Role of nitric oxide and superoxide anion in leukotoxin-, 9,10-epoxy-12-octadecenoate-induced mitochondrial dysfunction

The present study was carried out to explore the involvement of nitric oxide (NO) and superoxide anion (O2.-) in Leukotoxin (Lx)-induced suppression of mitochondrial respiration. Glutamate- and succinate-dependent oxygen consumption and cytochrome c oxidase activity were assayed. Lx-induced mitochondrial damage was significantly attenuated by the pretreatment of lung with 4 x 10(-4) M NG-monomethyl-L-arginine (L-NMMA) or 500 units/ml superoxide dismutase (SOD) in ex vivo. However, L-NMMA plus SOD pretreatment showed no additive effect on the recovery of mitochondrial functions. The same assay was performed after the exposure of intact mitochondria to NO containing solution (1.25 x 10(-5) M) or 0.1 mM KO2/18-Crown-6 solution, which generated O2.-(6.4 x 10(-5) M). NO, but not O2.-, significantly inhibited the respiration of isolated mitochondria in vitro. Thus, there were great discrepancies in the involvement of NO and O2.- between ex vivo and in vitro system. Together with the previous reports, these facts suggested that the mechanisms by which NO and O2.- probably from vascular constituent cells inhibit mitochondrial respiration function of isolated perfused rat lung may not be simply due to their direct reactions with mitochondrial electron transport chain components, but may rely on the formation of peroxynitrite, and/or peroxynitrite-derived oxidants.

Reduction of nitric oxide with L-/NG-monomethyl arginine in interleukin-2 and anti-CD3 monoclonal antibody combination therapy

We evaluated nitric oxide induction in antitumor therapy consisting of anti-CD3 monoclonal antibody (anti-CD3) and interleukin-2 (IL-2), then determined the effect of nitric oxide reduction with L-N(G)-monomethyl arginine (LNMA) on the therapeutic methods. Female C57BL/6 mice, MCA102 (a non immunogenic, NK-resistant murine fibrosarcoma cell line), and 145-2C11 (hamster anti-murine-CD3 mAb) were utilized in an experimental hepatic metastasis model developed by injecting a tumor cell suspension into the spleen of mice. A marked increase in serum NO2 (-) + NO1 was observed at 19 hours after anti-CD3 (10 μ, IV) and additional IL-2 administrations (40 × 10(1) U, twice, If) induced a further increase. The NO2, + NO3- elevation in spot urine in the combination therapy was not suppressed with LNMA at a dose of 100 μg/h but was significantly lowered at 300 μg/h. The efficacy of the anti-CD3 + IL-2 therapy was not diminished by LNMA administration either at 100 μg/h or at 300 μg/h.

Polyethylene glycol-modified avidin: a novel agent for the selective extraction of biotinylated immune-complex in an aqueous two-phase system

Chicken avidin was chemically modified with 2,4-bis[O-methoxypoly(ethylene glycol)]-6-chloro-s-triazine (activated PEG2) to form PEG-avidin. The PEG-avidin, in which 78% of the amino groups were modified, retained 49% of the active biotin-binding sites. The modified avidin was partitioned preferentially into the PEG-phase in an aqueous two-phase system (PEG/dextran). Using PEG-avidin, the immune-complex formed between biotinylated anti-mouse IgG and its antigen IgG (mouse) molecules, was successfully transferred into the PEG-phase in an aqueous two-phase system. This finding leads to the effective isolation of a specific antigen among various kinds of antigens by partitioning with a two-phase system using PEG-avidin.

Increased Ca2+ influx in the resting state maintains the myogenic tone and activates charybdotoxin-sensitive K+ channels in femoral arteries from young SHR

