Brain abscess due to Pasteurella multocida

The patient was a 26-year-old man who complained of headache and vomiting. On examination, there was nothing abnormal, but the edge of the right optic papilla was not clear. His temperature was 38.5 degrees C, pulse 96/min, blood pressure 120/80 mmHg. A space-occupying lesion in his fronto-dextra cupular part was found by CT scanning. He had a 12-year history of chronic purulent otitis. The diagnosis was a brain abscess in the fronto-dextra cupular part. The brain abscess was extracted and Pasteurella multocida was isolated from the dark brown pus draining from the abscess. The patient recovered through proper antibiotic therapy based on a sensitivity test. Reports of infections caused by this organism in foreign countries very widely from local infections due to bites and scratches by cats, dogs etc. to general infections such as infections of the respiratory tract, sepsis and meningitis. However, Pasteurella multocida brain abscesses are rare. Pasteurella multocida is a Gram-negative short rod which is best known as part of the mouth flora and as a pathogen causing septicemia in many domestic animals, such as cats, dogs etc.. Infection in man results mainly from animal bites or scratches. It has been reported that Pasteurella multodida can cause human septicemia, meningitis, respiratory tract infection, conjunctivitis and other infections. We isolated a strain of Pasteurella multocida from the pus of a brain abscess following chronic purulent otitis on August 6, 1990.

Importance of lysine and arginine residues to the biological activity of trichosanthin, a ribosome-inactivating protein from Trichosanthes kirilowii tubers

Lysine and arginine residues in trichosanthin were modified with ethyl acetimidate and phenylglyoxal, respectively. The effects of these chemical modifications on the cell-free protein-synthesis-inhibitory activity and the antigen-antibody (Ag-Ab) interaction between trichosanthin and its antibody were examined. Ethyl acetimidate modification abolished the protein-synthesis-inhibitory activity of trichosanthin. The inactivation process followed simple first-order kinetics with an inactivation half-life of about 18.5 min. Modification of one lysine residue seemed to be responsible for such inactivation. Arginine modification also inactivated trichosanthin. The inactivation process, however, was biphasic with inactivation half-lives of approximately 15 and 540 min. Arginine modification of trichosanthin had little or no effect on Ag-Ab interaction, whereas lysine modification slightly but significantly weakened Ag-Ab binding.

Enantioselective antiplatelet actions of nipecotamides

Two synthetic racemic nipecotamides, 1-decyl-3-(N,N- diethylcarbamoyl)piperidine hydrobromide (1) and alpha, alpha'-bis[3-(N-benzyl-N-methylcarbamoyl)piperidino]-p-xylene dihydrobromide (2) were resolved on a chiral alpha 1-acid glycoprotein semipreparative HPLC column. Thus, rac.1 was resolved into two enantiomers 1A-(+) and 1B-(-); rac.2 was separated into the optical antipodes 2A-(-) and 2C-(+), and the meso diastereomer 2B-(0). Also on a preparative scale, 97% pure 2C was obtained via diastereomeric salt formation using dibenzoyl-L-(-)-tartaric acid. The individual isomers were evaluated for their platelet aggregation inhibitory potency. In inhibiting ADP-induced aggregation of human platelets in vitro, 1B-(-) was 4 times more potent than its optical antipode 1A-(+), and 2C-(+) was 6 times as active as 2A-(-); the meso diastereomer 2B-(0) had intermediate activity. With collagen as the 1B-(-) was twice as active as 1A-(+), and 2C-(+), the most active compound in this series (IC50 = 0.96 microM), was 10 times more potent than its antipode 2A-(-). Again, the meso diastereomer 2B-(0) had intermediate activity. These results demonstrate the enantioselective antiplatelet actions of mono- and bis- nipecotamide derivatives.

