beta-Lactam antibiotic-induced release of free endotoxin: in vitro comparison of penicillin-binding protein (PBP) 2-specific imipenem and PBP 3-specific ceftazidime

The relative effects of two beta-lactam antibiotics, penicillin-binding protein (PBP) 2-specific imipenem and PBP 3-specific ceftazidime, upon in vitro induction of lipopolysaccharide (LPS) release were investigated against smooth- and rough-LPS mutant isolates of Pseudomonas aeruginosa. Free LPS liberated from both isolates are 10- to 40-fold higher for ceftazidime-exposed cultures than control or imipenem-treated cultures after 4-8 h at 35 degrees C despite equivalent MICs. Lethalities of filtrates in mice correlated with in vitro endotoxin assay results. Sub-MIC levels of ceftazidime induced filamentation and LPS release without significant bacterial lysis. Amounts released not only matched the quantities achieved at inhibitory concentrations (e.g., 1-, 2-, and 50-times MIC) of ceftazidime but significantly exceeded levels of LPS liberated by exposure to imipenem, less than or equal to 100 times its MIC. Sub-MIC levels of imipenem released relatively small amounts of free LPS while reducing colony counts approximately 2 logs more than equivalent amounts of ceftazidime after 2 h. Data suggest that ceftazidime-induced filamentation releases larger quantities of bioreactive LPS than nonfilamentous fast-lysing imipenem.

Further examination of the equity sensitivity construct

This study was conducted to investigate whether a measure of equity sensitivity can predict individual reactions to inequity. The equity sensitivity construct suggests that there are three categories of individual preferences for equity: (1) benevolent individuals prefer their input:outcome ratios be less than those of their comparison others, (2) equity sensitive individuals prefer their input:outcome ratios be equal to those of comparison others, and (3) entitled individuals prefer their input:outcome ratios be higher than those of comparison others. To identify their appropriate equity sensitivity category, 639 undergraduate students and 119 fast-food restaurant employees were administered the Equity Sensitivity Instrument. These subjects were then asked to react to two underreward/overreward scenarios. Analysis indicates that equity sensitivity groups generally exhibit reactions in the direction predicted by the study; however, some inconsistencies require further study. Research should examine why some reactions to inequity are chosen over others and how the longitudinal effects of a work relationship may influence one's reactions to inequity.

Glycolipids as host resistance stimulators

6-(5-Cholesten-3 beta-yloxy)hexyl 1-thio-beta-D-mannopyranoside (L-644,257) enhances natural host resistance in cyclophosphamide-treated mice against Pseudomonas aeruginosa in a dose-dependent manner. It is active sc, im, and ip but not orally. L-644,257 is substantially more protective against P. aeruginosa than its alpha anomer. The beta-L-fucose glycolipid is more effective when given im and ip than sc. The lactose and beta-D-glucose glycolipids were only marginally effective to nonprotective. The 17 beta-steroidal side chain of L-644,257 can be modified without substantial loss of protective activity.

Steroidal glycolipid, L-644,257, is a potent enhancer of nonspecific host resistance

A steroidal glycolipid that enhances the nonspecific cellular response to opportunistic infection in an immunocompromised host has been discovered. A dose dependent response with 6-(5-cholesten-3 beta-yloxy)hexyl 1-thio-beta-D-mannopyranoside, L-644,257, was observed against several infective agents including bacterial, fungal, and viral pathogens in cyclophosphamide-treated mice. A mechanism for this protective action is proposed.

