Sidney Klaus

Permethrin resistance in the head louse Pediculus capitis from Israel

Head lice, Pediculus capitis, were collected from children aged 3–12 years in Maale Adumin, a town near Jerusalem, after reports of control failure with the pyrethroid insecticide permethrin. A total of 1516 children were examined: living lice and eggs were found on 12.1% of the children; or another 22.8% of the children only nits were found. Twice as many girls as boys (8.1% v 4%) were infested with lice and or nits. Head lice collected from infested children were exposed to permethrin impregnated filter‐papers. Log time probit mortality (ltp) regression lines were calculated for mortality data and compared to ltp lines for a similar collection of head lice made in 1989. The regression lines for the two years were significantly different, with a 4‐fold decrease in susceptibility at the LT50 level between 1989 and 1994. The slopes of the lines also suggested that the 1994 population was more heterogenous in its response to permethrin than the 1989 population. In contrast, a laboratory population of body lice (Pediculus humanus) tested with the same batch of permethrin‐impregnated papers showed a slight but non‐significant increase in susceptibility between 1989 and 1994. The results suggest that resistance to pyrethroids has developed rapidly among head lice since permethrin was introduced in 1991 as a pediculicide in Israel.

Epidemiology of cutaneous leishmaniasis

Leishmaniasis refers to an infection caused by protozoan parasites of the genus Leishmania. Of the three clinical expressions of the disease—cutaneous, visceral, and mucocutaneous—the cutaneous form (CL) is the most abundant. It is important to recognize that CL does not refer to a single disease. At least 12 species of the genus Leishmania are known to cause CL, and each parasite species has its own characteristic vectors and reservoirs. Bradley has pointed out that in no other parasitic genus infecting man is there such a “diversity of species and strains, variety of pathogenic manifestations, and ecologic richness of transmission patterns.”1 It is now clear that only by recognizing the complexity of this group of diseases—including the intricate patterns of interaction between hosts, reservoirs, and vectors—can progress be made in formulating effective methods of control.

Melanocyte autologous grafting for treatment of leukoderma

Patients with three types of leukoderma--vitiligo, idiopathic guttate hypomelanosis, and postinflammatory leukoderma--had successful repigmentation after transplantation of autologous melanocytes. The procedure was performed easily by producing blisters on normal skin and on depigmented lesions. Blisters were produced by suction or by freezing with liquid nitrogen. The roof of the blister from donor skin was grafted to the raw surface of the recipient site. Repigmentation was visible within 7 to 14 days. Direct immunofluorescence staining with bullous pemphigoid antibodies suggested that the separation of the epidermis from the dermis occurs within the lamina lucida. Histochemical studies confirmed the absence of dopa-positive cells in the areas of leukoderma prior to grafting. Melanocytes were present in the successful grafts.

Clinical observations related to head lice infestation

Living lice and eggs were found in 19% of 2643 children examined in Israel. Boys and girls were equally infested. Bite reactions, pruritus, excoriations, lymphadenopathy, and conjunctivitis were the most common signs and symptoms. Bite reactions, pruritus, excoriations, and conjunctivitis were found more frequently in infested children than in noninfested children. Lymphadenopathy, eczema, influenza, herpes, crusts behind ears, blepharitis, seborrhea, psoriasis, erythema, vitiligo, secondary infections, and scars were equally common in both groups. The sequence of the skin reactions of a volunteer to continuous exposure to lice bites was as follow: phase I, no clinical symptoms; phase II, papules accompanied by pruritus of medium intensity; phase III, wheal formation immediately after the bite, followed by a delayed papular reaction and intense itching; phase IV, papular reaction with diminished reactivity of the skin and mild pruritus. Healed bite reactions reappeared when other parts of the skin were again exposed to the lice.

Epidemiological studies on head lice infestation in Israel. I. Parasitological examination of children.

ABSTRACT: Of 3,079 children in a medium‐sized community near Jerusalem, 11.2% were found to be infested with living lice and eggs and another 23.4% had only nits. Boys and girls were equally infested. The incidence of infestation was highest among children4–11 years of age. About 78% of the infested children had from one to ten lice. Approximately 80% of the infested children had nits that were 2–5cm away from the scalp. Boys with medium length hair and girls with short hair showed the highest incidence of lice infestation. Children with brown and red hair were more infested than those with black and blond hair. Boys and girls with straight and wavy hair were more infested than those with curly and frizzy hair.

Cutaneous Leishmaniasis Acquired During Military Service in the Middle East

BACKGROUND Cutaneous leishmaniasis is endemic in much of the Middle East. Personnel from more than 55 nations are currently participating in Middle East peacekeeping and military activities. OBSERVATIONS Twenty-three Fijian members of a military observational force in Sinai, Egypt, acquired cutaneous leishmaniasis. They were treated successfully with 1-month courses of ketoconazole. CONCLUSIONS Soldiers who acquire cutaneous leishmaniasis may return home to nations where cutaneous leishmaniasis is unknown or rarely diagnosed. Cutaneous leishmaniasis, caused by Leishmania major, may be treated with ketoconazole rather than antimonials.

