Transepithelial transport of tyramine across filter-grown MDCK cells via a poly(D-lysine) carrier

In order to investigate the advantage of using membrane-adsorptive carriers to mediate drug transport across epithelial tissue, we have prepared disulfide- and thioether-linked conjugates of tyramine (tyn) as a model drug to a cationic, nondegradable carrier, poly(D-lysine) (PDL). The transport properties were evaluated using microporous filter-grown Madin-Darby canine kidney (MDCK, strain I) epithelial cells, and we have determined that: (a) the [125I]tyn-SS-PDL conjugate predominantly transported [125I]tyn in the apical-to-basal direction (20-fold greater transport vs. basal-to-apical); (b) [125I]tyn-SS-PDL elicits a 10-fold greater degree of [125I]tyn transport than [125I]tyn-S-PDL, thus demonstrating the importance of the reducible disulfide linkage for [125I]tyn transport to occur; (c) 125I-radioactivity recovered in the basal media was determined to be 95% [125I]tyn-containing small molecules, thus demonstrating the release of [125I]tyn from its PDL carrier; (d) the apical addition of an anionic species, heparin, completely blocks apical-to-basal transport of [125I]tyn, indicating the importance of PDL-mediated binding to the apical membrane for transport to occur; (e) apical-to-basal transport proceeds via non-lysosomal pathways, as lysosomal inactivation by NH4Cl exposure does not inhibit transport, and (f) the addition of a membrane-impermeable inhibitor of disulfide reduction, bisdithionitrobenzoic acid (DTNB), to the apical media inhibits transport by approximately 70%, indicating the importance of apically-localized disulfide reducing reactions for transport of [125I]tyn. Pulse-chase studies indicate that there is no paracellular leakage of conjugate, and the ratio of recycled:membrane-associated:transported [125I]tyn fragment following chase is 4:2:1.

Two-stage repair for severe hypospadias

In 39 patients a 2-stage modified Belt-Fuqua repair was performed for severe hypospadias and chordee. Patient age at initial surgery averaged 2 years and stage 2 was done 7 months later. Testosterone was given before stage 1 to 22 patients (56%) and before both stages to 13 (33%). Of 5 patients with intersex 2 had mixed gonadal dysgenesis, 1 was a true hermaphrodite and 2 were 46 XX male subjects. The preoperative meatal location was subglanular in 9 cases, mid shaft in 8, proximal shaft in 2, penoscrotal in 15 and perineal in 5. Those with subglanular meatus had hypoplastic distal urethras and severe chordee. A dorsal Nesbit procedure for chordee correction was done in 24 cases (62%). Neourethral length ranged from 3 to 7 cm. (average 4 cm.) and average followup was 16 months. Neourethral diverticula developed in 8 cases (21%) and they were repaired uneventfully an average of 7 months (range 2 to 24) after stage 2. Minor urethral strictures (3 distal and 4 proximal) were treated with a single visual internal urethrotomy and there was 1 (2.5%) urethrocutaneous fistula. All children had excellent cosmetic and functional outcomes. A staged approach allows for cosmetic reconstruction of the glans and mucosal collar during stage 1 and offers 2 opportunities to augment penile size with testosterone. Bladder or buccal mucosal grafts are avoided since the prepuce is always adequate. There are no hypospadias deformities, penile shaft torsion or asymmetry. Fistula formation is minimal and strictures are minor. The 2-stage repair remains a safe, reliable alternative for boys with severe hypospadias.

The effect of terazosin on bladder function in the spinal cord injured patient

We prospectively studied the effect of terazosin on bladder compliance in 12 spinal cord injured patients. All study patients had demonstrated previously poor compliance despite clean intermittent catheterization and maximum anticholinergic therapy. Patients were started on 5 mg. terazosin nightly for 4 weeks. They were evaluated with a history, physical examination, symptom score, and synchronous cystoscopy and cystometry before, during and after terazosin therapy. Detrusor compliance improved in all patients during the treatment phase. The change in bladder pressure and the safe bladder volume were statistically and clinically significant. Patients also reported fewer episodes of incontinence and dysreflexia. The improvement in compliance and continence suggests that in the spinal cord injured patient terazosin may have an effect on alpha receptors in the detrusor muscle or central effects and that improved compliance is not due to decreased outlet resistance.