Human monoclonal antibodies that protect mice against challenge with Pseudomonas aeruginosa

Lymphocytes from healthy volunteers and from cystic fibrosis patients were transformed with Epstein-Barr virus and cultured at a limiting dilution to generate lymphoblastoid cell lines that secreted human monoclonal antibodies specific for lipopolysaccharide (LPS) from Pseudomonas aeruginosa. Three cell lines (RM5, FDD7, and 11F9) produced immunoglobulin M (IgM) antibody species that reacted specifically with P. aeruginosa Fisher immunotypes 2, 4, and 5, respectively, and with LPS extracted from these immunotypes. A fourth cell line (9H10) produced a single IgM antibody species that recognized P. aeruginosa immunotypes 3, 6, and 7 and LPS extracted from them. Monoclonal antibodies secreted by cell lines RM5, FDD7, and 11F9 protected neutropenic mice prophylactically against challenge with P. aeruginosa immunotypes 2, 4, and 5, and those secreted by 9H10 protected against P. aeruginosa immunotypes 3 and 6 but did not protect against immunotype 7. In vivo experiments indicated that antibodies protected mice against infection by increasing the rate of bacterial clearance.

X-linked immunodeficient mice as a model for testing the protective efficacy of monoclonal antibodies against Pseudomonas aeruginosa

(DBA/N[female] X CBA/2[male])F1 males have been reported to be deficient in producing antibodies against a number of antigens, including carbohydrates (I. Scher, Adv. Immunol. 35:1-71, 1982). We show that F1 male mice, in contrast to females, made less lipopolysaccharide (LPS)-specific antibodies after immunization with heat-inactivated Pseudomonas aeruginosa and had significantly less naturally occurring LPS-specific antibodies. Furthermore, neutropenic males were 50 to 1,000 times more sensitive to challenge with representative isolates belonging to the seven Fisher immunotypes. Administration to neutropenic F1 males of a human monoclonal antibody specific for the O carbohydrates of P. aeruginosa immunotype 2 LPS or administration of serum from rabbits immunized with heat-inactivated P. aeruginosa immunotype 1 raised the level of resistance to bacterial challenge close to that of females. The results show that the X-linked immunodeficient mouse is an excellent model with which to test the protective efficacy of P. aeruginosa-specific monoclonal antibodies.

System for continuous monitoring of point defect concentrations during irradiations and anneals

An integrated system, cryostat, electronics, and computer used for detailed resistivity measurements during low-temperature irradiations and anneals of metals is described. The thermal response time and rate of heat removal from the specimens are optimized. The system has excellent stability for extended isothermal anneals; measurements of deviations from Mathiessen's rule are discussed to illustrate this feature. Examples are given of the use of the system to determine dense sets of thermal activation energies during anneals through state I. These determinations are made by linear heating at different rates during recombinations of close Frenkel pairs, and by abruptly and repeatedly changing the annealing temperature during the recovery of more widely separated pairs.

Epidemic gastritis with hypochlorhydria

Seventeen of 37 healthy volunteers participating in studies of acid secretion and 1 patient with Zollinger-Ellison syndrome became rapidly and profoundly hypochlorhydric. A mild illness with epigastric pain occurred in 9 subjects, usually several days before detection of hypochlorhydria. Gastric mucosal biopsy specimens taken from subjects during hypochlorhydria revealed severe fundal and antral gastritis; however, even when acid secretion was severely depressed, parietal cells were abundant and appeared normal histologically. During hypochlorhydria, gastric permeability to hydrogen, sodium, and lithium was normal in 4 subjects. Serum gastrin concentrations were usually normal, whereas serum pepsinogen concentrations were invariably elevated. Serum parietal cell antibodies were not present. Acid secretion returned to near baseline levels in 14 of 17 subjects after a mean of 126 days (range 53--235); severity of gastritis diminished concurrently in 7 of 10 subjects on whom biopsies were serially performed. An infectious etiology is suspected, although serologic studies and bacterial and conventional viral cultures of stool and gastric juice have not identified a candidate agent.

