In vitro metabolism of fenthion and fenthion sulfoxide by liver preparations of sea bream, goldfish, and rats.

The in vitro metabolism of fenthion and its sulfoxide (fenthion sulfoxide) in sea bream (Pagrus major) and goldfish (Carassius auratus) was investigated and compared with that in rats. Fenthion was oxidized to fenthion sulfoxide and the oxon derivative, but not to its sulfone, in the presence of NADPH by liver microsomes of sea bream, goldfish, and rats. These liver microsomal activities of the fish were lower than those of rats but were of the same order of magnitude. The NADPH-linked oxon- and sulfoxide-forming activities of liver microsomes of the fish and rats were inhibited by SKF 525-A, metyrapone, alpha-naphthoflavone, and carbon monoxide. The oxidizing activity to fenthion sulfoxide was also inhibited by alpha-naphthylthiourea. Several cytochrome P450 isoforms and flavin-containing monooxygenase 1 exhibited these oxidase activities. Fenthion sulfoxide was reduced to fenthion with liver cytosol of the fish and rats upon addition of 2-hydroxypyrimidine, N(1)-methylnicotinamide, or butyraldehyde, each of which is an electron donor of aldehyde oxidase, under anaerobic conditions. The activity was inhibited by menadione, beta-estradiol, and chlorpromazine, which are inhibitors of aldehyde oxidase. The activities in the fish livers were similar to those of rat liver. Aldehyde oxidase purified from the livers of sea bream and rats exhibited the reducing activity. Thus, fenthion and fenthion sulfoxide are interconvertible in fish and rats through the activities of cytochrome P450, flavin-containing monooxygenase, and aldehyde oxidase.     

Pelvic insufficiency fractures in postmenopausal woman with advanced cervical cancer treated by radiotherapy.

PURPOSE: To assess the predisposing factors and clinical characteristics of pelvic insufficiency fractures (PIF) in postmenopausal women with pelvic irradiation. MATERIAL AND METHODS: A total 335 postmenopausal patients with cervical cancer of the intact uterus treated with radiation therapy between 1983 and 1998 were reviewed. Total external dose was delivered between 45 and 50.4 Gy with parallel opposed anteroposterior portals. Total brachytherapy dose at point A was delivered between 10 and 36 Gy. PIF were diagnosed by bone scintigraphy and confirmed by computed tomography. The cumulative incidence of symptomatic PIF was estimated by actuarial methods. Potential risk factors (age, weight, type II diabetes, delivery, menopause, total external dose, total brachytherapy dose) were assessed. RESULTS: Fifty-seven (17.0%) of 335 patients were diagnosed as having PIF. Forty-seven patients were symptomatic and ten were asymptomatic. Parameters carrying a significant association with PIF were body weight 49 kg or below (P=0.044) in stepwise logistic regression analysis. The cumulative incidence of symptomatic PIF at 5 years was 17.9% calculated by the Kaplan-Meier method. A body weight of 49 kg or below and more than three deliveries were identified as having a significant effect on symptomatic PIF in univariate analysis (P=0.021, P=0.003, log-rank test) and Cox life table regression analysis (P=0.038, P=0.013). Five patients required narcotic agents and eight patients required hospital admission. CONCLUSIONS: We should consider reducing the dose contribution to the sacrum and sacroilac joints, without underdosing the tumor, especially in postmenopausal women with many deliveries or low body weight.     

Adoptive transfer of nuclear factor-kappaB-inactive macrophages to the glomerulus

BACKGROUND: Macrophages have been regarded as "blackguards" in the generation of glomerular injury. However, it is still unclear what kind of cellular machinery is responsible for their pathogenic actions. To explore this issue, this investigation aims at developing a novel strategy using adoptive transfer of "loss-of-function" macrophages to the glomerulus. As a prototypal investigation, this study examines a role for nuclear factor-kappaB (NF-kappaB) in effector actions of macrophages within the glomerular microenvironment. METHODS: NF-kappaB-inactive macrophages, NIKMACNR, were created by transduction of NR8383 rat macrophages with retrovirus encoding a super-repressor mutant of IkappaBalpha, IkappaBalphaM. The effector functions of NIKMACNR cells on resident cells were evaluated by coculture, cross-feeding, and in vivo macrophage transfer. RESULTS: Rat mesangial cells cocultured with control macrophages showed abundant expression of activation markers, including monocyte chemoattractant protein-1, stromelysin, and gelatinase B. In contrast, coculture with NIKMACNR macrophages induced only modest gene expression. Similarly, culture medium conditioned by activated, control macrophages triggered mesangial cells and isolated glomeruli to express the activation markers, whereas the stimulatory effect was not observed in medium conditioned by NIKMACNR macrophages. To evaluate effector actions of NIKMACNR macrophages in the glomerulus, control macrophages and NIKMACNR cells were transferred into normal rat glomeruli via renal artery injection. After the transfer of control macrophages, substantial induction of the activation marker stromelysin was observed in resident glomerular cells. This induction was dramatically diminished in the glomeruli transferred with NIKMACNR macrophages. CONCLUSIONS: Inactivation of NF-kappaB in macrophages effectively disrupted paracrine, stimulatory loops from macrophages to resident glomerular cells. A combination of "loss-of-function" strategies with the technique for adoptive cell transfer is thus useful to explore pathophysiologic roles for certain machinery of macrophages within the glomerulus.     

