[The role of transmission electron microscopy played in diagnosis of knotty tumors]

Eight cases were reported in order to elucidate the important role of electron microscopy (EM) played in diagnosis of knotty tumors. The diagnosis of tumors made by light microscopy (LM) could be confirmed, corrected or eliminated with EM, and the types and histogenesis of tumors could be decided more accurately with EM than with LM. But EM has its inherent limitations, so it is emphasized that diagnosis made by EM must rest on solid basis of LM, and sometimes EM should be combined with other methods, such as histochemistry and immunohistochemistry.

Studies on antipeptic ulcer agents: the quantitative structure-activity relationship analysis of heterocyclic aldehyde N4-substituted phenyl (thio) semicarbazones

Forty-five condensation products of furan-, pyrrole- and N-methyl pyrrole-alpha-carboaldehyde with N4-3- or N4-4-substituted phenyl semicarbazones and thiosemicarbazones were designed to optimize the antiulcer activity of a previously derived lead structure, formula II. Quantitative structure-activity relationships revealed that among the series of semicarbazones, increasing hydrophobicity and the introduction of electron-donating groups into the phenyl ring raise the antiulcer activity. Generally, semicarbazones are more active than the corresponding thiosemicarbazones. The wide gulf between the activity and toxicity of two derivatives (Compounds III and IV) necessitates further investigation of their pharmacological effects.

Inhibition of anaphylaxis-evoked intestinal fluid secretion by the dual application of an H1 antagonist and cyclooxygenase inhibitor

The regulation of anaphylaxis-mediated fluid secretion by the small intestine was examined in rats immunized by infection with Trichinella spiralis and reinfected by intraduodenal injection with L1 larvae. Net fluid secretion, which was measured as the volume of fluid present in the intestine 30 minutes after the challenge infection, was significantly greater in both actively and passively immunized rats than in nonimmune rats. The amount of fluid recovered from the immune host was equivalent to that secreted in response to 50 micrograms/kg of prostaglandin E2 or 250 micrograms/kg of cholera toxin. Worm-induced fluid secretion in immune hosts was reduced by treatment with diphenhydramine and inhibited by the dual application of diphenhydramine and indomethacin. Indomethacin alone had no effect despite inhibiting mucosal prostaglandin synthesis. Fluid secretion was unaltered by prior treatment of immune rats with a 5-lipoxygenase inhibitor, L-651,392, and only slightly reduced when L-651,392 was used in combination with indomethacin. After a challenge infection, more histamine was released into intestinal loops of immune rats than those of nonimmune rats. Prechallenge treatment of immune rats with indomethacin caused a twofold increase in histamine release. In summary, anaphylaxis-induced fluid secretion in the small intestine is mediated largely by histamine and cyclooxygenase products. This secretion can be lowered by treatment with diphenhydramine and further reduced by diphenhydramine in combination with indomethacin. The paradoxical effects of indomethacin when used alone and in combination with diphenhydramine are explained by the downregulation of histamine release by products of the cyclooxygenase pathway.

[New approach for management of retinal detachment with macular hole]

Three kinds of unconventional methods were used to treat retinal detachment with macular hole in 17 cases (17 eyes). A combination of vitrectomy, transscleral drainage and intraocular air injection was used for the cases of retinal detachment with macular hole and evident vitreous traction. Transscleral drainage combined with air injection was used for those of macular hole without vitreous traction. For the cases of combined peripheral and macular holes, we treated only peripheral holes, ignoring the macular hole. After a 3-16 months follow-up, 15 out of the 17 eyes obtained retinal anatomic reattachment (88.2%), 10 eyes had their vision improved, 4 eyes remained unchanged, 9 eyes obtained a visual acuity of better than 0.05 postoperatively. Compared with the conventional method of macular buckling, these procedures have the advantages of less damage to macula, less complications and more satisfactory visual improvement.

