Predictors for onset of extended-spectrum beta-lactamase-producing Escherichia coli-induced bacteraemia: a systematic review and meta-analysis

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli bacteraemia can induce unfavourable clinical outcomes due to delay in appropriate antimicrobial treatment and limited therapeutic options. Therefore, elucidating the predictors of ESBL-producing E. coli-induced bacteraemia is crucial to improve clinical outcomes. However, a literature search did not reveal any studies that incorporate a meta-analysis of the predictors of ESBL-producing E. coli-induced bacteraemia. As such, this review was undertaken to assess current evidence on the predictors of ESBL-producing E. coli-induced bacteraemia. PubMed, Web of Science and Cochrane Library databases were searched for all relevant publications from January 2000 to September 2021. This systematic review evaluated 10 observational studies, comprising a total of 2325 patients with E. coli-induced bacteraemia and 850 (36.6%) ESBL-producing strains. In the meta-analysis, previous antibiotic therapy [pooled risk ratio (RR) 2.72; P<0.001], especially with cephalosporins (pooled RR 4.66; P<0.001) and quinolones (pooled RR 5.47; P<0.001), and urinary catheter use (pooled RR 3.79; P<0.001) were predictive of ESBL-producing E. coli-induced bacteraemia. Antibiotic therapy for patients with the above-mentioned risk factors should be selected considering the possibility of ESBL-producing E. coli-induced bacteraemia compared with non-ESBL-producing E. coli-induced bacteraemia. It is important to elucidate whether appropriate modulation of the identified risk factors can potentially mitigate the risk of ESBL-producing E. coli-induced bacteraemia compared with non-ESBL-producing E. coli-induced bacteraemia.

Effects of smoking cessation on endothelial function assessed by flow-mediated dilation and reactive hyperemia peripheral artery tonometry

Background

Smoking predisposes individuals to endothelial dysfunction. Both flow-mediated dilation (FMD) and reactive hyperemia peripheral artery tonometry (RH-PAT) are used to assess endothelial function. However, there are differences in the physiology of vascular beds being tested and in the response of conduit and resistive vessels to RH. Therefore, whether smoking cessation demonstrates comparable effects on endothelial function evaluated by FMD and by RH-PAT remains unclear.

Purpose

We aimed to evaluate the effects of smoking cessation on endothelial function evaluated simultaneously by FMD and RH-PAT.

Methods

Thirty-eight consecutive current smokers (mean±standard deviation; age, 65±10 years) who visited our smoking cessation outpatient department and succeeded in smoking cessation with varenicline were enrolled. Clinical variables, FMD, and natural logarithmic transformation of the reactive hyperemia index (Ln-RHI) were examined before and 20 weeks after treatment initiation. Fifteen current smokers who failed in smoking cessation were enrolled as age- and sex-matched controls. The Spearman's rank correlation coefficient and intraclass correlation coefficient (ICC) for a two-way mixed effects model were performed to assess the agreement of changes in FMD and Ln-RHI. Multivariate logistic regression analysis was performed to examine the associations between the presence of increase in FMD or Ln-RHI and clinical variables.

Results

FMD significantly improved after smoking cessation (3.42%±1.96% to 4.45%±2.28%; p=0.019), whereas Ln-RHI did not (0.53±0.25 to 0.59±0.21; p=0.223). The Spearman's rank correlation coefficient between changes in FMD and Ln-RHI was −0.013, and the ICC was −0.002 (p=0.506). In the multivariate logistic regression analysis, an increase in FMD or Ln-RHI was predicted based on the baseline FMD (odds ratio = 0.54, p=0.013) or Ln-RHI (odds ratio = 0.36, p=0.012), respectively, after adjusting for age and sex.

Conclusions

There was significant improvement in the endothelial function assessed by FMD, but not by Ln-RHI, after smoking cessation. In addition, there was disagreement between changes in FMD and those in Ln-RHI. Smoking cessation may have varying effects on the endothelial function of the conduit and digital vessels.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-aid for scientific research from the ministry of education, science and culture of Japan

Nitric oxide and related enzymes in asthma: relation to severity, enzyme function and inflammation

BACKGROUND

Exhaled nitric oxide (FeNO) associates with asthma and eosinophilic inflammation. However, relationships between nitric oxide synthases, arginase, FeNO, asthma severity and inflammation remain poorly understood.

OBJECTIVES

To determine the relationships of iNOS expression/activation and arginase 2 expression with asthma severity, FeNO, nitrotyrosine (NT) and eosinophilic inflammation.

METHODS

Bronchial brushings and sputum were obtained from 25 normal controls, eight mild/no inhaled corticosteroids (ICS), 16 mild-moderate/with ICS and 35 severe asthmatics. The FeNO was measured the same day by ATS/ERS standards. The iNOS, arginase2 mRNA/protein and NT protein were measured in lysates from bronchial brushings by quantitative real-time PCR and Western blot. Induced sputum differentials were obtained.

RESULTS

Severe asthma was associated with the highest levels of iNOS protein and mRNA, although the index of iNOS mRNA to arginase2 mRNA most strongly differentiated severe from milder asthma. When evaluating NO-related enzyme functionality, iNOS mRNA/protein expression both strongly predicted FeNO (r = 0.61, P < 0.0001 for both). Only iNOS protein predicted NT levels (r = 0.48, P = 0.003) with the strongest relationship in severe asthma (r = 0.61, P = 0.009). The iNOS protein, FeNO and NT, all correlated with sputum eosinophils, but the relationships were again strongest in severe asthma. Controlling for arginase 2 mRNA/protein did not impact any functional outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

These data suggest that while iNOS expression from epithelial brushings is highest in severe asthma, factors controlling arginase2 mRNA expression significantly improve differentiation of severity. In contrast, functionality of the NO pathway as measured by FeNO, NT and eosinophilic inflammation, is strongly associated with iNOS expression alone, particularly in severe asthma.

