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W C Hulbert

Publications and source records attributed to W C Hulbert.

At least 19 recordsLinked to original sources
PubMed1995

Prenatal sonographic diagnosis and subsequent conservative surgical management of bilateral ureteroceles.

Prenatal sonographic diagnosis of ureteroceles usually involves clearly duplicated urinary collecting systems associated with ectopic ureters draining the upper renal moieties. We present an unusual case in which an initial sonographic examination was consistent with bilateral orthotopic ureteroceles in association with bilateral single renal systems. The possibility of single systems raised perinatal considerations unique to this anomaly. Repeat prenatal sonography was suggestive of duplex systems and subsequently confirmed as such by neonatal ultrasound and voiding cystourethrogram. At the age of 1 month, the infant underwent bilateral ipsilateral ureteroureterostomy with conservation of the bilateral dilated upper renal moieties. We discuss the possible pathophysiology underlying the different conflicting sonographic findings and address current management of such lesions.

Adult↗
PubMed1995

Acute scrotal swelling.

Acute scrotal swelling is a potential emergency. The differential diagnosis includes torsion of the testis or one of the testicular appendages, hydrocele, varicocele, trauma, tumor, idiopathic scrotal edema, and Henoch-Schönlein purpura. Imaging studies, such as radionuclide scanning and color Doppler ultrasonography, are helpful in equivocal cases.

Acute Disease↗
PubMed1994

Cryptorchidism.

Explore the source record for details and available documents.

Chorionic Gonadotropin↗
PubMed1993

Screening for urinary tract infection in children with neurogenic bladders.

Urinary tract infections (UTIs) are a frequent and potentially disabling problem for children with neurogenic bladders. Frequent monitoring for UTIs using bacterial culture is expensive and troublesome; thus an inexpensive, dependable screening method is desirable. Three hundred and twenty-nine urine specimens were obtained from 141 children with neurogenic bladders, 86% of whom had meningomyelocele. During the 11-month study period, 43% of the children had at least one positive culture (> or = 100,000 CFU/ml). The results of bacterial culture were compared with the occurrence of signs and symptoms, the presence of reflux and the results of a dipstick test for nitrite and leukocyte esterase. Analysis of the data revealed that (1) UTIs were significantly more common in children with reflux; (2) the presence of signs and symptoms was neither sensitive nor specific (positive predictive value (PPV) = 0.44, negative predictive value (NPV) = 0.84); (3) urinalysis was an unreliable screening tool (PPV = 0.63, NPV = 0.73); and (4) the combination of nitrite and leukocyte esterase was more sensitive and specific than either by itself (combined PPV = 0.69, NPV = 0.88). Children with neurogenic bladders who have reflux or have signs and symptoms should continue regular bacterial cultures, whereas others can be screened dependably using the combined leukocyte esterase and nitrite test.

Adolescent↗
PubMed1992

The predictive value of ultrasonography in evaluation of infants with posterior urethral valves.

Between 1981 and 1989, 28 infants less than 6 months old with posterior urethral valves underwent ultrasound evaluation as part of the initial evaluation at our hospital. The single ultrasound feature that correlated with subsequent renal function was the status of corticomedullary differentiation. The presence of corticomedullary junctions in at least 1 kidney in 17 infants was always associated with a serum creatinine level of 0.8 mg./dl. or less in long-term followup. Of 11 patients with absent corticomedullary differentiation 7 had eventual creatinine levels of greater than 0.8 mg./dl. with 5 of them suffering clinically significant renal insufficiency. An association between vesicoureteral reflux and absent corticomedullary junctions was also found.

Follow-Up Studies↗
PubMed1992

Perforation and intravesical erosion of a ventriculoperitoneal shunt in a child with an augmentation cystoplasty.

Bladder augmentation has evolved into a common method of management in children with a low capacity and/or poorly compliant bladder secondary to a neuropathic condition. We report on a 4-year-old girl with myelodysplasia who presented with sepsis and who had a perforation of the augmented bladder, which was surgically repaired. She returned for evaluation 1 month after she was discharged from the hospital when the distal component of the ventriculoperitoneal shunt was noted to protrude per urethram after clean catheterization. Distal shunt replacement with prolonged bladder drainage successfully resolved this perforation of the augmented bladder. The patient has had no further difficulties. We discuss the diagnosis and management of this case with reference to the current literature regarding complications of augmentation cystoplasty.

