Wind velocities on venus: vector determination by radio interferometry.

To determine the wind directions and speeds on Venus, as each Pioneer probe fell to the surface we tracked its motion in three dimensions using a combination of Doppler and long-baseline radio interferometric methods. Preliminary results from this tracking, coupled with results from test observations of other spacecraft, enable us to estimate the uncertainties of our eventual determinations of the velocity vectors of the probes with respect to Venus. For altitudes below about 65 kilometers and with time-averaging over 100-second intervals, all three components of the velocity should have errors of the order of 0.3 meter per second or less.

Plasma pregnenolone and 17-OH-pregnenolone in patients with adrenal tumors, ACTH excess, or idiopathic hirsutism.

Plasma levels of the delta5-pregnenes, pregenolone and 17-OH-pregnenolone, were measured in patients with disordered steroidogenesis. While 17-OH-pregnenolone was within the normal range in patients with hypercortisolemia due to Cushing's disease, ectopic ACTH or adrenal adenrenal adenoma, 4 of 6 patients with an adrenal carcinoma had elevated levels of this precursor. Thus, elevated plasma 17-OH-pregnenolone levels in patients with Cushing's syndrome indicate adrenal carcinoma, although a normal value does not exclude this diagnosis. Abnormal resistance of delta5-pregnenes to suppression with dexamethasone proved useful in detecting the presence of residual tumor in the post-operative evaluation of adrenal carcinoma. Basal plasma pregnenolone was within the normal range in 19 of 20 patients with Cushing's disease and was invariably normal in patients with other varieties of hypercortisolism. Since acute administration of ACTH causes marked elevation of delta5-pregnene levels while patients with chronic ACTH excess (Cushing's disease and ectopic ACTH production) have normal levels, it is suggested that ACTH has a chronic influence on the intraadrenal utilization of delta5-pregnenes in addition to stimulating their formation. In pre-menopausal women with idiopathic hirsutism, basal levels of both delta5-pregnenes were elevated (P less than 0.001). Following dexamethasone administration the absolute decrease in delta5-pregnenes levels was greater than that seen in normal subjects. This observation indicates that the metabolism of delta5-pregnenes is abnormal in patients with idiopathic hirsutism.

The pretectum mediates rapid eye movement sleep regulation by light.

A variety of sensory stimuli (e.g., visual, auditory, and thermal) are known to induce rapid eye movement (REM) sleep in mammals. Studies have examined the induction of REM sleep in albino rats by light-to-dark transitions, a phenomenon referred to as REM sleep triggering. Recent research has demonstrated that aspiration lesions of the superior colliculus (SC) and pretectal area attenuated REM sleep triggering. To define more specifically the area or areas involved in mediating REM sleep responses to changes in illumination, fiber-sparing neurotoxic lesions were made to the pretectum (PT) or the SC. Lesions of the PT attenuated REM sleep triggering, whereas lesions of the SC did not. Thus, the role of the PT may be expanded to include the regulation of REM sleep in response to photic stimulation in albino rats. These findings provide a paradigm in which to study mechanisms of REM sleep generation and the effects of light on behavioral state.

Translocation (1;17) in accelerating and blast phases of chronic myelogenous leukemia.

A translocation (1;17)(p11;q11) has been observed in two chronic myelogenous leukemia (CML) patients studied during the accelerated or acute stages of their diseases. In a review of the literature, four additional cases of t(1;17)(p11;q11) were identified, suggesting that this marker may be specific for the terminal phase of CML.

Contact thermal burns of the cornea from electric curling irons.

We treated four patients with corneal burns resulting from mishaps while using electric curling irons. In all cases, the burns were symptomatic with blurred vision, tearing, pain, and photophobia. Injury was limited to the corneal epithelium, and management included debridement, topical antibiotics, cycloplegia, and pressure patching. Burns resolved completely within 48 hours after debridement and patching.

A competitive enzyme-linked immunosorbent assay (ELISA) to detect retronecine and monocrotaline in vitro.

