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Biomedical subjects

W C Hulbert

Publications and source records attributed to W C Hulbert.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1988

Scanning electron microscopy of elastic networks from the bifurcation region of guinea pig carotid arteries.

We isolated the elastic network from the bifurcation region of guinea pig carotid arteries by treatment with hot alkali and examined its adventitial and adluminal components by SEM. The thickness of networks from common and external carotid arteries averaged 87.5 microns (+/- 6.9 SD) and from the carotid sinus averaged 46.8 microns (+/- 2.4 SD). The networks consisted of a mesh of elastic tissue that became a continuous sheet, 2 microns thick, which formed the internal elastic lamina (IEL). The IEL was fenestrated; the perforations varied in number among the vessels (occipital greater than carotid sinus greater than common = external carotid), and some were spanned by delicate elastic fibers. The IEL's adluminal surface was a smooth membranous sheet, which in some specimens bore unidirectional loose fibers, or was composed of tightly fused bundles of uni- or multidirectional fibers. The interior region of the cranial carotid sinus contained unique blister-like structures and dense clusters of fenestrations, together with a honeycomb-like mesh near the ascending pharyngeal artery. The outer, adventitial elastic layer consisted of a network of loose elastic fibers that were fused with the inner layers. We conclude that the structural differences noted among the common and external carotid arteries and carotid sinus are related to the sinus's unique pressure-sensing functions.

Animals↗
PubMed1987

Observations on the fine structure of the baroreceptors and adrenergic innervation of the guinea-pig carotid sinus.

We examined the fine structure of the baroreceptors and the adrenergic innervation of the guinea-pig carotid sinus. The tunica adventitia contained many nerve bundles whose perineuria enclosed unmyelinated nerve fibers, alone or together with myelinated nerve fibers. Baroreceptors, which lay close to elastic and collagen fibers in the adventitia and media, were surrounded by "terminal" cells with ultrastructural features characteristic of Schwann cells and contained inclusions of various types. Morphologic features of the baroreceptors included densely packed mitochondria, osmiophilic lamellated and homogeneous bodies, clear and granular vesicles, lamellar systems, glycogen granules, neurofilaments, neurotubuli, and vacuolated mitochondria. In animals that had been treated with 6-hydroxydopamine, occasional electron-dense endings (or fibers) were observed in the adventitial layer. The baroreceptors in the guinea-pig carotid sinus appear to have most of the morphologic features reported for other species.

Adrenergic Fibers↗
PubMed1987

Canine tracheal injury by neodymium-YAG laser irradiation.

The relationship between endoscopic graded neodymiumyittrium aluminum garnet (Nd-YAG) laser intensity and the magnitude of effects on the tracheal wall was studied in two mongrel dogs. The dogs were anesthetized and graded Nd-YAG laser burns of 50, 100, and 200 Joules (J) were produced on the distal tracheal walls with a laser fiber inserted through a bronchoscope. One dog was killed immediately after injury and the other 24 hours later. At the time of killing, the trachea was excised and prepared for light microscopic (LM) and scanning electron microscopic (SEM) examination. We found that the injury produced by the 50 J intensity beam was confined to the mucosa and submucosa, with no destruction of the tracheal cartilage; by contrast, transmural penetration of the trachea was observed at intensities of 100 and 200 J. These results indicate that a strong correlation exists between laser intensity and the magnitude of the resulting tracheal injury. We suggest that the intensity of a Nd-YAG laser, endoscopically directed perpendicular to the tracheal wall, should not exceed 50 J in order to minimize the risk of perforating the tracheal wall.

Animals↗
PubMed1987

Effects of irradiation on canine tracheal epithelium: a physiological and morphological correlate.

We delivered 20 Gy irradiation in one fraction to a 6 cm segment of trachea in 11 dogs. Tracheal mucous transport was studied before and whenever possible at weekly intervals after irradiation using a gamma camera system and 99m technetium labeled sulfur colloid. Ten of the eleven animals were sacrificed at three different time intervals (1-2, 15-16 and 30-34 weeks) post-irradiation, and the tracheal epithelium removed for studies using Ussing chambers followed by preparation for microscopic analysis. Mucous transport along the length of the trachea was normal before irradiation, but following irradiation it became abnormal in the irradiated zone. Compared to the epithelium from the cranial and caudal segments, the irradiated epithelium had similar bioelectric measurements (potential difference, short-circuit current and resistance) and mannitol permeability. Also, the changes in the bioelectric measurements following indomethacin (10(-6) M) and epinephrine (10(-6) M) used sequentially, were similar in both the control and irradiated tissues. Scanning electron microscopic analysis of the irradiated zone revealed patches of nonciliated epithelial cells among the ciliates. We conclude that irradiation caused a persistent replacement of ciliated cells with nonciliates throughout the entire study period and that this alteration impaired mucous transport but did not affect epithelial ion secretion or barrier function.

