Tissue and perfusate pharmacokinetics of melphalan in isolated perfused rat hindlimb

Melphalan is commonly used as a cytotoxic agent in isolated limb perfusion for locally recurrent malignant melanoma. The time course of melphalan concentrations in perfusate and tissues during a 60-min melphalan perfusion and 30-min drug-free washout in the single-pass perfused rat hindlimb was examined using a physiologically based pharmacokinetic model. The rat hindlimbs were perfused with Krebs-Heinseleit buffer containing 4.7% bovine serum albumin (BSA) or 2.8% dextran 40 at a constant rate of 3.8 ml/min. The concentration of melphalan in perfusate and tissues was determined by high-performance liquid chromatography. The tissue concentrations of melphalan were significantly higher with the perfusate containing dextran than BSA during the 60-min perfusion. During the washout period, the melphalan concentration in the perfusates decreased rapidly in first few minutes, followed by a slower monoexponential decline. The estimated half life (t1/2) for melphalan removal from skin and fat was 59 +/- 2 min for both BSA and dextran perfusates. However, the estimated t1/2 for melphalan removal from muscle was 79 and 96 min for BSA and dextran washout perfusates, respectively. The predicted concentration-time profiles obtained for melphalan with BSA and dextran perfusates appear to correspond closely to the observed data. This study showed that the uptake of melphalan into perfused tissues is impaired by the use of perfusates in which melphalan is highly bound. Melphalan washout from muscle, but not skin and fat, was facilitated by the use of perfusates in which melphalan is highly protein bound.

[Effect of yishen xiezhou recipe on mesangium cell of chronic renal failure rats]

OBJECTIVE

To observe the effect of Yishen Xiezhuo Recipe (YSXZR) on glomerular mesangium cell (MSC) proliferation.

METHODS

YSXZR was given to healthy and experimental CRF rats by gastrogavage, and the effect of their serum on MSC proliferation was observed.

RESULTS

The serum could obviously inhibit the MSC proliferation. Compared with control rats to which physiological saline was given, the difference was significant (P < 0.01).

CONCLUSION

YSXZR could postpone CRF progress.

Resolution and response-time dependence of ferroelectric liquid-crystal optically addressed spatial light modulators on grating profiles

We introduce a model to analyze the time response of an optically addressed spatial light modulator (OASLM) when a two-dimensional image is written on it. Comparison with experimental results is performed by use of gratings as input images. For a given spatial frequency, we show that the response time of the device depends on the grating profile. The effect of the time-constant mechanism is demonstrated theoretically and experimentally for a sinusoidal-wave and a square-wave intensity profile. An alternative explanation for the resolution limitation of the OASLM that is related to the time-constant mechanism and a new method for measuring the resolution of the device are proposed.

Melphalan dosing regimens for management of recurrent melanoma by isolated limb perfusion: application of a physiological pharmacokinetic model based on melphalan distribution in the isolated perfused rat hindlimb

The optimal dosing schedule for melphalan therapy of recurrent malignant melanoma in isolated limb perfusions has been examined using a physiological pharmacokinetic model with data from isolated rat hindlimb perfusions (IRHP). The study included a comparison of melphalan distribution in IRHP under hyperthermia and normothermia conditions. Rat hindlimbs were perfused with Krebs-Hen-seleit buffer containing 4.7% bovine serum albumin at 37 or 41.5 degrees C at a flow rate of 4 ml/min. Concentrations of melphalan in perfusate and tissues were determined by high performance liquid chromatography with fluorescence detection. The concentration of melphalan in perfusate and tissues was linearly related to the input concentration. The rate and amount of melphalan uptake into the different tissues was higher at 41.5 degrees C than at 37 degrees C. A physiological pharmacokinetic model was validated from the tissue and perfusate time course of melphalan after melphalan perfusion. Application of the model involved the amount of melphalan exposure in the muscle, skin and fat in a recirculation system was related to the method of melphalan administration: single bolus > divided bolus > infusion. The peak concentration of melphalan in the perfusate was also related to the method of administration in the same order. Infusing the total dose of melphalan over 20 min during a 60 min perfusion optimized the exposure of tissues to melphalan whilst minimizing the peak perfusate concentration of melphalan. It is suggested that this method of melphalan administration may be preferable to other methods in terms of optimizing the efficacy of melphalan whilst minimizing the limb toxicity associated with its use in isolated limb perfusion.

