[The changes in transmembrane potential and ionic currents induced by "ischemia" in sheep cardiac Purkinje fibers]

Ischemia-mimic solution (hypoxia, hyperkalemia, acidosis, no substrate) induced changes of transmembrane potential and ionic current were observed in 24 sheep cardiac Purkinje fibers. The sequence of changes of transmembrane potential was as follows: Two to three min after perfusion with ischemia-mimic solution, the maximum diastole potential (MDP) was depolarized slightly, and attended by a decrease of depolarization rate of phase 4 while the action potential duration (APD) was shortened or underwent a shortening-prolongation-re-shortening process. Then, the plateau of action potential disappeared gradually. As MDP was depolarized further, the action potential amplitude (APA) and the excitability of the Purkinje fibers decreased continuously until action potential could no longer be elicited. The whole process took 30 min to 160 min in different preparations. When the APD was shortened, the instantaneous outward current was always increased at all membrane potential levels. The steady-state current-voltage relationship (CVR) curve was changed from S shape to a straight line, and the inward rectification phenomenon disappeared. Under ischemic condition, the amplitude of Isi was decreased from 6.74 +/- 4.48 nA to 0.86 +/- 1.39 nA, and the CVR curve shifted more to the negative. The above results indicate that under the ischemic condition, the pacemaker function of cardiac Purkinje cell is inhibited, a large amount of K+ ions outflows and inward current Isi is decreased. These changes may be the reasons for the genesis of ischemic arrhythmia.

[Survey on tick vectors of Lyme disease spirochetes in China]

Since 1987 we have been studying on Lyme disease in China. There were 71 isolates of Borrelia burgdorferi recovered from six species of ticks including Ixodes persulcatus, Ixodes granulatus, ixodes rangtangensis, Haemaphysalis concinna. Haemaphysalis bispinosa and Haemaphysalis longicornis, and 55 isolates from Ixodes persulcatus collected from Heilongjiang, Jilin, Liaoning, Nei-Monggol, Hebei and Xinjiang region (province). Ixodes persulcarus is the dominant species accounted for more than 80% of the total number of collected ticks, 20 or 45 per cent adult Ixodes persulcatus contained spirochetes as determined by direct immunofluorescence in the northeast and northwest. The seasonal change of adult Ixodes persulcatus is coincident with that of the patient with Erythema migrant. These studies proved that Ixodes persulcatus play the leading role in transmission of Borrelia burgdorferi to human in north region of China. It is not clear what species of tick is the principle vector in the south region of China, though the spirochetal isolates were cultivated from Haemaphysalis bispinosa, Ixodes granulatus and Ixodes rangtangensis. Comparison between Chinese strains of spirochetes from ticks and American strain B31 in Ultrastructure, monoclonal antibodies reaction and outer surface protein profile revealed certain differences.

Some factors affecting sister-chromatid differentiation (SCD) and sister-chromatid exchange (SCE) in Hordeum vulgare

A study of some factors affecting sister-chromatid differentiation (SCD) and sister-chromatid exchanges (SCE) in Hordeum vulgare is reported. After we studied the influence of 5-fluorodeoxyuridine (FdU) and growth temperature on SCE in barley cells, and the effect of FdU, growth temperature, the growth time of plant cells in 5-bromo-2-deoxyuridine (BrdU) solution on SCD, we found an experimental condition under which the frequency of SCE is lower, but the percentage of SCD is higher. Our data show that ascorbic acid, mitomycin C, adriamycin, and maleic hydrazide induce SCEs in cells of Hordeum vulgare by means of free radicals. This can be shown from the two observations: (1) sulfhydryl compounds such as cysteine and glutathione can completely or partially inhibit the SCEs induced by ascorbic acid, mitomycin C, adriamycin and maleic hydrazide; (2) the amounts of free radicals in root tips correlate with the frequencies of SCE in root tip cells.

Effects of amino acids on sister-chromatid exchanges

The effects of 10 amino acids on sister-chromatid exchange (SCE) frequency in human peripheral blood lymphocytes (PBL) and six amino acids on the SCE frequency in root tip cells of Hordeum vulgare were studied. Alanine (Ala), glycine (Gly), phenylalanine (Phe), valine (Val), histidine (His) and serine (Ser) induced a significant increase in SCE in PBL but threonine (Thr), isoleucine (Ile), lysine (Lys) and arginine (Arg) did not. Ala, Gly, Thr, Ile and Val induced a significant increase in SCE in root tip cells of Hordeum vulgare but Lys did not. The effect of Lys and bromodeoxyuridine (BrdU) on SCE levels in PBL and the interaction between them were also studied. The results show that Lys can inhibit the SCE induced by BrdU.

