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Despite potential differences in the mechanism and potency of toxicity between the two common oxidation states of arsenic (As(III) and As(V)), assessments of the risk from inhaled arsenic generally ignore the oxidation state of inorganic arsenicals. Differences between potency and toxicity of As(III) and As(V) were evaluated by determining alteration in function of pulmonary alveolar macrophages (PAM) following in vivo and in vitro exposure to soluble arsenic. Male Sprague-Dawley rats were used throughout. One day following intratracheal instillation of 1 mg/ml (as arsenic) of either sodium arsenite (As(III)) or sodium arsenate (As(V)), PAM were lavaged and analyzed for alterations in superoxide (O2-), prostaglandin E2 (PGE2), and tumor necrosis factor (TNF-alpha) production. There were no differences in bronchoalveolar lavage fluid PGE2 or TNF-alpha. PAM lavaged from As(V)-exposed animals showed significant increases in O2- production. In vivo exposure to either oxidative form of arsenic decreased basal and lipopolysaccharide (LPS)-induced release of TNF-alpha production by PAM, but did not suppress LPS-induced production of PGE2. To test the direct effects of arsenic on PAM function, PAM were lavaged from control animals and exposed, in vitro, to either arsenical for up to 24 hr to concentrations of 0.1 to 300 micrograms/ml arsenic. Doses used were not cytotoxic to PAM, since LDH release was not significantly increased, even at the highest dose. Significant dose-dependent inhibition of O2- production was only evident after 24 hr exposure to arsenicals. As(III) was more potent than As(V), inhibiting O2- at concentrations as low as 0.1 micrograms/ml compared to 1.0 micrograms/ml of As(V). Suppression of LPS-induced release of TNF-alpha also occurred at lower concentrations of As(III), 50% inhibition at 0.15 micrograms/ml, compared to As(V), 50% inhibition at 1.8 micrograms/ml. While As(III) exposure had no affect on PGE2 production, As(V) caused inhibition of LPS-induced PGE2 production at concentrations above 1.0 micrograms/ml. Differences between As(III) and As(V) indicate that different mechanisms and/or potencies exist between the two arsenic species. Arsenic-induced alteration in PAM function may compromise host defense against infections and alter immune surveillance.

Intravenous heroin abusers suffer a great variety of infections, including AIDS (acquired immune deficiency syndrome). We developed an experimental mouse model to evaluate the long-term effect of in vivo morphine administration during retrovirus-induced immune dysfunction. Mice were treated daily for 11 weeks with increasing doses of morphine. Morphine treatment produced a decrease in body weight and spleen cell number. Murine retrovirus infection provoked an increase in body weight due to enlargement of lymphoid organs, and an increase in the percentage and absolute number of CD4+ and Mac 1+ cells. Interestingly, retrovirus-infected mice that were also morphine-treated did not show the increase in the relative proportion of Mac 1+ cells. Moreover, under the experimental conditions of protein-malnutrition and morphine treatment potentiation of immune dysfunction by murine retrovirus infection was investigated. Retrovirus infection-induced splenocyte proliferation was partially regulated by morphine treatment. Splenocytes from retrovirus-infected mice presented a higher percentage of IL-2R+ cells and, lower levels of sIL-2R in splenocyte supernatants. Mitogen-stimulated splenocytes had a lower production of interferon-gamma as well as an increase in the secretion of tumor necrosis factor-alpha. Thus morphine altered the immune system by down-regulating splenocyte proliferation, because retrovirus infection-induced splenocyte proliferation was partially regulated by morphine treatment. We also evaluated the effects of joint murine retrovirus infection and protein undernutrition on the thymus cell subsets. Retrovirus infection was associated with a decrease in the absolute number of Thy 1+, CD4+ and CD8+ cells per thymus with the CD8+ cell subset being the most affected. Moreover, retrovirus-infected mice presented a dramatic decrease in the percentage of double-positive (CD4+ CD8+) cells in the thymus as well as changes in its immunoarchitecture. While protein undernutrition alone did not produce further differences between infected versus non-infected, protein-undernourished, morphine treatment induced a greater decrease in thymocyte number than that seen in retrovirus- or morphine-treated animals alone.

