Testosterone levels increase in association with recovery from acute fracture in men.

UNLABELLED: In this longitudinal case-control study, acute fracture was associated with low serum testosterone, which was transient in 43% of men. While assessment of gonadal status is part of the assessment of bone fragility, measurement of testosterone in the early period after fracture may overestimate the prevalence of androgen deficiency. INTRODUCTION: Measurement of circulating testosterone is recommended in the evaluation of bone fragility in men. Since acute illness can transiently decrease circulating testosterone, we quantified the association of acute fracture and serum testosterone levels. METHODS: A case-control study was conducted involving 240 men with a radiologically confirmed minimal trauma fracture presenting to a tertiary referral hospital and 89 age-matched men without a history of minimal trauma fracture serving as controls. Follow-up testosterone levels 6 months after baseline were available for 98 cases and 27 controls. Results were expressed as the median and interquartile (IQR) range. RESULTS: Compared to controls, cases had lower total testosterone [TT, 7.2 (3.5, 10.8) vs 13.6 (10.9, 17.1) nmol/L, p < 0.001]. The 143 cases treated as inpatients had lower testosterone levels than the 97 cases treated as outpatients [TT 4.7 (2.3, 8.1) vs 10.3 (7.5, 12.7) nmol/L, p < 0.001]. Group differences in calculated free testosterone (cFT) were comparable to the group differences in TT. At follow-up, in 98 cases, median TT increased from 6.5 nmol/L (3.2, 8.5) to 9.6 nmol/L (6.9, 12.0) p < 0.0001, and SHBG remained unchanged. Of cases with low testosterone, 43% with TT <10 nmol/L and/or cFT <230 pmol/L at presentation were reclassified as androgen sufficient at follow-up. TT was unchanged in the controls. CONCLUSIONS: Low testosterone levels in men presenting with an acute fracture may, at least in part, be due to an acute, fracture-associated, stress response. To avoid over diagnosis, evaluation for testosterone deficiency should be deferred until recovery from the acute event.

Antimicrobial activity of erythromycin and clarithromycin against clinical isolates of Escherichia coli, Staphylococcus aureus, Klebsiella and Proteus by disc diffusion method.

Fifty clinical isolates comprising of Escherichia coli, Staphylococcus aureus, Klebsiella and Proteus were collected from different local pathological laboratories and their resistant pattern against two well known macrolides; erythromycin and clarithromycin were studied using disc diffusion method. Klebsiella (41.67% against erythromycin and 58.34% against clarithromycin) and Proteus (66.67% against erythromycin and clarithromycin) species were found to be more resistant against the studied macrolides as compared to the rest of organisms. In case of Staphylococcus aureus and Escherichia.coli, resistant found were 27.78% and 23.54% against erythromycin and 22.23% and 35.30% against clarithromycin respectively. It is concluded from these figures that microbial resistance against these macrolides are increasing in our population which is alarming and therefore it is recommended to physicians to prescribe these antibiotics unless no other substitute is available in clinical practices.

Caught in the act: in vivo development of macrolide resistance to Campylobacter jejuni infection.

We report the first instance of macrolide resistance developing in vivo following appropriate antibiotic use in a healthy volunteer as a part of a controlled human infection with Campylobacter jejuni. In vivo development of macrolide resistance may be an important contributor to antibiotic resistance in C. jejuni.

Studies of food drug interactions.

Medicines can treat and alleviate many diseases provided that they must be taken properly to ensure that they are safe and useful. One issue related with the medicines is that whether to take on empty stomach or with food. The present work gives information regarding food-drug interactions that were studied by collecting seventy five prescriptions from various hospitals. In most of the collected prescriptions, food-drug interactions were detected using the literature available. It was also found that only few studies have been carried out so far on the effect of food on drug disposition in the Asian population. Thus more studies on food-drug interactions particularly in the local population is recommended in order to determine the effect of food and food components on drug disposition and to the kinetics of the drugs which has not yet well highlighted in this part of the world.

Transovarial transmission of murine typhus rickettsiae in Xenopsylla cheopis fleas.

