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.

The techniques used for diagnosis of head louse (Pediculosis capitis) infestation are a source of controversy. Most epidemiologic and diagnostic studies have been done using direct visual examination. The main objective of this study is to compare the efficacy of direct visual examination versus the louse comb method. The hair of each child was examined twice; one team used a screening stick and another team used a louse comb. Seventy-nine boys and 201 girls, 7-10 years old were examined. Examination with a louse comb found that 25.4% of the children were infested with both lice and nits, while another 31.3% had nits only. Boys were significantly less infested with lice and nits than girls (lice: 15.2 and 29.6%; nits: 21.5 and 35.4%, respectively). The infestation rate with lice and nits was significantly higher in children with long (68.9%) and medium-length (63.9%) hair than in children with short hair (44.0%) (p < 0.01). Direct visual examination found that 5.7% of the children were infested with both lice and nits, and another 49.0% with nits only. The average time until detection of the first louse was 57.0 seconds with the comb as compared to 116.4 seconds by direct visual examination. Diagnosis of louse infestation using a louse comb is four times more efficient than direct visual examination and twice as fast. The direct visual examination technique underestimates active infestation and detects past, nonactive infestations.

In Israel, the head louse, Pediculus capitis, developed resistance to DDT through the extensive use of this insecticide until the 1980s. In 1991, permethrin was introduced for control of DDT resistant P. capitis in Israel, leading to control failure of this pyrethroid insecticide by 1994. Pyrethroid resistance of P. capitis in Israel extends to phenothrin, which has not been used for louse control. We identified a glutathione S-transferase(GST)-based mechanism of DDT resistance in the Israeli head lice. This GST mechanism occurred before 1989, while permethrin resistance in P. capitis developed after 1994, suggesting that the main GST resistance mechanism selected by DDT use does not confer any pyrethroid cross-resistance. Esterase activity levels were equivalent in pyrethroid resistant and susceptible P. capitis field-collected in Israel, and in a susceptible strain of P. humanus, the body louse, indicating no involvement of any esterase-based mechanism in resistance. A weak monooxygenase-based permethrin metabolism resistance mechanism was the only factor identified which could account for any of the observed pyrethroid resistance in P. capitis. However, the lack of synergism of phenothrin resistance by piperonyl butoxide suggests that a non-oxidative mechanism is also present in the resistant lice. Therefore it seems probable that pyrethroid resistance in Israeli P. capitis is due to a combination of nerve insensitivity (knockdown resistance or 'kdr') and monooxygenase resistance mechanisms.

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 children 4-11 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 2-5 cm 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.

LCR is a safe and effective approach for the treatment of patients with diverticular disease. It results in less estimated blood loss, shorter time to first bowel movement, less postoperative complications, and shorter length of hospital stay.

Laparoscopic colorectal resections has a relatively high conversion rate; however, the converted cases have outcomes similar to open colorectal resections. In fact, the converted group required fewer blood transfusions than the open group. Experience and good judgment are fundamental for timely conversion of a laparoscopic procedure to open to decrease complication rates. Despite a high conversion rate, surgeons should consider laparoscopic colorectal resections, because even when necessary, conversion does not result in poorer outcomes than laparoscopic colorectal resections or open colorectal resections.

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Five essential oils and nine of their components were compared to diethyl toluamide (DEET) for their repellent activity against the human body louse, Pediculus humanus humanus. The absolute or intrinsic repellency of the compounds was tested by applying the repellent to corduroy patches and comparing them with untreated patches. It was found that the most effective repellents were DEET and citronella, whose activity lasted at least 29 days. The activity of rosemary lasted at least 18 days and that of eucalyptus more than 8 days. The repellent activity of the oil components such as citronellal and geraniol lasted more than 15 and 8 days, respectively. DEET remained effective at a dilution of 1:32, geraniol at 1:8, citronella at 1:4 and rosemary and citronellal at 1:1. The comparative or standard repellency of the candidate repellents was examined with the aid of a new screening technique using hairs treated with ammonium bicarbonate which is attractive to lice. Using this technique it could be shown that the repellent activity of citronella and geraniol lasted 2 days and that of rosemary and citronellal for only one day. DEET was active for less than one day. Serial dilutions of these substances also revealed that citronella was the most potent repellent for lice, followed by citronellal, rosemary, geraniol and DEET. The differences however, were not significant.