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Biomedical subjects

P Black

Publications and source records attributed to P Black.

At least 19 recordsLinked to original sources
PubMed2000

Colon pouch (Mainz pouch III) for continent urinary diversion after pelvic irradiation.

OBJECTIVES: Urinary diversion after previous pelvic irradiation is challenging. The use of irradiated bowel in particular is associated with an increased rate of early and late complications. We therefore performed continent cutaneous urinary diversion using exclusively nonirradiated bowel segments in this group of patients. METHODS: A continent colon pouch for urinary diversion was performed in 44 female patients after pelvic irradiation. The indications were irreparable vesical fistula in 20, local recurrence of gynecologic tumors in 22, and radical cystectomy for bladder cancer in 2 patients. Depending on the length of the nonirradiated bowel segment, a transverse-ascending colon pouch (n = 8) or transverse-descending colon pouch (n = 36) was performed. The efferent segment was created from a tapered bowel segment embedded in the pouch wall. The ureters were implanted using a submucosal (n = 67) or subserosal (n = 17) extramural tunnel. RESULTS: No pouch-related complications were observed during the immediate postoperative period. In long-term follow-up (mean 52.2 months), upper urinary tract dilation was seen in five renal units. All five of these had been dilated preoperatively, and none required ureteral reimplantation. Incontinence occurred in 2 patients; both underwent reoperation with subsequent continence. Umbilical stoma stenosis was observed in 6 patients. CONCLUSIONS: The technique of the colon pouch for continent urinary diversion in previously irradiated patients is safe and has a low complication rate. The use of nonirradiated bowel segments should be the method of choice in this group of patients.

Adult↗
PubMed2000

Nephron-sparing surgery of renal cell carcinoma with a normal opposite kidney: long-term outcome in 180 patients.

OBJECTIVES: To investigate the long-term outcome of an organ-saving approach for renal cell carcinoma (RCC) with a normal opposite kidney (elective indication). METHODS: Since 1979, 180 patients have undergone nephron-sparing surgery at our institution for RCC in the presence of a normal contralateral kidney. The mean age was 56 years (range 23 to 83), and the mean follow-up was 4.7 years (maximum 14. 8). Most of these tumors were found incidentally, with a mean tumor diameter on ultrasound of 3.3 cm (range 1.0 to 8.6). RESULTS: The postoperative course was unremarkable in 173 patients. Postoperative bleeding was encountered in 4 patients and urinary extravasation in an additional 3 patients. No surgical reintervention was necessary. One hundred seventy-five RCCs were pT1 and 5 were pT3a; 73 were grade 1, 100 grade 2, and 7 were grade 3. The mean tumor diameter (surgical specimen) was 3.2 cm (range 0.5 to 7). In 132 cases, the tumor was less than 4 cm and in 48 cases, greater than 4 cm. Three patients experienced local tumor recurrence (1.6%) during follow-up, and two others developed distant metastases. The 5-year tumor-specific survival rate was 98.0%. CONCLUSIONS: Nephron-sparing surgery for RCC under an elective indication in selected patients offers excellent long-term survival and an acceptably low local tumor recurrence rate. These results support the concept of nephron-sparing surgery in the presence of a normal contralateral kidney.

Adult↗
PubMed2000

Vaginal reconstruction using the bladder and/or rectal walls in patients with radiation-induced fistulas.