It has been generally accepted that infected fleas do not pass on Rickettsia mooseri, or indeed any other known pathogen, to their progeny. It is reported here that such transovarial transmission does occur in laboratory-infected Xenopsylla cheopis fleas. By means of the direct fluorescent antibody test, Rickettsia mooseri was observed in cells of the hemolymph of infected fleas. As many as 11 percent of the adults and 2.9 percent of the larvae of the generation reared therefrom, had demonstrable rickettsiae. Moreover, batches of the F1 fleas were capable of transmitting the infection to more than 18 percent of the rats they infested. The data support the contention that Xenopsylla cheopis fleas play an important role in the maintenance of murine typhus in rats in nature.

Safety, infectivity, immunogenicity, and in vivo stability of two attenuated auxotrophic mutant strains of Salmonella typhi, 541Ty and 543Ty, as live oral vaccines in humans.

Two Salmonella typhi mutants, 541Ty (Vi+) and 543Ty (Vi-), auxotrophic for p-aminobenzoate and adenine, were evaluated as live oral vaccines. 33 volunteers ingested single doses of 10(8), 10(9), or 10(10) vaccine organisms, while four others received two 2 X 10(9) organism doses 4 d apart. No adverse reactions were observed. Vaccine was recovered from coprocultures of 29 of 37 vaccinees (78%) and from duodenal string cultures of two; repeated blood cultures were negative. The humoral antibody response to S. typhi O, H, Vi, and lysate antigens in serum and intestinal fluid was meager. In contrast, all vaccinees manifested cell-mediated immune responses. After vaccination, 69% of vaccinees overall and 89% of recipients of doses greater than or equal to 10(9) responded to S. typhi particulate or purified O polysaccharide antigens in lymphocyte replication studies but not to antigens of other Salmonella or Escherichia coli. All individuals, postvaccination, demonstrated a significant plasma-dependent mononuclear cell inhibition of wild S. typhi.

An improved model for the examination of biological effects of locally administered cytokines.

Cytokines incorporated into agarose blocks and implanted subcutaneously into mice establish an in vivo gradient which can be used to mimic a local inflammatory process. We have developed a model in which cellular influx into cytokine impregnated blocks parallels the normal cellular reaction to infections or wounds. Agarose blocks containing supernatants from ConA activated rat spleen cells attracted neutrophils within 4 h. These cells were followed by lymphocytes and macrophages in 24 h. Flow cytometry analysis of lymphoid cells on day 1 revealed that 38% were Ig+ (B cell marker), 60% MAC-2,3+ and 20% Thy 1.2+ of which only a small fraction were expressing CD4 on their surface. These numbers changed with time following implantation of the blocks. Initially, isolated adherent cells (macrophages) were resting, with low phagocytic activity. Cells isolated from blocks at later time points were activated, as evidenced by their increased ability to ingest fluoresceinated beads. The secretion patterns of cells trafficking to murine rIL-1 containing agarose blocks were examined. TNF, IL-6 and antibody secreting cells were found. No IL-2 was detected at any time. We believe that this model will be of value in studies of local actions of cytokines.

Lymphoproliferative responses to mitogens and HIV-1 envelope glycoprotein among volunteers vaccinated with recombinant gp160.

The protective immune response to human immunodeficiency virus type 1 (HIV-1) induced by vaccination will likely include cellular immune responses. We measured lymphoproliferative responses in persons vaccinated with a baculovirus-derived recombinant gp160 candidate AIDS vaccine. Twelve volunteers received either 40 micrograms of rgp160, 80 micrograms of rgp160, hepatitis B vaccine, or alum adjuvant alone on days 0, 30, and 180. Peripheral blood lymphocytes were collected on days 0, 28, 60, 120, 210, and 270 and were cryopreserved. Lymphocyte proliferation to mitogens and rgp160 with and without interleukin-2 stimulation were determined, and lymphokine production and antibody synthesis were measured. All vaccinees responded normally to stimulation with phytohemagglutinin and concanavalin A. One of 3 vaccinees who received 40 micrograms of rgp160, 2 of 2 vaccinees who received 80 micrograms of rgp160, and no controls developed rgp160-specific lymphoproliferative responses. No differences in the production of lymphokines (interleukin-2 and interferon-gamma) after stimulation with mitogens or rgp160 were found when rgp160 vaccinees and controls were compared. We conclude that rgp160 candidate vaccine induces antigen-specific lymphoproliferative responses in humans and does not interfere with immunocompetence as measured by in vitro responses to mitogen stimulation.

Vertical transmission of West Nile virus by Culex and Aedes species mosquitoes.