Plasma concentration of amrubicinol in gamma phase in patients treated for 3 days with amrubicin and hematological toxicities

e14606

Background: Amrubicinol (AMR-OH) is an active metabolite of amrubicin (AMR), a novel synthetic 9-amino-anthracycline derivative. The time-concentration profile of AMR-OH exhibits a continuous long plateau slope in terminal phase. To determine the relationships between the steady-state plasma concentration of AMR-OH and treatment effects and toxicities associated with AMR therapy, we performed a PK/PD study of AMR in patients with lung cancer treated with AMR alone or the combination of AMR + cisplatin (CDDP). Methods: AMR was given at a dose of 30 or 40 mg/m2 on days 1 to 3. Plasma samples were collected at pretreatment, 24 hours after the 1st injection (day 2), and 24 hours after the 3rd injection (day 4). Plasma concentrations of AMR, AMR-OH, and CDDP were determined by HPLC and AAS. Percent change in neutrophil count (dANC) and the plasma concentration of AMR-OH were evaluated using a sigmoid Emax model. Results: A total of 35 patients with a median age of 65 years (range 40–78), including 10 with small cell lung cancer (SCLC), 23 with non-small cell lung cancer (NSCLC), 1 with thymic cancer, and 1 with neuroblastoma were enrolled. A total of 107 plasma samples were available for study. Mean concentrations of AMR on day 2, AMR on day 4, AMR-OH on day 2, and AMR-OH on day 4 were 8.52ng/mL+4.63, 16.55ng/mL+11.92, 7.28 ng/mL+3.56 SD, and 13.35ng/mL+5.56 (mean ± SD), with significant increase from day 2 to day 4 for both AMR (p<0.0001) and AMR-OH (p<0.0001). Significant relationships were observed between AMR-OH on day 4 and the toxicity grades of leukopenia, neutropenia, and anemia (p=.018, p=.012, and p=.025). Thrombocytopenia grade exhibited a tendency toward relationship with AMR-OH on day 4 (p = .081). No relationships were observed between drug concentrations and responses. The plasma concentration of AMR-OH on day 4 was positively correlated with dANC in the group of all patients, as well as in patients treated with AMR alone and in patients with co-administration with CDDP using a sigmoid Emax model. Conclusions: The plasma concentration of AMR-OH on day 4 was correlated with hematological toxicities in patients treated with AMR. Assessment of plasma concentration of AMR-OH at one time point might enable prediction of hematological toxicities.

No significant financial relationships to disclose.

Increased levels of angiopoietin-2 in induced sputum from smoking asthmatic patients

BACKGROUND

Active cigarette smoking has detrimental effects on asthma morbidity and severity. Angiopoietin-1 has been shown to protect the microvessels against plasma leakage, whereas angiopoietin-2 enhances vascular permeability and subsequently induces airway mucosal oedema. Therefore, it is recently thought that angiopoietin-2 may contribute to the pathophysiology of asthma.

OBJECTIVE

To determine whether angiopoietin-2 levels in the airways are associated with clinical profiles in smoking asthmatics.

METHODS

We measured angiopoietin-1 and -2 levels in induced sputum in 35 normal controls (18 non-smokers and 17 smokers) and 49 asthmatics (24 non-smokers and 25 smokers) before and after inhaled beclomethasone dipropionate (BDP: 800 microg/day) therapy for 12 weeks.

RESULTS

Angiopoietin-1 and -2 levels in induced sputum were significantly higher in asthmatics than in normal controls. Moreover, angiopoietin-2 levels were significantly higher in smoking asthmatics than in non-smoking asthmatics (P=0.0001). The airway vascular permeability index was also higher in smoking asthmatics than in non-smoking asthmatics. Moreover, the angiopoietin-2 level was positively correlated with the airway vascular permeability index (non-smoking asthmatics: r=0.87, P<0.001, smoking asthmatics: r=0.64, P=0.002). After BDP therapy, angiopoietin-1 levels were significantly decreased in non-smoking asthmatics, smoking-cessation asthmatics, and active-smoking asthmatics. In contrast, angiopoietin-2 levels did not differ from before to after BDP therapy in non-smoking asthmatics and active-smoking asthmatics. However, its levels were significantly decreased from before to after BDP therapy in smoking-cessation asthmatics (P=0.002). Although forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) before BDP therapy was comparable in all subgroups, this parameter after BDP therapy was significantly lower in active-smoking asthmatics than in non-smoking and smoking-cessation asthmatics. Moreover, the reduction in angiopoietin-2 levels after BDP therapy in smoking-cessation asthmatics was significantly correlated with an improvement in FEV(1)/FVC.

CONCLUSION

Angiopoietin-2 levels were elevated in the airways of smoking asthmatics, and its levels were associated with impaired airway responses.

Correlations of health-related quality of life questionnaire results in asthma and allergic rhinitis: effects of a leukotriene receptor antagonist

Bronchial asthma and allergic rhinitis frequently coexist. This study investigated correlations of health-related quality of life (QOL) questionnaires for these diseases, assessing whether the selective leukotriene receptor antagonist (LTRA), pranlukast, had additional benefits to overall asthma control when there was concomitant allergic rhinitis. Patients with asthma-associated allergic rhinitis were randomly allocated to either LTRA(+) (n = 21, treated for 3 months with pranlukast), or LTRA(-) (n = 8, no pranlukast). At study start and at 3 months, pulmonary function was evaluated and QOL assessments were made using the Asthma Health Questionnaire-Japan (AHQ-Japan) and the Japan Rhino-conjunctivitis Quality of Life Questionnaire (JRQLQ). Total scores were significantly correlated both before and after therapy. After 3 months' therapy, pulmonary function and total AHQ-Japan and JRQLQ scores significantly improved in the LTRA(+) group, but not in the LTRA(-) group. A significant correlation between change at 3 months in the AHQ-Japan and JRQLQ scores from baseline values was seen in the LTRA(+) group. LTRA therapy improved allergic rhinitis symptoms, asthma symptoms and pulmonary function.

