Diabetes, pre-diabetes and insulin resistance screening in Native American children and youth.

OBJECTIVES: Early identification of pre-diabetes and insulin resistance (IR) provides an important window of opportunity for diabetes prevention. Little is known about the prevalence of pre-diabetes and IR in Native American (NA) youth. We designed a cross-sectional, community-based study of NA children to estimate the prevalence of diabetes, pre-diabetes and IR and their association with other diabetes risk factors. STUDY DESIGN: NA children (5-18 years) were screened with body mass index (BMI), blood pressure, oral glucose tolerance test (OGTT), lipids, insulin and highly sensitive C-reactive protein (hsCRP), and calculated homeostatic model assessment of IR (HOMA-IR). RESULTS: Mean age of the cohort (n=201) was 10.8 ± 3.8 years (± s.d.; 94/107 M/F). BMI percentile for age and sex (BMI%) was elevated (≥ 85 th percentile) in 58.6% of 5-11 years and 51.1% of 12-18 years, and positively correlated with HOMA-IR, blood pressure, triglycerides and hsCRP (P<0.05). The prevalence rate for pre-diabetes and diabetes were 6.5% (3.5-10.8%) and 1.0% (0.1-3.6%), respectively. Mean HOMA-IR was greater in the older than younger age group while prevalence of pre-diabetes was the same. Those with pre-diabetes and diabetes had a greater HOMA-IR, abdominal circumference and BMI% than normal youth. CONCLUSION: In the first prospective, community-based screening for pre-diabetes, IR and diabetes in United States NA youth using OGTT, while the number of diabetes cases was low, pre-diabetes was found in a significant number of youth, particularly in those with BMI ≥ 95 th%. As proportions of pre-diabetes were similar in 5-11 and 12-18 year olds, diabetes risk begins early in NA youth.

Reproductive hormones after pancreas transplantation.

BACKGROUND: Reproductive hormone function after pancreas transplantation (PTX) is unknown as it has not been studied. METHODS: We prospectively studied PTX recipients to determine changes in reproductive hormones after PTX. Testosterone or estradiol, leutinizing hormone, follicle stimulating hormone, and prolactin were determined before and 1 year after PTX in 23 patients (10 women, 13 men) followed for more than 1 year after PTX. Of these, 11 received simultaneous kidney-PTX; 8 PTX only; and 4, PTX after kidney. Average age was 38.4+/-1.6 years and average duration of diabetes was 24.5+/-1.3 years. Nine (four women, five men) patients had been on dialysis pre-PTX. Sixteen of 23 patients were treated with cyclosporine and seven with FK-506 along with prednisone and azathioprine post-PTX. RESULTS: Mean testosterone in men was normal pre- and post-PTX. Two men had secondary hypogonadism pre-PTX with resolution in one and persistence in the other post-PTX. Five of the ten women had evidence of hypogonadism pre-PTX: three had primary hypogonadism and two had secondary hypogonadism. Post-PTX, 7 of 10 women had abnormal reproductive hormones: 4 had primary hypogonadism, 2 had secondary hypogonadism, and 1 developed hyperestrogenemia with elevated estradiol (482 pg/ml) and leutinizing hormone (41 IU/liter). Mean prednisone dose and cyclosporine trough level were higher in the women than the men (P<0.05). No cases of secondary hypogonadism that developed or resolved post-PTX were related to changes in prolactin, renal function, or hyperglycemia. CONCLUSIONS: Women are more likely than men to have reproductive hormone abnormalities pre- and post-PTX and the causes may be multiple.

Possible role of endogenous retinoid (Vitamin A) toxicity in the pathophysiology of primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is a chronic, cholestatic disease of unknown etiology commonly affecting women. It is characterized by progressive destruction of the small intrahepatic bile ducts and portal inflammation, leading to fibrosis and cirrhosis. The major signs and symptoms of PBC, which include pruritus, lethargy, the sicca syndrome, and osteoporosis, closely resemble the manifestations of hypervitaminosis A. Based on a review of the literature and other observations connecting PBC with retinoid metabolism (vitamin A and its derivatives), the hypothesis is proposed that exposure to excess endogenous retinoids contributes to the pathogenesis of PBC and may be to the cause of some of the signs and symptoms associated with the disease.

