Biomedical subjects
Publications and source records attributed to M Kuroda.
A 69-year-old man was diagnosed with a right renal carcinoma with a tumor thrombus in the inferior vena cava, and underwent a radical nephrectomy. The entire specimen was examined by step-wise sectioning and found to be a thrombus with extensive hemosiderin deposits and recanalization which contained no malignant cells.
We have isolated mutants of Citrobacter freundii that can grow on melibiose. Inducible alpha-galactosidase activity and melibiose transport activity were detected in the mutant cells but not in the wild-type cells. We detected a DNA region which hybridized with melB (the gene for the melibiose transporter) DNA of Escherichia coli in the chromosomal DNA of wild-type C. freundii. Protons, but not sodium ions, were found to be the coupling cations for melibiose (and methyl-beta-D-thiogalactoside) transport in the mutant cells.
Eight spirostanol saponins, including four new compounds, and two known furostanol saponins were isolated from the fresh bulbs of Lilium candidum. The structures of new compounds were determined to be (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->4)] -beta-D-glucopyranoside¿, (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-O-[6-O-acetyl-beta-D-glucopyranos yl- (1-->4)]-beta-D-glucopyranoside¿, (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside¿ and (25S)-spirost-5-ene-3 beta,27-diol 3-O-¿O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-O - [beta-D-glucopyranosyl-(1-->4)]-beta-D-glucopyranoside¿, respectively, on the basis of spectroscopic analysis, including two-dimensional NMR techniques, and the result of hydrolysis. The inhibitory activity of the isolated saponins on Na+/K+ ATPase was evaluated.
Phytochemical examination of the underground parts of Ruscus aculeatus has led to the isolation of a total of twelve steroidal saponins, including seven new ones. The structures of the new saponins were determined by spectroscopic analysis and chemical evidence. The furostanol saponin, having a diglycoside moiety modified with a (2S,3S)-2-hydroxy-3-methylpentanoic acid group and an acetic acid group, and its corresponding spirostanol saponin exhibited cytostatic activity on leukemia HL-60 cells.
A 61-year-old woman presented with high fever, headache and left facial palsy with diplopia. Histopathological examination of the biopsied specimens taken from nasal mucosa and kidney revealed a granulomatous angiitis with giant cell infiltration. Ga-DTPA-enhanced magnetic resonance imaging (MRI) revealed a thickening of dura mater in the middle cranial fossa and tentorium cerebelli. The observed left facial and occulomotor palsy was considered to be caused by pachymeningitis associated with Wegener's granulomatosis (WG). Cyclophosphamide combined with prednisolone effectively improved the symptoms. However, the patient died of acute interstitial pneumonitis, presumably caused by cyclophosphamide. The pathohistology obtained in the autopsy revealed a fibrous thickening of the dura mater in the left meningen with a segmental scarring of the arteries and a necrotizing arteritis in the kidney.
We report a case of squamous cell lung cancer with nephrotic syndrome. A 69-year-old man was admitted because of proteinuria and microhematuria. A plain chest X-ray film on admission showed a large mass in the left-lower lung field. The patient was given a diagnosis of minimal-change-nephrotic syndrome and squamous cell lung cancer. We first treated the nephrotic syndrome with glucocorticoid therapy, and then treated the lung cancer with chemo-radiotherapy. This reduced the lung cancer, alleviated the proteinuria, and completely resolved the nephrotic syndrome. Nephrotic syndrome is generally associated with malignant lymphoma and other nonepithelial neoplasms. As the underlying disease, epithelial neoplasms are less common, but lung cancer is one of the most widely reported. Histologically, most cases of cancer-associated nephrotic syndrome exhibit membranous nephropathy; Minimal-change nephrotic syndrome is rare. Deposits of immunocomplex on glomerular basement membrane are considered to play a pathogenic role in membranous nephropathy. However, the pathogenesis of minimal-change nephrotic syndrome is different.
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Anti-neutrophil cytoplasmic antibody (ANCA) is a distinct marker for Wegener's granulomatosis. We report two cases of ANCA-negative Wegener's granulomatosis. A 70-year-old woman (case 1) and a 27-year-old woman (case 2), who had sinus symptoms and renal disorders, were admitted to our hospital with alveolar hemorrhage. Wegener's granulomatosis was diagnosed on biopsy of the nasal mucosa. Case 1 responded well to the combination therapy with cyclophosphamide and prednisolone, while case 2 responded well to pulse therapy with methyl-prednisolone. These findings suggest that patients with ANCA-negative Wegener's granulomatosis may respond well to chemotherapy. This might lead to an improved prognosis in even severe cases, even though the prognosis of generalized Wegener's granulomatosis with alveolar hemorrhage is usually poor.
