[Physiological changes in middle-aged persons and old people before and after tennis competition]

An examination of medical and physiological changes before and after tennis competition was performed on 71 middle-aged persons and old people in order to know whether they were adapted to this intense match or not. The result was that in the male group 1 (50-59 yrs), the heart rate, respiration rate and blood pressure before and after the tennis game had no significant differences (P > 0.05), indicating that this group was fit for the tennis competition, in the male group 2 (60-69 yrs) and male group 3 (70-79 yrs), as age advances, the number of unfitness to this game was increased gradually; in the female group (50-59 yrs), 28.5% of them showed a marked increase in the heart rate after the competition. We think that when persons have an electrocardiogram showing a significant undue changes of the ST segment and T wave after the contest, they are not suitable to this violent competition. So the medical surveillance is very important for the old people to play violent games such as tennis. The periodical health examination should be done before any exercise event with emphasis on the cardiovascular system so that the old sportsman can choose the proper exercise item and take self-control during the exercise.

[Radioimmunoassay of serum and CSF myelin basic protein and its application to patients with acute cerebrovascular accident]

Myelin basic protein (MBP) was measured in the serum and CSF of patients with acute cerebrovascular disease (CVD, 34 cases), demyelinating disorders (DMD, 30 cases) and other neurological diseases (OND, 26 cases) by using a double antibody radioimmunoassay (RIA). Patients with acute CVD had a mean serum MBP concentration and positivity rate much higher than those with DMD and OND. The differences were significant (P < 0.05). In CSF, MBP levels in patients with acute CVD and patients with DMD were significantly greater than those in OND patients (P < 0.05). The results also show that there was a linear relationship between the CSF MBP levels and the serum MBP levels in patients with acute CVD (r = 0.72, P < 0.01), but no such relationship in patients with DMD and OND. The amount of serum MBP was also significantly correlated to the severity of acute CVD, to the level of consciousness disorder and limb paralysis, and to the extent and site of the cerebral lesion at CT-scan (P < 0.05). This study shows that the measurement of brain specific MBP in serum as a marker of cerebral damage may have clinical value in the diagnosis and prognosis of patients with CVD.

[Alteration of calcium uptake and Ca(2+)-ATPase activity of cardiac sarcoplasmic reticulum in rat during ischemia-reperfusion]

Using Langendorff's perfusion model of isolated rat heart, the effect of period of ischemia, ischemia-reperfusion and changes in perfusate pH on the function of calcium uptake of cardiac sarcoplasmic reticulum (SR) was observed. The initial rate and capacity of calcium uptake by SR decreased significantly after 25 min ischemia, and were further worsened when ischemia was prolonged to 40 min. When hearts were subjected to 15 min reperfusion after 25 min ischemia, calcium uptake capacity and initial rate decreased even more in comparison with that of 40 min ischemia. In addition, the calcium dependent ATPase activity of SR was also markedly inhibited. Reperfusion with acid (pH 6.8) or alkaline (pH 8.0) made no significant difference on the aforementioned reperfusion induced changes. The results indicated that myocardial ischemia depressed the calcium transport activity of SR, and this depression was further aggravated with prolonging ischemia. Reperfusion after ischemia exacerbated the ischemic injury. Reperfusion with either acid or alkaline Krebs-Henseleit solution could not improve the calcium uptake function of SR, implying that the pH change does not seem to be an important factor in inducing the SR dysfunction during ischemia-reperfusion.

Purification of a Trypanosoma cruzi trypomastigote 60-kilodalton surface glycoprotein that primes and activates murine lymphocytes

We have purified a glycoprotein with a relative molecular mass of 60 kDa and present on the surface of Trypanosoma cruzi trypomastigotes and studied its ability to prime and stimulate the proliferation of murine spleen cells. T. cruzi trypomastigote membrane proteins were separated by preparative isoelectrofocusing. A trypomastigote 60-kDa surface protein with an isoelectric point of 4.2 was enriched by chromatofocusing and was readily purified in native form to homogeneity by gel filtration on a Superose column by use of a fast protein liquid chromatography system. Biotinylated wheat germ agglutinin, Ricinus communis agglutinin, and Datura stramonium agglutinin bound to blots containing the purified trypomastigote 60-kDa surface protein, indicating that this protein was glycosylated. The purified trypomastigote 60-kDa glycoprotein was recognized by antibodies produced during human infection, and immunoglobulin G against the purified glycoprotein immunoprecipitated a biotinylated 60-kDa molecule from the surface of trypomastigotes but not epimastigotes. Specific immunoglobulin G against the 60-kDa glycoprotein also increased the uptake of trypomastigotes and promoted parasite killing by macrophages. The purified 60-kDa glycoprotein was able to specifically activate primed lymphocytes, since there was a significant increase in [3H]thymidine incorporation by spleen cells obtained from CBA mice primed with this glycoprotein, with respect to control values. Furthermore, the 60-kDa glycoprotein did not stimulate unprimed spleen cells, indicating that the lymphoproliferation induced by this glycoprotein was specific and was not due to polyclonal activation. Our findings indicate that this T. cruzi trypomastigote 60-kDa surface glycoprotein primes and activates lymphocytes, which could lead to a beneficial immune response in the host.