1. To determine the possible role of voltage-dependent Ca2+ channels (VDCC) and Ca2+-activated K+ (KCa) channels in the regulation of resting tone of arteries from young spontaneously hypertensive rats (SHR), mechanical responses to the agents which interact with these channels were examined in endothelium-denuded strips of femoral arteries from 4 week old SHR and age-matched normotensive Wistar-Kyoto (WKY) rats. Systolic blood pressures at this age were not significantly different between SHR and WKY. 2. The strips from SHR, but not from WKY, maintained a myogenic tone; that is, the resting tone decreased when nifedipine was added. 3. Studies using 1 or 5 min pulse labelling of the strips with 45Ca showed that the basal Ca2+ influx was increased in SHR when compared with WKY, and this increase in SHR was abolished by nifedipine. Similar results were obtained when the cytoplasmic Ca2+ concentration ([Ca2+]i) in the resting state of the strips was measured by fura-PE3. 4. The addition of charybdotoxin (ChTX, a blocker of large conductance KCa channels) to the resting state caused a concentration-dependent contraction, which was much greater in SHR than in WKY. The ChTX-induced contraction in SHR was abolished by nifedipine. 5. In strips preloaded with 86Rb, the basal 86Rb efflux rate constant was significantly greater in SHR than in WKY. The increase in 86Rb efflux in SHR was abolished by nifedipine. 6. The results suggest that the Ca2+ influx via L-type VDCC was increased in the resting state of the femoral artery from 4 week old SHR, and therefore the myogenic tone was maintained and ChTX-sensitive K+ channels were highly activated.

Early appearance of age-associated deterioration in mitochondrial function of diaphragm and heart in rats treated with doxorubicin

Age-associated deterioration of mitochondrial energy transduction seems to be a major contributory factor to age-related decline in organ function. Free radicals are likely to be involved in the age-related decline in mitochondrial function. This study was designed to elucidate whether or not doxorubicin, a radical generating drug that was administered to 7-week-old rats, affects age-associated mitochondrial functional changes in diaphragm, heart, and liver. Mitochondria from each tissue were prepared from rats aged 7, 13, 20, 28, 35, and 55 weeks, and the activities of four complexes in the mitochondrial energy transduction system were measured enzymatically. In diaphragm mitochondria of the control group, the complex I activity in 28-week-old rats declined to 82% of the activity in rats aged 7 weeks, and the complex IV activity in 55-week-old rats declined to 70% of the activity in rats aged 7 weeks. On the contrary, a significant decrease in the activity of complex I in rats aged 20 weeks (84%) and that of complex IV in rats aged 35 weeks (86%) were observed in the doxorubicin-treated group. In heart mitochondria, age-related changes in activities of complexes I and IV did not appear in rats aged up to 55 weeks, whereas significant decreases in the activities of complexes I (78%) and IV (90%) were observed in rats aged 35 weeks in the doxorubicin group. Age-related changes in liver mitochondria were not found in rats aged up to 55 weeks, and no deleterious effects of doxorubicin were observed in liver mitochondrial function. From these results, the early appearance of aging effects on mitochondrial function was observed in rats treated with doxorubicin particularly in postmitotic cells.

Mitochondrial DNA minicircles, lacking replication origins, exist in the cardiac muscle of a young normal subject

This is the first report that mitochondrial (mt) DNA 'minicircles,' lacking replication origins, exist in the heart mtDNA of a young normal subject. A total detection system using 180 kinds of PCR primer pairs was recently devised to detect all possible deletions in mtDNA. To assess the reliability of the system, template mtDNAs were prepared from the heart muscle by three different methods including DNAase digestion. The methods for mtDNA preparation and the nuclear DNA contaminants were demonstrated to have few influences on the analysis. With not less than 95% accuracy, 52 types of deletions including 36 types of minicircles were detected in the subject's mtDNA. These results will give an insight to the mechanism of mtDNA deletion and to the relevance of the deletion with normal aging.

[An operative case of the dumbbell type retromediastinal schwannoma]

Neurogenic tumors of the mediastinum with an intraspinal component connected by a narrowed segment in the intervertebral one are generally described as dumbbell or hour-glass tumors, which need cautious and precise diagnoses and remedies, compared with other neurological tumors. A 62-year-old male was admitted to our hospital for abnormal tumor shadow in the chest X-ray film. We diagnosed this case as dumbbell type neurogenic tumor by MRI and CT. An operation was performed by modified Grillo's method: One-stage operation. With patient in prone position, L-shaped skin incision was made. Through total laminectomy of T-5 and T-6 and resection of the 6th rib, paravertebral portion of the tumor was removed, and thoracotomy in the same position under the same view enabled us to remove the residual tumor. Histopathological diagnosis was schwannoma. After the operation, no neurological complications were detected.

