PubMed Health⌕ Search

Biomedical subjects

R A Malt

Publications and source records attributed to R A Malt.

At least 19 recordsLinked to original sources
PubMed1992

Survival after hepatic resection for malignant tumours.

A retrospective analysis of 194 patients who underwent hepatic resection for primary or metastatic malignant disease from January 1962 to December 1988 was undertaken to determine variables that might aid the selection of patients for hepatic resection. Hepatic metastases were the indication for resection in 126 patients. The 5-year survival rate was 17 per cent. For patients with resected metastases from colorectal cancer (n = 104), the survival rate at 5 years was 18 per cent. The 5-year survival rate was 27 per cent when the resection margin was > 5 mm compared with 9 per cent when the margin was < or = 5 mm (P < 0.01). No patient with extrahepatic invasion, lymphatic spread, involvement of the resection margin or gross residual disease survived to 5 years, compared with a 23 per cent 5-year survival rate for patients undergoing curative resection (P < 0.02). The survival rate of patients with poorly differentiated primary tumours was nil at 3 years compared with a 20 per cent 5-year survival rate for patients with well or moderately differentiated tumours (P not significant). The site and Dukes' classification of the primary tumour, the sex and preoperative carcinoembryonic antigen level of the patient, and the number and size of hepatic metastases did not affect the prognosis. The 5-year survival rate for patients with hepatocellular carcinoma (n = 42) was 25 per cent. An improved survival rate was found for patients whose alpha-fetoprotein level was normal (37 per cent at 5 years) compared with those having a raised level (nil at 3 years) (P < 0.01). Involvement of the resection margin, extrahepatic spread and spread to regional lymph nodes were associated with an 8 per cent 5-year survival rate versus 44 per cent for curative resection (P < 0.005). The presence of cirrhosis, the presence of symptoms, and the multiplicity and size of the tumour did not affect the prognosis. The 5-year survival rate of 11 patients with hepatic sarcoma was 25 per cent. No patient with peripheral cholangiocarcinoma survived to 1 year in contrast to patients with hilar cholangiocarcinoma, all four of whom survived for more than 14 months.

Adenoma, Bile Duct↗
PubMed1991

Renal angiomyolipoma with sarcomatous transformation and pulmonary metastases.

We report the case of a 49-year-old woman with a large renal angiomyolipoma that invaded the liver. In some areas, the tumor had the appearance of a typical angiomyolipoma; however, it also had foci where the spindle cells of the lesion showed marked cytologic atypia and mitotic activity, giving it the appearance of a high-grade sarcoma. Immunohistochemical studies demonstrated expression of vimentin, desmin, and muscle-specific actin by the sarcoma cells; these findings were consistent with leiomyosarcoma. A second, small typical angiomyolipoma was also present in the kidney. In addition, the liver exhibited focal nodular hyperplasia. Three weeks after resection of the primary renal tumor, pulmonary metastases were diagnosed by fine-needle aspiration biopsy. This is the first report of a case of angiomyolipoma with sarcomatous transformation and biopsy-proven metastatic disease.

Biopsy, Needle↗
PubMed1991

Elective and emergency hepatic resection. Determinants of operative mortality and morbidity.

To determine the reasons for improved mortality and morbidity rates after major hepatic resection, five variables were analyzed retrospectively in 300 patients operated on over a 27-year period: (1) the indication for surgery, (2) the surgical approach, (3) the urgency with which surgery was performed, (4) the nature of the surgical procedure, and (5) the experience of the surgeon. The operative mortality rate decreased from 19% between 1962 and 1979 to 9.7% between 1980 and 1988 (p less than 0.05). The operative mortality rates for patients undergoing resection for benign hepatic neoplasms was 3.4%; for metastatic tumors, 6.3%; for primary hepatic malignancies, 19%; and for trauma, 33%. Fifty-seven percent of operations before 1980 were performed through a thoracoabdominal exposure as compared with 19% after 1980. Overall a thoracoabdominal exposure of the liver was associated with a 20% mortality rate as compared with 8.6% for operations with abdominal exposure of the liver (p less than 0.02). Elective operations accounted for 65% of hepatic resections before 1980, as compared with 90% after 1980, and were associated with an 8.8% mortality rate as compared with 30.7% for urgent and emergency operations (p less than 0.001). Segmental and wedge resections were associated with a 5.3% mortality rate as compared with 14.7% for major hepatic resections (p less than 0.05), but this difference did not affect overall operative mortality rates because there was no change in the proportion of major hepatic resections after 1980. Surgical experience was not a determinant of operative mortality or morbidity rates in elective operations. Although there was no reduction in the complication rate after 1980, there was a reduction in postoperative stay from 26 days before 1980 to 16 days after 1980 (p less than 0.001). A reduction in the incidence of postoperative sepsis and a change in its management was associated with improved operative mortality rates.

Chi-Square Distribution↗
PubMed1990

Expression of two "immediate early" genes, Egr-1 and c-fos, in response to renal ischemia and during compensatory renal hypertrophy in mice.