Antibodies to the nonesterified pyrrolizidine nucleus, retronecine (155 mol.wt), were produced in rabbits and detected using an avidin-biotin antibody ELISA. A competitive ELISA for the detection of retronecine and the cyclic diester monocrotaline was also developed using the antiserum produced against the hapten conjugate, retronecine-bovine serum albumin. Retronecine was obtained by hydrolysis of monocrotaline, succinylated and directly coupled to bovine serum albumin or ovalbumin. Antibodies to the pyrrolizidine nucleus, retronecine, can be detected within 5 min after the addition of substrate using the avidin-biotin ELISA. Competitive inhibition of antibodies to retronecine is obtained by the addition of known amounts (0-11.42 micrograms/microliters) of either the homologous antigen, retronecine, or the heterologous antigen, monocrotaline, however, retronecine acts as the better competitor.

Effect of hypothermic perfusion on corneal endothelial morphology.

The effect of moderate in-vivo hypothermic perfusion on corneal endothelial integrity was studied in the cat. Eleven cats underwent in-vivo anterior chamber perfusion for 30 minutes with either normothermic (23 degrees C) or hypothermic (5 degrees C) perfusate. Corneas were then evaluated clinically (biomicroscopy), functionally (vital staining), and morphologically (scanning electron microscopy) for changes attributable to hypothermic perfusion. All 3 modes of evaluation suggested no difference in corneal endothelial integrity under the 2 experimental perfusion conditions. At the clinical and scanning electron microscope levels hypothermic perfusion does not show any effects on the corneal endothelium. Regional hypothermia is of theoretical and potential utility in procedures involving prolonged intraocular perfusion.

The effect of prolonged exposure to industrial noise on otosclerosis.

More than 3000 workers referred by the Workmen's Compensation Board of Ontario have been evaluated for pension for industrial hearing loss. They include the normal proportion of otosclerotics, many of whom have had surgical therapy. The operations have been done by a wide variety of surgeons in the province of Ontario, and the results are representative of those which will be obtained in a large section of the Canadian community. The results are significantly worse than generally quoted, and some of the deficiencies are attributable to occupation. These include perilymph fistula from excessive straining and sensorineural hearing loss due to noise exposure. Detailed results will be presented.

A rapid spectrophotometric method for the determination of esterase activity.

We have developed a spectrophotometric assay method which continuously records esterase activity at 510 nm by monitoring absorbance changes due to the formation of a diazo dye complex. In our method, alpha-naphthyl ester substrates are hydrolyzed by enzymatic action to alpha-naphthol which couples to Fast Blue RR salt (a diazonium salt) forming a diazo dye complex. Our method is unique in directly monitoring the formation of the diazo dye complex without extracting the color of the complex as in other methods that use naphthyl esters and diazo coupling of reaction products. The method appears to be limited to alpha-naphthyl ester substrates, however, since beta-naphthyl esters did not give a linear change in absorbance in the enzymatic reactions tested. With this assay method, one can use a single substrate both to determine esterase units quantitatively in solution and to detect esterase staining activity on gel electrophoresis.

A validated high-performance liquid chromatographic method for the determination of atenolol in whole blood.

A validated reversed-phase high-performance liquid chromatographic (HPLC) procedure employing fluorescence detection for the analysis of atenolol (Tenormin) in human whole blood is reported. The method is rapid and coupled with standard HPLC procedures leads to a sensitive, accurate and reproducible assay. The retention times of atenolol and internal standard, bamethan, are 4.4 and 6.3 min, respectively. The peak height ratio versus plasma concentration is linear over the range of 20.0-800 ng ml-1, with a detection limit below 10 ng ml-1. The mean absolute recovery of atenolol using the described assay is 90%. The inter- and intra-day accuracy and precision are within 8% of the actual values for all concentrations investigated. Furthermore, this procedure was applied to the analysis of whole blood samples from healthy subjects receiving a single 100 mg oral dose of Tenormin.

High-performance liquid chromatographic assay for the derivatized enantiomers of propranolol and 4-hydroxypropranolol in human plasma.

A stereospecific method for the analysis of propranolol and 4-hydroxypropranolol in human plasma employing fluorescence detection has been developed using the homochiral derivatizing agent 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (TAGIT). The use of fluorescence detection provided enhanced sensitivity and cleaner chromatograms for the analysis of plasma samples, when compared to UV detection. Furthermore, parameters such as TAGIT concentration, vortex time and reaction time were examined to optimize conditions for maximum derivatization recoveries. The analyses of S(-)- and R(+)-propranolol from plasma were linear over the concentration range of 2.0-200 ng ml-1, while S(-)- and R(+)-4-hydroxypropranolol were linear from 5.0 to 200 ng ml-1.

