A peptidergic circuit for reproductive behavior

A projection from the medial amygdaloid nucleus to the hippocampus and septum probably uses vasopressin as a transmitter. The nucleus synthesizes vasopressin and activation of the nucleus has a hippocampal effect that is completely blocked by a vasopressin antagonist. The afferent and efferent projections of this peptidergic nucleus suggest a possible role for the system in sexual behavior. Stimulation of the nucleus inhibits the output of the hippocampus in both genders and reorganizes behavior for a period of 15-20 min. In males, the effect of peptidergic activation is to produce a behavior that resembles the post-ejaculatory interval in coitus. This state is characterized by an EEG that resembles slow-wave sleep and by ultrasonic vocalizations at a characteristic frequency of 22 kHz. Castration in either gender causes depletion of the peptide from the target fields and eliminates the peptidergic signal in the hippocampus after about 15 weeks. The effects of castration in males can be reversed by testosterone replacement. The fluctuation of estrogen levels in rat plasma during the estrus cycle happens too quickly to impact the peptidergic system, and thus there is no significant change in the strength of the peptidergic signal among the proestrus, estrus, metestrus and diestrus stages. This fact permits study of the physiology of the system without concern for stage of estrus but does not permit conclusions regarding its function in females.

Peptidergic transmission in the brain. V. Systemic correlates of central activation

Inhibition of the hippocampus by the medial amygdala is mediated by vasopressin-like peptide. Because vasopressin has action on the periphery as well as the brain, we conducted experiments to evaluate the relationship between possible peripheral actions and the central effects of the endogenous peptide. In the acutely anesthetized rat, peptide-mediated inhibition of the hippocampus is not associated with significant changes in heart rate, blood pressure or body temperature. Peripheral injections of peptide agonist fail to evoke the central inhibition, and peripheral injections of peptide antagonist fail to block the central inhibition. Stimulation of central nuclei that contain vasopressin or a similar peptide also fail to duplicate the effect of stimulating the amygdala. We conclude that the peptidergic transmission is independent of peripheral causes or correlates.

Peptidergic transmission in the brain. VI. Behavioral consequences of central activation

Having described a peptidergic transmitter system in the rat brain, we now begin to evaluate its behavioral function. We stimulated cell bodies in the medial amygdaloid nucleus (AME) with indwelling bilateral electrodes. These cell bodies contain a vasopressin-like peptide and send fibers to the hippocampus where the peptide is released upon stimulation. There the peptide inhibits hippocampal output in the awake rat just as it does in the anesthetized rat and in the rat brain slice. The stimulation reorganizes behavior with the same latency and duration as the hippocampal effect. For about 15-20 minutes after the brief stimulus, rats remain motionless with eyes wide open. This "freezing" state is punctuated by episodes of exploratory behavior. The stimulus appears to have a positive affective quality. Review of the literature in light of the present results indicates a probable role for this peptidergic system in the generation of sexual behavior in male rats.

Room-temperature microparticle-based persistent spectral hole burning memory

We show both theoretically and experimentally that a random distribution of spherical microparticles may be used as a spectral hole burning memory. This microparticle hole burning memory, which can be both written and read at room temperature, is a direct consequence of the properties of morphology-dependent resonances of microparticles.

Peptidergic transmission in the brain. IV. Sex hormone dependence in the vasopressin/oxytocin system

The medial amygdaloid nucleus (AME) synthesizes a peptide similar to arginine vasopressin and projects peptidergic fibers to the ipsilateral hippocampus in the male rat. In previous studies, we have shown that the peptide acts as a transmitter and, using in vitro and in vivo electrophysiology, we have characterized its mechanism of action. Previous anatomical work has shown that the peptidergic fibers are more dense in male rats than females and are obliterated entirely by castration. Here we report the results of our attempt to find an electrophysiological correlate of these anatomical findings. First, we show specific mediation by a vasopressin- or oxytocin-like peptide by use of a structural vasotocin antagonist. Then we show that castration obliterates the peptidergic signal in males. However, we were unable to find any sex difference that corresponded to the male/female disparity noted in the density of the peptidergic fibers. The strength, nature and stimulus-response characteristics were the same between males and females. Apart from a very subtle difference in the duration of the signal, no physiological correlate of the sexual dimorphism could be found with our techniques. We conclude that the neurophysiology partly complements the anatomy and biochemistry of this system.

