FC gamma receptor mediated phagocytosis by human neutrophil cytoplasts.

Neutrophils utilize Fcgamma Receptors (FcgammaR) to bind and internalize antibody coated cells or immune complexes. We have compared ultrastructurally FcgammaR-mediated phagocytosis by neutrophil cytoplasts (enucleated and granule-free neutrophils) prepared either by treatment with cytochalasin B (CB-cytoplasts) followed by ultracentrifugation or by brief heating at 45 degrees C in suspension followed by ultracentrifugation. The phagocytosis of antibody-coated erythrocytes (EIgG) or the internalization of crosslinked IgG complexes by cytoplasts prepared by brief heating was comparable to that of untreated neutrophils. In contrast, CB-cytoplasts bound but failed to internalize ElgG or crosslinked IgG complexes. Comparison of these two methods for the preparation of neutrophil cytoplasts may assist in clarifying the signal transduction requirements involved following ligand binding to FcgammaR which initiate phagocytosis.

Autoradiographic identification of a gastrin receptor on the human parietal cell.

Gastrin plays an important role in regulating gastric acid secretion and gastrointestinal mucosal growth but its cellular sites of action in man have not been determined. Using cryostat sections of gastric mucosal tissue we have identified (125I-gastrin binding followed by fixation-wet emulsion autoradiography) and characterized (125I-gastrin binding followed by counting) a gastrin receptor binding site in the human stomach. This site displayed binding characteristics similar to those observed in isolated cell systems: specifically, 125I-gastrin binding was rapid (t1/2 approximately 10 min at 37 degrees C), temperature-dependent (3.5 fold more radioligand bound at 22 degrees C than at 4 degrees C) and saturable. The binding of the radioligand was also tissue specific and was five-fold greater in the gastric body than in the gastric antrum and duodenum. In the autoradiographs, silver grains were localized only to parietal cells and not to other epithelial cell types. In the presence of 40 nM gastrin grains were no longer present over parietal cells demonstrating that these sites were both saturable and of high affinity. These data provide the first demonstration of gastrin binding sites (putative receptors) on parietal cells in the human stomach and suggest that gastrin acts directly on these cells to help regulate gastric acid secretion and/or mucosal growth.

Effective treatment for acute alkali injury to the esophagus using weak-acid neutralization therapy: an ex-vivo study.

OBJECTIVE: 1) To evaluate whether neutralization therapy with weak acid is effective in reducing observed histopathologic esophageal tissue injury secondary to liquid alkali, 2) to quantify the temperature change of the neutralizing agent, and 3) to determine the effect of interval to therapy on injury severity. METHODS: Harvested Sprague-Dawley rat esophagi were catheterized and placed in an oxygenated saline bath (37 degrees C) for 60 minutes and then fixed in 10% formalin. Nine groups (n = 10) were perfused with 50% sodium hydroxide (NaOH). Six of the groups were treated by neutralization with cooled orange juice (OJ) or cola that was maintained between 2 degrees C and 4 degrees C. This was performed at 0, 5, or 30 minutes after injury. In addition, two positive control groups were exposed to OJ or cola at time 0 and were not exposed to strong alkali. A third control group was exposed to strong alkali but was not administered any subsequent treatment. The temperature of the neutralizing agent was recorded prior to instillation and after exiting the esophagus. Blinded pathologic scoring of 0 (no injury) to 3 (severe) was recorded performed for six histopathologic categories: epithelial cell viability, cornified epithelial cell differentiation, granular cell differentiation, epithelial cell nuclei, muscle cells, and muscle cell nuclei. Comparisons were made among treatment times using the Kruskal-Wallis test and linear trend analysis. RESULTS: For each histopathologic category and each treatment mode, the Kruskal-Wallis test showed significant differences between the groups (p < 0.002) over time. Trend analyses showed more severe injury with delayed neutralization therapy (p < 0.05) for each treatment mode and histopathologic category. CONCLUSION: Early neutralization therapy with OJ or cola reduces acute esophageal alkali injury. Additional in-vivo study is needed before neutralization therapy is adopted for clinical use.

Histopathologic evaluation of the therapeutic efficacy of water and milk dilution for esophageal acid injury.