Cerebrospinal Fluid Shunts↗
PubMed1992

Toxicology of hydrogen sulfide.

Significant progress has been made in determining the action of sulfide on the primary target organs. It is reasonably clear that sulfide causes both K(+)-channel-mediated hyperpolarization of neurons and potentiation of other inhibitory mechanisms. It is not clear whether these processes are similar to those that occur in anoxia. Changes in perinatal and adult brain neurotransmitter content and release may be related to clinical impairment of cognition. H2S exposures at concentrations below the current occupational limits cause physiological changes in pulmonary function, thus suggesting that asthmatics are at risk. Studies of fetal and neonatal brain tissue have shown an abnormal development, and the long-term consequences of these neuronal changes have not yet been assessed. Finally, new approaches to therapy are required, such as the use of agents that actively remove sulfide from its sites of action. This may prove more useful in preventing some of the long-term adverse sequelae than the use of nitrites and hyperbaric O2, although the latter should be used in cases of pulmonary edema.

Animals↗
PubMed1991

Neonatal capsaicin treatment alters basal pulmonary mechanics and response to methacholine in F344 rats.

Full methacholine dose-response curves were performed on anesthetized tracheostomized Fischer 344 adult rats treated neonatally with capsaicin (50 mg/kg) or with vehicle alone. Capsaicin, the hot extract of pepper, releases substance P (SP) from nonmyelinated sensory nerve endings and causes acute bronchoconstriction and airway microvascular leakiness. Chronic treatment with capsaicin leads to depletion of SP and other tachykinins from afferent C-fibers and can therefore be used as a tool to investigate the contribution of SP innervation to airway responses. The rats (9 controls and 6 treated with capsaicin) were paralyzed with succinylcholine and mechanically ventilated at a constant tidal volume and frequency. Airway resistance (RL) and dynamic compliance (Cdyn) were determined at each dose of methacholine from measurements of volume, flow, and transpulmonary pressure. Capsaicin-treated rats were found to have a significantly reduced baseline RL [0.150 +/- 0.039 (SD) vs. 0.225 +/- 0.050 cmH2O.ml-1.s, P = 0.009] and a correspondingly significantly elevated Cdyn (0.371 +/- 0.084 vs. 0.268 +/- 0.053 ml/cmH2O, P = 0.012). There was no significant difference in sensitivity to methacholine, but the maximal response to methacholine was significantly greater in the capsaicin-treated rats. In terms of RL, the maximal response for capsaicin-treated rats was 6.03 x baseline +/- 0.98 vs. 4.30 x baseline +/- 1.80 (P = 0.05) for controls, and for Cdyn changes the maximal decrease was 5.75 x baseline +/- 1.22 vs. 3.83 +/- 0.69 (P = 0.002). The observed differences in RL and Cdyn coupled with the differences in maximal responses can be attributed to the selective destruction of a subpopulation of pulmonary afferent C-fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗
PubMed1991

The role of polar pili in the adherence of Pseudomonas aeruginosa to injured canine tracheal cells: a semiquantitative morphologic study.

Pseudomonas aeruginosa adheres to respiratory epithelial cells in a highly specific fashion. In order to study the role of P. aeruginosa polar pili in the adherence process we conducted a quantitative morphological electron microscopic examination of P. aeruginosa adherence to SO2 injured canine tracheal cells in vitro. A pilin lacking background strain of P. aeruginosa PAK (BLP2) was constructed using a gene replacement and it in turn was engineered to express either the pilin gene of P. aeruginosa PAO, PAK, or no pilin gene. After 30 minutes incubation of these bacterial strains with injured canine tracheal rings the P. aeruginosa strains expressing pili adhered quantitatively more to the injured tracheal cells than did the pili lacking strains. PAO bearing strains adhered in greater numbers than PAK bearing strains. Healthy tracheal cells did not have any bacteria bound to their surfaces. The bacteria bound to the cilia and lateral edge of the exfoliating tracheal cells. Invasion of tracheal cells by piliated P. aeruginosa bacteria and penetration into the submucosa was also demonstrated. These data confirm the role of pili as important adhesins to injured tracheal cells. The difference in the adherence characteristics of pilin types PAK versus PAO may relate to the differences in the primary structure of these two pilin molecules.

