Biomedical subjects

L Klotz

Publications and source records attributed to L Klotz.

At least 55 records · Page 3Linked to original sources

PubMed1994

Laparoscopic retroperitoneal lymphadenectomy for high-risk stage 1 nonseminomatous germ cell tumor: report of four cases.

OBJECTIVE: To evaluate in a prospective fashion the feasibility of performing retroperitoneal lymphadenectomy (RPL) for high-risk Stage 1 nonseminomatous germ cell tumors (NSGCT) using a laparoscopic technique, and to compare the results to historical controls. METHODS: RPL was performed laparoscopically on patients with Stage 1 NSGCT: Each patient had pathologic risk factors associated with an increased likelihood of metastases, and radiologic investigations revealed no evidence of retroperitoneal or distant disease. A modified template lymphadenectomy was performed in each case. The results of these four operations were compared to eight open RPLs performed on a similar group of patients. RESULTS: In 3 of the 4 cases, a thorough dissection was possible. In 1 of these 3, an open laparotomy was required to repair a caval laceration resulting from avulsion of a small lumbar vein at the end of the laparoscopic dissection. Compared to the open approach, there was considerably less postoperative morbidity. CONCLUSIONS: This procedure may represent an alternative approach to surveillance or open RPL for high-risk Stage 1 patients. Further experience is required to determine the sensitivity and effectiveness of this procedure compared to open RPL before its role in clinical practice can be established.

Adult↗

PubMed1993

Bilateral retrovesical testes: an unusual location for impalpable undescended testes.

Although the majority of impalpable undescended testes lie in an intracanalicular location, a significant number are also found to be intraabdominal. The expected location of intraabdominal testes is a line joining the renal hilum and the internal inguinal ring. We describe a case of an adult patient in whom impalpable undescended testes were located in a retrovesical location. This case highlights the importance of performing a thorough inspection of the entire abdomen and pelvis if the impalpable testis is not found in an expected location.

Adult↗

PubMed1992

Caries susceptibility and renal excretion of calcium.

Clearance studies were performed for 2 days in two groups of age-matched young female volunteers: those with low caries prevalence and those with high caries prevalence. Both groups were kept on a low-calcium diet for 1 week and received 0.5 g calcium at the beginning of the second day. In both groups, glomerular filtration rate, urinary flow rate and renal excretions of sodium, calcium, and phosphate were subject to significant circadian variations. In both groups the administration of calcium led to a significant increase in renal excretion of sodium and calcium and a significant decrease in that of phosphate. On the first day, calcium excretion was significantly greater in those with low caries prevalence than in those with high caries prevalence, pointing to altered calcium homeostasis in this group.

Adolescent↗

PubMed1991

Evaluation and treatment of blunt renal trauma.

We examined retrospectively the records of 126 patients with blunt renal trauma to determine the criteria for radiological investigations and the imaging study of choice. Of the 3,993 patients admitted to our regional trauma unit during the last 13 years 126 (3.1%) had blunt renal trauma. Mean patient age was 32 years (range 13 to 87 years) and the male-to-female ratio was 3:1. Mean followup was 7 months (median 4 months). Of the patients 72% had a minor renal injury, 17% had a moderate injury and 11% had a major renal injury. Treatment was conservative in 114 patients, while 9 underwent a genitourinary operation. Results were excellent in 87% of the patients and good in 8%, while 5% failed treatment. All patients who had microscopic hematuria without shock had minor injuries. Excretory urograms (IVPs) were normal in 74% and 39% of the patients when performed for minor and moderate renal injuries, respectively. Computerized tomography (CT) was abnormal in all cases when performed, and was more sensitive and specific than an IVP. Therefore, the majority of patients with blunt renal trauma can be treated conservatively with an excellent result. Furthermore, radiological investigations are not needed in those with microscopic hematuria and no shock. When radiological investigations are indicated a CT scan is the imaging study of choice.

