. Of the 9 pregnancies reported to the registry to date, there have been no birth defects noted among 5 liveborn of female recipients exposed to MMF. Data remain limited. For female recipients, a high incidence of low birth-weight and prematurity compared to the general population has been a consistent outcome, however, there has been no specific pattern of malformation in their newborn or any apparent increase in the incidence of small-for-gestational-age newborn. Long-term follow-up of children to date by the NTPR has been encouraging. A recent report in the literature has suggested impairment of immune function in newborn of CsA-treated mothers. Further study is needed. Some mothers have chosen to breastfeed. The potential risk to the newborn of ingested immunosuppressives compared with the potential benefits of breastfeeding is unknown and options must be discussed with the recipient. From earlier registry reports, recipients with deteriorating graft function, such as liver recipients with recurrent hepatitis C and/or other recipients with deteriorating graft function, appear to be at risk for worsened graft function with pregnancy. Outcomes of male recipient fathered pregnancies have been favorable and appear to be similar to the general population, but this group has not been as well studied as female recipients. No structural problems have been noted in the 38 offspring of males on MMF at the time of conception. Within each organ group, some female recipients have reported more than one pregnancy, sometimes on differing immunosuppressive regimens. If there is stable graft function, additional successful pregnancies are possible. Continued entries to the registry, especially in light of newer immunosuppressives and combinations of agents, are needed to continue to provide guidelines for management. The NTPR acknowledges the cooperation of transplant recipients and over 200 centers nationwide who have contributed their time and information to the registry. The NTPR is supported by grants from Novartis Pharmaceuticals Corp., Fujisawa Healthcare, Inc., Roche Laboratories Inc. and Wyeth-Ayerst Pharmaceuticals, Inc.

Comparison of students classified as LD who petitioned for or fulfilled the college foreign language requirement.

In this study, we compared the cognitive, academic achievement, and demographic profiles of 46 students from one university who had been classified as learning disabled (LD) and had received permission to substitute courses for the university's foreign language (FL) requirement (petition group) with the profiles of 21 students from the same university who had been classified as LD and had fulfilled the university's FL requirement by passing FL courses (nonpetition group). Results showed no significant differences between the two groups on measures of reading, mathematics, written language, American College Testing score, and graduating grade point average when IQ was used as a covariate. More petition than nonpetition students had at least a 1.0 SD discrepancy between IQ and achievement and had been referred only for FL learning problems. More nonpetition than petition students had taken an FL in college and received accommodations in the FL. The two groups together appeared to constitute a heterogeneous group of learners, with more than half failing to meet a minimum discrepancy criterion for classification as LD. The discussion addresses the classification system for LD, the process for determining the presence of FL learning problems and how to address them, and directions for further research.

Students classified as LD and the college foreign language requirement: a quantitative analysis.

This study was conducted to determine whether students classified as learning disabled (LD) who were permitted to substitute courses for the college foreign language (FL) requirement at one university would display significant cognitive and academic achievement differences when grouped by level of discrepancy between IQ and achievement, by discrepancy between achievement according to different measures, and by level of performance on phonological-orthographic processing measures, on the Modern Language Aptitude Test (MLAT), and in FL courses. Results showed that there were no differences among students with different levels of discrepancy (i.e., < 1.0 SD, 1.0-1.49 SD, and > 1.50 SD) on MLAT and American College Testing (ACT) scores, graduating grade point average (GPA) or college FL GPA. Results also showed that among students who scored below versus at or above the 25th percentile on phonological-orthographic processing measures, there were no differences on measures of IQ, ACT, MLAT, and GPA, as well as most measures of academic achievement. Implications for the use of the LD label to grant FL course substitutions or waivers, use of the MLAT in the diagnostic and course substitution/waiver process, and the validity and reliability of traditional criteria for the classification as LD are discussed.

Job satisfaction of college graduates with learning disabilities.