Pfs2400 can mediate antibody-dependent malaria transmission inhibition and may be the Plasmodium falciparum 11.1 gene product

Monoclonal antibodies (mAb) have been raised against Plasmodium falciparum gametocyte stage protein extracts, in an effort to identify novel parasite antigens that might mediate malaria transmission-blocking immunity. mAb 1A1 identified Pfs2400, a sexual stage-specific antigen of greater than 2 megadaltons, that is associated with the outer leaflet of the parasitophorous vacuole membrane in mature circulating gametocyte-infected red blood cells. Upon induction of gametogenesis, Pfs2400 partitions between the gamete plasmalemma and the degenerating erythrocyte membrane. The antigen is no longer detectable in the fully emerged gamete. mAb 1A1 dramatically reduces the number of oocysts formed in P. falciparum gametocyte-fed mosquitoes. The cognate antigen is probably the product of the Pf11.1 gene (Scherf et al. 1988. EMBO [Eur. Mol. Biol. Organ.]J. 7:1129) on the basis that a peptide composed of two copies of the degenerate nine amino acid repeat sequence in the Pf11.1 protein, can inhibit binding of mAb1A1 to the native antigen. The mechanism of transmission inhibition mediated by the Pfs2400 is discussed.

Glycosylation and membrane insertion of newly synthesized rat dopamine beta-hydroxylase in a cell-free system without signal cleavage

Dopamine beta-hydroxylase (DBH, EC 1.14.17.1) is present in both membrane-bound and soluble forms in neurosecretory vesicles. This study was designed to investigate the differences between membrane-bound and soluble DBH and how they may arise from translation of a single mRNA. Antisera to a peptide corresponding to the carboxyl terminus of rat DBH was found to specifically immunoprecipitate the 77- and 73-kDa subunits of newly synthesized DBH in rat brain. Thus, both soluble and membrane-bound forms contain the same carboxyl terminus. To investigate differences at the amino terminus, full-length rat DBH mRNA, translated in a cell-free system, produced a 66-kDa peptide. An additional higher molecular mass product was synthesized upon co-translational addition of microsomal membranes. This product was glycosylated since it bound to concanavalin A-Sepharose and reverted to the 66-kDa polypeptide after treatment with endoglycosidase H. This glycosylated product was resistant to protease digestion and fractionated with microsomal membranes on sucrose gradients, indicating that it is incorporated into the microsomal membranes. Amino-terminal sequencing of the glycosylated translation product indicated that the amino-terminal "signal" sequence was not cleaved. The results indicate that in the cell-free system newly synthesized DBH undergoes glycosylation and incorporation into microsomal membranes without cleavage of the NH2-terminal signal sequence.

Chiral separation of nipecotic acid amides

1-Decyl-3-(N,N-diethylcarbamoyl)piperidine (1) and alpha,alpha'-bis[3-(N-benzyl-N-methylcarbamoyl)piperidinol]-p-xyle ne (2) represent mono-N-substituted and bis-N-substituted carbamoylpiperidines, or nipecotic acid amides, respectively. Initially, several attempts were made to resolve these compounds using beta-cyclodextrin, cellulose carbamate and Pirkle-type columns. However, the interactions of the stereoisomers of the two compounds with these stationary phases did not differ enough to permit satisfactory separations. Baseline resolution was achieved using an alpha 1-acid glycoprotein (AGP) chiral column. The mobile phase was phosphate buffer (pH 7.0). Tetrabutylammonium (TBA) was used as the cationic modifier and ethanol as the uncharged modifier. Circular dichroism was used to identify the enantiomers. Compound 1 was resolved into positive and negative enantiomers and 2 into positive and negative enantiomers and a meso diastereomer. The influence of pH, buffer ionic strength, cationic and uncharged modifier concentrations on retention, chiral selectivity and resolution were evaluated. Based on the results, it is suggested that both ionic and hydrophobic interactions may be responsible for retention and resolution.

Correlated binomial variates: properties of estimator of intraclass correlation and its effect on sample size calculation

In group randomized studies, the sample size calculations are complicated by within group (worksite, community, etc.) correlation. We compare by simulation the moment method and the more standard ANOVA method of estimating the intraclass correlation. We find the former is less biased for a small to moderate number of clusters but the difference disappears when the appropriate degree of freedom is used for the ANOVA estimator. We propose a simulation approach for sample size determination and illustrate it with an example.

