Importance of Follow-Up Microscopic Examination in Hospitalized Patients with Confirmed Scabies.

We investigated the duration of positive microscopic examination in hospitalized patients with confirmed scabies in an acute care hospital. We included hospitalized patients who were diagnosed with scabies between January 2015 and June 2019. From the study period, a total of 31 patients with confirmed scabies were identified. Median age was 75 years. Of a total of 31 patients with confirmed scabies, six were discharged or transferred before getting a negative microscopic test result. Of the remaining 25 patients with negative microscopic test results, the median duration from diagnosis to a negative microscopic test result was 14 days (interquartile range, 9-17). Given that nosocomial outbreaks lead to high workload and considerable resource consumption, adequate treatment, sufficient follow-up examination, and confirmation of cure are warranted before releasing contact isolation.

Concomitant effect of low dose of lindane and intranasal lipopolysaccharide on respiratory system of mice.

Lindane is very commonly used organochlorine pesticide and has been reported to cause several toxic effects including respiratory insufficiency. However, effects of low concentration of lindane alone or in combination with microbial molecules on lungs are not fully understood. To understand the effects a preliminary study was designed on Swiss albino mouse. Male mice were divided into treatment and control group (20; each). Treatment mice were given lindane in ground nut oil orally at 0.25 mg kg-1 day-1 for 60 days. After treatment, 10 mice were challenged with intranasal Escherichia coli lipopolysaccharide (LPS; 80 µg per mice) and remaining 10 with normal saline. The mice were euthanized 16 h post-LPS exposure. Control mice (10 each) were given normal saline or the LPS alone. Mice exposed with lindane and in combination with LPS had increase in total cell counts and leukocyte counts in broncho-alveolar lavage. Histological examination showed lung injury in the lindane-treated mice. The histopathological changes were more pronounced in lindane along with LPS-exposed mice. Lindane alone and in combination with LPS showed expression of immunopositive Toll-like receptor (TLR)-4 and tumour necrosis factor-alpha (TNF-α) positive reaction in various cells of lungs. While LPS induced acute inflammation in the lungs, combination of lindane and LPS exacerbated histological signs of the inflammation. The data indicate that lindane alone or in combination with LPS caused changes in lung morphology and altered TLR-4 and TNF-α expression which may have led to altered response to LPS challenge.

Nail Scabies: An Unusual Presentation Often Overlooked and Mistreated.

Nail scabies is an interesting clinical presentation of scabies. Although it is usually found concomitant with characteristic dermatologic manifestations, it may present as an isolated finding in the immunocompromised host. This condition is commonly mistaken with other diseases such as nail dystrophy, nail psoriasis and onychomycosis. We report two cases of unusual nail presentations that provide clues to diagnosis. Also, literature on unusual nail and dermatologic presentations was reviewed to recognize dermatologist consideration for appropriate treatment options.

γ-Lindane Increases Microcystin Synthesis in Microcystis aeruginosa PCC7806.

HCH factories, and the waste dumpsites associated to its production, have become a global environmental concern, and their runoff could pollute ground and surface waters with high levels of the pollutant. In this study, the influence of lindane (γ-HCH) on microcystin production has been investigated in Microcystis aeruginosa PCC7806. This toxic cyanobacterium is highly tolerant to γ-lindane (20 mg/L), and produces more toxin (microcystin) in the presence of the pollutant. Microcystis degrades γ-lindane and presence of γ-lindane induces genes involved in its own degradation (nirA). RT-PCRsq has been used to monitor changes in levels of transcripts encoded by the mcy operon (mcyD, mcyH and mcyJ), responsible for the microcystin synthesis machinery, as well as other genes involved in its transcriptional regulation, such as ntcA and fur family members. The presence of lindane in the culture media induces mcyD expression, as well as ntcA gene transcription, while other genes, such as mcyH, (putative ABC transporter), are downregulated. The amount of microcystin found in the cells and the culture media is higher when M. aeruginosa is treated with γ-lindane than in control cells. The results suggest that in a lindane polluted environment, Microcystis toxic strains may enhance their microcystin synthesis.

