[Experimental analysis of the calcium source for cardiac excitation-contraction coupling in hibernator Citellus dauricus]

The force-interval and force-frequency relationships and the effects of Cd2+ and ryanodine on the myocardial action potential and contraction were compared between hibernating (HGS) and active (AGS) ground squirrels Citellus dauricus. (1) Raising the driving frequency caused a negative inotropic effect in the AGS group, but a biphasic change with an increase of the peak force followed by a decrease in the HGS group. The contraction in HGS group exhibited a more pronounced post-interval potentiation, and was more significantly modulated by the driving frequency. (2) HGS animals displaged action potentials of shorter early-stage duration and stronger contractions of shorter time course in comparison with the AGS animals. Both the action potential and the contraction of HGS group were less affected by Cd2+, but the contraction was more significantly inhibited by ryanodine than that of the AGS group. Our results suggested that dependence of cardiac excitation-contraction coupling on calcium influx was weakened, while the function of sarcoplasmic reticulum as a source of activator Ca2+ was enhanced during hibernation, which might take an important part in the cold-tolerant adaptation of hibernating hearts.

[Seasonal variation in the ultrastructure and calcium uptake rate of cardiac sarcoplasmic reticulum in ground sqirrel]

The ultrastructure and calcium uptake rate of the cardiac sarcoplasmic reticulum (SR) was quantatively compared between the ground squirrels (Citellus dauricus) in hibernating and non-hibernating season. (1) In our ultrastructural investigation, OsFeCN post-fixation method was used to enhance the staining of SR, which made the SR structure more recognizable. (2) The results of morphometrical analysis demonstrated that the volume density of SR and lipid droplet in the cardio-myocyte was significantly higher (P < 0.01) in the hibernating animal than in the summer active one, and the subcompartment of SR with this difference was non-junctional SR. (3) The cardiac SR from hibernating ground squirrels had a higher (P < 0.01) calcium uptake rate as measured by the absorbence of arsenazo-III Ca2+ indicator, than that from autumn active ones. Altogether, our results suggested that the function of SR in the uptake of cytosolic calcium was enhanced in hibernating season, which may play an important role in the cold tolerance of myocardium of a hibernator.

[Electron microscopic study on the petechial hemorrhagic spots in patients with epidemic hemorrhage fever (EHF)]

EHF viral particles were found in the squamous epithelial cells and capillary endothelial cells of the petechial spots located at the mucous membrane of the soft palate in cases of early stage of severe type EHF by transmission electron microscopy. The viral particles are round or oval in shape, about 100 nm in diameter with a lipid bilayer envelope from which spikes are protruding. The virions matured by budding through the intracytoplasmic membranes into the smooth surfaced vesicles. The morphological characteristics of the virion coincided with the viral particles of Family Bunyaviridae. It was the first time to demonstrate that the squamous epithelial cells of the soft palate is one of the target cells in EHF virus infection and to describe the subcellular morphological evidence of the petechial spots at the soft palate by EM.

Biochemical and morphological changes in the lenses of selenium and/or vitamin E deficient rats

The activities of glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) and free radicals were measured, and the morphological changes were observed in the lens of control rats, selenium-deficient (SeD) and/or vitamin E deficient (VED) rats. The activities of GSH-Px in the lens of SeD rats decreased significantly. The GSH-Px activities of lens were positively related to erythrocytes selenium level. There was a free radical at g = 2.0015 in the rat lens of all groups, but the content of free radicals in the lens of SeD group was significantly higher than that of the control group. The free radical content of lens was negatively related to erythrocytes selenium level, as well as the GSH-Px activities in the lens. In vitro, ultraviolet radiation caused the generation of another kind of free radical (g = 2.0097) in the lens of all groups, but the amount of the free radical in the lens of the SeD group was also significantly higher than that of the control group. The activities of SOD and GSSG-R in VED rat lens were significantly decreased. The amount of MDA in the lens of SeD and/or VED rats were significantly increased. The results showed that the decrease of antioxidative capability in the lenses of SeD and/or VED rats accelerated the lipid peroxidation and generation of free radicals. Although only early morphological changes in SeD and/or VED rat lens were observed, it is considered that selenium and vitamin E deficiency may be involved in the occurrence of cataract.