Job satisfaction, as assessed via five scales that posed questions concerning colleagues, work, supervision, pay, and promotion, as well as overall total job satisfaction, was examined for 55 self-identified college graduates with learning disabilities (LD) and 55 control graduates matched by gender, major, degree, and graduation year. All participants graduated from a competitive midwestern university from 1987 to 1994 and represented advantaged groups when compared to both LD and non-LD populations. The graduates with LD required significantly more time to complete their degrees and showed significantly lower CPAs. Data analysis indicated that the graduates with LD perceived themselves as receiving significantly less pay and promotion opportunities, and reported less total job satisfaction, than graduates without LD. However, no significant salary differences between the groups were found. The implications of these findings are examined.

Gas chromatography-mass spectrometry analysis of vitamin E and its oxidation products.

To facilitate studies of vitamin E ( alpha-tocopherol) antioxidant actions in tissues, we have developed a stable isotope dilution capillary gas chromatography-mass spectrometry assay for alpha-tocopherol and its three principal oxidation products, alpha-tocopherolquinone, 5,6-epoxy-alpha-tocopherolquinone, 2, 3-epoxy-alpha-tocopherolquinone, and for alpha-tocopherolhydroquinone, a reduction product of alpha-tocopherolquinone. Deuterium-labeled internal standards (5, 7-[2H3-methyl]-alpha-tocopherol, 2,6-[2H3-methyl]- alpha-tocopherolquinone, 2,6-[2H3-methyl]-5,6-epoxy- alpha-tocopherolquinone, 2,6-[2H3-methyl]-2,3-epoxy- alpha-tocopherolquinone, and 2-[2H3-methyl]- alpha-tocopherolhydroquinone are added to cell or tissue homogenates. The products then are extracted and converted to O-trimethylsilyl derivatives. Products are analyzed by capillary gas chromatography with on-column injection and detected by selected ion monitoring of characteristic fragment ions in electron ionization mode. Standard curves were linear from 25 fmol to 2 pmol for products and from 25 fmol to 4 pmol for alpha-tocopherol. The use of 2H6- and 2H3-internal standards for alpha-tocopherolquinone and alpha-tocopherolhydroquinone permits simultaneous analysis of both products despite possible redox interconversion during sample workup. alpha-Tocopherol oxidized in microsomes treated with azo-bis(amidinopropane HCl) was quantitatively accounted for as the epoxyquinones, alpha-tocopherolquinone, and alpha-tocopherolhydroquinone. However, over half of the oxidation products were present in microsomes as acid-labile tocopherone precursors. This method permits comprehensive assessment of vitamin E status in tissues and quantitative studies of vitamin E antioxidant actions and turnover.

Bilateral optic neuritis with branch retinal artery occlusion associated with vaccination.

A case of a 40-year old marine with bilateral optic neuritis and a branch retinal artery occlusion after vaccination is presented. Blood investigations showed no abnormalities. Cerebrospinal fluid studies revealed a lymphocytic pleocytosis and IgG antibodies against hepatitis A and rabies. Computerized tomography and magnetic resonance imaging of the brain were negative. A diagnosis of vaccine-induced auto-immune demyelinative optic neuritis was made. The clinical picture improved after systemic corticosteroid treatment.

Influence of the CSF bicarbonate concentration on the ventilatory response to CO2 in relation to the location of the central chemoreceptors.

In anaesthetized cats, in which the cerebrospinal fluid bicarbonate concentration was varied by a ventriculocisternal perfusion technique, the ventilatory response to CO2 during hyperoxia could be satisfactorily described by VE = S(PCSFCO2 -B). Both the slope S and the intercept B were positively and linearly related to the CSF bicarbonate concentration. Assuming that the PCSFCO2 is equal to the PCO2 in extracellular fluid, it can be shown that VE is a linear, but not a unique function of the [H+] at the site of the chemoreceptors; the slope of this relation varies with the bicarbonate concentration at that site, possibly due to chemical complex formation between HCO-3 and Ca2+ or Mg2+. Changes in the B-value were related to the location of the central chemoreceptors with the models of Pappenheimer and Berndt aand their coworkers. It was found that changes in the CSF bicarbonate concentration are reflected for 60 per cent at the site of the central chemoreceptors, and that this was independent of the cerebral perfusion. Using Berndt's model a distance between CSF and central chemoreceptors of approximately 100 micron was found; this calculated distance is relatively insensitive to relationship (logarithmic or not) between ventilation and H+ concentration and to changes in cerebral perfusion, owing to the approximate nature of the diffusion model.