OBJECTIVE: In irreparable or recurrent vesicovaginal fistulas and cloacal defects following high-dose irradiation therapy for gynecological malignancies, urinary diversion is the last resort to achieve a socially acceptable solution. In a select group of young and tumor-free patients, additional vaginal reconstruction may be indicated. Multiple operative procedures are available, but the results are often disappointing in the previously irradiated area. MATERIALS AND METHODS: In six such patients with large radiogenic vesicovaginal defects (n = 5) or a cloacal fistula (n = 1), a continent reservoir using the transverse colon with an umbilical stoma was performed. At the end of the operation, the bladder was incorporated into a neovagina by incising the urethra, anterior vaginal wall, and the posterior bladder wall with electrocautery from the urethral meatus to the dome of the fistula. RESULTS: No postoperative complications related to the vaginal reconstruction occurred. After a mean follow-up of 4.7 years, all patients had a capacious vagina and a wide introitus; the neovagina measured a mean of 18 cm in length. Five patients with a partner reported a normal sexual life. No dyspareunia or discomfort from bladder or urethral mucosa during intercourse was reported. CONCLUSIONS: Following continent urinary diversion due to irreparable vesicovaginal fistulas, a neovagina can be created by simple dissection of the posterior bladder and anterior vaginal wall. When a colostomy is present, the neovagina can additionally be augmented with a bowel flap of the Hartmann stump or by incising the rectovaginal septum. The technique affords good functional and cosmetic results.

Cloaca↗
PubMed2000

Surgical treatment of interstitial cystitis in women.

Interstitial cystitis is a clinical entity that has been known for a century, but its pathophysiology remains largely unknown and the optimal treatment is a matter of ongoing discussion. A successful strategy for treatment relies on precise appraisal of symptoms, clinical findings and histology, as well as on the patient's individual personality. The least invasive treatment possible should be chosen, and only after conservative options have been exhausted should a surgical solution be considered. In this respect, anatomical bladder capacity plays an important role. A large capacity indicates the potential for conservative treatment and may be regarded as a negative predictor for the outcome of orthotopic bladder substitution. In contrast, a small anatomical capacity is unlikely to respond to conservative therapy, but is associated with a high probability of successful orthotopic bladder substitution.

Cystitis, Interstitial↗
PubMed2000

The use of isolated caecal bowel segment in complicated vaginal reconstruction.

OBJECTIVE: To report a one-stage procedure, using a segment of caecum, both to overcome failed previous procedures and for primary vaginal replacement in patients with congenital vaginal aplasia, where primary reconstruction often results in vaginal obstruction and fistula formation. PATIENTS AND METHODS: The vagina was reconstructed using a 15-cm isolated caecal segment placed between the bladder and rectum and anastomosed to the introitus. Between 1985 and 1997 the technique was used in 17 patients (mean age 23 years). Indications included congenital malformations and vaginal loss through anterior exenteration or trauma. Seven of the 17 patients had undergone previous complex reconstructions; four of these had undergone previous fistula formation. Fourteen patients were followed for a mean of 3.6 (1-9) years. The surgical outcome was evaluated using a questionnaire completed by the patients. RESULTS: The postoperative course was unremarkable in all patients. Four patients developed an introital stenosis requiring surgical intervention. Two patients were minors at the time of follow-up, while all the others had had sexual intercourse and reported that they were very satisfied with the functional and cosmetic result. CONCLUSION: In patients in whom previous vaginal reconstruction has failed, the caecal segment should be used to create a neovagina. By considering the patient's age, the surgeon can optimize the surgical result.

Adolescent↗
PubMed2000

Regulation of secretion of PTHrP by Ca(2+)-sensing receptor in human astrocytes, astrocytomas, and meningiomas.

Parathyroid hormone-related protein (PTHrP) is the major mediator of the humoral hypercalcemia of malignancy and of malignant osteolysis associated with skeletal metastases of common epithelial cancers. PTHrP secretion is regulated by the extracellular calcium concentration ([Ca(2+)](o)) in several types of normal and malignant cells. Because the [Ca(2+)](o)-sensing receptor (CaR) is a key mediator of [Ca(2+)](o)-regulated hormone secretion [e.g., of parathyroid hormone (PTH) by parathyroid chief cells], we investigated the expression of the CaR and PTHrP in normal and neoplastic glial cells and studied the effects of [Ca(2+)](o) on PTHrP secretion. Our results show that primary embryonic human astrocytes (HPA) express CaR mRNA and protein as detected by RT-PCR and Western analysis, respectively. Furthermore, astrocytomas and meningiomas also express the CaR at similar levels as assessed by RT-PCR and Northern and Western blot analyses. HPA and astrocytomas express transcripts encoding all three known isoforms of PTHrP [PTHrP(139), PTHrP(141), and PTHrP(173), comprising 139, 141, and 173 predicted amino acid residues, respectively] as assessed by RT-PCR, whereas meningiomas express only the first two of these. Finally, elevated levels of [Ca(2+)](o) and other polycationic CaR agonists dose dependently stimulate PTHrP secretion from HPA, astrocytomas, and meningiomas, although both basal and high [Ca(2+)](o)-stimulated rates of PTHrP secretion are approximately 2. 5-fold higher in HPA than in the glial tumors studied here. Therefore, our results show that HPA, astrocytomas, and meningiomas express both the CaR and PTHrP and that CaR agonists stimulate PTHrP secretion.

