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Biomedical subjects

J el-On

Publications and source records attributed to J el-On.

At least 19 recordsLinked to original sources

An epidemiological survey of Echinococcus granulosus and other helminths in animal populations in northern Israel.

In a survey carried out during the period May 1995 to November 1996, in communities of various ethnic groups in northern Israel, 206 dogs were examined for Echinococcus granulosus and other intestinal helminth parasites by arecoline hydrobromide purges and the coproantigen-ELISA. The arecoline test was performed close to the owners' homes, using plastic sheets secured to the ground. From 56 dogs examined in the Muslim town of Tamra, six (10.7%) were found to be infected with E. granulosus. Four of them also had a mixed infection of Taenia hydatigena and Dipylidium caninum (two dogs), and the remaining two dogs were infected with either D. caninum or Taenia pisiformis. An additional 18 dogs were infected with either T. pisiformis (eight dogs), D. Caninum (seven dogs), or T. hydatigena (three dogs). Two of these dogs harboured mixed infections whereas the remaining 32 dogs were free of helminths. In the Jewish villages, none of the 150 dogs examined were infected with E. granulosus, although 26 (17.3%) were infected with D. caninum, four (2.7%) with Ancylostoma spp. and one (0.7%) with Toxocara canis. Only one of the 22 stray dogs and none of the 15 jackals examined were infected with E. granulosus. However, 21 (95.4%) of the dogs and 12 (80%) of the jackals harboured helminth infections, including: D. caninum (16 dogs and seven jackals), Ancylostoma spp. (five jackals), T. hydatigena (three dogs), and T. canis (one dog). Approximately 18% of the dogs and 33% of the jackals showed mixed infections with two or more of the above helminths. In the abattoirs, 52 (5.9%) of the 874 sheep and 33 (5.3%) of the 616 goats from 17 herds slaughtered in the Muslim and Druze villages were found to be infected with E. granulosus, compared with a 0% infection rate observed in 93 sheep from two herds in Jewish villages.

Animals↗

Persistent diarrhea in a cohort of Israeli Bedouin infants: role of enteric pathogens and family and environmental factors.

This study examined the role of enteric pathogens and infant, family, and household characteristics in persistent diarrhea. Bedouin infants from southern Israel were followed from birth to age 18-23 months. During monthly home visits, stool samples were obtained, and feeding practices and history of diarrhea were determined, and at age 3 months, an environmental assessment was done. Diarrhea surveillance was either via a network covering all community health care facilities or via weekly interviews with the mother. None of the enteric pathogens examined, including Cryptosporidium parvum and enteroaggregative Escherichia coli, were associated with persistent diarrhea. In multivariate analyses, age at first diarrheal illness and maternal age and maternal education were independently and significantly associated with the risk of persistent diarrhea. These data suggest that persistent diarrhea is a clinical entity that may be related less to a specific enteric pathogen and more to the health experiences of children and their home environment.

Animals↗

Detection of Cryptosporidium and Giardia intestinalis in Bedouin children from southern Israel.

During an 18 month period, a total of 4796 stool specimens collected from 151 Bedouin children enrolled in a cohort study and followed from birth, were screened for Giardia intestinalis, Cryptosporidium spp. and other intestinal parasites. Specimens were collected in phenol-alcohol-formalin (PAF) preservative and examined prior to, and after, formalin-ether concentration (FEC). During 6 months of the second year Giardia intestinalis was observed in 17.6% of the specimens and Cryptosporidium in 0.9% as compared with 1.8% (Giardia intestinalis) and 1.6% (Cryptosporidium) observed during the first year. Giardia intestinalis was detected in 8.4% (407/4796) of all the samples examined and Cryptosporidium in 1.3% (63/4796). Other intestinal protozoan parasites and helminthic ova demonstrated in the stool specimens included: Entamoeba coli (0.1%); Entamoeba histolytica (< 0.1%); Hymenolepis nana (0.1%); and Trichuris trichiura (< 0.1%). Mixed infection with 2 parasites was observed in 0.3% of the specimens. PAF fixation was found to be highly effective in preserving the integrity and antigenicity of both Cryptosporidium-oocysts and Giardia intestinalis-cysts. The detection rate of Giardia intestinalis and Cryptosporidium before FEC was not significantly different from that obtained after FEC, showing differences of only 1% and 3% for Giardia intestinalis and Cryptosporidium, respectively.

Animals↗

The development of new foci of echinococcosis in northern Israel: prevalence in domestic animals.