Serie parasitosis en dermatología: pediculosis / Parasitosis in dermatology: pediculosis

La enfermedad producida por Pediculus humanus capitis, conocida como pediculosis, es una parasitosis específica del ser humano de distribución mundial. El contagio puede ser directo por contacto con el cuero cabelludo de una persona afectada, o por fómites contaminados con parásitos, por lo que no distingue raza, sexo, edad ni nivel socioeconómico. Presentamos el caso de una paciente de 80 años con una forma típica de pediculosis. (AU)

The disease caused by Pediculus humanus capitis, known as pediculosis, is a human specific parasitosis. It has a worldwide distribution. Transmission can be by direct contact with the scalp of an affected person or by contaminated fomites with parasites. This infestation makes no distinction of race, sex, age, or socioeconomic status. We present a case of an 80 years old patient with a typical case of pediculosis. (AU)

Treatment of Scabies: Comparison of Lindane 1% vs Permethrin 5.

Scabies, whose etiologic agent is Sarcoptes scabiei, is a neglected parasitic disease that is a major public health problem in many resourcepoor regions. Its current therapies include benzyl benzoate, lindane, permethrin, sulfur, crotamiton, monosulfiram, and oral ivermectin. The aim of this study was to compare the efficacy and safety of lindane 1% lotion vs permethrin 5% in the treatment of scabies. A total of 120 patients with scabies attending a dermatology outpatient department were included. Patients were randomly divided into two groups. Sixty patients and their family contacts received 5% permethrin cream and the other 60 received 1% lindane lotion. Treatment was evaluated at intervals of 2 and 4 weeks. Permethrin provided improvement in 48 patients (80%) after 2 weeks, whereas lindane was effective in only 28 patients (46.6%). Permethrin (5%) cream was found to be significantly more effective in the treatment of scabies compared with lindane in this study. Adverse effects were rare in both the permethrin and lindane groups.

Effect of treatment of cow's urine "Gomutra" and antioxidants in alleviating the lindane-induced oxidative stress in kidney of Swiss mice (Mus musculus).

The study aimed to evaluate the effect of cow urine and combination of antioxidants against lindane induced oxidative stress in Swiss mice. Male healthy mice, 8-10 weeks old, weighing 30 ± 5 g were randomly selected and divided into eight groups, namely, control (C); lindane (L); antioxidant (A), antioxidant+lindane (A+L), cow urine (U), cow urine+lindane (U+L), cow urine+antioxidants (U+A) and cow urine+antioxidants+lindane (U+A+L). Group C animals were administered only the vehicle (olive oil); doses selected for other treatments were: lindane: 40 mg/kg b.w.; antioxidants: 125 mg/kg b.w. (vitamin C: 50 mg/kg b.w., vitamin E: 50 mg/kg b.w., α-lipoic acid: 25 mg/kg b.w.) and cow urine: 0.25 ml/kg b.w. In group A+L and U+L antioxidants and cow urine were administered 1 h prior to lindane administration and in group U+A and U+A+L cow urine was administered 10 min before antioxidants. All treatments were administered orally continuously for 60 days. Lindane treated group showed increased lipid peroxidation, whereas glutathione, glutathione peroxidase, superoxide dismutase, catalase, protein and endogenous levels of vitamin C and E were significantly decreased compared to control. Administration of cow urine and antioxidants alleviated the levels of these biochemical parameters.

Comparison of oral ivermectin vs. lindane lotion 1% for the treatment of scabies.

BACKGROUND: Scabies is a common parasitic infestation that is an important public-health problem in many resource-poor regions. It is commonly treated with the insecticides ivermectin and permethrin. AIM: To compare the efficacy and safety of oral ivermectin vs. lindane lotion 1% for the treatment of scabies. METHODS: In total, 148 patients with scabies were enrolled, and were randomized into two groups: the first group received a single dose of oral ivermectin 200 µg/kg body weight, and the second group were treated with two applications of topical lindane lotion 1%, with a 1-week interval between applications. Treatment was evaluated at intervals of 2 and 4 weeks, and if there was treatment failure at the 2-week follow-up, treatment was repeated. RESULTS: A single dose of ivermectin provided a cure rate of 60.8% at the 2-week follow-up, which increased to 89.1% at the 4-week follow-up. after crossing over to the lindane lotion 1% group. Treatment with two applications of lindane lotion 1%, with a 1-week interval between them, was effective in 47.2% of patients at the 2-week follow-up, which increased to 72.9% at the 4-week follow-up after this treatment was repeated. CONCLUSIONS: A single dose of ivermectin was as effective as two applications of lindane lotion 1% at the 2-week follow-up. After repeat treatment, ivermectin was superior to lindane lotion 1% at the 4-week follow up. The delay in clinical response with ivermectin suggests that it may not be effective against all the stages in the life cycle of the parasite.

