ACV synthetase

ACV synthetase (ACVS) is the first enzyme and plays a key role in the biosynthesis of all natural penicillins and cephalosporins. The enzyme is extremely unstable and little had been known about it until recently. This article summarizes the progress in research on this enzyme, including the establishment of a cell-free assay system, stabilization, purification, characterization, and gene cloning. A possible reaction sequence for ACVS catalysis is suggested.

Occupational hazards and pregnancy outcomes

This study examined the association between exposure to occupational hazards and pregnancy outcomes using data from a case-control study conducted in 29 hospitals in Shanghai, China. The sample included 1,875 perinatal deaths and newborns with birth defects and the same number of controls. Information on mother's exposure to occupational radiation, chemicals, noise, and pesticides was investigated. Logistic regression analysis controlling for potential confounders showed that exposure to radiation before/during pregnancy was associated with antepartum fetal death, birth defects, small-for-gestational-age (SGA), and threatened abortion. Exposure to chemicals before/during pregnancy was associated with antepartum fetal death, early neonatal death, birth defects, preterm birth, and threatened abortion. Women exposed to pesticides during pregnancy had an increased risk of SGA and threatened abortion. Exposure to occupational noise during pregnancy increased the risk of antepartum fetal death. Furthermore, higher than expected numbers of congenital anomalies in the central nervous system (CNS) were identified among women exposed to chemicals before pregnancy and to pesticides during the first trimester of pregnancy. No significant association was found between occupational exposure and intrapartum fetal death. Although recall bias may be possible in our study, the findings encourage further research.

Primary structure of the catalytic subunit of calf thymus DNA polymerase delta: sequence similarities with other DNA polymerases

The 125- and 48-kDa subunits of bovine DNA polymerase delta have been isolated by SDS-polyacrylamide gel electrophoresis and demonstrated to be unrelated by partial peptide mapping with N-chlorosuccinimide. A 116-kDa polypeptide, usually present in DNA polymerase delta preparations, was shown to be a degraded form of the 125-kDa catalytic subunit. Amino acid sequence data from Staphylococcus aureus V8 protease, cyanogen bromide, and trypsin digestion of the 125- and 116-kDa polypeptides were used to design primers for the polymerase chain reaction to determine the nucleotide sequence of a full-length cDNA encoding the catalytic subunit of bovine DNA polymerase delta. The predicted polypeptide is 1106 amino acids in length with a calculated molecular weight of 123,707. This is in agreement with the molecular weight of 125,000 estimated from SDS-polyacrylamide gel electrophoresis. Comparison of the deduced amino acid sequence of the catalytic subunit of bovine DNA polymerase delta with that of its counterpart from Saccharomyces cerevisiae showed that the proteins are 44% identical. The catalytic subunit of bovine DNA polymerase delta contains the seven conserved regions found in a number of bacterial, viral, and eukaryotic DNA polymerases. It also contains five additional regions that are highly conserved between bovine and yeast DNA polymerase delta, but these regions share little or no homology with the alpha polymerases. Four of these additional regions are also highly homologous to the herpes virus family of DNA polymerases, whereas one region is not homologous to any other DNA polymerase that has been sequenced thus far.(ABSTRACT TRUNCATED AT 250 WORDS)

[Alteration of erythrocyte biophysical properties in patients with ischemic cerebrovascular disorders]

Several erythrocyte biophysical properties (erythrocyte deformability, erythrocyte aggregation and erythrocyte electrophoretic mobility) were investigated in patients with cerebral infarction and in individuals with risk factors of stroke (RFS population; RFSP). Blood viscosity, plasma viscosity, hematocrit, plasma fibrinogen level and yield shear stress (YSS) were also tested. In comparison with the results in a control group, erythrocyte deformability (erythrocyte length under a certain constant shear stress and erythrocyte filterability) was less in both the patient group and the group of RFSP and there is an accompanying increase of erythrocyte aggregation. Blood viscosity and fibrinogen level were higher in the patient groups. There was no correlation between erythrocyte deformability and other hemorheological parameters. Our results suggest that significant alteration of erythrocyte biophysical properties may be implicated in the pathogenesis of ischemic stroke. These abnormalities are associated with some of the risk factors of stroke such as hypertension, atherosclerosis and cardiovascular disorders.

