m-calpain in rat growth plate chondrocyte cultures: its involvement in the matrix mineralization process

m-Calpain, a Ca(2+)-dependent neutral cysteine proteinase (EC 3.4.22.17), has been demonstrated to be present in the lower hypertrophic zone of the rat growth plate. Using the pelleted culture system as an in vitro model of rat epiphyseal chondrocyte differentiation, we studied m-calpain contents and activities in pelleted cultures during chondrocyte differentiation and the role of m-calpain in the mineralization process. m-Calpain was demonstrated immunohistochemically in epiphyseal chondrocytes, and immunoreactive m-calpain content in cells increased with terminal differentiation into hypertrophic cells. Immunoblotting also showed the association of the increase in m-calpain in cell pellets and in cell culture medium with development of the culture. Ca(2+)-dependent caseinolytic activities of m-calpain extracted from cell pellets and from the medium increased with chondrocyte differentiation, coincident with the increase in enzyme content. The inhibition of m-calpain by the addition of calpastatin, a specific inhibitor of calpain, caused suppression of matrix mineralization in pelleted cultures; the addition of E-64c, a specific inhibitor of cysteine proteinases, during the mineralization stage also caused a significant inhibition of the matrix mineralization. The addition of E-64c resulted in altered composition of proteoglycan monomers and aggregates in cell pellets and in suppression of mineral growth. These findings support an important role of cysteine proteinases, especially m-calpain, in the regulation of the cartilage mineralization process through proteoglycan degradation.

Angiotensin I-converting enzyme gene polymorphism is associated with myocardial infarction, but not with retinopathy or nephropathy, in NIDDM

OBJECTIVE

To clarify the relationship between the angiotensin I-converting enzyme (ACE) gene polymorphism and diabetic micro- and macroangiopathy in patients with non-insulin-dependent diabetes mellitus (NIDDM).

RESEARCH DESIGN AND METHODS

We examined 267 NIDDM patients with various stages of diabetic retinopathy, 61 patients with myocardial infarction (MI), and 136 patients without MI. An insertion/deletion polymorphism of the ACE gene was typed by polymerase chain reaction.

RESULTS

Although no association was found between ACE gene polymorphism and diabetic retinopathy or nephropathy, this polymorphism was associated with MI in the patients with NIDDM. Homozygotes for the deletion polymorphism (DD genotype) were found more frequently in diabetic patients with MI (31.1%) than in diabetic patients without ischemic heart disease (16.9%), with a relative risk of 2.22 (95% confidence interval 1.11-4.46, P = 0.024).

CONCLUSION

These data indicate that ACE gene polymorphism is associated with MI, but not with retinopathy or nephropathy, in patients with NIDDM and suggest that the ACE gene confers susceptibility to diabetic macroangiopathy but not to microangiopathy.

Fetal pancreas transplantation in miniature swine. V. The functional and immunodulatory effects of ultraviolet light on fetal pig islets

We have used the pig as a large animal model for studies of fetal pancreas transplantation. Fetal pig pancreas (FPP) has also been proposed as a potential source of endocrine cells for the treatment of diabetes mellitus. Among the approaches to prevent rejection, the irradiation of donor islets with ultraviolet B light has been used for its immunomodulating properties. Our goal was to study in vitro the effects of UV-B irradiation of FPP on the function and immunogenicity of the tissue. FPP were collagenase-digested and cultured for 1-29 days prior to UV-B irradiation. Static incubation tests were used to measure glucose-theophylline stimulated insulin release. Data obtained at 300 J/m2 revealed no impairment of insulin release (78% to 129% of controls, P = ns). At 500 J/m2, a significant reduction of glucose-theophylline stimulated insulin release was observed with 50-60-day-old FPP (35% to 66% of controls, P < 0.05), but not with 80-day-old FPP (93% of controls, P = ns). At both doses, prolonged observation in culture did not show any alteration of the growth and proliferation of islet cell clusters. UV-irradiated (300 J/m2) adult and fetal pig islet allografts released C-peptide and survived > 200 days. The immunogenicity of irradiated tissues was determined in vitro with allogeneic mixed islet-lymphocyte cultures (MILC). Proliferative responses of allogeneic lymphocytes to UV-irradiated FPP were very significantly decreased by 52-91% at both 300 and 500 J/m2 doses. This effect was observed from 1 to 10 days following UV irradiation and was not modulated by exposure of the tissues to gamma-interferon. We conclude that UVB-irradiation of FPP at a dose of 300 J/m2 does not alter its endocrine function and growth and is effective in reducing tissue immunogenicity. This treatment may be a useful approach for fetal islet transplantation in large animal models.