Suppression and reversal of allergic encephalomyelitis in rhesus monkeys with basic protein and peptides

We have extended earlier studies on the suppression of clinically evident experimental allergic encephalomyelitis (EAE) in monkeys, repeated injections of human basis protein. The results confirm that after suppressive treatment, recovered animals remain clinically normal and do not show spontaneous recurrence of symptoms. However, recovered animals are susceptible to EAE upon renewed challenge, and they develop the disease more rapidly and more severely than after the initial challenge; resuppression is also accomplished in these cases by the same methods used previously. The results indicate further that the basic protein or peptide T administered without mycobacteria is effective in suppressing the development of basic protein-induced EAE regardless of the species from which it was derived.

Experimental allergic aspermatogenic orchitis. IV. Chemical properties of sperm glycoproteins isolated from guinea pig testes

Of four glycoproteins isolated from guinea pig testes, two were aspermatogenic (types I and IV) and two (types II and III) were inactive. The glycoproteins were rich in carbohydrate, varying from 41.5% to 49.5% carbohydrate by weight. Each glycoprotein had a unique amino acid composition, but in general low levels of tyrosine, tryptophan, and basic amino acids were found along with relatively high contents of serine, threonine, glutamic acid, and proline. Types I and IV glycoproteins were remarkably stable; their aspermatogenic activity was not affected by urea, trypsin, or heating at 100 degrees C in water or in 1 M HCl for 15 min. Carbohydrate analysis revealed little difference in the monosaccharide compositions of types I and IV glycoproteins, except that only the type I contained sialic acid. In contrast, types II and III glycoproteins lacked sialicacid and fucose and contained much less mannose. Both N-acetylglucosamine and N-acetylgalactosamine were present in all four glycoproteins, and they dominated in the types II and III. Fucose and at least 20-25% of the galactose appeared to occupy terminal positions in type IV glycoprotein as shown by their release after 15 min hydrolysis in 1 M HCl. All of the glycoproteins contained a relatively high percentage of galactose by weight, from 12.6 to 19.3%. The molecular weights of the glycoproteins were estimated by sodium dodecyl sulfate gel electrophoresis to be 47000, 105000 and 18000 respectively for the types I, II, and IV; type III glycoprotein showed two major bands, with molecular weights of 41500 and 22800. All the above molecular weight values are probably overestimated because of high carbohydrate content. The molecular weight of type IV glycoprotein was found to be 13000 by ultracentrifugation; a corrected value of 29000 was calculated for type I glycoprotein.

Experimental allergic aspermatogenic orchitis. II. Some chemical properties of the AP1 protein of the sperm acrosome

The AP1 protein, a unique aspermatogenic protein localized in the sperm acrosome, exists as a single polypeptide chain of 136 amino acids, as shown by a single band on gel electrophoresis in sodium dodecyl sulfate and the recovery of the expected 21 to 22 tryptic peptides on peptide mapping. The AP1 protein appears to exist in a compact, highly stable conformation, as shown by its resistance to trypsin hydrolysis. Its aspermatogenic acitivity is not affected by trypsin treatment, by heating at 99 degrees C for 1 h, by 8 M urea, or by acid conditions. After reduction and alkylation, however, the molecule appears to open up, since it becomes hydrolyzable by trypsin and migrates more slowly on gel electrophoresis at pH 2.7 and 8.6. After alkylation, the AP1 protein still migrates as a single band at pH 2.7. The AP1 protein shows microheterogeneity near its isolectric point at pH 8.6; each of five bands shows the same amino acid analysis. Aggregation was not observed following treatment with dimethylsuberimidate. The molecular weight of 15 000, obtained from gel electrophoresis consists of 136 amino acids with a relatively high content of proline, half cystine, glycine, histidine and tryptophan. No galactose, mannose, fucose, glucose, or hexosamines were found; the AP1 protein is thus not a glycoprotein.

