Adult alveolar type II cells lack cAMP and Ca(2+)-activated Cl-channels

We investigated the presence of Ca(2+)-activated Cl-channels in adult rat alveolar type II (ATII) using patch-clamp techniques. Only one active channel each, with a single channel conductance of 50 pS and an opening probability (Po) of 0.76 was found among 130 successful cell-attached and 5 inside-out patches. Addition of CPT-cAMP into the bath (500 microM) induced one active patch from 33 silent cell-attached patches. Incubation of 9 ATII cells, with ionomycin (1 microM), failed to elicit chloride single currents in 9 cell-attached patches. Cl- currents were also absent from 35 whole cell patches, even after the addition of 10 microM terbutaline in the bath or 1 mM ATP and 5 mM MgCl2 in the pipette. These results indicate that only a very small fraction of adult rat ATII cells express CFTR and suggest that Cl- ions are passively transported across the cell junctions.

Field evaluation of the QBC technique for rapid diagnosis of vivax malaria

The QBC (quantitative buffy coat) technique was compared with that of the Giemsa-stained thick blood film (GTF) under field conditions in Junlian and Mingshan counties, Sichuan, China, for rapid diagnosis of vivax malaria. Blood samples were collected from 364 volunteer villagers, and each sample was examined with both the QBC and GTF techniques. For each GTF sample (10 microliters of blood), as many as 300 oil-immersion fields were examined; each QBC tube was inspected for up to 5 minutes. The GTF technique resulted in 86 positive blood samples and 278 negative; the QBC technique indicated 89 positive and 275 negative samples. Relative to the results obtained with GTF, the QBC technique had a sensitivity and specificity of 87.2% and 95.0%, respectively; concordance between the tests was 93.1%. The median time-to-positive diagnosis with the QBC technique (1.12 min) was 11% of that with GTF. The distribution of different developmental stages of Plasmodium vivax parasites was also examined in the centrifuged QBC tubes: all stages except schizonts could be found in the lower part of the platelet zone (the interphase between the monocyte and platelet layers), especially ring forms.

Apolipoprotein E genotype distribution in schizophrenia

We examined the hypothesis that apolipoprotein E (apoE) isoforms-besides their well-established role in the aetiology of early and late onset Alzheimer's disease (AD)-may be involved in the development of schizophrenia. We determined apoE genotypes in 98 schizophrenic patients and 98 sex and age matched controls. No significant difference in apoE allele frequencies were observed between schizophrenic patients, subpopulations of schizophrenics, or controls. There was also no difference in the mean age at onset depending on the number of apoE epsilon 4 alleles found in the patients. Our data do not support an association between AD and schizophrenia based on apoE acting as a common denominator in the pathogenesis of both diseases.

[Clinical application of intraoperative sustained limited expansion]

Since May 1993, the technique of intraoperative sustained limited expansion (ISLE) had been applied clinically in 21 cases for the immediate reconstruction of soft tissue defects. Satisfactory results were obtained in 18 cases (85.7%), and failed in 3 cases (14.3%). ISLE had been applied successfully in various regions of the body. It had been shown that the results were dependent on the extent of soft tissue defect, the extent of intraoperative tissue gain, and the time of intraoperative sustained expansion.

[A role of oblique flashlight test in screening for primary angle closure glaucoma]

PURPOSE

To study the effect of oblique flashlight test in screening for primary angle closure glaucoma.

METHOD

Two hundred adults over 50 years old were sampled randomly at Doumen county of Guangdong province in 1995. 390 eyes were measured by oblique flashlight test according to grading standard photos of oblique flashlight test. Other ocular examinations consisted of intraocular-pressure measurement with Schiotz tonometer, gonioscopy, and optic disc appearance.

RESULTS

The result showed 25.2% of the examined eyes had the oblique flashlight grade < or = 2, and tended to be increasing with age (x2 = 8.597, P < 0.05) and in females (x2 = 14.89, P < 0.01). Based on temporal anterior chamber angle < or = 2 (Shaffer's grade), the obligue flashlight grade < or = 2 found that occludable angle sensitivity was 91.7%, specificity was 91.5%, and 8.16% of the eyes had primary closure angle glaucoma. No patient was found in oblique flashlight grades > or = 3.

