Average African American three-dimensional computed tomography skull images: the potential clinical importance of ethnicity and sex

The production of average 'normative' three-dimensional (3D) computed tomography surface images of the bony skull has only recently been explored. The authors wish to determine the effect of using sex- and ethnicity-specific adult average 3D skull images for comparisons with patient images at various stages of craniofacial surgical management (i.e., diagnosis, treatment planning, prosthetic design, image-guided operative procedures, and outcomes assessment). Craniofacial surgical reconstruction for abnormal patterns of development, cancer resection, or trauma are most likely to benefit from these comparisons. To morphometrically test the significance of separating normative 3D skull data by sex and ethnicity, the authors collected 52 3D, anatomical landmarks from 3D computed tomography scans of dry skulls of 20 Americans of European ethnicity and 20 Americans of primarily African (i.e., primarily African and some European) ethnicity. A Procrustes-based morphometric analysis of shape detects 1.2 times as much interethnic variance as intersex variance. The African American sample presents 4.2% more dolichocephaly, wider orbits, flatter nasal area, larger gnathic anatomy, and more procumbent dentition. Pooling the sexes across both groups, it is seen that men tend to have less bulbous crania, more protruding brows, noses, and masticatory muscle attachments, and relatively less protrusive palettes and anterior mandibles. Despite a small sample size (N = 40), the authors' results are statistically significant (P approximately 0.001 overall) for both of the main factors, sex and ethnicity, separately.     

The transcriptional effects and DNA-binding specificities of 17beta-estradiol after dimethyldioxirane activation

We investigated the spatio-temporal brain activity on the time scale of several milliseconds related to the mental rotation task requiring judgements of hand orientation, using a whole-cortex MEG (magnetoencephalography) system. Neuronal activity in the visual cortex was observed approximately 100-200 ms from stimulus onset, and that in inferior parietal lobe followed (after 200 ms). Both of these activities showed a contralateral dominance to visual stimulus hemifield. Premotor activity started later than the inferior parietal lobe activity, and these activities partially overlapped. Activity in primary motor and/or motosensory areas was observed in some subjects. The whole-cortex neuromagnetic measurements provided the time course of activity in the human brain associated with the implicit motor imagery: visual cortex-->inferior parietal lobe<-->premotor cortex. This process is considered to be the transformation process of retinotopic locations into a body-centered reference frame necessary for the mental rotation task.     

Calf and disease factors affecting growth in female Holstein calves in Florida, USA

A prospective cohort study was undertaken to determine calf-level factors that affect performance (growth) between birth and 14 months of age in a convenience sample of approximately 3300 female Holstein calves born in 1991 on two large Florida dairy farms. Data collected on each calf at birth included farm of origin, birth date, weight, height at the pelvis, and serum total protein (a measure of colostral immunoglobulin absorption). Birth season was dichotomized into summer and winter using meteorological data collected by University of Florida Agricultural Research Stations. Data collected at approximately 6 and 14 months of age included age, weight, height at the pelvis, and height at the withers. Growth in weight and stature (height) was calculated for each growth period; growth period 1 (GP1) = birth to 6 months, and growth period 2 (GP2) = 6 to 14 months. Health data collected included data of initial treatment and number of treatments for the diseases diarrhea, omphalitis, septicemia, pneumonia and keratoconjunctivitis. After adjusting for disease occurrence, passive transfer of colostral immunoglobulins had no significant effect on body weight gain or pelvic height growth. Season of birth and occurrence of diarrhea, septicemia and respiratory disease were significant variables decreasing heifer growth (height and weight) in GP1. These variables plus farm, birth weight and exact age when '6 month' data were collected explained 20% and 31% of the variation in body weight gain and pelvic height growth, respectively, in GP1. The number of days treated for pneumonia before 6 months of age significantly decreased average daily weight gain in GP2 (P < 0.025), but did not affect stature growth. Treatment for pneumonia after 6 months of age did not significantly affect weight or height gain after age 6 months. Neither omphalitis nor keratoconjunctivitis explained variability in growth in either of the growth periods.     