Endothelin-1 potentiates leukotoxin-induced edematous lung injury

We tested the hypothesis that leukotoxin (Lx), a cytochrome P-450-dependent linoleate product of leukocytes, can stimulate the release of endothelin-1 (ET-1) from the lung and further that exogenous ET-1 synergizes with Lx to produce edematous lung injury. In isolated rat lungs perfused with Earle's balanced salt solution, Lx (10 mumol) alone caused lung edema and increased the perfusate and lung tissue ET-1 levels. The combination of ET-1 (5 nM) and Lx (5 mumol), at concentrations that by themselves did not increase wet lung weight, significantly increased wet lung weight, wet-to-dry lung weight ratio, as well as the lung effluent lactate dehydrogenase activity. Pretreatment with BQ-123 (5 x 10(-6) M), an endothelin A receptor antagonist that significantly attenuated the ET-1 (5 nM)-induced increase in pulmonary arterial pressure (Ppa) and pulmonary capillary pressure (Ppc), suppressed the edematous lung injury generated by the combination of ET-1 and Lx, suggesting that the edema-enhancing effect of ET-1 in Lx-treated lungs occurred through endothelin A receptor-dependent elevation of Ppa and Ppc. Elevation of the pulmonary venous pressure in Lx-treated lungs (13.5 cmH2O) mimicked the effect of ET-1 on Ppa and Ppc and produced a degree of lung edema that was comparable to that after combined ET-1 + Lx treatment but without increase in the perfusate lactate dehydrogenase. These data support the idea that ET-1 and Lx promote lung edema in a synergistic fashion.

[A study on the rhodopsin gene in Japanese retinitis pigmentosa--screening of mutation by restriction endonucreases and frequencies of DNA polymorphisms]

We analyzed 11 sites of the rhodopsin gene using polymerase chain reaction (PCR) amplification and restriction endonucleases in 30 unrelated Japanese patients with autosomal dominant retinitis pigmentosa (ADRP). No point mutation was found in any patient. The frequencies of the single nucleotide (nt) substitution at nt 269, nt 5145 and nt 5321 were examined in three groups, 38 unrelated patients with ADRP, 23 patients with autosomal recessive retinitis pigmentosa (ARRP), and 67 normal controls. There was no significant difference in the frequencies of substitution among these three groups. The frequencies of A269G, G5145A, and C5321A were 52%, 36%, and 5%, respectively. These values were different from those of the American population. The polymorphisms, A269G and G5145A, are useful as DNA makers for linkage analysis.

[Ultrasonography of pediatric right lower abdominal pain: correlation with clinical and pathological results]

Right lower abdominal pain is a common problem in the pediatric population. Ultrasonography (US) is a well-accepted imaging modality in the clinical management of this problem. One hundred and six consecutive pediatric patients with right lower abdominal pain were prospectively evaluated. There were 54 boys and 52 girls, with ages ranging from 3 to 15 years (mean: 9.9 years). Final diagnoses were established based on pathological findings or clinical follow-up. US had sensitivity of 90%, specificity of 98%, and accuracy of 94% in the diagnosis of acute appendicitis. Among all true negative cases (n = 55), there was a variety of US findings other than appendiceal abnormality in 21 cases including intestinal and/or mesenteric (n = 19), gallbladder (n = 1), and ovarian (n = 1) abnormalities. All 21 cases were managed medically without complication. We conclude that US of pediatric right lower abdominal pain is a reliable imaging modality not only for the diagnosis of surgical cases but for eliminating the unexpected surgical intervention.

[Transient achromatopsia caused by cardioembolic brain ischemia]

A 51-year-old right-handed man with dilated cardiomyopathy, sleep apnea and atrial fibrillation suddenly suffered from transient color imperception, which completely recovered next morning. During the attack, both color naming and color pointing were severely disturbed, while he could correctly state the colors of named objects. There were no additional neuropsychological disturbances such as aphasia, alexia and prosopagnosia. Brain MRI revealed a new ischemic change, i.e. laminar cortical necrosis, in the right fusiform gyrus as a causative lesion as well as old asymptomatic infarcts in the left middle cerebral arterial territory. Cardioembolism was considered to be responsible for the development of brain ischemia. The transient achromatopsia is a rarely reported disease and this case appears to support 'ischemia' as its etiology.