[Studies on the isolation of endogenous sleep factors from Tupaia Belangeri Chinensis (TBC) after sleep deprivation]

The present study was undertaken to explore endogenous sleep factors isolated from 48-72 h sleep deprived (SD) male Tupaia belangeri chinensis (TBC). Only drink ad libitum (10% glucose) was available within 24 h before collection of urine. Controlled "clean" urinary samples were pooled and stored at 20 C. Fraction I-V from the urine were determined after ultrafiltration and Sephadex-G15. Amino-acid analysis of each fraction was automatically done by a 835 Amino-acid Analyzer, respectively. Bioassay was performed in 40 adult rabbits weighing 2.5-3.5 kg of either sex. Experiments were undertaken via the mesodiencephalic intraventricular infusion. Results show that S2C (Fraction-III) (50 micrograms/rabbit, i.c.v.) exhibited significant delta-enhancing effect compared to the controls. Further purification was done with Sephadex G-25 and Sephadex LH-20. The more purified S4B (50 micrograms/rabbit, i.c.v.) also exhibited significant delta-enhancing effect compared to the controls. The amino-acid analysis of Fraction-III revealed that the compositional contents of S2C and S4B are different from what have been known with Factor S, DSIP and SPS.

[Scanning electron microscopy of adult Trichuris trichiura]

The paper reports the result of the observation on the ultrastructure of the body surface of adult T. trichiura by scanning electron microscopy. Unique features of T. trichiura are described including the presence of labial-shape structures at the periphery of mouth, eight cephalic pores and a pair of amphids around the mouth pore and vesicle-shaped cuticular protuberances on the abdomen of T. trichiura. Cuticular pores were found scattering on the surface of T. trichiura. Detailed descriptions of male copulatory sheath and spicule were presented.

Differential regulation of multiple gap junction transcripts and proteins during rat liver regeneration

The mRNA and protein expression of alpha 1 (connexin 43), beta 1 (connexin 32), and beta 2 (connexin 26) gap junction genes were examined in the regenerating rat liver after 70% partial hepatectomy (PH). Expression of beta 1 and beta 2 steady-state mRNA levels changed minimally until 12 h after PH when both transcripts decreased to approximately 15% of baseline values. A similar decrease in assembled connexin levels was detected by immunoblot and indirect immunofluorescence at 18 h after PH. Both transcripts simultaneously increased between 24 and 42 h and again rapidly decreased by 48 h post-PH. beta 1 and beta 2 assembled gap junction protein expression increased at 48 h post-PH and rapidly decreased by 56 h. By 72 to 84 h post-PH, beta 1 and beta 2 mRNA and assembled protein expression returned to near baseline levels and were maintained. Interestingly, inhibition of protein synthesis with cycloheximide completely inhibited disappearance of the beta 2 transcript, in contrast to beta 1 mRNA which was unaffected. Nuclear run-on assays showed no change in transcriptional rates for either gene during the regenerative period. However, both beta 1 and beta 2 transcripts exhibited significantly decreased mRNA half-lives at 12 h post-PH (3.8 and 3.7 h, respectively) relative to those at 0 h (10.9 and 6.1 h, respectively). Surprisingly, although the transcriptional rate for alpha 1 was similar to that observed for beta 2, no alpha 1 transcripts were detectable by northern or RNase protection analysis. The results suggest that in the regenerating rat liver, beta 1 and beta 2 gap junction genes are not regulated at the transcriptional level. Rather, the cyclical modulation of their steady-state transcripts is regulated primarily by posttranscriptional events of which mRNA stability is at least one critical factor in the control process.

Cigarette smoking among junior high school students in Beijing, China, 1988

Prevalence, behavioural patterns and risk factors of cigarette smoking were studied in a sample of 8437 junior high school students in Beijing in 1988. Smoking at least occasionally was reported by 34.4% of boys and 3.9% of girls, though the intensity tended to be low. Smoking prevalence increased with age among boys. Inhaling smoke into the lungs was practised by 68.2% of the boys who smoked and 37.3% of the girls. 'Believing that one looks elegant when smoking', 'trying to be fashionable' and 'seeking stimulation' were the most important reasons for smoking. Of the boys 83.5% and of the girls 86.5% usually smoked with friends or schoolmates. Many more boys (19.2%) than girls (1.7%) smoked at home. Examinations of risk factors for teenage smoking showed that it was associated with a combination of familial, psychological and socio-school factors, with peer group pressure being the most important one.