[Histamine as modulator of potassium currents in ventricular cells isolated from heart of guinea pig. A possible regulator effect of ventricular electric activity]

Histamine is present in cardiac tissues in considerable amount, but its physiological role is not well understood. There are two kinds of histamine receptors on the cardiac cells (H1 and H2). Whereas the H2 actions are very well studied little is known about H1 effects. It has been reported that stimulation of H1 receptors induce a shortening of the action potential as a decrease in excitability, but the ionic mechanisms responsible for these are not known. The aim of the present paper is to explore the possible ionic mechanisms related to these effects on isolated ventricular myocytes by means of voltage clamp technique. Histamine induced a shift in the current-voltage relationship of the potassium background current to the right. This shift implies an increase in outward current at the plateau level, responsible for the shortening, as well as for the decrease in excitability. This is, as far as we know, the first report in potassium background channel modulation by an endogenous substance and firmly support the hypothesis that histamine is playing a role in cardiac modulation.

Nitrotriazoles bearing sulfur-substituted side chains: preparation and characterization as hypoxic cell radiosensitizers

A series of 3-nitro-1,2,4-triazole (NTA) derivatives with -(CH2)mC(= Y)NH(CH2)nZCH3(Y, Z = O or S; m = 1 or 2; n = 2 or 3) group in the side chain at the N-1 position of NTA and their fluorinated analogs were synthesized. Their physicochemical properties and radiosensitizing activities in vitro and in vivo were investigated with respect, particularly, to the effects of sulfur substitution on the side chain of triazoles. The sulfur substitution of the oxygen atom in the side chain of NTA derivatives increased the partition coefficient (P value), but had little effect on the one-electron reduction potential. The derivatives bearing a thioether group in the side chain were more effective in vitro on hypoxic EMT6/KU cells, but were less effective in vivo on SCCVII tumor than their oxygen analogs. The thioamide compounds showed almost the same or slightly higher sensitizing activities in vitro compared with their oxygen analogs.

[The effect of EBCI Iontophoresis on orthodontic tooth movement in rabbits]

The purpose of this study was to observe the effect of EBC ionophoresis on increasing the rate of tooth movement in rabbits.21 rabbits,in whose lower incisors the standard orthodontic appliances were placed,were divided into 3 groups at rendom which separately received iontoporesis of EBC,iontophosesis and injection of physiological saline at the submucosal area of the lower incisors.The results showed that the animals with EBC iontophoresis obtained tooth movement rate of 4.275+/-0.1214(mm) and the animals with NaCl iontophoresis and injection were respectively 3.337+/-0.4626(mm) and 2.178+/-0.2922(mm).The histological observation had also found the evidence of the ability of EBC to stimulate osteoclasts in preiodontal pression side and osteoblasts in tension.This study suggested that iontophoresis of EBC could play an important role in reconstructing the periodontum and speeding the tooth movement in rabbits.

Membrane affinity chromatography used for the separation of trypsin inhibitor

Polysulphone (PS) was chemically modified by acrylation-amination and by chloromethylation-amination, respectively. An ultrafiltration membrane of chemically modified polysulphone (CMPS) was prepared by the phase inversion method. Trypsin was then covalently bonded onto the CMPS membrane by diazotization. The activity of immobilized trypsin reaches up to 10200 U/g; 15 mg trypsin was immobilized on 1 g CMPS membrane. Separation of soybean trypsin inhibitor was carried out on the affinity membrane, yielding 6.5 mg pure trypsin inhibitor in one run. The enzyme membrane has good activity and stability.

Attachment of Trypanosoma cruzi to host cells: a monoclonal antibody recognizes a trypomastigote stage-specific epitope on the gp 83 required for parasite attachment

A set of monoclonal antibodies against the purified surface gp 83 of T. cruzi trypomastigotes was produced and the ability of these monoclonals to inhibit the attachment of trypomastigotes to heart myoblasts was investigated. Western blots of solubilized trypomastigotes, epimastigotes or amastigotes probed with this set of monoclonal antibodies show that the gp 83 is present in invasive trypomastigotes, but not in non-invasive epimastigotes or amastigotes. One monoclonal antibody (Mab 4A4) from this set inhibits the attachment of trypomastigotes to heart myoblasts, whereas the others (MAbs 2H6, 4B9, 2D11) do not. These results show that the Mab 4A4 recognizes an epitope on the gp 83 of invasive trypomastigotes required for parasite binding to host cells.