OBJECTIVE: To determine whether acid-induced injury to the esophagus is decreased by early dilutional therapy with water or milk. METHODS: A controlled in-vitro animal model for acid injury to the esophagus was carried out using esophagi harvested from 70 Sprague-Dawley rats of both sexes and weighing 250-350 g. One control and six experimental groups each containing ten esophagi were instilled with 1 mL of 0.5 normal solution of hydrogen chloride (N HCl). Dilution with water or milk was performed at 0, 5, or 30 minutes postinjury in the experimental groups. No dilution was performed with the control group. Specimens were maintained in an oxygenated saline bath for a 60-minute experimental period and then fixed in 10% formalin for histologic evaluation. Injury severity was rated by blinded histopathologic examination using scores of 0 (no injury), 1 (minor), 2 (moderate), and 3 (severe) for the histopathologic categories: cornified epithelial cells (CEs), granular cells (GCs), granular cell nuclei (GNs), and basal cells (BCs). Red blood cells were scored as positive or negative for lysis. RESULTS: The controls showed the most severe outcomes. Significant differences in injury occurred for all time periods and histopathologic categories, except for the GN/water and BC/milk histopathologic category/treatment groups. However, a linear trend analysis was significant for all histopathologic categories except BC. These analyses support decreased injury in the earlier treated groups. Injury severity was highest in the most superficial cell layer (CE). CONCLUSIONS: Emergency therapy with water or milk reduces acute acid injury to the esophagus. Earlier treatment is associated with decreased injury severity. This research supports the use of dilutional therapy with water or milk for acute acid injury to the esophagus.

Loin pain-hematuria syndrome with a distinctive vascular lesion and alternative pathway complement activation.

We describe a 48-year-old woman with loin pain-hematuria syndrome. Her renal abnormalities included conspicuous microaneurysmal and glomeruloid (plexiform) angiomatous changes. The deposition of both properdin and the C5b-9 complex, as well as the usual C3, in arterioles argues for complement activation. To our knowledge, neither of these features has been previously described. We speculate about the cause of loin pain-hematuria syndrome and note the uncommonness of this entity in the United States as opposed to Great Britain.

Therapeutic effects of water and milk for acute alkali injury of the esophagus.

STUDY BACKGROUND: Alkali ingestions cause progressive and devastating injury to the esophagus by liquefaction necrosis. However, the therapeutic efficacy of water or milk dilution for alkali-induced esophageal injury has not been determined. This study used our previously reported model of alkali-induced esophageal injury to evaluate the effectiveness of water and milk dilution. HYPOTHESIS: Early dilution with water or milk is efficacious in decreasing esophageal damage from alkali exposure. METHODS: The esopgagi of 75 Sprague-Dawley rats were harvested, and each end was cannulated with a 20-gauge catheter. Specimens were maintained in an oxygenated saline solution (at 37 degrees C) during a 60-minute experimental period and then fixed immediately in 10% Formalin solution for histologic examination. Esophagi from six experimental groups (total of 60) were perfused with 50% NaOH solution at time 0. Water or milk dilution was performed immediately at 0 minutes, 5 minutes after injury, and 30 minutes after injury. Blinded pathologic examination was performed using a score of 0 (no injury), 1 (minimal), 2 (moderate), or 3 (severe) for the following six histologic categories: epithelial viability, cornified epithelial cell differentiation, granular cell differentiation, epithelial cell nuclei, muscle cells, and muscle cell nuclei. RESULTS: Positive and negative controls showed expected outcomes. Significant progressions of injury over time were seen for every histologic category for both water and milk dilution. The injury scores for the milk-treated group at 0 minutes were less than or equal to the injury score for the water-treated group for all categories. However, these differences were significant only for the cornified epithelial cells. CONCLUSION: Early dilution therapy with water or milk reduces acute alkali injury of the esophagus and supports use of these forms of emergency treatment.

Effective treatment of acute alkali injury of the rat esophagus with early saline dilution therapy.

