Predictors of residual mass histologyafter chemotherapy for advanced testis cancer

The records of 15 patients with Stage B3 or B2/C germ cell testis tumors who underwent full surgical debulking of a residual mass after completion of chemotherapy were reviewed retrospectively to look for predictors of residual mass histology. The density, character, and change in volume of the retroperitoneal mass on computerized tomography before and after chemotherapy were compared with the histology in the primary tumor and in the residual mass. One of 6 patients without teratoma in the primary tumor had a 97 percent reduction in the mass which contained residual teratoma. Two patients with residual seminoma had a 50 percent decrease in tumor volume, and both patients died of tumor progression despite salvage chemotherapy. Two patients with pure seminomas had only residual fibrosis in masses that decreased in volume by 77 and 75 percent, respectively. One of these masses was discrete and the other was diffuse. Seven of 9 patients (78%) with teratoma in the primary tumor had either teratoma (4 of 9, 44%) or carcinoma (3 of 9, 33%) in the residual mass, and the change in mass volume ranged from a 93 percent decrease to a 540 percent increase in size. All 7 patients with residual teratoma and/or carcinoma remain free of disease after observation or further chemotherapy. For the entire series, the mass density and character did not correlate consistently with the primary tumor or residual mass histology. Residual fibrosis alone or teratoma and/or carcinoma were seen with least (0 to 50%) and greatest (more than 90%) decreases in mass volume.     

DNA vaccination of mice against rabies virus: effects of the route of vaccination and the adjuvant monophosphoryl lipid A (MPL)

Adjuvants are known to strongly enhance immune responses generated by traditional vaccines, but less is known about the effects of adjuvants on vaccination with DNA. In this study, we investigated the use of the immunostimulant monophosphoryl lipid A (MPL(R)) as an adjuvant, and analyzed three routes of DNA vaccination to determine if this adjuvant could enhance anti-rabies virus neutralizing antibody responses. Compared with antibody titers elicited with DNA only, antibody titers were enhanced after initial intradermal (i.d.) and gene gun immunizations with the combination of DNA and MPL(R). Antibody was not detected after primary intramuscular (i.m.) immunization unless MPL(R) was included with the DNA. Surprisingly, antibody titers of MPL(R)-treated mice decreased after i.d. or i.m. booster vaccinations, but increased after gene gun booster vaccinations. In contrast to these varied responses, booster immunizations without MPL(R) via the three different routes consistently increased antibody titers. All mice with detectable levels of neutralizing antibody at the time of challenge survived virus infection. There was no difference in the survival rate between groups of mice that received similar vaccinations with MPL(R)/DNA or DNA only. The data suggest that MPL(R) can enhance the neutralizing antibody response when used with the initial injection of DNA. Suppression of neutralizing antibody responses after i.d. or i.m. booster vaccinations that included MPL(R) suggests that the number of vaccinations, and the route of vaccination, should be carefully considered when MPL(R) is used with DNA vaccines.     

Post-exposure DNA vaccination protects mice against rabies virus

Post-exposure anti-rabies vaccination for individuals who have not previously been immunized against rabies includes a cell culture-derived vaccine and a one time injection of rabies immune globulin. Recent studies have shown DNA vaccinations to be highly effective in rabies pre-exposure experiments, but post-exposure protection has not been achieved. This failure is likely due to the slow onset of DNA vaccine induced antibody production. In an attempt to accelerate the onset of the antibody response, we manipulated variables, such as the route of vaccination and booster frequency. Anti-rabies virus antibody was detected 5 days after the initial DNA vaccination. Using this vaccination protocol and a single non-protective dose of anti-rabies immune serum, we questioned whether mice injected 6 h previously with rabies virus would be protected if a DNA vaccine was substituted for the cell culture-derived human diploid cell vaccine (HDCV). The DNA vaccine protected 87% of the mice (P = 0.00005, compared with unvaccinated control mice). Some 75% of mice receiving HDCV were protected (P = 0.00097, compared with unvaccinated control mice). Mice receiving only anti-rabies immune serum were not protected (P > 0.05 compared to unvaccinated control mice). Thus, post-exposure therapy, substituting a DNA vaccine for HDCV, did not compromise protection against rabies virus.     