A conformational rearrangement in gramicidin A: from a double-stranded left-handed to a single-stranded right-handed helix

A conformational transition is described for the polypeptide, gramicidin A, in which a dimer that forms a left-handed intertwined antiparallel helix is converted to a single-stranded amino terminus to amino terminus right-handed helix. The starting structure is determined here by solution NMR methods while reference is made to the well-established folding motif of gramicidin in a lipid bilayer for the ultimate conformation of this transition. Furthermore, an organic solvent system of benzene and ethanol in which gramicidin has a unique conformation is identified. This conformation is shown to be very similar to that derived from X-ray diffraction of crystals prepared from a similar solvent system.

Functional implication of disulfide bond, Cys250 -Cys283, in bovine chymosin

The reduction, carboxymethylation and mercuration of disulfide bond, Cys250-Cys283, located on the surface of bovine chymosin molecule resulted in the loss of about 25% of enzyme activity, suggesting that Cys250-Cys283 is not intimately involved in catalytic mechanism. Cys250 and Cys283 were substituted with Asp. and Ser. by site- directed mutagenesis of the structural gene coding for bovine prochymosin B. All three mutants (C250D/C283S, C250D, C283S) failed to be activated to chymosin in acid, indicating that Cys250-Cys283 might have some contribution to the correct refolding of the unfolded prochymosin.

[Epidemiological survey of hypertension in the remarried families]

In order to inquire into the relative importance of the genetic and the environmental factors in the hypertension, we made generally survey of 484 remarried families in Tangshan. We made comparison for the prevalence rate of hypertension of the familial members whose blood relationship is not the same. The results of research suggest that the effect of genetic factors is relatively more important than the environmental factors in the familial aggregation of blood pressure.

PCR cloning of the cDNA of rabbit skeletal muscle protein phosphatase inhibitor-2

The coding region of the cDNA of protein phosphatase inhibitor-2 was determined by polymerase chain reaction amplification. The cDNA clone consisted of 621 nucleotides, and encoded 204 amino acids. The deduced amino-acid sequence was identical with that of the sequence reported by chemical sequencing methods.

Cell-type specific responses in prostaglandin secretion by glandular and stromal cells from pig endometrium treated with catecholestrogens, methoxyestrogens and progesterone

The pig conceptus and endometrium possess the ability to convert estrogens into catecholestrogens and catecholestrogens into methoxyestrogens. Experiments were carried out to evaluate the effect of catecholestrogens, methoxyestrogens and progesterone on the secretion of prostaglandin (PG) E and F2 alpha by porcine endometrial glandular and stromal cells in vitro. Both 2-hydroxyestradiol (2-OH-E2, 0-20 microM) and 4-hydroxyestradiol (4-OH-E2, 0-20 microM) increased (P less than .05) PGE and PGF2 alpha secretion by stromal cells in a dose response manner. Two-hydroxyestradiol tended (P less than .1) to decrease PGF2 alpha production by glandular cells. Two-methoxyestradiol (20 microM) suppressed (P less than .05) PGF2 alpha secretion by glandular and stromal cells. Four-methoxyestradiol (20 microM) stimulated (P less than .05) PGE production and PGE:PGF2 alpha ratio. Progesterone (.1 microM) suppressed (P less than .05) PG secretion in both cell types. We conclude that catecholestrogens, methoxyestrogens, and progesterone may participate in the establishment of pregnancy by modulating PG production in the endometrium.