CONCLUSION

This study shows that oblique flashlight test conforms to screening test needs, and plays an important role in screening for primary closure angle glaucoma. We suggest that oblique flashlight grades < or = 2 as cutoff point of screening for occludable angle.

Changes of plasma dynorphin levels before and after percutaneous balloon mitral commissurotomy in patients with mitral stenosis

Plasma dynorphin A1-13 levels were measured in 33 patients with mitral stenosis before and after percutaneous balloon mitral commissurotomy (PBMC). The results show that the basal levels of plasma dynorphin in blood from the antecubital vein in the patients were significantly higher than those in 31 healthy control subjects. The increase in circulating dynorphin closely correlated with the functional cardiac status and the presence of atrial fibrillation. Ten to fifteen minutes after PBMC, plasma dynorphin levels in blood from the femoral vein increased significantly. Seventy-two hours after the procedure, the levels of plasma dynorphin in blood from the antecubital vein had decreased significantly, but they did not decrease to the normal range. Plasma dynorphin levels in blood from the femoral vein were positively correlated with the mean left atrial pressure and the mean right atrial pressure before the first balloon inflation. Plasma dynorphin levels in blood from the antecubital vein were positively correlated with the heart rate and the mean transmitral pressure gradient, and negatively with the mitral valve area before and 72 hours after PBMC.

[Clinical application of MRI in ophthalmic field]

PURPOSE

To investigate the application of MRI in ocular diseases and analysis the character of MRI-s parameters in these diseases.

METHODS

MRI was applied among 68 patients with neurophthalmic disorders, orbits diseases, and intraocular lensions.

RESULTS

The position (location) and feature of the lesions were diagnosed with clinical analysis.

CONCLUSION

MRI possesses the special value in the differentiation diagnosis of neurophthalmic disease, orbit disordes and intraocular conditions.

Changes of plasma beta-endorphin levels before and after percutaneous transvenous mitral commissurotomy in patients with mitral stenosis

To clarify the contribution of left atrial pressure to the secretion of beta-endorphin, we have investigated the relation between plasma beta-endorphin levels and hemodynamic changes in 35 patients with mitral stenosis undergoing percutaneous transvenous mitral commissurotomy (PTMC). Before PTMC, plasma beta-endorphin levels obtained from the antecubital vein (28.91 +/- 5.59 pg/ml) and from the femoral vein (28.20 +/- 5.44 pg/ml) in the patients with mitral stenosis were significantly higher than those obtained from the antecubital vein in the healthy volunteers (22.59 +/- 3.86 pg/ml, n = 34, P < 0.001 for each). The levels of beta-endorphin in the femoral vein correlated well with the mean left atrial pressure (r = 0.777, P < 0.001) and the mean right atrial pressure (r = 0.450, P < 0.01) before the procedure. The antecubital venous levels of beta-endorphin in patients in New York Heart Association functional Classes II (26.45 +/- 5.39 pg/ml, n = 20) and III (32.20 +/- 4.02 pg/ml, n = 15) were significantly higher than those in control subjects (P < 0.005 and P < 0.001, respectively). The differences between Classes II and III were significant (P < 0.001). The plasma levels of beta-endorphin in the patients complicated with atrial fibrillation were also significantly higher than those in patients with normal sinus rhythm (33.31 +/- 3.22 pg/ml, n = 13 vs 26.32 +/- 5.07 pg/ml, n = 22, P < 0.001). In ten to fifteen minutes after commissurotomy, plasma levels of beta-endorphin in the femoral vein significantly increased from 28.20 +/- 5.44 to 33.14 +/- 5.72 pg/ml (P < 0.001). In seventy-two hours after the procedure, plasma beta-endorphin levels in the antecubital vein fell to 24.37 +/- 2.59 pg/ml (P < 0.001 vs before PTMC and P < 0.05 vs control subjects). Plasma beta-endorphin levels in the patients with atrial fibrillation (26.62 +/- 2.36 pg/ml, P < 0.001 vs before PTMC and P < 0.002 vs control subjects) were still higher (P < 0.001) than those in patients with normal sinus rhythm (23.05 +/- 1.65 pg/ml, P < 0.001 vs before PTMC and P > 0.50 vs control subjects. There was a significant correlation between the levels of beta-endorphin in the antecubital vein and heart rate (r = 0.502, P < 0.001), mean transmitral pressure gradient (r = 0.543, P < 0.001) or mitral valve area (r = -0.710, P < 0.001) before and 72 hours after the procedure.