Involvement of cholinergic systems in the deficit of place learning in Morris water maze task induced by baclofen in rats

Effects of oxotremorine on the deficit of place learning in the Morris water maze task induced by baclofen and scopolamine were examined to determine the involvement of brain cholinergic systems in the deficit of learning induced by baclofen. Rats were given 4 training trials per day with the submerged platform at a fixed location in the maze for 4 days. On day 4, rats were required to swim in the pool without the platform after the 4th training trial (probe test). Baclofen as well as scopolamine dose-dependently increased the escape latency in the training trials. In the probe test, baclofen as well as scopolamine dose-dependently reduced the duration in the quadrant where the platform had been originally located. Increased latency in the training trials and reduced duration in the probe test induced by scopolamine were dose-dependently attenuated by oxotremorine. Increased latency and reduced duration in the baclofen-treated rats were improved by oxotremorine as well as 2-hydroxysaclofen. Baclofen but not scopolamine induced motor incoordination in the rotarod test. Oxotremorine failed to improve motor incoordination induced by baclofen. These results suggest that cholinergic systems may be involved in the deficit of place learning induced by baclofen, and that the ameliorative effects of oxotremorine may not be due to improvement of motor incoordination.

Activation of Stat5 by interleukin 2 requires a carboxyl-terminal region of the interleukin 2 receptor beta chain but is not essential for the proliferative signal transmission

The high-affinity interleukin 2 (IL-2) receptor (IL-2R) consists of three subunits: the IL-2R alpha, IL-2R beta c, and IL-2R gamma c chains. Two members of the Janus kinase family, Jak1 and Jak3, are associated with IL-2R beta c and IL-2R gamma c, respectively, and they are activated upon IL-2 stimulation. The cytokine-mediated Jak kinase activation usually results in the activation of a family of latent transcription factors termed Stat (signal transducer and activator of transcription) proteins. Recently, the IL-2-induced Stat protein was purified from human lymphocytes and found to be the homologue of sheep Stat5/mammary gland factor. We demonstrate that the human Stat5 is activated by IL-2 and that Jak3 is required for the efficient activation. The cytoplasmic region of the IL-2R beta c chain required for activation of Stat5 is mapped within the carboxyl-terminal 147 amino acids. On the other hand, this region is not essential for IL-2-induced cell proliferation.

Preferential formation of the hydroperoxide of linoleic acid in choline glycerophospholipids in human erythrocytes membrane during peroxidation with an azo initiator

The formation of phospholipid hydroperoxides was monitored in human red blood cell (RBC) membranes that had been peroxidized with an azo initiator. Peroxidation of RBC membranes caused a profound decrease in the amount of polyunsaturated fatty acids and concomitantly hydroperoxides, as primary products of peroxidation, appeared in the phospholipids. Hydroperoxides were predominantly generated in choline glycerophospholipid (CGP), while the extent of formation of ethanolamine glycerophospholipid (EGP) hydroperoxides was low and their presence was transient. Hydroxy and hydroperoxy moieties in CGP were identified as 9-hydroxy and 13-hydroxy octadecanoic acid, derived from linoleic acid, by gas chromatography-mass spectrometric analysis. No consistent generation of hydroperoxide from arachidonic acid was evident in CGP. The CGP-hydroperoxide accounted for approximately 76% of linoleic acid consumed during peroxidation of RBC membranes. The prominent generation of phospholipid hydroperoxides was observed in the linoleic acid-rich membranes from rabbit RBC, indicating that the level of linoleic acid in phospholipids determines, in part, the extent of formation of phospholipid hydroperoxides. Aldehydic phospholipids, as secondary products of peroxidation, were detected in oxidized membranes. EGP was the most prominent aldehydic phospholipid, while negligible amounts of aldehydic CGP were formed. This study indicates that the process of oxidation of individual phospholipids clearly differs among phospholipids and depends on the structure of each.

