Restriction map of a 35-kb HLA fragment constructed by nested deletion 'drop-out' mapping

An efficient method for generating detailed restriction maps of large cloned DNA segments is demonstrated. The mapping strategy entails comparing restriction fragments from a parent clone and from nested deletion derivatives of that clone. In a set of deletion plasmids of decreasing size, an individual fragment will be lost, or 'drop-out', according to its position in the cloned fragment. In this demonstration, nested deletions were generated in both directions in a 35-kb DNA segment from the human leukocyte antigen (HLA) region by intramolecular transposition of an engineered gamma delta (Tn1000) element present in a special 'deletion factory' cloning vector [Wang et al., Proc. Natl. Acad. Sci. USA 90 (1993) 7874-7878]. Fifteen plasmids with deletions extending in one direction and eleven plasmids with deletions extending in the opposite direction were digested singly by each of four restriction enzymes. A total of 36 cleavage sites were mapped in the 35-kb HLA fragment. This drop-out approach using nested deletions provides a simple and efficient means of mapping restriction sites, genes and other features of interest in cosmid-sized cloned DNA segments or DNAs.     

A prospective study of primary and secondary risk factor management in stroke patients

Stroke is a common event which often results in death or major loss of independence with immense human and financial costs, so identification of patients at risk, and prevention of stroke at the individual and population levels, is a high clinical and health priority. From August 1993 to July 1994, 468 stroke patients admitted to our hospital were assessed for the presence of stroke risk factors. All patients were followed up in hospital, and on discharge or death all hospital records were reviewed. We show that many risk factors remain uncorrected in stroke patients and that preventive measures are less than ideal at the community and hospital levels alike.     

Purinoceptor activation of chloride transport in cystic fibrosis and CFTR-transfected pancreatic cell lines

The regulation of chloride efflux from cystic fibrosis pancreatic adenocarcinoma cells (CFPAC-1) and wild-type CFTR-transfected CFPAC-1 cells (TPAC) was compared. Forskolin (10 microM) stimulated chloride efflux from the corrected TPAC cells but not from CFPAC-1 cells. Chloride efflux from both cell types was activated by thapsigargin (0.5 microM). The nucleotides ATP and UTP and the non-hydrolyzable ATP analogue, adenosine 5'-O-(3-thio) triphosphate (ATPgammaS), stimulated chloride efflux from both cell types. None of the other P2 purinoceptor agonists investigated elicited a response. The order of potency was ATP > or = UTP > or = ATPgammaS. Adenosine (10-100 microM) activated choride efflux from the TPAC but not the CFPAC cell line with no increase in intracellular cyclic AMP. Small but statistically significant inhibitions of the adenosine-(50 microM)-stimulated increase in chloride efflux were elicited by the A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (CPX, 100 nM) and the A2 receptor antagonist 3,7-dimethyl-1-propylargylxanthine (DMPX, 10 microM). The A2A receptor antagonist 8-(3-chlorostyryl)caffeine (CSC, 100 nM) had no significant effect. These results provide evidence for the regulation of chloride efflux by P2Y2 purinoceptors in genetically-corrected and CF pancreatic cell lines. Studies with adenosine receptor antagonists indicate some possible involvement of A1 and A2 (but not A2A) receptors in the adenosine stimulation of chloride efflux, but the relatively small effects of the inhibitors coupled with lack of increase in cyclic AMP and a response only in the CFTR-transfected cells also suggests a possible direct effect of adenosine on CFTR.     

Effects of endothelin-1 on hippocampal synaptic plasticity

We examined the effects of puff application of endothelin (ET)-1 on the induction of long-term potentiation (LTP) and heterosynaptic long-term depression (LTD) in hippocampal CA1 slices. ET-1 applied 2 min prior to tetanus blocked the induction of LTP, but facilitated the induction of heterosynaptic LTD. These ET-1 effects on synaptic plasticity were dose-dependent, and not due to a generalized depression of baseline responses. ET-1 did not alter NMDA receptor-mediated responses. These data provide the first evidence that endothelin modulates activity-dependent synaptic plasticity, and the potency of these effects suggests that endogenous ET-1 may play an important role in regulating memory storage processes.     

