Striatal cells containing the Ca2+-binding protein calretinin (protein 10) in ischemia-induced neuronal injury

The present study concerns the vulnerability of striatal interneurons immunopositive for the Ca²⁺-binding protein calretinin to ischemic neuronal injury. An immunohistochemical study was carried out on the striata of rats which had undergone transient middle cerebral artery occlusion. Two weeks after the ischemia, there was a marked reduction in the number of calretinin-positive neurons in the ipsilateral ischemic lesion, although the striatal interneurons positive for parvalbumin, which are a neuronal population distinct from the calretinin-immunoreactive cells in the striatum, were spared in the insulted areas. The present data indicate that the striatal calretinin-positive neurons are less resistant to transient ischemia, suggesting that there may exist vulnerability differences among the striatal interneurons in ischemia-induced neuronal injury.     

Noninvasive Nasal Mask BiPAP Management for Prolonged Respiratory Failure Following Cardiovascular Surgery

A bstract The purpose of this study was to assess the efficacy of nasal mask bi-level positive airway pressure (BiPAP) support in managing respiratory failure following cardiovascular surgery. A total of 20 patients requiring postoperative prolonged respiratory support of 72 hours or longer were studied. BiPAP support was used for eight patients (BiPAP group); the other 12 patients were managed using ordinary oxygen mask treatment (control group). The mean age of the BiPAP group and control group was 65 and 58 years of age, respectively. The mean period of postoperative endotracheal intubation of the BiPAP group and control group was 12 ± 5 days and 7 ± 1 days, respectively. Reintubation was necessary in two patients of the control group. The BiPAP group patients required no reintubation. BiPAP support was discontinued within 48 hours in 6 out of 8 patients. The respiratory rates of control group increased (p < 0.1) 24 hours after extubation, however, the respiratory rates of the BiPAP group remained unchanged. The values of the respiratory index of the BiPAP group improved significantly (p < 0.01) after BiPAP management (from 1.5 ± 0.2 to 0.9 ± 0.2). The values of the control group, however, remained unchanged. A-aDO₂ and Qs/Qt decreased (p < 0.1) in the BiPAP group. There were no significant differences in central venous pressure or circulatory status between the two groups. In conclusion, BiPAP support is a noninvasive management technique for postoperative respiratory failure and may also prevent prolonged endotracheal intubation.     

Study on distribution of epidermal growth factor (EGF) in rat tissues

Tissue distribution of epidermal growth-factor (EGF) in rat was investigated using a human EGF (hEGF) radioimmunoassay system. Antisera generated against hEGF reacted with hEGF and [21Leu] hEGF but not with mouse EGF, fibroblast growth factor (FGF), nerve growth factor (NGF), platelet derived growth factor (PDGF), and endothelial cell growth supplement (ECGS). Similar amounts of EGF immunoreactivity (EGF-IR) were found in the rat submandibular gland (32.8 +/- 4.59 ng/g tissue, n = 5) and duodenum (39.9 +/- 18.7 ng/g tissue, n = 9), whereas little EGF was detected in other tissues. No sex difference was observed in submandibular and duodenal EGF-IR, being different from the case of mouse in which ten times higher concentration of EGF-IR was found in male submandibular gland. Sephadex G-50 gel chromatography of submandibular and duodenal extracts revealed that each consisted of at least three different immunoreactive forms. The predominant EGF-IR was coeluted with 125I-EGF, significant amounts of EGF-IR was observed in the void volume fractions, and only small peaks of EGF-IR were present near Vt. These data clarified the presence of EGF-IR in rat submandibular and duodenal tissues and the molecular heterogeneity of EGF-IR and suggest some important role of EGF in the gastrointestinal function.     

T-cell acute lymphoblastic leukemia with add(1)(p36) and del(12)(p11) following acute myelocytic leukemia with partial deletion of 9p

We describe the case of a 40-year-old man whose disease was initially diagnosed as acute myelocytic leukemia. The patient achieved remission with chemotherapy, but relapsed shortly afterwards with an acute T-cell lymphoblastic leukemia. He died of intracranial bleeding. Karyotyping analysis showed a del(9p?) as a common abnormality in the leukemic cells at onset and relapse. Fluorescence in situ hybridization analysis demonstrated allelic loss of the CDKN2A gene in cells from both stages of the disease. At relapse the leukemia cells had additional abnormalities such as add(1)(p36) and del(12)(p11). We postulate that the loss of CDKN2A is involved in leukemogenesis but does not determine the lineage of the leukemic cells. Instead, abnormalities of genes at 1p36, 12p11, or both may be involved in driving a lymphoid phenotype.     