Experiments were conducted to determine whether West Nile (WN) virus was transmitted vertically by colonized strains of Aedes albopictus, Ae. aegypti, and Culex tritaeniorhynchus. Female mosquitoes were infected by intrathoracic inoculation with WN virus, and the F1 progeny were tested for virus by the fluorescence antibody technique and the newborn mouse assay. Each of the three mosquito species transmitted WN virus to F1 adults derived from immature forms reared at 26 degrees C. The minimal filial infection rate (MFIR) ranged from 1:124 to 1:138 for Ae. albopictus, from 1:62 to 1:172 for Ae. aegypti, and from 1:325 to 1:859 for Cx. tritaeniorhynchus. The MFIR for Cx. tritaeniorhynchus reared at 20 degrees C was 1:213 for larvae and 1:390 for pupae, and 1:208 for larvae and 1:554 for pupae reared at 26 degrees C. These data are the first reported evidence of vertical transmission of WN virus by mosquitoes, and therefore warrant further studies to determine whether vertical transmission occurs among WN viral-infected mosquitoes in nature.

Genetic variation for West Nile virus susceptibility in Culex tritaeniorhynchus.

Mutant and geographical strains of Culex tritaeniorhynchus were compared for West Nile (WN) virus susceptibility by feeding on a high-titered blood-virus suspension. Eleven strains also were selected from 2-21 generations for an increase and/or a reduction of oral susceptibility using 90% and 10% infective virus doses, respectively. Only one of the 20 strains tested, e ma, was significantly less susceptible than the control strain. In the selection experiments, none of the strains showed a consistent decrease in susceptibility, but the Changa Manga II (CM) strain showed a sustained increase in susceptibility from generations F11-F21 when selection was discontinued. Reciprocal cross-matings and back-crosses were set up between the selected CM strain and two of the morphological mutant strains, e ma and re e ae, carrying homozygous recessive markers. The resulting progeny were tested for susceptibility to WN virus infection and the ability to replicate virus to high-titers after infection. These results suggest that the trait of increased susceptibility is dominant over resistance. The enhanced ability of infected mosquitoes to replicate WN virus showed partial dominance. Both of these traits appear to be polyfactorial, and are apparently associated with more than one chromosome in Cx. tritaeniorhynchus.

Characteristics of Shigella sonnei infection of volunteers: signs, symptoms, immune responses, changes in selected cytokines and acute-phase substances.

Shigella sonnei infection resulting from oral administration of 500 colony-forming units was followed in 11 volunteers with the objective of studying the immune response and pathogenesis. Characterization of infection included recording of signs and symptoms, excretion of S. sonnei in stool, measurement of humoral tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), interferon-gamma (IFN-gamma), C-reactive protein, IL-2 receptor, soluble CD8, antibody-antigen complexes, and endotoxin. Measurements were also made of the immune response including lymphocytes secreting antibody to S. sonnei O antigen and serum antibody to this antigen. Six of the volunteers developed typical shigellosis with excretion of bacteria in stool and systemic signs and symptoms, three excreted bacteria but did not show illness, and two showed no evidence of infection or illness. Shigellosis was characterized by excretion in stool of S. sonnei beginning on average 1.3 days after ingestion. Excretion of S. sonnei (mean of time of the first positive cultures) was followed in sequence by the onset of increases in TNF-alpha (10 hr), liquid stools (14 hr), fever and dysentery (18 hr), IFN-gamma (22 hr), and C-reactive protein (34 hr). A S. sonnei-specific immune response was demonstrated somewhat later, between days 4 and 7 postinfection by antibody-secreting cells, and between days 7 and 14 postinfection by humoral antibody. Shigellosis was not associated with increased humoral IL-1 beta, endotoxin, or antigen-antibody complexes.

Estimate of Plasmodium falciparum sporozoite content of Anopheles stephensi used to challenge human volunteers.

Plasmodium falciparum infected Anopheles stephensi, taken from a group of mosquitoes which had been used to challenge recipients of (NANP)3-TT vaccine, were tested for P. falciparum sporozoite content by an immunoradiometric assay. Seventy-six percent were infected with mean and median sporozoite equivalents per mosquito of 220,994 and 217,398, respectively (SD = 54,911). This sporozoite density is greater than that usually found in the field. These data suggest that this challenge for evaluating P. falciparum sporozoite vaccines is a demanding test of immunity.