Altered vascular norepinephrine responses in portal hypertensive intestine: role of PKA and guanylate cyclase

The purpose of the present study was to determine whether selective blockade of adenosine 3',5'-cyclic monophosphate (cAMP)- or guanosine 3',5'-cyclic monophosphate (cGMP)-mediated events modulated norepinephrine responses in intestinal microvessels of normal and portal hypertensive rats. Vascular norepinephrine responses were evaluated before and after inhibition of cAMP-dependent protein kinase [protein kinase A(PKA)] with Rp-adenosine 3',5'-cyclic monophosphothioate (Rp-cAMPS) or guanylate cyclase with LY-83583. Male Sprague-Dawley rats were divided into two groups: those with portal hypertension by portal vein stenosis and normal controls. The small intestine was prepared for microcirculatory studies. Arteriolar diameter and erythrocyte velocity were monitored, and microvascular flow was calculated from velocity and diameter data. The preparation was challenged with incremental concentrations of norepinephrine before and after addition of Rp-cAMPS (50 microM) or LY-83583 (30 microM). Arteriolar diameter and blood flow were significantly elevated in portal hypertensive rats; norepinephrine responses were significantly depressed. LY-83583 did not alter arteriolar diameter, blood flow, or norepinephrine responsiveness in normal or portal hypertensive rats. Rp-cAMPS did not affect arteriolar diameter, blood flow, or norepinephrine responsiveness in normal rats. However, in portal hypertensive rats, Rp-cAMPS reduced blood flow by approximately 20% (P < 0.05) and completely restored vascular norepinephrine responses to normal. The results indicate that cAMP- but not cGMP-dependent events are primarily responsible for the loss of microvascular norepinephrine responsiveness in portal hypertensive intestine.

The effects of perfusion conditions on melphalan distribution in the isolated perfused rat hindlimb bearing a human melanoma xenograft

An isolated rat hindlimb perfusion model carrying xenografts of the human melanoma cell line MM96 was used to study the effects of perfusion conditions on melphalan distribution. Krebs-Henseleit buffer and Hartmann's solution containing 4.7% bovine serum albumin (BSA) or 2.8% dextran 40 were used as perfusates. Melphalan concentrations in perfusate, tumour nodules and normal tissues were measured using high-performance liquid chromatography (HPLC). Increasing the perfusion flow rates (from 4 to 8 ml min(-1)) resulted in higher tissue blood flow (determined with 51Cr-labelled microspheres) and melphalan uptake by tumour and normal tissues. The distribution of melphalan within tumour nodules and normal tissues was similar for both Krebs-Henseleit buffer and Hartmann's solution; however, tissue concentrations of melphalan were significantly higher for a perfusate containing 2.8% dextran 40 than for one containing 4.7% BSA. The melphalan concentration in the tumour was one-third of that found in the skin if the perfusate contained 4.7% BSA. In conclusion, this study has shown that a high perfusion flow enhances the delivery of melphalan into implanted tumour nodules and normal tissues, and a perfusate with low melphalan binding (no albumin) is preferred for maximum uptake of drug by the tumour.

[A histopathologic study on recovering effect of kangdu shengxue decoction on spleen and thymus of mice with radiation injury]

The effect of Kangdu Shengxue Decoction (KDSXD) on the spleen and thymus of mice irradiated with 80Co gamma-rays has been studied by histopathological methods. 130 LACA mice were divided into 3 groups. Control and experimental groups were generally irradiated for once with 8 Gy 80Co gamma-rays. The experiment of group were treated with KDSXD one hour before irradiation and consecutively five days after radiation. The results of experiment showed that 30 days after irradiation the structure of spleen and thymus of treated mice normalized. The difference of recovery between control and experimental group showed a high significance statistically (P < 0.01).

High-performance liquid chromatographic assay for the measurement of melphalan and its hydrolysis products in perfusate and plasma and melphalan in tissues from human and rat isolated limb perfusions

A sensitive, specific and rapid reversed-phase high-performance liquid chromatographic (HPLC) assay was developed for the quantitation of melphalan and its hydrolysis products in samples from the isolated perfusion of human and rat limbs. Samples of perfusate, plasma and tissue were analysed, following methanol precipitation, using a phenyl column and fluorescence detection. Dansyl-arginine (38 micrograms ml-1) was employed as the internal standard. Good resolution was observed allowing quantitation of melphalan, monohydroxymelphalan (MOH) and dihydroxymelphalan (DOH) in perfusate and plasma were all 100 +/- 10%. The recovery of melphalan in tissue was 93.5%. A linear response was demonstrated for melphalan in the concentration range 1.8 - 56.8 micrograms ml-1, for DOH in the concentration range 0.5 - 30.0 micrograms ml-1 and for MOH in the range 1.4-25.1 micrograms ml-1, in perfusate and plasma. The lower limits of quantitation of melphalan, MOH and DOH in perfusate and plasma were 1.4, 2.4 and 1.2 ng on column, respectively, and 7.2 ng of melphalan on column in tissue. Intra-assay coefficients of variation (C.V.) for melphalan, MOH and DOH, at low and high concentrations were all less than 5% and the inter-assay C.V.s were less than 9%. An ultra-filtration study to determine the protein binding of melphalan and the hydrolysis products showed that the unbound fractions (fu) of melphalan in buffer containing dextran and bovine serum albumin were 0.873 and 0.521, respectively. The assay was used to quantitate melphalan and its hydrolysis products in samples from isolated perfusions in the human limb and rat hindlimb.

