ICI 181,037: a novel eukalemic diuretic with antiarrhythmic activity

ICI 181,037, the most active compound from a series of 1,1-diarylcarbin-1-ol-2 amines, was evaluated for diuretic and cardiovascular activity. In saline-loaded rats, the magnitude of water diuresis and saluresis produced by ICI 181,037 (10 mg/kg, p.o.) was equal to that of hydrochlorothiazide. Water diuresis and saluresis produced by ICI 181,037 were enhanced with SKF 525A, ampicillin or neomycin plus lincomycin, suggesting that ICI 181,037 is an active diuretic. In conscious dogs, the saluretic activity of ICI d-181,037 (5 mg/kg, p.o.) was about 80% of the corresponding hydrochlorothiazide value, whereas the l-isomer demonstrated only minimum saluretic activity. In both rats and dogs, the concurrent kaliuresis after ICI 181,037 or its enantiomers was minimal as compared to hydrochlorothiazide. Following chronic dosing with diuretic doses, the basal levels of plasma potassium in dogs were not altered. In amphibian in vitro models for mimicking mammalian nephron, ICI 181,037 and its enantiomers demonstrated antinatriferic and antichloriferic activities, suggesting multiple renal sites of action for this agent. Racemic ICI 181,037 and its isomers reversed ouabain-induced arrhythmia in dogs and/or reduced the ouabain-induced mortality in mice after intravenous administration. It is concluded that ICI 181,037, particularly its d-isomer, is a novel eukalemic diuretic and possesses antiarrhythmic activity.

Persistent ethanol drinking increases liver injury induced by trinitrotoluene exposure: an in-plant case-control study

On the basis of a general survey conducted in a munitions plant, a case-control study was made on the various risk factors of liver damage induced by trinitrotoluene (TNT) exposure in the plant. One-hundred male cases with occupational TNT liver damage were paired with 100 male controls, one-by-one, for occupation, age and duration (years) of employment. A total of 55 possible risk factors were statistically analysed with a single factor analysis. On the basis of the single analysis, nine factors including drinking, smoking and education were further analysed with a conditional logistic regression model. A calculation was made on the odds ratio (OR) of each factor selected into the model. According to the estimated parameter of the established logistic model, the relative risk of the risk factors could be worked out. Finally, two factors, the amount of ethanol drunk on each occasion and the frequency of drinking every week were selected into the model at the level of a = 0.05. The result showed that these two factors have a dose-response relationship with their OR of occupational TNT liver damage, but there is no connection between smoking and occupational TNT liver damage and no interaction between drinking and smoking. The above results have revealed that people exposed to TNT and with a long history of heavy drinking, have a greater risk of suffering from chronic liver impairment than those that do not drink.

Electrochemical identification of dopachrome isomerase in Drosophila melanogaster

A principal reaction in the eumelanin biosynthetic pathway is the conversion of dopachrome (DC) to dihydroxyindole(s). Dopachrome isomerase (DI), the enzyme that catalyzes this reaction, was detected for the first time in larvae of D. melanogaster. Unlike the enzyme from B16 mouse melanoma cells which converts dopachrome to 5,6-dihydroxyindole-2-carboxylic acid (DHICA), the insect enzyme forms 5,6-dihydroxyindole (DHI). The activity of the insect DI was linear through 15 min incubation, and the amount of DHI produced was proportional to the amount of enzyme that was incorporated into the reaction mixtures.

GABAB receptor stimulation by baclofen and taurine enhances excitatory amino acid induced phosphatidylinositol turnover in neonatal rat cerebellum

Excitatory amino acid stimulation of phosphatidylinositol (PI) hydrolysis has been associated with development of the CNS. Normally minimally ineffective in stimulating PI hydrolysis in the neonatal rat cerebellum, N-methyl-D-aspartate (NMDA) increased levels of PI hydrolysis 82.3 +/- 5.5% above basal values in the presence of 1 microM baclofen, a gamma-aminobutyric acidB (GABAB) receptor agonist. This effect was observed at day 7 but not in adult cerebellum. The effect of baclofen could be mimicked by low dose GABA and taurine, actions which were blocked by prior application of a specific GABAB antagonist. Therefore, the ability of NMDA to stimulate PI hydrolysis in neonatal cerebellar tissue may be regulated by the degree of GABAB receptor stimulation.