[Effects of resuscitation with hypertonic sodium lactate dextran 70 on cardiac function in severely burned dogs]

This comparative study was performed to evaluate the effects of resuscitation of burn shock with hypertonic sodium lactate dextran 70(HLD solution: Na+250 mmol/L and 6% dextran 70) and lactate Ringer' solution on cardiac function, lipid peroxide and SOD activity of heart tissue. Dogs with 35% TBSA third degree burns received, one hour postburn, either HLD resuscitation (HLD group, n = 6) in the amount of 19.6 ml.kg-1/g hours, followed by LR 6 ml.kg-1/% TBSA, or LR resuscitation (LR group, n = 6) in the amount of 8 ml.kg-1/% TBSA LR solution. The results of this experiment showed that cardiac index (CI) of HLD group was much higher than that of LR group at 4, 8, 12, 24 hours postburn. The dp/dt max and-dp/dt max of HLD group were much higher than that of LR group at 12.24 hours postburn. Level of MDA in heart tissue of HLD group (1.74 +/- 0.28 10 mol/g heart tissue) was much lower than of LR group (3.23 +/- 0.56 10 mol/g heart tissue) at 24 hours postburn (P < 0.01). Meanwhile, SOD activity in heart tissue of HLD group (157.49 +/- 32.23 u/mg heart tissue) was much higher than that of LR group (46.88 +/- 16.28 u/mg heart tissue) (P < 0.01). These results suggested that HLD resuscitation might be beneficial in improving postburn cardiac function and attenuating postburn oxidant-induced lipid peroxidation in heart tissue not only by its "oxygen scavenger" effect, but also by its elevation of SOD activity of heart tissue.

Effects of axial ligand replacement on the redox potential of cytochrome c

The formal potentials (E0') and electron transfer numbers (n) of imidazole (Im), 1-methylimidazole (1-MeIm), and 1-ethylimidazole (1-EtIm) complexes of cytochrome c have been determined for the first time using optically transparent thin-layer spectroelectrochemistry. In comparing these results with the E0' value of the cytochrome c, their potentials at infinite dilution have been calculated, which indicate that axial replacement of methionine-80 by Im, 1-MeIm, and 1-EtIm gives rise to 426, 359, and 327 mV negative shifts relative to that of native cytochrome c, respectively. Thereby, the origins of the effects of axial substitution on redox potential are discussed.

Overexpression of p53 predicts organ preservation using induction chemotherapy and radiation in patients with advanced laryngeal cancer. Department of Veterans Affairs Laryngeal Cancer Study Group

A critical research frontier in head and neck oncology involves defining the use of induction chemotherapy regimens to allow organ preservation and to avoid functionally debilitating surgical resections. Completed clinical trials in laryngeal cancer indicate that such an approach is feasible, but progress thus far has been limited by our inability to predict which patients are likely to respond to chemotherapy and preserve their larynx. Mutation of the p53 tumor-suppressor gene is the most common genetic alteration identified thus far in human cancers, and it may be important in regulation of cell proliferation and chemosensitivity. To determine whether p53 overexpression predicts chemotherapy response, organ preservation, and survival in patients with advanced laryngeal cancer, we analyzed immunohistologic expression of p53 in tissue sections from 178 patients with advanced laryngeal cancer who were entered in the Department of Veterans Affairs Laryngeal Cancer Cooperative Study, a multiinstitutional clinical trial comparing induction chemotherapy (cis-platinum and 5-fluorouracil) plus radiation therapy (94 patients) to surgery plus postoperative radiation therapy (84 patients). Larynx preservation was significantly higher in the group of patients whose tumors overexpressed p53 (74% vs. 52.5%; p = 0.03). The presence of p53 overexpression did not predict survival in either the surgery or the chemotherapy groups (p = 0.82 and p = 0.53).