Influence of physicochemical parameters and perfusate flow rate on the distribution of solutes in the isolated perfused rat hindlimb determined by the impulse-response technique

The relationship between solute distribution, physicochemical properties, and tissue physiology was determined by the impulse-response (IR) technique and statistical moment analysis in the isolated perfused rat hindlimb. The concentration of bovine serum albumin (BSA; 2, 4.7, and 7%, w/v), perfusate flow rate (4 and 8 mL/min), and solute physicochemical properties (lipophilicity, P, fraction unbound to protein, fu; fraction ionized, fi; and molecular weight MW) were varied to better understand the underlying determinants of solute distribution. An apparent low availability was found for a number of the solutes as a consequence of tissue sequestration. This low availability precludes the estimation of an apparent volume of distribution (V) for these solutes. The V of solute and tissue (skin, fat, and muscle) blood flow increased with perfusion flow rate (p < 0.01). The unbound distribution volume (Vu) of basic solutes was significantly linear with respect to P. Multiple linear regression analysis showed that the distribution volume of solute in tissue was significantly related to fu (p < 0.01), but not improved by including relationships to P, MW, and fi. Data obtained with this IR technique yield results consistent with in vivo studies in terms of the importance of fu as a determinant of V. This work has shown that the estimations of solute V by the IR technique in a single-pass preparation are unreliable for solutes with a low availability due to apparent solute sequestration into tissue. The parameter V may also be affected by changes in the perfused limb physiology associated with the perfusion conditions used. The Vs for lidocaine and diazepam vary with fu in accordance with deductions based on the results of steady-state studies.

Effects of propranolol on intestinal microcirculation of normal and portal hypertensive rats

BACKGROUND/AIMS

The goal of the present study was to compare the efficacy of locally and systemically administered propranolol in normal and prehepatic portal hypertensive rats, and to test the hypothesis that beta-adrenoceptor blockade reduces intestinal arteriolar diameter by allowing unopposed alpha-adrenergic activity.

METHODS

The small intestine was prepared for in vivo microcirculatory studies and transferred to an intravital microscope where arteriolar diameter and erythrocyte velocity were continuously monitored. First order arteriolar (1A) blood flow was calculated from the product of mean velocity and microvessel cross-sectional area. In separate experiments, diameter responses of 2A and 3A were monitored. Once steady-state conditions were achieved, the preparation was challenged by topically applied doses of propranolol (0.01-100.00 microM) in the presence and absence of the alpha-receptor antagonist, phentolamine. In a separate group of experiments, the effects of systemically administered propranolol (10 mg/kg body weight) were evaluated before and after local alpha-adrenoceptor blockade.

RESULTS

Propranolol produced significant vasoconstriction and decreased blood flow in both normal and portal hypertensive rats. Portal hypertensive arterioles exhibited an attenuated response to propranolol. Local administration of phentolamine completely blocked the propranolol-induced diameter changes. Comparison of equivalent concentrations of local and systemic propranolol indicated that both routes of administration were equally effective.

CONCLUSION

The results of the present study suggest that the cardiovascular actions of propranolol are predominantly mediated through blockade of peripheral beta 2-adrenoceptor.

Effects of gender and pregnancy on hepatocellular uptake of palmitic acid: facilitation by albumin

The human serum albumin (HSA)-dependent unbound clearance (Clu) of [3H]palmitic acid (PA) by hepatocyte suspensions isolated from immature and mature male and female and pregnant female rats was studied. The Clu values obtained experimentally were compared with the predictions of a noncompartmental diffusion-reaction (Bass-Pond) theory for the cellular uptake of protein-bound ligands. In all groups, as the concentration of HSA (Ca) was increased, there was a striking increase in Clu. These enhancement factors were predicted by the theory. Adult females had higher Clu values at high Ca values than males or immature females. Furthermore, at high Ca values, Clu in pregnant animals was twice as high as in the nonpregnant animals and four times as high as in the aged-matched males. The absolute values of Clu obtained experimentally in both pregnant and nonpregnant females exceeded the maximal predictions of the theory, using reasonable values of all of the parameters. Thus, according to current data on the physicochemical characteristics of the uptake system, the study demonstrates that some specialized process exists to facilitate hepatocellular uptake of fatty acid from albumin, and that it is potentiated by the female sex hormones.