Comparison of immunisation rates in general practice and child health clinics

OBJECTIVE

To compare immunisation uptake rates in general practice surgeries and community child health clinics.

DESIGN

Cohort study using data from a computerised child health system.

SETTING

Four health districts of North East Thames Regional Health Authority.

SUBJECTS

3616 children born January to March 1990 and resident in the four districts at the end of January 1991.

MAIN OUTCOME MEASURES

Immunisation uptake rates at 10-12 months of age, age at immunisation, scheduling performance at the two locations, and odds ratios of outstanding immunisations.

RESULTS

80% of children registered at general practices had completed their third dose of pertussis immunisation compared with 68% of those at health clinics. Median ages at the third dose were 24 weeks and 29 weeks at the two locations respectively. Scheduling was more effective at general practice surgeries. Unscheduled immunisations were more likely to be given after the recommended age. Overall, children resident in rural and suburban areas had greater uptakes than those in inner cities. Odds ratios for not being fully immunised among children registered at health clinics were 1.4 times those among children immunised in general practice and 3.0 times greater among children resident in inner cities than among those in rural and suburban districts. Children who moved into a district, however, were no less likely to be fully immunised than children who were born there.

CONCLUSIONS

The immunisation uptake rate was better in general practices than in child health clinics in both inner city and rural and suburban areas. Uptake may be increased with additional support to enable general practitioners to undertake immunisations, especially in inner cities.

Metabolism of linolenic acid and docosahexaenoic acid in rat retinas and rod outer segments

Docosahexaenoic acid (22:6 omega 3) is uniquely enriched in photoreceptor outer segment phospholipids, comprising up to one-half of the fatty acids of phosphatidylethanolamine and phosphatidylserine. The current study was designed to investigate the incorporation of 22:6 omega 3 into outer segment phospholipids over 12 days and to determine whether the retina contained the enzymes necessary for elongation and desaturation of the major dietary precursor of 22:6 omega 3, the essential fatty acid linolenic acid (18:3 omega 3). Sprague-Dawley rats were injected intravitreally with [14C]22:6 omega 3 or [14C]18:3 omega 3 and kept in cyclic light (12 hr light/12 hr dark) for 2 hr to 12 days. Phospholipids from rod outer segments and the remaining retinal debris were separated by two-dimensional thin-layer chromatography. [14C]22:6 omega 3 radioactivity was initially highest in phosphatidylcholine and rapidly decreased from 45% of total phospholipid labeling at 2 hr to 26% by 1 and 3 days in ROS, while phosphatidylethanolamine labeling increased from 49 to 68% by 3 days and phosphatidylserine labeling increased from 3 to 14% over 12 days. Phenacyl derivatives of total fatty acids were separated by HPLC. A substantial conversion of [14C]18:3 to [14C]20:5, [14C]22:5 and [14C]22:6 was noted after 1 days, with increasing conversion to [14C]22:6 over the 12-day period. When only one eye was injected with [14C]18:3 omega 3, negligible radioactive fatty acids were detected in the contralateral eye from 1 to 12 days post-injection demonstrating that conversion of 18:3 to 22:6 occurred primarily within the injected eye. All enzymes for elongation and desaturation of 18:3 to 22:6 appear to be present in the eye. However, the conversion of 22:5 to 22:6 by delta-4 desaturase is evidently rate-limiting and may affect phospholipid replacement during photoreceptor outer segment renewal if this pathway proves to be essential for the supply of 22:6 during disk membrane formation.

The endoscopic approach to the lateral accessory sphenoid sinus

In summary, an interesting case of an accessory parasphenoid sinus mucocele in a 10-year-old girl is reported. By choosing an endoscopic approach, hearing and balance were preserved, and an external sinus or neurosurgical procedure avoided. The surgery was done on an outpatient basis, with minimal postoperative discomfort and no complications. The mucocele was adequately drained and there has been no recurrence over the following 12 months.

