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Biomedical subjects

J D Fischer

Publications and source records attributed to J D Fischer.

15 recordsLinked to original sources
PubMed2003

A pesticide runoff model for simulating runoff losses of pesticides from agricultural lands.

An integrated modeling system was developed to predict runoff losses of pesticides from agricultural lands. The system is an integration of a mathematical model, a database system, and a geographic information system. Information on soil type, land use, land slope, watershed boundaries, precipitation, pesticide usage, as well as physical and chemical properties of pesticides have been input to a GIS, managed through a database, and used for further modeling studies. The modeling outputs were in turn put into the database, such that runoff patterns along with pesticides losses could be further simulated by using a database management system. The final results could then be visualized through GIS. The developed modeling system was applied to the Kintore Creek Watershed, Ontario, Canada, for simulating losses of atrazine from agricultural lands. A water quality monitoring project was carried out from 1988 to 1992 in the watershed to detect conditions of surface water pollution due to the use of pesticides. The modeling outputs were verified through the monitoring data, demonstrating reasonable prediction accuracy. The result indicated that the model provides an effective means for forecasting pesticide runoff from agriculture lands.

Agriculture↗
PubMed2001

Pediatric thoracic trauma.

OBJECTIVE: A retrospective analysis of the medical records of children up to 12 years of age inclusive, who sustained thoracic injuries during a 6-year period. METHODS: Ninety-one children were treated at King Fahad National Guard Hospital, Riyadh from January 1993 through December 1998. The clinical data included age, sex, mechanism of injury, associated injuries, pediatric trauma score, treatment and mortality. RESULTS: Eighty-seven children (96%) had injuries from blunt trauma and 4 from penetrating injuries. Of the blunt trauma cases, 82 children sustained motor vehicle accident related injuries, 62 as pedestrians and 20 as passengers. Penetrating thoracic injuries occurred in 4 children: 1 stab wound and 3 gunshots. The most frequent thoracic injuries were pulmonary contusion (70), pneumothorax (32), fractured rib (20) and fractured clavicle (18). Extrathoracic injuries included head (45), abdominal (41) and skeletal (26). Thoracotomy was required in only 1 child, laparotomy being necessary in 9 children for intraabdominal injuries. Tube thoracostomy was required in 33 children. Nine children died from motor vehicle accident related fatal head and neck injuries, 8 as pedestrians all with a pediatric trauma score < or = 6. CONCLUSION: Thoracic injuries in children below 12 years of age are usually from motor vehicle accident related blunt trauma. Pulmonary contusion and pneumothorax are the most common thoracic injuries. Most thoracic injuries can be managed either conservatively or by tube thoracostomy. Thoracic trauma in children is an indicator of multisystem injury with head injury being the most common cause of mortality.

Accidents, Traffic↗
PubMed2000

Comparison of zafirlukast (Accolate) absorption after oral and colonic administration in humans.

PURPOSE: This study characterized the gastrointestinal (GI) absorption of zafirlukast after oral and colonic administration in humans. METHODS: Five healthy subjects received zafirlukast solution (40 mg) orally and via an oroenteric tube into the colon in a randomized, crossover fashion. Two additional subjects were dosed into the distal ileum. Serial blood samples were obtained and plasma concentrations were quantitated by HPLC. RESULTS: Mean +/- SD pharmacokinetic parameters after oral vs. colonic administration were: AUC infinity of 2076 +/- 548 vs. 602 +/- 373 ng x h/mL, respectively, and Cmax of 697 +/- 314 vs. 194 +/- 316 ng/mL, respectively. Mean colon:oral AUCalpha and Cmax were 0.29 and 0.30, respectively. Median tmax values were 2.0 and 1.35 hr after oral and colonic administration. First-order absorption rate constants (Ka and Kac) were estimated from a two-compartment model with first-order elimination. Kac:Ka was <0.5 in 4 of the 5 subjects dosed in the colon. CONCLUSIONS: Zafirlukast was absorbed at multiple sites in the GI tract. The rate and extent of zafirlukast absorption was less after colonic than oral administration. Zafirlukast was significantly absorbed in the distal ileum. This study demonstrated that gamma scintigraphy, digital radiography, and fluoroscopy can be used to track the movement and confirm the location of the oroenteric tube in the GI tract.

Administration, Oral↗
PubMed1998

Bronchobiliary fistula: a case report.

Fewer than 20 cases of bronchobiliary fistula have been reported in the literature. In this report a newborn female infant was referred for investigation of gastroesophageal reflux. Upper gastrointestinal endoscopy and 24-hour pH monitoring revealed severe reflux. A fundoplication was carried out. In the immediate postoperative period bile was noticed coming from the endotracheal tube. Bronchoscopy revealed an abnormal opening just to the left of the carina. Fistulography and HIDA scanning confirmed the presence of a bronchobiliary fistula. A right thoracotomy was used to divide the fistula. The child made an uncomplicated recovery. Pathological examination of the excised specimen demonstrated tissue most consistent with an esophageal origin.

Biliary Fistula↗
PubMed1995

Gastroschisis: a simple technique for staged silo closure.