Lipids increase after solitary pancreas transplantation.

OBJECTIVE: The aims of this study were to determine 1) changes in lipids after solitary pancreas transplantation (SPTX) in patients with type 1 diabetes and 2) factors that influence those changes. RESEARCH DESIGN AND METHODS: Lipids were evaluated prospectively in 24 patients who underwent SPTX. Three were excluded because of early graft failure. The remaining patients (n = 21; 13 men, 8 women) were studied for changes in lipids over time (pre-SPTX, 0-2, 3-6, 7-12, and > 12 months). Glycohemoglobin, serum creatinine, BMI, and medications were also analyzed for their effects on lipid changes. RESULTS: Cholesterol, HDL, and LDL decreased in the immediate postoperative period (0-2 months), whereas triglycerides (TGs) increased (P < 0.05). At 3-6 months, cholesterol, HDL, and TG were higher than before the SPTX, whereas LDL returned to pre-SPTX levels. After 12 months, HDL and TG remained higher than their pre-SPTX levels (P < 0.05). During the study, systolic and diastolic blood pressure increased, renal function decreased, glyco-hemoglobin improved, and weight was unchanged. Changes in cholesterol/HDL ratio, HDL, and TG correlated with changes in prednisone dose (P < 0.05), and changes in TG correlated with changes in creatinine (P < 0.05). The same pattern of lipids occurred in patients prescribed or not prescribed hypolipidemic agents. CONCLUSIONS: Lipids do not improve within the 1st year after SPTX, despite improved glycemic control and blood pressure control, and renal function is worse. These results are in contrast to those reported for combined kidney-pancreas transplantation, where lipids, blood pressure, and renal function improved immediately after transplant. Further studies are needed to determine whether lipids continue to change with time after SPTX. The impact of these changes after SPTX on overall cardiovascular risk is unknown.

Confessions of a butch straight woman.

ABSTRACT According to stereotypical homosexual images of the stone-faced woman stomping around in work boots, lesbians adopt a more masculine demeanor and style of dress after coming out. In this article the author debunks this notion by sharing her personal experience of how her appearance changed through the course of her coming out process. She contrasts her views about beauty and how she felt about her body when she lived as a straight woman to her newfound comfort and freedom as a lesbian expressing the feminine and masculine sides of herself. In an ironic twist, coming out allowed her to shed the heterosexual beauty prescriptions, reconnect with her feminine side, and come out as beautiful.

Anemia.

OBJECTIVES: To provide an overview of the disorders that cause anemia and to review clinical and laboratory assessment and medical and nursing management of the anemic patient. DATA SOURCES: Published articles and book chapters that pertain to red blood cell physiology and the major causes and types of anemia. CONCLUSIONS: Advances in molecular and genetic aspects of anemia are leading to new developments in the diagnosis and management of all types of anemia. Symptomatic relief to maintain quality of life is essential for all anemic patients. IMPLICATIONS FOR NURSING PRACTICE: Nurses can play a major role in the supportive care of patients with anemia through interventions related to pharmacological therapy, blood transfusions, nutritional counseling, and symptom management.

Peripheral intravenous myocardial contrast echocardiography using a 2% dodecafluoropentane emulsion: identification of myocardial risk area and infarct size in the canine model of ischemia.

OBJECTIVES: This study assessed the accuracy of 2% dodecafluoropentane (EchoGen), an intravenous echocardiographic contrast agent, in identifying myocardial area at risk and infarct size in the canine model of myocardial ischemia. BACKGROUND: Myocardial contrast echocardiography allows determination of myocardial area at risk and infarct size but requires intracoronary injection in humans. The development of agents that can be delivered by peripheral intravenous injection could enable bedside myocardial contrast echocardiographic assessment of risk area, infarct size and reperfusion. METHODS: Two protocols were used. Protocol 1 assessed the accuracy of myocardial contrast echocardiography using intravenous dodecafluoropentane in defining myocardial area at risk and infarct size in the canine model of regional myocardial ischemia versus gross pathologic specimens stained with monastral blue to determine area at risk and triphenyltetrazolium chloride to determine the area of necrosis. Protocol 2 assessed the effects of repeated injections of dodecafluoropentane (0.5 ml/kg body weight, four doses 30 min apart or eight doses 10 min apart) on myocardial blood flow and hemodynamic variables. RESULTS: Myocardial contrast echocardiography accurately defined area at risk and infarct size (r = 0.96 vs. triphenyltetrazolium chloride). Myocardial blood flow remained stable after multiple serial injections of dodecafluoropentane. However, a significant increase in pulmonary artery pressure and pulmonary vascular resistance, along with a decrease in arterial oxygen saturation and cardiac output, was seen in dogs that received eight injections at 10-min intervals. CONCLUSIONS: Myocardial contrast echocardiography using intravenous dodecafluoropentane accurately defined myocardial area at risk and infarct size. Hemodynamic variables and regional myocardial blood flows remained stable when dodecafluoropentane was injected at 30-min intervals for up to four doses; more frequent administration led to cardiopulmonary deterioration. Dodecafluoropentane offers the potential for reliable, noninvasive assessment of reperfusion after therapeutic interventions.

