Search PubMed⌕ Search

Biomedical subjects

M M Maher

Publications and source records attributed to M M Maher.

At least 37 records · Page 2Linked to original sources
PubMed1995

Luminal dopamine modulates canine ileal water and electrolyte transport.

Previous studies have suggested that dopamine stimulates active ileal ion absorption via alpha 2-adrenergic or dopaminergic receptor activation. Identification of a dopamine 1a receptor on rat enterocytes located in intestinal crypts prompted this investigation of the effect of luminally administered dopamine on water and ion transport in the canine ileum. Absorption studies (n = 27) were performed in dogs with 25-cm ileal Thiry-Vella fistulas. Perfusion with [14C] PEG was used to calculate absorption of water and electrolytes from the Thiry-Vella fistula. Experiments consisted of three 1-hr periods: basal, luminal drug infusion at 10(-4) M, and recovery. Agonists used included dopamine (DOP: alpha-adrenergic, D1 and D2 receptor) and SKF 38393 (D1 receptor). Antagonists used included terazosin (TZ: alpha 1) and yohimbine (YOH: alpha 2). DOP caused significant increases in water and electrolyte absorption. TZ and YOH prevented the dopamine-induced proabsorptive response. Luminal DOP may serve as a proabsorptive modulator of ileal transport, acting via alpha 1, alpha 2, and dopaminergic receptors. The development of more potent proabsorptive dopamine analogs, which maintain the ability to broadly activate mucosal receptors, may be useful in such clinical situations as diabetic diarrhea, short gut syndrome, or following small bowel transplantation.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1995

A prospective randomized trial of pancreaticogastrostomy versus pancreaticojejunostomy after pancreaticoduodenectomy.

OBJECTIVE: The authors hypothesized that pancreaticogastrostomy is safer than pancreaticojejunostomy after pancreaticoduodenectomy and less likely to be associated with a postoperative pancreatic fistula. SUMMARY BACKGROUND DATA: Pancreatic fistula is a leading cause of morbidity and mortality after pancreaticoduodenectomy, occurring in 10% to 20% of patients. Nonrandomized reports have suggested that pancreaticogastrostomy is less likely than pancreaticojejunostomy to be associated with postoperative complications. METHODS: Between May 1993 and January 1995, the findings for 145 patients were analyzed in this prospective trial at The Johns Hopkins Hospital. After giving their appropriate preoperative informed consent, patients were randomly assigned to pancreaticogastrostomy or pancreaticojejunostomy after completion of the pancreaticoduodenal resection. All pancreatic anastomoses were performed in two layers without pancreatic duct stents and with closed suction drainage. Pancreatic fistula was defined as drainage of greater than 50 mL of amylase-rich fluid on or after postoperative day 10. RESULTS: The pancreaticogastrostomy (n = 73) and pancreaticojejunostomy (n = 72) groups were comparable with regard to multiple parameters, including demographics, medical history, preoperative laboratory values, and intraoperative factors, such as operative time, blood transfusions, pancreatic texture, length of pancreatic remnant mobilized, and pancreatic duct diameter. The overall incidence of pancreatic fistula after pancreaticoduodenectomy was 11.7% (17/145). The incidence of pancreatic fistula was similar for the pancreaticogastrostomy (12.3%) and pancreaticojejunostomy (11.1%) groups. Pancreatic fistula was associated with a significant prolongation of postoperative hospital stay (36 +/- 5 vs. 15 +/- 1 days) (p < 0.001). Factors significantly increasing the risk of pancreatic fistula by univariate logistic regression analysis included ampullary or duodenal disease, soft pancreatic texture, longer operative time, greater intraoperative red blood cell transfusions, and lower surgical volume (p < 0.05). A multivariate logistic regression analysis revealed the factors most highly associated with pancreatic fistula to be lower surgical volume and ampullary or duodenal disease in the resected specimen. CONCLUSIONS: Pancreatic fistula is a common complication after pancreaticoduodenectomy, with an incidence most strongly associated with surgical volume and underlying disease. These data do not support the hypothesis that pancreaticogastrostomy is safer than pancreaticojejunostomy or is associated with a lower incidence of pancreatic fistula.

