Lamina propria of sex cords in human fetal testis: an immunohistological and stereological study

Testicular peritubular cells are located in the lamina propria of seminiferous tubules. These cells, significantly contributing to the basal membrane of seminiferous epithelium, have been studied in a number of species. However, there is a lack of data on the development of the lamina propria in the human testis. The aim of our survey was to investigate the characteristics of the lamina propria and, in particular, peritubular cells in the fetal human testes by immunohistological and stereological methods. Therefore, testes (14–39 weeks of gestation, n=45) were dissected and fixed in a 4% buffered paraformaldehyde solution. Several pieces of each testis were embedded in paraffin and processed for immunohistochemical and stereological analysis. All investigated testes have shown sex cords in the process of development and differentiation. Morphologically, peritubular cells in the lamina propria can be divided into two types: fibroblast-like (FL) and myoid-like (ML) type (cells which much resemble mature myoid cells). By immunohistochemistry, both FL and ML cells are found to be strongly positive for the intermediate filament desmin, but negative for -smooth actin. While FL cells intensively express Ki-67 demonstrating proliferative activity, ML cells are found to be negative. The basement membrane of sex cords as well as the blood vessels of the interstitium show strong positivity to collagen IV and laminin. Concerning the correlation between the appearance of the investigated antigens with the gestational age, all antigens have been expressed (in the manner described above) already in the 14th week of gestation. The stereological analysis of the number (Nv) and volume (Vv) of peritubular cells indicates a pulsatile development of these cells in the lamina propria of the human fetal testis. While the stereological variables determined for FL cells show a gradual decrease, the same variables determined for ML cells demonstrate a successive increase. It appears that the lamina propria of the fetal human testes shares many of the properties previously discovered in rodents.     

Rate of alcohol metabolism; do not "correct" the beta 60 estimate for comparisons among ethnic groups

Many studies have attempted to "correct" or "refine" initial beta 60 estimates of the rate of alcohol metabolism. The present study, however, finds that such "corrections" may be in error and that beta 60 is the best estimate now available for comparisons of alcohol clearance among individuals or ethnic groups.     

Educating allied health professionals to provide care for cancer patients and their families

From 1985 to 1988, a state-wide program of cancer education was offered to community-based allied health professionals (AHPs) at five different program sites in Pennsylvania. During this three-year period, 512 social workers, clergy, dieticians, physical therapists and others received training to increase their knowledge about cancer and counseling, improve their supportive attitude regarding cancer patients and families, and decrease stress related to their work with this population. Overall, the Program was successful in reaching AHPs working with cancer clients who had little formal training in the cancer field. At the beginning of training, it was observed that AHPs with initially higher levels of education and more years of work experience with cancer patients had higher levels of counseling knowledge. Those who were women, worked in hospitals, or had worked with cancer patients longer exhibited higher levels of cancer knowledge. Participants who were women and who had more education had reported lower levels of job stress. Among those AHPs who completed the training courses, cancer knowledge increased by 14 percent. In addition, knowledge related to counseling cancer patients and their families improved by 11 percentage points. Perceived job stress among the AHPs also declined by 10 percent. Finally, participant supportive attitude concerning cancer clients improved.     

Adrenoceptor-mediated effects on calcium channel currents are antagonized by 5′-(N-ethyl)-carboxamido-adenosine in guinea-pig atrial cells

Summary In guinea-pig atrial myocytes, the effects of the adenosine analogue 5-(N-ethyl)-carboxamido-adenosine (NECA) in the presence of isoprenaline (ISO) on Ca²⁺ channel activity were analyzed. Single Ca²⁺ channel currents were recorded from cell-attached patches by application of several hundred 100 ms depolarizing steps. Under control conditions, burstlike activity of channel openings during some depolarizing steps were followed by variably long periods of quiescence (blank sweeps). During superfusion with ISO (100 nmol/l), ensemble-averaged (mean) current was increased by about 150%. The underlying mechanism was found to be a significant increase in the channel availability, defined as the ratio of current-containing sweeps to the total number of sweeps. In addition, the ISO-induced reduction of blank sweeps was combined with slightly but not significantly higher values of the open probability in the current-containing sweeps. Open time and shut time histograms could be fitted by single and double exponential curves, respectively, which remained rather unaffected in the presence of ISO; accordingly, mean open time and mean shut time of the channel were not significantly changed by ISO. After the addition of NECA (1 mol/l) in the presence of ISO, the ISO-induced increase in mean current was abolished. This effect of NECA on mean current was due to a reduction of the channel availability and a slight decrease in the open probability. The purinoceptor blocking agent 8-phenyltheophylline (10 mol/l) antagonized the inhibitory action of NECA on the ISO-induced increase in Ca²⁺ channel activity. These results indicate that -adrenoceptor-induced changes in Ca²⁺ channel activity are counteracted by stimulation of, presumably, A₁ adenosine receptors. This may be explained by the fact that purinoceptors, beside their stimulating action on K⁺ channels, mediate an additional inhibitory effect on the adenylate cyclase system in the atrium. Subsequently, purinoceptor activation reverses the ISO-induced increase in Ca²⁺ channel activity due to a reduction in cAMP content leading to a decrease in the number of phosphorylated Ca²⁺ channels. Send offprint requests to U. Jahnel at the above address     

Urine test strips: reliability of semi-quantitative findings under tropical conditions

