Behavioral instrumental reactions and the frequency of cardiac contractions in chimpanzees with different rates of approaching a goal and a shortened time of its exposure

Reaching the goals moving with different speed (from 1 to 400 mm/sec), the chimpanzee revealed respective behavioural, emotional, instrumental, and cardiovascular responses. When obscuring the goal for a certain time, the chimpanzee nevertheless managed to reach it, the relations between the speed of approaching goal and behavioural or instrumental responses being preserved. Thereupon, the chimpanzee are able to reach the goal provided the latter's trace exceeds 5-10-fold the time of really acting stimulus.     

The delta 5-3 beta-hydroxy steroid acyl transferase activities in tissues of the male rat and sheep

The present study reports on the results of a follow-up examination of patient material, 5 years after the installation of the fixed supraconstruction. The patient group comprised 11 individuals. Briefly, a split-mouth technique of treatment was used. In the right side of the mandible the traditional 2-step surgical approach for implant installation was used. In the left jaw quadrant a 1-step surgical procedure was used. A clinical and radiographical examination was performed 5 years after the initial connection of the supraconstruction to the implants. At the 5-year follow-up examination all 61 implants examined at the 18-month follow-up were still in service and found to be clinically stable irrespective of the surgical procedure used. Furthermore, the results of the present clinical and radiographical follow-up study demonstrate that the marginal bone level at implants placed anteriorly in the edentulous mandible and supporting fixed supraconstructions is stable between 18 and 60 months irrespective of whether placed according to a 1-step or 2-step surgical procedure.     

The six N-linked carbohydrates of the lutropin/choriogonadotropin receptor are not absolutely required for correct folding, cell surface expression, hormone binding, or signal transduction

Using two separate methods, we have determined that all six potential sites for N-linked glycosylation on the rat lutropin/choriogonadotropin receptor (rLHR) contain carbohydrates. The functional roles of the carbohydrates were analyzed initially through the use of two nonglycosylated receptor mutants rLHR(N(77,152,173,269,277,291)Q) and rLHR(N(77,152,269,277,291)Q;T(175)A). Although Western blot analyses demonstrated both mutant receptors to be stably expressed, little or no hCG binding activity could be detected in detergent solubilized extracts of 293 cells expressing either nonglycosylated LHR mutant. Although this loss of hCG binding was concluded to be due to misfolding, it was unknown whether this misfolding was due to the absence of carbohydrates or to the multiple amino acid substitutions that had been introduced into the polypeptide. To differentiate between these possibilities, hCG binding assays were performed with nonglycosylated receptors obtained after tunicamycin treatment of cells expressing the wild-type rLHR. Even though these wild-type receptors were confirmed to be devoid of all N-linked carbohydrates by Western blots, they were found to bind hCG with a normal high affinity. In addition, tunicamycin-derived, nonglycosylated LHRs were present at the cell surface and exhibited a phenotype consistent with mature receptors due to their capability to mediate hCG-stimulated cAMP production as well as bind oLH with high affinity. These results indicate that the loss of high affinity hormone binding by rLHR(N(77,152,173,269,277,291)Q) and rLHR(N(77,152,269,277,291)Q;T(175)A) is simply due to the collective amino acid substitutions rather than to the absence of carbohydrates. Therefore, N-linked carbohydrates are not absolutely required for the proper folding of the rLHR into a mature receptor capable of binding hormone and signaling. These results are in marked contrast to the follitropin receptor (FSHR), a very similar receptor which has been shown to strictly require N-linked carbohydrates for folding of the nascent protein.     

Massive hemorrhage caused by a perforating Gianturco-Z stent resulting in an aortoesophageal fistula

Squamous cell carcinoma of the tonsil has a relatively poor prognosis. Aggressive surgery, radiation therapy and combinations of irradiation and surgery have been employed but there exists some controversy about the efficacy of these treatment modalities. The purpose of this paper is to compare the efficacy of treatment between the surgery followed by radiation therapy and the preoperative radiation therapy followed by surgical resection. The medical records of 33 patients treated for squamous cell carcinoma of the tonsil at the Department of Otolaryngology-Head and Neck Surgery, Korea University Hospital between 1989-1993 were reviewed retrospectively. None of the patients were stage I, but stage II, III, and IV were four, five, and 24 patients, respectively. There were 30 males and three females. The most common histopathology was moderately differentiated squamous cell carcinoma (20/33). The 13 patients treated initially with surgery had an overall three-year survival rate of 38.5%, and the rate for the 20 patients treated initially with radiation was 40%. The main pattern of treatment failure was a local recurrence and neck metastases, and pathologic differentiation thought to be an important prognostic factor. Complications are fewer in patients treated initially with surgery (23.1%) than patients initially treated with radiation (50.0%). There is no difference in the efficacy between the two therapeutic groups.     