In a survey carried out in 1991-1992 in the town of Yirka in Northern Israel, 49 dogs were examined for Echinococcus granulosus infection and abattoir data, based on organs condemned for the presence of parasites, was collected. The presence of E. granulosus by arecoline test was demonstrated in 7 (14.2%) of the dogs examined, but not parasites were found in the intestines of five stray dogs shot in the area. A survey of sheep slaughtered in the local abattoir during a one-month period revealed Echinococcus cysts in 10% of the 255 animals examined. No Echinococcus parasites were detected in 21 dogs examined 3 months after the initiation of praziquantel treatment. Echinococcosis seems to be a very serious public health problem in Israel and a control programme needs to be given a high priority.

Abattoirs↗

Three- to 7-year follow-up after albendazole treatment of 68 patients with cystic echinococcosis (hydatid disease).

Sixty-eight cystic echinococcosis patients were each treated with 800 mg albendazole/day in four 28-day courses separated by 14-day drug-free intervals. Follow-up for 3-7 years showed that this treatment alone eradicated the cysts in many patients; in most of the remainder, disease progression stopped. Of the 59 patients with liver cyst(s), 41% were cured (all cysts disappeared), 17% showed marked improvement (> 25% contraction, complete consolidation), 24% limited improvement and 15% no change. Of the 12 patients with lung cyst(s), 72% were cured, 9% showed limited improvement and 18% showed no change (18%). No patient worsened but a recurrence occurred in two patients at about 56 months. The times taken to detect an initial cyst change and to detect cure were longer than is generally expected; initial cyst changes and cure could only be detected after 1 year in 12% and 69% of patients with liver cysts and 22% and 37% of those with lung cysts, respectively.

Adolescent↗

Suppression of antigen-specific T cell responses by Leishmania major excreted factor: inhibition of activation signals linked to the T cell antigen receptor and interleukin 2 receptor.

An excreted factor (EF) derived from culture medium of Leishmania major was found to suppress ConA-induced polyclonal activation of mouse T cells. To further dissect the effect of EF on cell-mediated immune responses, we used in vivo primed antigen-specific murine lymph node cells. EF inhibited the proliferative response of keyhole limpet hemocyanin (KLH) or ovalbumin (OA)-primed T cells upon in vitro challenge with the antigen. In addition, it suppressed the induction of interleukin 2 receptor (IL2-R) alpha following mitogen stimulation of unprimed T cells or antigen challenge of KLH-primed T cells. Thus, EF affects early events in signal transduction that follow the T cell antigen receptor (TCR) triggering. To test whether EF may interfere with more remote events in the activation process of T cells, we used IL2-R positive T cells and tested their response to IL2 in the presence of EF. We found that EF inhibited also IL2-dependent T cell proliferation in a dose-dependent manner. The data suggest, therefore, that the locus of inhibitory effect of EF is at both the early and late stages of T cell activation and apparently involves two different signal transduction pathway linked to the receptors for the antigen and IL2.

Animals↗

[Hydatid disease in Israel].

The prevalence pattern of hydatid disease (echinococcosis) in Israel has changed during the past 40 years. Until 1948 it was mainly common in the non-Jewish community; after 1948 its prevalence was high in Jews who immigrated to Israel from Arab countries; and since 1967 endemicity has gradually increased in some rural and semirural Arab and Druze communities. Of 224 surgically-confirmed cases of hydatid disease from these communities during 1960-1989, 52 were from Yirka, a Druze community with a population of 8200. In that town 8% of 63 dogs tested after an arecoline purge and 10% of 255 sheep at the local abattoir were found to be infected. Randomized serosurvey of 758 inhabitants indicated a 1.6% cumulative percentage of hydatid infections, leading to an extrapolated rate of 1583/100,000. Yirka thus is one of the most highly endemic areas for hydatid disease in the world.

Animals↗

Leishmania major: respiratory burst response of infected murine macrophages treated with paromomycin.

The effect of paromomycin sulfate (PR) on the respiratory burst response (RB) of C3H/HeJ mouse peritoneal macrophages infected with Leishmania major, LRC-L137, was studied in vitro. Giemsa staining and acridine orange staining combined with nitro blue tetrazolium (NBT) reduction reaction were used to determine parasite survival and RB response at the level of individual cells. RB response was detected in only 18% of the infected macrophages compared with 60% of the control, uninfected cells. Only 7% of the total RB-responder (NBT-positive) cells showed the presence of intracellular amastigotes. PR at 100 micrograms/ml reduced the number of the infected cells by 85% on the 4th day of cultivation. PR at the same concentration restored 50% of the RB activity of these cells. PR given alone had no effect on the RB of the uninfected macrophages. A similar effect of PR on RB activity was observed with PMA-stimulated macrophages. Both Leishmania-infected and uninfected macrophages treated with PR (100 micrograms/ml) for 4 days retained 50% of their leishmanicidal activity upon reinfection due to drug accumulation within the cells.