Effects of extrusion and expelling on the nutritional quality of conventional and Kunitz trypsin inhibitor-free soybeans

Two chick growth experiments and a precision-fed cockerel digestibility assay were conducted to evaluate the effect of extrusion and expelling on the nutritive value of conventional (CSB) and Kunitz trypsin inhibitor-free (KFSB) soybeans. In the first experiment, performance of chicks fed CSB or KFSB autoclaved at 121 C was similar to that of chicks fed CSB or KFSB extruded at 138 C. The effect of extrusion temperature on protein quality of the soybeans was evaluated in the second experiment. Eleven corn-soybean diets were formulated to contain one of the following: CSB extruded at 104, 121, 138, or 154 C; KFSB extruded at 104, 121, or 138 C; CSB extruded at 121, 138, or 154 C followed by processing through an expeller; and commercial dehulled solvent-extracted soybean meal (SBM). All diets contained 20% crude protein and the same amount of soybean oil and were fed to chicks from 7 to 21 days of age. The CSB extruded at 104 or 121 C and KFSB extruded at 104 C yielded depressed growth and feed efficiency compared with SBM. Performance of chicks on the other treatments was similar to that of chicks fed SBM. Pancreas weight (as a percentage of BW) decreased as extrusion temperature increased, with the response being greater for CSB. Growth performance was greater and pancreas weights were lower for chicks fed KFSB extruded at 104 or 121 C compared with those of chicks fed CSB extruded at the same temperatures. Expelling improved weight gain and feed efficiency when CSB was extruded at 121 C. A 48-h digestibility assay with cecectomized cockerels indicated that digestibility of amino acids in CSB and KFSB increased as extrusion temperature increased and that digestibilities of amino acids in CSB extruded at 104 or 121 C were lower than those in KFSB extruded at the same temperatures. Results of this study indicated that extrusion of CSB at 138 to 154 C or extrusion of KFSB at 121 to 138 C yields protein quality similar to that of SBM.     

Ethanol injection: technique and method of performance

The authors describe the technique used in the treatment of autonomously functioning thyroid nodules by percutaneous ethanol injection (PEI). They illustrate the free-hand technique followed in their hospital from January 1990 to October 1992 in a group of 25 patients. Results, advantages and disadvantages of this technique are reported and compared with the ultrasound-guided technique. In the latter, widely used, the needle is positioned in the target nodule by means of an ultrasound probe with a specially designed guiding device which forces the needle in the correct direction. This makes the manoeuver rapid and safe as the needle tip can be easily visualized. In this case, the most important drawback lies in the impossibility of changing the ultrasound scanning plane during the ethanol injection as the probe and the needle are fast together. So the correct spreading modality of ethanol inside the tissue is not completely checked. Another disadvantage is the cost of disposable guiding device necessary in order to avoid contamination. On the other side, in the free-hand technique the needle is aimed at the nodule and inserted during an ultrasound examination without restrain on the probe movements. In this way, it is possible to focus the attention on the critical structures to prevent their damage stopping ethanol injection as soon as a seepage outside the thyroid occurs. Furthermore, this technique is particularly inexpensive as a standard probe is used and the risk of contamination can be avoided by just wrapping the probe with a sterline plastic film.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coping and emotion in women undergoing cardiac surgery: a preliminary study

There is limited knowledge about how women manage the experience of cardiac surgery. This pilot study examined how women coped with surgery and their emotions in the perioperative period. There was no change in coping or emotion from the day before surgery to the fifth postoperative day, and coping was unrelated to emotion. Preoperative and postoperative confusion and distress were positively correlated. While preliminary, these results raise implications for medical-surgical nursing practice and research.