BACKGROUND: Controversy persists regarding the appropriate treatment of acute alkali injury to the esophagus. The current study establishes a controlled model of alkali esophageal injury and examines the efficacy of saline dilution therapy. STUDY HYPOTHESIS: Early saline dilution therapy effectively reduces esophageal injury resulting from acute alkali exposure. METHODS: The esophagi were harvested from 60 Sprague-Dawley rats. Each end was cannulated with a 20-gauge catheter. Specimens were maintained in an oxygen-perfused saline bath (37 C) during a 60-minute experimental period and then fixed immediately in 10% formalin solution for histologic examination. Three experimental groups (A, B, and C) were perfused with 50% NaOH solution at time zero. Treatment with saline perfusion was performed immediately in group A, five minutes after injury in group B, and 30 minutes after injury in group C. The positive control group D was perfused with saline at time zero. A negative control, group E, was perfused with 50% NaOH at time zero. This group did not receive subsequent treatment with saline. Pathologic examination was performed in a blinded fashion using a score of 0 to 3 (0, no injury; 1, minimal; 2, moderate; 3, severe) for seven histologic criteria: epithelial viability, extent of injury, cornified epithelial cell differentiation, granular cell differentiation, epithelial cell nuclei, muscle cells, and muscle cell nuclei. RESULTS: The positive control group demonstrated scores of zero. Nonparametric analysis showed a significant difference among treatment groups for each injury category. Trend analysis revealed a significant progression of injury for each category associated with time to treatment. Discriminant analysis indicated that the muscle cells category was the most useful category with which to distinguish injury among groups. CONCLUSION: In our model, saline lavage decreased objective evidence of esophageal injury after a severe alkaline exposure, and early therapy enhanced this beneficial effect.

Characterization of a bovine synovial fluid lubricating factor. III. The interaction with hyaluronic acid.

Although hyaluronate is not a boundary lubricant in cartilaginous and latex:glass bearings, a distinct interaction with purified synovial lubricating factor (PSLF) was demonstrated by three means: 1) enhancement of lubricating ability in an artificial test system; 2) viscometry; 3) electron microscopy. The interaction was of a physical rather than a specific chemical type; it varied with the degree of purification of PSLF and of hyaluronate. The interaction accounts for retention of the relatively small PSLF molecule (approximately 280 kDa) with the synovial mucin on a 0.22 microns filter. The data provide evidence that hyaluronate and PSLF act synergistically in the boundary lubricating activity of animal joints.

Plexiform neurofibromatosis of the liver and mesentery in a child.

Plexiform neurofibromatosis of the liver was recognized by needle biopsy of the liver in an 11-yr-old boy who had a 2-yr history of diarrhea, intermittent abdominal pain, failure to gain weight and progressive abdominal distention. Imaging studies demonstrated a large retroperitoneal mass; a laparotomy was performed. At surgery, the mesentery was greatly thickened by neurofibromas, and plexiform neurofibroma extended through the hilum of the liver. Light and electron microscopy demonstrated that in addition to the direct involvement by tumor, neural hyperplasia existed throughout the liver. The most distal ramifications of the portal spaces were filled with Schwann cells, bundles of unmyelinated nerves and perineurium-surrounded nerves containing myelinated and unmyelinated fibers. The ultrastructural findings were consistent with stimulation of proliferation of all the portal neural elements and tumoral tissue. The nontumoral response was more than simple hyperplasia because it appeared to result in fibrotic changes in the most involved areas and active breaching of the limiting plate with destruction of hepatocytes and collagen deposition throughout the liver.

Interaction between Borrelia burgdorferi and endothelium in vitro.

During the pathogenesis of Lyme disease, Borrelia burgdorferi spreads hematogenously from the site of a tick bite to several tissues throughout the body. The specific mechanism of spirochete emigration is presently unknown. Using cultured human umbilical vein endothelial cells, we found that Borrelia burgdorferi bound to the endothelial cells and to the subendothelial matrix. Low passage isolates adhered 22-30-fold greater than a strain maintained in culture continuously. Spirochete binding to subendothelial matrix was inhibited 48-63% by pretreatment of the matrix with anti-fibronectin antiserum. Spirochete migration across endothelial monolayers cultured on amniotic membrane was increased when the monolayers were damaged by chemical or physical means. Electron microscopic examination of spirochete-endothelial interactions demonstrated the presence of spirochetes in the intercellular junctions between endothelial cells as well as beneath the monolayers. Scanning electron microscopy identified a mechanism of transendothelial migration whereby spirochetes pass between cells into the amniotic membrane at areas where subendothelium is exposed.

Polyaspartic acid protects against gentamicin nephrotoxicity in the rat.