A boy with atrophic thyroiditis of prepubertal onset, who was positive for TSH-binding inhibitor immunoglobulins

A 12 year old boy was admitted to our hospital because of short stature. From the age of 7, his growth velocity decreased and he manifested intolerance to low temperatures, hoarseness, dry skin, and slowness of thought and physical movement. On admission, his height was 129.8 cm (-3 s.d.) and his body weight was 43.2 kg (-0.5 s.d.). His clinical features also included relaxation phase of tendon reflexes, periorbital puffiness and cold skin but no struma. His bone age was 9 years. His serum thyroxine (T4), triiodothyronine (T3), free T4 and free T3 were low, while his thyrotropin was high. He was positive for antithyroglobulin antibodies, antimicrosomal antibodies, and TSH-binding inhibitor immunoglobulins. He was diagnosed as having atrophic thyroiditis. We also determined the HLA haplotypes of his family members. His father's HLA haplotypes were A2, BW61(a) and A24, BW52(b), while his mother's haplotypes were A24, BW52(c) and A30, BW60(d). The HLA haplotypes of both the patient and his younger brother showed a and d, while the patient's elder brother's HLA haplotypes showed b and c. His family members all had normal thyroid function, but his father was positive for antimicrosomal antibodies. In summary, we describe a rare case where the onset of hypothyroidism was prepubertal, where the pathogenesis may have involved TSH-receptor blocking antibodies, and where the inheritance of the disease may have been from the paternal side of the family.

Phosphatidylserine-specific transbilayer lipid translocation in synaptosomal plasma membranes from Narke japonica

We measured the translocation of exogenous radiolabeled phospholipid probes from the outer to the inner leaflet in the synaptosomal plasma membranes from the electric organs of Narke japonica, a Japanese marine ray. These radioactive probes can provide a convenient and highly sensitive means of measuring the translocation kinetics of phospholipids between outer and inner leaflets of biomembranes that are available only with low yield [Anzai et al. (1993) Biochim. Biophys. Acta 1151, 69-75]. Translocation kinetics revealed that the behavior of phosphatidylserine (PS), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) differed. PS quickly disappeared from the outer leaflet of the bilayer. The translocation of PE and PC was slow and about 80% of the PE- and PC-probes remained in the outer leaflet at 3 h. These results differ from those of translocation in erythrocyte membranes measured using the same probes, where aminophospholipid translocase translocated both PS and PE from the outer to the inner leaflet of the bilayer, although the rate was faster for PS than for PE. In this study, the translocation was apparently PS-specific, and it was inhibited by SH reagent or intrasynaptosomal ATP-depletion. These findings clearly demonstrate that the translocation is driven by an ATP-dependent protein, which has apparent PS-specificity. We suggest that there is a translocase other than erythrocyte-type aminophospholipid translocase in synaptosomal plasma membranes from N. japonica.

[Comparison by twin impinger of the distribution patterns of two beclomethasone dipropionate metered dose inhalers and of two spacer devices]

A Twin Impinger was used to assess the influence of the number of puffs on the distribution patterns of two commercially available beclomethasone dipropionate (BDP) metered dose inhalers, and the effects of two kinds of spacer devices were also compared. No difference was observed in the distribution pattern up to the 10th puff between the two metered dose inhalers. Clinically, the amount of BDP inhaled into the lungs is said to depend on the number of puffs taken, but in this study, there was a significant difference in the distribution pattern between these 2 inhalers. In the stage assumed to represent the oropharynx site, the distribution ratio of BDP was greater after administration with an Aldecin than with a Becotide inhaler. In contrast, in the stage assumed to represent the lung, the distribution ratio of BDP was greater with the Becotide inhaler. This result suggests that the amount of BDP inhaled in the lungs may vary between these two preparations. The effects of spacer devices were also investigated in 4 puffs. These spacer devices caused the distribution ratio in the stage assumed to represent the oropharynx to decrease by at least 90%, irrespective of the type of metered dose inhaler. This result suggests that spacer devices are useful in reducing local side effects in the oropharynx. In the stage assumed to represent the lung, the distribution ratio achieved with the Becotide inhaler with Volumatic was greater than that with the Aldecin with InspirEase. This study suggests that the best therapeutic effects can be expected from a combination of Becotide inhaler and Volumatic.

