Preconditioning of isolated rat heart is mediated by protein kinase C

Catecholamines have been implicated in the phenomenon of ischemic preconditioning. We have previously demonstrated that ischemic preconditioning against postischemic mechanical dysfunction in the isolated rat heart is mediated by the alpha 1-adrenergic receptor. The purpose of this study was to delineate the signal transduction of preconditioning distal to the alpha 1-adrenergic receptor. Our results suggest that (1) transient ischemia and alpha 1-adrenergic receptor-induced preconditioning is inhibited by protein kinase C (PKC) antagonists, (2) functional protection against global ischemia/reperfusion injury can be induced by infusion of diacylglycerol, the second messenger of the alpha 1-adrenergic pathway, and (3) transient ischemia and alpha 1-adrenergic preconditioning are both characterized by similar translocation of PKC-delta to the sarcolemma of myocardium. These findings suggest that PKC is an effector of preconditioning in the isolated rat heart.

Clinical assessment of biplanar transesophageal echocardiography--a report of 125 cases

One hundred and twenty-five patients with cardiovascular disease were examined by biplanar transesophageal echocardiography (BTEE), including 67 with rheumatic heart disease (7 monitored during operation), 22 with aortic diseases, 20 with congenital heart diseases, and 16 with other kinds of heart disease. The results showed that BTEE was not influenced by corpulent and pulmonary emphysema and was better than transthoracic echocardiography at imaging the interatrial septum, left atrium and left atrial appendage, thoracic aorta, and mitral artificial valve and at intraoperative monitoring. BTEE was also better than single-plane transesophageal echocardiography, because BTEE could be used to observe the heart and thoracic aorta in transverse and longitudinal planes, thus enlarging the transmission "window" as well as allowing the entire lesion to be imaged. This study suggests that BTEE will have good prospects in clinical application.

Optimal batch size for estimation of the prevalence of a disease using combined samples

Great attention has been given to the combined sample test for its high efficiency. Here a model of mathematical expectation for combined samples has been worked out and used for investigating the prevalence of HCV in serum from blood donors. It was shown that this model was valuable if the probability of a positive test, e.g. the prevalence, is less than 0.31.

Redox mechanism for the chaperone activity of heat shock proteins HSPs 60, 70 and 90 as suggested by hydrophobic cluster analysis: hypothesis

We have recently shown that the N-terminal ATPase fragment of hsp70 (1-375, composed of domains I and II) as well as the subsequent domain III (376-520) may share three-dimensional similarities with hsp60. In this study, we propose that domain III, common to the hsp60s and hsp70s is also found in the hsp90s and adopts a beta-alpha-beta Rossmann-folded structure which is encountered in the NAD-binding domain of dehydrogenases. Consequently, with the help of the domain IV (in hsp70s and hsp90s) or of hsp10/GroES (in hsp60s) and possibly that of auxilliary partners, the hsp molecules could act as "unfoldases" or "reset systems" by disrupting secondary structures through redox reactions on the main polypeptidic chain with which they interact. The models built on this hypothesis may open up a new way for understanding the chaperone functions within the folding/unfolding processes.

Mechanisms of coronary vasomotor dysfunction in the transplanted heart

The transplanted heart sustains both cold ischemic and reperfusion injuries. These can produce coronary vascular endothelial or smooth muscle injury or both, which, in turn, can produce coronary vasomotor dysfunction. Using a canine model of autologous heart transplantation, we examined the following coronary vasomotor control mechanisms in isolated coronary artery rings: (1) endothelial-dependent cyclic guanosine monophosphate (cGMP)-mediated vasorelaxation (response to acetylcholine); (2) endothelial-independent cGMP-mediated vasorelaxation (response to sodium nitroprusside); and (3) beta-adrenergic cyclic adenosine monophosphate (cAMP)-mediated vasorelaxation (response to isoproterenol hydrochloride). Further, these mechanisms were related to 3 hours of cold ischemia alone and to 3 hours of cold ischemia plus 1 hour of reperfusion. Autologous heart transplantation was performed in dogs, and isolated distal left anterior descending coronary artery rings were studied in individual organ chambers. Cold ischemia alone produced significant dysfunction of beta-adrenergic cAMP-mediated vasorelaxation, which was exacerbated after reperfusion. Neither endothelial-dependent nor endothelial-independent cGMP-mediated vasorelaxation was dysfunctional after cold ischemia alone, but both were significantly impaired after reperfusion. We conclude that cold ischemia and reperfusion each produce coronary vasomotor dysfunction in the transplanted heart. Cumulatively, such coronary vasomotor dysfunction can acutely impair coronary vasodilatation and potentially jeopardize myocardial blood flow in the transplanted heart.

