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Biomedical subjects

D G Godfrey

Publications and source records attributed to D G Godfrey.

At least 19 recordsLinked to original sources
PubMed2000

Baerveldt drainage implants in eyes with a preexisting scleral buckle.

OBJECTIVE: To describe the surgical insertion of a Baerveldt drainage implant and postoperative visual acuity and intraocular pressure (IOP) outcomes in patients with a preexisting scleral buckle. METHODS: Medical records of all patients with a preexisting scleral buckle who underwent insertion of a Baerveldt drainage implant at Bascom Palmer Eye Institute, Miami, Fla, from January 1, 1994, through December 31, 1998, were reviewed. Outcome measures included visual acuity and IOP at 1 year. RESULTS: At 1 year postoperatively, 14 (88%) of 16 patients had stable or improved visual acuity. Preoperatively, mean IOP was 30.9 mm Hg and the mean number of antiglaucoma medications was 3.4; at 1 year postoperatively, mean IOP was 12.0 mm Hg and the mean number of antiglaucoma medications was 0.8 (P<.001). Nine patients (56%) achieved an IOP of greater than 5 and no greater than 21 mm Hg without medication, and an additional 7 (44%) achieved this level of IOP control with medication. No patient required further surgery for uncontrolled IOP during the follow-up interval, which ranged from 19. 1 to 45.5 months. CONCLUSION: Baerveldt drainage device insertion behind or over a preexisting encircling band is often successful in managing refractory glaucoma in patients who have undergone previous scleral buckling procedures. Arch Ophthalmol. 2000;118:1509-1513

Adolescent↗
PubMed1999

Transpupillary thermotherapy for small choroidal melanoma.

PURPOSE: To report the treatment of small choroidal melanoma with transpupillary thermotherapy. METHODS: We examined a nonrandomized and uncontrolled series of 14 eyes of 14 patients who were followed up with serial ophthalmoscopy, ultrasonography, and photography. Transpupillary thermotherapy was performed upon documented evidence of tumor growth. RESULTS: After transpupillary thermotherapy, mean follow-up +/- SD was 16 +/- 6.41 months (range, 7 to 28 months) with 10 eyes followed up for at least 1 year. The mean preoperative tumor height was 1.79 +/- 0.59 mm (range, 0.78 to 2.60 mm). Six months after treatment, the mean height was 0.54 mm +/- 0.57 mm (range, 0.00 to 1.16 mm). In 10 eyes, the treated lesion flattened entirely with a mean interval between treatment and flattening of 8.7 months (range, 3 to 21 months). Three patients required retreatment for lack of regression or recurrent growth. The average time to retreatment was 11 months (range, 5 to 15 months). No eye was retreated more than once. There were three amelanotic lesions, all treated in a single session without recurrence. Complications consisted of retinal hemorrhage, retinal vascular occlusion, retinal traction, exudative serous neurosensory detachment, vitreitis, and postoperative pain. The sole treatment failure occurred in an eye treated with a juxtapapillary tumor, with recurrence developing from a previously flattened lesion. This eye was enucleated 10 months after the single initial treatment. At the time of writing, there had been no tumor-related death. CONCLUSIONS: Transpupillary thermotherapy may represent a viable treatment alternative for both pigmented and amelanotic small choroidal melanoma. Diligent follow-up is axiomatic because retreatment may be necessary. Recurrent tumors may develop from flat lesions. Juxtapapillary tumors may be at higher risk for recurrence. Definitive statements regarding the role of transpupillary thermotherapy in the management of small choroidal melanoma await 5-year and 10-year morbidity and mortality data.

Adult↗
PubMed1998

Epibulbar allergic granulomatous nodules in a human immunodeficiency virus-positive patient.