Nonreceptor-mediated intestinal vasoconstriction in portal hypertensive rats

Previous studies have demonstrated that receptor-mediated vasoconstriction is impaired in chronic portal hypertension (PH). Furthermore, it has been suggested that altered vasoconstrictor effectiveness in chronic PH is due to a defect in the intracellular events associated with smooth muscle activation and not to impaired coupling of vasoconstrictors with vascular smooth muscle receptors. The present study was designed to determine whether nonreceptor-mediated vasoconstrictor responses are impaired in the PH intestinal microcirculation. Specifically, we examined the effects of aluminum fluoride-induced activation of G proteins, KCl-induced depolarization, caffeine-induced release of intracellular Ca2+, and l-indolactam-induced activation of protein kinase C on the intestinal microcirculation of normal (Norm, n = 39) and PH (n = 42) rats. The small intestine was prepared for microcirculatory studies and transferred to a video microscope. First-order arteriolar (1A) diameter and red cell velocity were measured on-line. Blood flow was calculated from the product of velocity and microvessel cross-sectional area. After a control period, the microvasculature was exposed to a solution containing aluminum chloride plus sodium fluoride, potassium chloride, caffeine, or l-indolactam. Maximal decreases in arteriolar diameter produced by aluminum fluoride, KCl, caffeine, and l-indolactam were significantly greater in Norm rats when compared with PH rats. Changes in arteriolar blood flow were also larger in Norm than in PH rats. The results of the present study provide the first direct evidence of an impaired response to second-messenger activation in the PH circulation.

120 x 100 pixel antiblooming array based on optically addressed ferroelectric liquid-crystal cells

We describe the principle and the operation of a 120 x 100 pixel antiblooming array. Each cell in the array is made up of a hydrogenated amorphous silicon photoconductor layer driving a ferroelectric liquid-crystal shutter. The device is designed to be coupled with a CCD camera to prevent high-blooming overload and image lag.

Alterations of auditory nerve responses by hypoxia in normal and hydropic ears of awake guinea pigs

Total interruption of blood or oxygen supply to the inner ear produces very rapid and drastic effects, whereas moderate decreases can be well tolerated by normal ears. In experimental endolymphatic hydrops some moderate alterations of cochlear vasculature have been described which might affect cochlear adaptation to moderate blood or oxygen deficiencies. In order to test this hypothesis an hypoxia at 5% oxygen was imposed for 30 min in normal and hydropic ears of awake guinea pigs and cochlear function was monitored with an electrode at the round window. Electrophysiological recordings used measures of compound action potential (CAP) amplitudes evoked by high-intensity tones, and of CAP thresholds. In normal ears hypoxia induced threshold elevations at all frequencies and decreases of CAP amplitude only for high frequencies. Hydropic ears presented similar or smaller threshold elevations but showed CAP amplitude decreases extending to lower frequencies and showed a much slower recovery both for CAP thresholds and amplitudes. The data indicate that hypoxia had different effects on auditory nerve responses evoked by high versus low intensity tones. The deleterious effects of hypoxia were increased in hydropic ears. Hypoxia-induced alterations were measured twice at one week intervals during which an anti-ischemic drug was administered to the animals; some beneficial effects of the drug treatment were observed on normal but not on hydropic ears.

Vascular NE responsiveness in portal hypertension: role of portal pressure and portosystemic shunting

Previous studies have suggested that the development of portal venous collaterals and subsequent portosystemic shunting is the key event responsible for the reduced vasoconstrictor effectiveness in chronic portal hypertension. The purpose of the present study was to test this hypothesis. Thirty-nine male Sprague-Dawley rats were divided into four groups: end-to-side portacaval shunt (PCS, n = 11), chronic prehepatic portal hypertension (CPH, n = 10), acute prehepatic portal hypertension (APH, n = 8), and sham-operated controls (Sham, n = 10). The small intestine was prepared for microcirculatory studies. First-order arteriolar diameter and erythrocyte velocity were measured on-line, and blood flow was subsequently calculated. Once steady-state values were obtained the preparation was topically exposed to incremental doses of norepinephrine. The half-maximal effective dosage (ED50) for maximal vasoconstriction (diameter response) was significantly increased in PCS (4.5 microM) and CPH (1.5 microM) compared with Sham (0.8 microM). However, the ED50 was significantly lower in APH (0.17 microM) than in Sham. Similarly the ED50 for maximal blood flow reduction was higher in PCS (2.4 microM) and CPH (1.2 microM) compared with Sham (0.2 microM). The results demonstrate that vascular norepinephrine responsiveness is reduced in both portacaval shunted and chronic portal hypertensive rats, but not in acute portal hypertension. These data indicate that portosystemic shunting, not portal pressure elevation, is the key event leading to the reduced vascular norepinephrine responsiveness observed in CPH conditions.