Improved microplate fluorometer counting of viable tumor and normal cells

An improved method has been developed to count cells in situ based on the measurement of esterase activity with carboxyfluorescein diacetate. This sensitive, semiautomated microplate fluorometer assay was able to estimate viable cell numbers over a range of 5 x 10(2) to 2.6 x 10(5) cells/well in a tumor cell line. Sensitivity to 10(3) was demonstrated in two other cell lines. Sub- and supranormal fluorescence events which can be responsible for unreliable readings when using a fluorescence assay for cell counting were quantified in a menadione (cytotoxic agent)/U-87 MG (cell line) model. There was a close correlation between the fluorometer method and Coulter counter method for two different tumor cell lines when this method was performed on cells after sub- and supranormal fluorescence events had ceased.

An improved HPLC assay for ciprofloxacin in biological samples

A simple and sensitive high performance liquid chromatographic method was developed for determination of ciprofloxacin (Cip) in 0.1 ml of rabbit and human serum and CSF. Separation of Cip and pipemidic acid (internal standard) was achieved on Nucleosil C18 (4.6 mm x 250 mm) using fluorescence detection with lambda exc 274 nm and lambda emi 418 nm. The mobile phase was composed of acetonitrile and phosphate buffer 10 mmol.L-1 (pH 2.7) containing tetrabutylammonium hydrogen sulfate 5 mmol.L-1 (18:82, vol:vol) and the flow rate was set at 1.0 ml.min-1. The retention times were 5.9 min for Cip and 4.0 min for pipemidic acid. The inter-day coefficient of variation was < 6.97% (n = 5) and the intra-day coefficient of variation was < 3.33% (n = 5). The limits of detection were 3 ng.ml-1 serum and 5 ng.ml-1 CSF, (r > or = 0.9996). Application of this method was demonstrated with simultaneous measurements of concentration-time profiles of Cip in rabbit serum and CSF during iv infusions at constant rates of 0.33, 1.0, and 2.5 mg.kg-1.h-1.

[The preliminary experiences of diagnosis and treatment for hypercalcemia crisis--clinical analysis of 23 cases]

This article report a study of 23 cases of hypercalcemia crisis resulting from primary hyperparathyroidism (18 cases), carcinoma (4 cases) and vitamin D intoxication (1 case). In addition to the symptoms of primary diseases, the patients with hypercalcemia crisis often had anorexia, nausea, vomiting, polydipsia, polyuria, psychoneurotic symptoms, arrhthmia. The severity of the symptoms was proportional to the degree of hypercalcimia. Serum calcium concentration of patients in hypercalcemia crisis should be equal or higher than 3.75 mmol/L (15 mg/dl) or serum ionized calcium higher than 1.88 mmol/L. Treatment hypercalcemia crisis consisted of rapidly lowering the serum calcium level by various measures while actively treating the primary diseases. Our experience is to supply normal saline intravenously or orally to increase the extracellular fluid and to enhance excretion of the urine calcium by administrating furosemide. In this paper, serum calcium concentration of 5 patients with hypercalcemia crisis treated with salmen calcitonin was reduced in varying degrees. The above mentioned treatment would be beneficial to the alleviation of the crisis and the preparation for operative treatment.

Loss of bactericidal activities of quinolones during the post-antibiotic effect induced by rifampicin

The post-antibiotic effect (PAE) is the phenomenon of persisting suppression of bacterial growth as a result of prior antimicrobial exposure. In antimicrobial therapy, multiple doses of either a single drug or a combination of drugs are common. Accordingly, the following question may arise: what impact might the PAE induced by the previous dose impose on the subsequent bactericidal action of a cycle-specific antibiotic. To answer the question, a study was conducted using pefloxacin, norfloxacin, ciprofloxacin and ofloxacin as test drugs, rifampicin as the PAE inducer and Escherichia coli ATCC 25922 as the test organism. Bacterial kill kinetics were determined for each quinolone at 4 x MIC before rifampicin treatment and during the PAE period following rifampicin challenge. The relative bactericidal activity of the quinolones during the PAE period was calculated. During the PAE period, pefloxacin, norfloxacin, ciprofloxacin and ofloxacin displayed only 6%, 8%, 7% and 33% of their normal activities, respectively. The results were compared to those obtained at low temperature (4 degrees C) and when the cells were challenged simultaneously with a quinolone and with rifampicin. The findings of this study suggest that prolonging the dosing interval by taking the PAE into account may not only lower the cost of antimicrobial therapy and the risk of toxicity, but also ensure the efficacy of subsequent doses.