To identify specific genetic regulatory mechanisms associated with renal ischemia, we measured the accumulation of Egr-1 and c-fos mRNAs in the mouse kidney after occlusion of the renal artery and reperfusion. At 1 h after right nephrectomy and arterial occlusion of the contralateral kidney for 10 or 30 min, Egr-1 mRNA levels were three to five times greater in these kidneys as compared with those in control animals that had sustained unilateral nephrectomy alone and were much greater than levels in the normal organ. Whether ischemia was imposed for 10 or for 30 min, renal Egr-1 mRNA contents were equivalent and remained elevated after 24 h of reperfusion subsequent to 30 min of ischemia. Although c-fos mRNA also accumulated in response to ischemia and reperfusion, the pattern differed from that of Egr-1 in that c-fos mRNA content varied with the duration of ischemia and was undetectable 24 h after injury. Contralateral nephrectomy was not necessary to see the marked accumulation of Egr-1 and c-fos mRNAs with unilateral ischemia. Reflow was necessary, however, since only minimal sequence accumulation occurred by the end of the ischemic period. After left uninephrectomy alone, Egr-1 mRNA levels in the remaining kidney were maximal 30 min after surgery, but were not detectable thereafter; c-fos mRNA levels did not change after unilateral nephrectomy. Differential expression of early growth-related genes implicated in transcriptional activation may influence tissue recovery after renal ischemia.

Animals↗
PubMed1979

Obstructing phytobezoar of an intrahepatic bile duct.

Drainage of a choledochal cyst with a cystogastrostomy allowed food to reflux into the liver, where it obstructed a major right hepatic duct and produced recurrent cholangitis. Partial hepatectomy was necessary for relief. Drainage of choledochal cysts with a long Roux-en-Y loop seems advisable.

Adult↗
PubMed1979

Noncoordinate regulation of cytoplasmic RNA in compensatory renal hypertrophy.

To examine the regulatory role of mRNA in compensatory renal hypertrophy, the accumulation and decay of [3H]orotic acid in poly(A)-containing mRNA in mouse kidney was analyzed after unilateral nephrectomy during the period of maximal rRNA accretion. The distribution of radioactivity between newly synthesized poly(A)-containing and poly(A)-lacing polysomal RNA was altered, but no differences in mRNA half-life were observed in growth compared with effects of sham nephrectomy. Radioactivity in polysomal polyadenylated RNA was diminished by approximately 25% during growth where mice were labeled after nephrectomy, but if mice were labeled 18 h before operation, no difference was noted. Thus, accumulation of newly synthesized poly(A)-containing mRNA relative to RNAs that lack poly(A) is changed early in the course of renal hypertrophy. This noncoordinate regulation may represent a control mechanism effective early in induced cell growth involving mRNAs that lack poly(A).

Animals↗
PubMed1979

Tests and management affecting survival after portacaval and spenorenal shunts.

New data were derived from records of 115 patients undergoing portacaval or spenorenal shunts from 1966 to 1973. The last serum bilirubin level determined before a shunt was the best predictor of operative mortality. The strongest predictor of long term survival was the first serum albumin level measured after admission. Operative mortality was strongly correlated with intraoperative clotting disorders; however, the prothrombin time and the partial thromboplastin time predicated long term survival. Clinical assessment added unique information to conclusion derived from laboratory tests. Results of operation were independent of the skill and experience of the surgeon, except that the best risk patients perhaps may have done better when operated upon by the most experienced surgeons. Once a patient has stabilized after a bleeding episode, he might as well be operated upon at the same admission rather than be discharged to be operated upon at a later arbitrary time.

Ascites↗
PubMed1979

Enhanced colonic carcinogenesis with azoxymethane in rats after pancreaticobiliary diversion to mid small bowel.

Since biliary excretion of metabolites might determine the pattern of intestinal neoplasms induced by azoxymethane, the number and distribution of tumors were studied in rats after pancreaticobiliary diversion to the mid small bowel. Pancreaticobiliary diversion was performed either immediately before the first of 16 weekly injections of azoxymethane or 10 days after the last. Seven months after pancreaticobiliary diversion, persistent ileal hyperplasia was manifested by higher levels of mucosal RNA and DNA compared with controls (34--102%: P less than 0.001), while there was little residual adaptation in the colon. Qualitative and quantitative analysis of fecal bile acids 6--26 wk after pancreaticobiliary diversion showed few differences. Pancreaticobiliary diversion doubled the incidence of colonic tumors, whether operation preceded (P less than 0.005) or followed (P less than 0.02) the course of azoxymethane. Suture-line tumors were common in the small bowel, particularly in the transposed duodenal stump. Despite intense ileal hyperplasia as a consequence of pancreaticobiliary diversion, the ileum remained resistant to chemical carcinogenesis. The potentiation of colonic neoplasms by pancreaticobiliary diversion probably depends on the stimulation of colonic mucosal proliferation.

Adenocarcinoma↗
PubMed1979

Ileal resection potentiates 1,2-dimethylhydrazine-induced colonic carcinogenesis.

The effect of colonic hyperplasia produced by resection of the distal third of the small bowel (DSBR) on the development of chemical carcinogenesis of the colon by dimethylhydrazine (DMH) was tested in rats. For the most part the amounts of RNA and DNA in the small bowel were the same with the combined treatments as with either one alone; quantities of nucleic acids tended to increase only in transverse and distal colon. After 37 weeks the number of neoplasms per rat was increased six-fold by combining DSBR with DMH. Neoplasms were spread throughout the colon after combined treatment as opposed to the ascending colong after DMH alone. Postresectional hyperplasia appears to increase the incidence and distribution of colon tumors.

Animals↗