Galectin-12, an Adipose-expressed Galectin-like Molecule Possessing Apoptosis-inducing Activity

Galectins constitute a family of proteins that bind to beta-galactoside residues and have diverse physiological functions. Here we report on the identification of a galectin-like molecule, galectin-12, in a human adipose tissue cDNA library. The protein contained two potential carbohydrate-recognition domains with the second carbohydrate-recognition domain being less conserved compared with other galectins. In vitro translated galectin-12 bound to a lactosyl-agarose column far less efficiently than galectin-8. Galectin-12 mRNA was predominantly expressed in adipose tissue of human and mouse and in differentiated 3T3-L1 adipocytes. Caloric restriction and treatment of obese animals with troglitazone increased galectin-12 mRNA levels and decreased the average size of the cells in adipose tissue. The induction of galectin-12 expression by the thiazolidinedione, troglitazone, was paralleled by an increase in the number of apoptotic cells in adipose tissue. Immunocytochemical analysis revealed that galectin-12 was localized in the nucleus of adipocytes, and transfection with galectin-12 cDNA induced apoptosis of COS-1 cells. These results suggest that galectin-12, an adipose-expressed galectin-like molecule, may participate in the apoptosis of adipocytes.

Recombinant human betacellulin promotes the neogenesis of beta-cells and ameliorates glucose intolerance in mice with diabetes induced by selective alloxan perfusion

Betacellulin (BTC), a member of the epidermal growth factor family, is expressed predominantly in the human pancreas and induces the differentiation of a pancreatic acinar cell line (AR42J) into insulin-secreting cells, suggesting that BTC has a physiologically important role in the endocrine pancreas. In this study, we examined the in vivo effect of recombinant human BTC (rhBTC) on glucose intolerance and pancreatic morphology using a new mouse model with glucose intolerance induced by selective alloxan perfusion. RhBTC (1 microg/g body wt) or saline was injected subcutaneously every day from the day after alloxan treatment. The intraperitoneal glucose tolerance test revealed no difference between rhBTC-treated and rhBTC-untreated glucose-intolerant mice at 2-4 weeks. However, glucose tolerance was significantly improved and body weight was significantly increased in rhBTC-treated mice compared with untreated mice at 8 weeks. Islet-like cell clusters, consisting mainly of beta-cells, were increased in the pancreas and were localized in contact with the ductal lining cells and sometimes with acinar cells. In conclusion, administration of rhBTC improved glucose tolerance in this mouse model by increasing beta-cell volume, primarily through accelerated neogenesis from ductal lining cells.

Aquaporin adipose, a putative glycerol channel in adipocytes

Adipose tissue is a major site of glycerol production in response to energy balance. However, molecular basis of glycerol release from adipocytes has not yet been elucidated. We recently cloned a novel member of the aquaporin family, aquaporin adipose (AQPap), which has glycerol permeability. The current study was designed to examine the hypothesis that AQPap serves as a glycerol channel in adipocytes. Adipose tissue expressed AQPap mRNA in high abundance, but not the mRNAs for the other aquaglyceroporins, AQP3 and AQP9, indicating that AQPap is the only known aquaglyceroporin expressed in adipose tissue. Glycerol release from 3T3-L1 cells was increased during differentiation in parallel with AQPap mRNA levels and suppressed by mercury ion, which inhibits the function of AQPs, supporting AQPap functions as a glycerol channel in adipocytes. Fasting increased and refeeding suppressed adipose AQPap mRNA levels in accordance with plasma glycerol levels and oppositely to plasma insulin levels in mice. Insulin dose-dependently suppressed AQPap mRNA expression in 3T3-L1 cells. AQPap mRNA levels and adipose glycerol concentrations measured by the microdialysis technique were increased in obese mice with insulin resistance. Accordingly, negative regulation of AQPap expression by insulin was impaired in the insulin-resistant state. Exposure of epinephrine translocated AQPap protein from perinuclear cytoplasm to the plasma membrane in 3T3-L1 adipocytes. These results strongly suggest that AQPap plays an important role in glycerol release from adipocytes.

Assessment of benzydamine N-oxidation mediated by flavin-containing monooxygenase in different regions of rat brain and liver using microdialysis

N-Oxidation of benzydamine (BZY) mediated by flavin-containing monooxygenase (FMO) was evaluated by microdialysis in vivo in different regions of rat brain and liver. The probe was implanted into local regions of the brain, such as the olfactory bulb, cerebral cortex, corpus striatum, hippocampus and cerebellum, or the hepatic lobe. By perfusing BZY via the probe, BZY N-oxide was identified in the dialysate. The estimated concentrations of BZY N-oxide in extracellular fluid were almost the same as those in the olfactory bulb, hippocampus and cerebral cortex, half the concentration in the hepatic lobe; however, the concentration in the corpus striatum was lower and that in the cerebellum was higher than in the other regions. These results demonstrate that the extracellular concentration of BZY N-oxide formed in vivo was unexpectedly high in every brain region.

Flavin-containing monooxygenase mediated metabolism of benzydamine in perfused brain and liver

Benzydamine (BZY) N-oxidation mediated by flavin-containing monooxygenase (FMO) was evaluated in perfused brain and liver. Following 20 min of perfusion with modified Ringer solution, the infusion of BZY into brain or liver led to production of BZY N-oxide. BZY N-oxide, a metabolite of BZY oxidized exclusively by FMO, was mostly recovered in the effluent without undergoing further metabolism or reduction back to the parent substrate. The BZY N-oxide formation rate increased as the infusion concentration of BZY increased both in perfused brain and perfused liver. BZY N-oxidation activities in perfused rat brain and liver were 4.2 nmol/g brain/min and 50 nmol/g liver/min, respectively, although the BZY N-oxidation activity in brain homogenates was one 4000th that in liver homogenates. This is the first study of FMO activity in brain in situ.

