[Changes in plasma neuropeptides before and after clonidine in patients with essential hypertension]

Plasma concentrations of beta-endorphin (beta-EP), leucine enkephalin (LEK), arginine vasopressin (AVP), neurotensin (NT), renin activity (PRA) and angiotensin II (AT-II) were determined before and after the treatment with clonidine in 117 patients with essential hypertension. Before the treatment, the patient group had lower levels of beta-EP and LEK (P < 0.001), higher levels of AVP, PRA and AT-II (P < 0.05-0.01), as compared with those in control group. After 14 days of the treatment, plasma levels of beta-EP, LEK increased significantly (P < 0.001), and correlated negatively with the decrease of the mean artery pressure (r = -0.369 and r = -0.441, respectively, P < 0.01). PRA and AT-II decreased significantly (P < 0.05, P < 0.01). Decrease of AVP level was also observed, but did not reach the statistical significance. NT did not change both before and after the treatment. These data suggest that beta-EP and LEK may be involved in pathogenesis of hypertension and in hypotensive action of clonidine.

Clonability and tumorigenicity of human epithelial cells expressing the EBV encoded membrane protein LMP1

Two isolates of the EBV-LMP1 gene were compared for their ability to induce phenotypic changes in a non-tumorigenic human keratinocyte line, Rhek-1, immortalized with an adenovirus 12-SV40 hybrid virus. One isolate, designated B-LMP1, was derived from B95-8, a B-cell line of marmoset origin, that carries a viral strain from a mononucleosis patient. The other, designated C-LMP1, originated from a nude mouse passaged Chinese NPC tumor, CAO. Both types of transfectants were less serum dependent than the non-transfected and the vector-transfected controls. The ability to grow on low serum increased with increasing LMP1 expression. All transfectants were more highly clonable than the non-transfected or vector-transfected controls. Clonability in soft agarose increased with increasing LMP1 expression. Nine of 24 C-LMP1 transfectants produced tumors in SCID mice. Seven of them grew invasively into the surrounding tissue. Only one of 12 B-LMP1 transfected Rhek-1 clones was tumorigenic. It did not grow invasively. All tumorigenic transfectants expressed LMP1 at high or moderate levels. All tumors were found to express LMP1. Transfectants with low LMP1 expression did not produce tumors. The untransfected Rhek-1 cells and six vector control clones failed to produce tumors.

Studies on etiological factors of nasopharyngeal carcinoma

A case-control study of nasopharyngeal carcinoma (NPC) was performed in Guangzhou, southern China in 1987 to 1989. We investigated 205 cases and an equal number of matched controls. Epstein-Barr virus (EBV) infection with positive IgA against viral capsid antigen (VCA-IgA) was shown to be the most important predictor in NPC. Consumption of salted fish was also strongly associated with NPC but not to the same extent as EBV. In order to investigate the possible carcinogenic effect of salted fish, Sprague-Dawley rats were given a diet containing salted fish for 2 years. Three rats with nasal and 3 with nasopharyngeal tumors were found in the experimental groups of 122 rats but none in the control group. Nitrosodimethylamine (NDMA) was found in kidney and liver but not in urine in the rats fed with salted fish. In a non-tumorigenic human keratinocyte line, RHEK-1, transfection of EBV latent membrane protein (EBV-LMP, originated from NPC cell line) induced alterations of morphology and immunophenotype. The LMP expressing sublines showed higher proliferative capacity and lower differentiation in vitro and some of the sublines produced tumors in SCID mice. When cultured in media containing salted fish extract in vitro parental RHEK-1 cells died after 12 weeks. In contrast, LMP expressing sublines survived indicating that exposure to some chemical compounds in salted fish and expression of EBV-gene may be of importance for the transformation of epithelial cells and thus for the pathogenesis of NPC.

GroEL, GroES, and ATP-dependent folding and spontaneous assembly of ornithine transcarbamylase

