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Biomedical subjects

M Ohto

Publications and source records attributed to M Ohto.

At least 109 records · Page 6Linked to original sources

Development of systemic lupus erythematosus after total resection of a thymoma and the adjacent thymic gland.

We describe a woman with systemic lupus erythematosus presenting with nephropathy after the complete resection of a thymoma and the adjacent thymic gland. The woman showed no symptoms of autoimmune disorders or nephropathy at operation. One year later, however, she noticed arthralgia, and laboratory examination showed mild proteinuria, leukopenia, a high level of serum antinuclear antibody (1:1280), anti-dsDNA antibody, and a low level of complement. Renal biopsy showed focal necrotizing glomerular lesions, suggestive of lupus involvement. The pathogenesis of lupus erythematosus in our case is briefly discussed in relation to preceding thymoma and its resection.

Antibodies, Antinuclear↗

[Treatment of acute cholecystitis by direct-puncture bile aspiration with ultrasound-image control].

We carried out ultrasound guided direct-puncture bile aspiration (DPBA) in 58 patients with acute cholecystitis. Symptoms and laboratory findings of acute cholecystitis were rapidly improved after DPBA. NO serious complications were seen during and after the DPBA procedure. It was concluded that DPBA is practical and safe treatment of acute cholecystitis. Furthermore long follow up study revealed that this therapeutic method would be useful and reliable for elder patients and patients with systemic complication.

Acute Disease↗

[Intrarenal arterial Doppler sonography in patients with various renal disease: correlation of resistive index with biopsy findings].

Duplex Doppler sonography (ultrasonic equipment: Toshiba SSA-270A) were performed in the patients with various renal disease (male 44, female 32) admitted to our hospital between June 1990 and August 1991. Interlobar arterial blood flow velocity was measured at the side of renal pyramid through a longitudinal scan. Both the maximum blood flow velocity (Vmax) and the minimum blood flow velocity (Vmin) were measured quantitatively and resistive index (RI: defined as (Vmax-Vmin)/Vmax) were calculated. Vmax and Vmin correlated well with the creatinine clearance (Ccr) (r = 0.56, r = 0.66 respectively), whereas RI, by which we can detect Doppler waveform changes, correlated weak with Ccr (r = 0.39). We found twenty-nine patients (40%) with an elevated RI (greater than or equal to 0.70). They had severe renal dysfunction and active pathologic findings in the tubulo-interstitial or vascular compartment of the kidney. Doppler examination of renal blood flow velocity was valuable not only to estimate renal function but also to assess pathophysiology of renal disease.

Adult↗

Resolution of acute hepatitis C after therapy with natural beta interferon.

To test whether interferon can prevent acute non-A, non-B hepatitis from becoming chronic, a prospective controlled trial was conducted in 25 patients; 11 were treated for an average of 30 days with a mean of 52 megaunits of interferon and 14 acted as controls. 4 patients in the treatment group who continued to have raised serum aminotransferase concentrations after a year's follow-up were given a second course of interferon. Follow-up at 3 years has revealed that all but 1 of those treated showed normal serum aminotransferase, whereas only 3 controls showed such change (p less than 0.02). Serum hepatitis C virus RNA became undetectable in 10 of 11 treated and in only 1 of 12 control patients, which suggests that interferon prevents the progression of acute non-A, non-B hepatitis to chronicity by eradicating HCV.

Acute Disease↗

Mutations in the precore region of hepatitis B virus DNA in patients with fulminant and severe hepatitis.

BACKGROUND: The presence of the hepatitis B e antigen (HBeAg) in serum is known to be a marker of a high degree of viral infectivity. However, fulminant hepatitis may occur in persons who are negative for HBeAg. A single point mutation has been reported to produce a stop codon in the precore region of hepatitis B virus DNA and prevent the formation of the precore protein required to make HBeAg. To determine whether a precore-mutant virus is causally related to severe liver injury, we analyzed the entire precore region in viral strains isolated from patients with fatal cases and uncomplicated cases of hepatitis B. METHODS: Serum was obtained from 9 patients with fatal hepatitis B (5 with fulminant and 4 with severe exacerbations of chronic hepatitis) and 10 patients with acute, self-limited hepatitis B. Serum samples from a sex partner implicated as the source of the virus in one case of fulminant hepatitis were also studied. The 87 nucleotides in the precore region of the hepatitis B virus were amplified by the polymerase chain reaction and then directly sequenced. RESULTS: Of the nine patients with fatal hepatitis, seven had retrievable hepatitis B DNA: In all seven there was a point mutation from G to A at nucleotide 1896 of the precore region, converting tryptophan (TGG) to a stop codon (TAG). In contrast, this mutation was not found in the 10 patients with acute, self-limited hepatitis B. The hepatitis B DNA from the implicated source contained a sequence with the stop-codon mutation that was identical to the sequence in her partner, who had fulminant hepatitis. CONCLUSIONS: The presence of a mutant viral strain is associated with and may be involved in the pathogenesis of fulminant hepatitis B and severe exacerbations of chronic hepatitis B.

