Chemical mutagenesis of the parasitic nematode Strongyloides ratti to isolate ivermectin resistant mutants.

We describe a strategy for the mutagenesis of the free-living adult generation of Strongyloides ratti and selection of worms carrying new mutations in the subsequent F2 generation of infective larvae. We demonstrate that this strategy is successful via the selection of infective larvae that are resistant to the anthelmintic ivermectin at a concentration of 10 ng/ml. The majority of these larvae were unable to give rise to patent infections when used to infect parasite naive rats, implying that the majority of the ivermectin resistance mutations confer pleiotropic defects on parasitic, but not on free-living, development.

Lung fluid balance during acute renal failure in sheep.

To determine whether uremia changes lung vascular permeability, we measured the flow of lymph and proteins from the lungs of acutely uremic sheep. Acute renal failure was induced by either bilateral nephrectomy or by reinfusing urine. Both models of renal failure increased the plasma creatinine from 0.8 +/- 0.3 to 11 +/- 1 mg/dl in 3 days but caused no significant change in the flow of lymph from the lungs. To determine whether uremia increased the protein clearance response to elevated pulmonary microvascular pressures, we inflated a balloon in the left atrium for 2 h before and 3 days after inducing acute renal failure. In seven sheep, before removing the kidneys, the 20 cmH2O elevation of left atrial pressure increased the protein clearance 3.9 +/- 3.0 ml/h (from 9.5 +/- 4.9 to 13.4 +/- 5.4 ml/h). Three days after the bilateral nephrectomy the same increase in left atrial pressure increased the protein clearance 6.4 +/- 3.6 ml/h (from 6.1 +/- 2.1 to 12.5 +/- 5.2 ml/h), which was a significantly larger increase than that measured before the nephrectomy (P less than 0.05). Sham nephrectomy in seven sheep caused the protein clearance response to the elevated left atrial pressure to fall from 4.7 +/- 1.9 ml/h before the sham nephrectomy to 2.6 +/- 1.4 ml/h 3 days later (P less than 0.05). Uremia due to reinfusion of urine in five sheep did not affect the protein clearance response to elevations in left atrial pressure. Neither model of acute uremia increased the postmortem extravascular lung water volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Identifying the responsibilities & needs of working adults who are primary caregivers.

1. Caregivers of the elderly are mostly married women caring for mothers by completing household chores and personal care, managing finances and providing financial support, transportation, and companionship. 2. Caregivers attribute a variety of health care problems related to the burden of caregiving and miss an average of 8 days of work a year related to caregiving responsibilities. 3. The majority of caregivers express ten educational needs that would be helpful in their caregiving activities.

Endoscopic ultrasound for esophageal and gastroesophageal junction cancer: Impact of increased use of primary neoadjuvant therapy on preoperative locoregional staging accuracy.

Initial treatment of locally advanced esophageal and gastroesophageal junction (GEJ) malignancies for selected patients at some institutions has recently changed from surgical resection to neoadjuvant therapy. The aim of this study is to evaluate the impact of this change in treatment strategy on both the overall disease profile and locoregional endoscopic ultrasound (EUS) staging accuracy for a cohort of patients managed with primary surgical resection over a 10-year period at our institution. All subjects at our institution who underwent primary esophagectomy from 1993 to 2002 following preoperative EUS for known or suspected esophageal and/or GEJ cancers were identified. Patients with dysplasia alone, prior upper gastrointestinal tract surgery, preoperative neoadjuvant therapy, cancer of the gastric cardia or recurrent malignancy were excluded. EUS findings and staging results were compared to surgical pathology following resection. The impact of the gradually increased use of primary chemoradiation during the second half of the study was assessed. Of the 286 operations performed, 184 subjects were excluded. The remaining 102 underwent primary surgical resection a median of 18 days following EUS staging for adenocarcinoma (88%) or squamous cell carcinoma (12%) of the esophagus (69%) or GEJ (31%). Overall EUS locoregional T and N staging accuracy was 72% and 75% respectively; accuracy for T1, T2, T3 and T4 cancer was 42%, 50%, 88% and 50% respectively. Despite an increased frequency of pathologically confirmed T1 and T2 cancers (P = 0.005) and an insignificant trend toward increased N0 malignancy (P = 0.05) during the second half of the study period, no statistically significant changes in T (P = 0.07) or N (P = 0.82) staging accuracies for EUS or disease characteristics were noted between the first and second half of the study period. Despite both inaccurate radial EUS staging and increased relative use of primary surgery for early cancers, recent increased use of primary neoadjuvant therapy did not change overall disease characteristics and accuracy of locoregional EUS staging of esophageal and GEJ cancers managed with primary surgical resection.

Postoperative nosocomial pneumonia: nurse-sensitive interventions.