When purified rat liver ornithine transcarbamylase (OTC), a trimer of 36 kDa subunits, was denatured in 6 M guanidine hydrochloride and then diluted 50-100-fold, no activity was recovered, and the OTC subunits aggregated. In contrast, when the chaperonin groEL was included in the dilution buffer, OTC did not aggregate but instead comigrated in a sucrose density gradient with the groEL oligomer, indicating that a complex had been formed. Upon addition of the cochaperonin groES and ATP to the isolated OTC-groEL complex, OTC monomers were folded, released, and assembled into active trimer. Neither groES nor ATP alone was sufficient to release active OTC from groEL. The extent of recovery of activity was proportional to the concentration of the complex, reaching approximately 80-90% at monomer concentrations above 0.6 microM. At low complex concentrations, kinetic studies revealed an initial lag in the reconstitution reaction, suggesting that assembly is the rate-limiting step under these conditions. We could trap folded, released, inactive OTC monomers at early times that assembled into active trimers with longer incubation. A nonhydrolyzable ATP analog could release bound OTC from groEL in the presence of groES, but the OTC monomers were not competent for assembly. These data show that recovery of OTC activity in vitro can be efficiently directed by the bacterial chaperonins in the presence of ATP and suggest that the mechanism of reconstitution involves ATP and groES-dependent folding and release of OTC monomers from groEL, followed by spontaneous assembly of trimers.

A cellular automaton model of cancerous growth

A cellular automaton model describing immune system surveillance against cancer is furnished. In formulating the model, we have taken into account the microscopic mechanisms of cancerous growth, such as the proliferation of cancer cells, the cytotoxic behaviors of the immune system, the mechanical pressure inside the tumor and so forth. The model may describe the Gompertz growth of a cancer. The results are in agreement with experimental observations. The influences of the proliferation rate of cancer cells, the cytotoxic rate and other relevant factors affecting the Gompertz growth are studied.

[Cohort study of HIV infection among drug users in Ruili City and Longchuan County, Yunnan Province, China]

In March 1992, KAP investigation and HIV blood test were carried out for 860 drug users and 82 spouses in Ruili, Luxi, Longchuan of Yunnan Province, China. The results show that there were 285 IDUs (33.1%) among 860 drug users. Among 282 blood samples of IDUs, the HIV infection rate was 49.0%, highest in Ruili (81.8%, 63/77), then Longchuan (44.6%, 77/166), lowest in Luxi County (5.1%, 2/36). Twelve new HIV+ were found from 75 persons, who had been tested as HIV- in recent two years. Sixty-two blood samples were collected among 82 spouses of IDUs with HIV+, 6 were HIV+ (9.8%), with an increase of 6.7% comparing with results of the investigation two-years ago (3.1%, 2/64).

Valid estimation of IL2 secretion by PHA-stimulated T-cell clones absolutely requires the use of anti-CD25 monoclonal antibody to prevent IL2 consumption

A major problem encountered for quantification of IL2 production by stimulated T cells is its simultaneous consumption by these activated cells. In the present study, 40 T-cell clones (TCC) derived from normal peripheral blood, hyperplastic lymph nodes (LN) or lymph nodes involved by malignant lymphomas, were studied for their ability to produce IL2. When supernatants were generated in the presence of 20% fetal calf serum (FCS), no IL2 could be detected for 22 of the 40 TCC, whereas very low levels were found for the 18 other TCC (mean value 31 pg/ml; range from 10 pg/ml to 114 pg/ml); in contrast, when conditioned media were produced with reduced amounts of FCS (final concentration, 1%) as well as in the presence of an anti-CD25 monoclonal antibody (final concentration, 50 micrograms/ml), all TCC were found to release IL2, and very high quantities of this lymphokine were measured (mean value: 11,387 pg/ml; range, from 250 pg/ml to 37,000 pg/ml). Consequently, inhibition of IL2 consumption by PHA-stimulated TCC seems to be an absolute requirement for estimating the true capacity of T cells to produce this lymphokine.

Cloning of an apparent splice variant of the rat N-methyl-D-aspartate receptor NMDAR1 with altered sensitivity to polyamines and activators of protein kinase C

Molecular cloning identified complementary DNA species, from a rat ventral midbrain library, encoding apparent splice variants of the N-methyl-D-aspartate (NMDA) receptor NMDAR1 (which we now term NR1a). Sequencing revealed that one variant, NR1b, differs from NR1a by the presence of a 21-amino acid insert near the amino end of the N-terminal domain and by an alternate C-terminal domain in which the last 75 amino acids are replaced by an unrelated sequence of 22 amino acids. NR1b is virtually identical to NR1a in the remainder of the N- and C-terminal domains, at the 5' and 3' noncoding ends, and within the predicted transmembrane domains and extracellular and cytoplasmic loops. These findings suggest that the two forms of the receptor arise by differential splicing of a transcript from the same gene. Sequencing of other clones indicates the existence of a third variant, NR1c, identical to NR1b in its C terminus but lacking the N-terminal insert. NR1b RNA injected into Xenopus oocytes generated functional homomeric NMDA channels with electrophysiological properties distinct from those of NR1a homomeric channels. NR1b channels exhibited a lower apparent affinity for NMDA and for glutamate. NR1b channels exhibited a lower affinity for D-2-amino-5-phosphonovaleric acid and a higher affinity for Zn2+. The two receptor variants showed nearly identical affinities for glycine, Mg2+, and phencyclidine. Spermine potentiation of NMDA responses, prominent in oocytes injected with rat forebrain message, was also prominent for NR1a receptors, but was greatly reduced or absent for NR1b receptors. Treatment with the protein kinase C activator phorbol 12-myristate 13-acetate potentiated NMDA responses in NR1b-injected oocytes by about 20-fold; potentiation of NMDA responses in NR1a-injected oocytes was much less, about 4-fold. These findings support a role for alternate splicing in generating NMDA channels with different functional properties.