Polyamino acids including polyaspartic acid (PAA) have been reported to provide protection against the development of aminoglycoside-induced nephrotoxicity in the rat as assessed by histopathology scoring. We sought to confirm and extend these observations by determining whether PAA also prevented functional and biochemical lesions of gentamicin-nephrotoxicity in an animal model studied extensively in our laboratory. Rats were given injections of: 1) 0.9% NaCl at 2.5 ml/kg b.wt. per day; 2) PAA (mol.wt. 15,000) at 500 mg/kg per day; 3) gentamicin at 100 mg/kg per day or 4) gentamicin at 100 mg/kg per day and PAA at 500 mg/kg per day for 6 days. Rats injected with gentamicin exhibited: 1) increased urinary excretion of the brush border membrane enzyme alanine aminopeptidase and the lysosomal enzyme N-acetyl-beta-d-glucosaminidase after the first injection; 2) increased total phospholipid and malondialdehyde but decreased catalase activity in the renal cortex; 3) elevation of serum creatinine and depression of creatinine clearance and 4) extensive proximal tubular cell necrosis all determined 24 hr after the last injection of gentamicin. Rats injected with gentamicin plus PAA also exhibited increased urinary excretion of alanine aminopeptidase not different in magnitude from that of rats injected with gentamicin alone, whereas N-acetyl-beta-d-glucosaminidase rose more slowly and returned to base line by day 4. Total renal cortical phospholipid was elevated to the same extent in the two groups. Malondialdehyde was not different from control and catalase activity was significantly less depressed in rats injected with gentamicin plus PAA.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulation of matrix formation in rabbit chondrocyte cultures by ascorbate. 1. Effect of ascorbate analogs and beta-aminopropionitrile.

The most consistent effects of 0.2 mM L-ascorbate on monolayer cultures of rabbit articular chondrocytes were a diversion of incorporated radiosulfate into a pericellular matrix and enhancement of cell proliferation. Only with certain batches of fetal bovine serum (FBS) was there a cell-for-cell increase of proteoglycan synthesis. These actions increased as the cell inoculum rose from 0.5 to 2 x 10(5) cells/T25 flask. Maximal effects of ascorbate and D-isoascorbate were found over a range of 0.05-0.2 mM. L-Dehydroascorbic acid was less effective than either, and no stimulatory action was exerted by L-cysteine, glutathione, dithiothreitol, methylene blue, or phenazine methosulfate. Ascorbate increased the hypro:pro ratio of newly synthesized proteins. beta-Aminopropionitrile (1 mM) reduced the proportion of [3H]hydroxyproline and [35S]O4-proteoglycans in the ascorbate-supplemented matrix 31 and 7%, respectively. In corresponding electronmicrographs, the number of pericellular filaments was reduced. We conclude: (a) Ascorbate has a general anabolic effect on chondrocytes in culture and enhances matrix assembly through mechanisms other than its redox function; (b) deposition of proteoglycans in the matrix is not simply the result of mechanical entrapment by allysine- or hydroxyallysine-derived cross-linking of collagen; and (c) contradictory reports on the subject result from variations in the serum employed, inoculum density, and concentration of ascorbate.

Fc-mediated endocytosis by human neutrophils. Ultrastructural studies.

Fc Receptors (FcR) mediate the binding and uptake by polymorphonuclear leukocytes (PMN) of antibody-coated particles and soluble immune complexes. We have studied Fc-mediated endocytosis by PMN ultrastructurally using a gold-conjugated monoclonal antibody (3G8) to block or to mark the location of FcR. Phagocytosis of antibody-coated erythrocytes (EIgG) was initiated rapidly after binding to discrete foci on the PMN plasma membrane. After the phagocytosis of EIgG, we examined the distribution of FcR remaining on the PMN plasma membrane. 3G8-Colloidal gold continued to bind to PMN after ingestion of up to three EIgG, demonstrating that all PMN FcR are not utilized during a brief phagocytic event. The endocytosis of soluble immune complexes was examined by labeling plasma membrane-bound rabbit immune complexes with goat anti-rabbit IgG conjugated to colloidal gold. Gold was found in clusters randomly distributed over the plasma membrane at 4 degrees C. When cells were warmed to 37 degrees C, numerous endocytic vesicles were observed as early as 2.5 minutes after warming. After 30 minutes at 37 degrees C, large vesicles, 1 micron in diameter, were found to contain 20 to 30 gold particles. The endocytosis of 3G8 was also examined using colloidal gold. After binding of 3G8-gold at 4 degrees C, clusters of large vesicles, up to 2 micron in diameter, were rapidly formed at 37 degrees C.