[Stimulation of the dorsal raphe nucleus induced depressive effect on cerebellar Purkinje cell responses to mossy and climbing fiber afferent inputs in rat]

In anaesthetized and paralyzed rats, the effect of dorsal raphe (DR) conditioning stimulation on cerebellar Purkinje cell (PC) responses to mossy fiber and climbing fiber inputs were examined. The main results are as follows: (1) Stimulation of cerebral sensorimotor cortex elicits widespread activation of mossy and climbing fiber inputs to PCs in contralateral VI and VII lobules of the cerebellum and generates two kinds of evoked responses, i.e. the simple spike (SS) and the complex spike (CS) responses with respectively a latency 8-25 and 12-30 ms. (2) These PC responses could be markedly suppressed by stimulation of DR at intensities which by themselves were subthreshold for directly affecting PC's spontaneous SS and CS activities. (3) This DR-induced depressive effects on evoked PC's SS and CS excitations could be attenuated or blocked by systemic administration of 5-HT receptor blocker methysergide. These results demonstrate that serotonergic fiber input from DR can suppress the efficacy of mossy and climbing fiber synaptic action on PC, or decrease the responsiveness of PC itself to afferent synaptic action. The findings of this study also suggest that the raphe-cerebellar serotonergic fiber afferent system may be involved in some of the important neuronal processing in the cerebellum.

[Pharmacological studies on the comparison between the drainage and certified Fel Ursi]

A comparison between the drainage and certified Fel Ursi was studied by pharmacological methods. The results demonstrated that the drainage Fel Ursi was similar to the certified products in anti-inflammatory, antipyretic, sedative, anticonvulsive, antispasmodic and bacteriostatic actions.

Reduction of aberrant crypt formation in the colon of CF1 mice by potential chemopreventive agents

Carcinogen-induced aberrant crypts (AC) of the colon are a precancerous state that leads to malignancy. The inhibition of AC formation by chemopreventive agents was evaluated in this study. Colon AC were induced by 1,2-dimethylhydrazine (DMH) in 3 weeks in CF1 mice. The cecum of the large intestine of CF1 mice did not produce more than one AC focus per animal. The effect of DMH and that of the inhibitors in this part of the large bowel were essentially similar to the vehicle control and inhibitor-only controls. The response of DMH treatment in the colorectal portion of the large bowel was found to be different from that of the cecum. The DMH treated mice had 13-17 foci per animal in three different experiments. The average number of AC per focus was greater than one in all three experiments performed. None of the inhibitor-only control animals nor the cottonseed oil vehicle control animals developed AC focus in the colorectal or the cecal part of the large bowel. The known inhibitor of colon carcinogenesis 3-butyl-4-hydroxyanisole reduced DMH-induced average AC formation by 10 and 46% at 1 and 4 mg per dose, respectively. The inhibitors 2-n-butylthiophene and phenylpropylisothiocyanate reduced DMH-induced average AC formation greater than 34 and greater than 40% respectively. The postulated inhibitor 2-n-octylthiophene, which is an eight-carbon homolog of 2-n-butylthiophene, similarly reduced DMH-induced AC formation. The known colon carcinogenesis inhibitor dehydroepiandrosterone, in contrast, has no effect. The inactivity of dehydroepiandrosterone to inhibit colon AC formation was attributed to its mechanism of inhibitory action, which differs from that of the phenol, isothiocyanate and thiophenes. The short duration that is required to produce quantifiable results suggests that the reduction of carcinogen-induced AC formation may be developed into a useful prescreening assay for potential chemopreventive agents against colon cancer.

Perinatal mortality in Shanghai: 1986-1987

The incidence of, and risk factors associated with, perinatal mortality in Shanghai during 1986-1987 are examined using data from a multi-site study conducted in 29 hospitals. The overall perinatal mortality rate was 14.96 per 1000 births. The mortality rates of antepartum fetal death, intrapartum fetal death and early neonatal death were 5.97, 2.06 and 6.94 per 1000 births, respectively. The perinatal mortality rates increased in winter and late spring. Male neonates were 1.5 times more likely to die than females. Low birthweight and preterm infants had 15 to 80 times higher risk of perinatal death. Higher parity, multiple pregnancy, and maternal age greater than or equal to 35 years were the risk factors for perinatal mortality. Asphyxia, cord complications, and congenital malformations were found to be the major causes of perinatal deaths. Comparison of mortality rates between Shanghai and the US suggests that the shortage of advanced technology in perinatal care (e.g. neonatal intensive care units) is a major obstacle to the reduction of perinatal mortality in Shanghai.

