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Biomedical subjects

R C Ballard

Publications and source records attributed to R C Ballard.

At least 73 records · Page 4Linked to original sources
PubMed1986

Ulcerative balanoposthitis associated with non-syphilitic spirochaetal infection.

Ulcerative balanoposthitis associated with non-syphilitic spirochaetal infection was found in 41 (12%) of 344 consecutive men with genital ulcer disease in two clinics in South Africa. All patients with non-syphilitic spirochaetal infection were uncircumcised. Non-syphilitic treponemes were seen in only two of 60 uncircumcised men who had urethritis without genital ulceration. In 14 patients with ulcerative balanoposthitis no cause of genital ulceration could be identified. Most patients presented with large, serpiginous, superficial, foul smelling, and tender ulcers, the base of which was purulent with undermined edges. Non-tender inguinal lymphadenopathy was present in seven of 14 patients. One female sexual partner of a patient with non-syphilitic spirochaetal infection had a vaginal infection with non-syphilitic spirochaetes.

Humans↗
PubMed1984

Microbiological studies during the perinatal period. An attempt to correlate selected bacterial and viral infections with intra-uterine deaths and preterm labour.

An investigation of the genital, amniotic fluid, placental and neonatal microflora in a population with a high prevalence of amniotic fluid infections and perinatal deaths is reported. Women presenting with preterm labour and intra-uterine death were investigated for the presence in vaginal secretions of a selected variety of pathogenic organisms, and the findings in these patients were compared with those in three groups of controls who presented with normal labour at term or late delivery or who required elective caesarean section as a result of cephalopelvic disproportion. Indirect evidence of infection was also sought by assaying cord blood for immunoglobulin levels and by testing for specific antibodies to well-known congenitally acquired pathogens. The results showed a significant relationship between gonococcal infection, serological evidence of Chlamydia trachomatis infection and preterm labour.

Amniotic Fluid↗
PubMed1983

Problems in the management of sexually transmitted diseases in South Africa.

On the subcontinent sexually transmitted diseases present considerable diagnostic and therapeutic problems. With the recognition of vast numbers of non-gonococcal and chancroid infections, penicillin therapy is no longer adequate. This article outlines an approach to the management of urethritis and genital ulcer disease, giving suitable guidelines for the treatment of these 'disease syndromes'. The management of sexually transmitted vaginal discharges is also discussed, and the relevance of the rapidly performed 'wet mount' in the diagnosis of those discharges arising from the vaginal wall is stressed.

Acute Disease↗
PubMed1983

Isolation of Haemophilus ducreyi from genital ulcerations in white men in Johannesburg.

An analysis of sexually acquired genital ulcerations in 31 White patients who were examined microbiologically in Johannesburg showed Haemophilus ducreyi to be the causative agent in 23 (74%), whereas syphilis was the confirmed diagnosis in only 6 (19%). All the H. ducreyi isolates produced beta-lactamase. Previously, chancroid was considered to be an infrequent cause of genital ulceration in this population group. Unlike those with syphilitic ulceration, patients with chancroid usually do not respond to penicillin. The improved isolation procedures for H. ducreyi now enable the laboratory to confirm most cases.

Chancroid↗
PubMed1983

Problems in the diagnosis of lymphogranuloma venereum. A review of 6 cases.

Six cases of lymphogranuloma venereum are described in White South Africans. All initially presented diagnostic problems. This sexually transmitted disease is uncommon in South Africa, and 5 of the 6 patients presented with inguinal lymphadenopathy without a primary lesion. The value of serological tests in the diagnosis of this disease is emphasized.

Adult↗
PubMed1983

Trachoma in South Africa.

Trachoma remains the most common cause of preventable blindness in certain areas of the northern Transvaal region of South Africa. Results of epidemiological studies in the area indicate that trachoma is a familial disease with young children acting as the main source of infection within the family. Elderly women who have lived in these areas for long periods of time are at greater risk of blindness and impaired vision from the disease. Genital tract carriage of Chlamydia trachomatis is relatively infrequent in these trachoma-endemic areas and no evidence of eye-to-eye transmission of oculo-genital serotypes of C. trachomatis could be demonstrated.

Adolescent↗
PubMed1983

Community participation in the control of trachoma in Gazankulu.

Groups of villagers, the care groups, are involved in prevention and treatment of trachoma within their own communities. The effect of the scheme on standards of hygiene and prevalence of trachoma has been evaluated by randomised cluster sampling methods. The number of households who were digging refuse pits, acquired individual face cloths and were aware of the role of good hygiene in the prevention of trachoma exceeded significantly those in (control) villages without a care group, in contrast the acquisition of pit latrines showed an insignificant increase. The prevalence and intensity of active trachoma was found to be significantly reduced as a result of the intervention of the care groups. This scheme has been totally integrated into the primary health care system of the area.