Effect of water content in perchloric acid on the non-aqueous potentiometric titration of nitrogen-containing compounds.

In the United States Pharmacopeia (USP), 0.1 N perchloric acid in acetic acid volumetric solution (hereafter HClO4 VS) used for non-aqueous titration has specified a water content between 0.02 and 0.05%. Preparing this titrant with such a narrow range of water content is very time consuming, precludes the use of commercially available titrants, and, consequently, prompted an investigation to try and expand the range up to 0.5%. In this study, the titrimetric results obtained using HClO4 VS containing more water were very close to those obtained using the USP specified titrants. A maximum assay difference of 0.7% in the titrations of three selected nitrogen-containing compounds, clonidine hydrochloride, dipyridamole, and adenosine were observed. The titrimetric results obtained using these titrants were also precise with RSDs of not more than 0.4%. Therefore, a wider range of water content in HClO4 VS between 0.02 and 0.5% is suggested for the USP potentiometric titration of nitrogen-containing compounds.

Vagal paraganglioma: the Jefferson experience.

Vagal paraganglioma is a rare tumor of neural crest origin. Although the literature is in agreement with regard to epidemiology, diagnosis, and tumor biology, there is some controversy over treatment modalities for these patients. We performed a nonrandomized retrospective study in a large single-institution series of patients (n = 19) in whom vagal paraganglioma was diagnosed. General statistics included age, male/female ratio, tumor size, and duration of follow-up. Other variables such as signs and symptoms at presentation, family history, multicentricity, metastatic disease, and secretion of catecholamines were included. CT scan, MRI, and angiography were used in combination for diagnostic purposes as well as for treatment planning. Preoperative embolization was performed in 5 of the more recently treated patients. Current issues regarding the use of preoperative embolization and choice of surgical approach were analyzed. In this article the possibility and sequela of vagus nerve-sparing procedures will be presented. Operative complications and postoperative morbidity related to cranial neuropathies will be discussed. The rationale for performing adjunct procedures, including cricopharyngeal myotomy and vocal fold medialization, to facilitate the rehabilitation of patients with postoperative cranial nerve deficits will be given. Our findings and recommendations will be compared with currently accepted treatment protocols in conjunction with a review of the literature.

Willingness to treat HIV-positive patients at different stages of medical education and experience.

The willingness of physicians to provide care to HIV-positive patients has been linked to a number of attitudinal factors, but little is known concerning the impact of premedical, medical, and residency training on these factors. The purpose of this study is to elicit responses to the same series of questions concerning HIV and its treatment from respondents at different stages of training, to detect trends in attitudes and to measure the impact of those attitudes on willingness to provide care for HIV/AIDS patients. Study data come from a cross-sectional survey (n = 249) of respondents across the training continuum, from premedical students to faculty physicians, using a self-administered questionnaire at a single medical school. The response rate was 59.6%. The study showed significant decreases in personal fear and misgivings concerning HIV, coupled with a substantial decrease in the perceived need for testing of non-high-risk individuals, as respondents gained additional education and training. Overall, the intent to treat HIV did not change significantly by training level, but multivariate analyses showed that while the initially strong influence of attitudes toward AIDS and its attendant risks diminishes, comfort relative to being around homosexuals per se continues to exert an impact on the intent to treat. Appropriate use of protective measures when providing care becomes far more common once individuals enter their clinical training years. The impact of medical education through its entire continuum therefore shows a positive impact on attitudes toward HIV, despite the absence of a significant trend in respondents' stated intent to treat. However, negative attitudes toward homosexuals continue to exert a negative influence on intent to treat that endures into the clinical training years.

A light and electron microscopical study of intranuclear cytoplasmic invaginations in interstitial cell tumours of dogs.

