Comparison of bone formation rates measured by radiocalcium kinetics and double-tetracycline labeling in maintenance dialysis patients

We report 23 prospective studies on 18 maintenance dialysis patients in whom we measured skeletal mineralization rate (m) using 47Ca, analyzed by the expanding pool model, and compared it with the histologic bone formation rate (bfr), volume referent, estimated on tetracycline-labeled iliac crest bone. The patients showed a spectrum of bone disease types including adynamic bone, aluminum-related osteomalacia, and various degrees of secondary hyperparathyroidism. The mean width between double labels, on which mineral apposition rate depended, was estimated using a simple formula relating area to perimeter for each feature enclosed by the labels. Values for m ranged from 0 to 155 mmol calcium per day and for bfr from 0 to 124% per year. There was close correlation between m and bfr (r = 0.976), serum alkaline phosphatase (r = 0.968), and serum immunological parathyroid hormone (iPTH) (r = 0.868). When the volumetric bfr was converted to mass units and applied to the whole skeleton, using literature values for mineral density and cortical and trabecular mass, there was close agreement between the histologic and isotopic estimates of m (r = 0.959). The results validate the two methods and suggest they are interchangeable. However, use of a rigorous method to determine bfr appears to be essential.     

Personality disorder correspondence among the MMPI, MBHI, and MCMI

MMPI, MBHI, and MCMI personality disorder scales were analyzed for convergent and discriminant validity. Friedman's ANOVA indicated that there were no significant differences among the sample's averaged scale scores. Further analyses of these data, however, demonstrated that the Millon instruments classified significantly more of the sample as personality disordered when compared to Morey's MMPI personality disorder scales. In addition, codetype correspondence among the three instruments was only 4 to 6%. When the instruments were analyzed in a pair-wise fashion, codetype correspondence increased to approximately 10 to 20%. These data indicate that these personality disorder scales do not demonstrate construct equivalence, particularly at the level of the individual profile.     

Voiding dysfunction in human immunodeficiency virus infections

PURPOSE: We prospectively evaluated the current spectrum of urodynamic pathology in patients infected with human immunodeficiency virus (HIV) who presented with voiding dysfunction. MATERIALS AND METHODS: We obtained a directed genitourinary and neurological history, and performed a physical examination and urodynamic testing in 18 patients. A 4-channel membrane urethral catheter was used to record intravesical and intraurethral pressures simultaneously. RESULTS: Detrusor hyperreflexia was present in 28% of our patients and detrusor-sphincter dyssynergia in 28%. Detrusor areflexia, previously described as the most frequent abnormality, was uncommon in our series (6% of patients). CONCLUSIONS: This changing proportion of urodynamic diagnoses may reflect a changing pattern of neurological manifestations of HIV infection due to more aggressive management. Urodynamic evaluation remains critical for precise diagnosis and treatment in patients with HIV who present with urinary symptoms.     

Hematocrit values in weight-selected and relaxed lines of White Rock chickens

Hematocrits (PCV) were measured at 29 and 106 d of age (PCV1 and PCV2, respectively) in male and female White Plymouth Rocks. Four lines were used, two of which had undergone 40 generations of divergent selection for 8-wk BW (HWS, LWS), and two respective sublines (HWR, LWR), in which selection had been relaxed for five generations. At both ages, males and females did not differ for PCV in lines HWR, LWR, and LWS. For line HWS there was an age by sex interaction that resulted from an age effect for males but not for females, and from a sex effect at each age. At both ages, PCV was higher for the HW than the LW lines. Initially, there was no difference between the selected and their respective relaxed lines, but by 106 d, HWR chickens had a higher PCV than HWS chickens. In lines HWR and LWR, PCV increased with age. There was a negative correlation in HWS males for PCV1 with 28 and 56 d BW. The HWR males also had a negative correlation for PCV1 with BW at 28 d, but not between PCV2 and BW. The correlation for PCV1 with PCV2 was high and positive for HWR males and females.     