Selenol binds to iron in nitrogenase iron-molybdenum cofactor: an extended x-ray absorption fine structure study

The biological N2-fixation reaction is catalyzed by the enzyme nitrogenase. The metal cluster active site of this enzyme, the iron-molybdenum cofactor (FeMoco), can be studied either while bound within the MoFe protein component of nitrogenase or after it has been extracted into N-methylformamide. The two species are similar but not identical. For example, the addition of thiophenol or selenophenol to isolated FeMoco causes its rather broad S = 3/2 electron paramagnetic resonance signal to sharpen and more closely approach the signal exhibited by protein-bound FeMoco. The nature of this thiol/selenol binding site has been investigated by using Se-K edge extended x-ray absorption fine structure (EXAFS) to study selenophenol ligated to FeMoco, and the results are reported here. EXAFS data analysis at the ligand Se-K edge was performed with a set of software, GNXAS, that provides for direct calculation of the theoretical EXAFS signals and least-squares fits to the experimental data. Data analysis results show definitively that the selenol (and by inference thiol) binds to Fe at a distance of 2.4 A. In contrast, unacceptable fits are obtained with either Mo or S as the liganded atom (instead of Fe). These results provide quantitative details about an exchangeable thiol/selenol binding site on FeMoco in its isolated, solution state and establish an Fe atom as the site of this reaction. Furthermore, the utility of ligand-based EXAFS as a probe of coordination in polynuclear metal clusters is demonstrated.

[Diagnosis of ovarian tumors by sonography]

A retrospective study was carried out in 406 cases to analyse ultrasound feature of ovarian tumor and compared with pathological specimen. The aim is to suggest a new classification of ovarian tumors in ultrasonography. According to the pathological reports the ovarian tumors were divided into five groups, and found out the ultrasonographic characteristic feature of benign or malignant. The results showed that the new classification of ovarian tumor has a better method. The diagnostic accurate rate is 90.9%. In addition, we described the characteristic feature of five groups of ovarian tumors by sonography and discussed the role in early diagnosis of malignant ovarian tumors and improvement five year survival rate.

Effect of intracerebroventricular injection of 6-hydroxydopamine on the peripheral catecholamine and angiotensin II in SHR

This investigation revealed that the contents of A II and NE in plasma, heart and aorta and E content in plasma were significantly increased in SHR at the age of 12th week. At the same time the systolic blood pressure of SHR was much higher than that of the age-matched WKY. The intracerebroventricular administration of 6-OHDA in SHR at the age of 8th week not only prevented the development of hypertension, but also reduced the contents of NE and E in the brain regions, heart, aorta and plasma. Simultaneously A II content in heart, aorta and plasma was decreased. These results suggested that: 1. the renin-angiotensin system and peripheral sympatho-adrenal system are overactive in SHR, 2. the overactivity of peripheral sympatho-adrenal system is dependent on the central catecholaminergic neurons, and 3. the action of sympatho-adrenal system is partly responsible for the increase of A II content in plasma, heart and aorta in SHR.

Physiological pharmacokinetics of solutes in the isolated perfused rat hindlimb: characterization of the physiology with changing perfusate flow, protein content, and temperature using statistical moment analysis

Distribution of Evans Blue (EB), sucrose, and water into the isolated perfused rat hindlimb was studied under various conditions using the multiple indicator dilution (MID) technique. Statistical moment analysis of the outflow profiles for the EB, sucrose, and water were used to define the vascular, extravascular, and total water spaces, respectively. The varied perfusion conditions included albumin content (2, 4.7, and 7%), temperature (25, 37, and 42 C), perfusate flow rate (2, 4, 8, and 12 ml/min) and the presence/absence of red blood cells. The range of studies undertaken were chosen to represent the variety of conditions used in the preparation of both isolated animal and human limbs, the latter being particularly important in cytotoxic therapy for recurrent malignant melanoma. The distribution volumes of EB, sucrose, and water were dependent on the flow rate and the albumin content of perfusate. The normalized variances (CV2) of the markers were of the following order: sucrose (2.18) > water (1.58) > EB (0.68), indicating that some disequilibrium occurs during the capillary exchange of water and sucrose. It is suggested that a Krebs-Henseleit buffer containing 2% BSA is a suitable perfusate for most studies of the isolated rat hindlimb perfusion. The effect of albumin concentration manifests itself only at higher flows.