Electric-field-modulated light scattering near a morphological resonance of a trapped aerosol particle

We describe electric-field-induced fluctuations in the elastic scattering near optical resonances of a spherical aerosol particle trapped at the null point of an electrodynamic levitator. The particle is apparently driven into a quadrupolar distortion by the electromechanical stress at its surface. Our results coupled with recent theory indicate that the effect is principally due to a modulation in the frequencies of individual optical resonances, that a coherent distortion smaller than one part in 10(5) ( approximately 0.1 nm) is detected, and that the effect may be used for a continuous probe of surface tension and bulk viscosity.

Optical bistability of an aqueous aerosol particle detected through light scattering: theory and experiment

We present a catastrophe-based graphic model for understanding the optical bistability (OB) of an aqueous aerosol particle detected in light scattering. The model is shown to be in good agreement with hidden resonance experiments and indicates that OB in such particles can occur at an incident power level of <50 x 10(-9) W. This threshold is controlled principally by the quality factor of morphological resonances and thermophysical properties of the particle. A catastrophe scheme for the bistability of solid particles is anticipated.

Impact of geriatric nurse practitioners on nursing-home residents' functional status, satisfaction, and discharge outcomes

This study evaluated the impact of geriatric nurse practitioners (GNP) employed by nursing homes on quality of patient care and residents' outcomes during a 12-month study period. Quality of care was assessed in standardized interviews of 525 residents in five nursing homes with GNPs and 323 residents in five other nursing homes without GNPs. Each resident was interviewed up to four times during the study period (at baseline, and 3, 6, and 12 months later) to determine functional status, satisfaction with care, and physical condition at each of these points. The only significant difference between groups was that fewer newly admitted residents were hospitalized from GNP homes than from those without a GNP. The results of this interview study showed that the GNP as a nursing home employee had little impact on residents' functional status, physical condition, or satisfaction.

Career paths of geriatric nurse practitioners employed in nursing homes

The career paths of geriatric nurse practitioners (GNPs) trained with support from the W. K. Kellogg Foundation through the Mountain States Health Corporation (MSHC) were studied. Under this program, GNPs were recruited from sponsoring nursing homes and returned to GNP positions in the sponsoring facilities following training. Training was carried out under a continuing education model offered through six university-based schools of nursing. Questionnaires were sent to the 111 GNPs trained. Of the 102 respondents, 97 provided complete information about past and present education, work experience, and job functions. The GNPs were women with a median age of 45 years, and they were employed in rural settings in the western United States. More than 45 percent of the nurses had at least a baccalaureate degree at the time of GNP training. The GNPs remained employed in long-term care positions that implemented the practitioner role. The median length of GNP employment in their first jobs after training was more than 4.5 years. The resignation rate from this first position was 1.66 resignations for each 10 years of GNP employment. Job changes were likely to be attributed to organizational changes with subsequent positions shifting toward a diversification of the GNP role. The study demonstrates the success of the MSHC program in introducing and retaining GNPs in nursing homes.

Treatment of urinary incontinence in dogs by endoscopic injection of Teflon

Twenty-two dogs with urethral sphincter incompetence, nonresponsive to phenylpropanolamine administration, were treated by urethral submucosal injection of Teflon. Urinary continence was achieved in all dogs for at least 2 months. Urinary incontinence recurred in 14 dogs (64%) and was controlled by a second Teflon injection in 11 of 12 dogs (92%). Minor complications included transient stranguria, with or without hematuria, after 4 of 35 injection procedures. One dog had temporary partial urethral obstruction after treatment.

Energy transfer and the photon lifetime within an aerosol particle

The theory of enhanced energy transfer within an aerosol particle based on donor coupling to morphological dependent resonances is tested for the first time to our knowledge. The correspondence between theory and experiment is good and allows one to obtain the photon lifetime within the longest-lived resonances. A comparison between this lifetime and the lifetime as obtained by Mie theory is discussed.