Sites of specific B cell activation in primary and secondary responses to T cell-dependent and T cell-independent antigens

Techniques which identify hapten-specific B cells in tissues have been used to determine the sites of B cell activation in rat spleens in response to T cell-dependent (TD) antigens and T cell-independent type-1 (TI-1) antigens. Surface-associated hapten binding by specific memory B cells and B blasts was distinguished from the strong cytoplasmic hapten binding by specific plasma cells and plasmablasts. Blast cells in S phase were identified in tissue sections by staining cells which had been pulse labeled in vivo with 5-bromo-2'-deoxyuridine. Hapten-specific B blast cells are found in three sites: (a) around interdigitating cells in the T cell-rich zones; (b) in the follicular dendritic cell network and (c) in association with macrophages in the red pulp. Hapten-binding memory B cells, which are not in cell cycle, accumulate in the marginal zones and to a lesser extent the follicular mantles in response to TD and TI-1 antigens. The hapten-specific blast response in T zones is confined to the first few days after antigen is given and is low for primary responses to TD antigens, but massive on secondary challenge, when marginal zone memory B cells migrate to the T zones. Both the primary and secondary T zone responses to TI-1 antigens are impressive and in these responses hapten-specific B blasts are also found in the splenic red pulp. The follicular response to TD antigens starts with a small number of B blasts (fewer than five) entering each follicle. These increase in number exponentially so that by the 4th day after immunization they fill the follicle. The oligoclonality of the response is shown in simultaneous responses to two haptens where 6%-31% of the follicles on day 3 after immunization contain blasts specific for only one of the two haptens. During the 4th day classical zonal pattern of germinal centers develops. The surface immunoglobulin-positive B blasts are lost from the follicle center, while one pole of the follicular dendritic cell network fills with surface immunoglobulin-negative centroblasts. Centroblasts do not increase in numbers but divide to give rise to centrocytes, which re-express sIg and migrate into the follicular dendritic cell network. Cell kinetic studies indicate that the centrocyte population is renewed from centroblasts every 7 h. Centrocytes either leave the germinal center within this time or die in situ.(ABSTRACT TRUNCATED AT 400 WORDS)

Severe vomiting during pregnancy: antenatal correlates and fetal outcomes

Neither the cause nor the effect of severe vomiting during pregnancy is well understood. This study examines possible causes of severe vomiting and associations between this disorder and fetal outcomes. One thousand eight hundred sixty-seven women with normal singleton live births were included in the analysis. The cumulative incidence of severe vomiting during pregnancy was 10.8%. Women with chronic liver disease had a threefold increased risk of severe vomiting during pregnancy. Paternal smoking was associated with a twofold increased risk of maternal vomiting. A modest association between severe vomiting and fetal growth retardation was identified (OR = 1.4, 95% CI: 0.9-2.3). Severe vomiting was also found to be associated with preeclampsia (OR = 1.5, 95% CI: 1.0-2.4). Our study indicates that passive smoking is a risk factor for vomiting during pregnancy, which may, in turn, increase the risk of fetal growth retardation.

Localization of functional projections from corpus callosum to cerebral cortex

In 30 patients with intractable generalized epilepsy treated with cerebral commissurotomy, the corpus callosum was stimulated intraoperatively at a 1 cm interval with electric current, and evoked potentials (EPs) were recorded from different areas of the brain for determining the distribution patterns of functional projections from the corpus callosum to the cerebral cortex. The surface of the corpus callosum in man was 12 cm long and it was divided into 12 segments (1 cm each). Stimulation of the first segment resulted in EPs only in the frontal lobe. Stimulation of segments 2-4 produced EPs mainly in the anterior, middle and posterior frontal lobe, anterior and central temporal lobe, rarely in parietal and occipital lobes. Stimulation of segments 5-8 induced EPs mainly in the frontal and temporal lobes, but rarely in the parietal and occipital regions; on stimulation of segments 9-11, EPs occurred only in the parietal and occipital regions. These results were confirmed electrophysiologically in 5 cats and anatomically in 8 cats. These data provide an anatomical basis for selective cerebral commissurotomy in the treatment of intractable epilepsy. Hence in patients with a concentration of epileptic discharges in the frontal lobe, the 4 anterior segments of the corpus callosum should be incised. Epileptic discharges in the frontotemporal region indicates that the middle segments should be incised and epileptic activities originating from the parieto-occipital regions can be treated effectively by selective section of the posterior corpus callosum (segments 9-12).