Production, purification and characterization of recombinant human interferon gamma

An essentially three-step chromatographic purification procedure, i.e., ion-exchange, immobilized metal ion affinity and size-exclusion chromatography, is described for the purification to homogeneity of recombinant human interferon-gamma (rhIFN-gamma) from the inclusion bodies produced in genetically transformed Escherichia coli cells. Batchwise adsorption of the cloudy solution of renatured rhIFN-gamma obviated the need for high-speed centrifugation to clarify the suspension. This step effectively removed about 70% of extraneous protein impurities. The established purification process is reproducible and leads to a total recovery of 32%. Pilot-scale processing of E. coli cells grown in a 30-l fermentor gave about 70 mg of a homogeneous preparation of rhIFN-gamma. The specific biological activity of purified rhIFN-gamma is ca. 3.4 x 10(7) I.U./mg protein, which is comparable to that of its natural counterpart. It is basic protein (pI greater than pH 9) with a monomer relative molecular mass of 15,000. It behaves, however, as a dimer on size-exclusion chromatography. Its partial NH2-terminal sequence is identical with that established for the rhIFN-gamma. However, its amino acid composition and its relative molecular mass (15,067 as determined by electrospray mass spectrometry) indicate that the purified protein is a truncated form lacking fifteen amino acid residues from its carboxyl-terminal side. This modification does not seem to have any adverse effect on its biological potency. The levels of DNA, bacterial endotoxins and Ni(II) ions in the final product were determined.

Use of radiation with or without WR-2721 in advanced rectal cancer

One hundred patients with inoperable, unresectable, or recurrent adenocarcinoma of the rectum were stratified and randomized to WR-2721 plus radiation therapy (WR + RT) or radiation therapy (RT) only treatment arms. The protector, WR-2721, was administered at a dose of 340 mg/m2 15 minutes before RT, 4 days a week for 5 weeks. The entire pelvis received 225 cGy per fraction for a total of 4500 cGy. The RT only group received the same treatment schedule. After this, both groups received a conedown of 720 cGy in 4 fractions. Inoperable and unresectable cases received a second conedown of 720 cGy. No moderate or severe pelvic normal tissue late effects were seen in the 34 evaluable patients in the combination group. However, in the RT only group, 5 of 37 evaluable patients exhibited late effects of moderate or severe degree. This difference was statistically significant (P = 0.03). There was no evidence of tumor protection by WR-2721. Sixteen percent of patients randomized to the WR + RT group had a complete response compared with 10% in the RT only group. The conditions of 12 patients of 100 became operable and 8 were resected. Seven of these patients remain free of recurrence.

Regulation of usage of membrane and secreted 3' termini of alpha mRNA differs from mu mRNA

Previous studies demonstrated that the addition of transforming growth factor-beta (TGF-beta) to LPS-stimulated B cell cultures induced cells to express membrane IgA and to mature to IgA-secreting cells without a parallel change in usage of 3' termini by alpha mRNA. In these cultures, the secreted form of alpha mRNA was predominant even before expression of membrane IgA could be detected. In the present study, we demonstrate that the preferential usage of the secreted terminus of alpha mRNA in these cultures is not caused by transcription termination and reflects a difference in the regulation of choice of 3' terminus for alpha and mu mRNA. The addition of TGF-beta to LPS-stimulated cultures causes an increase in the steady state level of alpha mRNA using the secreted 3' terminus. In contrast, TGF-beta decreases the steady state level of mu mRNA and inhibits usage of the 3' terminus for the secreted form of mu, suggesting that the choice of 3' terminus for alpha and mu mRNA is regulated differently in LPS-stimulated cultures. To determine whether the difference in usage of 3' termini by alpha and mu mRNA was a property of the culture system or whether it reflected a difference in regulation, C alpha was transfected into cell lines representing different stages of B cell development. The secreted form of alpha mRNA predominates regardless of the ratio of membrane to secreted forms of the endogenous C mu gene. A similar dichotomy in 3' terminus usage occurred in a stable C alpha transfectant of the BCL1 lymphoma, suggesting that trans-acting factors are not limiting. Furthermore, as was the case with normal B cells, the predominance of the secreted form of the transfected C alpha genes was not due to transcription termination. These data demonstrate that usage of 3' terminus in alpha and mu mRNA is regulated differently.

