[Clinical evaluation of nitrite test for the detection of bacteriuria]

A nitrite test for bacteriuria was compared with routine microscopic examination in 1,318 clinical urine specimens and with bacterial culture in 132. Sensitivity, specificity, positive predictive value and accuracy rate are as follows; for diagnosis of bacteriuria more than 10(4) CFU/ml, 53.4%, 88.6%, 90.4 and 65.2%, respectively; for more than 10(5) CFU/ml, 55.4%, 87.8%, 88.4% and 67.2%, respectively. The positive rate for the nitrite test was 21.4% for bacteriuria of > or = 10(4) CFU/ml in gram positive cocci and 56.9% in gram negative rods. False negative results were obtained from gram positive cocci without nitrate reductive activity or from patients with acute uncomplicated cystitis because of insufficient incubation time in urinary tract. However, this simple test is valuable in the detection of bacteriuria in clinical practice with high specificity.

Progesterone receptor repression by estrogens in rat uterine epithelial cells

Measurements performed using cell lines or animal tissues have shown that the progesterone receptor (PR) can be induced by estrogens. By use of immunohistochemistry we studied the effects of estrogens on the PR levels in the individual cell types of the target organs uterus and breast. In the uteri of rats, ovariectomy induced a decrease in PR immunoreactivity within the myometrium and outer stromal cell layers. In contrast, in the uterine luminal and glandular epithelium and surrounding stromal cell layers the PR immunoreactivity was significantly enhanced. The same picture emerged when intact rats were treated with the pure estrogen receptor antagonist, ZM 182780 (10 mg/kg/d). Treatment of ovariectomized rats with estradiol resulted in high PR levels in the myometrium and stroma cells but low PR immunoreactivity in the epithelial cells. The ER-mediated repression of the PR immunoreactivity was evidently restricted to the uterine epithelium, as we found that in the epithelial cells of the mammary gland and in cells of N-nitrosomethylurea-induced mammary carcinomas the PR expression was induced by estrogens and was blocked by the pure antiestrogen ZM 182780. These results clearly show that in the rat the activated ER induces diverging effects on PR expression in different cell types even within the same organ.

Improved antimicrobial activity of DU-6859a, a new fluoroquinolone, against quinolone-resistant Klebsiella pneumoniae and Enterobacter cloacae isolates with alterations in GyrA and ParC proteins

MICs of DU-6859a, a novel fluoroquinolone, for 18 Klebsiella pneumoniae isolates and 21 Enterobacter cloacae isolates with altered GyrA or altered GyrA and ParC ranged from < or =0.025 to 6.25 microg/ml and from 0.1 to 3.13 microg/ml, respectively. Based on the MICs at which 90% of the isolates were inhibited for these strains of K. pneumoniae and E. cloacae, DU-6859a exhibited 16- to 256-fold-greater activity than currently available fluoroquinolones.

Detection of mutations in the gyrA and parC genes in quinolone-resistant clinical isolates of Enterobacter cloacae

