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Biomedical subjects

H Guerra

Publications and source records attributed to H Guerra.

34 records · Page 2Linked to original sources
PubMed1983

A selective liquid medium for primary isolation of South American Leishmanias.

A selective liquid medium for direct isolation of Leishmania spp. from mucocutaneous lesions is described. Minimal inhibitory concentrations and synergy studies were performed and used to select 5-fluorocytosine as an antimycotic agent which inhibits contaminating fungi without an adverse effect on the parasite thus permitting its isolation from contaminated lesions. Penicillin-Streptomycin were included as antibacterial agents. Isolations have been obtained from biopsy material in an average of 5.6 days from 11 of 15 patients with mucous lesions.

Animals↗
PubMed1982

Single dose treatment with praziquantel (Cesol R, EmBay 8440) of human cestodiasis caused by Diphyllobothrium pacificum.

Diphyllobothrium pacificum, a large tapeworm of seals, is often found as an accidental parasite of man in Perú. The main symptoms is causes are abdominal pain, meteorismus and flatulence, and diarrhea. We report the results of 32 single-dose (10 mg/kg weight) treatments with Praziquantel (Cesol R, EmBay 8440) in 31 patients. One of these patients was shown to be cured but presented a reinfection 270 days later, and required retreatment. Praziquantel was effective in all cases. All patients were clinically cured. No ova were found in stool examinations at 30, 60, and 90 days after treatment, while pretreatment stools were positive for ova with all the techniques used. The antiparasitic effect was evident in 11 cases which segments of the tapeworm were eliminated within the first 3 days of treatment: the fragments were all partially digested or autolysed. A treatment scheme incorporating a purge may be best, to recover the parasite in its entirety and thus ascertain cure with no repeated controls.

Adolescent↗
PubMed1973

Infection at the subcellular level. II. Distribution and fate of intravenously injected brucellae within phagocytic cells of guinea pigs.

Cells of Brucella melitensis strain 16 M were labeled with (32)P. When injected into normal guinea pigs, labeled, viable bacteria were taken up and inactivated in liver and spleen during the 60 min after infection. Both uptake and inactivation increased if brucellae were coated with antibrucella antibody. Neither viability nor radioactivity were lost when labeled brucellae were incubated for 60 min in vitro with normal guinea pig blood, liver homogenates, or in defined medium. Incubation for 12 h with antibrucella rabbit immunoglobulin G similarly was innocuous. Livers were removed from infected animals at various times up to 60 min after injection and were separated into subcellular fractions. The numbers of total (determined by radioactivity measurements) and viable brucellae as well as the acid phosphatase activity in the various fractions were determined. Total bacteria and acid phosphatase activity were progressively transferred from the mitochondrial plus light mitochondrial (M + L) fraction to the nuclear (N) fraction. Viability of brucellae declined more rapidly in the N fraction than in other fractions. Examination of M + L fractions by isopycnic centrifugation showed a decrease in viability of both free brucellae and those in particles. The results indicated the formation of bacteria-containing heterolysosomes which progressively increased in size and in which brucellae were inactivated. The antibrucella activity of phagocytes of guinea pig liver in vivo appeared to be greater than that of peritoneal macrophages from immune rabbits or of bovine leukocytes studied in vitro.

Acid Phosphatase↗
PubMed1972

Infection at the subcellular level. I. Localization of intravenously injected brucellae in the vacuolar apparatus of cells of guinea pig liver.

The distribution of Brucella melitensis in various tissues and in subcellular fractions obtained from liver was investigated to evaluate the initial phases of brucellosis in the guinea pig. Fifty minutes after intravenous infection, brucellae were found principally in the blood and liver, with a substantial number recovered from spleen. Fractionation of liver established that most bacteria were found in the mitochondrial plus lysosomal (M + L) fraction; a significant number, however, sedimented in the nuclear (N) fraction. With time, there was a progressive shift of bacteria from the M + L to the N fraction, accompanied by a similar shift in acid phosphatase activities. Isopycnic centrifugation of mixtures of M + L fractions and brucellae permitted complete separation of acid phosphatase-bearing particles from bacteria. Similar experiments with fractions from infected animals showed that viable bacteria were found in both the acid phosphatase and free brucellae regions of the gradient. At 10 min postinfection, 52% of the recovered organisms were in the acid phosphatase region; at 30 min, 65%; at 60 min, 85%; and at 315 min, 79%. Detergent plus sonic treatment of an M + L fraction from the liver of an animal killed 50 min after infection caused most of the bacteria in the acid phosphatase region to shift to the region where free bacteria were found. These data suggested that brucellae sequestered in the liver were located primarily in the vacuolar apparatus of the cells which phagocytized them.