Leukotoxin, 9,10-epoxy-12-octadecenoate inhibits mitochondrial respiration of isolated perfused rat lung

To investigate how mitochondrial function was affected in leukotoxin (Lx)-,9,10-epoxy-12-octadecenoate-induced lung injury, lung mitochondria were extracted from isolated perfused rat lung with or without Lx-induced edematous injury. In the lung treated with 30 mumol of Lx, the mitochondrial respiration rate in states 3 and 4 significantly decreased (without mitochondrial uncoupling) concomitantly with increased release of lactate dehydrogenase (LDH), a parameter for cellular damage, into the perfusate and decreased ATP content in the lung tissue compared with those of untreated lung. Moreover, 30 mumol of Lx resulted in significant inhibition of cytochrome-c oxidase activity (vs. vehicle control). In contrast, lower doses of Lx (10 mumol) caused lung edema and cellular damage without evidence for mitochondrial dysfunction. We also examined cellular and mitochondrial damage in hydrostatic lung edema. Such edema showed neither suppressed mitochondrial respiration nor elevated LDH activity in perfusate, although lung wet weight increased as much as it did after 30 mumol Lx treatment. Our results suggest that the ex vivo mitochondrial dysfunction is one of the secondary (vs. initial augmented permeability) but specific manifestations of toxicity of Lx, and together with the previous reports, the ex vivo damaging effect of Lx against mitochondria may be ascribed not to its direct action on mitochondria but to Lx-derived cellular mechanism(s).

[Primary seminoma of the prostate and embryonal cell carcinoma of the left testis in one patient: a case report]

A 27-year-old Japanese male presented with gross hematuria and right frank pain, and was diagnosed of having a right ureteral stone by IVP. Though the stone was passed spontaneously, gross hematuria continued, and his urinary stream became week. The prostate was moderately enlarged. The prostate biopsy was initially thought to represent prostate rabdomyosarcoma. He underwent a pelvic extenteration followed by chemotherapy with dacarbazing and ADM. Three years after the pelvic exenteration, coin lesions were found on a chest X-ray film. He was diagnosed as embryonal cell carcinoma of the left testis with pulmonary metastasis and received 3 courses of PVB therapy. At this time, the former diagnosis of prostatic rabdomyosarcoma was changed to prostatic rabdomyosarcoma was changed to prostatic seminoma, because placental-ALP staining was positive. This patient had two distinct germinal cell tumors in the prostate and the left testis. He was alive without any tumor recurrence 20 months after PVB chemotherapy. To the best of our knowledge our report represents the first patient of seminoma of the prostate in the world.

Missense mutation of rhodopsin gene codon 15 found in Japanese autosomal dominant retinitis pigmentosa

Heterozygous missense mutation in codon 15 of the rhodopsin gene was detected in a patient with autosomal dominant retinitis pigmentosa (ADRP), where a transition of adenine to guanine at the second nucleotide in codon 15 (AAT-->AGT), corresponding to a substitution of serine residue for asparagine residue (Asn-15-Ser) was detected. None of the remaining unrelated 42 ADRP, 24 autosomal recessive RP (ARRP) and 34 normal individuals had this alteration. Her funduscopic findings were sectorial in type similar to that of the patients with the same mutation found in an Australian pedigree (Sullivan et al., 1993). This study shows phenotypic similarities in patients with the same mutation of a different ancestry.

[Expression of GP160 mRNA in renal cell carcinoma: an attempt to predict the sensitivity of IFN-alpha therapy]

BACKGROUND

Alpha-interferon (IFN-alpha) has significant antitumor activity against advanced renal cell carcinoma (RC). Although numerous clinical trials reported major responses in approximately 15% of patients subjected to INF-alpha therapy, it has been impossible to predict which patients will respond to IFN-alpha. RC cell lines could be subdivided into those that are inhibited by IFN-alpha and those that are not. The expression of GP160 (Aminopeptidase a/kidney-associated differentiation antigens) correlated with resistance to IFN-alpha. In RC xenografts using a mouse model, though GP160(+) RC cell lines were resistant to IFN-alpha, GP160(-) RC cell lines were markedly sensitive to IFN-alpha.