Experimental allergic orchitis and aspermatogenesis. VI. Transfer of allergic orchitis with immune cells

Typical experimental allergic orchitis (EAO) and aspermatogenesis were successfully transferred to strain 13 guinea pigs with peritoneal exudate and lymph node cells from male and female donor guinea pigs (lacking detectable antibody) previously sensitized with 9 mug of highly purified GP1 glucoprotein isolated from the sperm acrosome. Attempts to transfer the disease with circulating antibody from hyperimmunized animals were not successful. These studies support a cell-mediated basis for the immunopathologic events in EAO.

Experimental allergic aspermatogenic orchitis. III. Isolation of spermatozoal glycoproteins and their role in allergic aspermatogenic orchitis

Four glycoproteins (GP1,2,3 and 4) rich in carbohydrate were isolated from guinea pig testes. GP1, 2, and 4 (one or more) were localized in the sperm acrosome by the indirect immunofluorescence technique. Purification consisted of delipidation with chloroform-methanol (2:1), acid extraction at pH 3.0, precipitation with 85% saturated ammonium sulfate, extraction with 5% trichloroacetic acid, and either gel filtration on agarose or ultrafiltration. The final purification steps were isoelectrofocusing or gel filtration on Sephadex G-75 followed by preparative slab gel electrophoresis at pH 8.6. Each glycoprotein appeared homogeneous by gel electrophoresis at pH 2.7 and 8.6, and by immunoelectrophoresis. The crude glycoprotein fraction from the agarose column was resolved into the three major components, GP1, 2, and 3, distinguished by their isoelectric points (pI 3.9, 4.4, and 5.0, respectively), electrophoretic mobilities at pH 8.6, and reactivities with antiserum in immunoelectrophoresis. GP4, isolated by ultrafiltration and Sephadex G-75 chromatography, was differentiated by the same criteria. Approximately 5 mg each of purified GP1, 3, and 4 and 2 to 3 mg of GP2 were isolated from 1000 g of wet guinea pig testes. GP1, 2, and 4 induced precipitating antibody in rabbits and goats. GP1 and GP4 induced allergic aspermatogenic orchitis in guinea pigs, an autoimmune disease characterized by infiltration of mononuclear cells around and within the seminiferous tubules, followed by extensive destruction of the germinal epithelium. The course of the disease induced by 2 mug of either GP1 or GP4 was essentially identical in time course and pathology to that induced by whole testicular homogenates or 1 mug of purified acrosomal protein (AP1).

Experimental allergic aspermatogenic orchitis. 1. Isolation of a spermatozoal protein (AP1) which induces allergic aspermatogenic orchitis

A unique highly soluble aspermatogenic protein (AP1) was isolated from guinea pig testes and was shown by immunofluorescence to occupy the outer surface of the sperm acrosome. This protein is a potent inducer of allergic orchitis and aspermatogenesis; as little as 0.2 mug induced orchitis in 60 percent of guinea pig tested. The AP1 protein, relatively small and neutral, is stable under acid conditions, but at pH 8.6 shows a variety of forms due either to aggregation or polymorphism. The purified AP1 protein appeared homogeneous by polyacrylamide gel electrophoresis at pH 2.7 and in sodium dodecyl sulfate and by immunoelectrophoresis using rabbit antisera to either the purified protein or the testes extract. It also showed a single band on immunodiffusion over a wide concentration range. The purification procedure consisted of delipidation with chloroform/methanol (2/1); acid extraction at pH 3.0; precipitation with 85 percent saturated ammonium sulfate; trichloroacetic acid extraction and gel filtration on Bio-Gel A-1.5; gel filtration on Bio-Gel P-10; chromatography on CM52 cellulose; and preparative gel electrophoresis at pH 2.7. Approximately 20 mg of purified AP1 protein were obtained from 5000 g of wet guinea pig testes. The AP1 protein induced an autoimmune disease characterized by infiltration of mononuclear cells around and within the seminiferous tubules (orchitis), followed by extensive damage and destruction of the germinal cells (aspermatogenesis). The course of the disease induced by this protein (0.5 to 1 mug) was essentially identical with that seen with whole testicular tissue or other purified fractions.