Evaluation of micronuclei induction capacity and mutagenicity of organochlorine and organophosphate pesticides.

The genotoxic and mutagenic effects of two commonly used organochlorine pesticides, lindane (LND) and endosulfan (ENS), and two commonly used organophosphate pesticides, chlorpyrifos (CPF) and monocrotophos (MCP) were assessed using in vivo mouse bone marrow micronucleus test and in vitro Ames Salmonella/ microsome mutagenicity test. The results showed that these pesticides alone or in combination, induced significantly high frequency of micronuclei (MN) formation that increased with concentration of pesticides. All these four pesticides produced significant increase in the frequencies of micronucleated-polychromatic erythrocytes (MN-PCE) and decrease infrequencies of PCE in dose-dependent manner. The results indicate the suppression of proliferative activity of the bone marrow and increase in the extent of cell death. ENS and MCP showed mutagenic potential in Salmonella/ microsome assay. ENS induced mutagenic and nontoxic response only in TA98 tester strain of S.typhimurium at the dose of 500 µg/plate and in the absence of metabolic activation. MCP showed weak mutagenic and nontoxic effect only in TA100 tester strain at the dose of 5000 µg/plate in both assays, with or without metabolic activation when compared with negative control. MCP was toxic in TA98 tester strain at the dose of 5000 µg/plate in absence of metabolic activation while reduction in toxicity was seen on addition of S9 mixture. The study clearly showed the genotoxic potential of all these four pesticides and mutagenic response of endosulfan and monocrotophos.

Treatment of scabies: comparison of ivermectin vs. lindane lotion 1%.

Topical antiscabietics have poor compliance. This study aimed at comparing the efficacy and safety of oral ivermectin with topical lindane in treating scabies. In this clinical trial, 248 patients from 2 to 86 years of age were divided into two groups. Oral ivermectin was given to group A in a single dose of 200 µg/kg body weight. Group B received application of lindane lotion 1% twice at one-week interval. When there was no cure in two weeks, 2nd treatment was given with either drug in the respective group. A single dose of ivermectin provided a cure rate of 58.6% at two-week follow up, which increased to 92.7% with 2 doses at the end of 4-week interval. The application of lindane lotion 1% twice at one-week interval was effective in 44.3% of patients at two-week follow up, which increased to 71.7% after repeating the treatment for another two weeks. Single dose application of oral ivermectin was as effective as twice application of lindane lotion 1% at one-week interval. Two doses of ivermectin proved superior to lindane lotion 1% after repeating the treatment at 4-week follow up.

Dynamic changes of α-hexachlorocyclohexane and its enantiomers in various tissues of Japanese Rabbits (Oyctolagus cuniculus) after oral or dermal exposure.

Japanese Rabbits (Oyctolagus cuniculus) were exposed to α-hexachlorocyclohexane (α-HCH) either orally or dermally and concentrations of α-HCH and its two enantiomers were measured at different time intervals in the blood, intestine, liver, kidney, fat, brain, and muscle. The time trends were quantified using toxicokinetic models. It was found that absorption and elimination of α-HCH in blood were first-order processes which can be characterized by a single compartmental kinetic model. The absorption of dermally exposed α-HCH in blood was more than one order of magnitude faster than that of orally exposed α-HCH. The transport of α-HCH from the blood to other tissues was characterized using a two-compartment model. The accumulation rates were different among tissues depending on blood flow rate and fat content. Significant correlation was revealed between α-HCH concentration and fat content for various tissues either before or 1 d after the exposure. However, there was no such correlation at 10 min immediately after the exposure. The enantiomeric fraction (EF) of α-HCH in rabbit blood was nearly racemic before the exposure and increased to 0.73 and 0.82 after oral or dermal exposure, respectively. The result of a toxicokinetic modeling suggested that the strong enantioenrichment of (+)-α-HCH was primarily because the elimination rate of (-)-α-HCH was more than two times higher than that of (+)-α-HCH. The EFs for other tissues also increased dramatically after the exposure and the EFs in brain reached as high as 0.99 due to enantioselective transport across the blood brain barrier.