METHOD

In this study, we assayed 26 RC patients for the expression of GP160 in mRNA level using RT-PCR (reverse transcription polymerase chain reaction).

RESULTS & CONCLUSION

In 23 (88.5%) patients GP160 mRNA expression are remarkable as in normal kidney tissue, but in 2 (7.7%) patients, GP160 mRNA expression was weak. And in 1 (3.8%) patient, GP160 mRNA expression was hardly detectable, and in this patient complete remission was achieved with IFN-alpha therapy for advanced lung and mediastinal metastatic RC.

[Combination chemotherapy with tegafur-uracil (UFT) and cisplatin (CDDP) for advanced gastric cancer. UFTP Study Group]

An early phase II study of tegafur-uracil (UFT) combined with cisplatin (CDDP) was conducted in patients with advanced gastric cancer. UFT was administered orally for 28 consecutive days at a dose of 400 mg/m2 and CDDP was injected intravenously for 3 day at a dose of 30 mg/m2 over 8 hours every 4 weeks. This treatment cycle was repeated every 4 weeks. Sixteen patients were enrolled in this study and 14 patients could be evaluated for clinical response and toxicity. Based on the results of extramural review, 6 of 14 patients achieved a partial response and the response rate was 42.9%. High grade toxicities (WHO grade 3 or 4), specifically anorexia, nausea and vomiting, diarrhea, and leukocytopenia, were seen in 5, 2, 3 and 2 patients, respectively. The overall median survival time was 347 days (11.4 months) for evaluated patients. Although these results are preliminary, this regimen does appear to be effective in terms of tumor response and survival. Larger patient numbers in a Phase II study and further studies to evaluate survival are awaited.

[A case of rheumatoid arthritis with malignant lymphoma taking methotrexate]

We describe one case with rheumatoid arthritis who developed non-Hodgkin's lymphoma during treatment with low dose weekly methotrexate. A 73 year-old man had seropositive RA since 1974. He had been treated with several medications, including nonsteroidal antiinflammatory drugs, gold sodium thiomalate (from January, 1987), and bucillamine (from January, 1988). He presented to this hospital in April 1988, at a time when his rheumatoid arthritis worsened. Methotrexate was administered at a weekly dose of 7.5 mg orally, together with a daily dose of 5 mg of prednisone. He had had no joint-related pain and no side effects until December 1991 (total dose 1290 mg) when severe abdominal pain was started abruptly. The chest X-ray showed an abdominal free air and a diagnosis of acute panperitonitis was made. An emergency operation was carried out. There was a soft-tissue mass in the terminal of ileum which was ruptured with massive ascites. Histologic examination of the mass revealed a diffuse large cell lymphoma. The oncogenic potential of MTX and rheumatoid arthritis is reviewed.

Approaches that mitigate doxorubicin-induced delayed adverse effects on mitochondrial function in rat hearts; liposome-encapsulated doxorubicin or combination therapy with antioxidant

This experiment was designed to evaluate whether or not liposomal encapsulated-doxorubicin and combination therapy of free doxorubicin with coenzyme Q10, an antioxidant, mitigate the delayed adverse effects on cardiac muscle mitochondria. Rats aged 7 weeks were divided into the following four groups; rats were injected with doxorubicin or liposomal encapsulated-doxorubicin, total dose 15 mg/kg. The doxorubicin group consisted of two subgroups depending on diet, i.e., standard diet or 0.2% coenzyme Q10 diet. Mitochondria from cardiac muscles were prepared from rats aged 13 and 35 weeks. No significant decrease in the activity of complex I of the mitochondrial electron transport chain was observed in rats aged 13 weeks among the groups, however, significant decreases in the activity in rats aged 35 weeks were observed in the doxorubicin and liposomal doxorubicin groups compared with the corresponding control rats. In contrast, no significant change in complex I activity was observed in rats fed with coenzyme Q10 diet irrespective of doxorubicin treatment. From these results, not liposomal encapsulation of doxorubicin but combination therapy with antioxidant might be expected to reduce the delayed adverse effects of doxorubicin on heart mitochondria.