[Effects of Epimedium sagittatum Maxim. Polysaccharides on DNA synthesis of bone marrow cells of "yang deficiency" animal model caused by hydroxyurea]

A study was made on the effects of Epimedium sagittatum polysaccharides on DNA synthesis of bone marrow cells of "yang deficiency" animal model caused by hydroxyurea with methods of cell culture in vitro and determination of 3H-TdR incorporating DNA of bone marrow cells. The results showed that after the treatment with 100 micrograms of Epimedium sagittatum polysaccharides, the cell multiplication rate was increased by 72% and DNA synthesis rate increased by 68%, in 1 x 10(6) cells.

Effects of changes in gp120-CD4 binding affinity on human immunodeficiency virus type 1 envelope glycoprotein function and soluble CD4 sensitivity

Mutant gp120 glycoproteins exhibiting a range of affinities for CD4 were tested for ability to form syncytia and to complement an env-defective provirus for replication. Surprisingly, gp120 mutants that efficiently induced syncytia and/or complemented virus replication were identified that exhibited marked (up to 50-fold) reductions in CD4-binding ability. Temperature-dependent changes in gp120, which result in a seven- to ninefold increase in affinity for CD4, were shown not to be necessary for subsequent membrane fusion or virus entry events. Mutant glycoproteins demonstrating even relatively small decreases in CD4-binding ability exhibited reduced sensitivity to soluble CD4. The considerable range of CD4-binding affinities tolerated by replication-competent HIV-1 variants has important implications for antiviral strategies directed at the gp120-CD4 interaction.

[Evaluation of a logistic regression model in predicting the prognosis of Graves' disease treated by antithyroid drugs]

One hundred and twelve new cases of Graves' disease were treated by tapazole for 6 months and followed up for another 12 months. The initial dose was 30 mg/d. Clinical and biochemical euthyroidism was achieved within 1 to 3 months, then a maintenance was given until cessation of drugs at 6 months. One hundred and eleven cases completed the study. Remission and relapse were defined at the end of follow-up for 1 year according to the presence or absence of clinical manifestation of hyperthyroidism and the levels of T3 and T4. The results of the 12-month follow-up showed that 46 of 111 cases were in remission, and the remaining 65 cases suffered relapse. A logistic regression model with 4 variables was established, which included thyroid suppression rate and goitre size by palpation at the end of drug treatment, the level of T3 before therapy, and the patients' age. The model had 81.5% sensitivity, 84.8% specificity and 82.9% (92/111) accuracy in predicting the outcome of Graves' disease after withdrawal of drug for 1 year. The results were much better than any other univariate analysis in this study.

[Botanical survey and quality evaluation of Chinese drug shiwei (folium Pyrrosiae)]

This paper deals with a botanical survey and identification of the Chinese drug Shiwei (Folium Pyrrosiae) on the basis of three most widely used species included in the 1985 edition of Chinese Pharmacopoeia, six species used in some districts of China, and two adulterant species. Three active constituents in seven species of Folium Pyrrosiae (mangiferin, isomangiferin and chlorogenic acid) have been determined.

Promoter DNA contacts made by the vaccinia virus early transcription factor

Vaccinia virus RNA polymerase requires the heterodimeric protein, vaccinia early transcription factor (VETF), for transcription of early gene templates in vitro. We have analyzed the vaccinia growth factor promoter sequences interacting with VETF at the nucleotide level and provide evidence that the factor contacts the DNA at two separate sites. DNase I protection analysis showed that VETF was found to nucleotides -12 to -29 relative to the transcription initiation site, and also to nucleotides +8 to +10 downstream of the initiation site. The importance of both binding sites for stable complex formation was supported by methylation interference analysis. Using synthetic oligonucleotides encoding different parts of the vaccinia growth factor promoter, it was shown that nucleotides down-stream of the transcription initiation site are required for stable complex formation. Competition binding experiments demonstrated that only the upstream binding site contributes significantly to binding specificity. Binding to two separated DNA sequences results in a bend in the promoter DNA as demonstrated by electrophoretic mobility shift analysis of permuted DNA fragments. These findings suggest that VETF activates transcription by sequence specific binding and structural alteration of the promoter DNA helix.