Regulation of usage of membrane and secreted 3' termini of alpha mRNA differs from mu mRNA

Previous studies demonstrated that the addition of transforming growth factor-beta (TGF-beta) to LPS-stimulated B cell cultures induced cells to express membrane IgA and to mature to IgA-secreting cells without a parallel change in usage of 3' termini by alpha mRNA. In these cultures, the secreted form of alpha mRNA was predominant even before expression of membrane IgA could be detected. In the present study, we demonstrate that the preferential usage of the secreted terminus of alpha mRNA in these cultures is not caused by transcription termination and reflects a difference in the regulation of choice of 3' terminus for alpha and mu mRNA. The addition of TGF-beta to LPS-stimulated cultures causes an increase in the steady state level of alpha mRNA using the secreted 3' terminus. In contrast, TGF-beta decreases the steady state level of mu mRNA and inhibits usage of the 3' terminus for the secreted form of mu, suggesting that the choice of 3' terminus for alpha and mu mRNA is regulated differently in LPS-stimulated cultures. To determine whether the difference in usage of 3' termini by alpha and mu mRNA was a property of the culture system or whether it reflected a difference in regulation, C alpha was transfected into cell lines representing different stages of B cell development. The secreted form of alpha mRNA predominates regardless of the ratio of membrane to secreted forms of the endogenous C mu gene. A similar dichotomy in 3' terminus usage occurred in a stable C alpha transfectant of the BCL1 lymphoma, suggesting that trans-acting factors are not limiting. Furthermore, as was the case with normal B cells, the predominance of the secreted form of the transfected C alpha genes was not due to transcription termination. These data demonstrate that usage of 3' terminus in alpha and mu mRNA is regulated differently.

[Effect of mieyanling oral liquid on the immune responses in normal and cyclophosphamide treated mice]

It has been proved that Mieyanling in Vivo and in Vitro, can augment the lymphocyte transformation rate induced by PHA, Con-A or LPS in mice. The suppressed immune function caused by cyclophosphamide can also be significantly relieved by Mieyanling Oral Liquid.

Effect of microvascular rarefaction on tissue oxygen delivery in hypertension

A mathematical model of oxygen transport in tissue was used to analyze the effects of microvessel rarefaction and nonhomogeneous oxygen consumption on tissue oxygen distribution. The model was based on the diffusion equation with a nonhomogeneous consumption term. Solutions were computed for several configurations of vessel and oxygen sink distributions on a finite domain using the finite element method. A microcirculatory unit consisting of a tissue slice of 100-microns depth and 40-microns width was chosen. Symmetry boundary conditions were applied so that the entire tissue consisted of a series of such microvascular units placed side by side. The boundary condition at the surface of the unit was chosen to simulate a tissue suffusion experiment in which the suffusion oxygen was varied from 0 to 37 mmHg. Results of the model, which were compared with direct measurements with oxygen microelectrodes, indicate that vascular oxygen delivery strongly dominates the tissue oxygen field for suffusion PO2 values of less than 20 mmHg, whereas above this level tissue oxygen is dominated by the suffusion PO2. Reduction of vessel density within the tissue was found to have the largest effect on tissue oxygen levels at low suffusion oxygen. Finally, under some configurations of oxygen sources (vessels) and sinks (mitochondria), extremely low PO2 levels may exist within the area of high consumption, which could limit the metabolic activity of the tissue.

Relationship of saccular ultrastructure to otolith growth in the teleost Oreochromis niloticus

The sacculus of Oreochromis niloticus is anatomically separated from the utriculus and semicircular canals. The saccular wall is composed of the sensory epithelium, transitional epithelia, and squamous epithelium. Cellular granules are abundant in the sensory and transitional epithelia but scarce in the squamous epithelium. Over the dorsal side of the dorsal transitional epithelium there exists an oval patch of cells with distinctive microvilli. New finding is a shallow groove which extends from the anterior end of the sensory epithelium approximately halfway down along the ventral perimacular transitional epithelium. Small vesicles, which appear "empty" under transmission electron microscopy (TEM), are aggregated in the posterior region of the groove. These small vesicles are also present in both the sensory and transitional epithelia. A second kind of vesicle is comparatively large and appears filled with stainable contents. These vesicles are restricted to the sensory region. Both kinds of vesicles appear to be involved in apical secretion and possibly provide the otolithic membrane with fibers. The otolithic membrane is composed of a gelatinuous layer and subcupular meshwork. The meshwork appears to contribute to the formation of the otolith. The small empty vesicles appear to originate in sensory and transitional epithelial cells and may form the subcupular meshwork. The larger filled vesicles are derived predominantly from sensory cells in the sensory epithelium and appear to contribute to the gelatinuous layer of otoliths. © 1992 Wiley-Liss, Inc.