[The prognostic significance of plasma cyclic nucleotides in patients with congestive heart failure]

The relationship between plasma levels of cyclic nucleotides and mortality was studied in 108 patients with congestive heart failure (CHF) in whom plasma cAMP and cGMP, were determined by radioimmunoassay and were followed-up for 36 to 48 months. 29 patients died. The plasma concentrations of cAMP and cGMP in the dead group were significantly higher than those in the survival group (27.41 +/- 6.11 and 31.11 +/- 18.23 vs 21.56 +/- 5.37 and 17.45 +/- 9.35 nmol/L, respectively, mean +/- s, P < 0.001). Compared with patients with cAMP concentrations below the median value of 22.31 nmol/L, those with higher levels of cAMP had a higher mortality rate (46.3% vs 7.4%, P < 0.001). Patients with cGMP levels above the median value of 17.24 nmol/L also had a higher mortality rate than those with lower levels (40.7% vs 13.0%, P < 0.01). Multivariate stepwise regression analysis including age, cardiac function classification, heart rate, serum potassium and sodium, plasma cAMP, cGMP and cAMP/cGMP was carried out and revealed that only plasma cAMP and cGMP could provide independent prognostic information. Thus plasma levels of cyclic nucleotides was considered the excellent predictor for patients with CHF.

Accumulation of T-cell clones producing high levels of both granulocyte-macrophage and macrophage colony-stimulating factors (CSF-1) in lymph nodes involved by Hodgkin's disease

We have previously shown that total T cells derived from lymph nodes (LN) involved by Hodgkin's disease (HD) secrete higher levels of colony-stimulating activity than total T cells present within benign hyperplastic (BH) LN and B-non-Hodgkin's lymphoma (B-NHL) LN, suggesting that T cells with particular properties accumulate in HD LN. To further characterize this T-cell population, we have quantified production of both granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) production in a total of 98 T-cell clones (TCC) derived from CD25+ activated T cells present in HD LN; TCC derived from CD25+ T cells obtained from B-NHL LN(101 TCC), BH LN(95 TCC), and peripheral blood (PBL; 38 TCC) of healthy donors were used as controls. HD LN were characterized by the presence of an elevated number (44%) of TCC producing particularly high titers of both GM-CSF and M-CSF, whereas only a minority of such TCC was found in control groups (10% in B-NHL, 16% in BH, 8% in PBL). These observations support the hypothesis of a selection of T-cell families with particular properties occurring in contact with Reed-Sternberg (RS) cells. According to the biological properties of GM-CSF and M-CSF, it seems reasonable to suggest the involvement of this particular subset of T cells in the granulomatous process, the peripheral blood polynucleosis, and in the paracrine growth of RS cells.

Serotype diversity and antigen variation among invasive isolates of Ureaplasma urealyticum from neonates

Ureaplasma urealyticum has previously been isolated from the cultured cerebrospinal fluid of 13 of 418 newborn infants; additional bloodstream isolates were obtained from the same population. Ten of the 13 cerebrospinal fluid and 3 bloodstream isolates were available for serotyping in the present study. By the use of serotype-specific reagents, including monoclonal antibodies, 70% of the cerebrospinal fluid isolates were identifiable as serotype 1, 3, 6, 8, or 10; i.e., they represented 5 of the 14 established serotypes or both presently defined genomic clusters. One of the bloodstream isolates was identified as serotype 3. Our data support the hypothesis that the property of invasiveness for unreaplasmas is likely not limited to one or a few particular serotypes among the 14 established serovars. Additionally, our study has shown that even in isolates of the same serotype, there can be size variation in the antigens expressed. Therefore, it would appear that many serotypes are invasive and that perhaps antigen variability and host factors may be more important determinants for ureaplasma infections than different serotypes per se.