Animals↗
PubMed1986

Multidimensional slit-scan detection of bladder cancer. Preliminary clinical results.

A multidimensional slit-scan flow system was developed for the automated recognition of abnormal cells derived from cancer of the uterine cervix and its precursors. It provides great sensitivity in both its ability to recognize cellular abnormality and to deal with the myriad potential causes of false alarms in an automated flow system. While its initial application was the automated recognition of the spectrum of neoplasia in gynecologic cytology samples, a preliminary study was carried out using specimens obtained from the urinary bladder. Cellular material was collected by bladder irrigation and stained with the fluorochrome acridine orange. One hundred fifty-three bladder irrigation specimens, including 115 abnormal specimens containing cells derived from neoplastic lesions of the bladder epithelium, were analyzed. For the purposes of this study, abnormal specimens from the urinary bladder included specimens containing cells derived from the following lesions of the urothelium: dysplasia (atypical hyperplasia), carcinoma-in-situ, and transitional cell carcinoma, grades 1-3. Approximately 50,000 cells were analyzed for most specimens. Of the 38 presumed normal specimens (specimens containing only normal urothelial components), four were instrument classified abnormal. For the 69 specimens containing cells derived from transitional cell carcinoma, grade 1, 1-2, 2, 66 were correctly classified as abnormal while three were classified as normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma in Situ↗
PubMed1986

Effects of sulfur dioxide on pore populations of canine tracheal epithelium.

The bioelectric and barrier properties of the tracheal epithelium in nose-breathing dogs and in dogs that had been exposed for 75 min to compressed air or to two high concentrations of SO2 were measured and compared. We also studied tissues that had been treated with chloroform. Based on a model of restrictive diffusion we demonstrated heteropores (6 and 250 A) in the control tissues. Bioelectric changes due to 100-ppm SO2 were minimal. After exposure to 500 ppm SO2, adverse changes in the bioelectric properties were focal; they were marked in 8 out of 12 animals but were less striking in the other 4. Nonelectrolyte permeability increased with an increase in SO2 concentrations. Small pores were still present in the tissues severely affected by SO2 but they were absent in chloroform-treated tissues. Scanning electron microscopy of tissues from animals exposed to 500 ppm SO2 showed that in the same dog tissue appearance varied from normal to one of repair (normal bioelectric properties) or one of marked exfoliation of ciliated cells (abnormal bioelectric measurements).

Animals↗
PubMed1985

Hyperreninemic hypertension secondary to radiation nephritis in a child.

Radiation injury to the kidney, first reported almost eighty years ago, may vary from subclinical changes in renal blood flow or enzyme activity to clinically significant hypertension and/or renal failure. A child with radiation-induced hyperreninemic hypertension was cured by nephrectomy. The microscopic, subclinical, and clinical changes of irradiation injury are reviewed. The etiology of radiation-induced hypertension, methods of radioprotection, and early detection of radiation renal damage are discussed.

Child↗
PubMed1985

Appendiceal abscess masquerading as acute urinary retention in children.

Two boys with acute urinary retention were found to have a persistent pelvic mass after bladder decompression. Evaluation in each disclosed a large pelvic abscess secondary to a ruptured appendix. The diagnosis of appendicitis may be difficult and appendiceal abscess presenting with acute urinary retention in children has been reported previously in only 7 instances. History, physical examination, laboratory studies, and radiographic and ultrasonic evaluations should lead to the correct diagnosis, and surgical intervention restores normal voiding.

Abscess↗
PubMed1985

Peritonitis and abdominal free air due to intraperitoneal bladder perforation associated with indwelling urethral catheter drainage.

Perforation of the bladder related to long-term indwelling Foley catheter drainage is a rare and serious complication. We report 2 cases of bladder perforation leading to generalized peritonitis and free intraperitoneal air. These cases re-emphasize the importance of considering bladder perforation in the differential diagnosis of the acute abdomen and of performing a complete abdominal exploration when the site of perforation is not easily detectable.

Abdomen↗