Astrocytes↗
PubMed2000

Keyhole limpet haemocyanin in experimental bladder cancer: literature review and own results.

OBJECTIVES: Keyhole limpet haemocyanin (KLH) is a high-molecular-weight protein antigen collected from the haemolymph of the sea mollusk Megathura crenulata. It is a powerful non-specific immune response modifier that induces both a cell-mediated and a humoral response in animals and man. Thus, it is commonly used clinically as a measure of immune competence. In 1974, Olson studied the immune competence of bladder cancer patients by intradermal application of KLH. He later observed a significant reduction of recurrent disease in this patient group compared to another not immunized with KLH. This prompted a variety of experimental and clinical studies using KLH as an immunotherapy for recurrent bladder cancer. METHODS: Three different bladder cancer models have been used for experimental studies: intravesical transplantation of tumour cells in syngeneic mouse bladders; subcutaneous transplantation of tumour cells in syngeneic mice; direct chemical induction of bladder tumours by feeding rats with the carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine. RESULTS: The efficacy of KLH as an immunotherapeutic agent has been compared with different immune response modifiers alone or in combination with these in 11 experimental studies. Most of the studies used different concentration and application schedules for KLH. In addition a pre-immunisation prior to inoculation of the tumour was not performed in all studies. Therefore it is not useful to compare the results of these studies. However, most of the experiments demonstrated a significant effect on tumour appearance and extension after treatment with KLH. Intralesional or systemic application of KLH seemed to be superior to intravesical treatment. Pre-immunisation with KLH several days or weeks before tumour inoculation also seems to be a key point of success. No study reported severe side-effects after application of KLH; additionally performed toxicity studies underlined the good tolerability of KLH. CONCLUSION: Based on all the experimental studies, KLH has to be judged as an effective and safe immunotherapeutic drug for the treatment of experimental bladder cancer. Prospective randomised clinical trials should evaluate the role of KLH as an immunotherapeutic alternative in the prophylaxis of recurrent bladder cancer and should determine whether the efficacy of KLH in man may be improved by systemic application.

Adjuvants, Immunologic↗
PubMed2000

Urinary diversion and orthotopic bladder substitution in children and young adults with neurogenic bladder: a safe option for treatment?

PURPOSE: Combined pharmacotherapy, clean intermittent catheterization and infection prophylaxis is currently the gold standard of treatment for neurogenic bladder. However, as the adolescent gains independence from parental supervision, the intervals of clean intermittent catheterization compliance with medical treatment and regularity of followup examinations may decrease, and neurological and/or orthopedic status may change. This situation sometimes leads to failure of conservative treatment, resulting in incontinence and/or deterioration of the upper urinary tract. A multidisciplinary team was established at our institution 30 years ago to assess all aspects of care for patients with neurogenic bladder, of which urological function is just 1 aspect of the complex problem. Patient desires and essential medical goals, such as preservation of renal function, are considered by this team. An adequate compromise is sought and achieved in some cases by urinary diversion. We investigated the long-term safety of urinary diversion in these patients and its ability to protect the upper urinary tract. MATERIALS AND METHODS: Between 1967 and 1997 urinary diversion was performed in 149 patients with neurogenic bladder. Mean followup was 11.8 years (range 0.8 to 28.5) in 129 cases. Mean patient age at surgery was 12.1 years (range 0.8 to 20). A colonic conduit was created in 59 patients, mainly before the era of clean intermittent catheterization and continent diversion, while orthotopic bladder substitution was performed in 12 and continent urinary diversion (Mainz pouch I) in 58, of whom 50% were wheelchair bound. RESULTS: The upper urinary tract improved or remained stable in 97% of the renal units in patients with a colonic conduit or Mainz pouch I, and in 95% of the renal units in those with orthotopic bladder substitution. All patients with bladder substitution were continent during the day, 1 required occasional pads at night and 7 of 12 performed clean intermittent catheterization. Complete continence was achieved in 98% of those with a continent stoma. CONCLUSIONS: After failure of conservative treatment in patients with neurogenic bladder urinary diversion represents a safe long-term compromise. Daytime and nighttime continence is provided by the Mainz pouch bladder substitution and urinary diversion, while the upper urinary tract is protected by antireflux ureteral implantation.