Acid Phosphatase↗
PubMedDate not supplied

Natural Leishmania infection of Lutzomyia spp. in Peru.

Natural infection of Lutzomyia spp. with Leishmania was studied with the aid of the polymerase chain reaction (PCR) in Chaute, Lima, Perú, a locality endemic for Andean cutaneous leishmaniasis (uta). The PCR, with primers specific for the L. braziliensis complex, was applied to sandfly pools. Sandflies were sampled from April 1990 to May 1991 with CDC light traps in homes, and from near homes with a Shannon trap using protected human bait. Lu. verrucarum (4 pools) and Lu. peruenis (2 pools) from the anthropophilic collections, and Lu. verrucarum (2 pools) from indoors were found to be infected with Leishmania. The majority of infected sandflies were recorded mainly in April 1991 (4 pools), coinciding with the highest sandfly densities and the maximum number of new cases of uta (7). Non-infected sandflies were found from May to October 1990 and January to March 1991. Thus, these 2 sandfly species play a role in the spread of leishmaniasis among humans and other animals in Chaute.

Animals↗
PubMedDate not supplied

Assessing the viability of Mycobacterium leprae by the fluorescein diacetate/ethidium bromide staining technique.

In the present study we have evaluated the Fluorescein Diacetate/Ethidium Bromide (FDA/EB) staining technique to assess the viability of Mycobacterium leprae obtained from biopsies of leprosy patients under different periods of treatment. Bacillary suspensions were obtained from skin punch biopsies and stained with the FDA/EB solution. The average percentage of green cells seen which were deemed to be viable were: 67.2% of green cells in patients without previous treatment; 45.6% in patients with 1 to 6 months of treatment; 25.9% for patients with 7 to 12 months of treatment and 10.5% in patients with 13 to 24 months of treatment. All the patients studied were on multidrug therapy. The differences obtained in the percentages of green cells in the different groups of patients were statistically significant as determined by the Wilcoxon's test. The decrease in the percentage of green cells observed with increasing periods of treatment suggests that the FDA/EB technique correlates with the actual viability of M. leprae. The application of this technique in the routine procedures performed with Hansen's disease patients could be very useful for monitoring the effectiveness of treatment in leprosy patients.

Ethidium↗
PubMedDate not supplied

Leishmaniasis in the lowlands of Bolivia, prevalence of the disease in two groups of localities with different settlement ages in Carrasco Tropical, Cochabamba.

The invasion of the Bolivian Jungle has brought the new colonists some unfamiliar diseases, among which we study Leishmaniasis. A previous study described the situation in Yapacaní. Departamento of Santa Cruz, a primary rain forest lowland area. We now focus on the characteristics of Carrasco Tropical, close to a hilly territory of the andean mountains. We studied 11 localities ("colonies") grouped as unions with different lengths of residence in the area. We considered males and females over 15 years old as "at risk" and studied in them all forms of leishmanial infection, through clinical and laboratory (smears) means, including the Montenegro Skin Test (IDRM). Cutaneous ulcers and scars were seen in 2.9% (10 patients of 339 at risk, 6 from "27 de octubre", a younger settlement, 4 from the older Tamboradas): mucocutaneous lesions in 3 (1 from the younger settlement); and skin scars alone in 10.3% (35 from the younger area). The only 2 females with positive findings in the study were seen in this latter group. Transmission is apparently associated with the primary forest which exists at the foot of the Andes in the area, which is visited preferentially by young men.

Adolescent↗
PubMedDate not supplied

[Research in tropical medicine and primary health care in Peru].

Tropical medicine's fundamental task is to improve health in the tropics. By adopting primary health care strategies, it satisfies the real needs of the population while doing research, improving its effectiveness and social impact. We illustrate this with some examples drawn from our experience, where this potentiation is evident. A sanitary dermatology study, based on health auxiliaries and promoters, encompassed a whole jungle province, with 68,977 km2 and 103,681 inhabitants. It resulted in an excellent relationship with the populations, and findings of significance for early diagnosis and control of hanseniasis and other diseases. It also facilitated an extension of activities to include the entire Amazonian Region, with specific concentration on training of the health personnel. Clinico-epidemiological studies on leishmaniasis in Andean valleys incorporated activities of sanitary education, health care, aspects of community development, etc., and extended into other geographic areas. Migrant workers from high-altitude communities in Cusco who have been to the jungle and acquired cutaneous or mucocutaneous leishmaniasis formed Patient Associations. The latter now receive support for their health and development needs from health authorities and many institutions; our Institute contributes with improved therapeutic procedures and further epidemiologic studies to orient preventive and control measures.

Humans↗