We have determined partial sequences of the gyrA and parC genes of Enterobacter cloacae type strain including the regions analogous to the quinolone resistance-determining region of the Escherichia coli gyrA gene. The deduced 65- and 49-amino acid sequences of the determined regions of the E. cloacae gyrA and parC genes were identical to the corresponding regions of the E. coli GyrA and ParC proteins, respectively. We examined 40 clinical strains of E. cloacae isolated from patients with urinary tract infection for susceptibilities to nalidixic acid and ciprofloxacin. Based on the nalidixic acid and ciprofloxacin MICs, these isolates were divided into 19 quinolone-susceptible strains (MICs of nalidixic acid, 3.13-25 mg/L; MICs of ciprofloxacin, < or = 0.025 mg/L) and 21 quinolone-resistant strains (MICs of nalidixic acid, 400 to > 800 mg/L; MICs of ciprofloxacin, 0.39-100 mg/L). We analysed five quinolone-susceptible and 21 quinolone-resistant strains for alterations in GyrA and ParC. The five quinolone-susceptible strains had amino acid sequences in GyrA and ParC identical to those of type strain. Of the 21 quinolone-resistant isolates, three (MICs of nalidixic acid, 400 to > 800 mg/L; MICs of ciprofloxacin, 0.39-3.13 mg/L) had a single amino acid change at the position equivalent to Ser-83 in the E. coli GyrA protein and no alterations in ParC; one (MIC of nalidixic acid, > 800 mg/L; MIC of ciprofloxacin, 3.13 mg/L) had a single amino acid change at Ser-83 in GyrA and a single amino acid change at the position equivalent to Glu-84 in the E. coli ParC protein; two (MIC of nalidixic acid, > 800 mg/L; MIC of ciprofloxacin, 25 mg/L) had double amino acid changes at Ser-83 and Asp-87 in GyrA and no alterations in ParC; and 15 (MICs of nalidixic acid, > 800 mg/L; MICs of ciprofloxacin, 25-100 mg/L) had double amino acid changes at Ser-83 and Asp-87 in GyrA and a single amino acid change at Ser-80 or Glu-84 in ParC. This study suggests, that in clinical isolates of E. cloacae, DNA gyrase is a primary target of quinolones, that only a single amino acid change at Ser-83 in GyrA is sufficient to generate high-level resistance to nalidixic acid and to decrease susceptibility to ciprofloxacin, and that the accumulation of amino acid changes in GyrA and the simultaneous presence of the ParC alterations play a central role in developing high-level resistance to ciprofloxacin.

Mutations in the gyrA and parC genes associated with fluoroquinolone resistance in clinical isolates of Citrobacter freundii

We determined partial sequences of the gyrA and parC genes of Citrobacter freundii type strain, and then examined 38 C. freundii clinical strains isolated from patients with urinary tract infections for the association of alterations in GyrA and ParC with susceptibility to fluoroquinolones. Our results suggest that in C. freundii DNA gyrase may be a primary target of quinolones, that an amino acid change at Thr-83 or Asp-87 in GyrA is sufficient to decrease susceptibility to fluoroquinolones, and that accumulation of changes in GyrA with the simultaneous presence of an alteration at Ser-80 or Glu-84 in ParC may be associated with the development of high-level fluoroquinolone resistance in C. freundii clinical isolates.

Effects of misclassification and temporal change of response in food frequency on risk ratio

Misclassification and temporal changes of food consumption frequencies were estimated under the statistical models with some assumptions, and their effects on risk ratios were evaluated. Food frequencies of 27 items in 214 subjects were doubly measured by a questionnaire with 2 weeks interval, and those in 326 subjects were measured in 1989, 1993 and 1994. Median of probabilities of misclassification in responses among 27 food items was estimated to be 0.12. Medians of proportions of persons whose responses in 1989 were different from those after 5 years, were calculated to be 35% with misclassification and 27% without misclassification. For the true risk ratio of 3, medians of the risk ratios of dietary habits during 5 years, based on food frequencies measured at 1989, were observed to be 2.2 in case of responses with misclassification, and 1.7 in case of responses with misclassification and temporal changes. These suggested that the risk ratios of food frequencies would be seriously affected by misclassification and temporal changes in responses.

Development of a rapid assay for detecting gyrA mutations in Escherichia coli and determination of incidence of gyrA mutations in clinical strains isolated from patients with complicated urinary tract infections

