Risk and protective factors for children''s substance use and antisocial behavior following parental divorce

Shape memory nickel-titanium (NiTi) alloys are potential candidates for biomedical applications. However, their equiatomic composition (50 wt% Ni) is controversial, and concerns have been raised about their biocompatibility level because of the carcinogenicity potential. The relative in vitro genotoxicity of NiTi therefore was evaluated and compared to commercially pure titanium (cpTi), 316L stainless steel (SS 316L), and positive and negative controls. To do so, human peripheral blood lymphocytes were cultured in semiphysiological medium that previously had been exposed to the biomaterials. The electron microscopy in situ end-labeling (EM-ISEL) assay then was performed in order to provide quantification of in vitro chromatin DNA single-stranded breaks (SSBs). Chromosomes and nuclei were harvested and exposed to exonuclease III, which amplifies DNA lesions at 3' ends of breaks. After random priming, incorporation of biotin-dUTP was labeled by immunogold binding, which then was detected using electron microscopy. Cellular chromatin exposed to the positive control demonstrated a significantly stronger immunogold labeling than when it was exposed to NiTi, cpTi, SS 316L extracts, or the untreated control. Moreover, gold particle counts, whether in the presence of NiTi, cpTi, or the negative control medium, were not statistically different. NiTi genocompatibility therefore presents promising prescreening results towards its biocompatibility approval.     

Suprascapular neuropathy after distal clavicle excision

Two cases of suprascapular neuropathy after excision of the distal clavicle are reported. Both patients were treated successfully with neurolysis of the suprascapular nerve starting at the upper trunk of the brachial plexus. Anatomic dissections revealed that the suprascapular nerve is quite close (<1.4 cm) to the posterior aspect of the distal clavicle, within 2 to 3 cm of the acromioclavicular joint. To avoid the complication of suprascapular neuropathy that could be associated with this close relationship, it is recommended that no more than 1 cm of the distal clavicle be removed posteriorly. It is also recommended that minimal periosteal elevation should be performed on the posteroinferior border of the distal clavicle.     

Anergic T cells actively suppress T cell responses via the antigen-presenting cell

We here show that anergic T cells are active mediators of T cell suppression. In co-culture experiments, we found that anergic T cells, derived from established rat T cell clones and rendered anergic via T cell presentation of the specific antigen (Ag), were active inhibitors of T cell responses. Anergic T cells inhibited not only the responses of T cells with the same Ag specificity as the anergic T cells, but were also capable of efficiently inhibiting polyclonal T cell responses directed to other epitopes. This suppression required close cell-cell contact between antigen-presenting cells (APC), anergic T cells and responder T cells, and only occurred when the epitope recognized by the anergic T cell was present. The suppression was not caused by passive competition for ligands on the APC surface, IL-2 consumption, or cytolysis, and was not mediated by soluble factors derived from anergic T cells that were stimulated with their specific Ag. When responder T cells were added 24 h after co-culturing anergic cells in the presence of Ag and APC, T cell responses were still suppressed, indicating that the suppressive effect was persistently present. However, anergic T cells were not able to suppress responder T cells that had already received a full activation signal. We propose that suppression by anergic T cells is mediated via the APC, either through modulation of the T cell-activating capacity of the APC (APC/T cell interaction), or by inhibition of T cells recognizing their ligand in close proximity on the same APC (T/T cell interaction).     

A histopathological, ultrastructural and immunohistochemical study of congenital hereditary retinoschisis