A 7-center cooperative clinical study with a new formulation of epirubicin hydrochloride injectable solution (Epirubicin-RTU) was conducted in patients with superficial bladder carcinoma. Epirubicin-RTU at the dose of 60 mg/30 ml was administered by intravesical instillation once daily for three (3) consecutive days and a 4-day drug-free interval followed; then the above intravesical instillation of Epirubicin-RTU was repeated for three consecutive days. All 20 registered cases were eligible, and 18 cases completed the whole course of the study. In 18 completers, CR was observed in 12 cases and PR was observed in one (1) case, for an efficacy rate of 72.2%. The primary adverse reaction was bladder irritation including pollakiuria 85.0% (17/20), miction pain 85.0% (17/20), and hematuria 80.0% (16/20), which were all reversible and tolerable. In urinalysis, urinary sediment showed leukocytes and erythrocytes, and proteinuria was observed. All were reversible. From the above results, this new formulation of Epirubicin-RTU was considered useful for the treatment of superficial bladder carcinoma.
The clinical significance of preoperative prostate specific antigen (PSA) and PSA density (PSAD) in distinguishing stage T1a and T1b prostate cancer from benign prostatic hyperplasia (BPH) was studied retrospectively in men who had undergone surgery for BPH. A total of 202 clinically BPH patients underwent transurethral resection of prostate (TURP) or retropubic prostatectomy, and histopathological findings were BPH in 179 patients, T1a cancer in 10 patients and T1b cancer in 13 patients. The T1a cancer group was similar to the BPH group in all parameters. The PSA and PSAD values in the T1b cancer group were significantly higher than those in the BPH group (P < 0.001). Prostate volume and amount of tissue resected in the T1b cancer group were significantly smaller than those in the BPH group (p < 0.001). The cut-off values of PSA and PSAD were examined with T1a and T1b cancer as a positive control and histologically proven BPH as a negative control. When 8.0 ng/ml was used as the PSA cut-off value, the sensitivity was 65% and specificity was 70%. When 0.25 ng/ml/ml was used as the PSAD cut-off value, the sensitivity and specificity were 65% and 75%, respectively. PSAD was useful for improving the specificity. Almost all the cases undetected by using both cut-off values were of T1a cancer. The receiver operating characteristics curve demonstrated that at any point, PSAD was a better detector for distinguishing T1a, T1b cancer from BPH, focusing especially in the range of PSA level between 6.0 and 10.0 ng/ml. These findings suggest that PSA and PSAD are useful parameters in distinguishing T1b cancer from BPH before surgery.
A 70-year-old man, who was diagnosed by computed tomographic scan as having bilateral synchronous adrenal myelolipomas 6 years ago during the follow-up of fatty liver, underwent tumor resection at our Department because of growth of bilateral tumors without any subjective symptoms. Histopathological examination revealed mature adipose tissue cells without atypism and areas of hematopoietic tissue, including the myelotic, lymphotic, erythrocytic, and megakaryocytic cells. The diagnosis of myelolipoma was confirmed. The in vivo doubling time of bilateral tumors was 16.1 months and 31.3 months, respectively.
A 68-year-old woman admitted to our hospital complaining of urinary incontinence and dysuria. On examination, the labia were found to be fused extensively, with a pinhole opening at the midline. Under spinal anesthesia, the adhesion was clearly separated with the Hegar's dilator. There remains no recurrence in this patient following therapy. The labial adhesion was considered to be an acquired disease caused by infection, trauma in the genitalia, or sexless life, according to hypoestrogenism.
The melibiose carrier of E. coli is a cation-sugar cotransport system. This membrane protein contains four cysteine residues and the transport function is inhibited by sulfhydryl reagents. In order to investigate the importance of the cysteines, we have constructed a set of four melibiose transporters each of which has one cysteine replaced with serine or valine. The sensitivity of this set of carriers to N-ethylmaleimide was tested and Cys364 was identified as the target of the reagent. In addition, we constructed a melibiose transporter in which all 4 cysteines were replaced with either serine (Cys110, Cys310, and Cys364) or valine (Cys235) and we found that, as expected, the resulting cysteine-less transporter was resistant to the action of N-ethylmaleimide. The cysteine-less melibiose carrier had no significant decrease in ability to accumulate melibiose with cotransported sodium ions or protons. Thus, none of the 4 cysteines are necessary for the function of the melibiose carrier.
We cloned a fragment of the chromosomal DNA of Enterobacter cloacae, which enabled a melibiose-negative Escherichia coli mutant lacking melB to grow on melibiose as the sole source of carbon. Transformed cells harboring the hybrid plasmid carrying the cloned DNA showed melibiose transport activity. The nucleotide sequence of the DNA region was determined. One complete open reading frame (ORF) and a part of another ORF were found in the region, and the amino acid sequences were deduced. The complete ORF was found to encode a melibiose transporter which consisted of 425 amino acid residues. Hydropathy analysis revealed that there are about 12 hydrophobic domains in this transporter. The incomplete ORF which exists in the upstream region of the transporter gene seemed to encode an alpha-galactosidase.
