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M J Becich

Publications and source records attributed to M J Becich.

66 records · Page 4Linked to original sources

Safety and efficacy of laparoscopic cholecystectomy using monopolar electrocautery in the porcine model.

Recent reports suggest that laparoscopic laser cholecystectomy may become the preferred therapy for symptomatic cholelithiasis. To assess the efficacy and safety of this technique, using monopolar electrocautery instead of laser for the gallbladder dissection, laparoscopic cholecystectomy was performed on 11 pigs. Under general anesthesia, a pneumoperitoneum was established, and four sheaths were placed into the abdomen for introduction of instruments. Using video laparoscopic guidance, the cystic duct and artery were isolated, clipped, and divided. Monopolar electrocautery was used to dissect the gallbladder from its fossa. Five animals were sacrificed immediately, without visible evidence of injury to the bile ducts, liver, or intestine. The remaining six pigs were allowed to recover. One animal died 10 days postoperatively due to adhesive small bowel obstruction. The remainder survived in good health until sacrifice at 1 month. Histologic examination of the gallbladder bed and liver revealed no evidence of ongoing local hepatocyte destruction or chronic cholestasis. Cholangiography demonstrated the bile ducts to be intact. Mean (+/- SEM) total serum bilirubin (TB), alkaline phosphatase (AP), and glutamic oxalacetic transaminase (SGOT) at the time of sacrifice were similar to nonoperated swine (n = 10): TB, 0.12 +/- 0.02 versus 0.11 +/- 0.01 mg/dl; AP, 175 +/- 23 versus 162 +/- 10 IU/L; SGOT, 37 +/- 4 versus 55 +/- 7 IU/L, respectively (p > 0.05). We conclude that laparoscopic cholecystectomy can be performed using monopolar electrocautery without significant acute injury to the liver, bile ducts, or surrounding viscera. Furthermore, the porcine model can be utilized by surgeons to attain competence in this technique prior to instituting clinical application in humans.

Alkaline Phosphatase↗

Ligand-specific isolation of endosomes and lysosomes using superparamagnetic colloidal iron dextran glycoconjugates and high gradient magnetic affinity chromatography.

We have developed a ligand-specific method for the visualization, isolation, and biochemical characterization of cell surface and intracellular membranes mediating endocytic transport. Iron dextran particles (FeDex) bearing either covalently conjugated galactosyl bovine serum albumin (GalBSA/FeDex) or asialofetuin (ASF/FeDex) are bound by the asialoglycoprotein receptor (ASGP-R) of HepG2 cells and transported to lysosomes with kinetics indistinguishable from those of free GalBSA or ASF. FeDex particles, which have a 3 to 5 nm electron-dense colloidal iron core, can be visualized by electron microscopy. Following incubation of GalBSA/FeDex with HepG2 cells at 37 degrees C, FeDex particles are seen at the cell surface, in endosomes, and in lysosomes. Surface membrane and intracellular organelles bearing a sufficient number of FeDex particles can be efficiently isolated from disrupted cells by high gradient magnetic affinity chromatography (HIMAC). Plasma membranes and endosomal/lysosomal membranes isolated by HIMAC are 35 to 40-fold enriched for GalBSA/FeDex or ASF/FeDex relative to the postnuclear supernatant. Alkaline phosphodiesterase I (APDE) and galactosyltransferase are each enriched 8-fold in the plasma membrane fraction prepared by HIMAC whereas neither beta-galactosidase nor glucose-6-phosphatase are detected in this fraction. The intracellular membrane fraction, containing both endosomes and lysosomes, is enriched for galactosyltransferase and beta-galactosidase but not for APDE or glucose-6-phosphatase. Use of FeDex conjugates in conjunction with HIMAC provides an effective method for ligand-specific isolation of membranes and correlation of morphological and biochemical characteristics.

Animals↗

Wheat germ agglutinin is selectively transported to multivesicular bodies.

