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Biomedical subjects

B Kay

Publications and source records attributed to B Kay.

At least 19 recordsLinked to original sources

Evidence that inactivated oral cholera vaccines both prevent and mitigate Vibrio cholerae O1 infections in a cholera-endemic area.

In a randomized, placebo-controlled field trial of B subunit-killed whole cell (BS-WC) and killed whole cell only (WC) inactivated oral cholera vaccines in rural Bangladesh, active surveillance of selected neighborhoods during the first year after vaccination identified 127 Vibrio cholerae O1 infections among 3285 three-dose recipients. For each vaccine, protective efficacy was greater against symptomatic (57%, P < .05 for BS-WC; 58%, P < .05 for WC) than against asymptomatic infections (46%, P < .05 for BS-WC; 32%, P = .09 for WC), and protection against each grade of infection was demonstrable for both the classical and El Tor biotypes. Although vaccine protection against symptomatic infections was evident in both young children and older persons, only persons vaccinated at age > 5 years were protected against asymptomatic infections. These results suggest that the inactivated oral vaccines acted both to protect against intestinal colonization by V. cholerae O1 and to interrupt the pathogenic sequence of established infections.

Adolescent

Evaluation in volunteers of a candidate live oral attenuated Salmonella typhi vector vaccine.

Candidate vector vaccine strain CVD 906 (aroC- and aroD- derivative of virulent Salmonella typhi strain ISP1820) was evaluated in phase 1 clinical trials. The first nine volunteers ingested a single dose of 5 x 10(7) CVD 906 bacilli. At this dose CVD 906 stimulates remarkable systemic and mucosal immune responses, inasmuch as 89% of volunteers developed marked serum antibody levels to S. typhi antigens and high numbers of antigen-specific gut-derived antibody-secreting cells. Four (44%) volunteers developed asymptomatic vaccinemia 4-10 d after immunization and all volunteers excreted CVD 906 on at least one occasion. However, two volunteers developed febrile adverse reactions, one on the day of vaccination and the other on day 4. Of 11 volunteers who ingested a single dose of 5 x 10(3) CVD 906 bacilli, none displayed side effects but 27% developed significant serum responses to S. typhi LPS. In vitro, CVD 906 replicates for only nine generations in pooled human serum, indicating that CVD 906 growth is limited in this physiologically relevant medium. In phorbol myristate acetate-induced U937 human macrophage-like cells, CVD 906 replicates intracellularly to a lesser extent than parent strain ISP1820. Although, strain CVD 906 is attenuated and highly immunogenic, the occasional febrile reactions at high doses indicate that further attenuation of this strain is necessary.

Antibodies, Bacterial

[Mononuclear cell activation in status asthmaticus].

Evidence was provided by the authors, that the activity of circulating mononuclear cells is increased in status asthmaticus. An increased spontaneous secretion of chemotactic cytokin was found into the culture medium. There was no further increase in neutrophil chemotactic activity after 24 hours. In all patients a reduction was observed in the amount of neutrophil chemotactic activity after one week therapy, which is probably due to steroid treatment. No eosinophil chemotactic activity could be detected in the mononuclear cell supernatant derived from patients with acute severe asthma. The chemotactic activity was measured using a 48-well microchemotactic chamber. This mononuclear cell derived cytokin may play a role in genesis of asthmatic bronchial inflammation and provides further evidence that mononuclear cell activation is a feature of status asthmaticus.

Asthma

Challenge studies in volunteers using Escherichia coli strains with diffuse adherence to HEp-2 cells.

Diffusely adherent (DA) Escherichia coli, a newly described category, has been associated with diarrhea in children in some but not all epidemiologic studies. To investigate its diarrheagenic potential, two strains of DA E. coli were fed to adult volunteers in doses of 10(5)-10(10) colony-forming units. None of 22 volunteers who received strain 57-1 or of 21 who received strain C1845 developed symptoms of diarrhea as defined for this study. All volunteers shed the challenge DA E. coli in their stools. Duodenal string cultures were positive in some volunteers only at the highest doses. Only 6 developed IgG or IgA antibodies to whole DA E. coli. Thus, the pathogenic potential of DA E. coli could not be shown in this model. Further studies are needed to characterize potential virulence factors of DA E. coli that might distinguish a pathogenic subset.