Severe infections in intravenous drug abusers could be the consequence of morphine-induced damage on the immune system. To evaluate the long-term effect of in vivo morphine administration on the immune system we developed an experimental model where we studied the combined effects of morphine treatment and protein malnutrition. We treated protein-undernourished mice daily for 11 weeks with increasing doses of morphine. Morphine treatment produced a decrease in body weight and spleen cell number. The changes observed were partially independent of the nutritional status of the host. Saline-injected mice showed a decrease in the percentage of Thy 1+ cells in the spleen. Morphine treatment induced a decrease in the total number of cells and therefore in the absolute number of T-(Thy 1, CD4, CD8), B- and Mac 1+ (macrophages) cells in protein-undernourished mice. Saline-injected mice showed a decrease in the percentage of Thy 1+ cells and an increase in the percentage of B- and Ia(+)-cells in the spleen. We conclude that morphine altered the immune system by down-regulating splenocyte proliferation. We also studied the effects of i.p. administered morphine on expression of thymocyte phenotype in well-nourished and protein-undernourished mice. In well-nourished mice, morphine treatment reduced the number of Thy 1+, CD4+ and CD8+ cells per thymus to 30% of that found in untreated mice and to 40% of the cells in those saline-treated controls.(ABSTRACT TRUNCATED AT 250 WORDS)

This study deals with the antiulcer effect of water extract and ether extract of Cinnamomum cassia on four types of experimental gastric ulcer and with the antidiarrhea effect on two types of medicine-induced diarrhea in mice. These extracts have choleretic effect in anesthetized rats, and are analgesic as well. This is the pharmacologic basis of spleen-stomach warming and analgesic action of Cinnamomum cassia.

Use of cocaine concurrently with alcohol is prevalent among cocaine addicts. Cocaine has been shown previously to inhibit phytohemagglutinin- and ConA-induced proliferation of T-lymphocytes, NK cell cytotoxicity and phagocytic activity of peritoneal macrophages. We compared the immunotoxic effect of cocaine, combination of cocaine with ethanol, or cocaethylene, a derivative formed from cocaine and ethanol in the body, on the mitogen-stimulated production of cytokines by splenocytes. C57B1 mice were injected twice daily with 20 mg/kg cocaine or equivalent dose of cocaethylene and received a liquid Lieber-DeCarli diet containing ethanol (26% of total calories) or isocaloric amount of maltose-dextrin. After 4 weeks of treatment cocaine and cocaethylene caused a significant decrease of the spleen weight and total number of splenocytes. In splenocytes isolated from the cocaine- or cocaethylene-treated mice mitogen-stimulated production of gamma-interferon, tumor necrosis factor, and interleukin-2 was suppressed, in all cases more severely when cocaethylene was used. Thus formation of cocaethylene during simultaneous consumption of cocaine and ethanol may enhance the immunotoxicity of cocaine.

Archival autopsy studies of sickle cell disease have often been hampered by inadequate documentation of the genotype. Although the polymerase chain reaction (PCR) has been applied to the prenatal diagnosis of sickle cell disease, its use has not been reported in archival studies of sickle cell disease. In this study, DNAs from formalin-fixed, paraffin-embedded archival tissues were amplified by PCR and analyzed by dot-blot hybridization using allele-specific oligonucleotides. These S and C genotypes for 9 of 10 archival specimens studied blindly were correctly identified by PCR. The tenth specimen consistently failed to amplify by PCR, yielding no result. These data demonstrate the utility of PCR for retrospective identification of the genotype of sickle cell disease. This application of PCR will significantly expand the number of autopsy cases suitable for retrospective studies of the morbidity and mortality of sickle cell disease.

We studied the effects of D-factor on the growth of leukemic blast progenitors from 15 patients with acute myeloblastic leukemia and two leukemia cell lines in methylcellulose and suspension cultures. When stimulated by granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor or interleukin-3, leukemic blast progenitors undergo terminal division with limited differentiation in methylcellulose culture, forming blast colonies. Leukemic blast progenitors can renew themselves. The self-renewal can be detected as secondary colony formation after replating primary blast colonies in fresh methylcellulose media and by the growth of clonogenic cells in suspension culture. D-Factor suppressed primary and secondary colony formation in methylcellulose culture. Furthermore, D-factor suppressed clonogenic cell recovery in suspension culture. The suppression by D-factor of the growth of leukemic blast progenitors was not significantly dependent upon the colony-stimulating factors used as growth-stimulating factors. High concentration of G-CSF did not overcome the suppressive effect of D-factor. The results indicate that D-factor is effective in suppressing not only terminal division but also self-renewal of leukemic blast progenitors.