E1BF is an essential RNA polymerase I transcription factor with an intrinsic protein kinase activity that can modulate rRNA gene transcription

We previously described the purification and characterization of E1BF, a rat rRNA gene core promoter-binding factor that consists of two polypeptides of 89 and 79 kDa. When this factor was incubated in the absence of any exogenous protein kinase under conditions optimal for protein phosphorylation, the 79-kDa polypeptide of E1BF was selectively phosphorylated. The labeled phosphate could be removed from the E1BF polypeptide by treatment with calf intestinal alkaline phosphatase or potato acid phosphatase. Elution of the protein from the E1BF-promoter complex formed in an electrophoretic mobility-shift assay followed by incubation of the concentrated eluent with [gamma-32P] ATP resulted in the selective labeling of the 79-kDa band. The E1BF-associated protein kinase did not phosphorylate casein or histone H1. Fraction DE-B, a preparation containing RNA polymerase I and all polymerase I transcription factors (including E1BF), lost polymerase I transcriptional activity when treated with phosphatase. The phosphatase-induced inactivation of polymerase I activity associated with fraction DE-B could be reversed by the addition of purified E1BF. Treatment of purified E1BF with heat, SDS, or an ATP affinity analog eliminated its capacity to reactivate dephosphorylated fraction DE-B. These data demonstrate that (i) polymerase I promoter-binding factor E1BF contains an intrinsic substrate-specific protein kinase and (ii) E1BF is an essential polymerase I transcription factor that can modulate rRNA gene transcription by protein phosphorylation. Further, these studies have provided a direct means to identify a protein kinase or any other enzyme that can interact with a specific DNA sequence.

Protein kinase C regulates the stimulated accumulation of 3-phosphorylated phosphoinositides in platelets

We have shown that platelets stimulated with thrombin or guanosine 5'-[gamma-thio]triphosphate (GTP[S]), both of which activate phospholipase C and protein kinase C (PKC), show enhancement of 3-phosphorylated phosphoinositide accumulation (3-PPI). We now report the following. (1) Inhibition of thrombin- or GTP[S]-stimulated PKC by pseudo-substrate peptide (RFARK) added to permeabilized platelets markedly inhibits 3-PPI, whereas the serine/threonine phosphatase inhibitor, okadaic acid, promotes 3-PPI. PKC activity, insufficient in itself for fully activating 3-PPI, appears crucial to receptor and post-receptor stimulation of 3-PPI, even when tyrosine phosphorylation is unimpaired. (2) Alteration of Gi by ADP-ribosylation only slightly affects the stimulation of 3-PPI by thrombin, and activation of the G-protein Gi by adrenaline has no effect on 3-PPI. (3) Inhibition of PKC blocks activated secretion of platelet-derived growth factor (PDGF). However, PDGF cannot promote platelet 3-PPI, and thus cannot account for the inhibitory effects of RFARK on 3-PPI.

[Immunodiagnosis of ovarian cancer]

Ovarian tumor associated antigen was isolated from human serous cystadenocarcinomas of ovary and purified by using affinity chromatography columns coupled to anti-normal female serum and anti-normal ovarian tissue gamma globulin. Antiserum was prepared from New Zealand white rabbits. The antiserum was absorbed with normal female serum and extracts of normal ovarian tissue thoroughly. The absorbed antiserum was appraised by immunodiffusion, immunoelectrophoresis and counter-immunoelectrophoresis with intensifiers. The absorbed antiserum has a specific immune precipitin with extracts of ovarian tumor tissue. Counter-immunoelectrophoresis with intensifiers was used to detect the ovarian tumor associated antigen in the tissue and serum of various patients. Twenty-eight of 40 ovarian tumor extracts and 1 of 5 cervical carcinoma extracts showed the presence of the cancer antigen. 14/40 were positive in the sera of ovarian tumor patients and 6/10 positive in the sera of ovarian serous cystadenocarcinoma patients; 1/5 positive in the sera of cervical carcinoma patients and 2/10 positive in the sera of ovarian cysts patients. No positive result for the sera of normal females was noted. The specificity, sensitivity and accuracy of the method were 94.7%, 42.3% and 83.3%, respectively.

[Comparative study of menstruation in 240 healthy women at various altitudes]

To assess the relation of menstrual physiologic functions and altitudes, the authors made a comparative study of 240 healthy women with four diagnostic methods on traditional Chinese medicine and obtained their menstrual changes, picture of tongue and type of pulse in Xining (2260m) and Yushu Zhaduo (4300m). The results suggested that the menarche which occurred before 15 years old (P less than 0.005), the menstruation cycle of 16-25 days (P less than 0.05), and moderate quantity menstruation (P less than 0.005) are found more in the Xining group than in the Zhaduo group; the menstrual phase in the Xining group lasted 4-7 days and 1-3 in the Zhaduo group. The incidence of abdominal pain, cold, and lumbago increased significantly in the Zhaduo group and the symptoms were serious. The age of menostasia after 46 was 100% in the Xining group, whereas 27.3% of the Zhaduo group had menostasia at the age of 36-45. The colour of tongue varied from darker red to pink with increasing altitudes (P less than 0.005). Meanwhile, cases of rapid pulse increased (P less than 0.005). It is concluded that the physiology of menstruation for healthy women has obviously changed under high altitude hypoxic environment. The mechanism of pathology could be explained by dysfunction of Zang and Fu, deficiency of Qi, stagnation of blood and Qi stasis due to cold. Treatment and prevention of menstrual disorders of women at high altitudes could be carried out by invigorating Qi, regulating blood, promoting the flow of Qi, by warming the channel and regulating Zang and Fu, etc.