Adolescent↗
PubMed2000

Nephron sparing surgery for central renal tumors: experience with 33 cases.

PURPOSE: Nephron sparing surgery is standard treatment for small, peripherally located renal cell carcinoma. In patients with a solitary kidney, bilateral tumors or impaired renal function nephron sparing surgery provides the only option to nephrectomy and subsequent hemodialysis or transplantation. We retrospectively investigated the value of nephron sparing surgery for centrally located renal cell carcinoma. MATERIALS AND METHODS: Between 1969 and 1997, 311 renal tumor enucleations were performed at our institution. The tumor was centrally located in 33 cases. The indication for enucleation was elective in 7 cases and imperative in 26, including bilateral tumor in 16 (metachronous in 9 and synchronous in 7), chronic renal failure in 4 and solitary kidney in 6. Four patients had metastasis at enucleation. RESULTS: Convalescence was unremarkable in 28 cases. Hemorrhage occurred in 1 patient, a urinary fistula in 2 and a local abscess secondary to a urinary fistula in 1. One patient died postoperatively of heart failure. Average serum creatinine was 1.25, 1.63 and 1.33 mg./dl. preoperatively, at hospital discharge and at a mean followup of 33 months, respectively. Hemodialysis was necessary transiently during convalescence in 1 patient and permanently starting 6 years after enucleation in another. Definitive histology revealed oncocytoma in 4 cases and renal cell carcinoma in 29. Disease was stages pT1 to pT3 in 9, 18 and 2 cases, and grades 1 to 3 in 6, 18 and 5, respectively. Local recurrence developed in 2 patients. Mean followup was 5.2 years (range 0.3 to 16.7). At a mean followup of 6.2 years (range 0.7 to 16.7) 20 patients were free of disease. In addition to the patient who died postoperatively, 9 died of renal cell carcinoma at a mean of 1.6 years (range 0.3 to 5.3) and 3 died of other causes at 5, 11 and 12 years postoperatively, respectively. No patient who underwent elective enucleation died. CONCLUSIONS: Nephron sparing surgery for centrally located kidney tumors is technically feasible and associated with an acceptable complication rate. Local tumor control is excellent, and the overall prognosis depends on contralateral disease and metastasis. Benign tumors may be diagnosed and removed without loss of the kidney. By avoiding hemodialysis quality of life is improved.

Adult↗
PubMed1999

Visual discrimination after anterior temporal lobectomy in humans.

OBJECTIVE: To determine whether right anterior temporal lobectomy (RTL) results in perceptual deficits, and whether the perception of particular stimulus features (i.e., shape, motion, color) is affected differentially. BACKGROUND: RTL results in abnormal visual discrimination, recognition, and recall of pictorial material that cannot be easily specified verbally, such as designs and faces. It is unclear whether stimuli must be conceptually meaningful to elicit perceptual deficits. METHODS: Tests were constructed to assess a wide spectrum of basic visual discrimination abilities with simple, meaningless stimuli. The performance of nine patients who underwent left temporal lobectomy (LTL) and nine patients who underwent RTL were compared with that of normal control individuals. The mean excision size along lateral cortex was 3.7 cm for the LTL group and 5.6 cm for the RTL group; mean mesial excision size was 5.2 cm for LTL and 4.6 cm for RTL. RESULTS: Basic visual discrimination capacities were demonstrated to be essentially intact after LTL and RTL, except for a mild loss of blue color discrimination after RTL. CONCLUSIONS: There is little evidence that RTL produces perceptual impairments limited to the domain of pattern perception, or generalizable to nonmeaningful stimuli. The perceptual loss after RTL may be largely restricted to extraction of meaning, and related to the disruption of the circuits that connect the outcome of visual analysis to previously stored semantic information.