We have developed an experimental mouse model to study the effect of daily cocaine administration on the immune system during an acquired immune deficiency syndrome (AIDS). Mice were infected with LP-BM5 murine leukemia virus, a retrovirus which causes immunosuppression with the development of functional murine AIDS. Increasing doses of cocaine given by daily intraperitoneal injection for 11 weeks reduced body weight. A daily cocaine injection in some mice as well as a saline injection in others showed a decrease in the percentage of Thy 1.2+, CD4+ and CD8+ cells, while both treatments increased the percentage and absolute numbers of B-cells per spleen. Saline and cocaine treatment induced an increase in gamma-IFN and TNF-alpha production by splenocytes. Cocaine treatment favored a decrease in sIL-2R secretion. Saline and cocaine treatment had slightly different effects on the splenocytes of protein-malnourished mice. Cocaine treatment induced an increase in the percentage of CD8+ cells. Saline and cocaine treatments decreased the number of Mac 1+ cells in the spleen. Moreover, saline- and cocaine-treated protein-malnourished mice splenocytes did not present the increase in gamma-IFN production as well-nourished mice splenocytes showed. Retrovirus-infected mice showed a decrease in the percentage of Thy 1.2+ and CD8+ cells and an increase in the percentage and absolute numbers of CD4+, IL-2R+, Mac 1+ and B-cells. Cocaine partially prevented the enlargement of lymphoid organs due to lymphoid cell proliferation induced by murine retrovirus infection, but had little effect on the elevated percentage of CD4+ cells or B-cells or the depressed numbers of CD8+ cells associated with virus infection. However, cocaine did reduce the number of activated IL-2R+ cells and macrophages (Mac 1+) in addition to reducing the total number of cells per spleen in all subsets in retrovirus-infected mice, but not in uninfected controls. Cocaine treatment and retrovirus infection alone or in combination suppressed the release of sIL-2R into supernatant fluid during in vitro culture of splenocytes. These data illustrate that cocaine treatment modulates cell proliferation in retrovirus-infected mice and thus modifies the absolute number of cells in those subsets already altered by retrovirus infection. Retrovirus-infected and retrovirus-infected cocaine-treated protein-malnourished mice showed similar results.

The in vitro growth activities and drug sensitivities of leukemic blast progenitors were compared among the subgroups of acute myelocytic leukemia (AML) classified according to the French-American-British (FAB) cooperative group. Leukemic cells separated from the peripheral bloods of AML patients were cultured in methylcellulose media, and the plating efficiencies of primary colonies (PE1) and secondary colonies after replating (PE2) were determined. PE1 and PE2 have been considered to reflect the capacities of terminal divisions and self-renewal of leukemic blast progenitors, respectively. PE1 and PE2 were variable among AML patients; these findings suggest that AML is a heterogeneous disease in terms of the proliferative activities of leukemic cells. No significant correlation was noted between PE1 or PE2 and the AML subtype. The sensitivities to cytosine arabinoside (Ara-C) of leukemic blast progenitors were studied in methylcellulose and suspension cultures. Ara-C sensitivity was not significantly correlated with the AML subtype, either. In contrast, there was statistically significant correlation between PE2 and the remission outcome of the patients, whereas PE1 was not significantly associated with the clinical outcome. The results in the present study indicate that the proliferative activity, especially self-renewal capacity, of leukemic blast progenitors is highly predictive of the prognosis of AML patients but is not significantly correlated with the AML subtype classified by the blast morphology.

Previously, we demonstrated that production of gamma-interferon (gamma-IFN) by the mouse splenocytes isolated at night was higher than from those isolated in the morning. In this paper we show that melatonin increased gamma-IFN production by murine splenocytes. Moreover, this stimulating effect was significantly higher (10 times) in the cells isolated at night than in those isolated in the morning (2 times).