Influence of estradiol on the secretion of oxytocin and prostaglandin F2 alpha during luteolysis in the ewe

Twenty ewes of mixed breeds were randomly assigned in equal numbers to one of four groups in a 2 x 2 factorial design. The factors were x-irradiation to destroy ovarian follicles or sham irradiation and the administration of estradiol-containing or empty (placebo) implants. Surgery for irradiation was performed on Day 8 of the cycle. Blood samples were withdrawn from jugular catheters at 1.5-h intervals from Day 10 to Day 17. Luteolysis was not observed by Day 17 in 4 of 5 placebo-treated ewes after destruction of ovarian follicles. Luteolysis was observed in 4 of 5 ewes of the sham-irradiated, placebo-treated group and in all ewes that received estradiol whether or not ovarian follicles had been destroyed. The longest (p less than 0.07) interval between peaks of 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) was observed in the x-irradiated, placebo-treated group, whereas the administration of estradiol reduced (p less than 0.01) the interval between PGFM peaks. These findings indicate that a short interpulse interval in the secretion of prostaglandin F2 alpha (PGF2 alpha) is associated with luteolysis. It is possible that the reduced interpulse interval was either an effect of estradiol that caused luteolysis or a secondary event resulting from luteolysis. The administration of estradiol decreased (p less than 0.05) the number of episodes of oxytocin secretion during luteolysis and increased (p less than 0.01) the interval between episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical value of the Chengdu classification of non-Hodgkin's lymphomas]

Two hundred forty-nine cases of non-Hodgkin's lymphomas (NHL) were reviewed by using the working classification of NHL (Chengdu, 1985). The results showed that the patients of 249 cases of NHL ranging in age from 5 to 76 years, with the mean age of 42 of the types were separated into three major prognostic groupings as follows: 1. low (41 of 249 cases, small lymphocytic 27 cases, lymphoplasmacytoid 2 cases, follicular cleaved 7 cases, follicular cleaved and noncleaved 5 cases); 2. intermediate (58 of 249 cases, diffuse cleaved 28 cases, diffuse cleaved and noncleaved 27 cases, follicular noncleaved 3 cases); and 3. high grade malignancy (150 of 249 cases, diffuse noncleaved 49 cases, lymphoblastic 41 cases, immunoblastic 13 cases, polymorphic 39 cases, clear cell 2 cases, histiocytic 6 cases). Each group was significantly different from the others (P less than 0.05). The prognosis of patients with angioimmunoblastic lymphadenopathy like T-cell lymphoma (9 of 249 cases) was not more significant (P greater than 0.05) than that of patients with other polymorphic lymphoma (30 of 249 cases). The results showed this Chengdu classification of NHL is good for practice and usage in clinical evaluation and routine surgical pathology.

Prevention of H2O2 generation by monoamine oxidase protects against CNS O2 toxicity

Toxicity to the central nervous system (CNS) by hyperbaric oxygen (HBO) presumably relates to increased production of reactive oxygen species. The sites of generation of reactive oxygen species during HBO, however, have not been fully characterized in the brain. We investigated the relationship between regional generation of hydrogen peroxide (H2O2) in the brain in the presence of an irreversible inhibitor of catalase, aminotriazole (ATZ), and protection from CNS O2 toxicity by a monoamine oxidase (MAO) inhibitor, pargyline. At 6 ATA of oxygen, pargyline significantly protected rats from CNS O2 toxicity whereas ATZ enhanced O2 toxicity. In animals pretreated with ATZ, HBO inactivated 21-40% more catalase than air exposure in the six brain regions studied. Because ATZ-mediated inactivation of catalase was H2O2 dependent, the decrease in catalase activity during hyperoxia was proportional to the intracellular production of H2O2. Pargyline, administered 30 min before HBO, inhibited MAO by greater than 90%, prevented ATZ inhibition of catalase activity during HBO, and reversed the augmentation of CNS O2 toxicity by ATZ. These findings indicate that H2O2 generated by MAO during hyperoxia is important to the pathogenesis of CNS O2 toxicity in rats.