Adult

The effect of diclofenac and nefopam on postoperative dental pain.

Eighty-two outpatients who received general anaesthesia for surgical removal of maxillary or mandibular third molars were given either diclofenac 75 mg or nefopam 20 mg intramuscularly for postoperative pain control. They and the control group were also allowed oral paracetamol as required. The results showed that there was no significant pain relief from these single intramuscular injections.

Adult

Laboratory observations on Plesiomonas shigelloides strains isolated from children with diarrhea in Peru.

Eleven strains of Plesiomonas shigelloides isolated from 10 Peruvian children with diarrhea were examined. All the strains were resistant to two or more antibiotics, most commonly ampicillin, gentamicin, erythromycin, kanamycin, and streptomycin. The strains were all negative in the Sereny and cell culture assays used to test for enteroinvasiveness. One strain showed cytotoxic activity on Vero cells. The strains showed no antigenic relationship with Shigella organisms. Both bioassays and enzyme-linked immunosorbent assays used for detection of Escherichia coli enterotoxins were negative. Nucleic acid probes for such toxins likewise gave negative results. The strains all possessed a large (approximately 200-megadalton) plasmid in addition to one or more other plasmids. Several different plasmid profiles were observed among these 11 P. shigelloides strains, indicating that the isolates were not acquired from a common source or from a single bacterial clone.

Child

Use of atracurium or vecuronium to prolong the action of tubocurarine.

Forty patients received tubocurarine in a dose greater than ED90. When neuromuscular function had recovered to amplitude of the first contraction of the train-of-four equals 10% of control, a small increment of atracurium or vecuronium was administered, repeating the same increment at each subsequent recovery to 10%. The intensity and duration of the neuromuscular block following the first increment was always greater than that of subsequent increments. The duration and intensity of the block was progressively reduced with subsequent increments until the responses to further increments were unchanged. These final means at steady state were: group 1 (atracurium 1.1 mg) 6.4 (0.3) min; group 2 (atracurium 2.0 mg) 8.2 (0.9) min; group 3 (vecuronium 0.25 mg) 5.8 (0.4) min; group 4 (vecuronium 0.5 mg) 13.2 (0.4) min.

Adult

Use of monoclonal antibodies to type Shigella flexneri in Bangladesh.

A panel of 10 mouse and rat monoclonal antibodies specific for different type- and group-specific O-antigenic determinants of Shigella flexneri lipopolysaccharide was used to serotype 240 isolates of S. flexneri from Bangladesh. Three immunoglobulin M antibodies were used in a direct slide agglutination test; seven immunoglobulin G antibodies were absorbed to Staphylococcus aureus and used in a coagglutination assay. All but 13 of the isolates could be serotyped by using the monclonal antibodies. The six most common serotypes were (in descending order) 2a, 2b, Y (E1037), 1a, 3a, and 1b and accounted for more than 80% of all isolates. Two of the nontypable strains were found to be of a new provisional serotype of S. flexneri (T. Wehler and N.I.A. Carlin, Eur. J. Biochem. 176:471-476, 1988). The 11 remaining strains were found to be rough and therefore nontypable. The serotyping scheme based on the panel of monoclonal antibodies is specific and holds the potential to be developed into a useful tool for epidemiological investigation. The study also demonstrates that the recently described E1037 antigen is commonly found among at least four serotypes (4a, 6, X, and Y) of S. flexneri.

Agglutination Tests

Parasitic, bacterial and viral pathogens isolated from diarrhoeal and routine stool specimens of urban Bangladeshi children.

