Characteristics of burst noise intermittency

An investigation of burst noise intermittency in both NPN and PNP planar transistors has shown that definite statistics exist for the phenomenon. It has also been found that in some cases the superposition theorem is invalid when dealing with devices which have several burst noise sources.     

Attentional processing of "unattended" flankers: evidence for a failure of selective attention

The objective of this study was to investigate the interaction between sulfogalactosylceramide (SGC) and dimyristoylphosphatidylcholine (DMPC) in a mixed model liposomal system (molar ratio SGC:DMPC, 2:3). Structural and dynamic changes of the liposome components were monitored by Fourier-transform infrared spectroscopy (FTIR). Thermotropic FTIR analysis of the mixed liposomes showed a single gel/liquid crystalline phase transition, centered at approximately 42 degrees C. Spectral changes of the amide and ester C = O bands arising from functional groups at the interfacial region indicated a reduced hydrogen bonding of these groups in the mixed liposomes. Pressure-tuning FTIR of mixed liposomes showed that the methylene chains of SGC and DMPC were more orientationally disordered than those of the individual lipid SGC liposomes or DMPC liposomes. These results suggest that the mixed liposomes (molar ratio SGC:DMPC, 2:3) consisted of a homogeneous mixture of SGC and DMPC molecules in which mutual shielding reduced hydrogen bonding in the interfacial region, with a concurrent increase in the orientational disorder of the hydrocarbon chains of both SGC and DMPC.     

RCS reduction of dihedral corners

Corner reflectors are inadvertently formed by many surfaces on ships and military ground vehicles and can be dominant contributors to the radar cross section (RCS). The monostatic return from such structures can be reduced by ensuring that flat surfaces never meet at right angles. A criterion is developed that gives the required angle as a function of the RCS reduction desired and the electrical size of the corner faces.     

PET studies on brain monoamine transporters with carbon-11-beta-CIT in Parkinson's disease

The cocaine analog 2 beta-carbomethoxy-3 beta-[4-iodophenyl]tropane (beta-CIT) labeled with 11C was used to study dopamine reuptake sites with PET. METHODS: Three normal subjects and nine patients with Parkinson's disease were investigated. Each of them underwent a dynamic PET scan (25 timeframes over 80 min) with [11C]-beta-CIT. A dose of 102.5-211.3 MBq (2.77-5.71 mCi) of this ligand was administered intravenously and a PET examination with an ECAT 931/08 PET camera was carried out. Ratios between the striatal/cortical/thalamic/midbrain and cerebellar uptake of this radioligand were calculated. RESULTS: The highest accumulation of [11C]beta-CIT was observed in the caudate and putamen, though there was some uptake in the thalamus and the midbrain. Cortical uptake was negligible. Carbon-11-beta-CIT accumulated significantly less in the putamen of the Parkinson's patients than in the normal subjects. The putamen-to-cerebellum ratio in the Parkinson's patients was 1.59 +/- 0.04 and 1.80 +/- 0.13s (p = 0.028) in the normal subjects. In the caudate, there was no significant difference between the Parkinson's patients and the normal subjects. CONCLUSION: These results imply that [11C]beta-CIT is a useful compound for carrying out a PET examination of the function of the presynaptic monoaminergic neurons both in normal and pathological brains.     

Variation in the hepatotoxic effects of carbon disulphide between different strains of rat

The hepatotoxic effects of carbon disulphide have been investigated in an outbred (Porton) strain of rat and in 8 inbred strains. Carbon disulphide (1.38 mmoles/kg body weight) was administered intraperitoneally to rats which had been pretreated with phenobarbitone and starved. Livers were taken for analysis 24 h later. A considerable genetic variation in the response of rats to carbon disulphide was observed. The extent of centrilobular hydropic degeneration varied greatly between strains and was accompanied by a high incidence of focal coagulative necrosis in the most susceptible rats. Analysis of variance of the accompanying changes in liver weight and water content and in total liver cytochrome P450 content gave statistical confirmation of a strain effect in the response to carbon disulphide. Highly significant strain x treatment interactions for these parameters were attributable to changes after carbon disulphide treatment rather than variation between phenobarbitone pretreated starved controls. The experiments were repeated in two blocks, 3 months apart. Block effects and interactions were significant in some cases but were quantitatively small and did not obscure a ranking based on histological assessment. AGUS rats were least affected by carbon disulphide whereas PVG and LEW rats showed extensive liver damage. Other strains (WA, Porton, F344, BDIX, WAG) showed a gradation of response between these extremes.     

Actions of carbocromen of toxic effects of digitalis (author's transl)

Experiments an anaesthetized dogs, rabbits and guinea pigs show that with clinically relevant doses of 3-(2-diethyl-aminoethyl)-4-methyl-7-(carbethoxy-methoxy)-2-oxo-1,2-chromene-hydrochloride (carbocromen, Intensain?) the LD100 of digoxin (+50%) and ouabain (+60%) considerably increase. The positive inotropic effect of digoxin is not influenced by carbocromen. The appearance of arrhythmias is significantly delayed, the coupling between atrial and ventricular activity continues for a longer time. Besides effects on myocardial metabolism a membrane effect of carbocromen could be responsible for the improvement of the therapeutic range of digoxin and ouabain.     