The MICs of ofloxacin for 743 strains of Escherichia coli isolated from 1988 to 1994 were determined by testing. The strains were from patients with urinary tract infections complicated by functional or anatomical disorders of the urinary tract. Those determined to be ofloxacin resistant (MIC, > or =12.5 microg/ml) comprised 3 of 395 strains (1.3%) from the 1988 to 1990 group, 2 of 166 strains (1.2%) from the 1991 to 1992 group, and 7 of 182 strains (3.8%) from the 1993 to 1994 group. The incidence of resistant strains increased significantly during this period. The percentage of isolates with moderately decreased susceptibilities to ofloxacin (MIC, 0.39 to 3.13 microg/ml) also rose during the same period. To determine the incidence of gyrA mutations in urinary-tract-derived strains of E. coli, we developed a simple and rapid assay based on PCR amplification of the region of the gyrA gene containing the mutation sites followed by digestion of the PCR product with a restriction enzyme. Using this assay, we examined all 182 strains isolated in 1993 and 1994 for the presence of mutations at Ser-83 and Asp-87 in the gyrA gene. Of these strains, 33 (18.1%) had mutations in the gyrA gene. The incidences of mutations at Ser-83, at Asp-87, and at both codons were 10.4 (19 strains), 4.4 (8 strains), and 3.3% (6 strains), respectively. To determine the correlation of the mutations in the gyrA gene with susceptibilities to quinolones (nalidixic acid, ofloxacin, norfloxacin, and ciprofloxacin), we further examined 116 strains for which the MICs of ofloxacin were > or =0.2 microg/ml that were chosen from the isolates in the 1988 to 1992 group. The MICs of nalidixic acid for the strains without mutations at either Ser-83 or Asp-87 were < or =25 microg/ml, whereas those for the strains with single mutations or double mutations were from 50 to >800 microg/ml. For the fluoroquinolones, significant differences in the distributions of the MICs were observed among the strains without mutations, with single mutations, and with double mutations. The accumulation of mutations in the gyrA gene was associated with an increase in fluoroquinolone resistance. Ofloxacin MICs for the majority of the strains with single and double mutations were 0.39 to 3.13 and 6.25 to 100 microg/ml, respectively. This study demonstrates a chronological increase in the percentage of not only highly fluoroquinolone-resistant strains, corresponding to those with double mutations in the gyrA gene, but also strains with moderately decreased susceptibilities to fluoroquinolones, corresponding to those with single mutations. This increase in the incidence of strains with a single mutation in the gyrA gene portends a further increase in the incidence of strains with clinically significant resistance to fluoroquinolones.

Fluoroquinolone treatment failure in gonorrhea. Emergence of a Neisseria gonorrhoeae strain with enhanced resistance to fluoroquinolones

BACKGROUND AND OBJECTIVES

Although emergence of clinical isolates of Neisseria gonorrhoeae with decreased susceptibilities to fluoroquinolones and treatment failures in gonorrhea have been reported, there have been no clinical reports that fluoroquinolone treatments actually select quinolone-resistant strains, nor have isolates that exhibited clinically significant resistance been analyzed for resistance mechanisms.

GOALS

To report a case of fluoroquinolone treatment failure in gonorrhea and emergence of a posttreatment isolate with enhanced resistance to fluoroquinolones; and to study mechanisms of quinolone resistance in the isolates from this patient.

STUDY DESIGN

A patient with gonococcal urethritis treated with ofloxacin, 200 mg, three times daily for 5 days is described. Pretreatment and posttreatment isolates were tested for minimum inhibitory concentrations (MICs) of antimicrobial agents and analyzed for alterations in DNA gyrase and topoisomerase IV. They were also examined for ofloxacin uptake.

RESULTS

Treatment failure with multiple doses of ofloxacin was observed in this case of gonorrhea. The pretreatment isolate showed decreased susceptibilities to fluoroquinolones (MIC of ofloxacin, 1.0 mg/l; MIC of ciprofloxacin, 0.25 mg/l), and had amino acid changes of Ser-91-->Phe in GyrA and Ser-87-->Ile in ParC. The posttreatment isolate exhibited an increase in resistance to fluoroquinolones (MIC of ofloxacin, 8.0 mg/l; MIC of ciprofloxacin, 1.0 mg/l). This isolate had identical alterations in GyrA and ParC, but exhibited significantly reduced uptake of ofloxacin. This isolate also showed a small decrease in susceptibilities to cephalosporins.