Anti-apoptotic effect of quercetin: intervention in the JNK- and ERK-mediated apoptotic pathways

BACKGROUND: Bioflavonoid quercetin inhibits hydrogen peroxide (H2O2)-induced apoptosis via intervention in the activator protein 1 (AP-1)-mediated apoptotic pathway. In this report, we investigated molecular events involved in the anti-apoptotic effect of quercetin, focusing especially on its effects on the family of mitogen-activated protein (MAP) kinases. METHODS: Cultured mesangial cells were exposed to H2O2, and activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERKs), and p38 MAP kinase was evaluated in the presence or absence of quercetin. Using pharmacological and genetic inhibitors, the roles for individual MAP kinases in H2O2-induced apoptosis were examined. Involvement of ERKs in the induction and activation of AP-1 was also investigated using Northern blot analysis and a reporter assay. RESULTS: Mesangial cells exposed to H2O2 exhibited rapid phosphorylation of JNK, ERKs, and p38 MAP kinase. Quercetin abrogated the activation of all three MAP kinases in response to H2O2. Pretreatment with MAP kinase kinase inhibitor PD098059 or JNK-c-Jun/AP-1 inhibitor curcumin attenuated the H2O2-induced apoptosis. In contrast, the p38 MAP kinase inhibitor SB203580 did not improve the cell survival. Consistently, transfection with dominant-negative mutants of ERK1 and ERK2 or a dominant-negative mutant of JNK inhibited H2O2-induced apoptosis. Transfection with a dominant-negative p38 MAP kinase did not attenuate the apoptotic process. Inhibition of ERKs by PD098059 suppressed induction of c-fos without affecting early induction of c-jun, leading to attenuated activation of AP-1 in response to H2O2. CONCLUSIONS: These results suggested that (1) activation of JNK and ERKs, but not p38 kinase, is required for the H2O2-induced apoptosis; and (2) suppression of the JNK-c-Jun/AP-1 pathway and the ERK-c-Fos/AP-1 pathway is involved in the anti-apoptotic effect of quercetin.     

The effect of interleukin-6 on enhancing the invasiveness of head and neck cancer cells in vitro

Patients with head and neck cancers that produce a high concentration of granulocyte colony-stimulating factor (G-CSF) or patients with esophageal squamous cell carcinomas who have elevated serum interleukin-6 (IL-6) concentrations have been found previously to be at significant risk for tumor invasion to adjacent organs as well as frequent metastases. This suggests that G-CSF and Il-6 enhance the invasiveness and metastatic potential of cancer cells. We studied the in vitro invasiveness of head and neck cancer cell lines with and without recombinant human G-CSF (rhG-CSF) and human IL-6 (hIL-6) in an extracellular matrix membrane system. The degree of invasiveness was affected by incubating cells with hIL-6, but not by pre-incubating the cell-matrix with hIL-6. The maximum concentration of hIL-6 for enhanced invasiveness was approximately 5,000 u/ml. In addition, rhG-CSF enhanced the invasiveness of tumor cells that produced large amounts of G-CSF. The present study also suggests that tumor cells tend to invade and metastasize in an environment rich in hIL-6. Received: 3 November 1997 / Accepted: 1 April 1998     

A new mutation in the POU3F4 gene in a japanese family with x-linked mixed deafness (DFN3)

Objective: The molecular defect in patients with X-linked mixed deafness showing a perilymphatic gusher at stapedectomy (DFN3) has been attributed to mutations in the POU3F4 gene. This study aimed to clarify an allelic variant of this gene. Study Design: This was a genetic study of a single Japanese family with DFN3. Methods: Products of a polymerase chain reaction (PCR) were subjected to single-strand conformation polymorphism (SSCP) analysis. Direct sequencing of PCR products from patients and carriers showing SSCP variants was performed using the fluorescent dideoxy termination method and a sequencer. Results: Sequencing of the PCR product revealed a 6-base deletion (TTCAAA) at nucleotides 601 to 606, resulting in a two-amino-acid deletion in the POU3F4 protein, (phenylalanine and lysine at amino acid residues 201 and 202). The deletion was adjacent to the site of a nonsense mutation previously described. Conclusion: Microdeletions at a previously undescribed location account for some clinically important POU3F4 mutations. Laryngoscope, 108:1544–1547, 1998     

Is upper mediastinal lymphadenectomy necessary in squamous carcinoma of the lower thoracic oesophagus?

AIM: We examined the indication of upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus. METHODS: 49 patients underwent a curative oesophagectomy with upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus. Node status and clinicopathological characteristics of these patients were reviewed retrospectively. RESULTS: 16 (94.1%) of 17 patients with superficial tumours had no positive node in the upper mediastinum. Nine (29.0%) of 31 patients with transmural tumours had positive nodes in the upper mediastinum (P = 0.04). Ten (20.4%) of 49 patients had many positive nodes in the upper mediastinum. Of these 10 patients, 6 patients had 5 or more positive nodes in all. The 5-year survival rate for patients with 5 or more positive nodes was 7.7%, which was significantly poorer than patients with 4 or fewer positive nodes. CONCLUSIONS: Upper mediastinal lymphadenectomy is unnecessary in most of the superficial squamous carcinomas of the lower thoracic oesophagus.     

Gender difference in alcoholic liver injury]

Gender differences of alcoholic liver injury have been described previously, but mechanisms have only partially characterized. For example, it is known that females develop alcoholic liver injury more rapidly and to a greater extent than males. It now appears that estrogen participates in several aspects of this phenomenon. On the other hand, attention has been directed towards the effect of ethanol ingestion on Kupffer cell function, which is stimulated by gut-derived endotoxins via mechanisms dependent on increased gut permeability and the possible relationship between Kupffer cell and alcohol-induced liver injury.