PURPOSE: To report an unusual epibulbar inflammatory process in a patient with human immunodeficiency virus (HIV). METHODS: Case report. A 32-year-old man developed fleshy epibulbar nodules on his right conjunctiva and cornea after being treated for conjunctivitis. A biopsy of the lesions was done, and the specimen was processed for histopathologic examination. RESULTS: The biopsy specimen contained inflammatory cells, including an eosinophilic abscess. The diagnosis was allergic granulomatous nodules. CONCLUSION: This case illustrates the occurrence of epibulbar allergic granulomatous nodules in an HIV-positive patient.

Adult↗
PubMed1994

The persistence of genetic homogeneity among Trypanosoma brucei rhodesiense isolates from patients in north-west Tanzania.

Trypanosomes isolated during 1991 from nine patients with Rhodesian sleeping sickness in north-west Tanzania were genetically characterized by electrophoresis of ten enzymes. Eight isolates were allocated to a known zymodeme (Z306); another had an enzyme profile (Z379) not previously encountered. An example of Z306 has been previously isolated in 1971, nearby in a part of Rwanda adjacent to the border with Tanzania; in addition, a closely related isolate, in Z307, was collected in 1959 from a patient in north-west Tanzania. The new zymodeme (Z379) was 94% similar to Z306, and both had a close similarity of 89% to Z307. All these isolates belonged to the zambezi strain group of related zymodemes, and evidence is presented that other examples of the group have been collected from man in Tanzania since 1959. Such apparent long term genetic stability is similar to circumstances further south in an endemic area of Zambia, where 12 examples of Z306 and two of Z307 were acquired over a period of 12 years from patients. The similar genetic homogeneity among trypanosomes in endemic parts of both Tanzania and Zambia contrasted markedly with the heterogeneity described to the north of Tanzania in that different strain groups circulate in epidemic areas of Kenya and Uganda.

Animals↗
PubMed1992

Numerical taxonomy of Trypanozoon based on polymorphisms in a reduced range of enzymes.

Numerical analyses of Trypanozoon taxonomy are presented, based on the isoenzyme data of Stevens et al. (1992). The previous study used a reduced range of enzymes compared with earlier work; the analyses indicate the value of this rationalized system. Both recently isolated trypanosome stocks and previously studied populations were included, allowing detailed comparison with earlier studies. Relationships between zymodemes were calculated with an improved similarity coefficient program, using Jaccard's coefficient (1908), and by Nei's method (1972). Dendrograms were constructed from the matrices produced with the group-average method. The groupings produced by both numerical methods were in close agreement, and the clusters of related principal zymodemes largely matched the species, subspecies and strain groups proposed by previous workers. Trypanozoon biochemical taxonomy is reviewed and the groupings reinforced by this study are: the mainly East African strain groups, busoga, zambezi, kakumbi, kiboko and sindo; T.b. gambiense and the bouaflé strain group from West Africa, and T. evansi; an intermediate bouaflé/busoga group was also recognized.

Africa, Eastern↗
PubMed1991

Elusive trypanosomes.

Professor Kershaw's encouragement of the development of anion-exchange separation of African trypanosomes from blood led to two decades of activity when, for the first time, considerable progress was made in the intrinsic characterization of these parasites. Such characterization depended on establishing high infections in laboratory rodents. However, the collection of samples from the field was restricted by the failure of certain trypanosomes either to infect, or to multiply adequately in, rodents. More recently, in vitro culture has come to play an increasingly important role in producing material. By obtaining procyclic forms directly from wild tsetse flies, or by transforming low numbers of bloodstream forms in field samples to the procyclic phase in experimental tsetse, trypanosomes of poor or nil infectivity to rodents were readily cultured in the large amounts required for biochemical characterization. A number of specimens of a new kind of Nannomonas, of Trypanosoma simiae, of T. grayi, and of an antigenically distinct T. brucei gambiense were found. Evidence is presented that many other kinds of trypanosome may be eluding isolation by their inability to infect rodents.

Animals↗
PubMed1988

Trypanosoma congolense: the distribution of enzymic variants in east and west Africa.