Comparison of incidence, mortality and treatment of acute myocardial infarction in hospitals in Japan and China

Acute myocardial infarction (AMI) is one of the most intractable diseases and is increasing rapidly in Japan and China. Two hospitals in Japan and China, the Critical Care Center of Kurume University Hospital and the Chinese Beijing 309 Hospital in China (abbreviated to Beijing 309 Hospital) were compared. The incidence, mortality and treatment of AMI were investigated in both hospitals from 1989 to 1991. The incidence of AMI for all patients admitted during the three years was 5% in Kurume University Hospital and 4.7% in Beijing 309 Hospital, which are similar rates. The average age of the patients in Beijing 309 Hospital was younger (58 +/- 13) than in Kurume University Hospital (64 +/- 11). The mortality rate in Kurume University Hospital was slightly lower than the rate in Beijing 309 Hospital (8.1% vs 8.9%). Thrombolytic therapy was actively performed in both hospitals. In Kurume University Hospital, urokinase (UK: 71.4%) or recombinant tissue plasminogen activator (rt-PA: 28.6%) was administered by intravenous (85.7%) and intracoronary percutaneous transluminal coronary recanalization (PTCR: 14.3%) injection. In Beijing 309 Hospital, UK (32.7%) or snake poison enzyme (SPE: 62.3%) was administered by intravenous (85.8%) or intra-aortic (14.2%) injection. Rt-PA was only used in Japan and SPE was only used in China, but both had very strong fibrinolytic effects and resulted in high success rates of coronary reperfusion. The incidence of direct coronary intervention with percutaneous transluminal coronary angioplasty (PTCA) and intra-aortic balloon pumping (IABP) for cardiogenic shock was much higher at Kurume University Hospital than at Beijing 309 Hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic regulation of pigment formation of Onosma paniculatum cultured cells

The pigment yields of Onosma paniculatum callus and suspension cultured cells were increased 5.5 and 8.1 fold of that of the control respectively, when 10(-5) M of copper ion was added into the medium. The pigments synthesis was also stimulated greatly when 10(-5) M of L-phenylalanine was added into the medium and the cells were cultured for twenty-one days. The maximum yield of pigments was obtained when 10(-6) M of ascorbic acid was added to the medium.

Metabolic rate modification of nitrotriazole radiosensitizers by sulfur substitution of side chain

The pharmacokinetic properties and radiosensitizing activities in vitro and in vivo of a series of 3-nitro-1,2,4-triazole (NTA) derivatives with a -CH2(C = Y)NH(CH2)nZCH3 (Y, Z = O or S; n = 2 or 3) group in the side chain at N-1 position of NTA were investigated with respect, particularly, to the effects of sulfur substitution in the side chain of NTA. The sulfur substitution for an oxygen atom in the side chain NTA radiosensitizers increased the rho value, but gave rise to little effect on the one-electron reduction potential. The derivatives bearing a thioether group (-CH2SCH3) in the side chain were slightly less effective both in vitro on hypoxic EMT6/KU cells and in vivo on SCCVII tumors than their oxygen analogs (-CH2OCH3). The thioether compounds tended to metabolize rapidly. The thioamide compound showed high sensitizing activity in vitro, but metabolized very slow.

Characteristics of physiological tremor in five fingers and evaluations of fatigue of fingers in typing

Physiological tremor, which is the invisible mechanical vibration of body part, was measured for five fingers. It was obtained that the power spectrum always has two peaks at 10 and 25Hz for each of the five fingers. The peaks were considered to be generated in the following two loop systems: The component of the lower frequency originated from the central nervous system as a long loop, and that of the higher frequency originated from the muscle-spine loop system as a short loop. The total power, which was the sum of power spectra ranging from 1.5 to 50Hz, was defined as an evaluation index, and it showed characteristic results for the five fingers. The muscular load produced by two hours of typing work was responsible mainly for the increase of total power and for the change of peak frequencies. The mechanism for the change of the power spectrum due to muscular load was well explained by the two-loop theory. It was found that the fatigue of the fingers due to muscular load could be evaluated by the total power.

Noble metal abundances in an Early Archean impact deposit

We report detailed analyses on the concentrations of the noble metals Pd, Os, Ir, Pt, and Au in an early Archean spherule bed (S4) of probable impact origin from the lower Fig Tree Group, Barberton Greenstone Belt, South Africa. Compared to other sedimentary deposits of known or suspected impact origin, some noble metals are present in exceptionally high concentrations. Noble metal abundances are fractionated relative to abundances in chondrites with ratios of Os/Ir, Pt/Ir, Pd/Ir, and Au/Ir at only 80, 80, 41, and 2% of these values in CI chondrites. Although an extraterrestrial source is favored for the noble metal enrichment, the most plausible cause of the fractionation is by regional hydrothermal/metasomatic alteration.

Identification and cloning of a granule autoantigen (carboxypeptidase-H) associated with type I diabetes

Using serum from a prediabetic patient as a probe, we screened 0.5 x 10(6) recombinants from a rat islet lambda gt11 expression library. One plaque-producing antigen reactive with this prediabetic serum was identified, subcloned, and sequenced. Analysis of the sequence reveals that the clone encodes a 136-amino acid fragment of carboxypeptidase-H (enkephalin convertase). Carboxypeptidase-H is a molecule expressed within islet secretory granules and neurendocrine cells. The patient whose antibodies recognize this recombinant molecule (termed DG-1) was negative for anti-DG-1 antibodies in 1984, developed the antibodies by 1986, and remained positive until the development of diabetes in 1988. To date, serum from 5 of 20 cytoplasmic islet cell antibody-positive relatives reacted with the expressed protein, while none of 14 control sera reacted. On Western blotting, the initial patient's serum used for the screening reacts with a 52-kDa antigen corresponding to the mol wt of the membrane form of carboxypeptidase-N. The current study has identified carboxypeptidase-H as an autoantigen recognized by serum of pretype I diabetes, and the methodology used should aid in identification of additional autoantigens associated with type I diabetes.