Animals↗
PubMed1991

Testicular imaging.

Clinicians have relied on radionuclide scanning for evaluating acute scrotal pain and on ultrasonography for chronic scrotal pain and anatomic lesions (testicular and paratesticular structures). This review reinforces the utility of these established imaging techniques and also introduces color Doppler ultrasonography as an integral component in the advancement of testicular imaging, particularly in effective and timely diagnosis of spermatic cord torsion. The expanding capability of MR imaging for scrotal disorders is presented.

Color↗
PubMed1990

Color Doppler US in the evaluation of acute scrotal disease.

Twenty-seven patients presented with painful acute scrotal swelling. After a clinical impression was established, all patients underwent diagnostic imaging with color Doppler ultrasound (US). Seven patients underwent surgical exploration for testicular torsion diagnosed with color Doppler US (100% operative confirmation), one underwent radical orchiectomy for treatment of seminoma, and one underwent orchidopexy for treatment of a freely mobile testis. Eighteen patients were treated for nonoperable conditions. Diagnoses made with color Doppler US correlated with final clinical diagnoses in all patients. In 10 of 27 patients (38%), the diagnosis was established at color Doppler US. Until now, nuclear scanning has had a paramount role in the evaluation of equivocal cases of acute scrotal disease. Results show that color Doppler US helps accurately correlate anatomy and perfusion in real time and may prove to be the definitive imaging technique for the diagnostic evaluation of acute scrotal pain or swelling.

Acute Disease↗
PubMed1989

Study of airway epithelial permeability with dextran.

We studied the penetration of fluorescein isothiocyanate (FITC) T-40 dextran into the paracellular spaces in the tracheal mucosa and its appearance in the blood plasma of guinea pigs exposed to cigarette smoke or (controls) breathing room air. Under general anesthesia, the dextran solution was instilled onto the tracheal surface via a tracheotomy tube, arterial blood was sampled serially for 40 min, and then the trachea was fixed by perfusion or immersion. Examination of the tracheal mucosa with light microscopy, with and without epifluorescence, and transmission electron microscopy, revealed dextran in the paracellular spaces in mucosa from experimental animals but not controls. In all control animals, the levels of the dextran in plasma was below the sensitivity of the assay. By contrast, dextran levels in the plasma from the experimental animals fell within the sensitivity range of the assay and increased in blood at a rate of 0.00125 +/- 0.00023 (SE) expressed as a percentage of the instilled dose/min. We conclude that FITC T-40 dextran provides a reliable, fairly simple, fast method for assessing major, but not subtle, changes in paracellular permeability of the tracheal mucosa.

Animals↗
PubMed1989

Effects of SO2 exposure on canine pulmonary epithelial functions.

We examined the effects of a single exposure of high concentrations of sulfur dioxide (SO2) on the pulmonary epithelium in adult dogs over a period of several weeks. Mucociliary tracheal transport rates and alveolar clearance of 99mTc-labeled diethylene triamine pentacetate (99mTcO4-) were measured in vivo, before and immediately after inhalation of 100 ppm or 500 ppm SO2, and then weekly for 3-5 weeks. At the completion of the in vivo studies, tracheal epithelium was studied in Ussing chambers for bioelectric properties (short-circuited current, transepithelial potential difference), nonelectrolyte permeability for calculation of pore sizes, and changes in bioelectric properties following pharmacological manipulations. These tissues were then fixed for scanning electron microscopy studies. Additional dogs were sacrificed for microscopy studies at several time intervals to provide a histological basis for the altered mucociliary transport. We found that despite marked derangement of mucociliary transport caused by damage to the ciliated cells, recovery occurred over a period of several weeks, and alveolar permeability as assessed by the radioaerosol technique did not change. We concluded that the solubility of SO2 and perhaps a more severe damaging effect of SO2 specific on the ciliated cells might be the explanation for the observations.

Administration, Inhalation↗
PubMed1989

The response phase--the first six hours after acute airway injury by SO2 inhalation: an in vivo and in vitro study.