[The relationship of biochemical changes among bronchoalveolar lavage fluid serum and lung on dust-exposed rats]

The relationship between biochemical changes in bronchoalveolar lavage fluid (BALF), serum and the lung of different dustexposed rats was studied. Wistar rats were divided into 5 groups: 1. Xingkong chrysotile asbestos (CH-As); 2. Dust in a sieve selection workshop of Xingkong asbestos mine (Dust-Wo); 3. Silica group (SiO2); 4. Titanium dioxide (TiO2) and 5. Normal control group (Control). All the rats were killed in three months after experiment. The results showed that the level of alveolar macrophages (AM), lactic dehydrogenase (LDH) and acid phosphatase (AcP) in each group was marked by related to collagen, lung fat, ceruloplasmin (Cp) and hydroxyproline (HoP) by r and t-test. Among the LDH from BALF, culture fluid and serum, there was also a marked relationship. So the authors pointed out that the BALF especially AM and LDH test could serve as a good and valuable index for detection the condition of pneumoconiosis.

Suppression of luteinizing hormone secretion by atrial and brain natriuretic peptides in ovariectomized rats

Brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) are present in brain regions regulating LH secretion. Similarities in the molecular structure of these peptides suggest similar physiological function within the brain. This study examined the effects of centrally administered BNP and ANP on LH secretion in mature ovariectomized (OVX) rats. Intracerebroventricular (icv) administration of 2 nmol ANP or BNP decreased mean plasma LH concentration and LH pulse amplitude (P less than 0.05 for ANP; P less than 0.01 for BNP; n = 8/group) and frequency (P less than 0.01 for ANP and BNP). LH secretion was not affected by ANP or BNP at a lower concentration (0.2 nmol, icv; P greater than 0.05; n = 8/group). It was concluded that ANP and BNP may be involved in central regulation of LH secretion. Mechanisms possibly involved in suppression of LH secretion by ANP and BNP were also examined. OVX rats were treated with an opioid antagonist, naloxone (0.5 mg, iv), 45, 75, and 105 min after ANP or BNP (2 nmol, icv). Naloxone eliminated suppression of mean plasma LH concentration and LH pulse amplitude by 2 nmol ANP and BNP (P less than 0.05; n = 7/group). OVX rats were treated with a dopamine antagonist, pimozide (0.6 mg/kg, sc), 90 min before treatment with ANP or BNP (2 nmol, icv). Pimozide pretreatment blocked suppression of LH secretion by ANP or BNP (P less than 0.05; n = 9/group). Naloxone alone did not affect LH secretion (P greater than 0.05; n = 5). It was concluded that components of ANP and BNP suppression of LH secretion may depend upon opioid and dopamine activity.

[Effects of semen Ziziphis Spinosae oil and Ziziphis Spinosae extract on the decrease of serum lipoprotein and inhibiton of platelet aggregation]

Our experiments have shown that oral administration of Semen Ziziphis Spinosae oil(SZSO) or Ziziphis Spinosae extract (ZSE) given to quails for 53 days can significantly reduce their TC, LDL and TG and markedly subdue the fatty degeneration in their livers. Also, SZSO pressed into the stomach of rats for five days can conspicuously inhibit their platelet aggregation, while ZSE cannot.

Venous gas emboli and complement activation after deep repetitive air diving

Complement activity has been linked to decompression sickness (DCS), but the effects of intravascular bubbles on complement activation are poorly understood. We have investigated intravascular complement activation by measuring red blood cell (RBC)-bound C3d after repetitive air diving in man. Subjects were exposed to a single, 20 min, 170 fsw (feet of sea water) dive, or to 2 such dives with a 6-h surface interval. Doppler monitoring for venous gas emboli was performed postdive. Predive blood samples were studied to determine sensitivity of complement to activation by air bubbles. Other predive and postdive venous samples were evaluated for intravascular complement activation. No cases of DCS occurred in 39 dives. Baseline complement sensitivity appeared normally distributed, thus "sensitive" and "insensitive" subjects were not clearly distinguishable. RBC-bound C3d did not increase after 1 dive but did increase after the repetitive dive (P less than 0.05). Furthermore, maximum bubble grade was independent of complement activation.