Molecular determinants of the platelet aggregation inhibitory activity of carbamoylpiperidines

A series of alpha,alpha'-bis[3-(N,N-dialkylcarbamoyl)piperidino]-p- xylenes were synthesized and tested for their inhibitory activity on ADP-induced aggregation of human platelets. A parabolic curve was obtained when log 1/C (activity) was plotted against log P (octanol/water partition coefficient). Using this as a model, a new analogue, alpha,alpha'-bis-[3-(N-methyl-N-butylcarbamoyl)piperidino]-p-xylen e (3g), was synthesized with a predicted IC50 of 25 microM. When this compound was subsequently evaluated, the IC50 was 22.1 +/- 5.5 microM, demonstrating the applicability of this model. The amide oxygen of the carbamoyl substituent appeared necessary for activity. Thus, for example, when the amide carbonyl group of 3a (IC50 = 44.5 microM) was reduced to CH2, the resulting compound 4 had a dramatically reduced activity, IC50 = 1565 microM. Compound 3a was resolved into (+) and (-) enantiomers and a meso (0) diastereomer using fractional crystallization, diastereomeric tartrate formation, and chiral HPLC. Compared to (-)-3a, the (+) isomer was 15 times more potent when ADP was the agonist and 19 times more active when collagen was used as the agonist. Molecular modeling of R,R- and S,S-3a using the SYBYL program was used to examine their interactions with phosphatidylinositol (PI). There was a better fit between PI and the R,R-3a with the energy of interaction being 17.6 kcal/mol less than that of the S,S-3a/PI complex. Although the absolute stereochemistry of individual enantiomers is not known, this study shows that R,R-3a interacts more favorably with PI than does S,S-3a and that (+)-3a is a more potent inhibitor of human platelet aggregation than (-)-3a. It is postulated that because of their lipophilicity, these compounds penetrate the platelet membrane and are then protonated at the pH of the cytosol. The protonated N then neutralizes the anionic charge on the membrane phosphoinositides, thereby rendering them less susceptible to hydrolysis by phospholipase C. Thus, the determinant parameters for optimum antiplatelet activity in 3-carbamoylpiperidines are (1) the amide carbonyl, (2) appropriate stereochemistry of the 3-substituent and (3) a log P value of about 4.5.

[A research on near-death experiences of survivors in big earthquake of Tangshan, 1976]

81 survivors with Near-Death Experiences (NDEs) in a severe earthquake (Tangshan, 1976) were reviewed. Among them 40 NDE phenomena were found and strange bodily sensation, thought unusually vivid, loss of emotions, unusually bodily sensations, life seemed dream, feeling of being dead, feeling of peace or cuphoria, life review or "panoramic memory" and thinking unusually fast comprised more than half of the group. It seemed that our observation was somewhat different from that of pasricha (India) and Greyson. In our series, the survivors with more than 7 scores on Greyson's NDE scale account for 32 cases, and in whom, the cognitive and transcendental types comprise the great part. This findings suggest that the components, sequences and types of NDE might be correlated to races, regions, psychological and cultural backgrounds, and kinds of event.

Modulation of expression of delayed hypersensitivity by mycobacterial antigen 85 fibronectin-binding proteins

Although demonstration of delayed hypersensitivity to purified protein derivative of tuberculin (PPD) is an important element in the diagnosis of infection with Mycobacterium tuberculosis, many patients with tuberculosis are anergic. Several possible mechanisms for this specific lack of response have been described. We have now uncovered an additional one. T-cell fibronectin (FN), a lymphokine secreted by activated T cells, is closely associated with the initiation of delayed hypersensitivity reactions. Mycobacterial antigen 85 (Ag85) proteins have been shown to bind to plasma FN. The ability of Ag85 to bind to T-cell FN and modulate expression of delayed hypersensitivity was therefore studied. Purified Ag85 proteins from M. tuberculosis, Mycobacterium bovis BCG, or Mycobacterium kansasii bound to T-cell FN, fibroblast FN, and plasma FN in vitro. Purified 65-kDa heat shock protein (hsp65) from M. bovis BCG did not bind to any FN. Ag85, but not hsp65, inhibited the ability of T-cell FN to agglutinate monocytes in vitro in a dose-dependent manner. In vivo, mixtures of PPD or dinitrophenyl-ovalbumin and purified M. tuberculosis or M. bovis BCG Ag85 proteins elicited significantly smaller delayed hypersensitivity inflammatory reactions in sensitized guinea pigs than did PPD or dinitrophenyl-ovalbumin alone. Purified hsp65 did not inhibit expression of delayed hypersensitivity to PPD or dinitrophenyl-ovalbumin. We suggest that Ag85 proteins could inhibit in vivo expression of delayed hypersensitivity during mycobacterial infections because of their interaction with T-cell FN.