Africa, Southern↗
PubMed1983

Treatment of chancroid with erythromycin. A clinical and microbiological appraisal.

One hundred and thirty seven patients presenting with genital ulcerations from which Haemophilus ducreyi was isolated were treated with erythromycin stearate 500 mg every six hours for seven days. Of these, 91 (66%) had associated inguinal lymphadenopathy. Only two of the 100 patients who returned after one week showed no clinical improvement. Despite decrease in size H ducreyi was reisolated from the ulcers of three patients, two of whom had not complied with treatment. The patients were treated for a further week either with erythromycin or with a placebo preparation and on day 14 no discernible difference in clinical response was evident. H ducreyi was not reisolated from any lesion. In contrast, the natural course of development of associated lymphadenopathy was not modified by treatment. H ducreyi was not, however, isolated from any gland after the start of treatment. Side effects attributable to erythromycin were minimal and treatment had to be discontinued in only two patients. This study clearly indicates that treatment with erythromycin for one week results in rapid healing of lesions and the elimination of H ducreyi from both ulcers and associated lymph glands.

Chancroid↗
PubMed1982

Effects of simulated increased gravity on the rate of aging of rats: implications for the rate of living theory of aging.

Ever since Pearl proposed the rate of living theory of aging numerous studies have demonstrated its validity in poikilotherms. In mammals, however, satisfactory experimental demonstration is still lacking because an externally imposed increase of basal metabolic rate of these animals (e.g. by placement in the cold) is usually accompanied by general homeostatic disturbance and stress. The present study was based on the finding that rats exposed to slightly increased gravity are able to adapt with little chronic stress but at a higher level of basal metabolic expenditure (increased 'rate of living'). The rate of aging of 17-mth-old rats that had been exposed to 3.14 times normal gravity in an animal centrifuge for 8 mth was larger than of controls as shown by apparently elevated lipofuscin content in heart and kidney, reduced numbers and increased size of mitochondria of heart tissue, and inferior liver mitochondria respiration (reduced 'efficiency': 20% larger ADP: 0 ratio, P less than 0.01; reduced 'speed': 8% lower respiratory control ratio, P less than 0.05). On the other hand, steady-state food intake per day per kg body weight, which is presumably proportional to 'rate of living' or specific basal metabolic expenditure, was about 18% higher than in controls (P less than 0.01) after an initial 2-mth adaptation period. Finally, though half of the centrifuged animals lived only a little shorter than controls (average about 343 vs. 364 days on the centrifuge, difference statistically nonsignificant), the remaining half (longest survivors) lived on the centrifuge an average of 520 days (range 483-572) compared to an average of 574 days (range 502-615) for controls, computed from onset of centrifugation, or 11% shorter (P less than 0.01). Therefore, these results show that a moderate increase of the level of basal metabolism of young adult rats adapted to hypergravity compared to controls in normal gravity is accompanied by a roughly similar increase in the rate of organ aging and reduction of survival, in agreement with Pearl's rate of living theory of aging, previously experimentally demonstrated only in poikilotherms.

Aging↗
PubMed1982

Accelerated aging of fasted Drosophila. Preservation of physiological function and cellular fine structure by thiazolidine carboxylic acid (TCA).

Thiazolidine carboxylic acid (TCA) is a natural liver metabolite whose Mg-salt increased lifespan of flies and mice (Miquel and Economos, 1979, Exp. Geront. 14: 279). We studied the physiological and cellular fine structural effects of various concentrations of TCA in the food of male Drosophila. Flies on 0.3% TCA at 27 degrees C had a reduced oxygen consumption rate (about 20% less than controls) at 3 wks of age while their mating capacity and speed of mating were preserved; the flies lived in various experiments 20-30% longer than controls. Apparently TCA improved the metabolic efficiency of the flies (possibly from less "waste" of energy due to improved mitochondrial coupling). However, flies on 0.9% TCA had a reduced mating capacity and lifespan (:toxicity) while at 0.1% TCA was ineffective. A similar dose-response relationship was found in young flies treated with TCA for 1 week and then deprived of food and water, a procedure found to induce accelerated physiological aging. TCA at the 0.3% and 0.6% level reduced the speed of development and the size of the enclosed flies. Electron microscopic investigation of wing muscle showed that 0.3% TCA had a protective effect on cellular fine structure. Though in starved controls (40% survivors after 24 hours of starvation) there was a total absence of glycogen granules, and a striking shrinkage and densification of mitochondria, TCA to a large extent protected muscle cells from these effects of starvation.

Aging↗
PubMed1982

Characterisation of an unusual bacterium isolated from genital ulcers.

