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Biomedical subjects

J W Dickerson

Publications and source records attributed to J W Dickerson.

At least 19 recordsLinked to original sources
PubMed1992

Blastomycosis: a reminder of Kentucky's other fungus.

Although not as common as Histoplasmosis, the disease caused by Blastomyces dermatitidis is also endemic in the Commonwealth of Kentucky. Greater clinical awareness of this systemic mycosis and the newer effective forms of treatment may lessen the significant morbidity and mortality of this potentially serious infection. To illustrate the varied manifestations of this illness, we contrast the presentation of an urban female with blastomycosis and atypical chest radiographic changes to the more classic features of blastomycosis described in the literature.

Adult↗
PubMed1991

Giardia lamblia and Cryptosporidium infections in child day-care centers in Fulton County, Georgia.

Risk factors for the introduction, spread and persistence of Cryptosporidium and Giardia lamblia infections in child day-care centers are not well understood. In 1989 and 1990 stool specimens were obtained from 292 diapered children attending 17 randomly selected day-care centers in Fulton County, GA; 8 (2.7%) children in 2 centers were infected with Cryptosporidium and 21 (7.2%) children in 7 centers were infected with Giardia. In 1986 the prevalence of Cryptosporidium and Giardia in these same centers had been 0.4 and 11.0%, respectively; the prevalence of Cryptosporidium, but not Giardia, increased significantly (P = 0.04) between 1986 and 1989 to 1990. Risk factors for Giardia infection included day-care attendance for greater than 3 months, the presence of toddlers in the classroom and the presence of other children in the household. Day-care centers with a Giardia-positive child in 1986 were not more likely to have an infected child in 1989 to 1990. Cryptosporidium, like Giardia, may be endemic in day-care centers in Fulton County.

Child Day Care Centers↗
PubMed1991

Purification and characterization of Giardia lamblia antigens in the feces of Mongolian gerbils.

In a recent study, we identified Giardia lamblia 65- and 70-kDa antigens in the feces of infected Mongolian gerbils. The 65-kDa antigen was from a strain isolated from a human with symptoms of giardiasis, and the 70-kDa antigen was from a strain isolated from a human with no symptoms of giardiasis. In this study, we used preparative electrophoresis and electroelution techniques to purify these antigens to a degree which showed a single discrete protein band on silver-stained polyacrylamide gels. By enzyme-linked immunoelectrotransfer blot, common epitopes on the 65- and 70-kDa antigens were indicated by their cross-reactivity with rabbit anti-65-kDa and anti-70-kDa sera. By indirect immunofluorescence assay, the cysts and trophozoites of the two strains cross-reacted with these sera. Of seven lectins tested, only concanavalin A bound to the 70-kDa antigen, suggesting a glycoprotein, and it possessed a low isoelectric point as assessed by preparative isoelectric focusing. Molecular mass estimations of these antigens by sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis were similar to the 65- and 70-kDa estimations obtained by native polyacrylamide gradient gel electrophoresis. Although the 65- and 70-kDa antigens proved to be resistant to 100 degrees C heat and stable in storage for up to 25 months at -20 degrees C, neither appeared to be the same as a fecal G. lamblia antigen with similar molecular mass found by other investigators. This suggests that variable G. lamblia antigens may be found in the feces of infected humans.

Animals↗
PubMed1991

The composition of body tissues (II). Fetus to young adult.

The composition of body tissues is a function of the age, nutrition, state of health and physical activity of the individual. In this paper, the effects of age on the composition of healthy tissues are reviewed. Eleven soft tissues (adipose tissue, blood--whole, brain--whole, heart, kidney, liver, lung, muscle--skeletal, placenta, skin and spleen) and cortical bone are considered. Elemental compositions, mass and electron densities are tabulated for the tissues, as a function of age, from fetus to young adult. Although the compositions given here are predominantly for healthy tissues, reported changes because of dietary influences are briefly discussed.

Adolescent↗
PubMed1991

Experimental Onchocerca volvulus infections in mangabey monkeys (Cercocebus atys) compared to infections in humans and chimpanzees (Pan troglodytes).