A total of 114 stocks of Trypanosoma congolense originating from Kenya, Uganda, Tanzania, Zambia and Sudan, but including, for comparison, stocks from The Gambia, Liberia, Ivory Coast, Nigeria and Cameroun, were compared by isoenzyme electrophoresis for 6 enzymes. The zymodemes were grouped, both from a dendrogram and using a cladistic method, after calculating the dissimilarity, or distance, between profiles. Previous observations are broadly confirmed, the zymodemes clustering separately according to geographical origin and ecological zone. Thus, one group was composed almost entirely of East African stocks, and another of stocks from both East and West Africa, although each group was of savanna origin. A third group was composed of stocks from the humid, rain-forest zones of West Africa, and was particularly characterized by isoenzyme variants of superoxide dismutase and glucose-phosphate isomerase. Two stocks from the Kenyan coast formed a markedly separate group, which may be taxonomically distinct.

Africa, Eastern↗
PubMed1987

Isoenzyme changes during the life cycle of Trypanosoma cruzi.

The isoenzyme profiles, for 14 enzymes, of amastigotes, trypomastigotes and epimastigotes were compared in various cloned and uncloned T. cruzi stocks belonging to different zymodemes. A culture method with a human diploid cell line was developed and produced either pure amastigotes or trypomastigotes in high yields. Trypomastigotes were also isolated from rat blood and from liquid culture. Epimastigotes were harvested from various acellular media and from the overlay of cell monolayers. The isoenzyme patterns of each life-cycle stage showed consistent differences in the number, position and intensity of the electrophoretic bands for certain enzymes. With the single exception of one peptidase, the variable patterns were stage-specific regardless of whether the organisms were harvested from animals or from various cultures at different temperatures.

Animals↗
PubMed1987

Enzyme polymorphism and the identity of Trypanosoma brucei gambiense.

Thirty-two isolates from man in known areas of Gambian trypanosomiasis, in the Sudan, Kenya, Zaire, Nigeria, Ivory Coast, Burkina Faso, Liberia and Senegal, were examined by isoenzyme electrophoresis of 11 enzymes. Comparisons were also made with our previously published results on 23 other stocks of similar origins, which had been examined in the same manner. All those stocks of low initial virulence to laboratory rodents, which thus conform to the accepted view of the behaviour of Trypanosoma brucei gambiense can be identified by characteristic combinations of enzyme patterns, especially certain aminotransferase markers. A limited study of superoxide dismutase polymorphism suggested a further marker of value. The isolates of high initial virulence to rodents, which are thus behaviourally akin to T. b. rhodesiense, did not share these characteristics. We conclude that there exists a homogeneous group of trypanosomes of wide dispersion throughout tropical Africa, characterized by certain isoenzyme combinations and low initial virulence to rodents, which corresponds to the classical concept of T. b. gambiense. The features of limited antigenic repertoire, high resistance to normal human serum and restriction fragment length polymorphisms of the genes for certain variant surface glycoproteins also appear to be characteristic of this group.

Africa↗
PubMed1986

Effects of dietary supplementation on autoimmunity in the MRL/lpr mouse: a preliminary investigation.

The effects of dietary fatty acid supplementation on various disease parameters in the spontaneously autoimmune MRL-mp-lpr/lpr mouse model of systemic lupus erythematosus before onset of disease were investigated. A fat deficient diet was supplemented with the following oils: olive oil, sunflower oil, evening primrose oil (EPO), fish oil, and a fish oil/EPO mixture. The mice receiving a diet enriched with EPO showed an increase in survival, as did those receiving the fish oil/EPO mixture. These results, taken together with those of the other parameters monitored, suggest that EPO may be of benefit in alleviating the murine form of the disease.

Animals↗
PubMed1983

The sheep as a potential reservoir of human trypanosomiasis in the Republic of the Congo.

The identical electrophoretic isoenzyme patterns of a human-plasma-resistant Trypanozoon stock from a sheep and of two other stocks from trypanosomiasis patients in the Congo Republic indicated that the sheep stock was probably infective to man. These, and one further human stock from the Congo, closely resembled stocks isolated from man in Liberia and Ivory Coast.