[The diagnosis of primary hyperparathyroidism--analysis of 134 cases]

This article reports the diagnostic experiences of 134 cases of primary hyperparathyroidism (PHPT) confirmed by operation and pathologic examination. The clinical presentations were divided into 4 types: (1) 75 cases (56.0%) with bone resorption; (2) 47 cases (35.0%) with bone lesions plus urinary calculus; (3) 8 cases (6.0%) with urinary calculus only and; (4) 4 cases (3.0%) with hypercalcemia only. Bone lesions included bone resorption, osteomalacia and osteoporosis. Stones at multiple sites in the urinary tract or nephrocalcinosis were found in 41 cases. The measurement of ionized calcium was much more sensitive and accurate than the total calcium assay with the positive rate of 95.3% and 73.4% respectively. The concentration of plasma iPTH was high in the whole group (n = 84), the mean value was 21.4 +/- 17.9 times higher than that of the normal control group. For the localization of the affected parathyroid gland, instiat examination was by neck ultrasonography which gone a positive predictive value of 81.5% (43/53), 99mTc-MIBI scan showed positive rate 94.1% (16/17). The CT scan of the chest was used when ectopic location in mediastinum was highly suspected. If the first operative exploration failed to find the affected parathyroid gland, we performed the determinations of iPTH with samples taken from internal jugular vein through selective venous catheterization; the coincidence rate was found to be 85.2% (23/27).

[Experimental study on intratumoral injection with hydroxyapatite bioceramics and adriamycin in implanted hepatoma in mice]

Hydroxyapatite (HA) bioceramics is a biomaterial used in orthopedic area. We observed its anticancer effect in experimental hepatoma-22 (H22) in mice. BALB/c mice implanted with H22 were grouped into I, II, III and IV. Intratumoral injections were given as follows: (I) HA 0.1 g and ADM 0.1 mg n = 28; (II) HA 0.1 g n = 16; (III) ADM 0.1 mg n = 16; (IV) untreated n = 20. The tumor regression rates of the groups I, II and III were 65.9%, 41.9% and 51.1%, respectively. The mean survivals of groups I, II, III and IV were 32, 22, 26 and 18 days. Six mice of group I were alive more than 50 days before being killed, in which 4 tumor samples showed that no residual tumor cells could be seen under microscope. The possible mechanism of HA anti-cancer action is: (1) the dissolved matter of HA, glycoprotein and microfibril around the tumor cells may disturb the metabolism of cancer; (2) fibrocalcific process restricts the tumor growth; (3) immunoenhancement action (4) as a drug-release system HA is a hopeful agent of intratumoral injection for treatment of cancer.

Cloning of chicken hsp90 beta: the only vertebrate hsp90 insensitive to heat shock

The cloning of chicken hsp90 beta, reported here, supports the hypothesis that the hsp90 alpha and beta genes are the result of a gene duplication event that occurred at the time of the emergence of vertebrates. Avian hsp90 beta mRNA is not inducible by thermal stress contrary to the mouse and human hsp90 alpha and beta mRNAs. Moreover, hsp90 beta mRNA level is not increased by mitogenic stimuli, like serum or insulin, which induce hsp90 alpha mRNA. Different functions and regulations of hsp90 alpha and beta will be probably more easily understood in the avian species than in higher vertebrates.

[Pharmacological study on Veronicastrum sibiricum (L.) Pennell]

Six compounds were isolated from Veronicastrum sibiricum and identified as D-mannitol, beta-sitosterol, daucosterine, 3-0-acetyloleanolic acid, 3, 4-dimethoxy cinnamic acid and isoferulic acid. Pharmacological experiment has shown that isoferulic acid is anti-inflammatory and analgesic; 3-0-acetyloleanolic acid is anti-inflammatory; mannitol is analgesic, 3, 4-dimethoxy is also anti-inflammatory and analgesic.

[Pathological and clinical study on 80 cases of liver disease in pregnancy]

Ninety-seven cases of liver disease in pregnancy confirmed by pathological examination were studied. The results showed that in addition to virus hepatitis (58.8%), which was the leading cause, there were quite a proportion of other liver diseases. Among these acute fatty liver of pregnancy accounted for 18.6%, intrahepatic cholestasis of pregnancy were 16.5%. The causes of misdiagnosis and the bases for differential diagnosis were discussed. It was considered that early pathological examination of liver and other morphological study were important in diagnosis of liver diseases in pregnancy.

[Study on the serological typing of patients with epidemic hemorrhagic fever (EHF) and host animals in Junan County, Shangdong Province]

Using hemagglutination inhibition test (HI), we confirmed that Junan County is an endemic area of both EHF of R. norvegicus and A. agrarius, which indicated that the main host animals were R. norvegicus and A. agrarius in the area. Remarkable difference was shown between the infectious rates of pigs from the endemic area and that of pigs from the nonendemic area, which suggested that pigs could play certain roles in the transmission of EHF. We also proved that the main transmission mode of EHF virus in rats was horizontal transmission, and vertical transmission in rats also existed.