Adult↗
PubMed1999

Comparison of immune reconstitution after unrelated and related T-cell-depleted bone marrow transplantation: effect of patient age and donor leukocyte infusions.

Unrelated bone marrow transplantation (BMT) is often complicated by fatal opportunistic infections. To evaluate features unique to immune reconstitution after unrelated BMT, the lymphoid phenotype, in vitro function, and life-threatening opportunistic infections after unrelated and related T-cell-depleted (TCD) BMT were analyzed longitudinally and compared. The effects of posttransplant donor leukocyte infusions to treat or prevent cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infections on immune reconstitution were also analyzed. This study demonstrates that adult recipients of TCD unrelated BMTs experience prolonged and profound deficiencies of CD3(+), CD4(+), and CD8(+) T-cell populations when compared with pediatric recipients of unrelated BMT and adults after related BMT (P <.01), that these adults have a significantly increased risk of life-threatening opportunistic infections, and that the rate of recovery of CD4 T cells correlates with the risk of developing these infections. Recovery of normal numbers of CD3(+), CD8(+), and CD4(+) T-cell populations is similar in children after related or unrelated BMT. This study also demonstrates that adoptive immunotherapy with small numbers of unirradiated donor leukocytes can be associated with rapid restoration of CD3(+), CD4(+), and CD8(+) T-cell numbers, antigen-specific T-cell responses, and resolution of CMV- and EBV-associated disease after unrelated TCD BMT.

Adolescent↗
PubMed1999

[Pilot study on early diagnosis of renal cell carcinoma by sonography].

UNLABELLED: The goal of this study was to investigate the practicability and effectiveness of a systematic screening for renal cell carcinoma by ultrasound in the course of the established German Health Ministry screening programs. METHODS: In two centers (Mainz and Wuppertal) a screening program for renal cell carcinoma for all citizens (age > 40 years) was established. The screening was divided into two phases (time period 1 year): (1) All citizens over 40 years could attend voluntarily a cost-free ultrasound investigation. (2) A follow-up investigation for the entire screening population was provided. RESULTS: Ten thousand volunteers attended the screening program. Mean age was 60 years. Thirteen renal cell carcinomas were detected. The incidence of other findings was 15%; none of those required further treatment. CONCLUSION: Systematic screening for renal cell carcinoma by ultrasound is cost-effective and showed high acceptance and practicability in a German population. The rate of detection of renal cell carcinoma was higher than initially statistically calculated.

Aged↗
PubMed1999

Reciprocal changes in endothelial and inducible nitric oxide synthase expression following carotid angioplasty in the pig.