Changing patterns of cutaneous leishmaniasis in Israel and neighbouring territories

The most frequent form of cutaneous leishmaniasis (CL) in Israel and the neighbouring territories is due to Leishmania major, which is endemic mainly in the Jordan Valley and in the Rift Valley. CL due to L. tropica is much less common, and in the past only sporadic cases have been reported. In this study we present data obtained during the years 1988-1992 regarding CL in the area. Our clinic has diagnosed a total of 371 leishmaniasis cases, most of whom acquired the infection in the Jordan Valley, mainly during June and July. About one-third of the patients had single lesions, and one-third more than 5 lesions. We also describe an outbreak of leishmaniasis in Kfar Adumim, a village 15 km east of Jerusalem, where leishmaniasis was previously unknown. Parasites were characterized by the polymerase chain reaction and by immunostaining, and found to be both L. tropica and L. major. The localization of the homes of the affected people on a slope where hyraxes were abundant suggests that these animals might have been involved in the transmission of L. tropica in this area.

Efficacious topical treatment for human cutaneous leishmaniasis with ethanolic lipid amphotericin B

Old World cutaneous leishmaniasis (CL) is a widespread and potentially disfiguring protozoa1 infection, caused by the infection of dermal macrophages with Leishmania parasites. Despite the various implemented measures to prevent the disease, there is a steady number of infected individuals who seek treatment. Systemic treatments available are very often unjustified owing to their toxicity (e.g., pentavalent antimonials) or to their variable efficacy (e.g., ketoconazole). Topical treatment, the obvious way to treat a localized skin disease, still poses a challenge. Paromomycin-containing preparations have proven effective in some cases (El-On et al., 1985), but not in others (KLAUS et al., 1994; BEN SALAH et al., 1995), and often cause substantial skin irritation. Amphotericin B (AmB), a potent antileishmanial antibiotic, has not been previously delivered topically to dermal lesions. We have recently reported preliminary results showing that a colloidal dispersion of AmB and cholesteryl sulphate, in the presence of 5% ethanol and in the absence of glucose, has significant therapeutic effect in the treatment of CL lesions. The presence of glucose, on the other hand, inhibited the therapeutic effect (VARDY et al., 1999). Here we present results obtained in 1999-2000 on the treatment of 17 patients with AmB, in a prospective placebo-controlled study. Each patient had at least 1 placebo-treated and 1 AmB-treated lesion.

Efficacious Topical Treatment for Murine Cutaneous Leishmaniasis with Ethanolic Formulations of Amphotericin B

ABSTRACT The goal of the present study was to evaluate the antileishmanial effects of topically applied lipid-based formulations containing amphotericin B (AmB) in CBA mice as a model for human cutaneous leishmaniasis. Such treatment, if efficacious, is expected to be superior to systemic treatments since, by acting in a localized manner, it will require lower, and therefore less toxic, drug dosages. Three preparations of AmB complexed to polar lipids were tested: Fungizone (mixed micelles composed of AmB and deoxycholate), Amphocil (AmB and cholesteryl sulfate complex), and ABPLC (AmB and phospholipid complex). All these formulations killed parasites in vitro with similar efficacies but were ineffective when they were applied topically. However, Amphocil and ABPLC, but not Fungizone, when dispersed in an aqueous solution containing 5 to 25% ethanol, induced a statistically significant improvement in lesion size from week 2 or 3 onward (a total of 15 mg of AmB per kg of body weight was applied over 3 weeks). AmB biodistribution measurements following topical application of Amphocil, determined by high-pressure liquid chromatography, showed that AmB was detectable in the skin but not in the internal organs. Application of at least 10 times more drug was necessary to obtain detectable levels of AmB in the internal organs. After application of therapeutic doses of ABPLC, very low levels of AmB were detected in the internal organs. These experiments show for the first time that AmB administered topically as a complex either with cholesteryl sulfate or with phospholipids and in the presence of ethanol can penetrate the skin and kill sensitive organisms in a localized manner by using very low total drug concentrations.

Methods for in Vivo Tissue Electroporation Using Surface Electrodes

AbstractElectroporation of tissues has many potential biomedical applications, including transdermal and targeted drug delivery. Although there are established protocols for electroporation of single cells, electroporation of tissues remains largely unexplored. Here we describe methods for in vivo tissue electroporation with surface electrodes, where either (a) molecules are provided at the outer surface of skin and electroporation is caused in order to transport molecules across the skin or (b) molecules are injected into an animal and internal tissue cells are electroporated to enhance up-take of the injected molecules. Factors considered in our experimental design include selection of electrode material and electrode/tissue geometry. Electrode materials were used which could accommodate a high instantaneous current density and were expected not to form harmful electrochemical products. Due to the complex heterogeneous nature of tissues, the choice of electrical pulse parameters was guided by, but not b...