Craniosynostosis

Primary craniosynostosis, the premature closure of one or more cranial sutures, occurs in up to one in 2,500 births. Secondary causes of craniosynostosis include disorders that lead to failure of brain development and conditions that influence bone metabolism. The craniosynostoses result in skull deformities and increased intracranial pressure as the developing brain is compressed. Clinical signs and symptoms depend on which suture or combination of sutures are involved. The etiology of craniosynostosis is believed to concern genetic abnormalities in fibroblast growth factors or their receptors, and the craniosynostoses can be associated with other congenital syndromes. The most important differential diagnoses are molding that occurs during birth in young infants, and positional molding that occurs as a result of excessive time spent in the supine position in older infants. The diagnosis may be confirmed by plain films of the skull, and surgical treatment is usually indicated to prevent neurologic complications.     

Morphophysiopathologic studies on the biology of myocardium in acquired valvulopathies

Myocardial lesions due to various valvulopathies were sampled during open heart surgery under extracorporeal circulation, and histologically, histoenzymologically and ultrastructurally investigated. Various cardiomyocitary and interstitial nonspecific progressive lesions, due especially to hemodynamic and hypoxic alterations, were identified. During the pathogenic stages, we remarked the onset and chronic evolution of perivascular and interstitial oedema, enhanced by a reduced lymph draining. The progressive processes of hyalinization, sclerosis and interstitial fibrosis were subsequent to the interstitial matrix modification. These processes accentuate the myocardial hypoxic lesion due to the nutritional and gaseous exchange alterations. The infrastructure, mitochondrial enzyme equipment, sarcoplasma and tubular network lesions, as well as the intramyocitary oedema that destroys the sarcomeric structure, ended with the activation of lysosome and lysosomal enzymes, giving rise to consequent cytolytic foci. Therefore, the process was extending. In this context, we remarked at the electronmicroscopic examination ventricular natriuremic granules, that are rarely mentioned in literature.     

Effect of glutathione depletion on exocyclic adduct levels in the liver DNA of F344 rats

The effects of glutathione (GSH) depletion on the in vivo formation of cyclic 1,N2- propanodexoxyguanosine adducts (AdG and CdG) as background lesions in the liver DNA of F344 rats were investigated. A group of 5 male F344 rats were given drinking water containing 30 mM L-buthionine (S,R)-sulfoximine (BSO) for 21 days, and another group of 8 rats were given only drinking water as controls. The BSO-treated rats had significantly lower weight gain than control rats. The hepatic GSH levels in the BSO-treated group were reduced by 84% as compared with the control group, from 4.43 to 0.72 mumol/g of tissue. The isomeric AdG3, CdG1, and CdG2 were detected by the 32P-postlabeling/HPLC method in the liver DNA of rats without carcinogen treatment, as we reported previously [Nath, R. G., and Chung, F.-L. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 7491-7495. Nath, R. G., et al. (1996) Cancer Res. 56, 452-456]. The mean levels (mumol/mol of guanine) for AdG3, CdG1, and CdG2 were 0.57 +/- 0.25, 0.15 +/- 0.18, and 0.16 +/- 0.22 for the control group and 1.18 +/- 1.03, 3.16 +/- 3.26, and 2.50 +/- 2.59 for the BSO group, respectively. These increases correspond to approximately 2-fold for AdG and 15-21-fold for CdG adducts. The dramatic increase in the cyclic adduct levels in rat liver DNA could have resulted mainly from GSH depletion as a result of the BSO treatment, even though other unknown effects due to the toxicity of BSO cannot be ruled out. These results suggest that GSH plays an important role in protecting the liver against cyclic propano DNA adduction and provide further support for the endogenous origin of these adducts.     