[Isolation and identification of Leclercia adecarboxylate in clinical isolates in China]

1987, 3 strains of gram-negative straight rods were examined from 3 cases of patients with diarrhea. It's producing yellow pigment, fermentative metabolism of carbohydrates, oxidase test negative and motility with the help of peritrichous flagella. Through systematic biochemical identification, calculation of G+C mol% and homology of DNA/DNA, the species of Leclercia adecarboxylate are identified. While the susceptibility to certain antibiotics and the pathogenicity for white mice are tested, and relation of these microorganisms to clinical diarrhea is discussed.

Changes of plasma immuno-reactive beta-endorphin content in patients with congestive heart failure and their clinical significance

Immunoreactive beta-endorphin (ir-beta-EP) content in plasma was measured by radioimmunoassay in 101 cardiac patients and 30 normal subjects. The results showed that plasma ir-beta-EP levels in patients of Class II (New York Heart Association Classification), Class III and Class IV were significantly higher than those in the normal group and those in patients of Class I (43.14 +/- 2.80, 54.25 +/- 4.47, 79.28 +/- 8.96 ng/L vs 24.23 +/- 2.13, and 24.98 +/- 3.35 ng/L, respectively, P less than 0.01). Plasma concentration of ir-beta-EP in patients complicated with atrial fibrillation was significantly higher than that in patients without atrial fibrillation (56.27 +/- 4.13 vs 44.66 +/- 3.41 ng/L, P less than 0.05). Ir-beta-EP contents in plasma were correlated positively to the cardiothoracic ratios (r = 0.63, P less than 0.001) and PEP/LVET ratios (r = 0.33, P less than 0.01), and were correlated negatively to the left ventricular ejection fraction and axis shortening (r = -0.41 and r = -0.39, P less than 0.001). These results indicated that plasma ir-beta-EP content may serve as a parameter in evaluating cardiac dysfunction.

Detection, isolation and functional studies of CD25+ T cells in lymph nodes involved by B-cell non-Hodgkin's lymphomas

We searched for the presence of IL2 receptor (CD25) on T cells as an activation marker in lymph nodes involved by B-cell non-Hodgkin's lymphomas (B-NHL). In 26 malignant lymph nodes studied, the number of CD25+ T cells among total T cells was usually low when assessed by immunofluorescence analysis (mean +/- SD: 6.7% +/- 11.2%), but greatly increased when an immunomagnetic rosette method was used (mean +/- SD: 17.5% +/- 16.6%). In six cases, CD25-/CD25/CD25+ cells were isolated by immunomagnetic separation, with a purity greater than 97% for both populations. Expansion of CD25-/CD25+ T cells was obtained with IL2 and PHA, then conditioned media (CM) were prepared. No IL2 activity was found in CM from both CD25-/CD25+ T cells when tested on CTLL2 cells. BCGF and BCDF mu/gamma activities were assayed on normal B cells stimulated with soluble or insolubilized anti-mu antibodies(BCGF) or with Cowan I (BCDF). Results of production of all these activities were comparable for both populations, and thus do not favour the possibility that CD25+ T cells closely associated with malignant B-NHL cells in lymph nodes may influence their proliferation (BCGF) or expression/secretion of heavy chain isotype (BCDF mu/gamma).

[Studies on the mutagenicity of vesnarinone]

The mutagenicity of domestic Vesnarinone (OPC-8212) was studied by Ames test, micronucleus test of NIH mouse bone marrow and chromosome aberration assay in CHL cells. Negative results were obtained, which suggested that OPC-8212 did not induce prokaryotic cell gene mutation or chromosome damage both in vitro and in vivo.

[Pathological observation of experimental asbestosis treated by hydroxy piperquin phosphate in dogs]

The paper presents experimental asbestosis treated with hydroxy piperquin phosphate (HPQP) in dogs. Results showed that the total cell number of bronchoalveolar lavage fluid, the viability of alveolar macrophages and the enzyme activities of lactate dehydrogenase, acid phosphatase and beta-glucuronidase of alveolar macrophages in treated dogs were higher than those in exposed dogs, asbestos fibers contents in the lungs and the mean scores of lung lesions in the treated dogs were markedly less than those in the exposed dogs. These findings support that HPQP may play a role in protecting alveolar macrophages from damage and inhibiting the progression of lung fibrosis, and that the clinical application of HPQP is somehow evidenced by this study.