CONCLUSIONS

Alterations in DNA gyrase and topoisomerase IV confer clinically significant resistance to fluoroquinolones in N. gonorrhoeae strains. Treatment with multiple doses of fluoroquinolones is likely to bring about selection of more fluoroquinolone-resistant strains of N. gonorrhoeae and to influence susceptibilities to cephalosporins.

The antiovulatory effect of the antiprogestin onapristone could be related to down-regulation of intraovarian progesterone (receptors)

The present study was undertaken to investigate intraovarian mechanism(s) for the antiovulatory effect of Onapristone (ON), because antiprogestins possessing the same antiprogestational activity and inhibiting the preovulatory LH surge to the same extent differ in their antiovulatory potency. Ovulation was induced by treating immature female rats with pregnant mare serum gonadotropin (PMSG) for folliculogenesis and hCG for the induction of ovulation. The animals were treated twice with ON (200 mg/kg 42 h and 48 h after PMSG) and killed at different times. The ovulation rate was assessed by counting the number of ova in the fallopian tubes and uteri. Blood and ovaries were collected for radioimmunoassay (RIA) of steroid hormones and histological analysis for 3beta-hydroxysteroid dehydrogenase (3beta-HSDH), 17beta-hydroxysteroid dehydrogenase (17beta-HSDH), progesterone (PR), estrogen (ER) and androgen (AR) receptors. Treatment with ON totally blocked ovulation and the progesterone (P4) surge was significantly diminished in comparison to the control (6-8 h post-hCG), whereas androgen levels remained unaffected. The decreased P4 concentrations correlated well with a reduced staining intensity of 3beta-HSDH in granulosa cells of tertiary follicles. Moreover, we observed a down-regulation of PR in granulosa cells of tertiary follicles. Additionally, in secondary and tertiary follicles the expression of AR between 0 and 6 h after hCG was reduced. These results suggest that the antiovulatory effect of the antiprogestin ON is related to down-regulation of intraovarian progesterone, caused by attenuated 3beta-HSDH activity and PR expression. One can thus assume that intraovarian P4 is an important factor for the induction of ovulation. An effect of ON on the staining intensity of 17beta-HSDH in theca and granulosa cells could not be observed at any time. In conclusion, the inhibition of ovulation induced by the antiprogestin, ON, could be related to decreased intraovarian progesterone production through reduced 3beta-HSDH activity and the down-regulation of PR.

Single Thai women's interpersonal communication and mass media reception on AIDS

This research examines young unmarried women's ways of talking about AIDS, AIDS prevention, and its relationship to mass media AIDS messages in Thailand. Data were derived from a survey conducted in four districts of Kanchanaburi province. Three hundred ninety-seven unmarried women were extracted from the approximately 1,800 original subjects for this analysis. Respondents were asked about the subjects and extent of their conversations about AIDS, the choice of discussion partners, considerations of social appropriateness in talking about the disease, as well as their risk perception. Important findings were that (a) women tend to talk about AIDS primarily with friends and siblings, (b) their reception level of mass media messages is related to the number of topics discussed and frequency of talks by the subjects, and (c) socioeconomic status and age are related to the variety and frequency of talking about AIDS. Implications for AIDS education are discussed.

Esophageal metastasis from prostate cancer: diagnostic use of reverse transcriptase-polymerase chain reaction for prostate-specific antigen

An extremely rare case of esophageal metastasis from prostate cancer is reported. A 65-year-old man presented with anorexia and back pain. Upper gastrointestinal X-ray fluoroscopy and endoscopy revealed a shallow longitudinal ulcer, with converging mucosal folds, approximately 5 cm above the esophagogastric junction. The histological diagnosis of the biopsied specimen was adenocarcinoma. Blood biochemistry revealed elevated serum prostate-specific antigen (PSA) and gamma-seminoprotein levels. Ultrasonography of the prostate disclosed a hypoechoic lesion in the left lobe, and needle biopsy led to the diagnosis of prostatic adenocarcinoma. Since there was no finding suggestive of a primary lesion, apart from that in the prostate, we conducted reverse transcriptase-polymerase chain reaction (RT-PCR) for PSA. PSA-positive mRNA was demonstrated in the tissue of the esophageal tumor. There are three reports on metastasis to the esophagus from prostate cancer, but this is the first case of esophageal metastasis from prostate cancer without any evidence of metastasis to other organs. The importance of RT-PCR for the diagnosis of primary lesions of metastatic cancer is discussed.