Improved survival of Hodgkin's patients in south-east Netherlands since 1972

In the past 30 years, staging and treatment of Hodgkin's disease have changed dramatically, and prolonged remission can now be induced in the majority of patients. Our purpose was to assess improvement in long-term survival, previously reported for specific patient groups, among unselected patients diagnosed and treated between 1972 and 1993 in general hospitals in South-East Netherlands. Data on all 345 Hodgkin's patients were derived from the population-based Eindhoven Cancer Registry; histopathology and clinical records were reviewed. Follow-up was attained up to 1994. Relative survival rates, i.e. the ratio of observed to expected rates, were 80% after 5, 70% after 10 and 67% after 15 years. Independent prognostic factors for lower overall survival were (in decreasing order of significance): advanced age, histology (lymphocyte depletion), advanced stage and earlier period of diagnosis. Distribution of age and stage did not change over the study period, but there was a modest increase in the incidence of the nodular sclerosis histological subtype. Crude 5-year survival rates improved from 60% in the period 1972-1976 to 81% in the period of 1987-1992 (P < 0.005). The largest improvement occurred in the 1970s and was most prominent among those aged over 50 years. As previously reported, cured Hodgkin's patients exhibit a higher mortality rate, which can be explained by treatment-related long-term complications such as second malignancies and cardiovascular diseases. The relatively high survival rates compared to other population-based studies may be attributable to the existence of a regional network within the framework of a comprehensive cancer centre. Better staging, new combinations of chemotherapy, improved radiation technology, advances in supportive care as well as more frequent intensive treatment of the elderly could explain the improvement in prognosis.     

Identification of a long variant of mRNA encoding the NR3 subunit of the NMDA receptor: its regional distribution and developmental expression in the rat brain

A longer variant of rat mRNA encoding the NR3 subunit of the NMDA receptor has been identified. It contains a 60-bp insertion at the nucleotide position 3007 in the intracellular domain of the C-terminal of the previously cloned variant. Therefore, the NR3 mRNA exists in at least two variants--with the insert (NR3-long; NR3-l) and without the insert (NR3-short; NR3-s). The NR3-l variant is expressed throughout the adult rat brain. Moreover, this variant predominates in the occipital and entorhinal cortices, thalamus and cerebellum. Analysis of NR3-l development indicates that it is regulated in a region-specific manner.     

Remote endarterectomy in SFA occlusive disease

Mice were exposed to interleukin- (IL-) 3 in vivo by injection of tumor cells transfected with the IL-3 gene. At 10 days post tumor injection, bone marrow cells were recovered, pulsed with particulate antigen in the form of ovalbumin (Ova)-coated magnetic beads, and tested for their ability to present antigen via class I to an Ova/class I-restricted T cell hybridoma. Cells from IL-3-stimulated mice exhibited a marked increase in antigen presentation compared with cells from mice injected with control non-cytokine-secreting tumor cells. These cells were markedly more efficient at presenting particulate Ova antigen than in presenting soluble Ova. Based on adherence, radiation resistance, and surface markers, the cells presenting antigen appear to be in the macrophage cell lineage. These cells are susceptible to lysis by antigen-specific cytotoxic T lymphocytes, which may contribute to limiting the effectiveness of antitumor responses.     

Coaxially stacked RNA helices in the catalytic center of the Tetrahymena ribozyme

Coaxial stacking of helical elements is a determinant of three-dimensional structure in RNA. In the catalytic center of the Tetrahymena group I intron, helices P4 and P6 are part of a tertiary structural domain that folds independently of the remainder of the intron. When P4 and P6 were fused with a phosphodiester linkage, the resulting RNA retained the detailed tertiary interactions characteristic of the native P4-P6 domain and even required lower magnesium ion concentrations for folding. These results indicate that P4 and P6 are coaxial in the P4-P6 domain and, therefore, in the native ribozyme. Helix fusion could provide a general method for identifying pairs of coaxially stacked helices in biological RNA molecules.