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Biomedical subjects

W R Thompson

Publications and source records attributed to W R Thompson.

At least 19 recordsLinked to original sources
PubMed1997

Regulation of the rat cardiac troponin I gene by the transcription factor GATA-4.

Troponin I is a thin-filament contractile protein expressed in striated muscle. There are three known troponin I genes which are expressed in a muscle-fibre-type-specific manner in mature animals. Although the slow skeletal troponin I isoform is expressed in fetal and neonatal heart, the cardiac isoform is restricted in its expression to the myocardium at all developmental stages. To study the regulation of this cardiac-specific and developmentally regulated gene in vitro, the rat cardiac troponin I gene was cloned. Transient transfection assays were performed with troponin I-luciferase fusion plasmids to characterize the regulatory regions of the gene. Proximal regions of the upstream sequence were sufficient to support high levels of expression of the reporter gene in cardiocytes and relatively low levels in other cell types. The highest luciferase activity in the cardiocytes was noted with a plasmid that included the region spanning -896 to +45 of the troponin I genomic sequence. Co-transfection of GATA-4, a recently identified cardiac transcription factor, with troponin I-luciferase constructs permitted high levels of luciferase expression in non-cardiac cells. Electrophoretic mobility-shift assays demonstrated specific binding of GATA-4 to oligonucleotides representative of multiple sites of the troponin I sequence. Mutation of a proximal GATA-4 DNA-binding site decreased transcriptional activation in transfected cardiocytes. These results indicate that the proximal cardiac troponin I sequence is sufficient to support high levels of cardiac-specific gene expression and that the GATA-4 transcription factor regulates troponin I-luciferase expression in vitro.

3T3 Cells↗
PubMed1997

Comparison of laparoscopic and open splenectomy in children with hematologic disorders.

OBJECTIVE: To compare laparoscopic and traditional open splenectomy in children with nonmalignant hematologic disorders. STUDY DESIGN: Retrospective review of 36 consecutive nonrandomized splenectomies (16 laparoscopic and 20 open) performed for hematologic disorders at a single pediatric institution during the past 3 years. The two-sided Mann-Whitney U test for non-parametric variables was used for statistical analysis. RESULTS: An open procedure was performed on 20 patients (mean age, 9.7 years), five of whom had a concomitant cholecystectomy. A laparoscopic splenectomy was performed on 16 children (mean age, 10.3 years), seven of whom had a concomitant cholecystectomy. The mean anesthesia and operative times were longer in the laparoscopic than in the open group (p < 0.001). However, the mean number of hours of postoperative analgesia was less in the laparoscopic group (p < 0.005). Patients who had laparoscopic splenectomy were also discharged home earlier (p < 0.01) and resumed a regular diet sooner. Mean operating room charges were higher in the laparoscopic group (p < 0.001), but total hospitalization costs were not significantly different. Postoperative complication rates were similar. The hematologic response was comparable. CONCLUSIONS: laparoscopic splenectomy is feasible and safe in children with hematologic disorders. Although it currently requires more operative time than the open approach, it is superior with regard to duration of postoperative analgesia, duration of hospital stay, and recovery of bowel function.

Adolescent↗
PubMed1996

Percutaneous dilational tracheostomy--a clinical study evaluating two systems.

Percutaneous dilational tracheostomy (PDT), first described in the 1950s, has become a common bedside technique in the Intensive Care Unit (ICU). This study compares the early complications associated with the use of the Ciaglia PDT (Cook Critical Care, Bloomington, USA) technique, with the newly available Portex PDT technique (Portex Ltd., UK). The Ciaglia technique was adopted in this ICU in July 1994 and twenty-nine patients had a tracheostomy using this set until January 1995. Complications during the procedure were collected prospectively. When the Portex PDT set became available in January 1995, it was decided to assess the complication rate of this technique and compare them to the previously-collected data using the Ciaglia PDT set. Twenty-five patients have had a tracheostomy using the Portex PDT set. There has been no mortality associated with either PDT set. Bleeding requiring intervention occurred in two patients in the Ciaglia group and three patients in the Portex Group. All these patients had a bleeding diathesis. Loss of airway control occurred on one occasion in the Ciaglia group due to premature removal of the endotracheal tube. The first routine tracheostomy tube change at day 7 was complicated in four cases in the Ciaglia group. One infected stoma was noted in the Ciaglia group at day 7. Both techniques result in rapid, safe placement of a tracheostomy tube in critically ill patients in the ICU, obviating the need for surgical referral and transport to the operating room.

