Gene disruption in Salmonella typhimurim by modified λ Red disruption system.

There are many techniques to knock out directed genes in bacteria, some of which have been described in Salmonella species. In this study, a combination of SOEing PCR method and the λ Red disruption system were used to disrupt phoP gene in wild type and standard strains of Salmonella typhimurium. Three standards PCR and one fusion PCR reactions were performed to construct a linear DNA including upstream and downstream of phoP gene and Kanamycin cassette. As a template plasmid, we used pKD4 which carries kanamycin gene flanked by FRT (FLP recognition target) sites. The resulting construct was electroporated into prepared competent cells of S. typhimurium. The transformants colonies related to the standard strain appeared on the LB-Km-agar plates after incubation, but there was no colony on LB-Km-agar plates corresponding to the wild type strain. The failure in transformation of the wild type strain may be because of inflexibility of the λ Red disruption system in this strain or its unique restriction-modification system. However, by this construct we are able to generate phoP mutant in many of the Salmonella species due to high homology of the phoP gene which exists in different species.

Using computer-guided implantology in flapless implant surgery of a maxilla: a clinical report.

The current notion in implantology is to utilize techniques that can provide function, aesthetics and comfort with a minimally invasive surgical approach. The flapless implant surgery has been suggested to fulfil these requirements. Traditionally, the flapless implant surgery was performed by using a tissue punch technique, which may be potentially harmful because of the inherent blindness of the technique. Today, computer software programs and 3D radiographic techniques, such as CT technology, have been developed to provide the practitioner with precise implant placement planning. Although this sophisticated approach has many advantages, transferring this information to the surgical phase has only recently been developed. The purpose of this paper was to introduce a more predictable flapless approach for treatment of a patient's maxilla through principles of computer-assisted implantology.

Histocompatibility leukocyte antigens in Rokitansky-Küster-Hauser syndrome.

Histocompatibility leukocyte antigens of 32 patients with Rokitansky-Küster-Hauser syndrome were compared with a control healthy population of 100. For analysis chi 2 with Yates' correction and Bonferroni criterion for multiple comparisons were used. Seven antigens were significant in the chi 2 test, but only three were confirmed in the Bonferroni criterion (Aw19, DRw52, and DQw1) (p < 0.001). The study showed certain associations between Rokitansky-Küster-Hauser syndrome and the major histocompatibility complex.

The Use of Veress Needle and 10-mm Trocar (VN) Versus Direct Trocar Insertion (DTI) in the Beginning of Laparoscopy

Seven hundred fifty-six women were randomly divided into two groups. Group 1 (378 cases) were operated on via laparoscopy with VN and group 2 (378 cases) with DTI technique. Complications were compared between the two groups. No major complications occurred. Minor complications were: a problem with insufflation of CO2 (19 VN, 2 DTI, P<0.001); more than one insertion of the instrument (18 VN, 13 DTI, NS); need to alter the technique (6 VN, 10 DTI, NS); and penetration of the fascia but not the peritoneum by trocar sleeve (2 VN, 19 DTI, P<0.001). The significant differences found presented no serious problems, and we concluded that both methods were satisfactory.

Change of milk yield with clinical diseases for a high producing dairy herd.

Changes in milk production associated with occurrence of clinical diseases (dystocia, stillbirth, twin births, milk fever, retained placenta, displaced abomasum, limping due to foot lesions, metritis, ketosis, and mastitis) were investigated. Data were collected daily on 388 lactation. Stepwise least squares regression was used to evaluate existence of associations between diseases and six yield measures that characterized milk production in the first 119 d postpartum. Logistic regression was used to investigate whether milk yield 1 to 5 d in milk might be of use to detect cows with early postpartum metritis (less than 21 d after calving). Lower milk production to 5 d postpartum was associated with an increased risk of early postpartum metritis in the logistic regression model. Yield to 5 and to 21 d postpartum was lower in cases of stillbirth, retained placenta, and early postpartum metritis. Yield from 22 to 49 d postpartum remained lower in cows diagnosed with early postpartum metritis. Milk yield losses occurred during diagnosis and treatment of displaced abomasum and mastitis. Ketosis was associated with yield losses prior to and at treatment. Ketosis to 21 d in milk was also associated with lower production after treatment. Limping diagnosed in the first 49 d postpartum coincided with higher yield to 5 d, to 21 d, and after 49 d postpartum.

Modeling mortality fluctuations in Los Angeles as functions of pollution and weather effects.

Linear and nonlinear models are used to investigate possible associations between mortality and pollution and weather effects in Los Angeles County. State-space modeling and time and frequency domain regressions are used to modify the data base and to isolate significant weather factors and pollutants associated with increased daily mortality. Nonparametric and parametric regression methods are used to develop nonlinear dose-response profiles relating mortality to temperature and to the statistically significant pollutants. A parametric nonlinear time series model involving linear and squared terms in temperature and the logarithm of pollution provides a reasonable predictive model.