Semi-quantitative urinalysis with urine reagent strips (URS) for erythrocyturia (EU), leucocyturia (LU) and proteinuria (PU) was performed in Congolese and Sudanese school children withSchistosoma haematobium and/orS.mansoni infection. Quantitative urinalysis was performed on the same specimen using microscopy and a Neubauer counting chamber for EU and LU and the Coomassie blue dye-binding assay for PU. Microscopically detectable EU of more than 10 cells/l was found in 63% of all samples and LU of more than 20 cells/l was found in 60% of all samples. With the Coomassie blue method, PU of more than 150 mg/l was detected in 51% of all samples. URS gave positive results of grade 1–3 for EU in 69% of all samples, for LU in 63% of all samples and for PU in 66% of all samples. The sensitivity and specificity of URS compared with standard reference methods were as follows: EU 95% and 75%, LU 81% and 81% and PU 90% and 56%. When the results of all three test were combined, URS differentiated abnormal from normal urine specimens with a sensitivity of 94% and a specificity of 70%. Median quantitative results showed a good correlation with semiquantitative URS readings for all parameters, but there was a wide range of URS scores.We concluded that URS sensitively detect urinary abnormalities and thus may be used as a general screening method under field conditions when more specific methods cannot be performed. In the hospital laboratory,urine microscopy with a counting chamber would be preferred to URS as a sole method for EU and LU detection; URS is useful for the detection of PU in the tropical hospital laboratory where an appropriate quantitative method with a better specificity may not be available.     

Klinische und feinmotorische Therapiekontrolle bei Morbus Wilson

At the time of diagnosis and after therapy, we examined 33 patients suffering from Wilson's disease. We applied a standardized diagnostic score system on the basis of clinical signs. Without observing any differences between pseudoparkinsonian and pseudosclerosis subtypes, patients with neurological symptoms significantly improved by 2.33 points. Patients with initially more severe symptoms showed the same improvement as less affected patients. Fine motor disturbances were evaluated using the V-scope system. Finger tapping and drawing a spiral were compared to values of a healthy control group (n = 52). Patients with neurological symptoms showed significantly decreased frequencies in both tests. The clinical score was related to frequencies in finger tapping but not in drawing a spiral. Therefore finger tapping can be used as an objective diagnostic tool to evaluate the severity of Wilson's disease, while spiral testing appears to be a sensitive screening tool.     

Preoperative Evaluation of Pancreatic Masses with Positron Emission Tomography Using 18F-fluorodeoxyglucose: Diagnostic Limitations

Identification of pancreatic cancer in patients presenting with an enlarged pancreatic mass is a major diagnostic problem. Positron emission tomography (PET) using the radiolabeled glucose analogue ¹⁸F-fluorodeoxyglucose (FDG) has been suggested to provide excellent accuracy for noninvasive determination of suspicious pancreatic masses. We conducted a prospective study to verify these results. Forty-two patients admitted for pancreatic surgery underwent PET scanning. Image analysis was based on visual film evaluation and quantification of regional tracer uptake. PET imaging was visually analyzed by three observers blinded for the results of other diagnostic tests; they qualitatively graded the scans using a five-point scale (I = low to V = high) for the presence and intensity of focal FDG uptake. Diagnosis was proven by histology (n= 38) or follow-up (n= 4). Furthermore, the results of PET were compared with helical computed tomography (CT) and conventional ultrasonography (US), done during the routine diagnostic workup before pancreatic cancer surgery. Regarding only the results with scores of IV and V as positive for representing definite malignancy yielded a sensitivity of 71% and a specificity of 64% for film reading. Quantification of regional tracer uptake contributed no significant diagnostic advantage for differentiation between benign and malignant tumors. Helical CT revealed a sensitivity of 74% and a specificity of 45.5% and abdominal US 56% and 50%, respectively. We concluded that PET imaging provides only fair diagnostic accuracy (69%) for characterizing enlarged pancreatic masses. PET does not allow exclusion of malignant tumors. In doubtful cases, the method must be combined with other imaging modalities, such as helical CT. The results indicate that the number of invasive procedures is not significantly reduced by PET imaging.     

Use of replicating oncolytic adenoviruses in combination therapy for cancer.

Oncolytic virotherapy is the use of genetically engineered viruses that specifically target and destroy tumor cells via their cytolytic replication cycle. Viral-mediated tumor destruction is propagated through infection of nearby tumor cells by the newly released progeny. Each cycle should amplify the number of oncolytic viruses available for infection. Our understanding of the life cycles of cytolytic viruses has allowed manipulation of their genome to selectively kill tumor cells over normal tissue. Because the mechanism of tumor destruction is different, oncolytic virotherapy should work synergistically with current modes of treatment such as chemotherapy and radiation therapy. This article focuses on oncolytic adenoviruses that have been created and tested in preclinical and clinical trials in combination with chemotherapy, radiation therapy, and gene therapy.     

Vascular compression of the airway: Indications for and results of surgical management

Vascular compression of the airway is a significant cause of respiratory compromise in children. While the indications for surgical repair are sometimes life threatening, they can also be subtle. This retrospective study examines 45 surgical cases of tracheobronchial compromise secondary to vascular compression at a large children's hospital between July 1983 and February 1996. A total of 34 were diagnosed with innominate artery compression, ten with a double aortic arch and one with an anomalous right subclavian artery. The 45 patients, 25 male and 20 female, ranged in age from 12 days to 11 years at surgery (average 13 months). A total of 21 (47%) presented with proven or suspected episodes of cyanosis or apnea. All 45 patients had evidence of vascular compression during microlaryngoscopy and bronchoscopy. The diagnosis was confirmed by magnetic resonance imaging (MRI) in 23/45 (51%), barium swallow in 22/45 (49%) and aortogram in 3/45 (7%). There was one death. One patient had a tracheotomy before surgery and continues to require it after surgery. Complete resolution of symptoms was achieved in 39/45 (87%) with five requiring more than one operation before their symptoms resolved completely. A total of four patients experienced a recurrence of symptoms within a variable length of time after surgery. Surgical indications and treatment alternatives will be discussed.