Few data exist in Bangladesh on longitudinal, community-based studies of bacterial or parasitic pathogens identified in routine and diarrhoeal stools of urban dwelling children. We undertook the following study on 343 children of age less than 6 years who resided in one of 51 slum settings in Dhaka, Bangladesh, between October 1984 and February 1986. Specimens from diarrhoeal episodes and from routine stools obtained at 3-monthly intervals were examined for parasites, rotavirus and pathogenic bacteria. Parasites were isolated from 509 (51%) of the 1006 routine stools and from 95 (42%) of the 225 diarrhoeal stools. Isolation rates steadily increased with age. Ascaris lumbricoides and Trichuris trichiura accounted for approximately 80% of all parasitic isolates in routine and diarrhoeal stools. Giardia lamblia was isolated from 11% diarrhoeal stools. Entamoeba histolytica was an uncommon isolate (less than 1%). Bacterial pathogens were identified in 55 (24%) of the diarrhoeal stools but were identified in only 164 (16%) of the 1028 routine stools examined (P less than 0.01). Toxigenic Escherichia coli, Shigellae and Campylobacter were the most frequent isolates from diarrhoeal and routine specimens. This pathogen profile appears to be more in keeping with that from urban settings in other developing countries than from rural Bangladesh, suggesting that extrapolations from rural-based data should not be made for urban settings.

Age Factors

Oral nalbuphine for the treatment of pain after dental extractions.

A randomized, double-blind comparison of nalbuphine 30 mg or 60 mg by mouth and dihydrocodeine 30 mg by mouth was conducted in 75 patients with moderate to severe pain after surgery for dental extractions under general anaesthesia. A significant reduction in pain intensity followed each treatment and persisted throughout the 4-h observation period after nalbuphine, but only for 3 h after dihydrocodeine was given. Reduction in pain intensity was significantly greater 2, 3 and 4 h after the use of nalbuphine 60 mg than following dihydrocodeine 30 mg, and the mean total pain intensity difference was greater following nalbuphine 60 mg than following dihydrocodeine. Nalbuphine 60 mg effectively provided complete or good pain relief in more than 50% of the patients and only three patients in this group required additional analgesia during the period of observation, compared with nine patients in each of the other groups. However, the patients who received nalbuphine 30 mg had a significantly higher mean pain intensity before treatment than those in the other groups. The side-effects encountered were those typical of opioid medication; there were no statistically significant differences between the groups.

Administration, Oral

A focused casework approach to the treatment of child abuse: a controlled comparison.

Two contrasting therapies for the treatment of child abuse were compared in a randomised design: a focused casework approach to the whole family and a structured play therapy approach to the child. The Patterson coding system was used as an outcome measure. There was a high drop-out rate from both the therapies, but of those who completed the treatment, there was a greater improvement in the focused casework regime on some of the comparisons made.

Adolescent

Recurrent aphthous stomatitis of the Behçet's type: successful treatment with thalidomide.

A 48-year-old man with a 27-year history of debilitating recurrent aphthous stomatitis major and pustular skin lesions was treated successfully with thalidomide. Side effects have not been encountered during a 6-month symptom-free period, while he has taken 25 mg per day. The drug is currently unavailable in this country except for the treatment of leprosy. It is hoped that publication of the dramatic response to thalidomide in this one instance will encourage greater interest in this potentially useful drug.

Behcet Syndrome

Disposition of nalbuphine in patients undergoing general anaesthesia.

The pharmacokinetics of nalbuphine 20 mg i.v. were studied in 10 patients undergoing lower abdominal or body surface surgery. Blood sampling was carried out for 600 min after injection and drug concentrations were measured by HPLC using electrochemical detection. Disposition was best described as a triexponential function, with a mean elimination half-life of 135.5 min. Mean residence time, clearance, and volumes of distribution, Vss and V beta, were determined by a model independent method, and gave mean values of 149.7 min (MRT), 1095 ml min-1 (ClP), 159.9 litre (Vss) and 207.1 litre (V beta).

Adult

Economy in the use of muscle relaxants. Vecuronium after pancuronium.

Vecuronium is an intermediate duration, non-depolarising muscle relaxant. When used during prolonged procedures, it may be given by intermittent injection, by continuous infusion or by a single very large dose at the start of anaesthesia. It may also be used to maintain relaxation after the initial use of a long-acting agent, such as pancuronium. This study demonstrates that the effect of a dose of vecuronium used in this fashion is increased when interaction with pancuronium takes place. The clinical and theoretical implications of this observation are discussed.

Adult