The role of tumor-associated antigen in bovine leukemia virus-induced lymphosarcoma

Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis (EBL), which is the most common neoplastic disease of cattle. To clarify the way in which BLV-infected cattle progress from the asymptomatic stage to the lymphoma stage, we produced a monoclonal antibody (MAb) c143 which recognized a tumor-associated antigen (TAA) that is phosphorylated in the transformed state of BLV-infected B-lymphoid cells. Since the nature of c143 TAA was likely to be that of the major histocompatibility complex (MHC) class II antigens, we isolated cDNAs for bovine MHC (BoLA) class II a-chains and b-chains, produced transfectants that expressed a single type of BoLA class II molecules and analyzed them by flow cytometry with c143 MAb. The c143 MAb recognized the transfectant expressing BoLA-DR but not BoLA-DQ. However, the treatment of lymphocytes with c143 or anti-BoLA-DR MAb induced different effects. Although mixed lymphocyte reaction (MLR) was inhibited by the addition of anti-BoLA-DR MAb, the c143 MAb did not inhibit a proliferative response of T cells in MLR. Increased spontaneous proliferation of lymphocytes in healthy donors was obtained in the presence of c143 MAb but not anti-BoLA-DR MAb, and was much in lymphocytes from the carrier. Moreover, the patterns of immunohistological staining for c143 MAb in BLV-infected sheep showed distinguishing differences from those of anti-BoLA-DR MAbs.

Rapid screening of point mutations of the Neisseria gonorrhoeae parC gene associated with resistance to quinolones

To detect quinolone resistance-associated mutations within the Asp-86, Ser-87, Ser-88, and Glu-91 codons of the Neisseria gonorrhoeae parC gene, we developed a rapid and simple assay based on amplification of the regions of the parC gene containing the mutations sites by PCR and digestion of the PCR products with restriction enzymes. By using the method of primer-specified restriction site modification, artificial SalI, PstI, EcoRI, and HinfI restriction sites were created in the regions containing the Asp-86, Ser-87, Ser-88, and Glu-91 codons, respectively. The mutations generating alterations at Asp-86, Ser-87, Ser-88, and Glu-91 were detected as failures of SalI, PstI, EcoRI, and HinfI to digest the respective PCR products. Fifty-five clinical strains of N. gonorrhoeae were examined for mutations in the parC gene by this assay. Appropriate mutations at either the Asp-86, Ser-87, Ser-88, or Glu-91 codon were detected in each of 11 strains in which a mutation had previously been observed by DNA sequencing. This rapid and simple assay could be a useful device for screening genetic alterations in the parC gene associated with resistance to quinolones in N. gonorrhoeae.

Human immunodeficiency virus type 1 Vpr gene product prevents cell proliferation on mouse NIH3T3 cells without the G2 arrest of the cell cycle

Human immunodeficiency virus type 1 Vpr is a 96-amino-acid virion-associated protein that arrests cells in the G2 phase of the cell cycle in peripheral blood lymphocytes, HeLa, 293, 293T, A549, Jurkat, CEM, SupT1, CV-1 and COS1 cells. When we transfected Vpr expression vector into mouse NIH3T3 and then cultured it in the presence of G418, NIH3T3 cells were the drug resistant cells yielded. The surviving colonies, however, exhibited a degenerating morphology up to 8 approximately 20-fold smaller than the control vector colonies. In addition, the growth of NIH3T3 cells transiently transfected with Vpr expression vector declined dramatically compared with that of transfectants with control vector, suggesting that Vpr significantly interferes with cell proliferation of NIH3T3 cells. Cell cycle characterization by flow cytometry indicated that expression of Vpr did not induce G2 cessation in NIH3T3. These findings strongly suggest that Vpr has a novel pathway to retard cell growth independently and arrests the G2 phase of the cell cycle.

Alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in quinolone-resistant clinical isolates of Klebsiella pneumoniae

We determined a partial sequence of the Klebsiella pneumoniae parC gene, including the region analogous to the quinolone resistance-determining region of the Escherichia coli gyrA gene, and examined 26 clinical strains of K. pneumoniae for an association of alterations in GyrA and ParC with susceptibilities to quinolones. The study suggests that in K. pneumoniae DNA gyrase is a primary target of quinolones and that ParC alterations play a complementary role in the development of higher-level fluoroquinolone resistance.

Detection of micrometastatic prostate cancer cells in the bone marrow of patients with prostate cancer

Thirty-five patients with prostate cancer were examined for micrometastases to the bone marrow using reverse transcription-polymerase chain reaction (RT-PCR) with primers specific for the prostate-specific antigen (PSA) gene. Of nine patients with bone metastases detectable by bone scan imaging, five patients had PSA mRNA expression in the bone marrow detectable by RT-PCR. Of 26 patients with negative bone scan findings, seven patients had PSA mRNA expression detectable in the bone marrow. RT-PCR could detect micrometastatic prostate cancer cells in the bone marrow that were not detectable by bone scan imaging. Of 16 patients with a serum PSA concentration of 25 ng ml(-1) or greater, only nine (56.3%) had bone metastases detected by bone scans. Of the remaining seven patients, five had micrometastases to the bone marrow detected by RT-PCR. Overall, 14 of 16 patients (87.5%) with a serum PSA concentration of 25 ng ml(-1) or greater had metastatic bone diseases including bone marrow micrometastases. Of 19 patients with a serum PSA concentration of less than 25 ng ml(-1), two (10.5%) had only micrometastatic disease detected by RT-PCR. A significant correlation was observed between the incidence of bone involvement and the serum PSA concentration. This study suggests that RT-PCR will potentially develop into a relevant tool to assess bone involvement including bone marrow micrometastases and establish a precise correlation between serum PSA concentration and metastatic bone disease in patients with prostate cancer.

Serial passage of human immunodeficiency virus type 1 generates misalignment deletions in non-essential accessory genes

Human immunodeficiency virus type 1 (HIV-1) derived from an infectious molecular clone pNL432 was extensively passaged in tissue culture by repeated rounds of acute infection. We previously showed the natural occurrence of a nonsense mutation in the vpr gene during continued passage of this virus. In this report, we show that two forms of large deletions (561 and 518 base pairs containing short direct repeats at the deletion junctions) occur after passage 50 in the region that spans the vif and vpr open reading frames. One model to explain the occurrence of these deletion regions is that such mutations result from misalignment of the growing point at a limited number of nucleotide positions. Infection of CD4+ T-cells with a recombinant HIV-1 construct containing the same vif to vpr deletion showed virtually no cytopathogenic phenotype. Thus, misalignment deletions at non-essential accessory genes of HIV-1 might be induced during replication, which result in the generation of virus with a low cytopathogenic potential.

[Molecular approach to detection of micrometastatic prostatic cancer cells in the lymph nodes and the bone marrow]

We detected micrometastatic prostate cancer cells in lymph nodes and bone marrow using reverse transcriptase-polymerase chain reaction (RT-PCT) specific for prostate-specific antigen (PSA). RT-PCR revealed PSA mRNA in two lymph nodes obtained from two patients with negative histological and immunohistochemical analyses for lymph node metastases. Of 26 patients with negative bone scan imaging, 7 had PSA mRNA detected in the bone marrow by RT-PCR. The RT-PCR will be a relevant tool to allow a more accurate clinical assessment of lymph node and bone metastases in patients with prostate cancer.