[A study of textile noise influence on maternal function and embryo-growth]

Ninety hundred seventy-eight female textile workers exposed to noise (greater than or equal to 85 dB (A)) were recruited as the subjects of observation group, and 402 nonexposed female workers were chosen as the controls (less than 75 dB (A)). According to noise level, the observation group was subdivided into three groups: group 1, 100-104 dB (A), 416 workers; group 2, 95-99 dB, (A), 310 workers; group 3, 85-94 dB (A), 252 workers. Non-conditional logistic regression model was used to exclude the effect of mixed factors, such as age and working life. The result showed that noise-exposure could have some adverse effect on reproductive function of women and embryo growth. The workers exposed to noise had significantly increased incidence rates for irregular menstrual cycle, dysmenorrhea, lumbago, hypertension in pregnancy, threatened abortion, spontaneous abortion, premature labour, dystocia and low birth weight of newborns. When the noise intensity heightened, the sorts of abnormal function of reproduction increased and the risk of incidence raised too. These demonstrated a dose-response relationship between the noise intensity and incidence rate. The noise-working life had significant effects on the incidence of hypertension in pregnancy and prematurity. Although the age had some influence, it was not statistically significant. In terms of the maternal function and embryo growth, the factors in order of risk are: noise intensity greater than working life greater than age.

An antihypertensive factor in the erythrocytes of essential hypertensive subjects--effects on blood pressure and calcium uptake by vascular tissue in rats

An extract prepared from the erythrocytes of essential hypertensive subjects was found to significantly lower systolic blood pressure (SBP) in spontaneously (SHR) and renal hypertensive rats (RHR) following a single intravenous or intraperitoneal injection: The maximum SBP reduction was 42.8 mmHg in SHR and 38.3 mmHg in RHR. In contrast, this hypertensive factor (AHF) had little effect on normotensive Wistar Kyoto and Wistar rats. AHF was also found to significantly suppress Ca2+ uptake by vascular smooth muscle in the mesenteric artery and aorta of hypertensive and normotensive rats (P less than 0.05, respectively). Furthermore, AHF prepared from the erythrocytes of normotensive subjects was shown to have a similar effect.

[Radioimmunoassay of serum myelin basic protein]

Using purified human brain myelin basic protein (MBP) to raise antiserum in rabbits and to prepare 125I-labelled MBP (chloramine-T method), We have established a high specific, precise and sensitive double-antibody radioimmunoassay for the measurement of human serum MBP. The sensitivity was 0.5 ng/ml. In the present study, the serum samples of thirty patients with various neurological diseases were detected. An important clinical implication is that serum MBP level should serve as an index for the damage degree of central neurological diseases.

Evidence of an EGF/TGE-alpha--independent pathway for estrogen-regulated cell proliferation

To elucidate the relationship between epidermal growth factor (EGF)/transforming growth factor (TGF-alpha) and estradiol-17 beta (E) in cell proliferation, we examined their effects on the breast cancer cell line, CAMA-1. While E was able to consistently induce cell proliferation under a variety of experimental conditions, EGF/TGF-alpha was without effect. Despite the presence of the receptor (EGFR) gene, mature EGFR protein and mRNA were not detected by radioreceptor assay, 35S Met-labelling, and the Intron Differential RNA/PCR method under conditions in which cells remain responsive to E. Furthermore, TGF-alpha is not an autocrine factor in CAMA-1 cells. We demonstrated unequivocally that EGF/TGF-alpha interaction with EGFR is not an obligatory event in mediating estrogen-stimulated cell proliferation.

A fluorinated 2-nitroimidazole, KU-2285, as a new hypoxic cell radiosensitizer

To develop new hypoxic cell radiosensitizers, we incorporated fluorine atoms into the side chain of the 2-nitroimidazole. Of the resulting compounds, KU-2285 (a 2-nitroimidazole with an N1-substituent of CH2CF2CONHCH2-CH2OH) was considered the most useful as a hypoxic cell radiosensitizer. In this study, its in vivo radiosensitizing activity and acute toxicity were compared with those of etanidazole. The reduction potentials of KU-2285 and etanidazole were -0.96 V and -1.05 V vs Ag/Ag+ in N,N-dimethylformamide, respectively, and their respective octanol/water partition coefficients were 0.25 and 0.040. The in vivo radiosensitizing activity of KU-2285 was found to be similar to that of etanidazole at the same administration dose when assayed by an in vivo-in vitro assay, a growth delay assay, and a tumor control assay using SCC VII tumor or transplanted mammary tumor in C3H/He mice. Although the radiosensitizing activity of etanidazole was reduced when it was administered orally, there was no significant difference in the radiosensitizing activity of KU-2285 whether it was administered intravenously, intraperitoneally, or orally. The acute toxicity measured as the LD50/7 in 8-week-old female C3H/HeJ mice was found to be 2.4 g/kg (intravenously), 2.1 g/kg (intraperitonealy), and 4.25 g/kg (orally) for KU-2285, whereas it was 4.75 g/kg (intravenously) for etanidazole.