Three chimpanzees, three mangabey monkeys (Cercocebus atys), and 14 patas monkeys (Erythrocebus patas) were inoculated with L3 Onchocerca volvulus of Guatemalan origin. One chimpanzee and two mangabey monkeys developed antibody activity to at least three different antigens. Both mangabey monkeys recognized a 20 kDa antigen 3.5-5 months post-inoculation, and the monkeys and the chimpanzee developed antibody activity to 14 and 22 kDa antigens 7.5-13 months post-inoculation. One mangabey monkey and the chimpanzee became microfilaria-positive in skin snips at 16 and 21 months post-inoculation, respectively. Antibody activity to the 20 kDa antigen in the mangabey monkeys is noteworthy because of the prominence of this antigen among putatively immune persons living in onchocerciasis-endemic areas. The two mangabey monkeys responded parasitologically in a manner comparable to immune humans. No microfilariae were detected in one monkey and only scant numbers of microfilariae were observed in the second. The mangabey monkey may be a good animal model for the study of onchocerciasis.

Animals↗
PubMed1991

Bancroftian filariasis: long-term effects of treatment with diethylcarbamazine in a Haitian population.

Two groups of Wuchereria bancrofti-infected Haitians who had undergone treatment with diethylcarbamazine (DEC) were followed for up to five years after treatment to document the long-term effects of treatment on adult worms and microfilariae and on the recurrence of infection. One group of 69 persons who had received 12 daily treatments had a significant decrease in microfilaria levels until year 4, when a small number of individuals experienced a resurgence of this parasite stage in the peripheral blood. In a second group of 57 persons who had been treated weekly for 12 consecutive weeks, there was a greater reduction in the microfilaria levels following treatment, and for the full four years of followup, these levels remained more depressed than those of the group that received daily treatment. Our results indicate that DEC kills or permanently sterilizes adult W. bancrofti. Furthermore, these results demonstrate conclusively that in Haiti, the use of DEC provides long-term benefits to treated persons, even though they continue to reside in an area with endemic filariasis.

Animals↗
PubMed1991

The value of prescribed 'high-fibre' diets for the treatment of the irritable bowel syndrome.

The symptoms of 72 patients with irritable bowel syndrome were assessed by questionnaire before and 6 months after a high-fibre diet had been prescribed, to find whether those who achieved the highest fibre intake did any better than those with smaller intakes. Dietary fibre intakes were measured after 6 months by a 7-day weighed food inventory. There was a significant inverse association between the presence of symptoms and fibre intake for: incomplete defaecation, urgency and hard stools with total fibre intake; urgency and hard stools with cereal fibre intake; and borborygmi with fibre intake at breakfast. All patients with constipation, mucus, urgency or watery stools at the beginning of the study, and who were consuming more than 30 g fibre by the end, reported an improvement in these symptoms. Increasing intakes of fibre were not related in any way to abdominal distension, diarrhoea, flatulence or patient's feelings about the working of their bowels. Therefore, this study suggests that the symptoms which benefit most from the prescription of a high-fibre diet are hard stools, constipation and urgency.

Adult↗
PubMed1991

Infectivity of cryopreserved Giardia cysts for Mongolian gerbils (Meriones unguiculatus).

Although Giardia species trophozoites have been cryopreserved successfully, no report on the successful cryopreservation of cysts could be found. Using infectivity to Mongolian gerbils (Meriones unguiculatus) as a measure of cyst viability, we tested the viability of 4 strains of Giardia cysts that had been cryopreserved for 1-67 wk. Cysts were frozen in either Keister's medium or physiological saline, both containing 5% or 7.5% dimethylsulfoxide as the cryoprotectant. Viability of cryopreserved cysts was dependent upon the number of cysts inoculated, the length of time cysts were held at 4 C before cryopreservation, and the cryopreserving medium. Infection was established in gerbils by inoculating them with cysts that had been cryopreserved for up to 67 wk, cysts that had been held for less than 30 days before cryopreservation, and cysts frozen in Keister's medium. Saline appears to be unsuitable as a freezing medium for the cryopreservation of Giardia cysts.