The antiovulatory activity of progesterone antagonists is not correlated to their antiprogestational potency in the rat

Progesterone antagonists often differ in regard to their potency to block ovulation in rats although they may possess similar 'antiprogestational' (abortive) activity. Therefore, the questions arose as to: (a) whether antiovulatory and antiprogestational effects (on endometrial and mammary gland parameters) of antiprogestins correlate at all; and (b) which mechanism(s) may be responsible for their ability to abolish ovulation. To answer these questions we set out to compare the influences of two progesterone antagonists, Onapristone (ON) a very potent and ZK 136798 only a weak inhibitor of ovulation, to assess changes on the one hand on typical progestational actions and on the other hand on factors known to regulate ovulation. For this purpose immature PMSG/hCG primed and adult female rats and infantile female rabbits were treated either with ON, ZK 136798 or vehicle in different treatment schedules. In these investigations ON and ZK 136798 showed similar antiprogestational activities on the progesterone-induced development of mammary glands (rats) and the secretory transformation of endometrium (rabbits). ON blocked an induced or a spontaneous ovulation, whereas ZK 136798 only revealed a very weak antiovulatory effect. Both ON and ZK 136798 stimulated basal levels of LH, estradiol, and testosterone, whereas the preovulatory LH surge was decreased to the same extent. Interestingly, in contrast to ZK 136798, ON reduced the preovulatory increase in progesterone secretion. These results clearly indicate: (a) that antiovulatory potency and antiprogestational activity may not be correlated in the rat; and (b) that decreased preovulatory levels of progesterone following treatment with ON may play an important role in intraovarian mechanism(s) contributing to a blocking of ovulation.

A novel 1 beta-methylcarbapenem antibiotic, S-4661. Synthesis and structure-activity relationships of 2-(5-substituted pyrrolidin-3-ylthio)-1 beta-methylcarbapenems

The synthesis and biological activity of (1R,5S,6S)-2-[(3S,5S)-5-substituted pyrrolidin-3-ylthio]-6-[(1R)-1-hydroxyethyl]-1- methylcarbapen-2-em-3-carboxylic acids are described. These compounds exhibit potent antibacterial activity against a wide range of both Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa. Of these new carbapenems, (1R,5S,6S)-2-[(3S,5S)-5-sulfamoylaminomethyl pyrrolidin-3-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methylcarb apen- 2-em-3-carboxyli c acid (S-4661) showed the most potent and well balanced activity and was selected as a candidate for further evaluation.

Long-lasting immune response induced by recombinant bacillus Calmette-Guérin (BCG) secretion system

The recombinant bacillus Calmette-Guérin (rBCG) secretion system utilizing an extracellular alpha antigen of Mycobacterium kansasii (alpha-K) was characterized biochemically and immunologically. The human immunodeficiency virus type 1 (HIV-1) p17gag B cell epitope fused to alpha-K was secreted in extremely large amounts. At least three mice out of seven inoculated with rBCG generated high titres of antibody to the epitope. The long-lasting antibody production persisted more than 14 months.

Mitogenic effect of HIV-infected human T cell lines on mouse B cells mediated by surface immunoglobulin

Following HIV-1 infection, a number of disorders are induced in both normal T and B cells by virus products derived from infected CD4+ T cells. In the present study, we found that HIV-infected, but not uninfected, human T cell lines generated vigorous blastogenesis and proliferation of freshly isolated mouse B cells in a short-term culture. Neither human B cells nor rat B cells showed significant responses to the HIV-infected T cell lines in the present condition. The mitogenic effect of HIV-infected human T cell line requires direct cell-cell interaction between mouse B cells and HIV-infected T cell lines. Since either mitomycin c treatment or paraformaldehyde fixation of HIV-infected T cell lines resulted in complete loss of the mitogenic effect, it seems that de novo synthesized viral products are responsible for this effect. Furthermore, anti-mouse immunoglobulin antibody inhibited completely the B cell stimulation by the HIV-infected human T cell lines. Thus, surface immunoglobulin (sIg) on mouse B cells appears to be an essential molecule which transduces activation signals from HIV-infected human T cells into cytoplasm of the B cells.