Intravesical instillation of gentamicin sulfate: in vitro, rat, canine, and human studies

OBJECTIVE

Intravesical instillation of gentamicin sulfate has been used empirically as prophylaxis and to treat bacilluria in spinal-cord-injured patients undergoing clean intermittent catheterization. To assess the risks of absorption and the effects of storage conditions on antimicrobial potency, a series of studies were conducted.

METHODS

Four studies were carried out: (1) An infected fulgurated rat bladder model was created to determine the effects of inflammation and infection on absorption. (2) A canine model with bilateral vesicoureteral reflux and elevated bladder pressures (> 40 cmH2O) assessed the effects of reflux and storage pressure. (3) The effects in patients with associated conditions including renal transplantation, myelomeningocele, vesicoureteral reflux, and bladder augmentation, were analyzed. (4) To determine the effects of storage conditions, solutions of gentamicin sulfate (480 mg gentamicin sulfate in 1 L 0.9% NaCl) were made that controlled for pH, storage temperature, and duration.

RESULTS

(1) Increased absorption was found in 43 percent of rat serum samples. (2) None of the dogs demonstrated measurable absorption. (3) None of the patients likewise had measurable absorption. (4) All solutions were equally potent when tested against a panel of common urinary pathogens. Storage up to two months at room temperature without alkalinization had no effect on potency.

CONCLUSIONS

Instilled intravesical gentamicin sulfate has a low risk of absorption and is highly effective. Severe bladder inflammation can increase transvesical absorption. It has prolonged stability without special storage conditions and should be considered as a route of prophylaxis in patients who perform intermittent catheterization.

Influence of the Gas-Water Interface on Transport of Microorganisms through Unsaturated Porous Media

In this article, a new mechanism influencing the transport of microorganisms through unsaturated porous media is examined, and a new method for directly visualizing bacterial behavior within a porous medium under controlled chemical and flow conditions is introduced. Resting cells of hydrophilic and relatively hydrophobic bacterial strains isolated from groundwater were used as model microorganisms. The degree of hydrophobicity was determined by contact-angle measurements. Glass micromodels allowed the direct observation of bacterial behavior on a pore scale, and three types of sand columns with different gas saturations provided quantitative measurements of the observed phenomena on a porous medium scale. The reproducibility of each break-through curve was established in three to five repeated experiments. The data collected from the column experiments can be explained by phenomena directly observed in the micromodel experiments. The retention rate of bacteria is proportional to the gas saturation in porous media because of the preferential sorption of bacteria onto the gas-water interface over the solid-water interface. The degree of sorption is controlled mainly by cell surface hydrophobicity under the simulated groundwater conditions because of hydrophobic forces between the organisms and the interfaces. The sorption onto the gas-water interface is essentially irreversible because of capillary forces. This preferential and irreversible sorption at the gas-water interface strongly influences the movement and spatial distribution of microorganisms.

Ureteral reimplantation in infants

Between 1984 and 1990, 30 infants (46 ureters) 8 weeks to 6 months old (mean age 4 months) underwent ureteral reimplantation. Weight at operation ranged from 4.9 to 9.5 kg. (mean 6.9). Underlying abnormalities were primary vesicoureteral reflux (28 ureters), primary ureterovesical junction obstruction (11), ectopic ureterocele (4) and ectopic ureter (3). Patients with reflux underwent surgery because of high grade reflux (grade IV or V) or breakthrough infection. Infants with primary ureterovesical junction obstruction underwent obstructive diethylenetriaminepentaacetic acid diuretic renograms. Reimplantations performed included 44 Glenn-Anderson advancements, 1 Cohen cross-trigonal advancement and 1 Politano-Leadbetter procedure. Of the ureters 30 (65%) were tapered intravesically. Ureteral stents were used in all instances. Transient ureteral obstruction developed in 2 children following stent removal and 1 required temporary percutaneous nephrostomy drainage. No permanent ureterovesical obstruction was noted in any patient. Followup at 18 months revealed no postoperative reflux in 43 of 46 ureters (93%). One infant required repeat reimplantation to correct a vesicoureteral fistula and the remaining 2 patients (2 ureters) with low grade reflux (grade I and II) are being observed. Surgery was successful in 27 of 30 tapered ureters (90%) and in all 16 of the nontapered ureters (100%). While the majority of infants with ureterovesical junction abnormalities may be observed, some may require surgery. Reimplantation, when necessary in this age group, can be performed with a high degree of success and diverting procedures such as vesicostomy or ureterostomy can be avoided.