[Clinical study of rapid bladder filling agent]

The Rapid Bladder Filling Agent (RBFA) was prepared with Polyporus umbellatus, Poria cocos and Furosemidum. The urinary volume and the best filling time of urinary bladder were observed with ultrasonography in 211 cases. The result showed that in experimental group the largest urinary volume in unit time was more than that in control group and shortest filling time was shorter (30.35 +/- 7.9 min) in comparing with control group (145.6 +/- 50.1 min). Clinical observation for 1180 cases proved that the RBFA had the effects of raising the quality of ultrasonographic examination and escalating work efficiency, shortening the waiting time of patients and relieving patients' suffering from excessive filling of urinary bladder. The effective time of the RBFA was fast but the duration was short. The RBFA had no adverse effect.

Studies on the Constituents of Adelostemma gracillimum

The glycone portion of the glycoside of ADELOSTEMMA GRACILLIMUM Hook. f. (Asclepiadaceae) was investigated. Three known polyoxypregnane ester-type aglycones, penupogenin ( 1) (1, 2), kidjoranine ( 2) (1, 3), and gagamine ( 3) (4, 5), and one new compound named gracigenin ( 4) were isolated and their structures were characterized on the basis of spectroscopic evidence, and that of ( 4) was determined by X-ray crystallography. It was found to possess an unprecedented 8,14- SECO-polyoxypregnane ester-type skeleton, and 4 is the first compound with this C (21)-steroid type skeleton to be found in nature.

DNA ploidy analysis of effectiveness of radiation therapy for cervical carcinoma

Cellular DNA content from 30 patients with cervical carcinoma was determined using flow cytometry before and after radiation therapy (RT). The authors attempted to correlate changes in DNA content, tumor response to RT, and post-RT pathologic findings. Before RT, tumors from eight of 30 patients (26.7%) were diploid or near-diploid; tumors from 22 patients (73.3%) were aneuploid. After RT, diploid or near-diploid tumors were found in 23 patients (76.7%), and aneuploid tumors were observed in seven patients (23.3%). Aneuploidy disappeared in 15 of the patient tumors, and complete tumor response (CR) was observed in 13 of these 15 patients (86.7%). Pathologic examinations were negative in 12 of 15 cases and suspicious in one of 15 cases. Of the seven patients whose tumor aneuploidy did not change after RT, CR was observed in only two (28.7%). Pathologic examinations were positive in five of seven cases and suspicious in one of seven cases. The CR for the 22 patients with pre-RT aneuploid tumors was 15 of 22 (68.2%); the CR for the eight patients with pre-RT diploid tumors was two of eight (25%, P less than 0.01). From these data the authors conclude there is a direct correlation between DNA content and radiosensitivity in cervical carcinoma. Aneuploid tumors from these patients were more radiosensitive than diploid tumors, and they patients had a better clinical tumor response and improved pathologic findings.

[Electrocardiogram analysis of adriamycin cardiotoxicity in 160 cases]

From January 1986 to May 1989, 160 cancer patients proven by pathology were treated by combined chemotherapy with adriamycin (ADM) as the chief agent. Of them, 20 were given simultaneous cyclophosphamide (CTX) and 14 had received mediastinal irradiation. 40 mg/m2 of ADM was given by rapid IV bolus injection which was repeated every 3 weeks. All but 9 had normal electrocardiogram (ECG) before ADM administration. In these 9 patients, when ADM reached certain accumulated dose, ECG showed no further changes. Thirty-seven (24.5%) cases had various types of abnormal ECG, manifested as arrhythmia in 11, non-specific ST-T changes in 12 and low voltage in 14. Of these 37 patients, fatal congestive heart failure developed in 4 cases. To reduce ADM cardiotoxicity, its indication should be strictly adhered to; ADM may be divided to two fractions on Day 1 and 2, for those patients receiving simultaneous CTX or who had had mediastinal irradiation, ADM accumulated dose should be limited to 400 mg/m2; ADM should never be given to patients with lowered QRS voltage greater than or equal to 30% of the normal value or with obvious ST-T changes; the accumulated doses should range from 450 to 550 mg/m2, simultaneous anti-histamines, anti-adrenaline, coenzyme Q10 and vitamin E are indicated.