On vitamin B1 metabolism in avitaminosis and its correction with thiamine and taurine

The levels of phosphate esters and the activities of thiamine biotransformation enzymes in the blood and tissues of albino rats were studied during oxythiamine-induced B1 deficiency and after metabolic correction with thiamine and taurine. Among thiamine phosphates, the most informative indicators of thiamine deficiency were shown to be triphosphate esters and free thiamine diphosphate. The biosynthetic enzymes thiamine kinase and thiamine diphosphate kinase played a decisive role in maintaining the initial rate and in recovering the physiologically active forms of vitamin B1. The activation of hydrolytic enzymes of thiamine phosphate esters occurred by producing abundant free thiamine diphosphate and thiamine triphosphate. Within the first hours, taurine favoured the acceleration of phosphoester biosynthesis and, accumulating in the tissues, inhibited vitamin phosphorylation reactions.     

Occurrence of dementia and depression in an elderly Danish population

A community survey of all Danish speaking residents above the age of 64 in a geographically delimited area was performed. The aim of the survey was to establish the prevalence of dementia disorders and depression by the use of international screening tools: the Mini Mental State Examination for dementia and the Beck's Depression Inventory for depression. The screening was performed during the period of one year in the municipality of Karlebo and the interviews took place in the homes of the participants. Six hundred and sixty-four (66%) of the 1,008 eligible persons entered the study. Six percent were residents in nursing homes. Thirteen point seven percent were found to be suffering from dementia. Nine point six percent had symptoms of depression. These prevalences would indicate that more than 6,000 persons in Frederiksborg county suffer from dementia while more than 4,000 might be suffering from depression. The study confirms knowledge obtained in other studies, indicating that one out of seven of the elderly suffers from dementia. We do not conclude, however, that nine point six percent suffer from depression, but rather that they need further examination to make it possible to decide whether they are indeed depressed.     

Retinal changes mimicking diabetic retinopathy in two nondiabetic, growth hormone-treated patients

A role for GH in the pathogenesis of diabetic retinopathy has long been postulated. Previous clinical studies, however, have been confounded by hyperglycemia. We have identified 2 cases of retinopathy associated with exogenous GH therapy in nondiabetic patients. Cases were identified through the MedWatch drug surveillance system of the U.S. Food and Drug Administration. Causality by concomitant medications was excluded by a search of the literature and the FDA data base. The first patient, an obese, 31-yr-old male with traumatic hypothalamic injury, presented with nonproliferative retinopathy and macular edema, resulting in decreased visual acuity (OD 20/40-1; OS count fingers), which required laser surgery. Human GH had been initiated at 0.009 mg/ kg.day, 14 months earlier, and titrated to 0.017 mg/kg.day. The second patient, a nonobese, 11-yr-old girl receiving GH for the management of short stature in Turner's Syndrome, presented with neovascularization. GH doses were 0.033 mg/kg.day for the first 17 months and 0.043 mg/ kg.day for the following 5 months. Cumulative laboratory and clinical observations suggest that GH and related peptides have a role in retinal pathology independent of the degree of glucose tolerance.     

A conserved mode of head segmentation in arthropods revealed by the expression pattern of Hox genes in a spider

Chelicerates constitute a basic arthropod group with fossil representatives from as early as the Cambrian period. Embryonic development and the subdivision of the segmented body region into a prosoma and an opisthosoma are very similar in all extant chelicerates. The mode of head segmentation, however, has long been controversial. Although all other arthropod groups show a subdivision of the head region into six segments, the chelicerates are thought to have the first antennal segment missing. To examine this problem on a molecular level, we have compared the expression pattern of Hox genes in the spider Cupiennius salei with the pattern known from insects. Surprisingly, we find that the anterior expression borders of the Hox genes are in the same register and the same relative segmental position as in Drosophila. This contradicts the view that the homologue of the first antennal segment is absent in the spider. Instead, our data suggest that the cheliceral segment is homologous to the first antennal segment and the pedipalpal segment is homologous to the second antennal (or intercalary) segment in arthropods. Our finding implies that chelicerates, myriapods, crustaceans, and insects share a single mode of head segmentation, reinforcing the argument for a monophyletic origin of the arthropods.