[Species differences in subacute toxicity of pyrrole aldehyde N4-(4-methoxyphenyl) semicarbazone]

The subacute toxicity of compound 1 was investigated in rats and dogs. Compound 1 was administered orally to rats of both sexes at daily doses of 0.5, 1.0 or 2.5 g/kg for 3 months. No change attributable to the administration of compound 1 was found either in blood count or in histopathological examination. Decreases in SGPT, alkaline phosphatase and lactic acid dehydrogenase and an increase in serum cholesterol were detected. Compound 1 was mixed with food and given to dogs of both sexes daily at doses of 0.2 or 0.5 g/kg for 3 months. Severe toxic symptoms including anorexia, emesis, ataxia and convulsive seizures were observed. A decrease in SGPT and increase in alkaline phosphatase were also detected. Hyperemia of the duodenal mucosa and severe kidney lesions were found in histopathological examination. Neither abnormality of appearance nor histopathological change was found in a pig receiving compound 1 at the daily dose of 0.1 g/kg for 3 months. The results suggest that there are differences of compound 1 metabolism among the species used in this study.

[Safety observation of attenuated live hepatitis B vaccine (H2 strain) in humans]

3089 healthy persons, aged 4 to 27 years, have been inoculated in 3 batches with attenuated live hepatitis A vaccine (H2 strain) since May, 1987. Each subject received 10(8.5) TCID dosage subcutaneously in the upper arm. None of the recipients developed any local or systemic reaction during a 42-day followup after vaccination. The serum enzyme activities, including SGPT/ALT and LDH5, were within normal range during the 4th to 16th weeks of serial tests after inoculation. The study of hepatitis A virus (HAV) shedding in feces of 4 subjects showed that no hepatitis A antigen (HAAg) was detected with antigen capture ELISA, but infectious HAV was recovered from stool-cell cultures in three of four recipients. No patient with hepatitis A was found within 6 months after vaccination in the institution where the HAV vaccine was used. In addition, no immunological evidence was seen that the HAV vaccine recipients can transmit HAV after the investigation of serological epidemiology at a class in which the HAV vaccine was tested. It is suggested that the potential of hepatitis A related to HAV vaccine among the non-vaccinated persons is rare. Seroconversion occurred at a mean time of 2 to 5 weeks after inoculation, and the positive rate of specific antibody was 95.6%.

Role of molecular diffusion in conventional and high frequency ventilation

The influence of molecular diffusion on gas-mixing during conventional mechanical ventilation (CMV) and high frequency ventilation (HFV) was studied by observing the wash-in of six poorly soluble, inert gases in arterial blood. Anesthetized dogs were ventilated either with CMV or HFV. Following a step change in inspired gas composition, the increase in arterial concentrations of hydrogen, helium, methane, ethane, isobutane, and sulfur hexafluoride was determined by gas chromatography. The relative gas diffusivities encompassed a range of almost one order of magnitude. Propane, present in inspired gas during both the control and wash-in phases, served as an internal reference for calculation of blood tracer concentrations. The wash-in of all six inert gases followed a single exponential time course during both CMV and HFV. The rate of wash-in of each gas decreased with increasing molecular weight (MW). The relationship of rate constants to a measure of relative diffusivity (MW-0.5) was significantly different than zero for both types of ventilation. The slope of this relationship was three times larger for CMV than HFV, indicating that molecular diffusion has a greater role in gas mixing during ventilation with large tidal volumes. Diffusion has a minor role in gas mixing during high frequency ventilation with small tidal volumes. Demonstration of the presence of gas separation secondary to molecular diffusion during HFV is enhanced by measuring wash-in, rather than wash-out, of inert gases because gas separation is likely to be obscured as exhaled gases pass through the well-mixed central airways during gas wash-out.

Control of src kinase activity by activators, inhibitors, and substrate chaperones

The activities of src tyrosine kinases are greatly influenced by substrate modulators (chaperones). In the presence of bovine serum albumin, the phosphorylation of a random polymer of glutamic acid, alanine, and tyrosine (1:1:1) by src kinases is stimulated 20- to 100-fold, but there is little stimulation with a polymer of glutamic acid and tyrosine (4:1) as substrate. This suggests that serum albumin interacts with the substrates rather than with the enzyme. groEL and several other heat shock proteins also stimulate the phosphorylation of a random polymer of glutamic acid, alanine, and tyrosine (1:1:1). In the absence of substrate modulators, the phosphorylation of calmodulin and of several ras proteins by src kinase is barely detectable. In the presence of polylysine or protamine, marked phosphorylation is observed. Another type of control of src kinase activities appears to be directed toward the enzyme rather than the substrate. Triton X-100 extracts of plasma membranes of bovine brain contain a heat-stable factor that stimulates c-src kinase activity with any of the polymers as substrate. The same extract contains a heat-labile factor that preferentially inhibits c-src kinase activity. The two factors are separated by DEAE-Sephacel and phosphocellulose chromatography. The presence of the activator enhances the potency of the inhibitor.