Clinical assessment of urethral sphincter function

Measurements of urethral pressures, such as maximum urethral pressure, are widely believed to have relevance in the management of urinary incontinence despite evidence to the contrary. In this study maximum urethral pressure and the abdominal pressure required to cause stress incontinence were measured in 125 women with stress incontinence. In women the abdominal pressure required to cause stress incontinence was unrelated to maximum urethral pressure. These findings indicate that maximum urethral pressure has little relationship to urethral resistance to abdominal pressure. In the 9 children with myelodysplasia we compared the detrusor pressure with the abdominal pressure required to induce urethral leakage. These values also were quite different, indicating that as far as the urethra is concerned abdominal pressure and detrusor pressure are not equivalent forces.

Stress leak point pressure: a diagnostic tool for incontinent children

The stress leak point pressure is the lowest bladder pressure at which leakage occurs during prompted increases in intra-abdominal pressure. The stress leak point pressure is distinct from the simple bladder leak point pressure and can be determined using simple urodynamic equipment without fluoroscopy. In 15 incontinent girls and boys 2.5 to 15 years old the mean stress leak point pressure was 54.7 cm. water (range 11 to 100), whereas the mean leak point pressure was 19.9 cm. water (range 5 to 50, paired t test p < 0.0001). The stress leak point pressure is a useful diagnostic tool that provides specific data on bladder neck and proximal urethral function.

Distal intussusception of processus vaginalis: a cause of acute hydrocele

Acute obstruction of a patent processus vaginalis occurred in two boys, mimicking incarceration of an inguinal hernia. In fact, obstruction was caused by an intussusception of the processus vaginalis forming an intussuscipiens that occluded the hernia sac. This lesion, described previously in 1896 and in 1974, is one of the mechanisms by which an asymptomatic hernia or hydrocele becomes acutely symptomatic.

The management of meatal obstruction due to Kaposi's sarcoma of the glans penis

Kaposi's sarcoma involving the glans penis was first described in 1902, with a subsequent report of meatal disease in 1943. With the recognition of the acquired immunodeficiency syndrome, genital lesions are becoming more frequently reported, with 51 cases cited in the literature. To date only 4 additional cases of meatal or fossa navicularis involvement have appeared in the literature, 3 of which described difficulty with micturition. We report a case of Kaposi's sarcoma involving the urethral meatus resulting in documented outflow obstruction, relieved with simple urethral serial dilation performed on an outpatient basis followed by intermittent obturation. We believe that this therapy represents a low risk, cost-effective treatment modality aimed at resolution of symptoms and alleviation of a potential source of infection in the patient with the acquired immunodeficiency syndrome.

Primary mucinous adenocarcinoma of renal pelvis in solitary pelvic kidney

Mucinous adenocarcinoma of the renal pelvis is a rare tumor. We report the case of a fifty-three-year-old man with this unusual cancer and review the literature. Usual features of this tumor include long duration of symptoms, an association with calculi and hydronephrosis, and a preoperative appearance of an inflammatory condition.