Muscimol induces state-dependent learning in Morris water maze task in rats

Effects of muscimol on the place learning in Morris water maze task were investigated in rats. Rats were given 4 training trials per day with the submerged platform at a fixed location in the maze for 4 days. On day 4, rats were required to swim in the pool without the platform after 4 training trials (probe test). Compared to the saline-treated rats, the rats treated with muscimol on day 1-4 showed no modifications of place learning in the training trials and the probe test. However, in the rats treated with muscimol on day 1-3 and treated with saline on day 4, there was increased latency to reach the platform and reduced duration in the quadrant where the platform had been located on day 4. The increased latency in the training trials and reduced duration in the probe test on day 4 was blocked by bicuculline, when bicuculline and muscimol were co-administered on day 1-3, and saline was injected on day 4. Moreover, in the rats treated with muscimol on day 1-3, co-administration of bicuculline and muscimol on day 4 blocked place learning: increased latency in the training trials and reduced duration in the probe test was observed. These results suggest that muscimol induces state-dependent learning (SDL) in Morris water maze task, and that muscimol-induced SDL is mediated by GABAA receptors.

Identification and quantitation of choline glycerophospholipids that contain aldehyde residues by fluorometric high-performance liquid chromatography

A high-performance liquid chromatographic method was established for the fractionation of oxidized choline glycerophospholipids (CGPs) that contain aldehyde residues, after their derivatization with a fluorescent reagent 4-(N,N-dimethylaminosulfonyl)-7-hydrazino-2,1,3-benzoxadiazole (DBD-H). DBD-H efficiently reacted with the aldehyde residues of phospholipids at room temperature. Fluorescent derivatives of aldehydic phospholipids were well separated into species that contained aldehyde groups at different sites. The relationship between the amount of each derivative and the signal was linear over a wide range and amounts as low as several picomoles of aldehydic CGP could be detected. This method is applicable to the quantitation of aldehydic phospholipids in peroxidized membranes of red blood cells. In the present study, formation of aldehydic choline glycerophospholipids was demonstrated for the first time in peroxidized red blood cell membranes and the compounds were quantitated.

Isolation and mapping of 186 new DNA markers on human chromosome 1

To obtain DNA markers on human chromosome 1, we first isolated 500 cosmid clones from mouse A9 cells containing a human chromosome 1 tagged with pSV2neo. Of these, 186 were localized on each band of human chromosome 1 by R-banding fluorescence in situ hybridization; 118 and 68 were on the short and long arms, respectively. We performed restriction fragment length polymorphism (RFLP) analysis of these cosmid clones, and polymorphism was recognized with one or more enzyme in 43 of them. Two markers proved to have variable numbers of tandem repeats. Since several tumor suppressor genes, as well as genes responsible for hereditary disorders, may be located on this human chromosome, the DNA markers will be useful for RFLP analysis or the isolation of new genes related to various disorders.