Colloidal iron dextran particles bearing wheat germ agglutinin (WGA/FeDex) were bound by glycoconjugates expressed at the surface of HepG2 cells. Bound WGA/FeDex was internalized when cells were incubated at 37 degrees C and accumulated in intracellular structures which have the same buoyant density as the plasma membrane when examined on Percoll density gradients. The intracellular structures containing WGA/FeDex were identified as multivesicular bodies (MVB) by transmission electron microscopy. WGA/FeDex was not transported to lysosomes nor did it interfere with uptake and transport of GalBSA to lysosomes by the asialoglycoprotein receptor. WGA/FeDex was seen predominantly in non-coated invaginations at the cell surface, suggesting it may enter cells at a different site than GalBSA/FeDex. Highly enriched plasma membranes and MVBs containing superparamagnetic [125I]WGA/FeDex particles were prepared by high gradient magnetic affinity chromatography (HIMAC). Plasma membranes prepared by HIMAC were enriched 30-fold for [125I]WGA/FeDex, 15-fold for alkaline phosphodiesterase I, and 9-fold for galactosyltransferase relative to the crude post-nuclear homogenate and consisted entirely of plasmalemmal sheets. Intracellular structures containing WGA/FeDex were enriched 35-fold for [125I]WGA/FeDex, 10-fold for alkaline phosphodiesterase I, and 10-fold for galactosyltransferase but did not contain lysosomal beta-galactosidase. WGA/FeDex has a different ultimate destination in HepG2 cells than ligands internalized by the asialoglycoprotein receptor and can be used to obtain highly enriched plasma membranes and MVBs from cultured cells.

Animals↗

Both tissue and serum phospholipases release rat intestinal alkaline phosphatase.

Rat intestinal alkaline phosphatase (IAP) is unique among the brush-border membrane enzymes in that it is released bidirectionally (lumen and blood) and exists in either soluble (serum) or particulate (cellular) form. To elucidate the mechanism of membrane release, we examined the effects of phosphatidylinositol-specific phospholipase C (PtdIns-PLC) and serum anchor-specific phospholipase D (PLD) on the solubility of the various tissue forms of IAP. The "solubility" of cytosol IAP could be explained in part by intracellular PtdIns-PLC activity, detected by production of acidic IAP isomers, and by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA)-sensitive PtdIns hydrolysis. Contamination with serum (abundant with anchor-specific PLD) was responsible for the complete or partial solubilization of IAP that was found during processing of light mucosal scrapings. Anchor-specific PLD activity was increased after fat feeding, and the IAP released did not react with antiserum that recognizes the PtdIns-PLC-released phospholipid portion of trypanosomal variable surface glycoprotein. These data are consistent with the hypothesis that, after secretion from the enterocyte bound to a phospholipid-rich membranous particle, IAP release into serum is mediated by serum anchor-specific PLD. The soluble forms of IAP in the lumen and the cytosol fraction appear to be due to a combination of endogenous PtdIns-PLC activity and anchor-specific PLD contamination that occurs during cell fractionation.

Alkaline Phosphatase↗

Incidence and prognostic significance of lymphatic and vascular invasion in radical prostatectomy specimens.

A review of 55 radical prostatectomy specimens from patients with clinically localized carcinoma of the prostate was performed. Blinded review of slides was performed by a single pathologist and urologist. Criteria for invasion were encroachment by tumor of the lymphatic or vascular lumen and evidence of reaction around or in the lymphatic or vascular channel. Notation was made of the degree and location of lymphatic and vascular invasion. All patients had a minimum of 5 years of follow-up. Twenty-one of 55 (38%) patients either had lymphatic or vascular invasion, and seven (13%) had both findings. In the majority of these patients the degree of invasion was rare (71%), while multifocal (19%) and diffuse (10%) involvement were seen less frequently. Nine patients experienced either progression of their tumors or death from disease. Those patients with evidence of lymphatic or vascular invasion had a fourfold greater incidence of progression and or death. However, the presence of lymphatic or vascular invasion was clearly related to both tumor grade and stage, and multivariate statistical analysis demonstrated that its prognostic significance was dependent upon tumor grade.

Carcinoma↗

Effect of low osmolar, ionic and nonionic, contrast media on the cytologic features of exfoliated urothelial cells.

The effect of low osmolar, ionic and nonionic, contrast media on the cytologic features of exfoliated urothelial cells were measured in vitro and compared to those induced by standard, high osmolar radiographic contrast media. The low osmolar agents were found to induce no significant adverse effects on the cytologic features of the urothelial cells, whereas the ionic agents clearly distorted certain cytoplasmic and nuclear features. These findings may support the use of low osmolar nonionic agents for retrograde urography if posturographic cytologic studies are contemplated.

Contrast Media↗

Immunocytochemical localization of exocrine enzymes in rat pancreatic acinar carcinoma.