OBJECTIVE: To confirm our earlier histopathological and electron microscopic findings in congenital hereditary retinoschisis (CHRS) in two additional globes and to further evaluate the nature and origin of the intraretinal filaments by means of immunohistochemical analysis. PATIENTS: Three white men with CHRS, aged 83 years (patient I) (two globes), 55 years (patient 2) (two globes) and 33 years (patient 3, nephew of patient 2) (one globe). OUTCOME MEASURES: Findings on histopathological study and electron microscopy (patient I) and immunohistochemical analysis (all five globes). RESULTS: Histopathological examination showed extensive extracellular deposition of amorphous material positive for periodic acid-Schiff reagent in the outer schisis layer and focally in the macula. Ultrastructurally, the amorphous material represented filaments measuring 8 to 12 nm in diameter within degenerated Müller cells, with accumulation of these filaments in adjacent extracellular spaces. Similar, less severe changes were seen in the superonasal retina. Immunohistochemical studies showed focal reactivity for glial fibrillary acidic protein (GFAP) in the retina adjacent to the schisis cavity in all five globes, focal reactivity for S-100 protein in four retinas, rare focal staining for vimentin and neurofilaments in two retinas each and no reactivity for type I keratin or actin. CONCLUSIONS: The present study corroborates our previous work and provides pathological evidence that the retinal disorder extends beyond the limits of the schisis. The results of the immunohistochemical analysis are consistent with a glial cell origin of the filaments. We postulate that defective Müller cells produce GFAP and possibly S-100 protein, which accumulate within the retina and secondarily result in degeneration of these cells and schisis formation.     

Maternal hematologic changes during pregnancy and the effect of iron status on preterm delivery in a West Los Angeles population

This study was conducted to document the prevalence of anemia and high hematocrit during pregnancy and examine their effect on delivering preterm in a predominantly Hispanic population. The sample consisted of women receiving prenatal care from the public health clinics in the West Los Angeles from 1983 to 1986 (n = 7589). Multivariate logistic regression was used to isolate the role of anemia and high hematocrit from other factors that may influence birth outcome. The prevalence of anemia was approximately 9% at the initiation of prenatal care and at 28-32 weeks' gestation. Only anemia at 28-32 weeks was significantly associated with a preterm birth, even after adjusting for several confounders [Adjusted Odds Ratio (AOR) 1.83 95% Cl = 1.21, 2.77]. A high hematocrit that occurred in 9.6% of the population at 28-32 weeks was inversely associated with a preterm birth (AOR 0.78, 95% Cl = 0.44, 1.39). There was little differentiation of these risk factors when analyzing the etiological pathways of a preterm birth. These results indicate for the first time in a predominantly Hispanic population that despite routine iron supplementation, anemia still occurs in pregnant women and it can predict a preterm delivery.     

Calmodulin regulation of Ca2+ entry in Jurkat T cells

BACKGROUND: The authors have previously demonstrated abnormalities in glucose and insulin metabolism in nondiabetic black American (BA) adults versus white American (WA) adults. Whether similar glucoregulatory alterations extend to BA adolescents remain unknown. In addition, obesity, a known risk factor for insulin resistance and hyperinsulinemia, occurs in a greater proportion of BA adults and children when compared to WA. The objective of the present study was to examine the differential effects of obesity on glucose homeostasis in BA and WA adolescents. METHODS: We examined glucose homeostasis in BA and WA adolescents using oral glucose tolerance test (OGTT), intravenous glucose tolerance test (IVGTT), and [6,6-2H2]-glucose infusion. The study consisted of four age-, sex-, and pubertal stage-matched groups: 15 lean BA, 29 lean WA, 7 obese BA, and 9 obese WA. RESULTS: Both obese groups had significantly increased insulin and C-peptide area under the curve (AUC) during OGTT and IVGTT when compared to their same-race lean counterparts. During OGTT, obese BA demonstrated greater insulin and C-peptide when compared to obese WA. During IVGTT, first- and second-phase insulin were significantly greater in obese BA versus obese WA. CONCLUSION: In summary, BA adolescents demonstrated insulin resistance which is markedly exaggerated in the face of obesity when compared to WA adolescents, implying a differential impact for obesity on glucose homeostasis that is unique to the obese BA adolescent group. In conclusion, there is a need for early aggressive weight management in obese BA adolescents.     

The haemodynamic effect of thoracoscopic cardiac sympathectomy

A patient with angina pectoris who had been successfully treated by thoracoscopic cardiac sympathectomy was scheduled to have scalp debridement under general anaesthesia for a scald burn. There were haemodynamic changes during and after the operation including anaesthetic induction, endotracheal intubation, maintenance, and early recovery period. The sympathetic denervated heart showed little chronotropic response to anaesthetic and surgical stimulation. On the contrary, the parasympathetic response was predominant. An episode of severe bradycardia occurred during endotracheal suctioning prior to extubation. The haemodynamic response to cardiac sympathetic denervation corresponded to the efferent effect of beta-receptor blockade