Adolescent↗
PubMed1996

Inhaled aerosolized prostacyclin as a selective pulmonary vasodilator for the treatment of severe hypoxaemia.

Two case reports are presented where inhaled aerosolized prostacyclin (IAP) was used to good effect as a selective pulmonary vasodilator. It was used in the treatment of a patient with severe hypoxaemia secondary to amniotic fluid embolism and for hypoxaemia secondary to the acute respiratory distress syndrome (ARDS) in a patient with acute on chronic liver failure and intra-abdominal sepsis. An apparent dose-response curve is demonstrated in the second case. A dose of IAP of 30-40 ng/kg/min produced an effect on oxygenation in the patient with liver failure equal to that seen at the maximal dose of (50 ng/kg/min). Reduction in dose below 30 ng/kg/min resulted in a deterioration in oxygenation towards baseline/pre-treatment levels. Inhaled aerosolized prostacyclin is a potent pulmonary vasodilator with little or no systemic hypotensive effect. It is simple to administer and would appear to be a viable alternative to inhaled nitric oxide.

Administration, Inhalation↗
PubMed1996

Central venous catheters revisited--infection rates and an assessment of the new Fibrin Analysing System brush.

Sixty-one consecutive patients in the Intensive Care Unit requiring central venous lines (CVC) for five or more days were randomized to receive either a standard triple lumen CVC (STD/CVC) or a silver sulphadiazine and chlorhexidine impregnated CVC (SSD/CVC). Data from the 54 patients who completed the trial show a reduced infection rate (positive tip culture) in the SSD/CVC group (4 out of 28) compared to the STD/CVC group (10 out of 26) (P < 0.05). In addition, the new Fibrin Analysing System (FAS) brush was evaluated and used to determine the presence of infection in all the CVCs (STD/CVC and SSD/CVC combined, n = 54) at day 3 (i.e. early warning of CVC colonization/infection) and at the time of removal of the CVC. The FAS brush was able to detect an infected CVC on only one occasion on day 3 out of the 14 CVC tips which were later found to be colonized/infected at the time of removal. The sensitivity of the FAS brush in detecting colonized/infected CVCs at the time of CVC removal compared with CVC tip culture was 21% with a specificity of 100%. These findings would currently not support the routine use of the FAS brush in determining CVC infection/colonization.

Acinetobacter↗
PubMed1996

Laparoscopic Nissen fundoplication in the infant.

Twenty-five children weighing less than 8 kg underwent laparoscopic Nissen fundoplication for treatment of refractory gastroesophageal reflux (GER) between January 1993 and April 1995. Mean patient age was 6 months and weight was 5.1 kg. Mean operative time was 114 min, including gastrostomy in 20 patients. Nineteen patients are alive without evidence of GER with a mean follow-up of 359 days. Perioperative complications were unusual and mild. There were 6 late deaths due to progression of underlying disease and not attributable to the procedure. Laparoscopic Nissen fundoplication provides effective antireflux protection to very small children with acceptable morbidity and mortality through short-term follow-up.

Body Weight↗
PubMed1996

Laparoscopic splenectomy in childhood hematologic disorders.