Alveolar macrophages (Am phi s), resident peritoneal macrophages (RPm phi s), and thioglycolate-elicited peritoneal macrophages (TGPm phi s) were isolated from C57BL/6 mice and incubated with lipopolysaccharide (LPS), stimulated cell supernatant, or recombinant interferon gamma (IFN-gamma) for 24 h. Tumor necrosis factor (TNF) in cell-free supernatants was measured by enzyme-linked immunosorbent assay. Amo phi s incubated with 10(3) ng/ml LPS produced 50 times more TNF than RPm phi s and 5 times more than TGPm phi s, and LPS alone induced maximum TNF production by Am phi s. Stimulated cell supernatant or recombinant IFN-gamma alone did not induce TNF production. A combination of LPS with stimulated cell supernatant or IFN-gamma had only a limited synergistic effect on TNF production by Am phi s. However, both LPS and stimulated cell supernatant or recombinant IFN-gamma induced maximum TNF production by RPm phi s and TGPm phi s. TGPm phi s showed greater sensitivity to LPS and stimulated cell supernatant or IFN-gamma with regard to TNF production than the other macrophage populations investigated.

Peripheral blood lymphocytes from 47 Hispanic poly-drug users with a history of cocaine abuse were analyzed for in vitro production of interleukin-1 (IL-1), interleukin-2 (IL-2), gamma-interferon (IFN) and plasma levels of soluble IL-2 receptor (SIL-2R). Cocaine use was confirmed and quantified by analysis of hair and urine samples, and subjects were grouped into 3 based on the extent of cocaine metabolites detected. No significant differences in IL-1 and IFN production were seen between the 3 groups. However, subjects with higher levels of cocaine in hair also showed higher levels of IL-2. In addition, a positive correlation was seen between cocaine concentrations and IL-2 levels. A corresponding negative correlation was seen between cocaine levels and levels of plasma SIL-2R. These findings suggest modulation of the IL-2 network by cocaine in poly-drug users.

The actions of retroviral infections, aging, and cocaine and morphine injection on cytokine production were investigated in C57BL/6 female mice. Retroviral infection with LP-BM5 murine leukemia virus was further developed as a model of murine acquired immunodeficiency syndrome (AIDS). The effects of cocaine and morphine on gamma-interferon (IFN) and tumor necrosis factor (TNF) production in vivo and with isolated spleen cells were measured by a sandwich enzyme-linked immunosorbent assay (ELISA) method. Serum IFN was generally not detected in any group except mice injected with saline and young mice infected with LP-BM5 virus. Splenocytes from mice with murine AIDS produced less IFN when stimulated in vitro by ConA. In aged mice, IFN production by spleen cells was severely suppressed by retroviral infection. Cocaine had a tendency to suppress IFN production by stimulated cells in vitro. Morphine tended to reduce IFN production by spleen cells from retrovirally infected animals. The serum TNF level in mice with murine AIDS was elevated creating higher levels in morphine and morphine plus cocaine treated uninfected mice while cocaine injection eliminated serum TNF. When stimulated in vitro by lipopolysaccharides (LPS), splenocytes from mice with murine AIDS also produced more TNF than uninfected controls. TNF production in vitro and in vivo was significantly increased by retroviral infection. Therefore, results indicate that cocaine and retroviral infection modulate TNF and IFN production.

Transgenic mice with ectopic expression of bovine cellular retinoic acid-binding protein (CRABP) under the control of human metallothionein IIA promoter have been generated. From a total of 10 independent transgenic live borns, six lines have expressed the bovine CRABP messages in a variety of tissues. Among the six lines, three appear to be normal and healthy in the founders as well as their offspring, one has generated transgenic offspring with retarded growth and two have produced only female transgenic mice that are all sterile.

A 3233 base pair (bp) sequence of the 5'-flanking region of the mouse cellular retinoic-acid-binding protein (CRABP) gene is determined. From this region, a 3 kb fragment located 150 bp upstream from the transcriptional initiation site is isolated and fused to a LacZ reporter sequence. Transgenic mouse embryos of this fusion gene show spatially and temporally specific expression of LacZ protein and the expression of this fusion gene at the RNA level is confirmed by RNAase protection assays, which detect specific fusion transcripts in RNA samples from tissues of transgenic mouse embryos. In contrast, transgenic mouse embryos of a shorter fusion gene containing only 583 bp from the same upstream region of the mouse CRABP gene fused to the same reporter sequence show no LacZ activities. Thus, it is concluded that the 3 kb sequence, but not the 583 bp sequence, of the mouse CRABP gene contains information for its temporally and spatially specific expression in mouse embryos.