Induction of nephrotoxicity by high doses of gentamicin in diabetic rats.

Rats with streptozotocin-induced diabetes mellitus (DM) are resistant to aminoglycoside (AG) nephrotoxicity presumably because of defective transport and accumulation of drug by proximal tubular cells. To test this hypothesis we injected DM rats with saline or with gentamicin, 100, 200, and 400 mg/kg per day for 6 days, to determine if the renal cortical concentration of gentamicin could be raised to toxic levels. Nephrotoxicity was assessed by monitoring for evidence of accelerated lipid peroxidation in the renal cortex, for elevation of the serum creatinine concentration, and for evidence of proximal tubular cell injury and necrosis by light and electron microscopy. At 100 mg/kg per day renal cortical gentamicin was 454 +/- 85 micrograms/g. Except for an increase in renal cortical phospholipids these rats manifested no evidence of accelerated lipid peroxidation or elevation of serum creatinine. At 200 mg/kg per day renal cortical gentamicin rose to 636 +/- 20 micrograms/g. These rats manifested mild functional and morphological evidence of toxicity. At 400 mg/kg renal cortical gentamicin rose to 741 +/- 43 micrograms/g. These rats developed severe nephrotoxic injury as manifested by a marked increase of lipid peroxidation evident by an increase of malondialdehyde from a control level of 0.48 +/- 0.02 to 1.72 +/- 0.12 nmole/mg protein, a shift from unsaturated to saturated fatty acids esterified in renal cortical phospholipids, depression of superoxide dismutase and catalase, and a shift from reduced to oxidized glutathione. The serum creatinine rose from a baseline level of 0.24 +/- 0.01 to 0.46 +/- 0.05 mg/dl. Light and electron microscopy revealed enlarged lysosomes distended with typical myeloid bodies and extensive proximal tubular cell necrosis. These observations provide compelling evidence in support of the view that the resistance of DM rats to AG nephrotoxicity is causally linked to the low rate of drug uptake by renal proximal tubular cells. When the renal cortical concentration reaches a critical level, it elicits a pattern of toxic injury indistinguishable from that of nondiabetic rats. Thus, there is nothing inherent to the diabetic state that prevents AGs from causing their usual adverse effects on the metabolism of renal proximal tubular cells once they gain access in sufficient quantity into these cells.

Failure of inhibition of lipid peroxidation by vitamin E to protect against gentamicin nephrotoxicity in the rat.

We tested the hypothesis that accelerated lipid peroxidation, possibly at the level of the lysosome, is linked causally to the pathogenesis of aminoglycoside nephrotoxicity by investigating whether administration of vitamin E would inhibit lipid peroxidation and prevent or ameliorate gentamicin-induced proximal tubular cell injury. Five groups of rats were injected with either saline, vitamin E (600 mg/kg per day) for 6 days, gentamicin (100 mg/kg per day) for 6 days, vitamin E for 6 days plus gentamicin for 6 days or vitamin E for 12 days and gentamicin for the last 6 days. Gentamicin alone induced a 16% increase in renal cortical phospholipids; vitamin E had no significant effect on this change. Gentamicin alone caused accelerated lipid peroxidation evident by a doubling of renal cortical malondialdehyde to 1.23 nmol/mg protein, and a sharp decline of esterified polyunsaturated fatty acids, especially arachidonic acid which fell 43%. These changes were accompanied by depressions of superoxide dismutase, catalase, and total glutathione and a shift from reduced to oxidized glutathione. Concurrent treatment of rats with vitamin E plus gentamicin for 6 days had no significant effect on the gentamicin-induced alterations of malondialdehyde, superoxide dismutase, catalase or the glutathione cascade; however, the shift from polyunsaturated to saturated fatty acids was largely reversed. In rats pretreated with vitamin E for 6 days, gentamicin failed to raise renal cortical malondialdehyde above that of saline-treated rats. The changes in esterified fatty acids were prevented almost entirely, and there were no significant alterations from control of the glutathione cascade. The depressions of superoxide dismutase and of catalase, however, were not reversed. Vitamin E did not affect the amount of gentamicin accumulated in renal cortex nor did it prevent the gentamicin-induced rise of serum creatinine. Examination of renal cortex by light and electron microscopy revealed that vitamin E did not prevent or even reduce the severity of gentamicin-induced proximal tubular cell lesions and necrosis. These results confirm those we obtained in a previous study with the antioxidant diphenyl-phenylenediamine. The observation that inhibition of lipid peroxidation by two distinct antioxidants failed to prevent proximal tubular cell injury and renal dysfunction associated with gentamicin administration leads us to conclude that lipid peroxidation is a consequence and not a cause of gentamicin-induced nephrotoxicity.