[Quantitation of platelet-bound von Willebrand factor in normal subjects and patients with coronary heart disease]

By using anti-human von Willebrand factor (vWF) monoclonal antibody, SZ-29, and indirect immunofluorescent technique and spectrofluorophotometer, we have quantitated platelet-bound vWF in normal subjects and patients with coronary heart disease (CHD). The results demonstrated that the quantity of platelet-bound vWF in CHD patients was significantly higher than that in normal (P less than 0.01) and the percentage of naturally activated platelet in CHD patients was also significantly higher than that in normal subjects (P less than 0.01). This might be one of the causes of hypercoagulability in CHD patients.

Dispersion of repolarization induced by a nonuniform shock field

Dispersion of repolarization may contribute to arrhythmias. To determine whether an electrical field stimulus (S2) with a nonuniform potential gradient can induce a dispersion of repolarization, we applied 5 ms rectangular S2 that had a nonuniform or uniform potential gradient during the action potential (AP) of bathed frog ventricular strips. One group had a partitioned bath to produce a nonuniform S2 of 39 +/- 11 V/cm (mean +/- SD) in one half of the 1 x 6 mm strip (H) and 0.3 +/- 0.2 V/cm in the other half (L), and simultaneous intracellular AP recordings in H and L with glass microelectrodes positioned 1.4 +/- 0.4 mm apart. Another group had uniform S2 and an AP recorded near the center of the strip. S1 pacing at 0.5 Hz was performed at one end of the strip and conduction along the strip was monitored. In each experiment, the S2 trials had an S1-S2 interval of 300 ms so that S2 was given during an AP (shocked AP). In both H and L, nonuniform S2 produced cumulative shortening of paced APs and lengthening of each shock AP compared with the paced AP preceding it. Uniform S2 of 1 V/cm did not shorten the paced APs or lengthen the shocked APs indicating that the AP changes in L were not due to the small potential gradient in L. Before beginning nonuniform S2 trials, the AP duration determined at the maximum repolarization rate was 601 +/- 72 ms in H and 602 +/- 71 ms in L (P = ns). During 13-20 nonuniform S2 trials over a 60-80 minute period, paced APs were shortened to 490 +/- 51 ms in H and 515 +/- 39 ms in L while each shocked AP was lengthened, compared with the paced AP preceding it, to 636 +/- 40 ms in H and 561 +/- 21 ms in L (P less than 0.05). Therefore, paced APs after shocks repolarized 25 ms earlier in H than in L and shocked APs repolarized 75 ms later in H than in L. The results show that during the shortened AP in H, the AP in L is shortened, which is consistent with intracellular current from L to H during repolarization. During the prolonged AP in H, the AP in L is prolonged compared with the paced AP preceding it, consistent with intracellular current from H to L during repolarization. Thus, nonuniform shocks can induce a dispersion of repolarization and may induce cell-to-cell interactions during repolarization.

[A study using FRTL-5 cell for detecting thyroid stimulating antibody activity in serum in patients with Graves disease]

Using a strain of functioning rat thyroid cells (Fischer rat thyroid line-5, FRTL-5) as target cells and immunoglobin G sedimented from serum by polyethylene glycol (PEG), we studied thyroid stimulating antibody (TsAb) activity in serum of patients with Graves' disease. In a total of 92 cases, TsAb activity was detected in 92.59% (25/27) of the patients with untreated Graves' disease, 75.00% (9/12) of the patients with relapsing Graves' disease and 39.13% (18/46) of the patients with Graves' disease who were euthyroid while taking antithyroid drugs. TsAb activity was also detected in 42.86% (3/7) of the patients with ophthalmic Graves' disease and 12.50% (2/16) of the patients with Hashimoto's thyroiditis. The results showed that TsAb activity can be used as an immunologic index and is valuable in the diagnosis of Graves' disease. Remission and relapse of Graves' disease can be indicated or monitored with the measurement of TsAb activity.