Animals↗
PubMed1990

Antigenic variation of Giardia lamblia in the feces of Mongolian gerbils.

Enzyme-linked immunoelectrotransfer blot was used to study variations in Giardia lamblia antigens in extracts of feces from infected Mongolian gerbils. A 65-kilodalton antigen was found in feces that contained strain WB (ATCC 30957) cysts and in axenic culture of strains WB and CDC:0284:1 that contained trophozoites. The 65-kilodalton antigen from trophozoites of both strains was membrane associated. A 70-kilodalton antigen was found in feces that contained strain CDC:0284:1 cysts. It was persistent in 16 fecal collections and may be strain specific. Similar variations in antigens may occur in human feces. Coproimmunodiagnostic assays that use monoclonal antibodies will have to include all varieties of G. lamblia antigens present in the feces of giardiasis patients.

Animals↗
PubMed1990

A technique for microfilarial detection in preserved blood using nuclepore filters.

Nuclepore filtration is now the most widely used method of detecting microfilaremia, particularly if microfilariae are few in number. However, this system requires the blood sample to be processed promptly after collection. Using blood from Wuchereria bancrofti-infected patients, 3 solutions were tested to determine whether blood could be held for delayed processing. Of these, we identified 1, 2% formalin/10% Teepol, in which microfilaremic blood can be held for at least 9 mo without deterioration of microfilarial structure or decrease in microfilarial numbers. In addition, this mixture passed easily through a 5-microns filter at all times tested. Examination of more than 300 blood samples held in 2% formalin/10% Teepol showed that this solution can utilize the convenience and sensitivity of membrane filtration while eliminating the need to perform testing immediately after the blood is collected.

Animals↗
PubMed1989

Plasma amino acids in patients with senile dementia and in subjects with Down's syndrome at an age vulnerable to Alzheimer changes.

Plasma concentration of tryptophan, tyrosine, leucine and thiamine were reduced in senile dementia of Alzheimer type. In Down's syndrome, where Alzheimer-type histology appears consistently at an early age, there was a definite type of abnormality, raised concentrations of isoleucine, leucine, phenylalanine and cystine. Because of the competition between amino acids for transfer into the brain, either or both of these types of change could lie in the aetiological chain underlying the development of Alzheimer pathology. Alternatively, these patterns could reflect the requirements of aberrant central/peripheral protein turnover.

Adult↗
PubMed1989

Further evidence of a skewed distribution of microfilariae in capillary blood.

Reported are results for 23 Haitian patients with capillary Wuchereria bancrofti microfilaremias greater than 30 mf/20 cmm blood. In capillary blood, the number of microfilariae was 0.9 to 7.8 times greater than expected when compared with that in venous blood. When the values for venous blood and capillary blood from these high count patients were plotted, the simple linear regression y = a + bx (r2 = .36) and the exponential function y = aebx (r2 = .34) both represented the relationship. However, when values for high and low count patients were plotted, the power function y = axb (r2 = 0.82) best described the relationship between the number of microfilariae in venous and capillary blood.

Animals↗
PubMed1989

A controlled trial of sip-feed supplements in elderly orthopaedic patients.

The potential nutritional and clinical benefits of sip-feed supplements were investigated by means of a controlled trial in elderly female patients admitted for orthopaedic surgery. A nutritional risk assessment procedure (Nutritional Risk Questionnaire, NRQ) was used to identify patients who might benefit from supplementation. Patients identified as high risk who did not receive supplements showed significant losses in triceps skinfold thickness (TSF) and mid-upper arm muscle circumference (MUAMC) measurements during hospitalization. Such changes were not observed in high-risk supplemented patients, but significant losses of MUAMC were also recorded in a group of patients who failed to comply with the supplement. No differences in biochemical parameters, muscle function, or clinical outcome were observed between supplemented and unsupplemented and non-compliant patients. The problems of poor compliance to sip-feed supplements and failure to observe clinical benefit in supplemented patients are discussed.

Aged↗