Metabolism and cytotoxicity of propyl gallate in isolated rat hepatocytes: effects of a thiol reductant and an esterase inhibitor

The relationship between the metabolism and the cytotoxic effects of propyl gallate (PG) has been studied in freshly isolated rat hepatocytes. Addition of PG (0.5-2.0 mM) to the hepatocytes elicited concentration-dependent cell death, accompanied by decreases in intracellular ATP, adenine nucleotide pools, glutathione, and protein thiols. The rapid loss of ATP preceded the onset of cell death. PG in the hepatocyte suspensions was converted to gallic acid, 4-O-methyl-gallic acid, and other minor products over time. In addition, PG was converted to a dimer [dipropyl-4,4',5,5',6,6'-hexahydroxydiphenate (PG-dimer)] and ellagic acid via autooxidation. In comparisons of the toxic effects of PG and its metabolites at concentrations of 2 mM, the parent compound PG was the most toxic. Pretreatment of hepatocytes with diazinon (100 microM), an esterase inhibitor, enhanced PG-induced cytotoxicity. This was accompanied by delay of PG loss and inhibition of gallic acid formation. The cytotoxicity of PG was also enhanced by addition of the thiol reductant dithiothreitol (4 mM), although intracellular levels of glutathione and protein thiols were maintained during the incubation period. Dithiothreitol did not affect the hydrolysis of PG to gallic acid by esterases but did delay the conversion of PG and prevented the formation of PG-dimer. In isolated hepatic mitochondria, PG elicited a concentration-dependent increase in the rate of state 4 oxygen consumption, indicating an uncoupling effect. In contrast, PG-dimer inhibited the rate of state 3 oxygen consumption. Based on the respiratory control index, the order of potency for impairment of mitochondria was PG > PG-dimer > gallic acid = 4-O-methyl-gallic acid = ellagic acid - propyl alcohol. These results indicate (a) that PG-induced hepatotoxicity is mediated by the parent compound and not its metabolites, (b) that toxicity is associated with ATP depletion apparently independently of cellular thiol depletion, and (c) that mitochondria may represent critical targets of PG-induced cytotoxicity.

Evaluation of vascular compliance and vasoconstrictive reactions in amputated hindlimbs of rats

The vascular compliance and the contractility of vascular smooth muscle of preserved, amputated hindlimbs of rats were evaluated using a fresh blood extracorporeal circulatory system. Vascular compliance was measured under physiologic circulatory conditions (blood pressure of the amputated limb was maintained at 80-150 mm Hg [10-20 kPa]) and found not to differ significantly from that of freshly amputated limbs after storage at 4 degrees C for 12 hours. However, after more than 24 hours of storage at 4 degrees C, the vascular compliance decreased significantly (p < 0.01). To evaluate the contractility of vascular smooth muscle, the arterial blood pressure in the amputated limbs was transiently increased with injections of norepinephrine. The contractility could be preserved for at least 12 hours at 4 degrees C; however, it decreased markedly after more than 24 hours. The vascular compliance and vasoconstrictive reactions of the amputated limbs were maintained for at least 12 hours at 4 degrees C.

Activity of ecdysone analogs in enhancing N-acetylglucosamine incorporation into the cultured integument of Chilo suppressalis

Ecdysone analogs with various side chains at the 17-position of the steroid structure enhanced the incorporation of N-acetylglucosamine as 20-hydroxyecdysone into the cultured integument prepared from Chilo suppressalis. Their activity in terms of the concentration required to give 50% of the maximum response varied with the structure. Piperonyl butoxide, an inhibitor of oxidation metabolism, did not enhance the in vitro effect of the compounds. The order of potency was ponasterone A > 20-hydroxyecdysone > cyasterone > inokosterone > makisterone A >> ecdysone.

Death with dignity in the Japanese culture

In Japanese culture, the concept of death with dignity focuses on enhancing the relationship with significant others (especially with family members) and is expected to continue even after death, unlike the autonomous decision making in Western cultures. Deaths in such relationships are self-worthy, majestic and wished for. The author depicts these traits by describing the worship of sudden death aspiration in a special temple, the death ceremonies repeated even after death which involve even distantly related people, a suicide allusively asking for something, and a joint suicide.