Is asymptomatic bronchial hyperresponsiveness an indication of potential asthma? A two-year follow-up of young students with bronchial hyperresponsiveness

To determine the possibility that asymptomatic bronchial hyperresponsiveness (BHR) develops into symptomatic asthma, a two-year follow-up study was conducted in 81 students (48 male, 33 female; 11 to 17 years) who were found to have BHR in a 3,067 population survey (BHR group). Eighty-eight age-matched students (48 male, 40 female) with normal bronchial responsiveness served as control subjects. Daily symptom cards were recorded. Peak expiratory flow rate was measured for 24 h when symptoms occurred. Histamine inhalation tests were performed at the beginning of the study and at the end of the first and the second year. In the BHR group, 58 students remained bronchial hyperresponsive at the end of follow-up. Nine of 31 students with initially diagnosed bronchial asthma had their symptoms relieved entirely, but ten asymptomatic students developed asthma. The incidence of newly diagnosed asthma (12.5 percent in the BHR group or 20 percent in the asymptomatic BHR group) and the total percentage of diagnosed asthma (39.5 percent) in the BHR group were significantly higher than those (2.27 percent, 2.27 percent) in the control group. FVC and FEV1 showed no significant difference between two groups. PD20 FEV1 values in newly diagnosed asthmatics were significantly lower than those in asymptomatic students both at the beginning (3.05 +/- 1.56 mumol vs 6.14 +/- 1.60 mumol, p < 0.05) or the end (3.47 +/- 1.73 mumol vs 6.55 +/- 1.51 mumol, p < 0.05). The percentage of early respiratory illness was significantly higher in those with newly diagnosed asthma (80 percent) than in asymptomatic students (22.3 percent), but atopic index and the percentage of parental asthma showed no difference between two groups. In nine asthmatics whose symptoms were relieved entirely in the two-year follow-up, PD20 FEV1 was undetectable within the cumulative dose of 7.8 mumol of histamine in three students and rose from 4.58 +/- 1.85 mumol to 7.62 +/- 1.02 mumol in the remaining six. The higher the BHR, the more likely the students developed asthma. About 45 percent of asymptomatic students with PD20 < or = 3.2 mumol developed asthma in the following two years and 80 percent of them had a history of early respiratory illness, suggesting that they may have subclinical or potential asthma.

[Pharmacokinetics of epostane in rabbits by HPLC method]

Epostane (Epo), a 3 beta-hydroxysteroid dehydrogenase inhibitor, interrupted pregnancy in rats, rhesus monkeys, and women. Epo concentrations in serum were determined by high performance liquid chromatography (HPLC) at 0.25, 0.5, 1, 2, 4, 8, 16, 32, and 48 h after intragastric Epo 96 mg.kg-1 in rabbits. The concentration-time curve exhibited a 2-compartment open model. The pharmacokinetic parameters were: T1/2ka 0.79 +/- 0.08 h, T1/2 alpha 0.96 +/- 0.08 h, T1/2 beta 6.6 +/- 1.5 h, Vc 14 +/- 3 ml.kg-1, AUC 12.0 +/- 1.9 micrograms.h.ml-1, Tmax 1.8 +/- 0.5 h, Cmax 3.3 +/- 0.5 microgram.ml-1. After rat copora luteum were incubated with hCG 10 IU.ml-1 and Epo 10 or 100 micrograms.ml-1 for 18 and 48 h, luteal cells showed various degrees of degeneration and progesterone production was significantly inhibited.

Parkinson's disease in China. Coordinational Group of Neuroepidemiology, PLA

An epidemiological study on the incidence and prevalence of Parkinson's disease (PD) was carried out in 29 provinces, cities and autonomous regions in this country in 1986. The survey was conducted in 117 areas, and 566 patients with PD were found among 3,869,162 persons examined, giving a point prevalence for men and women of 16.9/10(5) and 12.4/10(5), with the highest prevalence after the fifth decade of age. The disease was most prevalent in the southern part of China, especially in Hunan and Guangxi provinces. The incidence was 1.5/10(5)/yr in 1986. Both the prevalence and incidence of PD in China are lower than those in the white race and Japanese.