Effects of pregnancy on muscarinic receptor density and function in the rabbit urinary bladder.

The contractile response of the rabbit urinary bladder to field stimulation consists of both cholinergic and purinergic components. In general, approximately 60% of the contractile response to field stimulation is cholinergic and 40% is purinergic. Although the purinergic response represents a significant proportion of the initial (phasic) pressure response to field stimulation of the isolated whole bladder, it contributes only 10-15% of the ability of field stimulation to empty the bladder. The current study investigates the effects of pregnancy on the contractile responses of the isolated urinary bladder to cholinergic and purinergic stimulation. The results of these studies indicate that pregnancy induces substantial changes in the physiology and pharmacology of the urinary bladder. The following data are consistent with the theory that pregnancy substantially increases the relative purinergic component of the response to field stimulation (and presumably neuronal stimulation): (1) there was a significantly greater response of the bladders isolated from pregnant rabbits to low-frequency field stimulation; (2) atropine was more effective at inhibiting the pressure generation of bladders isolated from virgin female rabbits; (3) field stimulation was more effective at emptying bladders isolated from virgin female rabbits; (4) the response of the bladders from pregnant rabbits to bethanechol was significantly reduced, whereas the response to ATP was significantly increased. In addition to these effects of pregnancy on bladder physiology, pregnancy induced a 50% decrease in the muscarinic receptor density of the urinary bladder body, which correlated very well with the 50% decrease in the contractile response to bethanechol.     

A fragment of human TrpRS as a potent antagonist of ocular angiogenesis

Pathological angiogenesis contributes directly to profound loss of vision associated with many diseases of the eye. Recent work suggests that human tyrosyl- and tryptophanyl-tRNA synthetases (TrpRS) link protein synthesis to signal transduction pathways including angiogenesis. In this study, we show that a recombinant form of a COOH-terminal fragment of TrpRS is a potent antagonist of vascular endothelial growth factor-induced angiogenesis in a mouse model and of naturally occurring retinal angiogenesis in the neonatal mouse. The angiostatic activity is dose-dependent in both systems. The recombinant fragment is similar in size to one generated naturally by alternative splicing and can be produced by proteolysis of the full-length protein. In contrast, the full-length protein is inactive as an antagonist of angiogenesis. These results suggest that fragments of TrpRS, as naturally occurring and potentially nonimmunogenic anti-angiogenics, can be used for the treatment of neovascular eye diseases.     

Induction of enhanced resistance against encephalomyocarditis virus infection of mice by nonviable Mycobacterium tuberculosis: mechanisms of protection.

Nonviable Mycobacterium tuberculosis strain Jamaica suspended in oil-droplet emulsions was used to enhance resistance of mice against encephalomyocarditis virus (EMCV). The mycobacteria-injected mice were significantly resistant to 50,000 50% lethal doses of EMCV. Similar concentrations of virus in plasma of normal and mycobacteria-injected mice from 1 to 120 min after injection of EMCV showed that resistance was not a result of rapid elimination of virus from the circulation. Furthermore, survival of viremic mice indicated protective mechanisms were operative after EMCV had escaped primary surveillance. Resistance did not appear to be associated with the mouse major histocompatibility gene complex. The spleen was intimately associated with protection, and the thymus was nonessential for enhanced resistance to EMCV. Protection was significantly diminished by cyclophosphamide injected intraperitoneally from 3 days before to the day of virus challenge. Finally, silica given intraperitoneally 24 h before virus completely abrogated resistance of mycobacteria-injected mice to EMCV. These results suggest that macrophages functioning independently of T-lymphocytes are important effector cells in resistance to EMCV of mice injected with nonviable mycobacteria.     