Reproductive factors and colorectal cancer risk among Chinese females

We report results from a population-based case-control study of colorectal cancer among Chinese women in western North America (NA) and the People's Republic of China (China). A common protocol was used to assess reproductive characteristics and hormone use of 395 Chinese women (189 from NA and 206 from China) with cancer of the colon or rectum and of 1112 age-matched Chinese controls (494 from NA and 618 from China). In NA, risks for cancers of both the colon and rectum were lower among parous compared to nulliparous women (odds ratio for colorectal cancer, 0.6, P = 0.08), but the trend in risk was not smooth with increasing number of livebirths. This association with parity was absent for both cancer sites in China. There were no consistent patterns in the relationships between other reproductive factors (including age at menarche, age at first livebirth, menopausal status) and risk of colon and rectal cancer on either continent.

[Status of Yunnan drug banxia and its botanical origin]

L. Yunnan, the medicinal material Banxia recorded in The Pharmacopoeia of the People's Republic of China (1985 ed.) is called "Dizhu Banxia" (stem tuber of Pinellia ternata). Besides, "Shanzhu Banxia" (stem tuber of Arisaema yunnanense, A. bathycoleum, A. saxatile and A. prazeri) is also used medically as Banxia, while "Gouzhua Banxia" (stem tuber of Arisaema franchetianum, A. likiangense and Pinellia pedatisecta) is not.

Purification of Trypanosoma cruzi surface proteins involved in adhesion to host cells

We have identified four surface 83 kDa proteins of pI values 6.3, 6.4, 6.5 and 6.6 in T. cruzi trypomastigotes which specifically bind to rat heart myoblasts. These proteins were purified by isoelectric focusing and anion-exchange chromatography in an FPLC system. These 83 kDa proteins inhibit the attachment of trypomastigotes to myoblasts in a concentration-dependent manner, indicating that these trypomastigote proteins mediate the attachment of trypomastigotes to heart myoblasts.

[Inhibitory effect of secretin on gastric motility in isolated vascular perfused rat stomach]

Effect of secretin on gastric motility was studied on the preparation of isolated vascular perfused rat stomach. The results showed: (1) Secretin markedly inhibited spontaneous as well as pentagastrin stimulated antral motility. (2) Antisecretin serum completely abolished the inhibitory effect of secretin on antral motility. (3) Antisomatostatin serum and indomethacin blocked the inhibitory effect on antral motility induced by secretin. The results indicated that the inhibitory effect of secretin might be produced through direct action of secretin on secretin receptors and mediated partially by the local somatostatin and prostaglandin in gastric antrum.

[The measurement of p30 level in the normal human seminal plasma by the Beckman immunochemistry system using anti-30 serum]

This paper is the first report about the measurement of p30 level in the normal human seminal plasma by the Beckman immunochemistry system (ICS) using anti-p30 serum. The p30 levels of 108 samples of normal human seminal plasma were measured. The range of p30 level was 0.2996-4.3913 mg/ml. The square root transformation statistical analysis indicated that the coefficient of skewness was 0.0237 the coefficient of kurtosis was -0.8854, the p30 level in normal human seminal plasma fitted the square root normal distribution, the mean was 1.6236 mg/ml and the standard deviation was 0.1641 mg/ml.

[Anti-anaphylactic pharmacological action of water-soluble constituents of Ginkgo biloba L. episperm]

Water-soluble constituents of Ginkgo biloba episperm 100 or 200 mg/kg po given to mice inhibited passive cutaneous allergic response and the same dose given to rats ip inhibited mast cell degranulation. It antagonized the contractile effect of isolated guinea pig ileum smooth muscles induced by the antigen. It inhibited the deliverance of SRS-A from anaphylactic lung of guinea pig.

Diet, physical activity, and colorectal cancer among Chinese in North America and China