A prospective study of nosocomial infections in cardiac surgery patients in China

A prospective survey of postoperative nosocomial infections (NI) in cardiac surgery was carried out in a cardiovascular specialty hospital in Beijing, China. During the period from December 1986 to December 1987, 1208 cardiovascular surgery patients were surveyed for NI. The overall incidence of NI was found to be 7.5%. The incidence of lower respiratory tract and wound infections were 4.5% and 2.9%, respectively. These two kinds of infection accounted for 78.1% of the total infections. After effective control measures were taken at the end of the first 6 months (December 1986 to May 1987) of the study, the incidence fell from 10.6% to 5.1% in the next 7-month period (June to December 1987). The pathogens causing NI were mostly gram-negative bacteria, and they were mainly opportunistic. The contribution of fungal infection was significant in the hospitals. The majority of the pathogenic isolates were highly resistant to the antibiotics commonly used in the hospital.

Economic effects of nosocomial infections in cardiac surgery

A study of 60 infected patients and matched controls showed that nosocomial infection in cardiac surgery cost each patient an additional 2207 yuan (pounds 290). The cost of multisite infection was much higher. Infected patients were in hospital for a mean of 14 extra days.

Expression and secretion of preS containing hepatitis B surface antigen in vaccinia virus system

The expression and secretion of preS containing hepatitis B surface antigen in vaccinia virus system was investigated. The human TK- 143 cells were infected with the recombinant vaccinia viruses vTMS-1 or vTLS-1. Cells infected with vTMS-1, which contains the preS2 + S gene, produced preS2 containing middle HBsAg proteins. Similarly, cells produced preS1 containing large HBsAg proteins upon infection with vTLS-1, which carries the preS1 + preS2 + S gene. The expression products could be secreted and form 22 nm particles. They reacted specifically with anti-preS1 and/or anti-preS2 monoclonal antibodies, and exhibited pHSA-receptor (for polymerized human serum albumin) activity. In addition, the major S components of hepatitis B surface antigen were also present in the products expressed by vTMS-1 and vTLS-1.

Application of a biotin-labelled DNA probe to detect Campylobacter

A procedure for direct detection of Campylobacter in feces has been developed using a biotin-labelled DNA probe. A species-specific probe (Bio-pCJ174 probe) for C. jejuni and a multivalent probe (Bio-pooled probe) for the thermotolerant Campylobacter species were developed with Bio-11-dUTP. Both probes were used to detect Campylobacter in 100 specimens of chicken feces. The coincidence rate of the results obtained by the Bio-pooled probe and cultivation was 90% and that of the Bio-pCJ 174 probe and cultivation was 96%. Identification of isolates was also carried out with both probes.

[Relation of placental prolactogen and E3 in the blood of pregnant women to placental grading by ultrasonography and its clinical significance]

Serum HPL and E3 of normal pregnant women and some pathologic pregnancies were dynamically measured and the relationship between their levels and placental gradings were investigated. The peak values of HPL and E3 were found in 13.16 +/- 7.49 and 15.68 +/- 6.51 days before delivery. The serum concentrations of the two hormones in women with severe PIH syndrome, postdate pregnancy and intrauterine fetal growth retardation (IUGR) were lowered. E3 declined earlier than HPL Analysis of the HPL, E3 levels in comparison with placental grading showed that the decline of the two hormones was mainly found in patients with grade III placenta.

[The appearance and changes of gap junctions during myogenesis of Cynops embryos]

The appearance and changes of gap junctions during the development of striated muscle cells of Cynops orientalis have been studied by paraffin section, ultrathin-section and freeze-etching techniques. Gap junctions first appear between the somitic mesoderm cells in the late gastrula. A marked increase of the number of gap junctions occurs at the end of gastrulation. The number of gap junctions remains at a high level from neural plate stage up to nasal pit stage. After the stage of muscle contraction, the number of gap junctions decreases. Gap junctions do not disappear until muscle cells have attained their final differentiation and neuromuscular junctions have fully developed. The changes of size of gap junctions parallel with the changes in number. In addition, the number and size of gap junctions are both at the high level before cell fusion. Therefore, it is possible to conclude that cell communication is closely correlated with the development of striated muscle cells. The role of communications in cell determination and differentiation and in cell fusion of muscle cells are discussed.