Developing and testing of an Egyptian version of Children's Health Locus of Control scale

The purpose of this study is to develop and test the reliability and validity of an Egyptian version of the Children's Health Locus of Control scale. A cross sectional study design was applied using a stratified random sample of 930 students from the final two grades of primary and all grades of the preparatory schools. A further convenience sample of 120 students was selected to examine test-retest reliability of the scale. A preliminary instrument was developed and consisted of 40 statements having one of two response forms; a Yes/No format and a 4-point Likert scale format From data analysis the later format showed higher validity and reliability than the former one. Construct validity of the scale is evidenced by the factor analysis which revealed five factors (Internal, Chance, Powerful Others, Fate and Self blame) consistent with the previous theoretical model of HLC. As indicated by eta coefficient the scale and the subscales showed strong discriminating power between subjects. The known group comparison indicated a good criterion validity of the scale and the subscales. The scale showed a considerable reliability as alpha coefficient was 0.73 with test-retest reliability of 0.65. Comparison of different groups of students indicated that the scale could be used with confidence for all age groups, though it was more reliable for the preparatory phase, for private and governmental schools for males and females and for different social strata. Further testing of the developed scale is indicated among Egyptian children in different cultures.     

Percutaneous cuffed catheter insertion by nephrologists

The use of Dacron cuff double-lumen permanent catheters for hemodialysis has become more common in the dialysis unit as patients await for creation or maturation of a permanent hemoaccess for various reasons. Placement of these catheters is often done by surgeons. Nephrologists skilled in the placement of temporary central vein accesses can extend their skill to placement of cuff catheters with the current available peel-away insertion technique. Data are presented on the percutaneous placement of 77 Dacron cuff permanent catheters by 4 nephrologists in two medical centers in a nonoperating room setting with minimal complications.     

Peptide vaccination using nonionic block copolymers induces protective anti-viral CTL responses.

High molecular weight nonionic block copolymers have been developed as vaccine adjuvants. We employed these adjuvants in water-in-oil emulsion and multiple emulsion formulations with a synthetic peptide-based antigen vaccine to test their ability to prime anti-viral CD8(+) T cell responses. Vaccines were made using the H-2(d)-restricted immunodominant peptide from lymphocytic choriomeningitis virus (LCMV), NP118-126, and administered to BALB/c ByJ (H-2(d)) mice. Peptide-containing emulsions were able to induce NP118-126 specific CTL and IFN-gamma secreting CD8(+) T cells in the vaccinated mice and these responses were maintained for at least 90 days post immunization. At all times, the responses induced by the copolymer formulations were equal to, or better than, formulations based on incomplete Freund's adjuvant (IFA). In addition, the responses induced by prophylactic vaccination using the multiple emulsion formulation resulted in accelerated viral clearance following infection with a strain of LCMV (clone 13) that causes a persistent infection in na?ve adult mice. These results indicate that peptide vaccination using a formulation based on high molecular weight nonionic block copolymer in a simple water-in-oil or a multiple emulsion format can induce virus-specific CD8(+) T cell responses and confer protection sufficient enough to prevent the establishment of a persistent infection.     

Epidemiology of child deaths due to drowning in Matlab, Bangladesh.

BACKGROUND: Although the recent decline in child mortality in Bangladesh is remarkable, death from causes other than infectious diseases and malnutrition remains an important component of child mortality. Death from drowning of children can be expected to be a problem in Bangladesh given the geographical features of the country. OBJECTIVE: The objectives of this study are to determine the trend, pattern, and correlates of drowning deaths. METHODS: Data are presented on deaths of children (1-4 years) due to drowning derived from a longitudinal, population-based surveillance system in operation in a rural area of Bangladesh in 1983-1995. Moreover, a case-control study was carried out to identify the risk factors associated with drowning. RESULTS: Deaths due to drowning ranged from about 10% to 25% of child deaths during 1983-1995. The absolute risk of dying from drowning remained almost the same over the study period but the proportion of drownings to all causes of death has increased. Drowning is especially prevalent in the second year of life. Age of the mother and parity have a significant impact on drowning. The risk of dying from drowning increases with the age of mother and much more sharply with the number of living children in the family. Two socioeconomic variables did not have an influence on the risk of drowning. CONCLUSIONS: A substantial proportion of child deaths could be averted if parents and other close relatives paid more attention to the safety of children. The Child Health Programme of the Ministry of Health and Family Welfare of Bangladesh should develop health education programmes for villagers alerting them to the dangers of drowning and measures to prevent it.     

Long-lasting increase in the set point for cocaine self-administration after escalation in rats

Rationale: When access time to a continuous schedule of drug self-administration is restricted, animals tend to limit intake to a certain level over time and across doses. This observation suggests an endogenous constraint or set point that determines the individual’s preferred level of pharmacological effects. Objectives: To assess whether the transition to increased levels of drug intake is associated with a change in set point. Methods: Two groups of rats were trained on a 1-h continuous schedule of cocaine self-administration (250 μg/injection), after which access to cocaine was increased to 6 h in one group (Long Access or LgA rats) or kept to 1 h in the other group (Short Access or ShA rats). After 22 sessions on this regimen, different doses of cocaine were tested (31.25, 62.5, 125, and 250 μg/injection). For each dose, the post-response time-out period was reduced to 4 s to reduce any temporal limitations on self-injections and subjects were tested several times. Results: In LgA rats, the first hour intake escalated over time and eventually reached a level 200% greater than that of ShA rats. Though all rats maintained relatively constant intake across doses, LgA rats took nearly two times as much cocaine than ShA rats. When access to cocaine for LgA rats was reduced to 1 h, intake returned very slowly toward pre-escalation levels but was still elevated even after 2 months of reduced availability. Conclusions: These data suggest that the transition to escalated levels of intake is associated with a long-lasting change in cocaine set point. Received: 12 February 1999 / Final version: 21 May 1999     