Modulation of dietary fat-promoted pancreatic carcinogenesis in rats and hamsters by chronic ethanol ingestion

The effect of chronic ethanol ingestion on dietary fat-promotedpancreatic carcinogenesis was investigated in rats and hamsters.Rats were given a single i.p. injection of 30 mg azaserine perkg body wt at 19 days of age. Hamsters were injected s.c. with20 mg N-nitrosobis(2-oxopropyI)amine (BOP) per kg body wt at6 and 7 weeks of age. The animals were fed a semi-purified diethigh in unsaturated fat (25% corn oil) either separately orin combination with ethanol. Ethanol was provided in drinkingwater at a concentration of 10% (w/v). A separate group maintainedon a diet low in unsaturated fat (5% corn oil) was includedas extra controls. The rats and hamsters were given their dietsand received ethanol via their drinking water after treatmentwith carcinogen. Terminal autopsy of rats was 15 months afterazaserine treatment and of hamsters 12 months after the lastinjection with BOP. Dietary fat was found to enhance pancreaticcarcinogenesis in both rats and hamsters. In rats, ethanol slightlyenhanced the multiplicity but not the incidence of malignanttumours, while in hamsters ethanol did not show any modulatingeffect on dietary fat-promoted carcinogenesis. It was concludedthat dietary fat-promoted pancreatic carcinogenesis as observedin the animal models applied is not significantly modulatedby chronic ethanol ingestion.     

Buccal Mucosal Urethral Replacement

Graft substances, such as skin and bladder mucosa, have been previously used for urethral replacement when local epithelial tissue was not available. However, these substances have been associated with meatal prolapse, stricture and fistula formation. We have used buccal mucosa as a tissue for urethral substitution in these situations during the last 8 years. We review our clinical experience in 18 urethral reconstructions performed for urethral replacement in 4 cases of exstrophy/epispadias, 12 complex hypospadias repairs and 2 cases of complex bulbar urethral strictures. There have been 5 cases of meatal stenosis (2 requiring operative revision) but none of meatal eversion. There has also been 1 urethrocutaneous fistula and 1 mid graft stricture. Mean followup was 27 months and minimum followup was 6 months.Histological examination of the buccal mucosal graft compared to grafts of skin showed that the full thickness of the dermis or lamina propria is thinnest while the native vascular supply is greatest in the buccal mucosa. These 2 factors are associated with improved graft take and may explain the encouraging clinical results.     

Determination of stability of Brucella abortus RB51 by use of genomic fingerprint, oxidative metabolism, and colonial morphology and differentiation of strain RB51 from B. abortus isolates from bison and elk.

Brucella abortus RB51 and isolates from cattle, bison, and elk were characterized by pulsed-field gel electrophoresis and standard techniques for biotyping Brucella species, which included biochemical, morphological, and antigenic techniques, phage susceptibility, and antibiotic resistance. The objectives were to ascertain the stability of RB51 and to differentiate RB51 from other brucellae. Genomic restriction endonuclease patterns produced by pulsed-field gel electrophoresis demonstrated a unique fingerprint for RB51 relative to other brucellae. Comparisons of the oxidative metabolic profiles of RB51 after time in vivo (14 weeks) and in vitro (75 passages) showed no change in characteristic patterns of oxygen uptake on selected amino acid and carbohydrate substrates. Strain RB51 was biotyped as a typical rough B. abortus biovar 1 (not strain 19) after animal passage or a high number of passages in vitro and remained resistant to rifampin or penicillin and susceptible to tetracycline. No reactions with A or M antiserum or with a monoclonal antibody to the O antigen of Brucella lipopolysaccharides were detected; however, RB51 agglutinated with R antiserum. The results indicate that the genomic fingerprint and rough colonial morphology of RB51 are stable characteristics and can be used to differentiate this vaccine strain from Brucella isolates from cattle, bison, and elk.