Electron tomography of large, multicomponent biological structures

Genome-wide scans for linkage of chromosome regions to type 1 diabetes in affected sib pair families have revealed that the major susceptibility locus resides within the major histocompatibility complex (MHC) on chromosome 6p21 (lambda s = 2.5). It is recognised that the MHC contains multiple susceptibility loci (referred to collectively as IDDM1), including the class II antigen receptor genes, which control the major pathological feature of the disease: T lymphocyte-mediated autoimmune destruction of the insulin-producing pancreatic beta cells. However, the MHC genes, and a second locus, the insulin gene minisatellite on chromosome 11p15 (IDDM2; lambda s = 1.25), cannot account for all of the observed clustering of disease in families (lambda s = 15), and the scans suggested the presence of other susceptibility loci scattered throughout the genome. There are four additional loci for which there is currently sufficient evidence from linkage and association studies to justify fine mapping experiments: IDDM4 (FGF3/11q13), IDDM5 (ESR/6q22), IDDM8 (D6S281/6q27) and IDDM12 (CTLA-4/2q33), IDDM4, 5 and 8 were detected by genome scanning, and IDDM12 by a candidate gene strategy. The results suggest that the clustering of type 1 diabetes in families is due to the sharing of alleles at multiple loci, and that the as yet unidentified environmental factors are not causing clustering, but instead appear to influence the overall penetrance of genetically programmed susceptibility. The data are consistent with a polygenic threshold model for the inheritance of type 1 diabetes.     

PCR-restriction fragment length polymorphism (RFLP) analyses reveal both extensive clonality and local genetic differences in Candida albicans

Using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to obtain genotypes for the diploid pathogenic yeast, Candida albicans, we analysed 204 C. albicans isolates from three populations of the Duke University community: two from clinical sources [one from patients infected with human immunodeficiency virus (HIV) and the other from patients without HIV infection], and the third from healthy student volunteers. The results indicated: (i) extensive evidence for clonality within and between populations of C. albicans; and (ii) greater genotypic and gene diversities in the nonclinical population than those derived from clinical specimens, regardless of HIV status. The two clinical populations were genetically more similar to each other than either was to the population consisting of isolates from healthy people. Within each population sample there was a general lack of heterozygotes, and random associations of alleles within and between loci were found in less than 50% of the loci or pairs of loci. These findings were consistent between the two sets of samples analysed: those including all isolates and those including only clone-corrected isolates. Possible mechanisms are presented to explain the observed patterns of genetic variation within and between C. albicans populations.     

A case of fatal pulmonary thromboembolism associated with the use of intravenous estrogen therapy

OBJECTIVE: To report a case of fatal pulmonary embolism associated with the use of i.v. estrogen therapy for menometrorrhagia. DESIGN: Case report. SETTING: University hospital. PATIENT(S): A 52-year-old woman with fibroid uterus treated with GnRH analogues with add-back therapy who presented with excessive vaginal bleeding. INTERVENTION(S): Intravenous conjugated estrogens were administered for a total of six doses. MAIN OUTCOME MEASURE(S): Fatal thromboembolic event. RESULT(S): The day after i.v. conjugated estrogens were administered, the patient had only scant vaginal bleeding, but she experienced the sudden onset of respiratory distress, became comatose, and subsequently had ventricular fibrillation leading to asystole. All resuscitative efforts failed. Postmortem examination revealed bilateral pulmonary artery thromboembolism (saddle embolus). CONCLUSION(S): Intravenous conjugated estrogen therapy may be complicated by fatal thromboembolic events. This potential adverse effect must be considered in the use of such therapy for severe menometrorrhagia, especially when treating a patient at increased risk.     

Sonographic findings in testicular sarcoidosis simulating malignant nodule

Testicular involvement by sarcoidosis is rare. We report a case of a patient with known sarcoid who had a unilateral testicular nodule with apparent capsular invasion on sonography. The epididymis was normal on both sides. Despite these atypical features, pathology showed the nodule to be a sarcoid granuloma. In patients with sarcoidosis, the differential diagnosis of an intratesticular mass should include testicular involvement by sarcoid.     

Isoenzyme analysis of Arthrobotrys, a nematode-trapping fungus

Extraction and isoenzyme analysis of four isolates of Arthrobotrys including A. musiformis, A. robusta and A. conoides were conducted. Among the 14 enzymes studied by starch gel electrophoresis, using morpholine-citrate as gel/electrode buffer, the following nine enzymes showed interpretable banding patterns: alpha-esterase, fumarase, hexokinase, isocitrate dehydrogenase, leucine aminopeptidase, malate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase and phosphoglucoisomerase. All isolates studied displayed typical isoenzyme phenotypes for each species. Two isolates of A. conoides differed in their alpha-isoesterase banding patterns, but no differences were observed for the other enzymes. The assay was satisfactory for enzyme extraction and resolution of Arthrobotrys and could be used in future taxonomic and genetic studies of this organism.