Mutations in the Norrie disease gene: a new mutation in a Japanese family

Images

[Study on clinical courses of 7 patients undergone resection of adjacent organs in the treatment of locally extensive renal cell carcinoma]

Significance of surgical extirpation of a massive tumor involving adjacent viscera is still controversial, because this sort of extensive resection is unusual and its results are poor in terms of a short survival time. Here, we summarize the clinical courses of 7 patients who had been diagnosed as invasive renal cell carcinoma (RCC) and undergone extensive resection of the bowel and/or other adjacent visceras. In addition, a percentage of patients who had direct invasion and/or metastasis to adjacent viscera in routine autopsies was looked up in the Annual Report of the Pathological Autopsy Cases in Japan. Pathological diagnosis indicated that direct invasion was confirmed in 4 out of 7 patients. One patient was relieved from septic shock due to pelvicocolic fistula caused by a direct invasion of RCC. New metastases developed in all patients after the radical operation (2 - 30 mos), and 3 of them further underwent resection of the metastastic lesion(s). Although 5 patients ultimately died of cancer or its related diseases (mean survival time: 14.2 +/- 10.7 mos), other 2 (pT4 and pT3) who underwent resection of lung metastasis have survived for 19 and 72 months. Either an early occurrence of metastasis after local resection or a tumor predominantly composing of spindle cells might indicate a poor prognosis. Surgical extirpation should not be precluded when the patient is having severe symptoms related to extensive involvement of the adjacent visceras. We believe that it is appropriate to individualize in case of choosing patients for such extended radical surgery.

[The advantage of a thin flexible ureteroscope with a new real-time processing system]

To observe the upper urinary tract more clearly with a thin flexible endoscope, we developed a novel real-time processing system. This system enhances the parts of the dark cladding around the core by individual strong brightness of each image fiber. The upper urinary tract in eight patients was examined using a thin flexible endoscope with this system at retrograde pyelography or at urological operation. Six patients had hydronephrosis and 2 had filling defects in the renal pelvis or calyx. The endoscope was 0.75 mm in diameter and had 300 pixels of image fiber. The objective portion could be assessed successfully in seven of eight. Significantly finer and colorful image could be obtained with this system compared with the conventional method and the epithelium could be clearly observed. We conclude that this real-time processing system remarkably improves the quality of image obtained with the thin flexible ureteroscope and makes it a more promising modality in the diagnosis and treatment of the upper urinary tract.

[Clinical study on Fournier's gangrene--value of "through and through drainage"]

From 1991 to 1994, we experienced 5 patients with Fournier's gangrene. Their age, associated diseases, etiology, area of the disease, microbiologic findings, treatment and prognosis were reviewed. Patient age ranged from 25 to 72 years, with a mean age of 47 years. An associated disease process could be identified in all patients. Two patients had diabetes mellitus, 1 systemic lupus erythematosus, 1 chronic alcoholism and 1 multiple myeloma. The etiology of the infectious process was presumed to be wound infection in 2 patients and indwelling urethral catheter in 2 patients. All patients were treated with broad-spectrum antibiotics. Extensive débridement with later skin graft was done in 2 patients. Multiple Penrose-drains were placed subcutaneously after limited removal of necrotic tissue in 3 patients. In these 3 patients, redness and swelling reduced quickly, the wound was cured without defects of skin except 1 patient who had multiple myeloma and was in a very serious condition. Although inflammation reduced after the placement of drains, the patient with multiple myeloma died of sepsis and DIC. The majority of patients with Fournier's gangrene are immunocompromised. Although extensive débridement is commonly performed as the surgical treatment, defects of the skin seem to have some disadvantages, such as the need for the skin graft and the chance of secondary wound infection. In the narrow excision of necrotic tissue and drainage of involved areas by multiple Penrose-drains, skin defects are minimum, and the effectiveness of the surgical management seems to be competitive with the wide débridement.(ABSTRACT TRUNCATED AT 250 WORDS)