Laparoscopic splenectomy is a new technique that is being utilized in patients with a variety of mostly hematologic disorders. Its application in children has not been extensively documented. Between January 1994 and February 1995, 11 children less than 15 years of age underwent elective laparoscopic splenectomy. Data collected from this treatment group were compared to that from the ten most recent open splenectomy patients with comparable hematologic disorders. All procedures in both groups were successful in relief of symptoms, increase in platelet count, and/or increase in hematocrit. Operative times averaged 147 mm in the laparoscopic group, compared to 112 mm in the open group. Estimated blood loss was 32 ml in the laparoscopic group and 86 ml in the open group. Days to laparoscopic patient discharge were 3.6, compared to 5.3 days in the open group. There were no wound complications or need for perioperative platelet transfusions in the laparoscopic patients. Patient response has been uniformly positive in the laparoscopic group. Reusable access trocars are utilized for two of the four working ports. Stapling devices and special tissue morselizers are not required. There are no additional operating room or surgeons fees incurred in the laparoscopic procedures. This series demonstrates that laparoscopic splenectomy is a safe, cost-efficient alternative to open splenectomy in children with a variety of hematologic disorders.

Adolescent↗
PubMed1995

Laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis: report of 11 cases.

Pyloromyotomy remains the standard of care for the treatment of infantile hypertrophic pyloric stenosis. Open pyloromyotomy is effective and is the gold-standard technique. The authors report on the techniques of laparoscopic pyloromyotomy. The clinical courses of the first 11 infants treated with laparoscopic pyloromyotomy we with the courses of 14 infants treated recently with open pyloromyotomy. The average surgical time for the laparoscopic group was 25.4 minutes. The average time (postoperatively) until full feedings was 19.0 hours. In the open pyloromyotomy group the average surgical time was 26.1 minutes, and the time until full feedings was 23.2 hours. These results are not significantly different. When compared with open pyloromyotomy, the laparoscopic approach appears to be equally safe and effective, with superior cosmetic results. The authors believe that laparoscopic pyloromyotomy is an excellent alternative procedure for the management of hypertrophic pyloric stenosis.

Eating↗
PubMed1995

Diagnostic pneumoperitoneum accurately predicts the presence of patent processus vaginalis.

Ninety-four infants with unilateral indirect inguinal hernia underwent repair and diagnostic pneumoperitoneum (DPP). Contralateral groin exploration was performed in all patients including those with a negative DPP result. Thirty-seven (39%) of the 94 patients had a positive DPP result, and 36 of 37 (97%) had a patent processus vaginalis (PPV) on the side contralateral to the clinical hernia. Fifty-seven (61%) of the 94 patients had a negative DPP result, and 54 (95%) of these had no PPV. Female patients had a 1:1 correlation between DPP and PPV. DPP can predict the presence of PPV in the contralateral groin of patients with unilateral hernia with precision and minimizes the need for diagnostic groin exploration.

Child, Preschool↗
PubMed1993

Surgical repair of esophageal perforation due to pneumatic dilatation for achalasia. Is myotomy really necessary?

Esophageal perforation is a rare complication of pneumatic dilatation for achalasia. The few clinical series reported in the literature recommend, under most circumstances, esophageal repair combined with esophagocardiomyotomy. However, the superiority of this technique over repair alone has never been proven. We reviewed our experience, since 1979, with six operative cases of esophageal perforation from pneumatic dilatation for achalasia. After débridement, the esophagus was repaired and, if possible, buttressed with a gastric fundal patch. There was only one late postoperative death due to sepsis and one upper gastrointestinal bleeding complication in our series. Follow-up (1 to 12 years) revealed no dysphagia in any of the five surviving patients and mild gastroesophageal reflux in two. From a review of the literature we found no reports of similarly treated patients experiencing recurrent symptoms of achalasia. In these acutely ill patients, our operative strategy is more feasible than repair and esophagocardiomyotomy and equally effective.

Abscess↗
PubMed1993

Effects of qigong on cardiorespiratory changes: a preliminary study.