Assembly of the Photosystem II oxygen-evolving complex is inhibited in psbA site-directed mutants of Chlamydomonas reinhardtii. Aspartate 170 of the D1 polypeptide.

Photosystem II catalyzes the photooxidation of water to molecular oxygen, providing electrons to the photosynthetic electron transfer chain. The D1 and D2 chloroplast-encoded reaction center polypeptides bind cofactors essential for Photosystem II function. Transformation of the chloroplast genome of the eukaryotic green alga Chlamydomonas reinhardtii has allowed us to engineer site-directed mutants in which aspartate residue 170 of D1 is replaced by histidine (D170H), asparagine (D170N), threonine (D170T), or proline (D170P). Mutants D170T and D170P are completely deficient in oxygen evolution, but retain normal (D170T) or 50% (D170P) levels of Photosystem II reaction centers. D170H and D170N accumulate wild-type levels of PSII centers, yet evolve oxygen at rates approximately 45% and 15% those of control cells, respectively. Kinetic analysis of chlorophyll fluorescence in the mutants reveals a specific defect in electron donation to the reaction center. Measurements of oxygen flash yields in D170H show, however, that those reaction centers capable of evolving oxygen function normally. We conclude that aspartate residue 170 of the D1 polypeptide plays a critical role in the initial binding of manganese as the functional chloroplast oxygen-evolving complex is assembled.

Update on Hodgkin's disease.

Hodgkin's disease is a rare lymphoma usually diagnosed in adults presenting with painless lymphadenopathy. Treatment includes radiation therapy for early stages of the disease and chemotherapy for advanced stages. While the majority with Hodgkin's disease will be cured of their disease, patients must complete a period of therapy with risks of significant acute side effects and serious long-term complications. This article provides an overview of the natural history, diagnosis, and staging of Hodgkin's disease as well as a discussion about treatment modalities and associated complications.

The eyespot of Chlamydomonas reinhardtii: a comparative microspectrophotometric study.

The eyespot of Chlamydomonas reinhardtii is believed to utilize a rhodopsin-like pigment in its responses to light. This paper examines its eyespot by means of microspectrophotometry with the finding of an absorption spectrum with two bands, an A-band in the blue, and a B-band in the green. This spectrum is identical to that previously recorded from the eyespot of Euglena gracilis. As with Euglena the B-band was found to have dichroic character and its spectrum was similar to the absorption curve of rhodopsin. This A-B-spectrum was always recorded from a single granule in each cell. It is concluded that both E. gracilis and C. reinhardtii may utilize a rhodopsin-like pigment as the photopigment associated with the eyespot response to light. In both these algae a few particles in each cell were found whose spectra consisted of two other bands, C and D, blue- and red-shifted, respectively, relative to the eyespot A-B-bands. There is some reason to believe that the C-D-granules may also be involved in certain light-controlled activities of the cells.

Molecular and biophysical analysis of herbicide-resistant mutants of Chlamydomonas reinhardtii: structure-function relationship of the photosystem II D1 polypeptide.