Detection of non-palpable prostate cancer. A mathematical and laboratory model

Prostate cancer is currently the most commonly diagnosed cancer among males in the United States. As technology improves and the search for this enigmatic condition intensifies, we are detecting greater numbers of non-palpable tumours. These tumours are generally treated aggressively, given the uncertainty of their behaviour, but this approach may be over-zealous for small volume disease. The likelihood of detecting any cancer volume can be derived from Bayes' theorem of conditional probability. A laboratory model using coloured clay was created to contrast tumour volumes of 2.5, 5 and 20% (n = 75). Six random systematic biopsies were taken from each model in a blind fashion; 36% of the 2.5%, 44% of the 5% and all of the 20% models had at least 1 positive biopsy. Twenty-two of the 25 models representing 20% tumour had 3 or more biopsy cores positive. These data suggest that low volume disease with low biological potential will be found by random biopsy as the mathematical probability predicts. The high incidence of occult prostate cancer in the older population makes this a worrying observation. Also, and perhaps more important, there is a direct correlation between the volume of disease and the number of positive biopsies. This correlation is easily seen in both models and may allow for an estimation of tumour volume. This ability to estimate tumour volume may be a useful clinical tool that helps to guide therapy and assess prognosis.

Retroperitoneal neurogenous choristoma

A 6-year-old girl with urinary complaints underwent ultrasonography, which revealed a retroperitoneal cystic mass adjacent to the left kidney. Computerized tomography did not demonstrate whether the mass was an adrenal cyst or a duplicated upper pole segment. Exploration revealed a neurogenous choristoma, which is a collection of histologically normal tissue that is ectopically situated. We believe that this is the first report of this rare entity occurring in the retroperitoneum.

Urinary tract status of patients with neurogenic dysfunction presenting with upper tract stone disease

We treated 71 patients with neurogenic vesical dysfunction between September 1983 and June 1990 for upper tract stones. We studied these patients to determine the time course of stone development and the presence of associated urological abnormalities. There were 44 male and 27 female patients 6 to 72 years old. Lower urinary tract dysfunction resulted from spinal cord injuries in 34 patients (48%), myelodysplasia in 19 (27%), multiple sclerosis in 12 (17%) and other diagnoses in 6 (8%). Of 71 patients 21 (30%) were managed by an ileal loop, 12 (17%) by a Foley catheter, 10 (14%) by a suprapubic tube, 10 (14%) by ureterostomy, 5 (7%) by vesicostomy, 8 (11%) by intermittent catheterization, and 5 (7%) by diaper, Créde's voiding or condom catheterization. Stone disease developed within 1 to 22 years. Patients with an indwelling catheter or supravesical diversion fared worse than those managed by intermittent catheterization or vesicostomy; they had higher rates of renal unit loss, renal parenchymal damage, decreased renal function, hydroureter, and staghorn and bilateral calculi. All of the listed methods of management were contemporaneous, suggesting the continued use of methods proved to be associated with upper tract deterioration.

Brefeldin A enhances receptor-mediated transcytosis of transferrin in filter-grown Madin-Darby canine kidney cells

The effects of brefeldin A (BFA) on transferrin (Tf) transcellular transport, Tf receptor (TfR) distribution, and TfR-mediated endocytosis in filter-grown Madin-Darby canine kidney (MDCK) cells were studied. BFA (1.6 micrograms/ml) markedly enhanced the transcytosis of 125I-labeled Tf (125I-Tf) in both apical-to-basal and basal-to-apical directions; yet, BFA did not enhance the transcytosis of either native horseradish peroxidase (HRP) or membrane-bound HRP-poly(L-lysine) conjugates. Furthermore, this enhanced transcytosis of 125I-Tf was abolished either by competition with excess unlabeled Tf or by incubation at temperatures less than or equal to 25 degrees C. In addition, BFA treatment to MDCK cells: (a) increased 125I-Tf specific binding to the apical membrane and decreased 125I-Tf specific binding to the basal membrane; (b) decreased TfR recycling at the basolateral membrane; (c) altered the apical/basolateral distribution of TfRs in favor of the apical side; and (d) markedly increased 59Fe extraction, but not transcytosis, from apically endocytosed 59Fe-loaded Tf. These effects are consistent with a model in which BFA alters the traffic pattern of internalized Tf by decreasing basolateral TfR recycling, while diverting the nonrecycled fraction to the apical side of the cell. Our results indicate that, unlike the reported inhibition of polymeric IgA transcytosis (Hunziker, W., Whitney, J. A., and Mellman, I. (1991) Cell 67, 617-627), BFA can enhance the transcytosis of Tf in MDCK cells. Thus, by altering the intracellular traffic of ligand-receptor complexes, BFA can elicit either a decrease or an increase in transcytosis depending on the nature of the intracellular receptor processing.