The crystal structure of deshexapeptide (B25-B30) insulin at 0.25 nm resolution

The determination of deshexapeptide (B25-B30) insulin (DHI) was divided into two steps. At the first step, the rough structure model of DHI molecule was determined by using the molecular replacement method associated with the molecular close-packing method at 0.30 nm resolution based on the reflection data collected on four-cycle diffractometer. At the second step, the DHI model was adjusted and refined at 0.25 nm resolution based on the data collected on Area Detector. 40 water molecules were determined during the refinement, the final R-factor is 0.185 with R.M.S. deviation of 0.002 nm for bond lengths and 1.9 degrees for bond angles. The differences in conformation and function of DHI with other insulin analogues were compared and discussed.

[Isolation of fusarium and extraction of its toxin from buckwheat grown in an area with "endemic breast enlargement" disease]

Fusarium was isolated and its toxin was extracted from the buckwheat grown in an epidemic area with "endemic breast enlargement" disease. The toxin was determined with thin layer chromatography and mass spectrography. Results showed there were more than four kinds of mould, including fusarium, isolated from buckwheat grown in the endemic disease area. All the buckwheat grown in the area were infected with mould and 34% with fusarium. Three kinds of toxin were extracted from the buckwheat, with rates of flow of 0.23, 0.47 and 0.90, respectively, in thin layer chromatography. And, zearalenone was extracted from the buckwheat and identified by mass spectrography.

The histidyl-tRNA synthetase-related sequence in the eIF-2 alpha protein kinase GCN2 interacts with tRNA and is required for activation in response to starvation for different amino acids

Protein kinase GCN2 is a multidomain protein that contains a region homologous to histidyl-tRNA synthetases juxtaposed to the kinase catalytic moiety. Previous studies have shown that in response to histidine starvation, GCN2 phosphorylates eukaryotic initiation factor 2 (eIF-2), to induce the translational expression of GCN4, a transcriptional activator of genes subject to the general amino acid control. It was proposed that the synthetase-related sequences of GCN2 stimulate the activity of the kinase by interacting directly with uncharged tRNA that accumulates during amino acid limitation. In addition to histidine starvation, expression of GCN4 is also regulated by a number of other amino acid limitations. Questions that we posed in this report are whether uncharged tRNA is the most direct regulator of GCN2 and whether the function of this kinase is required to recognize each of the different amino acid starvation signals. We show that GCN2 phosphorylation of eIF-2, and the resulting general amino acid control pathway, is stimulated in response to starvation for each of several different amino acids, in addition to histidine limitation. Cells containing a defective aminoacyl-tRNA synthetase also stimulated GCN2 phosphorylation of eIF-2 in the absence of amino acid starvation, indicating that uncharged tRNA levels are the most direct regulator of GCN2 kinase. Using a Northwestern blot (RNA binding) assay, we show that uncharged tRNA can bind to the synthetase-related domain of GCN2. Mutations in the motif 2 sequence conserved among class II synthetases, including histidyl-tRNA synthetases, impair the ability of this synthetase-related domain to bind tRNA and abolish GCN2 phosphorylation of eIF-2 required to stimulate the general amino acid control response. These in vivo and in vitro experiments indicate that synthetase-related sequences regulate GCN2 kinase function by monitoring the levels of multiple uncharged tRNAs that accumulate during amino acid limitations.

[Gene diagnosis of adult polycysitic kidney disease--using polymorphic microsatellite markers]

Gene diagnosis of adult polycystic kidney disease (APKD) is possible by genetic linkage analysis using linked restriction fragment length polymorphisms (RFLP) on both sides of the PKD1. This technique is laborious, expensive and sample- time- consuming. SM7 is a polymorphic microsatellite that tightly linked with the PKD1. We combined PCR with polyacrylamide gel electrophoresis and method of gel Ag+ staining to detect the allelus and genotype frequencies of the microsatellite amplificated in unrelated Chinese population. The study of 8 APKD families with SM7 demonstrated that the technique is quite simple, fast, sensitive and does not require the use of radioisotopes and ultraviolet. It could provide a powerful method for the presymptomatic and prenatal diagnosis of APKD.