Risk factor patterns for coronary heart disease in China, Japan and Germany

The risk factor patterns for coronary heart disease in China, Japan and Germany were studied. 6,025 Germans, 7,580 Japanese and 2,047 Chinese aged 30-59 were investigated following the protocol of the Göttingen Risk, Incidence, and Prevalence Study carried out in West Germany in 1982. It is concluded that in China, the risk factor intervention focuses mainly on smoking and hypertension; smoking also remains the most important risk factor in Japan; while in Germany the major targets are obesity and hyperlipidemia. However, about 38% of the participants from West Germany showed 3 or more risk factors accumulated per person. Thus the multifactorial risk factor reduction might be necessary in Germany.

[Immunological identification of tiger-bone]

Anti-tiger sera were prepared by using tiger serum proteins to immunize the rabbits. Tiger-bone can be identified by the specific serological reaction between the anti-tiger sera and the tiger-bone proteins.

Differences in the risk factor patterns for coronary heart disease in China, Japan, and Germany

In Asia coronary heart disease mortality is almost 10 fold less frequent than in European countries. These findings attract interest to search for different risk factor patterns. From 1982 to 1985 epidemiologic surveys were carried out in China (n = 2047), Japan (n = 7580) and Germany (n = 6052). Healthy, male subjects, aged 30 to 59 years were enrolled. The prevalence rate of hypertension for the Germans was 20% versus 18% for the Japanese, and 11% for the Chinese. About 69% of Chinese, 55% of Japanese, and 37% of Germans were smokers. About 66% of the Germans were overweight (BMI greater than 25), 17% of the Japanese, and 11% of the Chinese. The highest risk group with cholesterol levels of greater than 300 mg/dl included no Chinese subject, 0.1% of the Japanese, but 5% of the Germans. The lipoprotein profiles among the Japanese and the Chinese collectives typically showed antiatherosclerotic characteristics, whereas most Germans exhibited profiles which support development of atherosclerosis. About 36% of the participants from Germany showed 3 or more risk factors accumulated per person (Japan and China 5%). Multifactorial risk factor reduction for Germany is recommended.

Incidence and mortality rates of myocardial infarction in Chinese workers aged 40-59 in relation to coronary risk factors. Results of a Chinese prospective study (Wuhan Study) in comparison to the Göttingen Risk Incidence and Prevalence Study (GRIPS)

Some 2045 male Chinese industrial workers aged 40-59 years living in the city of Wuhan in the People's Republic of China were examined for coronary risk factors in the year 1983. The investigation included a patient history, clinical examination, and ECG and laboratory tests, with special attention to serum lipids. After 5 years, a follow-up investigation of the study group was carried out. The results were compared to the similarly designed German GRIPS project. In comparison to the German population, significantly lower levels for total-, LDL-, and VLDL-cholesterol, apolipoprotein B, triglycerides, uric acid, body mass index, and diastolic blood pressure were found in China. The percentage of smokers, however, was remarkably higher in China than in the Federal Republic of Germany. During the 5 year observation period in the Chinese sample, four subjects suffered from sudden death and four from nonfatal myocardial infarction; in the German study group three times as many fatal myocardial infarction and cases of sudden death and 7.5 times as many nonfatal myocardial infarctions were recorded. Nonfatal coronary heart disease and peripheral vascular disease were also observed less often in China. The incidence of cerebrovascular diseases was 1.5 times higher in China than in Germany. Whereas in Germany, total-, and LDL-cholesterol values were the major distinguishing parameters between infarction and reference groups, in China these values have thus far had no significant influence on the level of risk. Instead in the Chinese incidence group, significantly higher levels for blood pressure, body mass index, uric acid, and the ratio LDL/HDL-cholesterol were found.