Anastomosis, Surgical↗
PubMed1995

Pancreaticogastrostomy and the Whipple procedure: radiographic appearance and complications.

PURPOSE: To evaluate the radiographic appearance of a pancreaticogastrostomy (PG) and its complications. MATERIALS AND METHODS: Seventy-two patients underwent pancreaticoduodenectomy and PG or pancreaticojejunostomy. Those who underwent PG and were evaluated postoperatively with T-tube cholangiography and upper gastrointestinal (UGI) series constitute the study group (n = 22; 10 men, 12 women; age range, 33-88 years). RESULTS: Twenty-one of the patients had a gastric filling defect radiographically detected. Four patients had clinically apparent delayed gastric emptying and one patient had a clinically apparent pancreatic fistula not detected radiographically. Two patients outside the study group had complications: One had a pancreatic fistula seen only with sinography, and one had a PG leak seen only with repeat UGI series and computed tomography (CT). CONCLUSION: PG caused a gastric filling defect in most patients. Suspected pancreatic fistulas are best confirmed with sinography, and suspected PG leaks may require repeat evaluation and CT. Clinical findings of delayed gastric emptying do not correlate with findings of UGI.

Adult↗
PubMed1993

Randomized trial of intraoperative radiotherapy in carcinoma of the stomach.

A prospectively randomized controlled clinical trial was performed comparing surgical resection and intraoperative radiotherapy (IORT) with conventional therapy in adenocarcinoma of the stomach. Patients in the experimental group underwent gastrectomy, and IORT was administered to their gastric bed (20 Gy using 11 to 15 MeV electrons). Patients in the control group underwent gastrectomy alone for early-stage lesions confined to the stomach (stages I to II) or resection and postoperative external beam radiotherapy to the upper abdomen (50 Gy using 6 to 10 mV photons) for advanced-stage lesions extending beyond the gastric wall (stages III to IV). One hundred patients were screened for the study, of whom 60 were randomized and underwent exploratory surgery. Nineteen patients were excluded intraoperatively because of unresectability or metastatic disease, leaving 41 patients in the study. Seven patients (17%) died of complications. The median survival for patients with tumors of all stages was 25 months for the IORT group and 21 months for the control group (p = 0.99). Locoregional disease failures occurred in 7 of 16 (44%) IORT patients and in 23 of 25 (92%) control patients (p < 0.001). Complication rates were similar between IORT and control patients. Although IORT failed to afford a significant advantage over conventional therapy in overall survival, IORT did significantly improve control of locoregional disease.

Actuarial Analysis↗
PubMed1989

Are complications in intraoperative radiation therapy more frequent than in conventional treatment?

To evaluate whether intraoperative radiation therapy (IORT) results in higher complication rates than conventional radiotherapy, 119 patients were studied who entered four prospectively randomized clinical trials that compared IORT with conventional therapy. Malignant neoplasms included 33 gastric carcinomas, 35 retroperitoneal sarcomas, 22 resectable pancreatic cancers, and 29 unresectable pancreatic cancers. One hundred thirty-six complications developed among 66 patients who received conventional therapy, and 108 complications developed among 53 patients who received IORT. There was no statistical significance between treatment groups with respect to the overall incidence of complications. Analysis of types of complications by tumor type using Fisher's exact test revealed only one significant complication: an increased rate of sepsis among the patients with retroperitoneal sarcoma who received conventional therapy compared with their IORT cohorts. The overall complication rate associated with IORT was equivalent to conventional radiotherapy in the treatment of these malignant neoplasms and supported the use of IORT where clinically indicated.

Abdominal Neoplasms↗
PubMed1987

Worth the pain.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Trial of therapy with monoclonal antibody 17-1A in pancreatic carcinoma: preliminary results.