Animals↗
PubMed1983

Enzyme polymorphism and the distribution of Trypanosoma congolense isolates.

Conditions were established for demonstrating, by electrophoresis, polymorphism in 12 soluble enzymes from Trypanosoma congolense. Three enzymes had identical mobilities in every stock, variation occurring among the remaining nine. Enzyme profiles were determined in 78 stocks collected from various hosts in a number of African countries, and were used by the computer to establish relationships within the collection. The major groupings formed solely from the isoenzymes corresponded remarkably closely to the origins of the stocks. Two distinct enzymic divisions formed, related only at the 20% level; Division A consisted entirely of stocks isolated in the humid coastal areas of West Africa, while Division B consisted mostly of stocks from drier zones throughout Africa. Some large groupings within these two main divisions also correlated with particular areas of origin within the major ecologic zones. The dry zone Division B included one group almost exclusively from East Africa, and two quite distinct enzymic groups from The Gambia; isolates from Liberia and Ivory Coast tended to fall into separate groups within the humid zone Division A. It is suggested that the differences between the major divisions may be associated with infraspecific adaptation to the different vector species occupying the separate habitats.

Africa↗
PubMed1982

Epidemiological studies on the animal reservoir of Gambiense sleeping sickness. Part III. Characterization of trypanozoon stocks by isoenzymes and sensitivity to human serum.

Polymorphism in 12 enzymes, as shown by electrophoresis on thin-layer starch-gel, was examined in 88 stocks of trypanosomes of the subgenus Trypanozoon isolated from man and animals in the Ivory Coast and Upper Volta. Three of the enzyme profiles seen in trypanosomes from man in the Ivory Coast were exactly the same as in trypanosomes from local domestic pigs and from various game animals and a bovine in the Upper volta, thus confirming previous evidence that human trypanosomiasis is a zoonosis in West Africa. Altogether 9 zymodemes were found in man; one was exactly the same as another from the Congo while a further one was identical to a Ugandan zymodeme. Thirty-one zymodemes were found only in animals, and 6 were exactly the same as others from elsewhere in Africa, including the eastern part. All zymodemes resembled each other by possessing common electrophoretic patterns in 5 enzymes. In most zymodemes, the variants of two other enzymes were characteristically West African, although an East African influence was apparent, together with further evidence of hybridization. Many zymodemes differed from others only to a minor extent in a few isoenzyme bands. A group of closely related minor zymodemes constituted another trypanosome population ineffective to man in West Africa which had a variable sensitivity to normal human serum; enzymatically it was clearly separated from the major zymodeme previously described in West Africa, which was consistently resistant to normal human serum and had been previously associated with chronic gambiense sleeping sickness.

Africa, Western↗
PubMed1980

Epidemiological aspects of three Trypanosoma cruzi zymodemes in Bahia State, Brazil.

Culture forms of 104 stocks of Trypanosoma cruzi isolated in different regions of the State of Bahia were compared by electrophoresis of six enzymes. The three distinct combinations of isoenzyme patterns seen were designated ZI, Z2 and Z3. In an area of endemic Chagas's disease in eastern Bahia, T. cruzi Z1 was associated with sylvatic mammals and sylvatic triatomines, whereas T. cruzi Z2 was associated with a separate domestic cycleof transmission. T. cruzi Z1 was also found in sylvatic triatomines from other parts of the State. In contrast, in an area of the São Francisco Valley region of western Bahia, both T. cruzi Z1 and Z2 were isolated from man, domestic animals, and peridomestic rats. T. cruzi Z3 was isolated from an armadillo and from Panstrongylus geniculatus, a triatomine commonly found in armadillo burrows. Both T. cruzi Z1 and Z2 appeared to be pathogenic in man: T. cruzi Z1 was isolated from patients with acute Chagas's disease and from a single patient with chronic cardiac manifestations. T. cruzi Z2 was isolated from some asymptomatic individuals but was also associated with acute disease and chronic cardiac and digestive syndromes.

Adult↗