Dual actions of lindane (γ-hexachlorocyclohexane) on calcium homeostasis and exocytosis in rat PC12 cells.

The persistent organochlorine pesticide lindane is still abundantly found in the environment and in human and animal tissue samples. Lindane induces a wide range of adverse health effects, which are at least partially mediated via the known inhibition of GABA(A) and glycine receptors. Additionally, lindane has been reported to increase the basal intracellular Ca(2+) concentration ([Ca(2+)](i)). As Ca(2+) triggers many cellular processes, including cell death and vesicular neurotransmitter release (exocytosis), we investigated whether lindane affects exocytosis, Ca(2+) homeostasis, production of reactive oxygen species (ROS) and cytotoxicity in neuroendocrine PC12 cells. Amperometric recordings and [Ca(2+)](i) imaging experiments with fura-2 demonstrated that lindane (≥ 10 µM) rapidly increases basal exocytosis and basal [Ca(2+)](i). Additional imaging and electrophysiological recordings revealed that this increase was largely due to a lindane-induced membrane depolarization and subsequent opening of N- and P/Q-type voltage-gated Ca(2+) channels (VGCC). On the other hand, lindane (≥ 3 µM) induced a concentration-dependent but non-specific inhibition of VGCCs, thereby limiting the lindane-induced increase in basal [Ca(2+)](i) and exocytosis. Importantly, the non-specific inhibition of VGCCs also reduced stimulation-evoked exocytosis and Ca(2+) influx. Though lindane exposure concentration-dependently increased ROS production, cell viability was not affected indicating that the used concentrations were not acute cytotoxic. These combined findings indicate that lindane has two, partly counteracting effects. Lindane causes membrane depolarization, thereby increasing basal [Ca(2+)](i) and exocytosis. In parallel, lindane inhibits VGCCs, thereby limiting the basal effects and reducing stimulation-evoked [Ca(2+)](i) and exocytosis. This study further underlines the need to consider presynaptic, non-receptor-mediated effects in human risk assessment.

Identification of genes expressed as a result of lindane exposure in Oreochromis niloticus using differential display.

In order to assess the effect of lindane exposure on gene expression in tilapia (Oreochromis niloticus), twenty male fish were individually weighted and injected intraperitoneally with a single dose of lindane (19.09 mg/kg bw) using corn oil as a carrier vehicle, while a second group of twenty male fish (controls) was only injected with the carrier vehicle. Groups of four fish each were then sacrificed at 3, 6, 12, 18 and 24h after treatment application and total RNA was extracted from liver tissue. The differential display (DD) technique was then used to identify differentially expressed cDNA fragments between treatment and control fish. A total of fifty cDNA fragments were isolated and sequenced, from which only four showed homology with genes previously described in other fish species, namely the immunoglobulin heavy chain (IgH), coagulation factor V (FV), casein kinase 2 alpha (CK2a), and the receptor protein-tyrosine-like phosphatase (RPT-LP). The expression of such genes was confirmed using quantitative real time-polymerase chain reaction (QRT-PCR). Results showed that lindane exposure triggered the differential expression of these genes during the first 6, 18 and 24h subsequent to treatment application, suggesting that lindane exposure can trigger a rapid immune system response in tilapias.

Reflexões sobre alguns ensaios com o Gammexane no combate aos transmissores da doença de Chagas, de Emmanuel Dias e José Pellegrino, 1948: conquistas e desafios no contexto da diversidade triatomínica, cem anos após a descoberta da tripanossomíase americana / Reflections on some tests with the Gammexane transmitters in the fight against Chagas disease, Emmanuel Dias and Joseph Pellegrino, 1948: achievements and challenges in the context of triatomine diversity, one hundred years after the discovery of American trypanosomiasis

Revisões históricas aos avanços científicos para o controle da doença, o Simpósio Internacional Comemorativo do Centenário da Descoberta da Doença de Chagas (1909-2009).