Demonstration of two different processes of beta-cell regeneration in a new diabetic mouse model induced by selective perfusion of alloxan

To clarify the regeneration process of pancreatic beta-cells, we established a new mouse model of diabetes induced by selective perfusion of alloxan after clamping the superior mesenteric artery. In this model, diabetes could be induced by the destruction of beta-cells in alloxan-perfused segments, while beta-cells in nonperfused segments were spared. Intraperitoneal glucose tolerance tests showed glucose intolerance, which gradually ameliorated and was completely normalized in 1 year with a concomitant increase of insulin content in the pancreas. Histological examination showed neo-islet formation in the alloxan-perfused segment and the proliferation of spared beta-cells in the nonperfused segment. In the alloxan-perfused segment, despite a marked reduction of islets in size and number at an early stage, both the number of islets, including islet-like cell clusters (ICCs), and the relative islet area significantly increased at a later stage. Increased single beta-cells and ICCs were located in close contact with duct cell lining, suggesting that they differentiated from duct cells and that such extra-islet precursor cells may be important for beta-cell regeneration in beta-cell-depleted segment. In addition to beta-cells, some nonhormone cells in ICCs were positive for nuclear insulin promoter factor 1, which indicated that most, if not all, nonhormone cells positive for this factor were beta-cell precursors. In the nonperfused segment, the islet area increased significantly, and the highest 5-bromo-2-deoxyuridine-labeling index in beta-cells was observed at day 5, while the number of islets did not increase significantly. This indicated that the regeneration of islet endocrine cells occurs mostly through the proliferation of preexisting intra-islet beta-cells in the nonperfused segment. In conclusion, the regeneration process of beta-cells varied by circumstance. Our mouse model is useful for studying the mechanism of regeneration, since differentiation and proliferation could be analyzed separately in one pancreas.

Circadian rhythm in the cerebral resistance to hypoxia in mice

The cerebral resistance to hypoxia in mice was investigated by measuring the survival time under both hypobaric and normobaric hypoxic conditions. In the ad libitum fed mice, there was a circadian variation in the survival time that was longer during the light period than during the dark period under hypobaric hypoxic conditions. The survival time under normobaric hypoxic conditions also exhibited a similar circadian variation in the ad libitum fed mice, whereas the rhythm of the survival time was completely reversed by the restriction of food presentation (9:00-15:00). These findings suggest that there is a circadian rhythm in the cerebral resistance of mice to hypoxia, which can be shifted by the time of food presentation. Furthermore, regression analyses revealed a negative correlation between the survival time of mice exposed to hypoxia and body temperature, and blood glucose levels. These indicate that the cerebral resistance to hypoxia was intimately associated with body temperature and blood glucose that both show a circadian rhythm in mice.

Circadian periodicity in the duration of decapitation-induced gasping in mice

The circadian variation of decapitation-induced gasping was investigated by measuring the gasping duration of isolated mouse head after decapitation under both normal and restricted feeding conditions. In the normally fed mice, there was a circadian periodicity in the gasping duration: it was longer during the light period than during the dark period. The circadian periodicity was completely reversed by the restriction of food. The circadian periodicity of the gasping duration were conversely parallel to those of body temperature in both normal and feeding restricted mice, and regression analysis revealed a negative correlation between the gasping duration and body temperature. Furthermore, pentobarbital and ethanol, agents that caused hypothermia, markedly prolonged the gasping duration. These findings suggest that there is a circadian periodicity in the brain reactivity after complete ischemia, which may be associated with the changes of body temperature.

Brain glutathione and the anti-hypoxic effect of glutathione depletors in mice

The anti-hypoxic effect (assessed by a standard hypoxia survival test) 3 hr after 2-cyclohexene-1-one (CHX) was completely abolished by injections of L-cysteine after CHX. Under these conditions, brain GSH was depleted to about 50% of the control level in CHX-treated mice and recovered to about 80% of control level following L-cysteine post-treatment. However, D-cysteine could not cause such effects. Intracerebroventricular injection of CHX, which caused a selective depletion of brain GSH, produced an anti-hypoxic effect. Thus, the anti-hypoxic effect may be related to the decrease of brain GSH levels.

2-cyclohexene-1-one-induced hyperglycemia in the mice

2-Cyclohexene-1-one (CHX) dose-dependently caused the elevation of blood glucose levels in both fed and fasted mice. Adrenalectomy considerably prevented the elevated blood glucose with CHX, and plasma adrenaline assays revealed about a three- to fifteen-fold rise after CHX treatment. These findings indicate that the CHX-induced hyperglycemia may be largely mediated by adrenaline released from the adrenal medulla.

Anti-hypoxic effect of glutathione depletors

The effect of various reduced glutathione (GSH) depletors on the survival time under normobaric and hypobaric hypoxia was examined in mice. The survival time was markedly prolonged in mice treated with glutathione S-transferase substrate, 2-cyclohexene-1-one (50-100 mg/kg, ip) and phorone (100-250 mg/kg, ip). The anti-hypoxic effect lasted for at least 3 hr and the maximum effect was found 0.5 hr after injection. Further, both compounds significantly elevated blood glucose levels 0.5-1 hr after treatment. The extent of the elevated blood glucose was nearly comparable to that of the mice treated with glucose (1-2 g/kg, ip), which was found to possess an anti-hypoxic effect. However, a GSH synthesis inhibitor, buthionine sulfoximine, could cause neither a prolongation of survival time of hypoxic mice nor an elevation of blood glucose. Moreover, unlike the depletion of hepatic GSH, brain GSH was markedly decreased by 2-cyclohexene-1-one and phorone, but not by buthionine sulfoximine. These findings suggest that the elevated blood glucose may involve in one of the mechanisms of the anti-hypoxic effect of 2-cyclohexene-1-one and phorone. A relationship between the anti-hypoxic effect and the depletion of brain GSH was also discussed.

Methods for depleting brain glutathione

To search for a technique to deplete reduced glutathione (GSH) in brain, the influence of various types of compounds on brain GSH levels was investigated in mice. Of the compounds tested, cyclohexene-1-one, cycloheptene-1-one and diethyl maleate were shown to be potent GSH depletors in brain as well as in liver. The depletion of cerebral GSH ranged about 40-60% of control levels at 1 and 3 hr after intraperitoneal injection. Cyclohexene, cycloheptene, phorone, acetaminophen, and benzyl chloride caused mild depletion of cerebral GSH, but buthionine sulfoximine did not alter cerebral GSH levels. Further, intracerebroventricular injection of cyclohexene-1-one and cycloheptene-1-one caused depletion of brain GSH to about 60-80% of control levels at 1 hr after injection, and the effects persisted for at least 6 hr. Under these conditions, hepatic GSH was not altered. These results demonstrated that cyclohexene-1-one and cycloheptene-1-one can cause not only a marked depletion of brain GSH by systemic administration, but also depletion of cerebral GSH by intracerebroventricular injection by virtue of being water-soluble compounds. Thus, methods for depleting brain GSH employing both compounds are available for exploring possible functions of cerebral GSH in in vivo systems.