Pre-exposure anti-Campylobacter jejuni immunoglobulin a levels associated with reduced risk of Campylobacter diarrhea in adults traveling to Thailand.

Diarrhea history questionnaires were administered to 369 U.S. military volunteers before and after deployment to Thailand. Additionally, blood samples obtained from a subset of 221 volunteers 1-3 weeks previously and 3-4 weeks after their deployment were tested by enzyme-linked immunosorbent assay for immunoglobulin A to Campylobacter jejuni. Stool samples from personnel (including volunteers) contracting diarrhea in Thailand were cultured for enteric pathogens. Overall, 35.2% (130 of 369) of questionnaire respondents reported one or more diarrhea episodes during their trip. Volunteers with pretravel anti-C. jejuni reciprocal titers < or = 450 were 1.6 times as likely to have had diarrhea during their stay in Thailand compared with those with pretravel titers > 450 (39.7% versus 25.3%; P = 0.05). The symptomatic seroconversion, or attributable Campylobacter diarrhea attack rate, for the 1-month exercise was 12.7% (28 of 221). The symptomatic seroconversion rate in nonimmune (titer < or = 450) volunteers was 17.1%, whereas that in immune volunteers was only 4.0% (P = 0.002). Campylobacter jejuni or C. coli were recovered from 32.9% (56 of 170) of stool samples cultured and were the most commonly identified enteropathogens. Campylobacter diarrhea was associated with elevated temperatures, fecal red cells, and fecal white blood cells. The results of this study show that Campylobacter continues to represent a significant health threat to Western travelers to Thailand, but many of these travelers have preexisting Campylobacter immunity that protects them from clinically significant Campylobacter enteritis.

West Nile virus in Pakistan. III. Comparative vector capability of Culex tritaeniorhynchus and eight other species of mosquitoes.

Eight species of mosquitoes from Pakistan were compared with Culex tritaeniorhynchus as experimental vectors of West Nile (WN) virus. When fed by the membrane or cotton-pledget methods on a dose of WN virus 100% infective for Cx tritaeniorhynchus, 95% and 73% of the females of Cx fuscocephala and Cx pseudovishnui became infected, respectively. Cx quinquefasciatus, Cx univittatus, Aedes albopictus, Ae. caspius, Ae. indicus and Ae. lineatopennis were all significantly less susceptible than Cx tritaeniorhynchus. In agreement with the single dose comparisons, the median per os infective dose of WN virus for Cx fuscocephala, Cx pseudovishnui and Ae. caspius was substantially greater than for Cx tritaeniorhynchus. The median parenteral infective dose for all six species tested was less than 1 SMICLD50. Both Cx tritaeniorhynchus and Cx quinquefasciatus were more susceptible to infection with WN virus when fed on viraemic chickens than when fed on defibrinated blood using cotton pledgets or membranes. After infection by intrathoracic inoculation, only Ae. indicus and Ae. lineatopennis showed a reduced ability to transmit WN virus when compared to Cx tritaeniorhynchus.

West Nile virus in Pakistan. 1. Sero-epidemiological studies in Punjab Province.

Serum samples collected during 1978-79 from residents of the Chiniot and Changa Manga National Forest (CMF) areas of Punjab Province, Pakistan, had over-all neutralizing (N) antibody positive rates for West Nile (WN) virus of 32.8% (n = 192) and 38.5% (n = 239), respectively. Comparison of the age-specific antibody rates indicated that the pattern of exposure to infection was different in the two areas. Samples from a 1968 serosurvey of residents of the CMF area had an age-specific N antibody profile similar to the 1978 CMF sample, but both the over-all N and haemagglutination-inhibition (HI) antibody positive rates were much higher in the 1968 sample. When tested against antigen prepared from the Pakistan I-746 strain of WN virus, the percentage of sera HI antibody positive and the geometric mean titre of the sera were significantly higher than when tested against the Egypt-101 antigen. One of 124 and 11 of 50 sera from the 1978 and 1968 samples from CMF exhibited detectable HI antibody against dengue-3 virus, respectively, indicating cross-reacting flavivirus antibody was present. None of the positive sera had a higher titre against dengue-3 than against WN virus, but four of the 1968 sera reacted to equal titre against both antigens. During the 1978-79 CMF survey, serum samples from domestic and wild animals were tested for WN virus antibody. Of the 317 wild birds captured, 85 were N-antibody positive. The only frequently bled mammal was the Indian cow, from which 21 of 58 samples were positive for WN antibody.