[Electron microscopic study of mesothelial cells in the diaphragm peritoneum of human fetus using the freeze-fracture replica method]

Electron microscopy of mesothelial cells from the diaphragm peritoneum of human fetuses was conducted using the freeze-fracture replica method. The results were as follows: 1) Numerous vesicles were found in single or cluster forms. The latter type was often fused with large vacuoles and opened to the free surface of the cell as secretory granules. 2) On the fractured faces of plasma and nuclear membranes, different numbers of intramembraneous particles and exocytic pores were seen on the PF surface of the plasma membrane. The diameter of the exocytic pores averaged 43 nm, and their maximum number was 26/microns2. 3) Neighboring cells were conjoined by cytoplasmic processes which were seemed to form three-dimensional intertwinings. 4) The microvilli of the mesothelial cells were grouped into three morphological classes, i.e. fork-like microvilli, bulbous ending microvilli, and stick-like microvilli. In addition, the contrast between the present investigation and the results of fine section studies on the diaphragm peritoneum of human fetus is discussed.

Detection of human papilloma virus (HPV) in laryngeal carcinoma tissue

Using alpha-32P-dCTP labelled human papillomavirus type 16 DNA genome probe (cHPV 16 DNA, cloned and identified from a Chinese cervical invasive carcinoma), 3 HPV 16 genomic relative sequences were detected in 6 biopsies of laryngeal carcinoma. The results showed serious HPV infection in laryngeal carcinoma. This indicates that HPV infection may play an important pathogenetic role in cancer development.

Temperature dependence of optical constants of MoS(2) for pyrooptical devices

The temperature sensitivity of the reflectance of MoS(2) under small temperature modulations has been investigated.It is feasible to detect temperature changes of 10(-2) degrees C by monitoring the reflectance, and thus MoS(2) is a potential candidate material for the pyrooptical sensors.

[Persistent ethanol drinking increases liver injury induced by trinitrotoluene exposure: an in-plant case-control study]

On the basis of a general survey conducted in a munitions plant, a case-control study was made on the various risk factors of liver damage induced by trinitrotoluene (TNT) exposure in the plant. The result of analysis showed that two factors the amount of ethanol drunk on each occasion and the frequency of drinking every week had a dose response relationship with their OR of occupational TNT Liver damage, but there was no connection between smoking and occupational TNT liver damage and no interaction between drinking and smoking on occupational TNT liver damage. The above results have revealed that exposure to TNT and with a long history of heavy drinking, have a greater risk of suffering from chronic liver impairment than non-drinking TNT exposure workers.

Plasmodium berghei: quantitation of in vitro effects of antimalarial drugs on exoerythrocytic development by a ribosomal RNA probe

A stage-specific ribosomal RNA probe has been used to quantitate exoerythrocytic development of Plasmodium berghei in primary cultures of mouse hepatocytes. Parasite rRNA could be detected as soon as 6 hr after sporozoite invasion and was increased during schizogony to a maximum at 48 hr, when mature schizonts were identified by microscopy. As few as 10 exoerythrocytic schizonts could be detected by filter blot hybridization, followed by autoradiography and liquid scintillation counting. By hybridizing the culture rRNA samples with either parasite-specific or universal rRNA probes, the in vitro tissue schizonticidal activity and hepatotoxicity of primaquine, two of its analogues, and pyrimethamine, could be assessed. After a 48-hr exposure of the culture to serial dilutions of each drug, a quantitative relationship was demonstrated between the decrease of the parasite rRNA and the increase of the drug concentrations. No significant parasite-specific rRNA could be detected at the concentration achieving complete inhibition of schizont formation but causing no cytotoxic effects on host hepatocytes. In contrast to microscopic-based assays, this molecular approach provides an objective and quantitative in vitro method for rapid screening and evaluation of tissue schizonticidal antimalarials.

Evaluation of the mechanical properties of hot isostatically pressed titania and titania-calcium phosphate composites

A number of composites based on titania and calcium phosphates, hydroxyapatite, bone ash or beta-tricalcium phosphate, were sintered by glass-encapsulated hot isostatic pressing at 925 degrees C. The mechanical properties of the titania and titania-calcium phosphate composites--three-point bending strength, fracture toughness and Young's modulus--were 250-450 MPa, 2.5-2.9 MPa m1/2 and 230-270 GPa, respectively. Hardness and density were also measured. The results suggest that these composites have potential applications in medicine as implant materials.