Impaired catecholamine secretion as a cause of diabetic autonomic neuropathy

Human and animal studies were performed to investigate the causes of diabetic autonomic neuropathy. Human diabetics, with and without autonomic neuropathy, were measured for plasma catecholamine response to insulin hypoglycemia and for urinary catecholamine excretion. In streptozotocin-diabetic rats, plasma catecholamine response and tissue catecholamine concentrations were measured at various stages of the disease. As the duration of the diabetic state lengthens in rats, there is a time-proportional stepwise decrease in plasma catecholamine response. This is similar to the clinical course observed in human diabetics, which also includes a reduction of catecholamine excretion after the appearance of autonomic neuropathy. After 6 weeks of diabetes, rat tissue is found to have an increased concentration of catecholamines; this may represent a compensatory reaction to the difficulties of secretion. At 13 weeks of diabetes, tissue catecholamine concentrations return to almost normal, when plasma responses have disappeared. These results suggest that the impaired secretion of catecholamines in diabetics may be a cause of diabetic autonomic neuropathy.

A novel gene activated in regenerating islets

Administration of poly(ADP-ribose) synthetase inhibitors such as nicotinamide to 90% depancreatized rats induces regeneration of pancreatic islets, thereby ameliorating the surgical diabetes (Yonemura, Y., Takashima, T., Miwa, K., Miyazaki, I., Yamamoto, H., and Okamoto, H. (1984) Diabetes 33, 401-404). In screening the regenerating islet-derived cDNA library, we came across a novel gene encoding a 165-amino acid protein. The gene was expressed in regenerating islets but not in normal pancreatic islets, insulinomas, or regenerating liver. In 90% depancreatized and nicotinamide-injected rats, the expression of the gene was increased 1 month after the partial pancreatectomy and reached a peak 3 months after the operation. The increase in expression of the gene was temporally correlated with the increase in size of regenerating islets and the decrease in urinary glucose level. The gene was also found to be activated in hyperplastic islets of aurothioglucose-treated mice. Thus, the expression of the gene in both regenerating and hyperplastic islets suggests possible roles for this gene in replication, growth, and maturation of islet beta-cells. We also found that a human pancreas-derived cDNA library contained a homologue to the gene.

Effects of beta-lactam antibiotics and N-methyltetrazolethiol on the alcohol-metabolizing system in rats

The disulfiram-like effect of various beta-lactam antibiotics containing N-methyltetrazolethiol (NMTT) on the alcohol-metabolizing system was studied using rats. Their administration caused decreased activities in low Km aldehyde dehydrogenase (ALDH) and acetaldehyde oxidation in the liver, with marked depression from several hours to 2 days after the treatment. Blood acetaldehyde level increased markedly when ethanol was administered 18-24 hr after pretreatment with antibiotics. A similar time course change in the effect was obtained when disulfiram was administered. The following results obtained in the present study indicate that the disulfiram-like effect associated with these antibiotics was not mediated by the whole molecular structures of these drugs: Firstly, the antibiotics were eliminated rapidly from the plasma and liver, and the disulfiram-like effect was followed by a disappearance of the drugs. Secondly, the concentration of antibiotics required to inhibit mitochondrial low Km ALDH activity in vitro was very high compared with their liver concentration. Thirdly, rapid onset of disulfiram-like effects occurred after administration of NMTT itself, and a pronounced elevation of blood acetaldehyde level was observed when ethanol was administered 3-5 hr after the NMTT injection. Fourthly, almost the same amounts of NMTT were released in the body after the intravenous administration of various NMTT-containing antibiotics, as judged by the urinary excretion. These results suggest that the disulfiram-like effect of beta-lactam antibiotics is mediated by NMTT released from them.

Age related changes of N-acetyl-beta-D-glucosaminidase and L-alanine aminopeptidase in mouse kidney, urine and plasma

Age and sex dependent differences of N-acetyl-beta-D-glucosaminidase (NAG) and L-alanine aminopeptidase (AAP) activities in kidney, urine and plasma of male and female mice were studied. The sex difference in NAG activity appeared between 27 and 38 days of age with the manifestation of significant differences in body weight and kidney growth. NAG activity in male kidneys was 3-fold that in females and its urinary level in mature males was over 10-fold higher. Androgenic regulation was found not only in the NAG contents in the kidneys and in the urinary excretion but also in the plasma NAG level, which showed higher in females. On the other hand, AAP activity in kidney, urine and plasma did not show much sex differences. Age related changes in AAP activity were not found except in the kidney and marked androgenic regulation was also not found in AAP. These results indicate that NAG and AAP, which are both urinary enzymes used as indicators of renal lesions, may be regulated differently.

Ultrastructural and immunocytochemical aspects of lymphocytic submandibulitis in the non-obese diabetic (NOD) mouse

The submandibular glands of female non-obese diabetic (NOD) mice (22-26 weeks of age) were studied by light and electron microscopy. Mononuclear cells consisting mostly of lymphocytes were recognized in and among the acini and secretory ducts. Some parts of the secretory ducts and mucous acini surrounded by lymphocytes showed destructive changes. In the secretory ducts lymphocytes invaded the duct epithelial lining and the duct lumen was occluded by these cells. The duct epithelial cells in such lesions were extremely distorted and tonofilament bundles running in various directions were present in the cytoplasm. Lymphocytes were in close contact with the duct epithelial cells. In the mucous acini some acinar cells, which appeared to be compressed by the infiltrating lymphocytes, showed degenerative changes. Immunocytochemical study revealed that both T- and B-lymphocytes were involved, T-lymphocytes tending to occupy the center of the infiltrate, while B-lymphocytes occupied the periphery. Although autoantibody against duct epithelial cells was identified, damage to duct epithelial cells was not correlated with the presence of this antibody. The morphological changes in the submandibular gland of the NOD mouse are very similar to those reported in the salivary gland of patients with Sjögren's syndrome.