Uptake and metabolism of N-(4'-pyridoxyl)amines by isolated rat liver cells

Uptake and metabolism of [3H]pyridoxine and 3H-labeled N-(4'-pyridoxyl)amines by isolated rat liver cells were studied at physiological concentration (0.5 microM) of vitamin B6 by using both membrane filtration and centrifugation methods for removal of radiolabeled solutes after incubations with cells. It was found that the characteristics of import of N-(4'-pyridoxyl)amines into liver cells is similar to those of import of natural vitamin B6. Upon entry each 4'(N)-substituted pyridoxamine was converted to its 5'-phosphate and then oxidized to release pyridoxal 5'-phosphate and the original amine. Considerable size of the amine substituent is tolerated for transport and metabolism, but a charged function impedes entry. The amount of released pyridoxal 5'-phosphate (and therefore the amount of released original amine) is controlled partially by the size of the amine affixed to B6 and partially by the enzymatic steps involved. This system illustrates how biologically active amines can be piggybacked onto a vitamin that gains facilitated entry to cells that have the enzymatic means to release the free amine for subsequent effects within the cell.

Epidermal growth factor receptors in porcine endometrium: binding characteristics and the regulation of prostaglandin E and F2 alpha production

Epidermal growth factor (EGF) and its receptor have been implicated in the control of uterine cell growth and differentiation. The objectives of this study were to determine EGF binding characteristics and effects of EGF on prostaglandin (PG) production in vitro by glandular and stromal cells from porcine endometrium. Endometrial tissues were taken from 10 sows on Day 13 of pregnancy (first day of estrus = Day 0). Glandular and stromal cells were separated by enzymatic dispersion and sieve filtration and cultured for 3 days. EGF-binding assay was carried out at 20 degrees C in the presence of 0.2 nM 125I-EGF with increasing concentrations of unlabeled EGF (0-12 nM). Scatchard analyses revealed one class of high-affinity binding sites in each cell type with apparent equilibrium dissociation constants (n = 6) of 2.96 +/- 0.60 nM and 2.48 +/- 0.50 nM for stromal and glandular cells, respectively. The apparent binding capacities were 199.3 +/- 34.8 fmol/10(6) cells for stromal cells and 40.7 +/- 6.5 fmol/10(6) cells for glandular cells. Effects of EGF on PG production were determined by including 1, 5, 10, or 20 ng/ml EGF in the medium for the final 24 h of the 72-h culture. EGF increased PGE (p less than 0.01) and PGF2 alpha (p less than 0.05) secretion by stromal cells. The highest concentration (20 ng/ml) of EGF increased secretion of PGE and PGF2 alpha by 133% and 64%, respectively, over controls.(ABSTRACT TRUNCATED AT 250 WORDS)

[Detection of serum antibody against hepatitis C virus in patients with hepatitis and liver diseases]

Antibody against hepatitis C virus (anti-HCV) was tested in 658 cases of hepatitis and liver diseases with ELISA, ninety of these cases were positive, with a total infection rate of 13.68% (90/658). The positive rate of anti-HCV was highest in patients with chronic severe hepatitis (33.78%) and CAH accompanied by cirrhosis of liver(31.58%). The infection rate in other types of hepatic diseases in order of frequency was as follows: fulminant hepatitis (18.18%), CAH without cirrhosis (15.13%), subacute severe hepatitis (13.43%), CPH (5.88%), primary hepatocellular carcinoma (3.85%), and acute hepatitis (2.42%). Serological markers of HBV infection were detectable concomitantly in 77 of the 90 cases who were anti-HCV positive, but there was no evidence of mutual inhibition of viral replication. There was neither appreciable difference in the level of hyperbilirubinemia in cases of hepatitis with or without anti-HCV, nor significant diversity in the number of death between cases of severe hepatitis with and without anti-HCV.