[Pigmentary glaucoma and capsular glaucoma--a clinical and histopathological report]

In this paper, 7 cases (13 eyes) of pigmentary glaucoma and 9 cases (12 eyes) of capsular glaucoma were reported. Pigmentary dispersion in pigmentary glaucoma, pseudo-exfoliation material deposition in capsular glaucoma were the classical characteristics in the anterior segment of the eye, but pigmentary scatter was another clinical feature of capsular glaucoma. The histopathological studies of the trabeculectomy specimens by the light and transmission electron microscopy demonstrated that pigment granules or/and pseudo-exfoliation materials played an important role in obstructing the outflow tract of aqueous humor. In addition, we also discuss the diagnosis and differential diagnosis of both types of glaucoma.

Receptor selectivity of cholecystokinin effects on mesoaccumbens dopamine neurons

Extracellular recording techniques were combined with antidromic stimulation to examine the effects of C-terminal cholecystokinin (CCK) fragments and CCK antagonists on the activity of identified mesoaccumbens dopamine (MADA) neurons in chloral hydrate-anesthetized rats. These experiments were designed to determine the receptor selectivity of sulfated CCK octapeptide (CCK-8S) effects on MADA cells. Neither CCK tetrapeptide (CCK-4) nor unsulfated CCK octapeptide (CCK-8U) significantly altered MADA cell basal firing rate or responsiveness to the inhibitory effects of the D2 DA agonist quinpirole. As reported previously for ventral tegmental area DA cells, CCK-8S produced increases or decreases in the firing rate of most MADA cells sampled. CCK-8S also enhanced the sensitivity of MADA neurons to quinpirole-induced inhibition. This increase in sensitivity to quinpirole was blocked by pretreatment with the nonselective CCK receptor antagonist proglumide and the preferential CCK-A receptor antagonist CR 1409 but not by the preferential CCK-B receptor antagonist L-365,260. The inactivity of CCK-4 and CCK-8U in these tests and the results with the antagonists suggest that the effects of CCK-8S on MADA neuronal activity are mediated by CCK-A receptors.

Multiple functional enhancer motifs of rat ribosomal gene

Previous studies from this laboratory have characterized a 174 bp enhancer element which is located 2 kb upstream of the initiation site. Half of the enhancer action is controlled by a 37 bp element at the 3' end of the 174 bp region. We now report that a 43 bp adjacent domain which is located upstream of the 37 bp element constitutes an additional motif of the rDNA enhancer. When the plasmid consisting of the 43 bp DNA upstream of the rDNA core promoter was transcribed in a fractionated rat tumor cell extract (fraction DE-B), transcription of rDNA was augmented 4 fold. Electrphoretic mobility shift and DNAase I footprinting analyses showed that the purified 37 bp enhancer (E1)-binding protein, (E1BF) not only interacted with the enhancer motif E1 but also interacted with the neighbouring 43 bp enhancer domain E2. The specificity of the binding was demonstrated by competition with unlabelled 37 bp and 43 bp fragment and lack of competition with nonspecific DNAs in the mobility shift assay. These studies have shown that a single pol I transcription factor can bind to multiple enhancer domains with no significant sequence homologies and such multiple interactions may result in maximal transcription of ribosomal gene from the core promoter.

Effect of ginsenopolypeptide on the 3H-TdR integration of human blood lymphocyte

This paper reports the study of the effect of ginsenopolypeptide on 3H-TdR integration in normal human blood lymphocytes in vitro with micro-blood culture method of 3H-TdR integration. The results showed that the effect of ginsenopolypeptide on 3H-TdR integration in normal human peripheral blood lymphocytes which can be activated by phytoagglutinin was enhanced at low dosage and inhibited at high dosage, and its stimulating spike was 10(-6) micrograms/ml (P less than 0.01).

[Histo- and ultrahisto-pathology of the anterior chamber angle in congenital glaucoma]

92 trabeculectomy specimens of congenital glaucoma, aged 35 days to 46 years, were studied by light and transmission electron microscopy, with findings of narrowed anterior chamber angle, thickened ciliary muscle displaced forward, and crooked or thickened trabeculae, many disintegrated with hyaloid degeneration. The cribriform meshwork appeared dense, with deposition of fibrillae and collagen or basement membrane-like material; Schlemm's canal was absent in 3 specimens; in some the lumen was narrowed or locally obliterated; and Descemet membrane-like substance covered the trabecular meshwork. The types of pathological changes, their relationship with the symptoms, and the locations of outflow resistance were discussed.