Animals↗

Topical treatment of cutaneous leishmaniasis in Belize: in vitro and in vivo studies with Leishmania mexicana.

Strains of Leishmania mexicana isolated from Belizian patients were found to be highly susceptible to paromomycin sulphate (PR) treatment. This drug at 100 micrograms ml-1 destroyed 85-99.5% of in vitro cultivated Leishmania promastigotes within 4 days of exposure to the drug. Leishmania promastigotes inoculated into the base of the tail of Balb/c mice caused the development of local lesions several weeks after infection. These lesions were totally cleared of parasites after 20 days of topical treatment with PR ointment, comprised of 15% paromomycin sulphate and 12% methylbenzethonium chloride in soft white paraffin. Similar results were also obtained with L. braziliensis infections. Isoenzyme analysis was found to be the method of choice for parasite strain identification. Excreted factor serotyping was only partially effective and promastigote agglutination gave negative results.

Administration, Topical↗

Topical treatment of New World cutaneous leishmaniasis in Belize: a clinical study.

BACKGROUND: Many studies have been performed during the past decade to find an effective topical therapy for cutaneous leishmaniasis (CL). OBJECTIVE: Our purpose was to evaluate the effect of paromomycin ointment (P-ointment) containing 15% paromomycin sulfate and 12% methylbenzethonium chloride on Belizean patients with New World CL. METHODS: Fifty-three patients were treated twice daily for 14 to 21 days with P-ointment. RESULTS: Sixty-eight percent of the patients healed, 6% had a delayed cure, and 26% did not respond. No toxic effects from the ointment were observed. CONCLUSION: Topical paromomycin is as efficacious in the treatment of New World CL as other currently accepted modalities that are potentially more toxic.

Administration, Topical↗

Topical treatment of Old World cutaneous leishmaniasis caused by Leishmania major: a double-blind control study.

BACKGROUND: A controlled study of the efficacy of topical paromomycin sulfate (PR) and methylbenzethonium chloride (MBCl) in cutaneous leishmaniasis (CL) has not yet been performed. OBJECTIVE: The therapeutic effect of an ointment containing 15% PR and either 12% or 5% MBCl (15/12 or 15/5 P-ointment) on patients suffering from Old World CL was examined in a randomized, double-blind, cross-over study. METHODS: Thirty-nine patients with Old World CL caused by Leishmania major were treated topically, twice daily, for 10 to 20 days with 15/12 or 15/5 P-ointment and 10 to 20 days with a placebo ointment to achieve a total of 30 days of treatment in all groups. RESULTS: In the P-ointment-treated groups, 74.2% (29 of 39 patients) of the patients were cured versus 26.6% (4 of 15 patients) in the placebo-treated group. Little difference was found between the 15/12 and 15/5 P-ointment groups. CONCLUSION: In most of the patients treated with the active ingredients, total elimination of the parasites was achieved within the first 10 days of treatment.

Administration, Cutaneous↗

Leishmania major: bacterial contamination of cutaneous lesions in experimental animals.

No bacterial contamination has been demonstrated in cutaneous leishmaniasis (CL) nodule and in lesions caused by Leishmania major in Balb/c mice up to 20 days after infection. However, although many phagocytic cells (polymorphonuclear leukocytes and macrophages) were present in the CL lesion, 80% of the lesions showed bacterial contamination that developed within the first 70 days of infection. Topical treatment of the lesion with an ointment containing 15% paromomycin and 12% methylbenzethonium chloride in soft white paraffin for 20 days eliminated all the Leishmania parasites and several of the associated bacteria including: Proteus vulgaris, Pasteurella multocida, Staphylococcus albus and Staphylococcus aureus. This treatment did not affect Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa. Total elimination of these bacteria was achieved only during the healing process, and within 20 days following termination of treatment. The rate of disappearance of bacteria inoculated alone into the base of the tail of normal uninfected Balb/c mice was much faster than that of bacteria inoculated into either the CL nodule or the CL lesion. This study suggests the development of local immunosuppression in the CL lesion that may be mediated by the Leishmania parasites and their metabolites.

Animals↗

High prevalence of human hydatid disease (echinococcosis) in communities in northern Israel: epidemiologic studies in the town of Yirka.