An experimental model which resembles human drug addiction was developed to study the effect of chronic drug (cocaine or morphine) administration on the immune system. As malnutrition has been associated with drug use, a low protein diet has been evaluated for its contribution to the impairment of the immune system during cocaine/morphine addiction. Female C57BL/6 mice that received a 20% or 4% casein diet were studied. Both drugs were administered intraperitoneally daily for 11 weeks and drugs were administered in increasing daily doses, beginning after 3 weeks of diet consumption. Doses of cocaine began with 5 mg/kg body weight and reached the maximum dose of 40 mg/kg/day at the fourth week. Doses of morphine gradually increased from 10 mg/kg to 75 mg/kg body weight with the maximum dose reached after 5 weeks of treatment. Cocaine administration reduced body weight, particularly in the low protein diet group, and spleen weight in protein malnourished mice. Cocaine as well as saline injected mice showed a decrease in the percentage of CD4+ CD8+ and Mac-1+ cells and an increase in B cells in the spleens of well nourished mice. Morphine-treated mice showed similar results to those observed in cocaine or saline treated mice. These results suggest that cocaine, morphine or saline injection can alter the percentage of cells that express a defined phenotype independently of the nutritional status of the subject. Moreover, the effect appears dependent on a stress mediated process.

This paper reports on the regular pattern of growth and decline of the circulating antigen (CA) determined by I-ELISA in experimentally infected rabbits. Toxoplasma antigen was demonstratable in the circulation in 64.7% rabbits 1 day after tachyzoite inoculation and the level of the CA in sera from infected rabbits showed an increase on d4 and reached its peak level on d10-13 after inoculation but declined soon thereafter. CA was not detectable on days 60 to 90 after inoculation. The results suggest that determining CA is a useful means for diagnosing active toxoplasmosis and that I-ELISA might be a promising approach to detect CA in toxoplasmosis.

Pure cultures of monensin-sensitive ruminal bacteria were involved in both the production and utilization of pyro-glutamate (pyrrolidone carboxylic acid), a novel product of glutamine fermentation, but the effect of monensin on pyro-glutamate accumulation in mixed cultures had not been assessed. Mixed ruminal bacteria (n = 3) fermented glutamine (40 mM) at a rapid rate (63 nmol/[mg protein-min]) and there was a transient increase in pyro-glutamate (3 mM). Monensin (5 ppm) decreased the rate of glutamine fermentation 70% and greatly enhanced the conversion of glutamine to pyro-glutamate (50 vs 7%). Glutamate was fermented at nearly the same rate as glutamine, and monensin eliminated glutamate fermentation. Glutamate was never converted to pyro-glutamate. Trypticase, a pancreatic digest of casein, contained pyro-glutamate, and a significant fraction (30%) of its N was never converted to ammonia. Pyro-glutamate utilization was reduced by monensin and low pH (less than 6.0). Based on these in vitro observations, pyro-glutamate could be a significant end-product of glutamine degradation when animals are fed monensin.

The vaccinia virus HindIII D fragment is 16,060 bp in length and encodes 13 complete genes [E.G. Niles et al. (1986). Virology 153, 96-112; S. L. Weinrich and D. E. Hruby (1986). Nucleic Acids Res. 14, 3003-3016]. Six of these genes are expressed only at early times after infection and one gene is expressed at both early and late times [G. -J. Lee-Chen and E. G. Niles (1988). Virology 163, 52-63]. Transcript mapping by S1 nuclease protection studies was carried out and compared to the results of primer extension analyses, in order to locate map positions of the 5' termini of each early mRNA. The lengths of the products of in vitro transcription, from DNA templates which possess the transcription start regions of each of the early genes, were determined and compared to the lengths of DNA products generated by S1 nuclease protection and primer extension, in order to demonstrate that the 5' termini identified by S1 mapping and primer extension are due to transcription initiation and not to mRNA processing. For each of the early genes in the HindIII D fragment, transcription starts within 25 nucleotides of the translation initiation codon. The precise location of the 3' termini of each early transcript was identified by S1 nuclease mapping. In all but one case, the 3' ends map within 75 nucleotides of the putative transcription termination signal TTTTTNT [G. Rohrmann, L. Yuen, and B. Moss (1986).