Intranuclear cytoplasmic invaginations, so-called "pseudoinclusions", were seen in all 7 interstitial cell tumours identified among 32 consecutive canine testicular tumours examined. The proportion of cells with intranuclear cytoplasmic invaginations varied from less than 1 per cent to 15 per cent. Similar "pseudoinclusions" were not seen in any other canine testicular tumours examined; this finding might be helpful in differential diagnosis, especially in less differentiated tumours. Histologically, the cytoplasmic invaginations appeared as round, eosinophilic, clearly demarcated intranuclear inclusions and stained with periodic acid-Schiff. Affected nuclei were enlarged. The process of progressive cytoplasmic invaginations into the nucleus and replacement of most of the nuclear volume of the neoplastic interstitial cells with cytoplasmic material was examined by transmission electron microscopy. Two or more cytoplasmic invaginations were sometimes present within a single nucleus. The nuclear membrane could be followed continuously around the cytoplasmic invaginations and nuclear pores were present in the membrane covering invaginations. The invaginations contained smooth and rough endoplasmic reticulum, vesicles, lipid vacuoles, myelin figures and disrupted membranous profiles. Bundles of interwoven cytoplasmic filaments were among the organelles seen in the invaginations in one tumour. Possible reasons for the formation of intranuclear cytoplasmic inclusions are discussed and maintenance of the normal ratio of nuclear surface to nuclear volume is suggested as the mechanism promoting formation of inclusions in interstitial cell tumours.

Ultrastructural assessment of a blastocyst recovered from a cow with subclinical purulent endometritis.

A blastocyst was recovered from a cow with subclinical purulent endometritis from which Actinomyces pyogenes was isolated. Ultrastructurally the blastocyst appeared viable, although the zona pellucida and pervitelline cell debris were undergoing phagocytosis by neutrophils. An increase in lysosomal activity was observed in the inner cell mass, which may represent sublethal injury due to inflammatory alteration of the uterine milieu. It was concluded that the embryo was resistant to the bystander effect of the suppurative inflammation but that the altered uterine microenvironment may have caused sublethal blastocyst injury.

The recovery of ureaplasmas from bovine embryos following in vitro exposure and ten washes.

Twenty-six unhatched embryos and ova were exposed to Ureaplasma diversum strain 2312 in vitro for 16 h and subsequently washed ten times. Fifteen of the embryos and their wash fluids were cultured for ureaplasmas. Of the remaining 11 embryos, six were incubated with rabbit anti-Ureaplasma immunoglobulin (RAI) and five were incubated with serum from naive rabbits(NRS), after which all were incubated with protein A gold and prepared for electron microscopy. On ultrastructural examination, ureaplasmas were observed on the outer surface of the zona pellucida of all 11 embryos. The ureaplasmas on the six embryos incubated with RAI were labeled with gold particles, while those on the five embryos incubated with NRS were not labeled. Ureaplasmas were recovered from all 15 of the cultured embryos and all of the first and second wash fluids as well as intermittently from the third, fourth, sixth, seventh, eighth and ninth wash but not fom the fifth or tenth wash. It was concluded that viable ureaplasmas adhered to the zona pellucida during in vitro exposure of bovine embryos and were not removed by ten washes.

Bovine abortion and neonatal death associated with Ureaplasma diversum.

Ureaplasma diversum was isolated from the lungs and/or stomach fluid and placentas of five aborted bovine fetuses and four newborn calves. All isolates were serotype D48. Placentitis was observed in all instances in which the placenta was examined. Gross lesions consisted of focal or diffuse reddening of the chorioallantois and amnion and thickening of the amnion. Microscopically there were fibrosis, edema and inflammation of the amnion. Microscopic lesions in the lung consisted of diffuse pneumonitis with thickening of the alveolar walls and in some cases peribronchiolar lymphoid accumulations. Macrophages and granulocytes were present in the alveoli. Inoculation of the vulva of a virgin heifer with one of the isolates from a fetal lung produced hyperemia and profuse purulent discharge with slight granularity.

The effects of Ureplasma diversum inoculated into the amniotic cavity in cows.

Ureaplasma diversum was inoculated into the amniotic cavity in four cows. Two calves were aborted and two were born alive. One of the latter died shortly after birth and the other was killed. The cows remained clinically normal except that three retained their placenta. On microscopic examination there was a severe placentitis and an alveolitis was present in the lungs of all calves. Ureaplasma was recovered from four placentas and three lungs. Cows remained infected for a maximum of 132 days following inoculation and the organism was recovered in urine and vulvar swabs for a maximum of 17 and 60 days respectively following expulsion of the calf. Ureaplasma diversum has been isolated from natural cases of abortion with similar lesions. This experiment strongly supports a causal relationship between abortion, birth of calves with pneumonia and U. diversum infection.