The resurgence of hydatid disease in communities in northern Israel led to epidemiologic studies in 1988 in the town of Yirka, a semirural Druze community of 8200 persons. In domestic animal surveys, 8% of 63 dogs tested after an arecoline purge and 10% of 255 sheep at the abattoir were found to be infected. In a randomized serosurvey of 758 persons using the indirect hemagglutination test (positive titer greater than or equal to 1:512), 9% (68) had a titer greater than or equal to 1:64, 2.2% had a titer greater than or equal to 1:256 and 0.9% had a titer greater than or equal to 1:512. Of those with titers greater than or equal to 1:64, 59 were evaluated by abdominal sonography and chest x-ray: 6 of the 59 were found to be persons who previously had had a liver or a lung hydatid cyst surgically removed; 6 other persons (5 with negative indirect hemagglutination titers) were found to have a newly detected asymptomatic cyst. Of the latter group, hydatid confirmation was subsequently obtained by surgery for 2 persons and by arc 5 and/or immunoblot assay for 4 persons. Thus, the cumulative percentage of confirmed present or recent past hydatid infections was 12/758 (1.6%) leading to an extrapolated rate of 1583/100,000 persons. This ranks Yirka among the highly endemic areas for hydatidosis worldwide. The study also showed that imaging methods were more sensitive than the indirect hemagglutination serologic test for conducting a prevalence survey.

Abattoirs↗

Leishmania major: resistance of promastigotes to paromomycin, and susceptibility of amastigotes to paromomycin-methylbenzethonium chloride ointment.

Cutaneous lesions caused by Leishmania major in BALB/c mice were cured completely when treated topically with an ointment comprising 15% paromomycin sulphate and 1-2% methylbenzethonium chloride ointment in soft white paraffin twice daily for 10 days. No parasites were detected in tissue smears or in cultures from treated cutaneous lesions. Re-developing lesions, considered to be resulting from the migration of parasites from internal organs, showed almost the same response to topical treatment. Promastigotes of the virulent clone 121 of L. major LRC-L137 which were exposed to 100 micrograms ml-1 of paromomycin in RPMI medium at 28 degrees C developed resistance to the drug over 10 passages of exposure. Enzyme analysis of susceptible and resistant promastigotes of this clone showed no differences with regard to their profiles based on 11 enzymes.

Administration, Topical↗

The failure of traditionally used desert plants to act against cutaneous leishmaniasis in experimental animals.

Several desert plants that are traditionally used by the Bedouin community as folkloristic treatment for skin diseases were examined for their efficacy against cutaneous leishmaniasis (CL) in BALB/c mice. Water and chloroform extracts made from these plants were incorporated into cetomacrogol and soft white paraffin respectively and some were supplemented with DMSO. These preparations were applied twice daily for up to 30 days to CL lesions caused by Leishmania major. None of the extracts tested showed any leishmanicidal effect.

Animals↗

Cryptosporidium in Bedouin and Jewish infants and children in southern Israel.

We conducted a 1-year prospective study in two clinics and a hospital in the Negev region of southern Israel to determine the epidemiological and clinical patterns of Cryptosporidium diarrhea among Jewish and Bedouin infants and children living in the same geographical area. A total of 612 episodes were studied: 398 in Bedouins and 214 in Jews, of which 449 occurred in patients with diarrhea and 164 in controls. Cryptosporidium was detected in 13 of 382 patients (3.4%) with diarrhea and in 1 of 138 controls (0.7%) (P = 0.078). In 5 of 13 Cryptosporidium-positive patients (38%) another pathogen was detected. No significant difference in Cryptosporidium detection rates was observed between Jews and Bedouins or between hospitalized or nonhospitalized patients. The frequency of Cryptosporidium detection did not differ significantly when three age-groups were compared (less than 6 months old, 7-12 and 13-36 months old). The rate of Cryptosporidium detection was similar among malnourished and well-nourished patients, as determined by weight-for-height percentiles. Cryptosporidium was detected more frequently during the summer months (8.3%) than during the rest of the year (1.2%) (P less than 0.001). Patients with Cryptosporidium diarrhea did not differ clinically from patients with other causes of diarrhea. However, they were characterized by the absence of fecal leukocytes. Cryptosporidium is not a rare cause of diarrhea in southern Israel. It is more prevalent during the hot and dry season and can be detected in a relatively high prevalence among very young infants. Its clinical features are indistinguishable from those of patients with non-cryptosporidial diarrhea.

Child, Preschool↗