Functional characterization of RNA-dependent DNA polymerase and RNase H activities of a recombinant HIV reverse transcriptase

The DNA polymerase and RNase H activities of HIV reverse transcriptase are both essential for HIV replication. Although the two activities are both catalyzed by a single polypeptide, they are physically separate; i.e., the DNA polymerase resides in the N-terminal domain whereas the RNase H is localized in the C-terminal domain. The present study was undertaken to characterize the enzymatic properties of these two activities and to determine whether the two catalytic sites are also functionally distinct. We have observed that EGTA specifically stimulates, whereas CaCl2 selectively inhibits, the RNA-dependent DNA polymerase activity but that neither compound has any effect on the RNase H activity of a recombinant HIV reverse transcriptase. The stimulation of the DNA polymerase activity by EGTA is dependent on the Mg2+ concentration; the greatest stimulation is observed at low Mg2+ concentrations. Similarly, the inhibition of DNA polymerase activity by Ca2+ is influenced by Mg2+ concentration. Ca2+ inhibition can be reversed by increasing Mg2+ concentrations, suggesting the possibility that CaCl2 inhibits the reverse transcriptase activity by competing for a metal-binding site on the enzyme. The pyrophosphate analogue phosphonoformate selectively inhibits the polymerase activity but not the RNase H activity of HIV reverse transcriptase. In contrast, the RNase H activity can be selectively inhibited by deoxyadenosine 5'-monophosphate, whereas the DNA polymerase activity is not inhibited. These results suggest that the DNA polymerase and RNase activities are not only physically separate but that they are also functionally distinct.

[Germination temperature of seeds of medicinal plants]

According to our experiments in the last ten years, the germination behaviour of the seeds of medicinal plants may be classified into five types by different temperature requirements for germination: (1) low temperature type; (2) middle temperature type; (3) high temperature type; (4) alternating temperature type; (5) wide ranging temperature type. This classification is helpful for cultivators to determine the time of sowing.

A modified electrode plate for low energy electric conversion of atrial fibrillation

Fifty-six patients with atrial fibrillation associated with heart disease were treated with a modified electrode plate for low energy electric conversion. Fifty-four (96%) of these cases were successfully converted into sinus rhythm using the modified electrode plates, a new site and low energy discharge (an average of about 50 J). To construct the new-style electrode plates, a 2 cm arc segment was cut from each of two electrodes (10 cm in diameter each). As for the site of application, the cut-edge of the anterior chest electrode, which has a concave diameter of 150 cm, is placed close to the right of the sterum over the fourth to sixth intercostal spaces, and the cut-edge of the other electrode is placed to the left of the spinal column at the level of the seventh to ninth thoracic vertebrae. The safe-effective period for the appearance of the first post-discharge QRS complex was found to be 1.4-5.0 s.

Effects of the CCK-A receptor antagonist CR 1409 on the activity of rat midbrain dopamine neurons

Previous studies have shown that acute intravenous treatment with sulfated cholecystokinin octapeptide (CCK-8S) but not unsulfated CCK-8 increases the number of spontaneously active midbrain dopamine (DA) neurons. This suggested that a peripheral-type (CCK-A) CCK receptor mediates this effect. Proglumide does not discriminate between CCK-A and CCK-B (central-type) receptors. In the present study, rats were treated acutely or repeatedly (14 days) with the selective CCK-A antagonist CR 1409. Repeated treatment with 5 mg/kg (IP) increased the number of spontaneously active DA cells in the A10 (ventral tegmental area) but not the A9 (substantia nigra zona compacta) region, which suggests that these DA populations are differentially affected by prolonged CCK-A receptor blockade. The sensitivity of impulse-regulating DA autoreceptors to the DA agonist quinpirole was not altered by CR 1409.

Evaluation of the effect of butyl p-hydroxybenzoate on the proteolytic activity and membrane function of human spermatozoa

The inhibition of the proteolytic activity of acrosin in human spermatozoa by butyl p-hydroxybenzoate was assessed by the gelatin substrate film method. Compared with a typical acrosin inhibitor, TLCK, the inhibitory activity of butyl p-hydroxybenzoate to acrosin was much more effective (20 times) than that of TLCK, proving that butyl p-hydroxybenzoate was a potent acrosin inhibitor. The effect of butyl p-hydroxybenzoate on membrane function of human spermatozoa was evaluated using a sperm-tail hypoosmotic swelling test and supravital stain method. A good correlation (r = 0.92) was observed between the % spermatozoa with normal membrane function and the % live spermatozoa after treatment of the spermatozoa with butyl p-hydroxybenzoate for 1 min, indicating that the death of spermatozoa caused by butyl p-hydroxybenzoate is probably due to impairment of sperm membrane function. Both the inhibitory effect on acrosin and the adverse effect on membrane function suggest that butyl p-hydroxybenzoate could be developed as a new vaginal contraceptive.