The preliminary characterisation of an unusual gram-negative bacillus isolated from genital ulcers in Swaziland is reported. Like Haemophilus ducreyi, it is an oxidase positive, nitrate-reductase-positive gram-negative rod that forms streptobacillary chains in some circumstances; it was therefore called the "ducreyi-like bacterium" (DLB). Distinguishing features of DLB are production of alpha-haemolysis on horse-blood agar, stimulation of growth by a microaerophilic atmosphere and by a factor produced by Staphylococcus aureus, a strongly positive porphyrin test, and a remarkable ability to undergo autolysis. DLB had a guanine + cytosine value of c. 50 mole% but it cannot be classified, even at the genus level, until more taxonomic data are obtained.

Bacteria↗
PubMed1982

In vitro susceptibility and cross-resistance of South African isolates of Neisseria gonorrhoeae to 14 antimicrobial agents.

One hundred isolates of Neisseria gonorrhoeae obtained from patients attending clinics in Johannesburg, South Africa, were tested by a broth dilution technique for their minimal inhibitory concentrations (MICs) of benzyl penicillin G, ampicillin, cefoxitin, cefuroxime, cefotaxime, ceftriaxone, ceftazidime, tetracycline, minocycline, doxycycline, spectinomycin, rosaramicin, chloramphenicol, and rosoxacin. None of the isolates tested produced beta-lactamase. The MICs of penicillin ranged from less than or equal to 0.007 to 0.5 micrograms/ml. The isolates were also very susceptible to rosaramicin (minimal concentration at which 50% of isolates were inhibited [MIC50] = 0.02 micrograms/ml) and to the new cephalosporins (cefotaxime MIC50 less than 0.007 micrograms/ml, ceftriaxone MIC50 less than 0.007 micrograms/ml, and ceftazidime MIC50 less than 0.007 micrograms/ml). By using regression analysis, good correlation was observed between the MICs of penicillin and those of the other agents, with the exception of ceftriaxone, spectinomycin, and rosaramicin. The MICs and the minimal bactericidal concentrations were within a log2 concentration of each other.

Anti-Bacterial Agents↗
PubMed1982

Antimicrobial susceptibility of 103 strains of Haemophilus ducreyi isolated in Johannesburg.

Of 103 strains of Haemophilus ducreyi isolated in Johannesburg, 96 produced beta-lactamase and were resistant to penicillin and ampicillin. Most strains showed resistance to tetracycline, sulfisoxazole, and sulfamethoxazole. All isolates were susceptible to rifampin, erythromycin, and cefoxitin, moderately susceptible to trimethoprim-sulfamethoxazole (1:19) and minocycline, and somewhat less susceptible to doxycycline.

Anti-Bacterial Agents↗
PubMed1981

The epidemiology and geographical distribution of trachoma in Lebowa.

The prevalence of active trachoma and its potentially blinding sequelae have been estimated in ten settlements scattered throughout rural Lebowa. The disease represents a major public health problem only in northern Lebowa where 25% of subjects over 60 years of age were found to be suffering form visual disability as a result of the infection. Although the disease is endemic in most other parts of lebowa it rarely causes blindness and impaired vision. A rational approach to the control of trachoma in the area which takes into account both local considerations and recent advances in the knowledge of the epidemiology of the disease is recommended.

Adolescent↗
PubMed1979

The pathology of trachoma in a black South African population. Light microscopical, histochemical and electron microscopical findings.

Conjunctival biopsy specimens from a Black South African population suffering from trachoma have been studied by light microscopy, histochemistry and electron microscopy. A wide spectrum of histopathological changes was noted at different ages. Large cystically dilated glands containing concretions were seen and histochemical and electron microscopical examination revealed that the concretion material consisted of the inspissated secretion of goblet cells and cell debris. The cell damage seen in trachoma may be caused by the release of lysosomal enzymes from inflammatory cells.

Adolescent↗
PubMed1978

A community approach to trachoma control in the Northern Transvaal.

Trachoma represents the largest single cause of preventable blindness in the Black population of the Northern Transvaal. Epidemiological and cultural considerations indicate the necessity of community involvement in trachoma control at the household level. Involvement of the community by means of groups of voluntary health workers (care groups) has proved to be effective and acceptable to the local inhabitants. These groups, who form part of the comprehensive health system, integrate trachoma control into the primary health care activities of the area.

Community Health Workers↗
PubMed1978

Trachoma in a rural South African community.

The prevalence of trachoma was studied in a representative sample of family units from a rural community. Evidence of current or previous infection was found in 82% of the total population, but there was a relatively low prevalence of intense upper tarsal disease. Most children acquire the disease within the first 3 yr of life, these primary infections having a tendency towards spontaneous cure without complications. The prevalence of active disease and potentially blinding sequelae is higher in elderly females than in males of the same age. Clinical and microbiological evidence suggests that trachoma is transmitted primarily within households in this community, the main source of infection appearing to be children of pre-school age. Chlamydiae were isolated from the eyes of children with intense upper tarsal disease, but not from elderly persons with similar clinical signs.

Adolescent↗