The treatment of urinary incontinence in children using glutaraldehyde cross-linked collagen

Periurethral injection of polytetrafluoroethylene (PolyTef) paste has been used to correct urinary incontinence for 2 decades. The controversy over distant migration of the paste has led to an interest in alternative materials particularly for the pediatric patient. Glutaraldehyde cross-linked collagen, derived from bovine dermal collagen, is effective in treating urinary incontinence in adults. Eight children with structural urinary incontinence underwent glutaraldehyde cross-linked collagen injection. Fluorourodynamic studies preceded and followed the injections. An average of 10.9 cc glutaraldehyde cross-linked collagen was injected per treatment (range 2.5 to 20). The number of injections per child ranged from 1 to 6 (mean 2.1) and followup averaged 13.75 months (range 6 to 33). Overall, 88% of the patients were cured or improved: 5 (63%) became continent, 2 were improved and 1 had no effect.

CDC14 of Saccharomyces cerevisiae. Cloning, sequence analysis, and transcription during the cell cycle

We have cloned, mapped and sequenced the complete CDC14 gene of Saccharomyces cerevisiae and characterized its transcription during the cell cycle. CDC14 was found within a 3.5-kilobase pair XhoI-XbaI fragment of chromosome VI. The DNA sequence reveals an open reading frame capable of encoding a 423-amino acid polypeptide. Protein sequence comparisons through the Prosite, GenBank and EMBL databases allowed us to identify a conserved protein tyrosine phosphatase active site in the encoded CDC14 protein beginning at amino acid 153. Disruption demonstrates that CDC14 is an essential gene. The level of the CDC14 transcript appears to be weakly cell cycle-regulated and has a periodicity which lags approximately 15 min behind histone HTB1 mRNA accumulation levels. DNA sequence analysis has identified a region within the CDC14 promoter which bears a striking resemblance (15 out of 21 base pairs identity) to the cell cycle regulation region of the promoter of the histone H2A1-H2B1 (HTA1-HTB1) gene pair. The cell cycle regulation sequence is responsible for the periodic accumulation and hydroxyurea sensitivity of the histone HTA1-HTB1 message. However, unlike histone mRNA, which is repressed upon hydroxyurea arrest, CDC14 mRNA appears to be unaffected. This suggests that CDC14 and histone genes are regulated by different mechanisms during the cell cycle. Furthermore, superhelical density measurements suggest that CDC14 is not involved in nucleosome assembly.

Study of radiation dosage in esophageal carcinoma

A series of 221 esophageal carcinoma patients admitted from 1983 to 1984 for radiotherapy was randomised into two groups. Group A was given 50 Gy/5 wk, 111 patients and Group B 70 Gy/7 wk, 110 patients. Three in group A and 11 in Group B did not complete their treatment due to adverse reactions. The 5-year survival rates of Groups A and B were 16.7% and 17.2% (P greater than 0.5). Because of the absence of excellent results and higher incidence of discontinuation of therapy in the 70 Gy group, the authors believe that the high dose regimen is not warranted in esophageal cancer.

Accelerated hyperfractionation radiotherapy in esophageal cancer. An analysis of 172 cases

Between February 1989 and May 1983, 172 patients with esophageal carcinoma were given radiotherapy. They were randomly assigned to an accelerated hyperfractionation group and routine fractionation group. There was no statistically significant length of survival difference between these two groups at 1, 3 and 5 years. Therefore accelerated hyperfractionation is useful for its economy of duration and cost.