Albumin modulates lateral assembly of fibrin polymers: evidence of enhanced fine fibril formation and of unique synergism with fibrinogen.

We identified a new property of human albumin. It enhances formation of fine fibril (or leptofibril) structures during fibrin gelation, and by nephelometric and electron microscopic measurements, this property is independent of and synergistic with that of fibrinogen. We examined fibrin aggregation using physiologic temperatures and pH and albumin:fibrin concentration ratios below those at which the known accelerating effect on fibrin aggregation occurs. An albumin concentration dependent decrease in gel turbidity maxima was consistently demonstrable in buffers containing or lacking (2-5 mM) CaCl2. This decrease was shown to be induced by albumin preparations which had been exposed to 2 mM ethylene-diaminetetraacetate disodium salt (EDTA), dialyzed, and tested in EDTA-free buffer. A delay in the onset of aggregation was also shown in calcium-lacking buffers by use of either reaggregating fibrin or fibrinogen aggregated with low (0.01-0.05 unit/mL) thrombin concentrations. Rates of fibrin aggregation as well as those of fibrinopeptide release were not affected by albumin, and the decrease in gel absorbance was demonstrable when solubilized fibrin was reaggregated at all final fibrin concentrations (0.2-4 microM) examined. Computed from wavelength dependence turbidity measurements (1 microM fibrin, I = 0.20), albumin decreased the average mass:length ratio from 8.24 X 10(11) to 4.26 X 10(11) daltons/cm, or from that of an approximately six to a three protofibril-thick strand. It also decreased the mean fibril radius from 48.5 to 36.4 nm but had no effect on fibril density. Electron microscopic measurements of cross-sectional fibril widths, performed on sections of glutaraldehyde-fixed gels, disclosed differences between albumin-containing and control gels which were significant by chi 2 analysis (P greater than 0.001). Fibril groups of 7-20- and 21-40-nm width together comprised 77% of fibrils formed in the presence of albumin (n = 251) compared to 30% of controls (n = 309). Conversely, coarser fibrils of 41-60- and 61-97-nm width together comprised 23% of fibrils formed in the presence of albumin and 70% of controls. This albumin effect was demonstrable by use of different monomeric albumin preparations including defatted, undefatted (unexposed and exposed to 60 degrees C, 10 h), chromatographically [gel exclusion and (diethylaminoethyl)cellulose] pure, S-(carboxymethyl)albumin, and S-(N-ethylsuccinimidyl)albumin. Chromatographically isolated albumin oligomers lacked this property, suggesting that a specific site(s) on albumin was (were) required.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of diphenyl-phenylenediamine on gentamicin-induced lipid peroxidation and toxicity in rat renal cortex.

The hypothesis that lipid peroxidation is linked causally to the pathogenesis of aminoglycoside nephrotoxicity was tested by determining whether administration of the antioxidant, diphenyl-phenylenediamine (DPPD) would inhibit lipid peroxidation and ameliorate gentamicin-induced proximal tubular cell injury. Rats were injected with saline, gentamicin or gentamicin plus DPPD for 4 days and were sacrificed 48 hr later. Gentamicin increased malondialdehyde in renal cortex from a control level of 0.65 +/- 0.04 to 1.01 +/- 0.03 nmol/mg of protein, P less than .01; it was reduced to 0.20 +/- 0.03 by DPPD, P less than .01 compared to control. Arachidonic acid comprised 27.6 +/- 0.5% of the fatty acid in renal cortical phospholipid of control rats. Gentamicin lowered arachidonic acid to 16.7 +/- 0.9%, P less than .01, and promoted a shift toward saturated fatty acids. DPPD reversed these changes. Gentamicin depressed catalase activity from a control value of 0.211 k/min to 0.154 +/- 0.008 k/min, P less than .01. DPPD depressed catalase further to 0.095 +/- 0.066 k/min, P less than .01. Total glutathione and reduced glutathione were depressed whereas the fraction of total glutathione in the oxidized state was augmented by gentamicin. These changes were prevented by DPPD. The renal cortical phospholipidosis induced by gentamicin was not altered by DPPD. The increased urinary excretions of alanine aminopeptidase and N-acetyl-beta-glucosaminidase induced by gentamicin were augmented further by DPPD. In DPPD rats serum creatinine (0.45 +/- 0.04 mg/dl) was higher (P less than .01) than that of gentamicin rats (0.35 +/- 0.01 mg/dl), which was higher (P less than .01) than that of control rats (0.26 +/- 0.01 gm/dl).(ABSTRACT TRUNCATED AT 250 WORDS)