In conjunction with the Neonatology Department at Loma Linda University Children's Hospital, a new protocol has evolved for the management of infants with gastroschisis, which obviates both risks associated with primary and staged silo closure. After stabilization of the infant in the neonatal intensive care unit, under sterile conditions, a 5- or 7-cm SILASTIC silo with a spring-loaded ring is placed over the exposed viscera, under the fascial defect. No sutures are required. A fentanyl drip is given, and the bowel is gradually reduced over the next few days. The transparent material of the silo allows for continuous monitoring of the condition of the bowel. Second-stage closure in the operating room is performed using a purse-string suture in the fascia to create a pseudoumbilicus. From October 1992 to April 1994 the authors managed 10 infants using this protocol. The results are compared with those of infants with gastroschisis treated at the same institution between August 1982 and June 1993. Outcome parameters to be compared include time until closure, time on ventilation, days of total parenteral nutrition, time until start of oral feeding, time until toleration of full-volume oral feeding, and time until discharge. The authors conclude that silo closure in the neonatal intensive care unit is simple, quick, and effective. It eliminates multiple trips to the operating room, allows the natural accommodation of the bowel into the abdominal cavity with little edema and minimal vascular compromise, and has become the authors' treatment of choice for infants with gastroschisis.

Abdominal Muscles↗
PubMed1995

Pediatric laparoscopic splenectomy.

Laparoscopic surgery is becoming widely accepted as an alternative to conventional procedures. It is becoming more and more evident that laparoscopic techniques can be applied successfully to pediatric patients. Advantages of these techniques include less postoperative pain, decreased ileus, fewer pulmonary complications, and shorter hospital stays. Elective splenectomy for hematologic disease or for staging of Hodgkin's lymphoma also appears to be amenable to laparoscopic techniques. This report details 12 consecutive splenectomies successfully performed laparoscopically since July 1993. No case required conversion to laparotomy. Each case was reviewed with respect to operative time, estimated blood loss, identification of accessory spleens, time until full oral intake, analgesia requirements, and length of stay. Factors contributing to morbidity such as ileus, pulmonary complications, and would infections were evaluated. Documentation was also reviewed for late sequelae such as intestinal obstruction and incisional hernias. These patients were compared with 20 consecutively treated patients who underwent open splenectomy in the period immediately preceding the use of laparoscopic splenectomy. Laparoscopic splenectomy, in the authors' experience, is a safe alternative to open splenectomy, has few complications, is cost effective, and has been well accepted by patients and families.

Adolescent↗
PubMed1995

Esophagotomy for incarcerated esophageal foreign bodies.

Less than 1% of esophageal foreign bodies are irretrievable by endoscopic techniques. Incarcerated esophageal foreign bodies require esophagotomy for removal. A retrospective study was conducted to determine the incidence, predisposing factors, and optimal treatment of incarcerated esophageal foreign bodies. Four of 815 patients (0.5%) with esophageal foreign bodies required esophagotomy for foreign body removal. Two predisposing factors for incarceration were identified, and these factors were related to patient age. Two infants had neglected esophageal foreign bodies that partially migrated through the esophageal wall. In two adults, foreign body size and sharpness were responsible for incarceration. One cervical and three thoracic esophagotomies were done. One thoracic esophagotomy suture line dehiscence occurred. Occult foreign body pressure necrosis may be a factor in esophagotomy suture line leakage. Care is required in esophagotomy closure. Principles established for repair of esophageal perforations are also applicable to esophagotomy closure.

Adult↗
PubMed1994

A variant of Poland's syndrome.

A case of Poland's syndrome--the association of congenital thoracic abnormalities with ipsilateral syndactyly--in a newborn infant is described. The infant demonstrated unusual manifestations of the syndrome: there was extension of the liver through the chest, and there was absence of a whole arm rather than hypoplasia and syndactyly. The authors describe the investigation and treatment of this infant, and they discuss the diversity of findings in Poland's syndrome.

Dextrocardia↗
PubMed1992

Routine omission of nasogastric intubation after gastrointestinal surgery.

The need for routine nasogastric-tube decompression after gastrointestinal surgery has been challenged repeatedly for several years. To determine whether nasogastric intubation can be omitted routinely, 101 consecutive patients who underwent gastrointestinal surgery were managed prospectively without nasogastric tubes. Excluded were patients with complete bowel obstruction and those who required prolonged endotracheal intubation. These patients were compared with 101 retrospective controls who had nasogastric decompression routinely. There were four protocol violations in the prospective group (nasogastric tubes were left in place postoperatively) and one in the retrospective group (no nasogastric tube postoperatively), leaving 97 and 100 patients, respectively, for follow-up. The mean duration of hospitalization in comparable patients was 10.6 days in patients without decompression and 11.9 days in those with routine decompression. Subsequent nasogastric-tube insertion was required in nine patients who did not undergo routine decompression, compared with two patients who had routine decompression. There were no statistically significant differences in the rates of anastomotic leaks, wound disruptions and pulmonary or other complications between the two groups. The authors conclude that nasogastric decompression can be safely omitted as a routine part of postoperative care after gastrointestinal surgery.

Digestive System Surgical Procedures↗
PubMed1990

Characteristics of participants in a large group awareness training.

A study was conducted to assess the psychosocial characteristics of individuals who become involved in large group awareness training (LGAT) programs. Prospective participants in The Forum, which has been classified as an LGAT, were compared with nonparticipating peers and with available normative samples on measures of well-being, negative life events, social support, and philosophical orientation. Results revealed that prospective participants were significantly more distressed than peer and normative samples of community residents and had a higher level of impact of recent negative life events compared with peer (but not normative) samples. Prospective participants also held preparticipation values more similar to those espoused by the LGAT than peer or normative samples, and the three groups failed to be distinguished by their levels of social support. The implications of the findings are considered for understanding participation in LGATs and other self-change promoting activities.

Analysis of Variance↗