A comparative study on the effects of disulfiram and beta-lactam antibiotics on the acetaldehyde-metabolizing system in rats

Several beta-lactam antibiotics, especially those containing N-methyltetrazolylthiomethyl groups at the 3-position of the cephalosporin nucleus, affect the alcohol-metabolizing system in rats. These effects were compared those with disulfiram, well-known as a potent inhibitor of aldehyde dehydrogenase (ALDH). Both disulfiram and antibiotics containing the N-methyltetrazolylthiomethyl group inhibited both mitochondrial low Km ALDH and acetaldehyde oxidation in rat livers. The high Km ALDH and alcohol dehydrogenase activities in livers were not affected by these treatments. When ethanol was given to rats pretreated with disulfiram or these antibiotics, the blood acetaldehyde concentration increased markedly concomitant with a decrease in activity of the low Km ALDH. Administration of N-methyltetrazolethiol alone suppressed the low Km enzyme activity and also increased the blood acetaldehyde level; both effects were pronounced and observed several hours after administration. beta-Lactam antibiotics without N-methyltetrazolethiol in their molecule did not affect the liver mitochondrial enzyme activity or the blood acetaldehyde level.

Amitrole: strain differences in morphological response of the liver following subchronic administration to mice

Strain differences in the induction of hepatocellular preneoplastic lesions by amitrole were examined in NOD, ICR and DS mice. Amitrole was administered to mice in drinking water at a dose of 1% for 6 months. After 3 months, hyperplastic nodules (HN) and severe fibrosis were prominent in NOD mice but not in other strains. On examination at 6 months, both number and size of HN were greatest in the NOD strain. Furthermore, a hepatocellular carcinoma was found in a NOD mouse, suggesting that this strain is more susceptible to amitrole-induced hepatocarcinogenesis than are ICR or DS mice.

Prevention of type I diabetes in nonobese diabetic mice by allogenic bone marrow transplantation

An animal model [the nonobese diabetic (NOD) mouse] for type I diabetes features a striking infiltration of T cells into the pancreatic islets. This infiltration selectively destroys beta cells. Most of the T cells are Lyt-1+, but some are Lyt-2+,3+. Transfer experiments using parabiosis revealed that insulitis can be transferred within 2 weeks after parabiosis to immunoincompetent thymectomized mice. When NOD mice (6 mo old) were irradiated and reconstituted with bone marrow cells from young BALB/c nu/nu mice (less than 2 mo old), the NOD mice exhibited neither insulitis nor overt diabetes. Deposits of immunoglobulin in mesangial areas of the glomeruli disappeared within 3 mo after bone marrow transplantation in such irradiated allogeneic bone marrow reconstituted mice. Assays for immunological functions, including mitogen response and mixed lymphocyte reaction, revealed that both T- and B-cell functions were increased in NOD mice with overt diabetes. NOD mice reconstituted with BALB/c nu/nu bone marrow cells displayed normal T- and B-cell functions. The newly developed T cells in the allogeneic bone marrow recipients are tolerant to cells with both donor- and host-type major histocompatibility complex determinants. These results suggest that bone marrow transplantation may ultimately be developed as a component of a strategy to be employed for treatment of type I diabetes in humans.

Insulin and glucagon in spontaneously diabetic non-obese mice

To investigate the role of glucagon in the development of diabetes mellitus, spontaneously diabetic non-obese mice were studied before (group 1) and after the onset of diabetes mellitus (group 2). In group 1, fasting blood glucose and insulin in plasma and pancreas did not differ significantly, while plasma glucagon was elevated (48.9 +/- 10.4 versus control 18.6 +/- 6.0 pmol/l). In group 2, the insulin content of plasma and the pancreas were markedly reduced, whereas plasma glucagon was elevated (180.9 +/- 59.1 pmol/l). When diabetic mice were treated with insulin for 4 weeks (group 3), plasma glucagon was markedly reduced compared with that of group 2 (30.3 +/- 9.0 pmol/l). In group 1, glucagon and glucagon-like immunoreactivity of the intestine were reduced. The glucagon content of the intestine was elevated in group 2. Group 3 elicited increased contents of gastric glucagon as well as intestinal glucagon-like immunoreactivity. We conclude that, in addition to insulin deficiency, hypersecretion of glucagon might contribute to the development and clinical course of diabetes mellitus in the non-obese diabetic mouse.

Abnormalities in plasma catecholamine response and tissue catecholamine accumulation in streptozotocin diabetic rats: a possible role for diabetic autonomic neuropathy

Plasma catecholamine levels, determined by high performance liquid chromatography, were elevated in response to blood withdrawal in normal rats. Such a response was also observed in streptozotocin diabetic rats 2 and 6 weeks after disease onset, but was no longer seen at 13 weeks. Tissue (adrenal, heart, skin, kidney) catecholamine levels in diabetic rats were increased at 6 weeks as well as at 13 weeks. These abnormalities were corrected by insulin treatment in at least a part of diabetic rats. The present data suggest that there might be a catecholamine accumulation, which is later accompanied with an impairment of catecholamine secretion, in diabetic rats, and they gave a basis for an inference that similar changes might play some role in the pathogenesis of diabetic autonomic neuropathy in man.

Sex difference of N-Acetyl-beta-D-glucosaminidase activity in the kidney, urine, and plasma of mice

N-Acetyl-beta-D-glucosaminidase (NAG) activities in urine, kidney, and plasma were compared in an age-matched group of male and female ds mice. In males, the NAG activity in the kidney was significantly higher (p less than 0.001), and the urinary NAG activity (unit/g creatinine) was 8-fold higher than those for females, while plasma NAG levels were significantly lower (p less than 0.001). These findings indicate that when using urinary NAG activity to detect drug nephrotoxicity in mice, the different basal levels between males and females should be considered before drug administration.