[Central norepinephrine and angiotensin II contents in the brain regions of spontaneously hypertensive rats (SHR) and the interaction between them]

The norepinephrine (NE) and angiotensin II (A II) contents in the brain regions of SHR and WKY (Wistar Kyoto) rats at different ages were determined by fluorospectrophotometry and radioimmunoassay. The systolic blood pressure (SBP) of the rats was measured indirectly with a tail cuff technique in conscious state. The results were as follows: There was no significant difference in the central A II and NE contents between SHR and WKY rats at 8-week age. Since 12th week age the SBP of SHR has increased gradually, up to 16th to 20th week and then maintained steady level. Whereas there was no significant change of SBP in WKY rats in the same span of age. In the early and late states of hypertension the A II contents in the medulla oblongata, pons, hypothalamus and nucleus caudatus of SHR were markedly higher than those of the age-matched WKY rats. But the change of NE content of SHR in the early stage showed a different picture as compared with that of WKY rats, i.e., NE decreased in medulla oblongata and anterior hypothalamus but increased in pons, posterior hypothalamus and nucleus caudatus. However, in the late stage there was no such significant difference between SHR and WKY rats. Consequently, it is suggested that the central A II and NE participated in the development of hypertension of SHR, and that the maintenance of hypertension is mainly dependent upon the increased A II content. Microinjection of captopril or 6-OHDA in the lateral cerebroventricle of SHR elicited a decrease of BP and reduction of both A II and NE contents in the medulla and hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

Disturbed nonlinear multispecies models in ecology

We analyze a disturbed form of the general Lotka-Volterra model of an ecosystem with m interacting species. The disturbances act on the intrinsic growth rates of the species and are assumed to be bounded but otherwise unknown. We employ a Lyapunov technique and the concept of "reachable set" from control theory to estimate the set of all possible population densities that are attainable as a result of the disturbances. To calculate estimates for this reachable set, a number of numerical methods that entail the solution to one or more global optimization problems are developed. Specific examples involving two, three, and four species are solved. We also derive an explicit analytical expression that represents an estimate for the reachable set in the m-dimensional case. The estimate is conservative but can be evaluated without carrying out any optimization procedure. We show that methods developed in this paper can be applied to certain other types of nonlinear ecosystem models.

Relationship of menopausal status and sex hormones to serum lipids and blood pressure

Arterial blood pressure and serum lipids were measured in 598 Chinese women aged 40-54 years. Menopausal or post-menopausal women had higher means of serum cholesterol, triglyceride and HDL-cholesterol, and had higher prevalence of hypertension, hypotension, hypercholesterolaemia and hypertriglyceridaemia than premenopausal counterparts. There were no differences in means of systolic and diastolic pressures among pre-menopausal, menopausal and postmenopausal women. Fat Synergic Index was first used in this study instead of Quetelex Index, and it was found that Fat Synergic Index is the strongest factor which affects serum cholesterol, triglyceride, HDL-cholesterol and systolic and diastolic blood pressure in multiple linear regression analyses. The role of oestradiol, progesterone and testosterone in three serum-lipid multiple regression models are different, but they are similar in systolic and diastolic blood pressure regression models. Conditional logistic regression analysis found that progesterone is a protective factor only and testosterone is one of the risk factors for hypertension.

[Relation of hepatic pathologic changes and portal venous pressure in the course of cirrhosis in rats]

In order to pinpoint the site causing increased intrahepatic vascular resistance, we observed the relationship between hepatic pathologic changes and free portal pressure (FPP) during the development of CCl4-induced liver cirrhosis of rat. The results suggested that the degeneration necrosis and regeneration of liver cells, and consequent stenosis, or obliteration of sinusoidal spaces caused by the swelling and disarrangement of the liver cell plates led to the occurrence of portal hypertension. The possibility of pre- or post-sinusoidal obstruction was excluded by the manifestation of the pathologic lesions. It is the authors' belief that the exact site of the increased intrahepatic vascular resistance was most likely at the level of hepatic sinusoids. Furthermore, there was certain positive correlation between plasma glucagon concentration and FPP, indicating that glucagon was also involved in the pathogenesis of portal hypertension.

[Prediction of ovulation]

Prediction of ovulation was carried out by B-ultrasonography, BBT graph, cervical mucus and appearance of mittelschmerz in 45 normally menstruation women for a total of 72 cycles. LH peak values were also determined in 20 cases (20 cycles). The results were as follows: 1. The relation-ship between each index and ovulation: (1) The ultrasound image of follicle: average daily follicular growth during the 4-5 day before ovulation was 2.5 +/- 2.1 mm (means +/- s). Average diameter of the biggest follicles one day before ovulation was 20.6 +/- 2.0 mm. (2) The change of cervical mucus: the opening of external os and the secretion of mucus with ferning became most typical one day before the ovulation. (3) BBT graph: in a majority of cycles, ovulation occurred at the first day of the initial rise in temperature. (4) Mittelschmerz: occurred in 35% of cycles and appeared within 24 hours before ovulation. (5) LH peak value: ovulation occurred 24 to 48 hours after the first significant rise of LH, and within 24 hours after LH peak value. 2. The relation-ship between indices: in the majority of cases, when we employ the ultrasound image of follicular rupture as a signs of ovulation, LH peak value, follicle of biggest diameter, maximum volume of cervical mucus, the lowest point of BBT and mittelschmerz appear on the same day, namely, one day before ovulation. The authors suggest that ultrasonography used combination with other parameters provides a feasible and relatively accurate and reliable method for the prediction of ovulation in clinical practice.