In a population-based case-control study of colorectal cancer among Chinese men and women in western North America and the People's Republic of China, a common protocol was used to assess past life-style characteristics of 905 cases diagnosed during 1981-1986 and 2,488 controls. Risks for cancers of both the colon and rectum increased with increased food energy from fat, protein, carbohydrate, and all energy sources combined, for both sexes and on both continents. Yet, in multivariate analysis, colorectal cancer risk was significantly associated only with saturated fat; no relationships were seen with other dietary sources of energy. Colon cancer risk was elevated among men employed in sedentary occupations. On both continents and in both sexes, risks for cancers of both the colon and rectum increased with increasing time spent sitting. Further, the association between colorectal cancer risk and saturated fat was stronger among the sedentary than among the active. Risk among sedentary Chinese Americans of either sex increased more than fourfold from the lowest to the highest category of saturated fat intake. Among migrants to North America, risk increased with increasing years lived in North America. These observations suggest (a) that colorectal cancer risk increases with duration of exposure to a sedentary life-style and a diet rich in saturated fat; (b) that higher incidence among Chinese-American men relative to women is due to longer duration of these habits among men, who have lived longer in North America; and (c) that higher risk among Chinese Americans of both sexes relative to risk among the general population in China is due to differences in such habits. Attributable risk calculations suggest that, if these associations are causal, saturated fat intakes exceeding 10 g/day, particularly in combination with physical inactivity, could account for 60% of colorectal cancer incidence among Chinese-American men and 40% among Chinese-American women.

[Sedative-hypnotic effect of caulis Polygoni multiflori decoction]

The sedative-hypnotic effect of Caulis Polygoni multiflori decoction (CPMD) was studied by the rolling cylinder method in mice and by the somnopolygraphic recording method in rats. The result from the rolling method in mice showed that CPMD (9g/kg) did have synergic action with the subthreshold hypnotic dose of sodium pentobarbital (20mg/kg). The result from the somnopolygraphic recording experiment showed that the immediate hypnotic effect of an effective dose of CPMD (20g/kg) was basically similar to that of diazepam (5mg/kg) used under the same experimental condition, chiefly an increase in the duration of slow wave sleep phase (SWS) and a decrease in the duration of paradoxical sleep phase (PS). By the end of a three-day session in dose of twice a day the hypnotic effect appeared more prominent and the reduction of SWS latency became significant.

KIH-802, an acetohydroxamic acid derivative of 2-nitroimidazole, as a new potent hypoxic cell radiosensitizer: radiosensitizing activity, acute toxicity, and pharmacokinetics

The radiosensitizing activity, acute toxicity, and pharmacokinetics of a new hypoxic cell radiosensitizer, potassium 2-nitroimidazole-1-acetohydroxamate (KIH-802), were compared with those of misonidazole (MISO) and etanidazole (SR-2508). The radiosensitizing activity of KIH-802 was slightly higher than that of MISO and SR-2508 in vitro and was similar to or slightly higher than that of MISO or SR-2508 in vivo. The acute toxicity of KIH-802 was slightly higher than that of MISO. The concentrations of KIH-802 in the brains and peripheral nerves of mice were as low as those of SR-2508 and lower than those of MISO.

A family of positive regulators related to the Pseudomonas putida TOL plasmid XylS and the Escherichia coli AraC activators

The XylS family consists of a least 8 different transcriptional regulators. Six of these proteins are positive regulators for the catabolism of carbon sources (benzoate and sugars) in Escherichia coli, Pseudomonas putida and Erwinia carotovora, and two of them are involved in pathogenesis in Escherichia coli and Yersinia enterocolitica. Based on protein alignments, the members of this family exhibit a long stretch of homology at the C-terminal end. The regulators involved in the catabolism of carbon sources stimulate transcription from their respectively regulated promoters only in the presence of effectors. In two of the regulators, mutations at the non-homologous N-terminus alter affinity and specificity for effectors while mutations at the conserved C-terminus part decrease activation of transcription from their corresponding regulated promoters. It is thus probable that the variable N-terminus end in this family of regulators contains the motif involved in effector recognition, while the C-terminal end is involved in DNA-binding. These proteins seem to be related by common ancestry and may act through similar mechanisms of positive regulation effected through similar folding patterns.

Supplementary iodine fails to reverse hypothyroidism in adolescents and adults with endemic cretinism

The efficacy of supplemental iodine in correcting hypothyroidism in adults and older children with endemic myxedematous cretinism is not known. To investigate this issue we administered im iodized oil (1.5 mL) to 28 hypothyroid endemic cretins (TSH, greater than 5 mIU/L) from western China, aged 14-52 yr (mean = 29 SD = 11 yr). Clinical examination, intelligence testing (Hiskey Nebraska Test of Learning Aptitude and the Griffiths Mental Development Scales), and thyroid function tests were performed before and 6 months after iodine supplementation. We found that signs of thyroid hormone deficiency, dwarfism, and delayed sexual maturity persisted after iodine supplementation. Further, mental disability and other clinical features of neurological damage were not altered by treatment. The mean serum concentration of total T4 before treatment was 75 nmol/L (SD = 40) and fell after iodized oil administration to 56 nmol/L (SD = 29; P less than 0.001). Mean serum levels of TSH before and after iodine showed a paradoxical fall [85 mIU/L (SD = 102) and 46 mIU/L (SD = 46), respectively]. Serum TSH levels decreased into the normal range (less than 5 mIU/L) in only 1 of 28 patients (4%). We conclude that iodine supplementation does not reverse thyroid hormone deficiency or its sequelae in adolescents and adults with endemic myxedematous cretinism. Iodized oil in this age group of patients with endemic cretinism does not appear to be beneficial and should be used with caution.