Acute Disease↗

Ras gene mutations in intraductal papillary neoplasms of the pancreas. Analysis in five cases.

Five intraductal papillary neoplasms of the pancreas were analyzed for the presence of the Ras gene mutations. Three (60%) of the five neoplasms showed point mutations at K-ras codon 12. This incidence of the mutations was rather low compared with that found with ordinary pancreatic adenocarcinoma. The presence of the mutations did not correlate with the severity of cellular atypia, but was apparently related to the size of the tumor. The two neoplasms that had no mutations were smaller than the others that had mutations. The analysis suggested that Ras gene mutation is not the first genetic alteration of tumor progression, but that it occurs during the development of neoplasms of the pancreas.

Adenocarcinoma, Papillary↗

Randomized, double-blind, placebo-controlled trial of eight-week course of recombinant alpha-interferon for chronic non-A, non-B hepatitis.

Forty-nine Japanese patients were enrolled in a randomized, placebo-controlled, double-blind trial of alpha-interferon for chronic non-A, non-B hepatitis: 24 patients received 3 million units of recombinant human alpha alpha-interferon (alpha-2a) thrice weekly for eight weeks, and 25 patients received placebo in a similar schedule. The mean serum alanine aminotransferase (ALT) dropped from 155 +/- 91 (SD) to 69 +/- 72 during interferon treatment, but remained unchanged (158 +/- 140 to 147 +/- 130) during placebo treatment (P less than 0.001). Serum ALT level fell to the normal range in 29% of interferon-treated patients, but in only 4% of placebo-treated patients. Pre- and posttreatment liver biopsies were obtained in all but one case. Average histological activity indices (HAI) were markedly improved in the interferon-treated group (9.5 +/- 3.7 to 7.0 +/- 4.3), but were unchanged in the placebo group (8.5 +/- 4.3 to 8.5 +/- 4.9). In addition, we compared the efficacy of interferon treatment between anti-hepatitis C virus (HCV) antibody positive and negative groups. Biochemical and histological improvements were similar and statistically significant in patients with and without antibody to hepatitis C virus. These data indicate that a eight-week course of alpha-interferon induces biochemical and histological improvement in more than half the patients with chronic non-A, non-B hepatitis.

Alanine Transaminase↗

Detection and partial sequencing of hepatitis C virus RNA in the liver.

To detect hepatitis C virus RNA, total RNA was extracted from liver tissue, reverse transcribed to complementary DNA, and amplified by polymerase chain reaction. The reaction products were analyzed by ethidium bromide staining in acrylamide gel and hybridization with a radiolabeled probe. Hepatitis C virus RNA was thereby detected in 17 of 27 (63%) liver tissue specimens obtained from patients with non-A, non-B chronic liver diseases. Of these 27 patients, viral RNA was detected in 12 of 17 (71%) liver tissues from anti-hepatitis C virus-positive patients and in 5 of 10 (50%) liver tissues from anti-hepatitis C virus-negative patients. Direct sequencing of amplified complementary DNA (35 nucleotides) of the 17 RNA-positive samples showed only 66% to 77% homology to the reported hepatitis C virus complementary DNA sequence. These results indicate that the majority of anti-hepatitis C virus-positive patients are currently infected with hepatitis C virus, and some of the anti-hepatitis C virus-negative patients with non-A, non-B hepatitis are harboring hepatitis C virus in the liver. Detection of hepatitis C virus RNA appears to provide a useful indicator in the study of hepatitis C virus infection.

Base Sequence↗

Detection and direct sequencing of hepatitis B virus genome by DNA amplification method.

Hepatitis B virus (HBV) DNA was detected with amplification by the polymerase chain reaction method. Cloned HBV DNA equivalent to one virus genome (3 x 10(-6) pg) was detectable by ethidium bromide staining after 50 cycles of polymerase chain reaction. By applying this method, presence of HBV DNA was studied in 23 hepatitis B surface antigen (HBsAg)-positive and 11 HBsAg-negative sera from patients with chronic liver disease. Hepatitis B virus DNA was positive in 8 of 8 hepatitis B e antigen (HBeAg)-positive, in 2 of 2 HBeAg- and anti-HBe-negative, and in 12 of 13 anti-HBe-positive sera. Hepatitis B virus DNA was undetectable in all HBsAg-negative sera even with amplification. To confirm specificity, the amplified product was directly sequenced. Sequences around 122nd and 160th codon of HBs gene, which determines subtypes d/y and w/r, respectively, were analyzed. The results were compatible with recent reports regarding the relation between HBV subtypes and HBV DNA sequence at those codons. Hepatitis B virus DNA could be detected at the level of one virion by gene amplification method, and its sequence could be determined by direct sequencing in a few days.

Base Sequence↗

Clinical application of ras gene mutation for diagnosis of pancreatic adenocarcinoma.