A Novel technique of ureteroneocystostomy (extravesical seromuscular tunnel): An experimental study in dogs. II. Optimization of surgical technique

Objectives

To optimize the surgical technique of the new extravesical seromuscular tunnel ureteroneocystostomy and to study the optimal relation between the length and width of the tunnel and the diameter of the normal and dilated ureters.

Methods

The optimized technique was applied to the left ureters of 20 dogs; 10 with normal ureters and 10 after induction of ureteral dilation. The new technique was performed to maintain a ratio of 3:1 between the width of the tunnel and the diameter of the ureter and a ratio of 1:1 between the length of the tunnel and the ureteral diameter. The results were compared with those for 5 dogs in which unilateral direct ureterovesical reimplantation was performed without an antireflux procedure. All the dogs were evaluated by intravenous urography, radioisotope renography, and ascending cystography before and at 1, 3, and 6 months after ureteroneocystostomy.

Results

All the dogs of the control group showed low-pressure vesicoureteral reflux and 3 demonstrated mild hydronephrosis and significant deterioration of the corresponding kidney. At 6-month follow-up, none of the 20 dogs subjected to the new technique showed deterioration of the function or configuration of the corresponding kidney. Moreover, the new technique was sufficient to prevent reflux in all but two dilated ureters that showed high-pressure vesicoureteral reflux.

Conclusions

For the extravesical seromuscular tunnel to be effective in reflux prevention without obstruction, the width of the tunnel must be triple the diameter of the ureter, and the length of the tunnel covering the intact (nonspatulated) part of the ureter should be equal to its diameter.     

Leading causes of infant deaths in the District of Columbia

Causes of infant deaths were analyzed from the linked vital records of 1988 for the District of Columbia. According to a new cause-of-death classification, 57% of the deaths were attributed to "prematurity and related conditions," as compared with only 31% due to "disorders relating to short gestation and unspecified low birthweight" and respiratory distress syndrome (RDS) in the three-digit ICD-9 classification. Two thirds of infant deaths were "preventable." However, 92% of these occurred to infants weighing less than 1500 g. Not only was a greater proportion of black deaths (71%) preventable as compared to nonblacks (40%), but also 15% of the preventable deaths among blacks were due to causes unrelated to prematurity. The Infant Mortality Rate (IMR) in the District of Columbia would be reduced from 23.2 to 7.7 if all preventable deaths were prevented, to 20.9 if only the preventable deaths not related to prematurity were prevented, and to 15.2 if the percentage of "preventable" deaths among blacks was brought down to the level of nonblacks. Mortality from RDS was substantially higher in the District of Columbia compared with blacks nationally and appeared to offer the best opportunity for reduction. However, detailed examination of circumstances surrounding each infant death would be necessary to inform the strategies for the reduction in IMR.     

Tissue distribution and macromolecular interactions of 14[C-ring] melphalan in the rat

Summary The kinetics of uptake and elimination, covalent binding, and macromolecular interactions of ¹⁴[C-ring] melphalan was studied after a single oral dose (20 mg/kg, 0.1 mCi/kg) in normal rats. Peak radioactivity level in tissues was observed at 2–4 h after administration. Uptake of label in most tissues was rapid, with a t_1/2 of less than 1 h. Elimination was biphasic. Tissues of the gastrointestinal tract showed the most rapid rates of elimination, with t_1/2 of 13, 24, 18, and 19 h for stomach, duodenum, and small and large intestines, respectively. Bone marrow also showed a fast rate of elimination of radioactivity, with a t_1/2 of 30 h. Tissues with the slowest rates of elimination were skin, eye, spleen, pancreas, and lung, with t_1/2 of 333, 241, 149, 122, and 109 h, respectively. Covalent binding studies showed that melphalan, or its metabolites, bound irreversibly to all tissue macromolecular fractions. The percentage of covalently bound radioactivity increased with time in all tissues except kidney and eye, reaching up to 70%–80% of the total radioactivity remaining at 72 h. Elimination of covalently bound radioactivity was slower in the DNA fractions of the tissues of the gastrointestinal tract and heart compared with the elimination rate from lipid, protein, or RNA fractions. Slow elimination rates of ¹⁴[C-ring] melphalan equivalents from the protein fraction were observed in the skin, eye, and brain. Accumulation, rather than elimination, of radioactivity in this fraction was most prominent in the pancreas. In the bone marrow accumulation of radioactivity was observed in the lipid fraction.Abbreviations used in this paper are L-Pam Melphalan, l-phenylalanine mustard 4-bis (2-chloroethyl) amino-1-phenylalanine - l-DOH 4-bis (2-hydroxyethyl) amino-1-phenylalanine - l-MOH 4-2 hydroxyethyl 2 chloroethyl amino-1-phenylalanine - HPLC high-pressure liquid chromatography - TCA trichloroacetic acid - AUC area under the curve - GIT gastrointestinal tract