A new mitochondrial DNA mutation associated with non-insulin-dependent diabetes mellitus

Mitochondria play an important role in glucose-induced insulin secretion in pancreatic beta cells. We therefore examined whether patients with NIDDM exhibit genetic variability in mitochondrial DNA (mtDNA), a candidate gene for NIDDM. We sequenced mtDNA in the region encoding tRNALeu and the adjacent region in several diabetic patients with clinical features suggesting mitochondrial DNA mutations. We found a new point mutation at position 3316 that leads to an amino acid change in the ND-1 protein. The frequency of the mutation was screened with PCR-RFLP in 295 NIDDM patients and 406 controls. We found ten NIDDM patients (3.4%) harbored the mutation. Although 4 control subjects had the mutation, the frequency was significantly higher in the NIDDM patients than in the control subjects (p = 0.02). These results suggest that the 3316 mutation is associated with NIDDM.

[Hypoparathyroidism in infants]

Hypoparathyroidism (HP) of infant is very rare but an important disease in childhood. Because the symptom of its onset in this period is mainly generalized convulsion due to hypocalcemia. So immediate discrimination from many other diseases caused generalized convulsion must be needed. In this chapter, its clinical symptoms, diagnosis and treatment are described. With the recent advance of molecular biology, abnormalities of PTH gene in familial idiopathic hypoparathyroidism have been discovered. In near future, the analysis of PTH gene will be more helpful about the diagnosis and the treatment of HP.

Effect of angina pectoris on myocardial protection in patients with reperfused anterior wall myocardial infarction: retrospective clinical evidence of "preconditioning"

OBJECTIVES

We examined whether angina pectoris occurring shortly before the onset of acute myocardial infarction can actually preserve postischemic left ventricular function in humans.

BACKGROUND

Experimental studies indicate that brief, transient episodes of ischemia render the heart very resistant to infarction from a subsequent sustained ischemic insult, an effect termed ischemic preconditioning. However, no clinical data are available concerning the implications of angina pectoris shortly before the onset of infarction in humans.

METHODS

We studied 84 patients with an acute anterior myocardial infarction. All patients had total occlusion of the proximal or medial portion of the left anterior descending coronary artery and achieved reflow within 6 h of onset. Patients were classified into three groups on the basis of duration of antecedent angina pectoris: group 1 = no angina (37 patients); group 2 = new angina pectoris occurring < or = 7 days of onset of infarction (22 patients); group 3 = angina pectoris beginning > 7 days before onset of infarction (25 patients). All patients underwent left ventriculography on the day of, and 28 days after, onset of infarction to determine ejection fraction and regional wall motion in the territory of the left anterior descending coronary artery by the centerline method.

RESULTS

Angiographic collateral flow grade was higher in group 3 than in groups 1 and 2 ([mean +/- SD] group 1 = 0.08 +/- 0.7, group 2 = 0.7 +/- 0.7, group 3 = 1.5 +/- 0.8). Although there were no differences in baseline ejection fraction and regional wall motion among the three groups, the degree of improvement was significantly greater in groups 2 and 3 than in group 1 (late minus baseline ejection fraction: group 1 = 0 +/- 8%, group 2 = 7 +/- 10% group 3 = 6 +/- 10% [p < 0.05 group 1 vs. groups 2 and 3]; late minus baseline regional wall motion: group 1 = 0.2 +/- 0.4, group 2 = 0.6 +/- 0.5, group 3 = 0.5 +/- 0.6 SD/chord [p < 0.05, group 1 vs. group 2]). When the study was limited to those patients with no or poor collateral flow (31 in group 1, 19 in group 2, 10 in group 3), only group 2 patients had a significant improvement in wall motion. Angina pectoris within 24 h before onset of infarction was more frequent in group 2 (82%) than group 3 (28%, p < 0.05).

CONCLUSIONS

Episodes of angina pectoris occurring shortly before the onset of infarction may preserve myocardial contractile function in reperfused myocardial infarction despite less support from collateral flow channels, although these are suggestive results in a limited number of patients.