Most pancreatic adenocarcinomas are known to have ras gene (oncogene) mutations. The site of the mutations is localized in codon 12 of K-ras gene. Such high incidence and localization of the ras gene mutations have not been observed in any other human malignancies. Polymerase chain reaction and direct sequencing method enabled us to analyze DNA sequence around codon 12 of K-ras gene in small quantities of specimens obtained from needle biopsies and aspirate samples for pathological diagnosis. All the materials obtained from 12 patients with pancreatic adenocarcinoma showed the mutations, whereas those obtained from 6 patients with chronic pancreatitis showed no mutations. In several cases using the mutations of K-ras gene as a marker, this analysis supplemented conventional pathology and cytology in making the diagnosis of pancreatic adenocarcinoma. The analysis of ras-gene mutations was useful for the clinical diagnosis of pancreatic adenocarcinoma.

Adenocarcinoma↗

Pneumothorax in a patient with Wegener's granulomatosis during treatment with immunosuppressive agents.

We present the case of a 16-year-old woman with Wegener's granulomatosis, who developed a pneumothorax while receiving treatment with cyclophosphamide and glucocorticoids. The lung was re-expanded by tube drainage, and the patient recovered completely while the immunosuppressive treatment was continued in combination with sulphamethoxazole-trimethoprim. A possible role for this antimicrobial drug in the treatment of Wegener's granulomatosis is briefly discussed.

Adolescent↗

MR imaging of small hepatocellular carcinoma: effect of intratumoral copper content on signal intensity.

Small (less than 5 cm) hepatocellular carcinomas (HCCs) in 45 of 112 patients (40.2%) had a high-signal-intensity pattern (relative to that of liver) on T1-weighted magnetic resonance (MR) images. To identify the cause of this pattern, specimens of histologically defined HCC with high- (n = 21), iso- (n = 6), and low- (n = 22) intensity patterns were histologically evaluated for paramagnetic ionic forms of metals. The incidence of steatosis, clear cell formation, and copper accumulation was statistically (P less than .01) higher in tumors with the high-intensity pattern than in those with other patterns. Of 17 HCCs that stained positive for copper, 16 (94%) had a high-intensity pattern; the pattern of one tumor (6%) was isointense. All 21 tumors with the high-intensity pattern had at least one of the findings of steatosis, clear cell formation, or copper accumulation. These features were evident in only four of 28 tumors (14%) with an iso- or low-intensity pattern. Thus, copper accumulation might be a cause of the high-intensity pattern on T1-weighted images of small HCCs.

Adult↗

Histological and morphometrical indicators for a biopsy diagnosis of well-differentiated hepatocellular carcinoma.

Among 597 patients with nodular hepatic lesions who underwent ultrasonically guided needle biopsy, 305 were histologically confirmed as having hepatocellular carcinoma, and 37 patients had borderline lesions. Histological reexamination was correlated with morphometrical analysis on selected cases of well-differentiated, microtrabecular hepatocellular carcinomas (n = 29), borderline lesion (n = 10), typical (mid-sized and macrotrabecular) hepatocellular carcinomas (n = 15) and cirrhotic liver tissue obtained from extranodular hepatic parenchyma of hepatocellular carcinoma patients (n = 47). Morphometrical analyses revealed that the mean cell size and nucleocytoplasmic ratio were most useful for distinguishing well-differentiated, microtrabecular hepatocellular carcinoma from cirrhosis. These two parameters were well correlated with nuclear density. The grade of nuclear density, therefore, seemed to be a convenient semiquantitative indicator for diagnosing well-differentiated hepatocellular carcinoma. A comparison between intranodular and extranodular hepatic tissues was particularly important for its assessment. It is concluded from the results that hepatic nodules presenting a nuclear density larger than two times that of controls could be classified into the overt hepatocellular carcinoma group. From the statistical aspect, the possibility of microtrabecular hepatocellular carcinoma should be considered when a nodule has a nuclear density exceeding 1.3 times that of the extranodular tissue.

Biopsy↗

[Theophylline pharmacokinetics in patients with liver diseases with reference to estimated hepatic blood flow].

Pharmacokinetics of theophylline were determined in patients with liver cirrhosis and idiopathic portal hypertension with reference to estimated hepatic blood flow assessed by indocyanine green (ICG). Decreased plasma clearance of theophylline was noted in patients with liver cirrhosis and the clearance was significantly lower in Child C group than in Child A, B groups (17.5 +/- 3.4 ml/Kg/hr vs 27.6 +/- 8.7, p less than 0.05). Theophylline has been classified as a drug with a low hepatic extraction ratio and it has been believed that changes in hepatic blood flow have little effect on its clearance. The results of present study indicate that theophylline clearance is basically not related to ICG clearance but to theophylline extraction ratio, supporting the common belief. However, it is noteworthy that the clearance was related to decreased hepatic blood flow rather than extraction ratio in a cirrhotic patient with huge extrahepatic shunt, suggesting that hepatic clearance of this drug could be affected by hepatic blood flow under some circumstances.

Adult↗