Adolescent↗

PubMed1990

Basal epithelial cells of human prostate gland are not myoepithelial cells. A comparative immunohistochemical and ultrastructural study with the human salivary gland.

The hypothesis that basal epithelial cells of the human prostate are of myoepithelial origin was investigated using immunohistochemical and ultrastructural methodologies. The immunohistologic analyses show significant phenotypic differences between prostatic basal cells and myoepithelial cells of the salivary gland. Although both cell types stain intensely with the 312C8-1 monoclonal antibody, only true myoepithelial cells demonstrated significant amounts of muscle-specific actin as decorated by the HHF35 monoclonal antibody. Furthermore, using double-labeling experiments, the prostatic basal cells were strongly decorated with a fluorescein-tagged basal cell-specific keratin but were negative with the rhodamine-tagged phalloidin, a chemical that binds specifically to actin microfilaments. Ultrastructural studies also showed an absence of thin microfilament bundles, dense bodies, and micropinocytotic vesicles in the prostatic basal cells. The current investigations show that the prostatic acini do not have a basal myoepithelium. Although some authors have suggested a stem cell role for prostatic basal cells, the weight of experimental work argues against this hypothesis. The exact role of the basal epithelial cells of the prostate is not known, although they may serve endocrine, paracrine, or other regulatory functions and may be involved in modulating signals between prostatic stroma and epithelium.

Actins↗

PubMed1988

Effect of acetylcholine on electrical properties of subconfluent Madin Darby canine kidney cells.

To elucidate the effects of acetylcholine on the electrical properties of incompletely confluent Madin Darby canine kidney (MDCK) cells continuous measurements of the potential difference across the cell membrane (PD) were made with conventional microelectrodes during rapid changes of extracellular fluid composition. During control conditions PD averages -48.9 +/- 1.0 mV (n = 51). 1 mumol/l acetylcholine leads to a sustained but reversible hyperpolarization of the cell membrane by -17.9 +/- 0.7 mV (n = 51). Half-maximal effect is observed at some 100 nmol/l. 1 mumol/l atropine does not significantly alter the potential difference across the cell membrane, but abolishes reversibly the hyperpolarizing effect of acetylcholine. Increase of extracellular potassium concentration from 5.4 mmol/l to 20 mmol/l depolarizes the cell membrane by +12.1 +/- 1.1 mV (n = 12) in the absence and by +25.7 +/- 0.9 mV (n = 12) in the presence of acetylcholine. Within 80 s removal of extracellular calcium leads to a depolarization of the cell membrane by +16.2 +/- 3.2 mV (n = 9). In the nominal absence of extracellular calcium acetylcholine leads to a transient hyperpolarization by -13.8 +/- 1.8 mV (n = 9), which can be elicited only once. In conclusion, acetylcholine hyperpolarizes the plasma membrane of MDCK cells by calcium-dependent enhancement of potassium conductance.

Acetylcholine↗

PubMed1987

Fertility status of patients with clinical stage I testis tumors on a surveillance protocol.

A potential benefit of a surveillance protocol for the management of patients with clinical stage I testis tumors is the avoidance of ejaculatory disturbances and infertility resulting from retroperitoneal lymph node dissection, the standard treatment for patients with this stage of disease. To address this issue we evaluated 22 patients with clinical stage I testis tumors on a surveillance protocol with history, physical examination and semen analysis. Previous fertility was unknown or it had not been tested in the majority of the patients (74 per cent). Ten patients (45 per cent) had abnormal spermatogenesis on the basis of a low sperm count or sperm motility. Of 6 patients with oligospermia or azoospermia 3 had recovered normal spermatogenesis when they were re-evaluated 4 to 19 months later. Although in this group of carefully staged cases the incidence of subfertile sperm counts seems to be similar to those with higher stage disease, some patients with abnormal counts clearly recover. The avoidance of retroperitoneal lymph node dissection seems to spare fertility in at least a small percentage of these patients.

Adult↗

PubMed1985