Ten pancreatic secretory proteins have been demonstrated in differentiated pancreatic acinar carcinoma cells by the protein A-gold immunocytochemical approach. The high resolution of the technique has allowed for the localization of the different proteins in the cellular compartments involved in protein secretion: RER, Golgi and secretory granules. The quantitative evaluation of the labeling for amylase has demonstrated the presence of an increasing gradient in the intensity from the RER to the Golgi and to the secretory granules which may reflect the process of protein concentration along the secretory pathway. These results, together with those obtained using the pulse-labeling autoradiographic approach, demonstrate that differentiated acinar carcinoma cells are capable of processing secretory proteins. When intensities of labeling obtained for different proteins on acinar carcinoma cells were compared to those obtained on normal pancreatic acinar cells, major differences were observed for some proteins. In addition, studies performed on the pancreatic tissue of the tumor-bearing animals have shown the presence of morphological alterations in the acinar cells.

Animals↗

Intracellular transport and storage of secretory proteins in relation to cytodifferentiation in neoplastic pancreatic acinar cells.

The pancreatic acinar carcinoma established in rat by Reddy and Rao (1977, Science 198:78-80) demonstrates heterogeneity of cytodifferentiation ranging from cells containing abundant well-developed secretory granules to those with virtually none. We examined the synthesis intracellular transport and storage of secretory proteins in secretory granule-enriched (GEF) and secretory granule-deficient (GDF) subpopulations of neoplastic acinar cells separable by Percoll gradient centrifugation, to determine the secretory process in cells with distinctly different cytodifferentiation. The cells pulse-labeled with [3H]leucine for 3 min and chase incubated for up to 4 h were analyzed by quantitative electron microscope autoradiography. In GEF neoplastic cells, the results of grain counts and relative grain density estimates establish that the label moves successively from rough endoplasmic reticulum (RER) leads to the Golgi apparatus leads to post-Golgi vesicles (vacuoles or immature granules) leads to mature secretory granules, in a manner reminiscent of the secretory process in normal pancreatic acinar cells. The presence of approximately 40% of the label in association with secretory granules at 4 h postpulse indicates that GEF neoplastic cells retain (acquire) the essential regulatory controls of the secretory process. In GDF neoplastic acinar cells the drainage of label from RER is slower, but the peak label of approximately 20% in the Golgi apparatus is reached relatively rapidly (10 min postpulse). The movement of label from the Golgi to the post-Golgi vesicles is evident; further delineation of the secretory process in GDF neoplastic cells, however, was not possible due to lack of secretory granule differentiation. The movement of label from RER leads to the Golgi apparatus leads to the post-Golgi vesicles suggests that GDF neoplastic cells also synthesize secretory proteins, but to a lesser extent than the GEF cells. The reason(s) for the inability of GDF cells to concentrate and store exportable proteins remain to be elucidated.

Animals↗

Carbamylcholine stimulation of protein secretion in pancreatic acinar carcinoma of rat.

Pancreatic acinar carcinoma fragments, pulse-chase labeled with [3H]-leucine, responded to carbamylcholine chloride by increased secretion of [3H]leucine-labeled protein into external buffer medium. Secretion of labeled protein by the carcinoma fragments increased in concentration-dependent fashion between 10(-8) -10(-5) M carbamylcholine, was completely inhibited at 4 degrees C, and was accompanied by an equivalent increase in the secretion of preformed amylase. A maximally effective carbamylcholine concentration of 10(-5) M was observed for both carcinoma fragments and normal pancreas lobules. However, the maximal rate of protein secretion by the carcinoma fragments was only approximately one-fifth the rate determined for the normal pancreas lobules. This modest secretory response indicates a population of partially differentiated cells in the pancreatic acinar carcinoma which secrete less enzyme than fully differentiated adult pancreatic acinar cells. Secretory responsiveness can be utilized as a quantitative acinar cell response in studies on differentiation in pancreatic carcinoma.

Amylases↗

Quantitative computer-assisted image analysis of suction biopsy in pediatric gastroesophageal reflux.

Gastroesophageal reflux is a disorder with well-characterized histopathological features in the adult, but the incidence and pathogenesis of epithelial injury in children are poorly understood. Esophageal suction biopsies from 80 infants exhibiting symptoms of reflux were studied by computer-assisted image analysis and the results compared to routine histological scoring. The histological features evaluated were the number of intraepithelial lymphocytes and eosinophils, papillary height, interpapillary basal cell height, and a novel measure "integrated basal cell height." We quantitatively evaluated these histological criteria by computer-assisted image analysis and compared these results to four subjective grades of esophagitis: low, mild, moderate and high. In this report we now describe this quantitative histopathologic method for the evaluation of pediatric esophageal biopsies. Utilizing this method we demonstrate that both inter- and intra-observer variability were sufficiently low to stratify the mucosal changes reliably into at least four categories. The reliability of this objective analytic technique will permit studies into the disease progression and regression in pediatric reflux esophagitis.

Biopsy↗