[Comparative study of Campylobacter pyloridis and Campylobacter jejuni under electron microscope]

Specimens were made by preparing the ultrathin sections after negative staining and ruthenium red staining. The specimens were observed under electron microscope. Results revealed that the shapes of Campylobacter pyloridis (Cp) and C. jejuni (Cj) were similar, but distinctive differences in their structures were observed. Cp had one to five sheathed flagella at one end with bulbous tips. Cj had only one unsheathed flagellum on each end without a bulbous tip. The cell body of Cp was longer than that of Cj. A layer of thick and dense delicate filament-like substance was attached to the surface of the cell body of Cp in the ultrathin sections with ruthenium red staining, in the case of Cj only a little of such a substance could be noted.

[Prenatal sex identification with biotinylated human Y-specific DNA probe]

Using biotinylated human Y-specific DNA probe PHY2.1 and Cos 84, we carried out Southern and dot hybridization with human DNA from artificially aborted chorionic villi, and with DNA of peripheral lymphocytes from normal male and female. The results show that PHY2.1 may be applied in prenatal sex identification both by Southern and by dot hybridization but with Cos 84, only Southern hybridization could be used.

The changes of BPA level in 31 cases of children with aplastic anaemia and its clinical significance

Burst-promoting activity (BPA) was measured in the sera from 31 children with aplastic anaemia (AA). BPA levels were elevated in most of the children with AA (65.2%), the mean value (137.7 +/- 18.4%) being significantly higher than that in normal children (69.6 +/- 9.4%), in children in the recovery period and in children with non-aplastic anaemia. There was a negative relationship between the BPA level in children with AA and the peripheral haemoglobin concentration. The BPA level was higher in those whose duration of illness was shorter than 1 year. In three cases of AA caused by chloramphenicol and benzene hexachloride and one case of congenital pure red cell AA, the BPA level was not elevated. Eleven patients received fetal liver cell suspensions intravenously (FLI). After FLI the BPA level in their sera was significantly reduced. According to these results, it appears that the elevation of BPA level is a special phenomenon of AA. The measurement of BPA in serum is helpful for differentiation between AA and other kinds of anaemia. The elevation of the BPA level in serum is a biological compensation for the haematopoietic disorder, and the measurement of BPA in the serum of patients with AA may be helpful in evaluating the haematopoietic condition.

[Purification and characterization of beta-N-acetyl hexosaminidase from Aspergillus tamarii]

A beta-N-acetylhexosaminidase from mycelium-free culture filtrate of Asp tamarii S215 was purified to PAGE homogenous by ammonium sulfate and polyethylene glycol fractionation precipitation followed by Sephadex G-50 desalt, DEAE-Sephadex A-25 chromatography, hydroxyapatite chromatography and DEAE-Sephadex A-25 rechromatography with 170-fold purification and 24.7% recovery. The ratio of the beta-GlcNAcase and beta-GalNAcase was 2.5 and remained constant throughout the purification. The Mr estimated with concentration gradient PAGE was 140,000 and subunit Mr determined with SDS-PAGE was 72,000, the number of subunit were 2. The pI was 4.2 determined by PAGIEF. The optimum pH was 5.5-6.5 and 5.0-6.0 for beta-GlcNAcase and beta-GalNAcase respectively with stable pH range 5.5-8.3 for both. The optimum temperature was 60 degrees C for beta-GlcNAcase and beta-GalNAcase. The residual activity of beta-GlcNAcase was 52.7% after treated at 50 degrees C for 8 h and it was 44.9% for beta-GalNAcase. The residual activities of both were down to 1% after treated at 62 degrees C for 10 min. The activity was slightly activated by Mn2+ or Fe2+, while strongly inhibited by Hg2+ and slightly by Ag+, Cu2+, Pb2+, Cd2+ or Zn2+. Analyses of amino acids composition showed that the beta-HexNAcase contained about 24.2% acidic amino acids and 14.9% basic amino acids and only 0.6% methionine.