Use of an in ovo technique to provide adults of Levinseniella sp. no. 17 that were identified as Levinseniella minuta (Trematoda: Microphallidae)

One hundred and thirty surgical specimens of gastric adenocarcinoma were obtained from patients who had undergone radical gastrectomy. The samples were formalin-fixed, paraffin-embedded and used for immunostaining of Ki-67 antigen. Mean Ki-67 index was 41.8% (SD 15. 7%, range 8.2-84.2%). Differentiated carcinomas had a higher Ki-67 index than undifferentiated tumors, although other clinicopathological variables, including lymph node metastasis and depth of invasion showed no correlation with Ki-67 index. In the undifferentiated tumors, Ki-67 index correlated with lymph node involvement. A high Ki-67 index ( 55%) was found to be an independent indicator of poor prognosis in patients with undifferentiated tumors.     

Receptors of monoamine in sympathetic preganglionic neurons of neonatal rat spinal cord in vitro

By means of intracellular recordings from spinal cord slices of neonatal rats in vitro, the effects of 5-hydroxytryptamine (5-HT), nor-adrenaline (NA) and adrenaline (AD) on membrane potential in sympathetic preganglionic neurons (SPN) were observed, in order to clarify whether these neuron contain a single type of the monoamine receptor or in combination with more than one type of receptors. The results showed that: (1) 5-HT, NA and AD induced membrane depolarization respectively in 57.1% (16/28), 60% (15/25) and 52.4% (11/21) of SPN. (2) According to the reactions of SPN to the three monoamines, several subtypes of SPN could be divided: those sensitive to all the three monoamines (3/19), those sensitive to two of them (9/19), those only sensitive to one type of monoamines (4/19) and those insensitive at all (3/19). The significance of coexistence of more than one type of the three monoamines in a single neuron remains to be elucidated.     

Receptor-mediated endocytosis of angiotensin II in rat myometrial cells

The events involved in the processing of the angiotensin II (Ang II)-receptor complex were studied in primary cultures of rat myometrial cells. Ang II bound to rat myometrial cells in a specific, time- and temperature-dependent fashion. Pretreatment with cycloheximide did not interfere with binding up to 3 hr, but inhibited increases in binding observed over longer periods. The [3H]Ang II binding to intact cells was inhibited by dithiothreitol (DTT), and the rank order of potency of Ang II and nonpeptide antagonists to inhibit the [3H]Ang II binding was Ang II > Losartan > PD 123319 or CGP 42112B, indicating the presence of the AT1 receptor type. Whereas most of the [3H]Ang II binding at 4 degrees was susceptible to acid or pronase treatment, binding at 35 degrees was resistant to both treatments, suggesting an internalization of the Ang II-receptor complex. Phenylarsine oxide (PAO) and N-ethylmaleimide (NEM) caused a concentration-dependent inhibition when the binding assay was performed at 35 degrees, but no effect was observed at 4 degrees, indicating that these agents did not alter cell-surface binding but actually prevented the internalization process. Simultaneous treatment with 1 mM DTT or beta-mercaptoethanol prevented the inhibitory effect of NEM, but only DTT could prevent the inhibition caused by PAO, indicating that two closely located sulfhydryl groups must be involved in the internalization process. Chloroquine (100 microM) inhibited the [3H]Ang II dissociation from cells, and monensin (25 microM) induced a 30% inhibition of [3H]Ang II binding (35 degrees, 3 hr), suggesting endosomal processing of the Ang II-receptor complex with receptor recycling to the cell surface. These results indicate that Ang II binding to AT1 receptors in rat myometrial cells is followed by internalization of the Ang II-receptor complex and recycling of the receptor to the cell surface.     

In vivo sequence diversity of the protease of human immunodeficiency virus type 1: presence of protease inhibitor-resistant variants in untreated subjects

We have evaluated the sequence diversity of the protease human immunodeficiency virus type 1 in vivo. Our analysis of 246 protease coding domain sequences obtained from 12 subjects indicates that amino acid substitutions predicted to give rise to protease inhibitor resistance may be present in patients who have not received protease inhibitors. In addition, we demonstrated that amino acid residues directly involved in enzyme-substrate interactions may be varied in infected individuals. Several of these substitutions occurred in combination either more or less frequently than would be expected if their appearance was independent, suggesting that one substitution may compensate for the effects of another. Taken together, our analysis indicates that the human immunodeficiency virus type 1 protease has flexibility sufficient to vary critical subsites in vivo, thereby retaining enzyme function and viral pathogenicity.     

Effects of indomethacin on intragastric pH and meal-stimulated serum gastrin secretion in rheumatoid arthritis patients

The effects of oral indomethacin on intragastric pH and serum gastrin were investigated in rheumatoid arthritis patients. Nine patients (1 male, 8 female) without a history of peptic ulcer disease and 6 patients with a history of peptic ulcer disease (5 male, 1 female) were studied. To obviate Helicobacter pylori infection as a confounding factor, only patients with positive H. pylori serology were included. After a 5-day period of placebo treatment and after a 5-day period of indomethacin (50 mg t.d.s.; total dose 750 mg), 24-h intragastric pH and basal and meal-stimulated serum gastrin levels were measured in a double-blind placebo controlled cross-over study. There were no differences in the median 24-h pH values between placebo and indomethacin users irrespective of peptic ulcer disease history. Indomethacin resulted in a higher basal and stimulated gastrin response than placebo in patients with a history of peptic ulcer disease. The basal and incremental responses were lower in patients with a history of peptic ulcer disease than in patients without a history of peptic ulcer disease, both during indomethacin and placebo. The same basal and stimulated incremental serum gastrin responses were found during placebo and indomethacin treatment in patients without a history of peptic ulcer disease. No correlation was established between median 2-h post-prandial intragastric pH and post-prandial incremental serum gastrin concentration. We conclude that indomethacin does not influence the intragastric pH of rheumatoid arthritis patients irrespective of history of peptic ulcer disease.