An important role of endogenous insulin on exocrine pancreatic secretion in rats

We have investigated a physiological role of endogenous insulin on exocrine pancreatic secretion stimulated by a liquid meal as well as exogenous secretin and cholecystokinin octapeptide (CCK-8) in conscious rats. Each rat was prepared with a chronic pancreatic fistula and an indwelling catheter in a jugular vein. Oral ingestion of a liquid meal (5 ml) resulted in significant increases in pancreatic secretion, including volume, bicarbonate, and amylase output, in these rats. A rabbit anti-insulin serum (1.0 ml) given intravenously completely blocked the postprandial exocrine pancreatic secretion, whereas a normal rabbit serum did not influence the pancreatic secretion in the same rats. When pancreatic secretion was stimulated by intravenous administration of both secretin and CCK-8 in three different doses, including 0.015, 0.03, and 0.06 clinical unit and microgram.kg-1.h-1, respectively, volume, bicarbonate, and amylase output increased significantly in a dose-dependent manner. This increase in pancreatic secretion was also completely blocked by a rabbit anti-insulin serum, whereas it was not influenced by a normal rabbit serum. The amount of the antiserum employed abolished the postprandial increases in plasma insulin concentration. We conclude that endogenous insulin plays an important role on the regulation of postprandial pancreatic secretion in rats. Furthermore, for the stimulatory action of the two intestinal hormones secretin and CCK-8 on the pancreatic exocrine secretion, endogenous insulin is need.

[Short-term curative effect of cultured Cordyceps sinensis (Berk.) Sacc. Mycelia in chronic hepatitis B]

33 cases of chronic hepatitis B. patients treated with cultured Cordyceps sinensis mycelia have shown that the drug improves the liver function, promotes negative transfer HBsAg, and markedly helps to raise plasma albumin, resist high gamma globulin and to adjust body immunocompetence. It is therefore suggested that cultured Cordyceps sinensis mycelia may be used as a medicine for chronic hepatitis B. patients in adjusting protein metabolism and correcting inversion of albumin and globulin.

[Effects of CCK-8 of hypothalamus on antral motility in rats]

Cholecystokinin-octapeptide (CCK-8) of 10 ng were injected into lateral hypothalamus (LH) and ventromedial hypothalamus (VMH) in conscious rats, both of which brought about inhibition of antral motility recorded by a strain gauge, the actions were partly antagonised by bilateral vagotomy, but blocked by intravenous infusion of atropine or regitine. It is suggested that both vagus and sympathetic nerves be involved in mediation of function of central CCK-8. In addition, the unit spontaneous discharges of neurons in vagal nuclei were attenuated while CCK-8 injected into LH. On the contrary, the antral motility was stimulated markedly by injection CCK-8-antiserum into LH, indicating that the endogenous CCK-8 in this area exercises a continuous restraint on antral motility in the basal state. CCK-8 cells both in LH and VMH were visualized by PAP method. It may be reasonable to refer this as the histological basis of the identical function on antral motility exercised by CCK-8 both in LH and VMH.

[Inhibition of gastric acid secretion by vascularly perfused secretin and somatostatin in isolated rat stomach]

Effects of secretin and somatostatin on acid secretion and its relation to prostaglandin E, I2 release in the totally isolated vascularly perfused rat stomach were studied. The results showed: (1) Secretin and somatostatin both markedly inhibited acid secretion stimulated by pentagastrin. Indomethacin could reverse the inhibitory effects of acid secretion by secretin and somatostatin. (2) Secretin increased PGE and PGI2 metabolite 6-Keto-PGF1 alpha release significantly. Somatostatin only increased PGE release. Indomethacin could block stimulatory affects of secretin on PGE, 6-Keto-PGF1 alpha release and somatostatin on PGE release. These results indicated that: (1) inhibition of acid secretion by secretin was mediated by PGI2 and PGE release; (2) inhibition of acid secretion by somatostatin was mediated only by PGE release.

A new, potent 2-nitroimidazole nucleoside hypoxic cell radiosensitizer, RP170

The radiosensitizing activity, acute toxicity and pharmacokinetics of RP170, a new hypoxic cell radiosensitizer, were compared with those of misonidazole (MISO) and SR2508. RP170 belongs to the group of 2-nitroimidazole nucleosides, which are designed to be selectively excluded from the neural tissue. The reduction potential of RP170 was similar to that of MISO and SR2508. The partition coefficients in octanol/water of RP170, MISO, and SR2508 were 0.094, 0.35, and 0.021, respectively. The radiosensitizing activity of RP170 was similar to that of MISO and SR2508 in vitro and in vivo. There was no significant difference in the radiosensitizing activity of RP170 in vivo between intravenous and intraperitoneal administration. The acute toxicity of RP170 was the same as that of SR2508. Pharmacokinetic evaluation showed that the concentration of RP170 in the brain was as low as that of SR2508. RP170 is expected to have the same radiosensitizing effects as MISO and SR2508, and to be less neurotoxic than MISO.