Renin-angiotensin system and prostacyclin biosynthesis in streptozotocin diabetic rats

The relationship between the renin-angiotensin system (RAS) and prostacyclin (PGI2) biosynthesis was studied in experimental diabetic rats. The group with diabetes induced by streptozotocin (STZ, 3.3 mmol/kg i.v.) showed prolonged hypertension, and plasma renin activity decreased markedly from 8.4 +/- 0.7 to 2.4 +/- 0.3 and 1.2 +/- 0.3 ng angiotensin I/ml per h at 2 and 8 weeks after STZ treatment. Plasma PGI2, determined as 6-keto-PGF1 alpha, decreased significantly at 8 weeks, with the values for the STZ-treated and control groups being 1490 +/- 99 and 2210 +/- 90 pg/ml, respectively. Significant suppression of renin release from renal cortical slices was observed at 8 weeks in the diabetic group, although no significant change was found in the renal renin content when compared with that of the controls. The release of PGI2 from the renal medullary slices of the diabetic group was suppressed at 2 and 8 weeks, with the suppression in aorta and renal cortical slices being apparent only at 8 weeks. These results indicate that suppression of the RAS may be related to PGI2 biosynthesis in diabetes mellitus.

Decreased response of plasma catecholamine to stress in diabetic rats

Previously we reported that the heart norepinephrine concentration was markedly increased in diabetic rats. To further study the relationship between a disturbance in the autonomic nervous system and catecholamine metabolism in diabetes mellitus, the plasma catecholamine response to stress and catecholamine concentration of heart and adrenals were measured. Wistar male rats were made diabetic by streptozotocin and kept for 13 weeks. A silicon catheter was placed in the superior V. cava 1 week prior to the experiment. Insulin was injected subcutaneously for 3 days once daily. After an overnight fast and without anesthesia, 1 ml of blood, a control sample, was obtained and then the animals were exsanguinated. The blood was mixed with 1 mM EGTA at a final concentration and centrifuged. The tissue was homogenized with 0.4 N perchloric acid containing 1 mM EGTA and centrifuged at 10,000 x g for 20 minutes. Catecholamines were determined by high performance liquid chromatography. Normal rats responded to blood withdrawal stress, and plasma catecholamines were markedly increased, but almost no increase or an actual decrease was observed in diabetic rats. These abnormal responses were improved by insulin treatment. Heart norepinephrine was increased significantly in the diabetic rats compared with the control rats and was reduced significantly by insulin injections. Adrenal epinephrine was also significantly increased in the diabetic rats compared with the control rats, but was not significantly reduced by insulin. These result suggest a possible disturbance of catecholamine secretion in the diabetic rats.

Pancreatic somatostatin contents in spontaneously diabetic KK and non-obese diabetic (NOD) mice

Alterations in the somatostatin (SRIF)-, insulin- and glucagon-containing cells were examined in two strains of spontaneously diabetic mice, KK and newly inbred non-obese diabetic (NOD) mice, using radioimmunoassay and immunohistochemical methods. The total pancreatic content and concentration of SRIF was decreased in male KK mice compared to their male controls aged 12-18 weeks. These results were consistent with the immunohistochemical findings. Pancreatic glucagon concentration and number of glucagon-containing cells were also decreased in KK mice, but pancreatic insulin concentrations were increased in KK mice. On the other hand, NOD mice aged 12-38 weeks within 15 days after onset of diabetes had increased concentrations of pancreatic SRIF. The pancreatic islets in NOD mice were decreased both in number and in size and were characterized by lymphocyte infiltration. SRIF-containing cells occupied the major part of the endocrine cells of the islets. Insulin-containing cells significantly decreased in number, but the number of glucagon-containing cells was fairly well preserved. These results and previous work concerning obob and dbdb mice indicate a parallel relationship between pancreatic SRIF and glucagon. The pancreatic glucagon thus as well as the pancreatic insulin may be an important determinant of pancreatic SRIF concentration in these diabetic animals.

Increased norepinephrine content in diabetic rat heart

In an attempt to clarify the mechanism of cardiac neuropathy in diabetes mellitus, Wister male rats were made diabetic by streptozotocin injection for 11 to 13 weeks, and catecholamine concentrations of hearts were determined by high performance liquid chromatography. No apparent histological changes were found in hearts and kidneys of any group of rats. Controls used were age-matched normal rats and Goldblatt-hypertensive rats, because streptozotocin induced diabetic rats appeared to be significantly hypertensive. Heart norepinephrine concentrations of diabetic rats and diabetic-Goldblatt-hypertensive rats were markedly higher (8,380 +/- 300 pmol/g tissue and 6,980 +/- 390, respectively) compared with those of controls and Goldblatt-hypertensive rats (2,700 +/- 470 and 2,010 +/- 300, respectively). These results suggest some disturbances in catecholamine secretion in diabetic hearts before typical microangiopathic changes take place.

Biotransformation of coumarin derivatives (1). 7-alkoxycoumarin O-dealkylase in liver microsomes

The in vitro metabolic fate of 7-alkoxycoumarin was studied using liver microsomes. Microsomal enzyme catalyzed dealkylation of 7-alkoxycoumarin to 7-hydroxycoumarin in the presence of NADPH and molecular oxygen as cofactors was found to be one of the metabolic pathways. The metabolite 7-hydroxycoumarin was further metabolized to unidentified metabolite(s) in the presence of NADPH and O2 at a very slow rate, while the formation of the conjugate of 7-hydroxycoumarin with glucuronic acid was observed in the presence of UDPGA. Microsomal 7-alkoxycoumarin O-dealkylase activity was altered by the substitution of the alkyl group of the substrate, and the substitutions to either an O-propyl or an O-butyl group resulted in a decrease of the enzyme activity. Species differences were observed in the substrate specificity of microsomal O-dealkylation. The O-dealkylase activities in rat liver microsomes were stimulated by pretreatment of the animals with phenobarbital, regardless of the O-alkyl substituent at the 7 position of the coumarin ring. On the other hand, pretreatment with 3-methylcholanthrene or beta-naphthoflavone resulted in marked increase of O-deethylation. O-depropylation and O-debutylation activities, but not of O-demethylation activity. Pretreatment of animals with beta-naphthoflavone also resulted in remarkable stimulation of 7-hydroxycoumarin-glucuronide formation by the microsomal enzyme, while the conversion of 7-hydroxycoumarin to unidentified metabolite(s) was activated by the pretreatment of rats with only phenobarbital. The O-dealkylation activities in liver microsomes from intact and phenobarbital pretreated rats were inhibited markedly by the addition of hexobarbital to the incubation mixture, but no inhibition was observed with alpha-naphthoflavone. On the other hand, the O-dealkylation activities in microsomes from beta-naphthoflavone-pretreated rats were inhibited remarkably by alpha-naphthoflavone. These results confirmed that several microsomal enzymes, including the cytochrome P-450's and UDP-glucuronyltransferase, participate in the biotransformation of 7-alkoxycoumarin, and these enzymes are regulated differently by inducers.