[The diagnosis of intracranial A.V. malformation with orbital involvement by B-scan, colour Doppler and CT scan]

20 patients with intracranial A.V. malformation with orbital involvement were examined by B-Scan (Real- time ophthascanB). colour doppler (Acason 128) and CT scan. These patients were confirmed in clinically and other examination. Ultrasonography Showed dilated superior ophthalmic vein and its pulsating which are Synchroniged with the heart beating; the echo-free cavity changed in shape upon compression with the probe and some thickened extraocular muscles. The flowing counter pulsating and volume of blood stream were showed clearly in colour doppler. CT scan showed dilated superior ophthalmic vein, thickened extraocular muscles and dilate shadow of cavernous sinus. If strengthen scan to be done, the malformation of cerebrum artery and vein can be showed clearly. These examination are of value in diagnosis. The rate of ultrasound and CT scan for the differential-diagnosis was discussed.

The effect of tamoxifen on the function and lifespan of the corpus luteum and on subsequent ovarian function

The aim of the present study was to investigate the effects of tamoxifen on pituitary and luteal function and on the bleeding pattern when administered continuously in the secretory phase. The study included 16 women with regular menstrual cycles followed during one control, one treatment and one follow-up cycle. Each volunteer received 20 mg tamoxifen twice daily from cycle day 18 to menstruation in the treatment cycle. The luteal phase was slightly, but significantly prolonged during treatment, and FSH, progesterone, 17-hydroxyprogesterone, 20 alpha- dihydro progesterone, estrone, estrone sulphate and estradiol significantly elevated in comparison with corresponding data during the control cycle. The results indicate that estrogen may be of some importance for the regulation of the life span of the corpus luteum in the human. The significantly elevated levels of pregnanediol glucuronide and estrone glucuronide during the follow-up cycle are most likely a result of either a direct effect of remaining circulating tamoxifen levels on the ovary, or mediated through the increased release of FSH. If estrogens are of importance for the process of implantation, which has recently been suggested in sub-human primates, also in the human remains unclear. Studies on the effect of anti-estrogens on the endometrium during the secretory phase of the cycle are ongoing.

Lack of effect of high-dose antioestrogen on the maturation and in-vitro fertilization of human oocytes

Thirty-four women requesting laparoscopic sterilization underwent a fixed schedule regimen for multiple follicular development which included norethisterone and clomiphene citrate. Follicle aspiration for oocyte recovery was attempted laparoscopically 34 h after administration of 5000 IU human chorionic gonadotrophin (HCG). Nineteen women were given 80 mg tamoxifen orally 4 h prior to HCG injection, while 15 acted as controls. There was no statistical difference in fertilization rates in vitro between tamoxifen-treated patients and controls (80 and 68% respectively). In addition, the morphological characteristics of the oocytes, the rates of cleavage, and the concentrations of oestradiol, progesterone and androstenedione in follicular fluid were similar in the two groups. Tamoxifen was detected in substantial amounts in follicular fluids of patients given tamoxifen. These results suggest that high-dose tamoxifen, in clinically used doses, does not adversely affect the final stages of maturation or the fertilization and early cleavage of human oocytes.

Metabolic derangement of glucose, bile acid and amino acids after portasystemic shunts in cirrhotic rats

Carbon tetrachloride was used to induce cirrhosis in 81 Wistar rats. The animals were divided into three groups to receive end-to-side mesocaval shunt (MCS), end-to-side portacaval shunt (PCS) and Sham operation as control, respectively. Dynamic values of blood glucose and hormones for regulating glucose metabolism, SGPT, serum glycine conjugated cholic acid (CCA) and free serum amino acids were determined and compared with those obtained from 10 normal rats. The determinations suggested that the insulin level depended on the severity of hepatocellular damage with hyperglucagonemia after portasystemic shunt, and CCA was markedly elevated in MCS rats after interruption of the enterohepatic circulation. Changes of CCA were also influenced by hyperglucagonemia and poor liver function in PCS rats. Increase in the aromatic amino acids (AAA) level was related to the impaired hepatic function and hyperglucagonemia. However, decrease in the branched-chain amino acids (BCAA) level was not likely in response to the serum insulin level. Therefore, it is concluded that imbalance of serum amino acids has partial relationship with the derangement of glucose metabolic hormones.