Effects of Environmental Stress on the Architecture and Permeability of the Rat Mesenteric Microvasculature

Objective : This study was performed to determine the effects of environmental stress on the leakage to albumin and architecture of microvessels in the rat mesentery. Methods : One group of rats (Group A, n = 6) were examined immediately upon arrival at the animal care facility. Groups B (n = 24) and C (n = 32) were housed in rooms with high and low personnel activity, respectively, for up to 7 weeks. Group D (n =18) was housed in the high activity room for 2, 3, or 4 weeks followed by the low activity room. Results : Rats in the low activity room for 3–4 weeks showed robust microvascular networks within 25% to 50% of the mesenteric windows (each window consisting of the tissue extending between two adjacent feeding arterioles in the mesentery), whereas rats in Group B only showed fragile vessels at the edges of the mesenteric windows within fat deposits. Groups A and C demonstrated little mesenteric fat and few fragile vessels, in contrast to group B. Group D showed increased mesenteric networks and decreased mesenteric fat as recovery progressed. The microvascular networks of 6 rats, randomly selected from Group C, showed few venular leaks following perfusion with fluorescein isothiocyanatelabeled bovine serum albumin (FITC-BSA). Such leaks were abundant in the mesenteric microvasculature of 3 rats randomly selected from Group B. Conclusions : This study demonstrates that environmentally induced stress alters the architecture and leakage to albumin of the rat mesenteric microvasculature, and emphasizes the importance of closely monitoring the environment of experimental animals.     

Hydroquinone: A Developmental Toxicity Study in Rats

To determine the potential developmental toxicity of hydroquinone(HQ), pregnant rats (COBS-CD-BR) were given 0, 30, 100, or 300mg/kg HQ by gavage on the 6th through the 15th days of gestation.Maternal effects included a slight, but significant (p 0.05),reduction in body weight gain and feed consumption for the 300mg/kg HQ dams. Reproductive indices, i.e., pregnancy rate, numbersof corpora lutea, implantation sites, viable fetuses, and earlyand late resorptions, fetal sex ratio, pre-and postimplantationlosses, and gravid uterine weights, were not affected by treatmentwith HQ. A slightly reduced (p 0.05) mean fetal body weightseen at the 300 mg/kg dose level was associated with the slightlyreduced body weight gain seen for the dams at this dose level.Gross external, internal soft tissue, and skeletal examinationsof the fetuses revealed no HQ-related malformations. The incidencesof gross external variations (small hematomas) and internalsoft tissue variations (dilated renal pelvis, hydronephrosis,and hydroureter) in the HQ-treated litters were not statisticallydifferent from the control incidences. Skeletal variations (delayedossification of membranous skull bones, hyoid bone, thoraciccentra 1–3, sacral arches 3 and 4, and bilobed thoraciccentra 9–13) were seen with similar frequency in the controland HQ-treated groups. A statistically significant increasein the incidence of total common vertebral variations seen atthe 300 mg/kg HQ dose level was not considered toxicologicallysignificant. The incidences of total skeletal variations werenot statistically different between the control and the HQ-treatedgroups. It is concluded that HQ was not selectively toxic tothe developing rat conceptus and, thus, appears not to havethe properties of a developmental toxicant. The no-observable-effectlevel for both maternal and developmental toxicity was 100 mg/kg,whereas 300 mg/kg was the no-observable-adverse-effect level.     

Defining ‘competency’ in nursing (Part I): a policy review

• ? How the nursing profession in England defines the basic competency of the registered general nurse is crucial for the safety of the patient and the protection of the nurse. It is also essential for determining advanced practice, extended practice and specialist practice in nursing.
• ? An historical overview of documentation from the United Kingdom Central Council for Midwifery and Health Visiting, the English National Board for Nursing, Midwifery and Health Visiting and the Royal College of Nursing shows a profound change in educational policy during the 1980s regarding the interpretation of nursing competency.
• ? The effects of this policy change on the current methods developed to define, teach and test nursing competency are examined.
• ? Preliminary conclusions show shortcomings and uncertainty in the present preparation and evaluation of nursing competency.

