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Biomedical subjects

J B Fisher

Publications and source records attributed to J B Fisher.

32 records · Page 2Linked to original sources
PubMed1989

Congenital venous web causing subclavian vein obstruction: a case report.

A 7 1/2-year-old black girl had exercise-induced swelling of the left arm and left anterior chest wall caused by a congenital venous web of the subclavian vein. Operative repair was accomplished by venotomy and excision of the web. A venous digital subtraction angiogram obtained on the sixth postoperative day showed unobstructed flow through the operative area. We believe that an isolated, nonthrombotic functional obstruction of the subclavian vein by a venous web has not been previously reported in the English-language literature.

Angiography, Digital Subtraction↗
PubMed1989

Water Transport in the Liana Bauhinia fassoglensis (Fabaceae).

To determine the efficiency of xylem conductance in the liana (woody vine) Bauhinia fassoglensis Kotschy ex Schweinf., we measured hydraulic conductance per unit stem length (measured K(h)), leaf-specific conductivity (LSC = K(h)/distal leaf area), transpiration rate (E), xylem water potential (epsilon), vessel number, and vessel diameter. The measured K(h) was 49% (se = 7%) of the predicted K(h) from Poiseuille's law. The mean LSC for unbranched stem segments was 1.10 x 10(-8) square meters per megapascal per second (se = 0.07). LSCs were much lower (about 0.2) at branch junctions. At midday, with E at 7 x 10(-8) meters per second, the measured drop in epsilon was about 0.08 megapascal per meter along the stems and branches and about 0.27 megapascal in going from stem to leaf. In addition, there was a drop of about 0.20 megapascal at branch junctions as predicted by E/LSC. In diurnal measurements leaf epsilon never dropped below about -1.2 megapascal. For long (e.g. 16 meters) stems, the predicted mid-day drop in epsilon through the xylem transport system might be great enough to have substantial physiological impact.

Journal Article↗
PubMed1989

Routine use of dexamethasone for the prevention of postextubation respiratory distress.

We evaluated the routine use of dexamethasone for the prevention of postextubation respiratory distress by entering 60 ventilated infants into a prospective, randomized, blinded study. Thirty minutes before extubation, 30 infants were given a single dose of intravenous dexamethasone (0.25 mg/kg), and 30 infants received saline placebo. Infants were intubated orotracheally for at least 48 hours following a single intubation and were maintained on low ventilator settings (F10(2) less than 0.35, intermittent mandatory ventilation [IMV] less than 6, positive end-expiratory pressure [PEEP] less than 4) at least 12 hours before extubation. Following extubation, all infants weighing less than 1500 g were routinely placed on nasal continuous positive airway pressure (NCPAP). There was no difference between the two groups in postextubation Downes' score, serum pH, PCO2, or oxygen requirement at 30 minutes, 6 hours, and 24 hours. Respiratory acidosis occurred in one steroid-treated patient and in two placebo-treated infants. Stridor occurred in four infants in each group. No infant developed postextubation lobar atelectasis or required reintubation. We conclude that prophylactic administration of dexamethasone does not improve the immediate postextubation course of infants following a single intubation and that its routine use at the time of extubation is not indicated.

Dexamethasone↗
PubMed1988

Identifying lung overdistention during mechanical ventilation by using volume-pressure loops.

We measured the pulmonary mechanics of 23 mechanically ventilated neonates. Airway pressures, inspiratory and expiratory flows were simultaneously measured. Values for respiratory system mechanics were then derived from these data by using a personal computer and a special software program. Volume-pressure (V-P) loops and respiratory system compliance values were determined for representative mechanical breaths. Twelve infants had normal-appearing V-P loops. Eleven had V-P loops characteristic of lung overdistention, showing decreasing changes in volume with progressive increases in pressure. To quantify this visual observation, we determined the change in compliance during the last 20% of inspiration (C20). We then compared this value to the total compliance value for the entire breath (C) using the ratio C20/C. Mean values for C, C20, and C20/C were compared for the two patient groups. Total respiratory system compliance values were similar. C20 values were decreased in those patients with V-P loops showing overdistention. C20/C values were significantly decreased in those patients with V-P loop evidence of overdistention. Patients with V-P loop evidence of overdistention all had C20/C values less than 0.8. Those with normal-appearing V-P loops all had C20/C values greater than 1.0. The C20/C ratio appears to effectively quantitate visual V-P loop evidence of lung overdistention during mechanical ventilation.