Estimate of anti-Plasmodium falciparum sporozoite activity in humans vaccinated with synthetic circumsporozoite protein (NANP)3.

A mathematical model was defined to estimate the degree of in vivo activity against Plasmodium falciparum sporozoites expressed by volunteers vaccinated with a synthetic peptide comprising the immunodominant epitope of the circumsporozoite protein. Relative to the course of infection in non-immunized controls, infections in vaccinated volunteers corresponded to the neutralization or delay of development of greater than 99% of challenge sporozoites.

Carcinogenic and co-carcinogenic studies of thiram on mouse skin.

Thiram (tetramethyl thiuram disulfide), a carbamate fungicide, is used in the rubber processing industry as an accelerator and vulcanizing agent. Previous studies evaluated the tumorigenic potential of thiram in rodents, but failed to provide conclusive results. In the present study the tumorigenic potential of thiram was evaluated in Swiss albino mice by a two-stage initiation-promotion protocol and a long-term in vivo bioassay for carcinogenicity. Results revealed that following tumour initiation with thiram and promotion with 12-O-tetradecanoyl phorbol 13-acetate, skin tumours developed, mostly at the site of treatment (dorsal skin) in single and multiple dose-initiated animals. Similarly, papillomatous growths were observed on the dorsal skin of the mice initiated with a single subcarcinogenic dose of dimethylbenzanthracene and promoted with thiram. Thiram failed to provoke tumorigenesis when tested as a complete carcinogen for up to 52 wk and thereafter the study was terminated due to increased mortality. It is concluded that thiram has both tumour initiating and tumour-promoting potential in both sexes of Swiss albino mice following topical exposure at the tested dose level.

Carcinogenicity and co-carcinogenicity studies on propoxur in mouse skin.

Propoxur (2-isopropoxyphenyl methylcarbamate) is a widely used broad spectrum carbamate insecticide mainly used to control household pests. Propoxur exposure is reported to inhibit cholinesterase activity in rodents. Apart from other toxic effects, propoxur was found to possess tumorigenic activity in rats after oral administration. Propoxur does not produce tumours in mice or hamsters, or bladder hyperplasia in dogs and monkeys following oral feeding. In this set of investigations the complete carcinogenic, tumour initiating and promoting potential of propoxur was evaluated in male and female Swiss albino mice, since no information was available following dermal exposure of propoxur. The animals were exposed to propoxur through topical painting on the interscapular region at a dose of 100 mg/kg body weight. The results revealed that propoxur has tumour promoting potential on mouse skin following a two-stage initiation-promotion protocol, but it failed to induce the tumour(s) at a significant level, when tested for tumour initiating and complete carcinogenic property.

Dual infections of Culex tritaeniorhynchus with West Nile virus and Nosema algerae.

Culex tritaeniorhynchus females infected with the microsporidian Nosema algerae, and uninfected control females were compared for susceptibility to infection with West Nile (WN) virus and for the ability to transmit virus. When fed on a high titered dose fo virus, 95% of the control females became infected, whereas only 65% of the N. algerae-infected females were infected with WN virus. However, at two lower viral doses, no differences in susceptibility were observed. No significant differences in transmission ability were found between the N. algerae-infected and control females when tested at 10, 14, and 21 days after infection with WN virus. Also, in mosquitoes dually infected with N. algerae and WN virus, neither agent affected the ability of the other to replicate.

Comparison of vector competence for West Nile virus of colonized populations of Culex tritaeniorhynchus from southern Asia and the Far East.

Seven colonized stocks of Cx. tritaeniorhynchus from different geographic areas of Southern Asia and the Far East were assayed for susceptibility to WN virus infection by membrane feeding and by intrathoracic inoculation. Infected females also were tested for their ability to transmit virus to baby mice. No geographic pattern of differential susceptibility to WN virus infection was apparent from the experiments; however, the per os ID50 of one strain from Khulna, Bangladesh was over 10-fold greater than the ID50's of stocks from Karachi, Pakistan and Sendai, Japan. No difference in susceptibility was found by parenteral inoculation of virus. Likewise, greater than or equal to 90% of infected females from all the colonies were able to transmit virus.