Plants and green algae can develop resistance to herbicides that block photosynthesis by competing with quinones in binding to the chloroplast photosystem II (PSII) D1 polypeptide. Because numerous herbicide-resistant mutants of Chlamydomonas reinhardtii with different patterns of resistance to such herbicides are readily isolated, this system provides a powerful tool for examining the interactions of herbicides and endogenous quinones with the photosynthetic membrane, and for studying the structure-function relationship of the D1 protein with respect to PSII electron transfer. Here we report the results of DNA sequence analysis of the D1 gene from four mutants not previously characterized at the molecular level, the correlation of changes in specific amino acid residues of the D1 protein with levels of resistance to the herbicides atrizine, diuron, and bromacil, and the kinetics of fluorescence decay for each mutant, which show that changes at two different amino acid residues dramatically slow PSII electron transfer. Our analyses, which identify a region of 57 amino acids of the D1 polypeptide involved in herbicide binding and which define a D1 binding niche for the second quinone acceptor, QB of PSII, provide a strong basis of support for structural and functional models of the PSII reaction center.

Chromosome assignment of the owl monkey MOS and MYC gene loci.

Southern blot hybridizations of rodent x owl monkey hybrid DNAs with human cDNA probes allowed the mapping of the MOS and MYC gene loci to owl monkey chromosome 16 of karyotype VI (2n = 49 male/50 female) and to the homologous chromosome 15 of karyotype V (2n = 46). Synteny of MOS and MYC gene loci in both man and owl monkey suggests this chromosome segment's conservation in primates, contrasting with its disruption in the mouse.

Permissible limits of flexor digitorum profundus tendon advancement--an anatomic study.

Lacerations of the profundus tendon distal to the superficialis insertion can be treated by advancement of the proximal cut end of the tendon to its insertion. In the English-language literature, limits cited for the distance a profundus tendon can be safely advanced vary from 0.75 to 2.5 cm and appear to be based on clinical impressions. Our cadaver model suggested the degree of tendon advancement tolerable was 1 cm. A delicate balance exists in the profundus tendon system, and this should be considered when surgical advancement is contemplated.

Lack of the D2 protein in a Chlamydomonas reinhardtii psbD mutant affects photosystem II stability and D1 expression.

D1 and D2, two chloroplast proteins with apparent mol. wt of 32 000-34 000, play an important role in the photosynthetic reactions mediated by the membrane-bound protein complex of photosystem II (PSII). We have isolated and characterized an uniparental, non-photosynthetic mutant of Chlamydomonas reinhardtii and show that the mutation is in the chloroplast gene psbD, coding for D2. A 46 bp direct DNA duplication in the coding region of the mutant gene causes a frame-shift which results in a psbD transcript coding for 186 amino acid residues instead of the normal 352. The truncated D2 peptide is never seen, even after pulse-labeling, suggesting that the mutant protein is very unstable. In addition, little or no D1 protein is detected in this mutant although the gene and normal levels of mRNA for D1 are present in mutant cells. All other core PSII proteins are synthesized and inserted into the membrane fraction, but never accumulate. These results suggest that D2 contributes not only to the stabilization of the PSII complex in the membrane, but also may play a specific role in the regulation of the D1 protein, either at the translational or post-translational level.

Variation among human 28S ribosomal RNA genes.

We report the complete 5025-base sequence of the human 28S rRNA gene. Variability within the species has been demonstrated by sequencing a variable region from six separately cloned genes. This region is one of three large subunit rRNA regions that show extreme sequence and size variation among species. The interspecies differences suggest species-specific functions for these sections, while the intraspecies heterogeneity indicates differences among ribosomes. Comparison of the human gene with a partial sequence from the chimpanzee 28S gene yields divergence rates for the two species: 0.8% for conserved regions of the gene and 3.7% for a variable region. The rapid divergence rates of variable regions in the ribosomal gene may permit answers to the question of time of separation of closely related species.

Herbicide resistance and cross-resistance: changes at three distinct sites in the herbicide-binding protein.

Plants and algae resistant to the commonly used s-triazine herbicides display a wide spectrum of cross-resistance to other herbicides that act in a similar manner. Analysis of uniparental mutants of the green alga Chlamydomonas reinhardi showed that three different amino acid residues in the 32-kilodalton thylakoid membrane protein can be independently altered to produce three different patterns of resistance to s-triazine and urea-type herbicides. These results clarify the molecular basis for herbicide resistance and cross-resistance. Two of the mutations do not alter normal electron transport and thus may have applications of agronomic interest.