Basal cell carcinoma of the genitalia

BACKGROUND: Basal cell carcinomas (BCC) arising on the genitalia are exceedingly rare with an unclear pathogenesis. OBJECTIVE: To better understand risk factors, tumor characteristics, and the possible role of human papillomavirus (HPV) in the development of BCC of the genitalia. METHODS: 1543 records of Mohs micrographic surgery performed during a 6-year period were reviewed to identify cases of BCC arising on the genitalia. Tumor tissue was analyzed for HPV DNA by in situ hybridization. RESULTS: Four patients with BCC of the genitalia were treated with Mohs micrographic surgery. The malignancies were located on the scrotum, perineum, and perianal areas in the three male patients and on the vulva in the female patient. The mean age was 67 years. None of the patients had prior history of skin cancers. Histologic evaluation of the tumors revealed two nodular subtypes, one superficial subtype, and one with follicular differentiation. In situ hybridization failed to reveal DNA of HPV types 6, 11, 16, 18, 30, 31, 33, 35, 45, 51, and 52. CONCLUSION: In this small series, genital BCC occurred in an older age group with no identifiable predisposing risk factors and did not show evidence of HPV infection.     

Prevalence of nephrotoxicosis associated with a four-hour saline solution diuresis protocol for the administration of cisplatin to dogs with naturally developing neoplasms

We evaluated the development of nephrotoxicosis in 64 dogs with malignant neoplasia given cisplatin during 4-hour saline solution diuresis. Cisplatin (70 mg/m2 of body surface area, IV, q 21 d) was given to 8 dogs once, 22 dogs twice, 9 dogs 3 times, and 25 dogs 4 times. For each treatment, cisplatin was given over a 20-minute period after saline (0.9% NaCl) solution was administered IV for 3 hours at a rate of 25 ml/kg/h. After cisplatin infusion, saline solution diuresis was continued at the same rate for 1 hour. Before each treatment with cisplatin, the dogs were evaluated by conducting a physical examination, CBC; and analysis of serum urea nitrogen and creatinine concentrations, and in most cases, serum phosphorus concentration and urine specific gravity were determined. Exogenous creatinine clearance also was evaluated in 8 dogs prior to 1 (n = 8), 2 (n = 8), 3 (n = 6), and 4 (n = 4) treatments. Five (7.8%) of 64 dogs developed clinically evident renal disease after two (n = 3) and three (n = 2) doses of cisplatin. Two of the 5 dogs had preexisting diseases of the urinary tract prior to the start of treatment. Survival time in dogs that developed renal disease (median, 114 days; range, 26 to 273 days) was similar to that of all dogs in this study (median, 145 days; range, 5 to 586 days), with 30 dogs still alive at the conclusion of the study. Three of the 5 dogs that developed renal disease were alive at the conclusion of the study, 1 died of tumor-related causes, and another died as a direct result of nephrotoxicosis. There was a significant (P < 0.05) decrease in median neutrophil counts and a significant (P < 0.05) increase in median creatinine concentrations prior to the third and fourth treatments, compared with pretreatment values.(ABSTRACT TRUNCATED AT 250 WORDS)     

Medical referrals for hypnotherapy: opinions of physicians, residents, family practice outpatients, and psychiatry outpatients

Previous studies surveying attitudes and education regarding the clinical use of hypnosis have been conducted with patient populations only. The current study was undertaken to assess the attitudes, experiences, training levels, and interest in future education regarding the use of hypnosis by staff physicians, medical resident physicians, family practice outpatients, and psychiatry outpatients. All subjects were drawn from a 400-physician group practice in Central Texas affiliated with a large university health science center. Results indicate that the majority of physicians (79%) and residents (67%) had received no prior training and even fewer had experienced hypnosis. The percentages for personal experience with hypnosis were similar for psychiatric outpatients, physicians, and residents. The need for patient and practitioner education was elucidated by the high rate of endorsement of misconceptions regarding hypnosis by patients (over half) and by some medical practitioners as well. Limited awareness of the appropriate applications of hypnosis was reported. However, 85% of practitioners expressed an interest in hypnosis education. Further research in medical setting demographics is recommended to validate generalizability of results and facilitate construction of medical education programs in hypnosis.     

Synthesis, antioxidant and anti-inflammatory activity of novel substituted ethylenediamines and ethanolamines. A preliminary quantitative structure-activity relationship study

Six substituted oxo- or hydroxy-aminoethanols and ethylenediamines were synthesized and tested as anti-inflammatory agents. 1-Substituted 4-(2-aminoethylamino)-1-butanones and 1-substituted 4-(2-hydroxy-ethylamino)-1-butanones were prepared by reacting the appropriate 4-chloro-1-butanone with the corresponding aminoalcohol or ethylenediamine. 1-Substituted 4-(2-aminoethylamino)-1-butanols were prepared by the reduction of the ketones with NaBH4 or NaBH3CN. The RM values of the synthesized compounds were determined as an expression of their lipophilicity. The effect of these compounds on in vitro non-enzymatic lipid peroxidation, their hydroxyl radical scavenging activity and their ability to interact with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH) were studied. The effect of the synthesized compounds on inflammation, using the carrageenan induced rat paw edema model was studied. Both anti-inflammatory and antioxidant activities depended on some structural characteristics of the synthesized compounds. It was also attempted to correlate the above mentioned activities with some physicochemical parameters using a quantitative structure-activity relationship approach. The primary amino group appeared to be of importance for antioxidant activity in this series of compounds.