Cells of Enterobacter aerogenes can grow on melibiose as a sole source of carbon. This suggests the presence of melibiose operon in this organism. We found that E. aerogenes cells possess both alpha-galactosidase activity and melibiose transport activity, which were induced by melibiose. Neither Na+ nor Li+ stimulated the melibiose transport. However, transport of methyl-beta-thiogalactoside (TMG) was stimulated by Li+ but not by Na+. These findings suggest that the major coupling cation for the melibiose transporter in E. aerogenes is H+. In fact, we observed H+ entry into cells caused by an influx of melibiose and some of its analogs. We cloned the melB gene which encodes the melibiose transporter, and sequenced it. Deduced amino acid sequence of the transporter revealed that the melibiose transporter consists of 471 amino acid residues and the molecular weight was calculated to be 52214 Da. The sequence showed high homology with the sequences of the melibiose transporters of Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae. Higher homology was found with the melibiose transporter of K. pneumoniae than with that of E. coli and S. typhimurium.
PURPOSE: It has been shown that thermochemotherapy (TC) given prior to radiation reduces the number of clonogens, with a resultant decrease in the tumor control radiation dose. The purpose of this article was to investigate using an animal tumor model how this clonogen reduction affects subsequent fractionated radiotherapy, including repopulation of surviving clonogens, and whether the induction TC can increase the therapeutic gain factor (TGF). METHODS AND MATERIALS: The single-cell suspensions prepared from the fourth-generation isotransplants of a spontaneous fibrosarcoma, FSa-II, were transplanted into the C3Hf/Sed mouse foot. TC was given by heating tumors at 41.5 degrees C for 30 min immediately after an intraperitoneal injection of cyclophosphamide (200 mg/kg) when tumors reached an average diameter of 4 mm. Fractionated radiotherapy (R) with equally graded daily doses was initiated 24 h after TC either in air (A) or under hypoxic conditions (H). The 50% tumor control dose (TCD50) and the radiation dose to induce a score 2.0 reaction (complete epilation with fibrosis) in one-half of irradiated animals, RD50(2.0), were obtained, and the TGF was calculated. Our previous results on the fractionated radiotherapy using the same tumor system served as controls. RESULTS: The TCD50(A, single dose) and TCD50(H, single dose) following TC+R were 52.2 and 57.3 Gy, respectively, which were 14.0 and 20.4 Gy lower than those following radiation alone. The TCD50(A, TC+R) increased only slightly when the number of fractions was increased from one to 10 doses, and all TCD50s were significantly lower than the TCD50(A, R alone). Both TCD50(H, TC+R) and TCD50(H, R alone) increased consistently from a single dose to 20 doses, but all TCD50(H, TC+R) were significantly lower than the TCD50(H, R alone). Regarding the normal tissue reaction, the RD50 values both following TC+R and R alone increased consistently from a single dose to 20 daily doses. However, the RD50(TC+R) and RD50(R alone) for each corresponding number of fractions was not significantly different, resulting in the TGFs significantly > 1.0 for combined TC+R treatments, with the exception of 20 daily doses given in air. CONCLUSION: The induction TC decreased the TCD50 values substantially without altering the RD50 for a late reaction, resulting in an significant increase in the TGF. These results encourage the use of TC as an induction treatment prior to fractionated radiotherapy.
The arsenical resistance (ars) operon of the conjugative R-factor R773 confers resistance to arsenical and antimonial compounds in Escherichia coli, where resistance results from active extrusion of arsenite catalyzed by the products of the arsA and arsB genes. Previous in vivo studies on the energetics of arsenite extrusion showed that expression of both genes produced an ATP-coupled arsenite extrusion system that was independent of the electrochemical proton gradient. In contrast, in cells expressing only the arsB gene, arsenite extrusion was coupled to electrochemical energy and independent of ATP, suggesting that the Ars transport system exhibits a dual mode of energy coupling depending on the subunit composition. In vitro the ArsA-ArsB complex has been shown to catalyze ATP-coupled uptake of 73AsO2(-1) in everted membrane vesicles. However, transport catalyzed by ArsB alone has not previously been observed in vitro. In this study we demonstrate everted membrane vesicles prepared from cells expressing only arsB exhibit uptake of 73AsO2(-1) coupled to electrochemical energy.
A 65-year-old woman was admitted to our hospital with the diagnosis of gallbladder tumor. Right extended hepatic lobectomy plus lymph node dissection of the hepatoduodenal ligament and left hepaticojejunostomy with Roux-en-Y reconstruction was performed in July, 1993. The gallbladder tumor was histologically proven to be squamous cell carcinoma. Seventeen months later, the patient experienced dyspnea and pitting edema of the lower legs and was admitted, in December 1994, with a diagnosis of heart failure. Despite intensive cardiac support, she died 12 days after the second admission. Autopsy revealed multiple cardiac tumors in the left and right ventricles, left atrium, left coronary artery, and left diaphragm. Histologically, these tumors were shown to be squamous cell carcinoma, considered to have metastasized from the primary gallbladder carcinoma. As neither local recurrence of the gallbladder carcinoma nor any lymph node metastasis was found, the cardiac metastasis of the gallbladder carcinoma may have occurred via the hematogenous route. Although rare, this route of cardiac metastasis of gallbladder carcinoma may be an important aspect of distant metastasis, which should be monitored for during follow-up after resection of the primary tumor.