OBJECTIVE: Nitric oxide produced by nitric oxide synthase appears to have an important role in the regulation of arterial tone, platelet adhesion and smooth muscle cell proliferation. Our aim was to investigate the effects of balloon angioplasty on expression of endothelial NO synthase (cNOS) and inducible NO/synthase (iNOS) in the pig carotid artery and to relate any changes in expression to the processes of reendothelialisation and vascular repair. METHODS: Pigs were sacrificed at various time points to follow NOS expression in the neointima, media and regenerated endothelium. Immunocytochemical staining was used to localize cNOS and iNOS expression in the vessel wall. Relative amounts of cNOS were measured using quantitative in vitro alitoradiography. cNOS mRNA and iNOS mRNA was quantified by competitive PCR based on the sequenced cDNA of porcine cNOS and iNOS. RESULTS: Uninjured carotid arteries exhibited dense uniform luminal endothelial staining for cNOS. Balloon angioplasty caused denudation of cNOS immunoreactive cells and a marked reduction of cNOS gene expression but a complete recovery was noted by day 35. In normal uninjured carotid arteries no evidence of iNOS immunoreactivity was demonstrable but 24 h after injury, marked homogeneous iNOS immunoreactivity was detected in medial vascular smooth muscle cells. By 5 days, staining was evident in cells within the forming neointimal layer with no evidence of iNOS immunoreactivity in the media. iNOS immunoreactivity persisted in cells at the luminal surface at 7 days and iNOS gene expression appeared to be sustained in some animals with ruptured internal elastic lamina at 21 days. CONCLUSION: Balloon injury is associated with de-endothelialisation and a marked reduction in cNOS gene expression and activity. iNOS is induced throughout the arterial media within VSMC soon after balloon injury and persists for up to 21 days. These observations imply an important regulatory role for locally generated NO in the pathophysiological response to balloon injury.

Amino Acid Sequence↗
PubMed1999

Obstetrical management following incontinence surgery.

OBJECTIVE: To analyze in a retrospective fashion our experiences with obstetrical management following previous incontinence surgery. METHODS: Between 1990 and 1997 4 women presented to our institution in the third trimester of pregnancy with a history of colposuspension performed 3 months to 4 years before onset of pregnancy for second degree stress incontinence. Three of 4 patients experienced recurrent incontinence during the third trimester. RESULTS: A cesarean section was performed before the onset of labor in all 4 patients. Postpartal pelvic floor exercises were prescribed and a follow-up ensued after 6 and 11 months in the form of a questionnaire. While incontinence persisted in 2 patients for 6 months, all 4 patients demonstrated complete continence after one year. CONCLUSIONS: We consider an elective cesarean section to be the optimal mode of delivery in women with a history of incontinence surgery.

Adult↗
PubMed1999

Strategies for reconstruction after unsuccessful or unsatisfactory primary treatment of patients with bladder exstrophy or incontinent epispadias.

PURPOSE: Following unsuccessful or unsatisfactory primary treatment in patients with the epispadias/exstrophy complex, the options for a surgical solution to preserve the upper urinary tract, to achieve complete continence, and to reconstruct the external and female internal genitalia are limited. We reviewed the records of the patients treated at our institution to determine a surgical compromise between ingenious operative constructions and patient desires, both of which are secondary to stabilization of renal function. MATERIALS AND METHODS: From 1967 to December 1997, 128 patients with bladder exstrophy/epispadias complex were treated, of 80 whom had received previous unsuccessful or unsatisfactory treatment. Of these patients 72 were followed for an average of 22.4 years after the first surgical intervention. There were 40 patients referred to our institution after primary bladder closure and bladder neck reconstruction, 10 after rectal bladder, 7 after ureterosigmoidostomy and 5 after incontinent diversion. RESULTS: At the latest followup 19 patients had a rectal reservoir, 38 an ileocecal pouch, 12 a conduit diversion and 3 an augmented Young-Dees procedure. The upper urinary tract remained stable in 95% of the renal units with rectal reservoir, 95% with ileocecal pouch, 96% with a colonic conduit and 100% with an augmented Young-Dees procedure. Day and night continence was achieved in 95% of the patients with a rectal reservoir and 97% of those with an ileocecal pouch were continent, whereas only 2 of the 3 patients with an augmented Young-Dees procedure were continent. Of the women 16 were satisfied with the cosmetic results and 6 delivered 8 children by cesarean section. Only 1 man was dissatisfied with the final cosmetic result. All adults but 1 engaged in sexual intercourse. CONCLUSIONS: The first operative intervention in patients with bladder exstrophy/epispadias complex determines their fate. After failure of primary treatment, the upper urinary tract must be stabilized. In patients with severely impaired renal function the colonic conduit is our method of choice while in those with a normal or slightly dilated upper urinary tract and intact anal sphincter we performed a rectal reservoir. In the remaining patients an ileocecal pouch guarantees continence day and night. The results of genital reconstruction are satisfactory.

Adult↗