Distribution of PGM1 subtypes in 12 populations of China

The distribution of PGM1 subtypes in 12 populations of China was studied by using isoelectric focusing (IEF) in 0.5 mm thick polyacrylamide gel, pH 5-7. It was found that the PGM1*1A frequency was higher in northern China and lower in the south. Phosphoglucomutase (PGM: E. C. 2. 7. 5. 1) occurs in all human tissues and is controlled by four autosomal loci, i.e., PGM1, PGM2, PGM3 [Hopkinson and Harris 1968] and PGM4 [Cantu and Ibarra 1982]. The Polymorphism at the PGM1 locus in human was first revealed in 1964 [Spencer et al 1964]. Since then, extensive studies showed that two codominant alleles, PGM1*1 and PGM1*2, are present on locus PGM1 in all populations, as well as many rare alleles. Investigations with isoelectric focusing (IEF) revealed the presence of four common allotypes, which were previously labelled as PGM1*1+, PGM*1-, PGM*2+, PGMI*2- [Bark et al 1976]. The workshop, held in West Germany in 1985, recommended a new nomenclature: PGM1*1A, PGM1*1B, PGM1*2A and PGM1*2B instead of PGM*1+, PGM1*1-, PGM1*2+ and PGM1*2- in order to avoid misunderstanding [Dykes et al 1985]. A large body of data on the distribution of the four common PGM1 alleles in different populations in the world has been accumulated. But the data on PGM1 in China are yet very limited. The present paper reports the PGM1 gene frequencies in 8 national minorities and 4 subpopulations of Han in China.

Potential 67Ga radiopharmaceuticals for myocardial imaging: tris(1-aryl-3-hydroxy-2-methyl-4-pyridinonato)gallium(III) complexes

A series of highly lipophilic complexes of 1-aryl-3-hydroxy-2-methyl-4-pyridinones with gallium(III)-67 has been evaluated in vitro and in vivo as potential radiopharmaceuticals. The pyridinones have different substituents at the para-position of the phenyl ring: R = H, CH3, OCH3 and NO2. Biodistribution studies of 67Ga complexes have been carried out in rabbits, mice, rats and a dog. High heart uptake of the radionuclide has been shown in rabbits and the dog. The different biodistribution patterns in mice and rats indicate that there is a species difference in the biodistribution of these complexes. Rabbits and the dog show rapid heart uptake and blood clearance. The speciation of the Ga3+ ion in vivo is simulated in vitro with a simple blood plasma model based on the available thermodynamic data.

The quality of family planning services in rural China

This article provides a preliminary analysis of three aspects of service quality in four rural counties in China--the availability of contraceptive methods, information given to users, and provider knowledge about methods. Contraceptive choice and characteristics of contraceptive use by women in the study areas are also examined. The data are derived from a survey carried out by the authors during 1987, under the auspices of China's State Family Planning Commission. The survey was conducted in four rural counties located in Fujian and Heilongjiang provinces. A total of 318 married women of reproductive age were randomly selected and interviewed. All family planning service sites serving the women were visited and a sample of service providers was interviewed. No shortage of contraceptives existed in any of the counties, but variations in community wealth and local procurement practices have resulted in the acquisition of an IUD with high failure rates. Although providers believe they inform women about method choices and side effects, women were poorly informed about the methods they selected. Not all providers who insert IUDs and distribute pills were knowledgeable about contraindications and side effects of the methods. Ever-use of contraception was nearly 100 percent, but most women, especially in Heilongjiang, have only used one method: the IUD or sterilization. Improvements in quality, especially in method mix, providers' level of knowledge, and the quality and quantity of information provided to users will likely improve contraceptive continuation, client satisfaction, and women's health.

Ultrastructure of otolith increments and checks in the teleost fish Oreochromis niloticus

An otolith increment is composed of an incremental zone and a discontinous zone. Observation of the otoliths of Oreochromis niloticus with transmission and scanning electron microscopy reveals that organic fibers are concentrated in the discontinuous zone and are relatively scarce in the incremental zone. On the other hand, calcium carbonate crystals are chiefly packed in the incremental zone and are less dense in the discontinuous zone. Both fibers and crystals are oriented perpendicular to the growth increments. Otolith checks, or discontinuities, contain even denser fibers and fewer fine crystals than does the discontinuous zone. A higher proportion of individual fibers is prominently stained in the discontinuous zone and check than in the incremental zone. Other features of individual fibers appear to be the same among the three zones. The crystals on either side of a check or a discontinuous zone resemble each other both in size and orientation. Zonation of protein and mineral components of otoliths can be understood in terms of both incremental growth and the daily cycle of deposition.

Effects of recombinant cytokines on murine megakaryocyte colony formation in a serum-free fibrin clot culture system

A convenient serum-free fibrin clot culture system for murine megakaryocyte progenitor cells was developed. The culture and counting of colonies is much easier in this system, when compared with previously reported serum-free culture methods. Recombinant murine interleukin-3 (rmIL-3) stimulated megakaryocyte colony formation in a dose-dependent manner in this system. While recombinant human granulocyte colony-stimulating factor (rhG-CSF) had no effect on megakaryocytopoiesis, recombinant human erythropoietin (rhEpo) and recombinant human interleukin-6 (rhIL-6) augmented megakaryocyte colony formation stimulated by rmIL-3. The depletion of adherent cells and T cells from the cultured bone marrow did not eliminate the synergistic effect of rhEpo and rhIL-6.