[Role of Langerhans' cells against cervical human papilloma virus infection and development of cervical carcinoma]

Human papilloma virus (HPV) in the development of cervicitis and cervical carcinoma, and the role of Langerhans' cells (LC) against cervical HPV infection and development of cervical carcinoma were studied by immunohistochemistry and by DNA molecular hybridization techniques for the HPV type 6, 11, 16 and 18 DNA sequences. The total results were analysed and correlated. It was found that the positive rate of HPV type 6 and 11 in cervicitis was significantly higher than that in cervical carcinoma (P less than 0.01), and the positive rate of HPV type 16 and 18 was higher than that in cervicitis, but only the difference of HPV type 16 positive rate reaches significance level (P less than 0.01). The results also showed that the mean density of S100 + LC in cervical carcinoma specimens was significantly higher than that in cervicitis specimens (P less than 0.01). The results indicate that HPV type 6 and 11 are closely related with cervicitis, and HPV type 16 and 18 are closely related with the development of cervical carcinoma. LC plays an important role in attacking HPV infection of the cervix and the development of cervical carcinoma. The results also suggest that S100 + LC and OKT6 + LC are different subtypes of LC, and S100 + LC is an activated-subtype which plays a major role of immunosurveillance function.

[Estrogen and progesterone receptors in laryngeal carcinoma]

The existence of hormone receptors on or within neoplastic tissue has potential diagnostic, therapeutic, and prognostic importance. It has now been demonstrated in many reports that cancers of the breast and prostate often express hormone receptors and can be controlled by hormone manipulation. The fact that larynx is a target organ for androgenic steroids has long been known. The question of whether laryngeal carcinoma expresses hormone receptors has been a matter of interest. We adopted the fluorescent hormone conjugate method to measure the estrogen receptor (ER) and progesterone receptor (PR) in 25 patients with laryngeal cancer. Our findings indicated that in 25 samples of laryngeal cancer 48% were ER positive, and 68% were PR positive. Cells of the laryngeal cancer not only contain ER and PR but also have relationship between the presence of receptors and the degree of histologic differentiation. Low differentiated cancers are inclinable to contain low level receptors. From this initial survey it appears that the hormone receptors could play an important role in the cancer of larynx. The presence of receptors in some laryngeal carcinoma implicates that these tumors are possibly hormone sensitive.

[Determination of the active constituent in Veronicastrum sibiricum (L.) Pennell]

The anti-inflammatory and analgesic constituent isoferulic acid was quantitatively analyzed by means of TLC-SM. The content is 0.09%.

Quantification of in-vitro post-antibiotic effect based on the mean recovery-time. I: Theoretical perspectives and a practical procedure

An empirical description of the post-antibiotic effect has been previously proposed on the basis of the time required for the bacterial density to increase by one log10 following antimicrobial exposure. In this study, a set of theoretical perspectives are established and the post-antibiotic effect quantitatively defined based on the mean-recovery time. The mean recovery-time can be determined by measuring the area above the growth curve of a bacterial population following antimicrobial exposure. It can be shown that the previously proposed description of the post-antibiotic effect may be regarded as a special case of the definition based on the mean-recovery. Furthermore, a practical procedure is described for the quantitation of the post-antibiotic effect from a given set of data in the form of a growth curve.

Quantification of in-vitro post-antibiotic effect based on the mean recovery-time. II: A comparison of colony counting versus photometric methods for the determination of bacterial growth

In the preceding paper, a method for the quantification of the post-antibiotic effect (PAE) has been developed based upon the mean recovery-time of an antibiotic-treated bacterial population, showing that the mean recovery-time is determined by the area above a growth curve of the bacterial population. Such an area determination of PAE implies that this method is less likely to be influenced by the early portion of a growth curve and therefore less dependent on the ability of a technique to detect a minimum bacterial density (sensitivity limit). In this study, this implication is further demonstrated in theory and through experimentation. As a result, an approach to estimation of contribution of the early portion of a growth curve to the quantitation of PAE based on the mean recovery-time is derived. The PAE of ciprofloxacin on Escherichia coli ATCC 25922 was determined under different test conditions using colony count and optical density measurements for determining bacterial growth. Differences in durations of the PAE quantitated by the mean recovery-time from the colony count measured and optical density measured growth curves were not statistically significant (P greater than 0.05).

[Karyotype analysis on bulbus Lilii]

A karyotype analysis has been made of the chromosome of five original species of Lilium. Lanceleaf Lily is the allotriploid.