A nonsynonymous polymorphism in the human fatty acid amide hydrolase gene did not associate with either methamphetamine dependence or schizophrenia

Genetic contributions to the etiology of substance abuse and dependence are topics of major interest. Acute and chronic cannabis use can produce drug-induced psychosis resembling schizophrenia and worsen positive symptoms of schizophrenia. The endocannabinoid system is one of the most important neural signaling pathways implicated in substance abuse and dependence. The fatty acid amide hydrolase (FAAH) is a primary catabolic enzyme of endocannabinoids. To clarify a possible involvement of FAAH in the etiology of methamphetamine dependence/psychosis or schizophrenia, we examined the genetic association of a nonsynonymous polymorphism of the FAAH gene (Pro129Thr) by a case-control study. We found no significant association in allele and genotype frequencies of the polymorphism with either disorder. Because the Pro129Thr polymorphism reduces enzyme instability, it is unlikely that dysfunction of FAAH and enhanced endocannabinoid system induce susceptibility to either methamphetamine dependence/psychosis or schizophrenia.     

Decreased oxygen radical generation by neutrophils from patients with measles presumably owing to activation of suppressor T lymphocytes.

The capacity for the generation of oxygen radicals by polymorphonuclear leukocytes (PMNs) was assessed in 29 patients with measles and in control groups. Patients with secondary bacterial infections showed a significantly decreased generation of oxygen radicals; this abnormality did not persist for more than 2 months after disease onset. Normal PMNs incubated with T lymphocytes from these measles patients generated significantly fewer oxygen radicals than those incubated with T cells from either control group. However, normal PMNs incubated with non-T lymphocytes from these measles patients produced normal oxygen radical levels. In addition, irradiation above 1,500 rads of T lymphocytes abrogated the suppressive effect of T cells on PMNs. On the other hand, these abnormal findings were not observed in patients with measles but without secondary bacterial infections. The secondary bacterial infections sometimes seen in measles patients may result from a decrease in oxygen radical generation, presumably induced by the suppressive activity of the T lymphocytes of the patients.     

Coincident stimulation of convergent cortical inputs enhances immediate early gene induction in the striatum

The effect of coincident stimulation of convergent corticostriatal inputs was analyzed by the induction of immediate early genes in striatal neurons. Cortical motor areas were stimulated through implanted electrodes in awake, behaving rats, and the induction of the mRNAs encoding the immediate early genes (IEGs) c-fos and arc was analyzed in the striatum with in situ hybridization histochemistry. In the first experiment, unilateral stimulation of the medial agranular cortex, orofacial region of the lateral agranular cortex or the forelimb region of the lateral agranular cortex resulted in IEG induction in the striatum, which was restricted to the topographically related area receiving input from the stimulated cortical area. In a second experiment, stimulation parameters were altered, including frequency, number of pulses/train, and number of trains/s. These parameters did not have a significant effect on IEG induction. Notably, in some cases, in which there was IEG induction not only in the stimulated cortical region, but also in the homologous area in the contralateral hemisphere, very robust IEG induction was observed in the striatum. In a third experiment, the orofacial regions of the lateral agranular cortex of both hemispheres were stimulated coincidently. All of these animals showed robust striatal IEG induction. This IEG induction was attenuated by pretreatment with an NMDA antagonist MK-801. In a fourth experiment, we tested whether the coincidence of bilateral cortical stimulation contributed to the efficacy of striatal IEG induction. Either alternating stimulation or coincident stimulation of non-homologous cortical regions produced significantly lower striatal IEG induction than obtained with coincident stimulation of homologous cortical areas. Enhanced striatal IEG induction occurred in indirect striatal neurons, labeled with enkephalin, but was also present in a large number of enkephalin-negative neurons, most of which are likely direct pathway neurons. These results suggest that regional and temporal convergence of cortical inputs enhances striatal IEG induction.