Monoclonal antibody 17-1A was administered to 25 patients with advanced unresectable carcinoma of the pancreas. Ten patients received 17-1A alone in 400 mg doses delivered intravenously, while 15 patients received 400 mg 17-1A absorbed on to autologous peripheral blood mononuclear cells collected by leukapheresis (usual yield greater than 10(9) cells). No toxicity was observed. Twenty-three patients developed circulating anti-murine immunoglobulin within three weeks of treatment, and 11 patients developed circulating anti-idiotypic immunoglobulin. Four out of 19 clinically evaluable patients (21%) showed objective regressions of tumor. Response did not correlate with the presence or absence of anti-idiotypic antibody and did not correlate with the method of treatment with 17-1A alone or 17-1A and mononuclear cells, at the time of current analysis.

Antibodies, Monoclonal↗
PubMed1984

A prospective, randomized study of adjuvant parenteral nutrition in the treatment of sarcomas: results of metabolic and survival studies.

A prospective, randomized study was performed to evaluate the use of total parenteral nutrition (TPN) in a group of young patients receiving aggressive chemotherapy for metastatic or locally recurrent sarcomas. Fourteen patients were randomly selected to receive TPN and 18 to receive conventional oral nutritional support (CN). During the study period (from first dose of chemotherapy to recovery from myelosuppression), the TPN patients received between 1020 and 2100 calories/m2/day (median 1650) and between 5.3 and 12.4 gmN/m2/day (median 8.9), while the CN patients received between 380 and 880 calories/m2/day (median 685) and between 0.0 and 3.7 gmN/m2/day (median 1.5). The mean daily nitrogen balance during the study period for the TPN group (-3.0 to + 1.3 gmN/m2/day, median -0.7) was significantly higher (p = 0.005) than that of the CN group (-6.2 to -0.7 gmN/m2/day, median -2.6). Serum protein levels (albumin, total protein, and transferrin) did not differ between the two treatment groups. The proportion of patients responding to therapy and the long-term survival rates were similar in the treatment groups. Thus despite established improvement in nitrogen balance, no survival or therapeutic advantage was demonstrated for the adjuvant parenteral nutrition group. Further studies of the role of parenteral nutrition as an adjuvant to cancer chemotherapy are needed to determine which populations of patients will benefit from its use.

Adolescent↗
PubMed1983

The effect of total parenteral nutrition on chemotherapy-induced myelosuppression. A randomized study.

We studied the effect of total parenteral nutrition on recovery from myelosuppression in patients receiving intensive chemotherapy. Twenty-seven patients (ages 11 to 33 years) with locally recurrent or metastatic Ewing's sarcoma, rhabdomyosarcoma, or osteosarcoma were randomly selected to receive either conventional oral nutrition or total parenteral nutrition concurrently with intensive chemotherapy. The control group (15 patients) received significantly fewer calories (range 380 to 880/m2 per day, median 685 versus range 1,020 to 2,100 median 1,650) and less nitrogen (0-3.7 g/m2 per day, median 1.5 versus range 5.3 to 12.4, median 8.9) than the group receiving total parenteral nutrition (12 patients). Assessment of recovery from myelosuppression was based on the length of time the absolute granulocyte count was below 500/mm3, the length of time the platelet count was below 40,000/mm3, the number of days the platelet count was below 20,000/mm3, and the number of blood transfusions required. There was no statistical difference in any of the parameters evaluated between the group that received total parenteral nutrition and the control group (p less than 0.05); granulocyte and platelet recovery and the difference in transfusion requirements favored the control group with marginal statistical significance (p = 0.05). The frequency of clinical infections was similar in the patients receiving total parenteral nutrition (five of 12) and in those receiving conventional oral nutrition (five of 15). Thus, although total parenteral nutrition could be safely administered in this severely myelosuppressed population, no benefit could be defined in recovery from bone marrow suppression or frequency of clinical infections.

Adolescent↗
PubMed1979

Abnormalities of zinc and copper during total parenteral nutrition.