Allelic variation of apolipoprotein E in Japanese sporadic Creutzfeldt-Jakob disease patients

We analyzed apolipoprotein E (apo E) genotypes in 53 Japanese sporadic Creutzfeldt-Jakob disease (CJD) patients and 100 normal controls using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. The apo E allelic frequencies in Japanese sporadic CJD patients and our control population were as follows: epsilon 2, 6.6% versus 7.5%; epsilon 3, 82.1% versus 81.5%; epsilon 4, 11.3% versus 11.0%. The mean ages at onset in Japanese sporadic CJD patients were as follows: epsilon 3/epsilon 3, 63.8 years; epsilon 3/epsilon 4, 66.3 years; epsilon 2/epsilon 3, 68.6 years. These results indicate that there is no association between apo E genotype and sporadic CJD in Japan.

Structure of the gene encoding the alpha subunit of the human interleukin 3 receptor

Interleukin 3 is a cytokine that stimulates proliferation and differentiation of hematopoietic progenitor cells. Its receptor consists of two subunits, an interleukin 3-specific alpha subunit and a beta subunit shared by garanulocyte-macrophage colony stimulating factor and interleukin 5 receptors. In this paper, we determined the genomic structure of the alpha subunit of the human interleukin 3 receptor, which spans approximately 40 kb and has 12 exons. We found that the genomic structures of the alpha subunits of the human interleukin 3 and granulocyte-macrophage colony stimulating factor receptors are very similar. They possess a unique additional intron in the 'C domain', which is absent in the alpha subunit of the interleukin 5 receptor. These results suggest a shared evolutionary pathway of these two genes.

[Bacteriological and clinical evaluation tazobactam/piperacillin in infectious diseases in surgical field]

We carried out bacteriological and clinical studies on tazobactam/piperacillin (TAZ/PIPC), a combination drug of piperacillin with the new beta-lactamase inhibitor tazobactam, in various infectious diseases in surgical field such as intra-abdominal infections (peritonitis and intra-abdominal abscess), hepatobiliary infections (cholecystitis, cholangitis and hepatic abscess) and secondary infections in wound, etc. The total number of cases treated with the combination drug was 164. Of these cases, 141 cases were assessable for clinical responses including 60 cases with intra-abdominal infections, 38 cases with hepatobiliary infections, and 43 cases with secondary infections. Clinical efficacy rates of the drug were 83.3% in cases with intra-abdominal infections, 86.8% in cases with hepatobiliary infections, and 95.3% in those with secondary infections, hence the overall efficacy rate was 87.9%. In the cases from which beta-lactamase producing strains were isolated, clinical efficacy rates were 84.8% in cases with intra-abdominal infections, 84.6% in those with hepatobiliary infections, and 96.2% in those with secondary infections, hence the overall efficacy rate was 88.9%. Bacteriological efficacy rates were 92.9% in cases with Gram-positive bacterial infections, 64.3% in those with Gram-negative bacterial infections, and 100% in those with anaerobic bacterial infections. Bacteriological efficacy rates were 84.2% in cases with single bacterial infections and 56.5% in those with multi-bacterial infections, and the overall bacteriological efficacy rate was 69.0%. In the cases of infections with beta-lactamase producing strains, bacteriological efficacy rates were 80.0% in cases with Gram-positive bacterial infections, 75.0% in those with Gram-negative bacterial infections, and 100% in those with anaerobic bacterial infections. They were 82.6% in cases with single bacterial infections and 57.9% in those with multi-bacterial infections; the overall bacteriological efficacy rate was 67.2%. The bacterial eradication rate was 79.9% against all the isolates, and it was 79.2% against beta-lactamase producing isolates. In addition, we compared the sensitivity distribution of the isolates to TAZ/PIPC with those to control drugs piperacillin (PIPC), cefotiam (CTM), ceftazidime (CAZ), sulbactam/cefoperazone (SBT/CPZ). The MIC50 and MIC90 values of TAZ/PIPC against all strains were 3.13 micrograms/ml and 50 micrograms/ml, respectively. MIC50 values show that TAZ/PIPC was two times less effective than CAZ and SBT/CPZ but four times more effective than CTM; furthermore, from the MIC90 values, TAZ/PIPC was four times more effective than PIPC, CTM and CAZ. The MIC50 and MIC90 values of TAZ/PIPC against beta-lactamase producing strains were 3.13 micrograms/ml and 50 micrograms/ml, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)