The vaccinia virus HindIII D fragment is 160,060 bp in length and encodes 13 complete open reading frames [Niles et al. (1986) Virology 153, 96-112; S. L. Weinrich and D. E. Hruby (1986). Nucleic Acids Res. 14, 3003-3016]. We have employed a two-step Northern hybridization protocol using single-stranded DNA probes from M13 recombinants in order to identify the mRNA products from the 13 genes. Six of these genes are expressed only at early times after infection; six are transcribed only at late times; one gene is expressed at both early and late times after virus infection. The D11 gene is transcribed into two late mRNA species, one full-length and the other derived from the 3' one-third of the coding sequence. Translation of hybrid-selected mRNA was carried out in an attempt to identify the protein products encoded by each mRNA. Protein products were found for each early gene but translation was successful for only two of the eight late mRNAs. With the completion of the physical map it is apparent that the early and late genes in the HindIII D fragment are arranged in order to minimize potential interference caused by the expression of closely packed viral genes.

The map positions of the 5' ends of eight late mRNAs from the vaccinia virus HindIII D fragment were determined by a combination of S1 nuclease-protection studies and by primer extension analysis. For genes D2, D8, D10, and D11, a single set of 5' ends can be observed by S1 nuclease analysis which maps just upstream from the translation start site for each gene. For genes D3, D6, and D11a the situation is more complex. In addition to the ATG proximal family of protected DNA fragments, multiple larger protected DNA fragments map to sites up to several hundred base pairs upstream from the coding region. When primer extension mapping is carried out, large extended products are observed in all cases but that of gene D10. For genes D2, D8, and D13, these large DNA products are heterogenous in length and much longer than the S1 nuclease-protected DNA fragments. This has been observed previously for the late mRNA from the 11K gene by Bertholet et al. [(1987). Cell 50, 153]. In the case of mRNA from genes D3 and D6, however, the lengths of the extended DNA primers agree with the lengths of the S1 nuclease-protected DNA fragments. Therefore, for genes D3 and D6, the 5' regions of the mRNA must be derived from transcription of the DNA sequences upstream from the coding region of each gene. Since the structures at the 5' ends of the late mRNA assume more than one form, there may be multiple pathways for generating late mRNA.

Vaccinia virus gene D12L, which lies between nucleotides 14,350 and 13,487 in the HindIII D fragment, is transcribed at early times in infection and is capable of encoding a protein 287 amino acids in length with a predicted molecular mass of 33,331. A polyclonal antiserum was raised in rabbits to a fusion protein containing 279 amino acids of the D12L protein, and this serum was used to investigate both the time of synthesis and the function of the D12L protein. A combination of Western blot analysis and immunoprecipitation from pulse-labeled and pulse-chased cell extracts demonstrated that the synthesis of a 31-kDa protein begins early in infection, that it reaches a plateau by about 4 hr, and that it is stable in the infected cell. The D12L protein was localized by Western blot analysis of detergent-solubilized virions to the sodium deoxycholate soluble fraction which suggested that it may be a virion core-associated enzyme. Due to the similarity in apparent molecular weight between the D12L protein and the small subunit of the vaccinia mRNA capping complex the anti-D12L antiserum was employed in Western blot analysis of fractions generated during the purification of the virion mRNA capping enzyme. The 31-kDa D12L protein copurified with the virus capping enzyme through chromatography on heparin-agarose and phosphocellulose and also cosedimented with the capping enzyme through a glycerol density gradient. In addition, the anti-D12L antiserum coprecipitated the large subunit of the capping enzyme, confirming that gene D12L encodes the small subunit of the viral mRNA capping enzyme. An insertion mutation which destroys the gene D12L coding sequence was constructed in a plasmid containing a portion of both genes D11L and D12L and this plasmid was used to rescue a ts mutation, in a single step, in the adjacent gene D11L. Southern blot analysis of the re-plaque-purified virus permitted the identification of the mutant virus only when the mutant was propagated in the presence of wild-type helper virus. We concluded from these data that gene D12L is essential for virus propagation in tissue culture.

From July 1984 to December 1985, hemihepatectomy was done in 20 liver cancer patients under normothermic interruption of porta hepatis. There were 19 primary and 1 secondary liver carcinomas. Of the former, 17 (89%) were associated with mild or moderate cirrhosis. The peak age ranged 36-60 years. Right hemihepatectomy was performed in 18 and left hemihepatectomy in 2 with an operative mortality of 0%. Hepatic failure or secondary bleeding was not found. In the specimens resected, the largest weight was 2,500 gm. The normothermic interruption of porta hepatis usually lasted 15-25 minutes, a time long enough for hemihepatectomy. This procedure, being simple in manipulation and less detrimental to physiologic and biochemical balance in the human body, is relatively practical and beneficial to hepatectomy.