Qigong, a special form of breathing exercise, was investigated to examine its effect on cardiorespiratory changes. Ten volunteers (five males and five females) participated in a 20-minute group instructional session for 10 consecutive days before testing of its treatment effects. The testing protocol followed a C1-T-C2 design, where C1, T, and C2 represented the first, treatment, and second control period, respectively. Each period consisted of a 5-minute interval, and thus each testing session consisted of 15 minutes. The results indicated there were no statistically significant differences (p > 0.05) in heart rate or tidal volume for the three 5-minute periods. There was a significant decrease (p < 0.05) in respiratory exchange ratio between T and C2. A significant increase in ventilatory efficiency for carbon dioxide production was found between C1 and T. Statistically significant differences (p < 0.05) were found in the volume of oxygen consumed and carbon dioxide produced, frequency of breath, expired ventilation, and ventilatory efficiency for oxygen produced between the T and the two control periods. This preliminary study of Qigong demonstrates that the subjects were able to learn the technique in a short period of time. The data also suggest that, with an improvement of nearly 20% in ventilatory efficiency for oxygen uptake and carbon dioxide production, this technique may have useful therapeutic value.

Adult↗
PubMed1993

Late recurrence of ductal carcinoma in situ at the cutaneous end of surgical drainage following total mastectomy.

A 40-year-old woman underwent upper outer quadrantectomy breast biopsy which revealed extensive intraductal carcinoma, predominantly comedocarcinoma type, with high nuclear grade. Involved ducts were transected at the edge of the biopsy. Total mastectomy with low axillary lymph node dissection was performed 2 weeks later, showing residual intraductal carcinoma in the upper inner quadrant and no evidence of metastasis. Eight years later, the patient developed two separate foci of recurrent, invasive ductal carcinoma at the exit sites for mastectomy drainage in the subcutaneous skin of the upper abdomen. The mastectomy scar was clinically free of tumor. The biological basis for this unusual sequela of treated intraductal carcinoma is discussed together with its importance for management of early breast cancer.

Axilla↗
PubMed1992

A strategy for resection of Wilms' tumor with vena cava or atrial extension.

Resection of a Wilms' tumor that extends into the vena cava or right atrium results in excellent survival when combined with adjuvant therapy. Preoperative identification of the presence of intravascular tumor thrombus and the level of vascular involvement is essential. It facilitates safe surgical resection, with cardiopulmonary bypass immediately available for retrohepatic and atrial tumors. Six patients with intracaval or intracardiac tumor thrombus were treated over a 5-year period with no perioperative deaths. Preoperative chemotherapy was useful in two patients with extensive tumors and pulmonary metastases. Our results using an integrated management plan suggest that an aggressive surgical approach is justified for this extensive variant of Wilms' tumor.

Algorithms↗
PubMed1991

A MyoD1-independent muscle-specific enhancer controls the expression of the beta-myosin heavy chain gene in skeletal and cardiac muscle cells.

The beta-cardiac myosin heavy chain is the major contractile protein expressed in two sarcomeric muscles of distinct embryologic origins, the ventricular myocardium and slow twitch skeletal muscle. Characterization of the cis-acting regulatory sequences of the human and the rat beta-MHC genes established that their expression in these two muscle types is controlled, at least in part, by common mechanisms involving a muscle-specific enhancer. This enhancer consists of distinct but cooperative subelements that interact with muscle-specific nuclear proteins. In contrast to other muscle-specific enhancers, the beta-MHC gene enhancer is unresponsive, directly or indirectly, to the muscle lineage-determining and muscle gene-transactivating helix-loop-helix factors MyoD and myogenin. A MyoD-binding site in the rat beta-MHC promoter is not required for transcriptional activity in skeletal and cardiac cells, but is necessary for activation in 10T1/2 and CV1 cells transfected with MyoD. In addition, this element is absent from the human beta-MHC promoter. Thus, MyoD and MyoD-related processes are neither required nor sufficient for the expression of the beta-MHC gene either in cardiac or skeletal muscle cells. These observations provide evidence for the existence of myogenic regulatory programs that precede and/or differ from those governed by known myogenic helix-loop-helix transactivators.

Animals↗