Semisynthesis and biological properties of the [B24-leucine]-, [B25-leucine[- and [B24-leucine, B25-leucine]-analogues of human insulin

Trypsin-catalyzed coupling of porcine desoctapeptide-insulin with synthetic octapeptides produced the [LeuB24]- (I), [LeuB25]- (II) and [LeuB24, LeuB25]- (III)analogues of human insulin. I, II and III displayed respectively 20--30%, 1--2% and 0.5% of the receptor binding activity of the normal hormone. Biological activities of these analogues seemed to be proportional to their binding potencies when assayed in vitro, while in an in vivo assay analogue I was fully active and II exhibited 10--20% of normal activity. III was less active than II in all assays tested.

The effects of parabiosis on serum and kidney glycosidase activities in spontaneously diabetic mice

Spontaneously diabetic non-obese mice of the ICR strain were newly inbred in Shionogi laboratory, Japan. Animals became diabetic suddenly, more frequently and severely in females. Blood glucose levels were 452 +/- 73 mg/100 ml with serum insulin levels of less than 1.0 microU/ml in the fed state. Parabiosis with normal control ICR mice for 2 weeks decreased the blood glucose level to 260 +/- 51 mg/100 ml (P less than 0.01) and resulted in serum insulin levels of 46.0 +/- 18.0 microU/ml (P less than 0.01). Kidney homogenate beta-N-acetylglucosaminidase and beta-galactosidase activities were reduced in diabetic mice (42% and 44% decreases respectively) (P less than 0.025 and P less than 0.001), and restored almost to normal after 2 weeks of parabiosis. Renal alpha-mannosidase activity was decreased 43% (P less than 0.001) in the diabetic mice but unaffected by parabiosis. Serum beta-N-acetylglucosaminidase, beta-galactosidase and alpha-glucosidase activities were significantly increased in diabetic mice (179%; 233% and 58% increase respectively) (P less than 0.005, P less than 0.001 and P less than 0.001), and returned to normal with parabiosis.

Breeding of a non-obese, diabetic strain of mice

A female mouse spontaneously exhibiting polyuria and glucosuria accompanied by rapid weight loss waa found in one of two sublines derived from the CTS mice. Eight mating pairs were made using its offspring and selection was performed for both spontaneous diabetes and reproductive ability. After six generations of the selective breeding the diabetic (nod) and the control (non) lines were established. A marked sex difference was observed in the incidence of diabetic symptoms in the nod mouse. The cumulative incidence of the onset up to 30 weeks of age was 80% in females and less than 20% in males. The onset of diabetes was abrupt in both sexes, and spontaneous remission was not observed. However, daily administration of insulin induced an increase of body weight and a prolongation of life span. Diabetic symptoms are biochemically characterized by polyuria, polydipsia, hyperglycemia, glucosuria and hypercholesteremia. Pathological examination revealed a high frequency of lymphocyte infiltration around and/or into the Langerhans' islet. It was observed even at the prediabetic stage over five weeks of both sexes. The number and size of the islets were markedly reduced in the overt diabetic mice. Although the mechanism of the pathogenesis is not clear yet, the nod mouse may be a useful animal model for investigating the human juvenile type diabetes.

Hepatic aminopyrine N-demethylase system: further studies of assay procedure

Rat hepatic aminopyrine N-demethylase activity was measured by detecting the amount of formaldehyde produced from aminopyrine. Some optimal conditions for the N-demethylation were determined using both isolated microsomes and whole homogenates, and the standard assay method is described. Formaldehyde production from the substrate by microsomal enzyme system was linear to the amount of microsomes added during 3 min reaction time, whereas long-time incubation caused a decrease in the apparent activity of aminopyrine N-demethylation. The N-demethylase activity observed in normal rat liver homogenate was quite similar to that in microsomes when the activity was expressed on the basis of cytochrome P-450 as molecular activity. Pretreatment of animals with typical inducers, phenobarbital and 3-methylcholanthrene, resulted in alteration of the aminopyrine N-demethylase system, which was detectable in both microsomes and whole homogenates.

Electron transport systems of lung microsomes and their physiological functions. Enzymic hydroxylation of aniline and steroids

1. The hydroxylation of aniline by rabbit lung microsomes to rho-aminophenol required oxygen and NADPH, and was inhibited by menadione, ferricytochrome c and carbon monoxide. 2. NADH was a less effective electron donor than NADPH in this reaction, but its addition significantly increased the yield of rho-aminophenol formed in the presence of NADPH. 3. 4,16-Androstadien-3-one and 3beta-hydroxy-5-androsten-17-one were also metabolized by lung microsomes to the same products as are formed by hepatic microsomes.

Studies on cyclophosphamide metabolites and their related compounds. 2. Preparation of an active species of cyclophosphamide and related compounds

A synthetic study was made on the active metabolite of cyclophosphamide. Ozonolysis of O-(3 butenyl)-N,N-bis(2-chloroethyl)phosphorodiamidate, prepared by reaction of POC13 with 3-buten-1-ol followed by treatment with N,N-bis(2-chloroethyl)amine (nor mustard) and NH3, afforded 2-[bis(2-chloroethyl)amino]-4-hydroperoxytetrahydro-2H-1, 3,2-oxazaphosphorine 2-oxide (4-hydroperoxycyclophosphamide). Deoxygenation of 4-hydroperoxycyclophosphamide by triphenylphosphine yielded 4-hydroxycyclophosphamide in a pure crystalline state. These products exhibited high cytostatic activity in both in vitro and in vivo experiments. The results give confirmatory evidence for the hypothesis that C4-hydroxylation on the 1,3,2-oxazaphosphorinane ring of cyclophosphamide is necessary for its activation.