Racial differences in social support and mental health in men with HIV infection: a pilot study

The mediating role of social support in the mental health and behaviours of persons coping with life-threatening chronic illness is of potentially great importance in determining the quality of life of persons with HIV infection (PWHs). As part of a biracial pilot study of the ways black and white men manage the stresses of sexually acquired HIV infection, we have examined the relationship between social support and mental health and behaviours. Forty homosexual/bisexual men (20 white and 20 black) attending a Detroit hospital-based HIV outpatient clinic were recruited for the study and underwent physical and mental health (HSCL-59 and NIMH DIS interview), behavioural and psychosocial evaluations, and a neuropsychologic screening test battery. The black and white men did not differ in terms of age, education, sexual behaviours, physical or mental health status. However, the black men were less likely to be open about their sexuality to their primary social support network, and to report that their social support was less affirmative than did the white men. When correlations between the six-dimensional social support measures (Wortman & O'Brien, 1987) and HSC-L distress scores were examined, both availability of material social support and affirmation were correlated negatively with distress among the white men but positively among the black men. Similarly, the previously observed positive relationship between perceived adequacy of social support and adoption of safer sexual practices was observed among white but not black participants.(ABSTRACT TRUNCATED AT 250 WORDS)

Flow cytometric measurement of cell cycle kinetics in rat Walker-256 carcinoma following in vivo and in vitro pulse labelling with bromodeoxyuridine

Flow cytometric measurements of total DNA content, cell cycle distribution, and bromodeoxyuridine (BrdUrd) uptake were made in rat Walker-256 carcinoma cells. After both in vivo and in vitro pulse labelling with BrdUrd, Walker-256 tumor cells were stained with propidium iodide (PI) to estimate the total DNA content and a monoclonal antibody against BrdUrd to estimate the relative amount of cells in S phase. BrdUrd-labelled single cell suspensions were harvested at different time intervals to determine the movement of these cells within the cell cycle. To increase BrdUrd uptake, fluorodeoxyuridine (FDU), a thymidine antagonist, was also applied in vivo and in vitro. The results indicated exponential growth characteristics for this tumor between days 5 and 8 after implantation. Tumor doubling times, derived from changes in tumor volume in vivo and from the increase in cell number in vitro were similar. The mean time for DNA synthesis was estimated from the relative movement of BrdUrd-labelled cells towards G2. The percent of cells labelled with BrdUrd and the DNA synthesis time were similar regardless of the mode of BrdUrd administration. This study demonstrates that BrdUrd labelling of rat Walker-256 carcinoma cells in vitro yields kinetic estimates of tumor proliferation during exponential growth similar to those with the administration of BrdUrd in the intact tumor-bearing rat.

Screening tests for intrauterine growth retardation: a comparison of umbilical artery Doppler to real-time ultrasound

In a study designed to compare Doppler umbilical artery velocimetry to ultrasound morphometric measurements in the prediction of intrauterine growth retardation, 636 paired ultrasound and Doppler umbilical artery examinations were performed between 24 and 40 weeks gestational age. Intrauterine growth retardation was defined as birth weight less than the tenth percentile per gestational age and 25 (9.2%) of the infants born in our study met this criteria. In general, when the gestational age was limited to less than 30 weeks, none of the tests were highly predictive of intrauterine growth retardation. Doppler umbilical artery systolic-to-diastolic ratios of greater than 3 had the highest sensitivity. However, due to inclusion of a large number of false-positives, it was considered a poor test. After 30 weeks, fetal abdominal circumference less than the tenth percentile had a greater sensitivity (45%) and positive predictive value (28%) than Doppler systolic-to-diastolic ratios greater than 3 (36% and 18%, respectively). Doppler ultrasound umbilical artery systolic-to-diastolic ratios are not more predictive of intrauterine growth retardation than ultrasound morphometric measurements.

A comparison between umbilical artery velocimetry and standard antepartum surveillance in hospitalized high-risk patients

One hundred forty-six women admitted to the high-risk obstetric unit between November 1987 and December 1988 participated in a study designed to compare Doppler umbilical artery flow studies with standard antepartum testing in the prediction of adverse fetal outcome. A Doppler ultrasound examination was considered abnormal when the average systolic/diastolic ratio was greater than or equal to 4. The antepartum testing consisted of a combined use of nonstress testing and contraction stress testing. If both the Doppler systolic/diastolic ratio and the antepartum testing were abnormal, there was a significantly increased incidence of intrauterine growth retardation (47%), fetal distress necessitating cesarean section (67%), and admission to neonatal intensive care (86%). Doppler umbilical artery flow studies are an important adjunct to antepartum fetal surveillance in high-risk patients but should not determine clinical management when standard antepartum surveillance remains normal.