[Multinucleated giant cells in cultured giant cell tumor of bone]

Further observations on multinucleated giant cells (MGCs) in 12 giant cell tumors of bone (GCT) were made, by means of tissue culture, electron microscopy and immunohistochemistry. In continuous in vitro culture, two distinct types of MGCs were found and herein termed preliminarily short-lived MGCs and long-lived MGCs respectively. The former type had limited life span of about 2-3 weeks, whereas the latter type of MGCs maintained growth or continual formation. They had entirely different appearance and characteristics. This fact reflects two types of MGCs exist in GCT in vivo. Besides, the origin of MGCs were also investigated and discussed in considerable depth.

Contrast study on multinucleated giant cells in giant cell tumors of bone and other multinucleated cells

By means of tissue culture, electron microscopy, cytochemistry, indirect immunofluorescence and immunohistochemistry, the multinucleated giant cells(MGCs) in 12 giant cell tumors of bone (GCT) were studied in contrast with osteoclasts (OCs), foreign body giant cells (FGCs) and inflammatory giant cells (IGCs). The findings in the majority of MGCs were identical with those in OCs, suggesting that they most probably derived from the same precursor. Continuous in vitro culture revealed two kinds of MGCs, which were designated preliminarily as short-lived MGCs and long-lived MGCs for their difference in morphology and in several biological features, which suggests two kinds of MGCs exist in GCT. We conclude that the short-lived conform to the typical MGCs known generally to the pathologists, while the long-lived are deemed to be closely related to the neoplastic elements of the tumor.

A retrovirus vector which transduces a functional estrogen receptor gene at high efficiency

A high titer retroviral vector containing the cDNA of human estrogen receptor (hER) was generated and used to transfer the hER gene into the rat 208F cell line. Southern blot analysis showed the integration of the provirus to be at a unique site and that the provirus was intact in the genome of recipient cells. The expression of the integrated hER gene in the infected rat cells was detected by Northern blot analysis and by a functional assay in which the hER gene product stimulated the production of a chloramphenicol acetyl transferase gene under the control of an estrogen-responsive element. These experiments demonstrate the feasibility of using a retroviral vector system to introduce a functional ER gene into cultured cells lacking this receptor.

Characteristics of fluorinated nitroazoles as hypoxic cell radiosensitizers

Types of 2-nitroimidazoles and 3-nitro-1,2,4-triazoles bearing one or two fluorine atoms on their side chains were synthesized to evaluate their physicochemical properties, radiosensitizing effects, and toxicity. The reduction potential of the compounds containing one fluorine was similar to that of misonidazole (MISO), whereas that of the difluorinated compounds was slightly higher. Both mono- and difluorinated compounds had an in vitro sensitizing activity comparable to or slightly higher than that of MISO. The fluorinated 3-nitrotriazoles were almost as efficient as the 2-nitroimidazoles with the same substituent. In vivo, some of the compounds were up to twice more efficient than MISO, whereas others were as efficient as MISO. Toxicity in terms of LD50/7 in mice was quite variable depending on the side-chain structure; the amide derivatives were less toxic than MISO, whereas the alcohol and ether derivatives were more toxic. In view of the radiosensitizing effect and toxicity in vivo, at least one compound, KU-2285 (a 2-nitroimidazole with an N1-substituent of: CH2CF2CONHCH2CH2OH) has been found to be as useful a hypoxic cell sensitizer as SR-2508.

Importance of tumor affinity of nitroazoles in hypoxic radiosensitization

In vitro and in vivo sensitizing activities of a variety of nitroazole derivatives including misonidazole (MISO), SR-2508, and RSU-1069 were correlated by the aid of pharmacokinetic measurements of the drug uptake in animal solid tumors. The sensitizer enhancement ratio in vivo (SERvivo) on solid tumors increased linearly with the square root of administrated dose (Ds). The specific activity (A) in vivo of nitroazoles was evaluated from the square-root empirical relationship, SERvivo = 1.00 + A D1/2S. The intratumor concentration of nitroazoles at a given time t after administration was in proportion to the DS, in which the proportional constant was defined as the tumor-affinity factor FT,t. The absolute molar activity alpha M defined by A(M/FT,t)1/2, where M is the molecular weight of nitroazoles, showed a linear relationship with the SER in vitro (SERvitro) at 1 mM of sensitizers. The sensitizer dose required to achieve an SERvivo of 1.5 (DS,1.5) decreased and thus the overall sensitizing efficiency on animal solid tumors increased as the FT,t became greater.

[Antidotal effect of Stenoloma chusanum(L.) Ching against arsenic and ammonium]

The antidotal effect of four extracts from Stenoloma chusanum on acute poisoning of mice caused by arsenic and ammonium chloride was observed. The result shows: extracts B and C can reduce the mortality of mice remarkably, while extract C can raise the tolerance of mice by raising their LD50 from 31.1 +/- 4.3 mg/kg to 38.2 +/- 5.9 mg/kg. In the case of the mice poisoned by ammonium chloride, the four extracts can also reduce the mortality, but make no significant difference as compared with the control group statistically (P greater than 0.05).