     

Economic Implications of an Early Postoperative Enteral Feeding Protocol

OBJECTIVE: To study the cost-effectiveness of an early postoperative feeding protocol for patients undergoing bowel resections. DESIGN: A nonrandomized, prospective, clinical trial. Surgeons elected to participate in the treatment arm before the study's outset. SUBJECTS/SETTING: Treatment (n = 66) and control (n = 159) patients were admitted to a nonprofit general teaching hospital in the Texas Medical Center for similar diagnoses and subsequent bowel resections during an 18-month period. INTERVENTION: Treatment patients who met specific inclusion criteria had a jejunal feeding tube placed during surgery. Tube feedings were initiated within 12 hours after surgery. Control patients who met the same inclusion criteria received usual care. OUTCOMES: A successful outcome was defined as a patient developing no postoperative infection. The average cost of a nosocomial infection is presented. Variable direct and total costs (fixed plus variable) are compared between patient groups. STATISTICAL ANALYSIS: Mean cost was adjusted for rate of success in each patient group according to an analytic model. The mean cost difference between groups was analyzed by independent-samples t tests. Nonparametric Mann-Whitney rank sum tests were used to determine the cost significance of a nosocomial infection. RESULTS: The average variable direct cost savings per successful treatment patient was $1,531, which required an additional variable cost of $108.30 for the dietitian's time. The protocol resulted in a total cost savings of $4,450 per success in the treatment group. CONCLUSION: An early postoperative enteral feeding protocol as part of an outcomes management program for patients undergoing bowel resection is cost-effective.     

Patient Use of a Paediatric Hospital Casualty Department in the East End of London

This paper describes two surveys carried out at the accidentand emergency department of Queen Elizabeth Hospital, a specialistchildren's hospital situated in the east end of London. Bothstudies explored factors influencing attendance at the accidentand emergency department. One was based on an analysis of recordedinformation (hospital notes) for a random sample of attenders,spread over a 12-month period. The second was based on personalinterviews with a sample of children's parents. Both studiesfound problems with access to general practitioner care to bethe main factors influencing attendance.     

Renal Glutathione and Mercury Uptake by Kidney

Renal Glutathione and Mercury Uptake by Kidney. BERNDT, W. O.,BAGGETT, J. MCC., BLACKER, A., AND HOUSER, M. (1985). Fundam.Appl. Toxicol.. 5,832-839. The kidney is well documented asthe target organ for mercuric ion. Mechanisms by which thision accumulates in renal tissue, however, are less well understood.Sulfhydryl groups in renal tissue might well bind this metaland serve as a sink for its accumulation. Various studies haveindicated that both methyl mercury as well as mercuric ion areaccumulated less by renal tissue after depletion of nonproteinsulfhydryl groups. A similar reduction in hepatic accumulationof mercuric ion or methyl mercury does not occur after nonproteinsulfhydryl depletion. This observation may relate to the highertissue content of nonprotein sulfhydryls in liver than kidneyor to a fundamentally different mechanism of metal uptake. Mercuricion accumulation by renal tissue also can be reduced by ureteralocclusion, a reduction that is less than that for inulin incomparable experiments. These data are complex and do not clearlyestablish a role for filtration in the delivery of mercury tothe kidney. Inhibition of the renal enzyme glutamyl transpeptidase(-GT) results in a marked increase in the excretion of bothglutathione and mercury in the urine. Although there is a tendencyfor kidneys of the GT-inhibited animals to contain less mercurythan controls, the change in renal content was not significant.These observations suggest that -GT may have a role in the reabsorptionof mercury from the tubular lumen. Interestingly, both mercuricchloride-induced mortality and effects on renal slice accumulationof organic ions were enhanced in the presence of nonproteinsulfhydryl depletion caused both by immediate depletion of theglutathione pool and by inhibition of its synthesis.     

Stability of motor problems in young children with or at risk of autism spectrum disorders,ADHD, and or developmental coordination disorder

Aim The aim of this study was to investigate the stability of motor problems in a clinically referred sample of children with, or at risk of, autism spectrum disorders (ASDs), attention‐deficit–hyperactivity disorder (ADHD), and/or developmental coordination disorder (DCD). Method Participants were 49 children (39 males, 10 females; mean age 5y 6mo, SD 10mo) with various developmental problems, a Movement Assessment Battery for Children (M‐ABC) score on or below the 15th centile, and an IQ of 70 or more. Sixteen children were at risk of developing ADHD, 15 children had a diagnosis of, or were at risk of developing ASD, and 18 children had neither diagnosis. Children were reassessed 2 to 3 years later. Results At follow‐up (mean age 7y 11mo; SD 1y), the mean M‐ABC score was significantly increased, and in 22 children was no longer below the 15th centile. A general linear model to compare the difference in M‐ABC scores in the three groups of children demonstrated a significant difference between groups (p=0.013), with the age at the initial assessment as a significant covariate (p=0.052). The group of children with or at risk of ASD showed less improvement in motor performance. Interpretation Motor problems among preschool age children are not always stable, but appear to be so in most children with ASDs.