Interim analysis of a randomized trial of radiation therapy of rectal cancer with/without WR-2721

The objectives of this randomized trial are to define the maximum tolerated dose of radiation therapy, at curative dose levels, that can be delivered following WR-2721, and to observe the anti-tumor effects and normal tissue responses. One hundred patients with inoperable, unresectable, or recurrent rectal cancer were stratified and randomized to radiation only, or WR-2721 and radiation. The entire pelvis is treated with 4 portals 4 times a week to a total of 4500 cGy (first level dose) in 5 weeks. WR-2721, 340 mg/m2 was given 15 minutes before radiation to the combination group. Subsequently, both groups received a conedown of 720 cGy in 4 days to 144(2) cm portals APPA, and if originally inoperable or unresectable 720 cGy in four days to second conedown of 64(2) cm. Patients were observed from 3 to 18 months (median = 12 months). No significant hypotension or hematologic toxicity occurred in the WR-2721 treated group. Mild to moderate emesis occurred in 80% of the courses. (No antiemetics were used.) Moderate or severe acute toxicities to normal tissues were observed less frequently in the WR-2721 arm. No moderate or severe late toxicities to the skin, mucous membrane, urinary bladder or intestine was observed in the WR-2721 group, however, 5 patients treated with radiation alone experienced moderate or severe late toxicity to these organs. No evidence of tumor protection was observed.

[Atmosphere pollution by sulfur dioxide during processing of zirantong]

This paper reports the colorimetric determination of total SO2 in Zirantong by the method of rosaniline hydrochlorid. Samper of processed Zirantong from the pharmacy have been analyzed and the quality specifications established. Optimum conditions for processing have been chosen and a procedure has been proposed for the recovery of the poisonous matter SO2 which is then transformed into a beneficial material.

Surgical technique for combined liver/intestine transplantation in rats

Simultaneous liver transplantation may reduce the risk of intestinal transplant rejection. We have recently developed two new models of combined liver/intestine transplantation (LIT) in the rat to study this phenomenon. Herein, we report our experience with LIT using a single donor (SD) or multiple donors (MD). Large volumes of fluid were required to prevent a drop in the mean arterial pressure during the anhepatic phase in the SD recipients. Many of the SD recipients died of intraoperative hypovolemic shock (57%). The MD recipients had a shorter anhepatic time (12 +/- 1 minutes vs. 17 +/- 2 minutes; P less than 0.01) and a shorter warm intestinal ischemia time (15 +/- 1 minutes vs. 32 +/- 2 minutes; P less than 0.01). Operative mortality rates were much lower in the MD recipients (10% vs. 68%; P less than 0.01). The long-term survival rate using MD was 71% at 1 month. Graft function was normal in the long-term survivors. LIT with MD provides a good model to study the immunological effects of multivisceral grafting.

Molecular basis of inherited medium-chain acyl-CoA dehydrogenase deficiency causing sudden child death

Deficiency of medium-chain acyl-CoA dehydrogenase (MCAD) is an important cause of sudden death in children. The majority of surviving individuals with MCAD deficiency studied to date are homozygous for a single point mutation at bp 985 of the MCAD mRNA (A985G). We have now identified a four-base-pair deletion in exon 11 of one allele of the MCAD gene in an American child who died of MCAD deficiency. The deletion mutation results in a frameshift and premature termination codon in the mutant MCAD mRNA. The second mutant allele contained the common point mutation A985G, and thus the proband was a compound heterozygote. Protein immunoblot analysis of the child's liver proteins revealed that the mutant MCAD proteins were barely detectable. Allele-specific oligonucleotide hybridization analysis performed on amplified exon 11 of the child's MCAD gene clearly identified both mutations. MCAD RFLP analysis of the patient's DNA revealed heterozygosity at the Taq I MCAD RFLP site, thus, the two mutations are associated with different haplotypes. Therefore, we have identified a new mutation in the MCAD gene and have developed a nucleic-acid-based screening approach which allows the post mortem identification of MCAD deficiency.