Kainate activated single channel currents as revealed by domoic acid

We have studied the properties of kainic acid receptor-activated channels using domoic acid as an agonist. Similarities of the electrophysiological, pharmacological and noise properties of domoic acid and kainic acid-evoked currents confirm that domoate is a potent and specific agonist of the kainate receptor. Single-channel properties of domoic acid-evoked currents were directly determined from outside-out membrane patches for the first time, and results were compared with those obtained by fluctuation analysis of macroscopic currents. Small conductance cationic-selective channels of approximately 4 pS and a mean open time of 2 to 3 ms were detected using both methods.

The effect of in utero ethinyl oestradiol exposure on the risk of cryptorchid testis and testicular teratoma in mice

Epidemiological findings indicate that both cryptorchid testis and testicular germ cell cancer may be a result of high maternal oestrogen levels early in pregnancy. An experiment was conducted with a mouse strain (129 Sv-S1 C P) in which the males are susceptible to testicular teratomas to determine if the frequency of undescended testis and testicular teratoma in male offspring could be increased by administration of ethinyl oestradiol (EE) to pregnant mice before day 13 of gestation. This point in gestation marks the completion of the migration of germ cells to the gonadal ridge in mice and other studies with these mice have shown that the tumours are initiated in this critical time period. EE mixed with corn oil was administered by subcutaneous injection in doses of 0.02 (n = 76) and 0.2 (n = 102) mg kg-1 of body weight on gestational days 11 and 12. These mice were allowed to deliver their offspring and the males were killed at 15 days of age. Since the tumours are present from birth, this amount of time was allowed to permit the tumours to reach sufficient size for easy visual identification. Compared to controls (n = 63), who received corn oil alone, the treated mothers produced offspring who were significantly more likely to have a cryptorchid testis (P = 0.0001) and who had an increased risk, although not significant, of a testicular teratoma.

[Pharmacological studies of huomaisan]

After per os Huomaisan twice a day for 5 days, HMS significantly prolonged thrombus formation time and inhibited platelet aggregation induced by ADP and collagen. Meanwhile, HMS also decreased blood viscosity, but did not significantly affect hematocrit. The result shows that HMS has multiple actions on blood.

Evidence in a lethal infantile mitochondrial disease for a nuclear mutation affecting respiratory complexes I and IV

A child died at 4 months of age of a lethal infantile mitochondrial disease associated with cardiomyopathy. Detailed pathologic evaluation of this patient revealed abnormalities in the striated muscle, smooth muscle, heart, and liver, but not the central nervous system. Biochemical analysis revealed a combined complex I and IV deficiency in skeletal muscle, heart, and liver, but not in kidney and brain. Analysis of mitochondrial translation products and mitochondrial DNA failed to detect any abnormality. Parallel studies on both parents were uniformly normal. These data support the hypothesis that this disease was the result of a nuclear DNA mutation in a developmental stage-specific and tissue-specific oxidative phosphorylation-gene.

In vitro capacitation and fertilizing ability of ejaculated rabbit sperm treated with lysophosphatidylcholine

Four experiments were replicated 1) to establish dose-response relationships between lysophosphatidylcholine (LPC), sperm motility, and the acrosome reaction (AR), 2) to evaluate the influence of rabbit serum (RS) on these endpoints, 3) to compare buck differences in induction of the AR, and 4) to examine fertilizing ability in vitro of sperm tested under the first three objectives. Semen was collected from Dutch-belted rabbits, washed once by centrifugation, resuspended, and preincubated for 2 or 4 hr in a chemically defined medium (DM), DM plus 20% RS, or BSA-free DM plus 20% RS at 37 degrees C. At the end of preincubation LPC was added to the preincubated sperm at concentrations of from 0 to 100 micrograms/ml. Sperm were examined .5-4 hr later for AR and sperm motility. For in vitro fertilization, sperm and ova were coincubated in DM up to 24 hr after insemination and in a more complex medium for another 24 hr. Addition of LPC to 4-hr-preincubated sperm was more effective for inducing the AR than addition to 2-hr-preincubated sperm. A significant increase (P less than .05) in the AR occurred in 15 and 30 min following exposure to 100 and 80 micrograms of LPC per ml, respectively, but the higher concentration of LPC decreased sperm motility. Addition of 20% RS to DM with or without BSA surprisingly inhibited the AR but maintained sperm motility, as expected. Bucks differed (P less than .05) in the initial percentage and the induced percentage of AR sperm. For the AR the optimal concentration of LPC per ml was 80 micrograms, but for in vitro fertilization 60 micrograms tended to be superior.