Changes in serum zinc and copper levels were studied in 19 tumor bearing patients undergoing parenteral nutrition (TPN) for five to 42 days. Before initiation of intravenous feeding mean serum zinc and copper concentrations were within normal limits but during TPN levels decreased significantly below those measured prior to parenteral nutrition. During TPN nitrogen, zinc, and copper intake, urinary output and serum levels were studied prospectively in nine of these patients. These nine patients exhibited positive nitrogen retention based upon urinary nitrogen excretion, but elevated urinary zinc and copper excretion and lowered serum zinc and copper concentrations. Neither blood administration nor limited oral intake was consistently able to maintain normal serum levels of zinc or copper. Zinc and copper supplementation of hyperalimentation fluids in four patients studied for five to 16 days was successful in increasing serum zinc and copper levels in only two. The data obtained suggest that patients undergoing parenteral nutrition may require supplementation of zinc and copper to prevent deficiencies of these elements.

Adolescent↗
PubMed1978

Parenteral vitamin requirements during intravenous feeding.

Serum vitamin levels of 40 patients undergoing parenteral nutrition over a 5-to 42-day period were studied while the subjects received daily water-soluble and once weekly fat soluble vitamin formulations intravenously. Initial serum deficiencies of vitamins A, C, and folate were noted in a large portion of the severely malnourished population. At the replacement levels used in this study a small number of patients developed subnormal levels of vitamins A and D. Improvement in levels for vitamin C and folate were noted for most patients. Vitamin B12 deficiencies were not noted in any patient. Currently available commercial vitamin preparations can be used with safety in the parenterally nourished population and recommended guidelines for weekly infusion of both water and fat soluble vitamins are presented.

Adolescent↗
PubMed1977

Serum hepatic enzyme and bilirubin elevations during parenteral nutrition.

Serial liver enzyme and bilirubin concentrations were measured in 100 patients undergoing total parenteral nutrition. Between the eighth and tenth days, serum glutamic-pyruvic transaminase levels rose to 5.4 times pretotal parenteral nutrition levels; serum glutamic-oxalacetic transaminase, 2.8 times; bilirubin, 2.3 times, and lactic dehydrogenase, 1.5 times. These elevations were transient, lasting four to ten days. Biopsies of the liver taken during maximal elevations demonstrated marked periportal fatty change. A second elevation of serum glutamic-pyruvic transaminase, serum glutamic-oxalacetic transaminase, alkaline phosphatase and lactic dehydrogenase occurred in one-third to one-half of those patients receiving total parenteral nutrition for longer than a 20 day period. These elevations were more prolonged, and no biopsies were taken. Amino acid solutions contain conversion products of tryptophan, an amino acid that is unstable in the presence of the preservative sodium bisulfite which is added to all commercially available protein solutions. Infusion of these products into rats, either alone or as part of total parenteral nutrition solutions, resulted in periportal fatty change of the livers identical to that seen in our patients receiving total parenteral nutrition. A toxic effect of tryptophan conversion products in total parenteral nutrition solutions is proposed.

Alanine Transaminase↗
PubMedDate not supplied

Portal venous gas: detection by gray-scale and Doppler sonography in the absence of correlative findings on computed tomography.

Two cases are described in which portal venous gas (PVG) was detectable by ultrasound, but the liver appeared normal on computed tomography (CT). The finding of PVG was associated with ischemic bowel in one case but was a benign finding in the other case. The gray-scale and Doppler ultrasound findings associated with PVG are described. This case report illustrates two key points. First, ultrasound may detect gas within the portal venous system when CT is negative. Second, when PVG is detected on ultrasound, urgent clinical assessment followed by contrast-enhanced CT is indicated to assess for associated intestinal ischemia.

Aged↗
PubMedDate not supplied

Bile duct hamartomas (von Meyenburg complexes): value of MR imaging in diagnosis.

We present a case of a patient initially believed to have multiple liver metastases based on ultrasound and computed tomography findings in whom a diagnosis of multiple bile duct hamartomas (von Meyenburg complexes) was indicated after ultrasound-guided liver biopsy. Magnetic resonance imaging aided greatly in confirming the diagnosis of von Meyenburg complexes, thereby avoiding laparotomy and open liver biopsy.

Bile Duct Diseases↗