We have identified an airway epithelial response following acute injury that cannot be termed 'repair' or 'regeneration'. It precedes these well characterized events and it is termed the 'response phase'. We tested the hypothesis that for the first 6 h following acute injury to the tracheal mucosa, the initial cellular events of the response phase will continue as in vivo even if the tissue is maintained in vitro in an Ussing chamber. The tracheal mucosa of anesthetized, intubated mongrel dogs was injured by the inhalation of SO2 500 ppm for 1 h (7 dogs); controls (3 dogs) breathed filtered, compressed air for 1 h. 4 dogs were killed, in pairs, at 1 and 6 h after 500ppm of SO2; their tracheas were removed and fixed for microscopic examination. 3 dogs were killed immediately after the SO2 exposure, their tracheas were removed and epithelium isolated from the posterior-membranous sheath was mounted in Ussing chambers in oxygenated, Krebs-Henseleit buffer (8 per dog with aperature area of 1.5 cm2). These tissues (and those from control dogs prepared identically) were fixed after 1 and 6 h incubation for microscopic examination. Epithelial damage was not observed in any controls but was in all tissues exposed to SO2. A wide spectrum of mucosal cell injury during the response phase was observed. The patterns of exfoliation noted were: individual cells, rows (several cells wide) of mucosal cells and entire regions (several hundred microns 2). At 1 h after exposure, in some lesions, the injury is difficult to assess because the tracheal surface was either blanketed in exfoliated cells or appeared in total disarray. By 6 h, the lesions were well defined and large flattened cells (130 microns 2 in surface area) covered the basement membrane in areas where mucosal cells had exfoliated. Some ciliated cells still remained attached at their base in these areas. These were the findings whether the tissues were taken fresh from the animal or have been maintained in Ussing chambers for up to 6 h. These results show that cellular repair of the tracheal epithelium can be studied in vitro during the first 6 h after injury, even if the injury has occurred in situ.

Animals↗
PubMed1988

Protective factors in posterior urethral valves.

Patients with posterior urethral valves may present with or contract renal insufficiency. High intravesical pressure that is transmitted to the upper urinary tract in utero is a likely contributing cause. We have identified 3 anatomical associations with posterior urethral valves that provide a pressure "pop-off" mechanism resulting in preservation of better renal function: 1) the syndrome of posterior urethral valves, unilateral vesicoureteral reflux and renal dysplasia; 2) large congenital type bladder diverticula and 3) urinary extravasation with or without urinary ascites. Followup of 71 boys with posterior urethral valves was sufficient to permit long-term analysis. Serum creatinine was used as an index of renal function and prognosis. Of the 71 boys 20 (28 per cent) had 1 of the 3 protective mechanisms. Only 1 child (5 per cent) had a serum creatinine greater than 1.0 mg. per cent. Of the remaining 51 boys without a "pop-off" mechanism 20 (39 per cent) had serum creatinine greater than 1.0 mg. per cent and 7 had already progressed to renal dialysis and/or transplantation. The difference in serum creatinine was statistically significant (p less than 0.01). Thus, the syndrome of posterior urethral valves, unilateral vesicoureteral reflux and renal dysplasia; large congenital bladder diverticula and urinary extravasation can serve as a "pop-off" mechanism to buffer high pressures in the urinary tract and to lead to the preservation of better renal function in boys with posterior urethral valves.

Child, Preschool↗
PubMed1988

Perforation of the augmented bladder in patients undergoing clean intermittent catheterization.

During urological reconstructive surgery small or large bowel is used to increase bladder capacity or to create a urinary reservoir. In most patients clean intermittent catheterization is necessary for urinary drainage. We report on 4 patients with a sigmoid cystoplasty who perform clean intermittent catheterization and who have experienced a serious long-term complication, urinary reservoir perforation, which was fatal in 1. Two were adolescent girls with myelodysplasia and 2 were prepubertal boys with bladder exstrophy. One patient experienced 2 separate reservoir perforations. Rupture occurred 15 to 48 months (mean 30.2 months) after reconstruction. Diagnosis was made by a static cystogram, which demonstrated extravasation in 2 of 4 patients, and ultrasound. In 2 patients the cystogram was normal. Management included intravenous antibiotics and open abscess drainage in all patients. In patients who have undergone augmentation cystoplasty or continent diversion and in whom abdominal pain and distension develop reservoir perforation should be considered in the differential diagnosis.

Adolescent↗