Gallbladder dyskinesia in chronic acalculous cholecystitis.

To test the hypothesis that there is an early stage of cholesterol gallstone formation in man characterized by symptoms of chronic cholecystitis, poor gallbladder emptying, and biliary cholesterol crystals, we studied cholecystokinin-stimulated gallbladder emptying by DISIDA scintigraphy and examined bile for cholesterol crystals in symptomatic patients with normal oral cholecystography and gallbladder sonography. Of 36 patients studied, 16 had biliary cholesterol crystals; their mean 30-min gallbladder ejection fraction was 25.9 +/- 14.8%. Among the 20 patients without crystals, the mean ejection fraction was 60.3 +/- 23.3%. Fifteen patients, 11 with crystals and four without, had cholecystectomy because of persistent symptoms. All with crystals preoperatively and three without had chronic cholecystitis histologically. One patient without crystals had normal histology. We conclude that poor gallbladder contractility, well-established as an etiologic factor in animal models of cholesterol cholelithiasis, is now linked to acalculous cholecystitis, an early stage of human cholesterol cholelithiasis.

Detection of human pancreatic adenocarcinomas by histochemical staining with monoclonal antibody AR1-28.

Hybridoma AR1-28 [Chin and Miller, Cancer Res 45:1723-1729, 1985] was produced using splenocytes from BALB/c mice which had been immunized with human pancreatic adenocarcinoma cell line RWP-1 [Dexter et al, Cancer Res 42:2705-2714, 1982]. This antibody cross reacted with the RWP-2 cell line. AR1-28, an IgG1 antibody, stained the membranes of five (RWP-1, RWP-2, BxPC-3, HPAF-2, and T3M4) out of ten human pancreatic tumor cell lines by immunofluorescence techniques. Electron microscopy on RWP-2 cells, stained by indirect immunoperoxidase, confirmed a membrane location for the AR1-28 antigen. Twenty-three of the 27 clinical specimens (83%) of formalin-fixed, paraffin-embedded pancreatic cancers tested were positive. Varying intensities of staining were observed and were related to the degree of differentiation achieved by the tumor: poorly differentiated tumors showing the least staining while well-differentiated tumors showed the greatest intensity of staining in a predominantly apical location. Immunoblotting showed that AR1-28 reacts with a 200,000-dalton antigen present in extracts of RWP-1 and RWP-2 cells. This monoclonal antibody may be useful in the classification of pancreatic tumor cells.

Interactions of phagocytes with the Lyme disease spirochete: role of the Fc receptor.

The phagocytic capacity of murine and human mononuclear and polymorphonuclear phagocytes (including peripheral blood monocytes and neutrophils), rabbit and murine peritoneal exudate cells, and the murine macrophage cell line P388D1 against the Lyme disease spirochete was studied. All of these cells were capable of phagocytosing the spirochete; phagocytosis was measured by the uptake of radiolabeled spirochetes, the appearance of immunofluorescent bodies in phagocytic cells, and electron microscopy. Both opsonized and nonopsonized organisms were phagocytosed. The uptake of opsonized organisms by neutrophils was blocked by a monoclonal antibody specific for the Fc receptor and by immune complexes; these findings suggested that most phagocytosis is mediated by the Fc receptor. Similarly, the uptake of opsonized organisms by human monocytes was inhibited by human monomeric IgG1 and by immune complexes. These results illustrate the role of immune phagocytosis of spirochetes in host defense against Lyme disease.