Barotrauma↗
PubMed1985

Neonatal apnea associated with maternal clonazepam therapy: a case report.

A 2750-g female infant was born at 36 weeks' gestation to a 40-year-old woman treated with clonazepam throughout her pregnancy. The infant developed apnea, cyanosis, and hypotonia within a few hours of birth. The mother's serum clonazepam level at delivery was 32 ng/mL; the cord blood level was 19 ng/mL. The infant had no congenital malformations, evidence of infection, or seizures. Clinical episodes ceased by ten days of age. The woman elected to breastfeed; breast milk clonazepam levels were between 11 and 13 ng/mL. She was discharged with a cardiorespiratory monitor. The authors suggest that infants of mothers receiving this agent during pregnancy or while nursing have serum levels measured. Additionally, these infants should be monitored for central nervous system depression or apnea.

Adult↗
PubMed1981

Suction curettage to remove excess fat for body contouring.

We have significantly expanded the use of a lipectomy procedure which heretofore had been restricted to the removal of strictly localized excess fat deposits by curettage through a small incision. By modifying the suction curette and utilizing it for extensive body contouring, we have been successful in correcting relatively major fat deformities without causing any postoperative surgical deformities. All our results to date have been satisfactory. This procedure may be helpful to those surgeons who have been seeking a simplified method for removing excessive fat without extensive scarring. The improvement in body contour is often beyond the preoperative expectations of both the surgeon and the patient.

Adipose Tissue↗
PubMed1980

Origin of the use of subcuticular sutures.

The subcuticular suture has its origins not in the work of one individual but in that of generations of surgeons interested in obtaining the best wound healing possible. In their search for the perfect result they improvised and improved on the ideas of those preceding them. The result is an interesting lesson in medical history and a method of suturing that comes close to achieving the "invisible scar."

History, 19th Century↗
PubMed1979

Ratio of tree branch lengths: The equitable distribution of leaf clusters on branches.

The theoretical optimal ratios of branch lengths, which produce the most equitable distribution (minimum deviation) of leaf clusters in a computer-stimulated branch system, are similar to the observed ratios in real trees of Terminalia. In another study, observed values for branch angles in this species were shown to be similar to theoretical optimal values that produce the maximum effective leaf area. The relationship between these two fundamental parameters of bifurcation and tree geometry and their effect on effective leaf area and distribution of leaves are discussed.

Journal Article↗
PubMed1978

In vitro growth of embryos and callus of coconut palm.

A medium for optimal growth of embryos of Jamaican Tall and Green Malayan Dwarf varieties of coconut palm was developed. The Liquid basal Murashige and Skoog medium was supplemented with coconut milk, IAA and 2IP. Activated charcoal improved embryo growth on agar medium. A single callus line was initiated from solid endosperm and subcultured on basal Schenk and Hildebrandt medium supplemented with 2 mg per 1 NAA. Attempts at inducing organogenesis in the callus were unsuccessful. No vascular tissue was present. The callus was aneuploid with the chromosome number = 8 (normal 2n = 32).

Butyrates↗
PubMedDate not supplied

Evaluation of the perforating veins of the lower extremity using high resolution duplex imaging.

The purpose of this study was to evaluate duplex imaging as a means of assessing perforating veins in patients with longstanding venous stasis ulceration. Thirty patients with nonhealing venous stasis ulcers and twenty normal volunteers serving as controls were evaluated with a standard 8-MHz imaging probe and integrated pulsed Doppler. The internal diameter of perforating veins was measured and perforators were grouped into one of four categories based on functional criteria: competent perforator with venous flow (C); incompetent perforator with venous flow (IC); competent perforator with arteriovenous flow (C-AVC); incompetent perforator with arteriovenous flow (IC-AVC). Sixteen of the patients with ulcers were subsequently studied by ascending venography and in 11 patients, intraoperative identification of perforating veins was made during the Rob procedure. In this subset of patients the vessel was categorized as competent or incompetent regardless of flow signal. There were significant differences in mean perforator diameter between ulcer patients and normal volunteers. Duplex imaging identified 93 perforators and venography a total of 70. In all 16 extremities, duplex imaging made the diagnosis of significant perforating vein incompetence, verified by venography. Intraoperative findings demonstrated an excellent correlation with duplex imaging. We believe duplex imaging to be a promising new modality for evaluation of the perforating veins of the lower extremity.

Adult↗