Nosocomial pneumonia (NP) is well documented as the second most common nosocomial infection. It is now more common in surgical patients than surgical-site or wound infection. Healthcare implications of NP include not only increased patient morbidity and mortality, but also increased use of healthcare resources. The advanced practice nurse plays an integral role in the prevention and minimization of NP across healthcare settings. This article focuses on postoperative NP after abdominal, cardiac, or thoracic surgery in the non-mechanically ventilated patient and discusses the diagnostic assessment, risk factors, and potential nurse-sensitive interventions to prevent or minimize this complication. Ideas for potential nursing research related to these risk factors are described.

Self-disclosure and coping styles in men with cardiovascular reactivity.

The purpose of this study was to investigate self-disclosure, emotion-focused, and problem-focused coping styles among men with borderline hypertension and two groups of normotensive men differentiated by parental hypertension. Because blood pressure reactivity may discriminate between hypertensive and normotensive men, subjects in these three groups were categorized as high or low cardiovascular reactors based on their blood pressure response to a mental arithmetic task. Self-disclosure and coping styles were investigated in relation to status effects within the doctor-patient relationship. Men with exaggerated blood pressure reactivity were less self-disclosive and used fewer emotion-focused coping strategies than men with no blood pressure reactivity. Normotensives with a history of parental hypertension were less self-disclosive than normotensives without a history of parental hypertension.

Use of microwave oven for determination of postmortem water volume of lungs.

To determine if a microwave oven could be used to obtain accurate values of postmortem lung and blood water contents, we compared measurements made with a microwave oven to those obtained by drying the tissue in a vacuum oven set at room temperature. Tissue samples were obtained from 9 dogs and 10 sheep used for a variety of experiments resulting in a wide biological range of water fractions (0.74-0.88). The ratio of the values obtained by these two methods was 1.00 +/- 0.06 for dog tissues and 1.00 +/- 0.02 for sheep tissues. The use of a microwave oven for drying lung tissue and blood provides a measurement of lung water content that is not significantly different from values obtained by vacuum drying, but the microwave method requires only 1 h vs. several days or weeks.

Blood pressure norms for healthy young adults: relation to sex, age, and reported parental hypertension.

Blood pressure norms are presented for 1,522 white, healthy, nonsmoking, normotensive 18 to 22-year-old men and women as a function of age and parental hypertension. Age effects were observed for diastolic blood pressure among males only. Parental hypertension was related to higher systolic and diastolic blood pressure among young women, and women with two hypertensive parents had higher systolic blood pressure than women with one hypertensive parent. The use of oral contraceptives is likely to have affected these results. Directions for future research are given.

Heterogeneity of T-cell receptor alpha-chain complementarity-determining region 3 in myelin basic protein-specific T cells increases with severity of multiple sclerosis.

The pathogenesis of multiple sclerosis (MS) is thought to involve a T-cell-mediated autoimmune process. Experimental allergic encephalomyelitis (EAE), an animal model resembling MS, can be induced by immunization with myelin antigens such as myelin basic protein. The T-cell antigen receptor (TCR) usage in EAE is highly restricted in some strains of animals and experimental treatments targeting the TCR have been successful in EAE. Examination of the TCR beta-chain variable-region (V beta) usage of MBP-specific T-cell lines in MS patients has produced conflicting results. Our previous studies of TCR alpha-chain variable-region usage in monozygotic twins demonstrated a general skewing of the TCR repertoire in individuals with MS. This skewing became apparent only after stimulation with antigens; in peripheral blood lymphocyte preparations from individuals with MS V alpha 8-bearing T cells were preferentially selected by stimulation with myelin basic protein. In the present study we examined complementarity-determining region 3 of those V alpha 8-positive TCRs. Marked sequence heterogeneity was found in all individuals with severe MS. In contrast, restricted areas of complementarity-determining region 3 were found in healthy control individuals and in individuals with a mild form of MS. Sequences from tetanus toxoid-specific V alpha 8-positive T cells generated from the same individuals were relatively homogeneous within individuals regardless of disease activity and were distinct from the sequences of complementarity-determining region 3 in myelin basic protein-stimulated lines. These findings suggest that disease severity may be associated with increased heterogeneity of myelin antigen-specific T cells and could reflect an impaired ability of the immune system to down-regulate these anti-self responses.

Ice-pack test in myasthenia gravis: electrophysiological basis.

We report the first study in which the repetitive nerve stimulation (RNS) test was performed in conjunction with the ice-pack test in three patients with myasthenia gravis. All three patients showed an unequivocal improvement in ptosis on the side where an ice pack was placed. RNS test in the facial nerve revealed a definite improvement in the decremental response. From this we conclude that the ice-pack test produces a clinical and electrophysiological improvement in myasthenia gravis.

Platelets and uric acid in the prediction of preeclampsia.

Fifty-four pregnancies that were subsequently complicated by preeclampsia had platelet parameters and uric acid levels measured during pregnancy. The expected fall in platelet count and rise in platelet volume parameters and uric acid levels beyond those that occur in normal pregnancy were seen only in the week before delivery.