Dose to the cardiac vascular and conduction systems in primary breast irradiation

Using computerized tomography (CT) in which cardiac anatomy was defined, doses delivered to the cardiac compartments, vascular and conduction systems were assessed for various standard techniques of primary breast irradiation. Included in the analysis were 6 MV photon tangents (T) alone, or in conjunction with a separate internal mammary field (IMF). Beams evaluated in the IMF were 6 MV photons, 12 MeV electron beam, and mixed photon/electron beam; Cobalt 60 was also analyzed as an alternate photon beam. Treatment of the IMF with photons, either alone or in combination with electron beam, delivered doses ranging between 30 Gy to 50 Gy to all chambers of the heart, coronary arteries and branches of the conduction system. Complete sparing of the posterior cardiac structures and volume is accomplished with treatment plans using tangents alone or in combination with 12 MeV electron beam irradiation to the IMF. Sparing of the anterior wall of the left ventricle, Bundle of His and left anterior descending coronary artery is also achieved in treatment with tangents and 12 MeV electron beam IMF. Doses to this region with tangents alone ranged from 20 Gy to 45 Gy compared to 0 to 30 Gy with tangents and 12 MeV electron beam IMF. Clinical significance of these findings will be discussed.

Periarticular soft tissue calcification and ossification in the septic joint

We encountered three infants who developed juxta-articular calcification adjacent to the anterolateral aspect of the ilium. All had had drainage of a septic hip using an anterior approach. Calcification was not found among five infants whose septic hips were drained using a posterior approach. Some surgeons who employ the anterior approach facilitate exposure of the joint capsule by elevation of the origins of the sartorius and rectus femoris muscles. We feel this juxta-articular calcification in this setting is a sequla of anterior surgical drainage of the hip in which there has been surgical elevation of the iliac periosteum. It does not imply an unfavorable outcome.

A comparison of prednisolone with azathioprine and prednisolone with intramuscular gold in rheumatoid arthritis

Pulse prednisolone hemisuccinate therapy (500 mg given intravenously on three occasions over two weeks) has been combined with either intramuscular sodium aurothiomalate or azathioprine in an assessment of 30 patients with rheumatoid arthritis. Significant improvement in a variety of clinical and biochemical assessments was seen in both groups. Both treatments were well tolerated by the patients and prednisolone appeared to accelerate the response to sodium aurothiomalate and azathioprine but there was no great evidence that it enhanced it.

Determination of molecular orientation at the surface of an aerosol particle by morphology-dependent photoselection

The orientation of fluorescent molecules on the surface of an aerosol particle has been determined by using a new technique, morphology-dependent photoselection. The excitation spectrum of the angularly averaged fluorescence from a single levitated particle is measured by using an integrating sphere levitator. By utilizing the relative intensities of resonant peaks in this spectrum and knowledge of the polarization properties of different resonances, we show that the orientation of molecules relative to the surface normal may be obtained.

A method of quantify confounding in regression analyses applied to data on diet and CHD incidence

We present a method to display the results of linear regression when the independent variables are highly correlated. In this method the sum of squares of regression (SSR) for pairs of variables are partitioned into orthogonal and shared components. A shared component is the reduction in the SSR of one of the variables when the other variable is added to the regression equation. This method shows how the SSR for one variable depends on the other variables present in the regression equation and explains apparent inconsistencies between forward and backward stepwise regression. To demonstrate the potential usefulness of this method we reanalyzed previously reported data on the relationship between coronary heart disease (CHD) and diet. The analysis suggested that carbohydrate and alcohol intake are negatively associated with CHD because they are associated with greater caloric intake. Protein and fat intake are also associated with greater caloric intake, but in addition they are associated with factors that increase the risk of CHD.

Community outbreak of adenovirus type 7a infections associated with a swimming pool

In July 1982, an outbreak of pharyngitis caused by adenovirus type 7a occurred among children in a small town in western Oklahoma. Predominant symptoms were fever and sore throat (by case definition), headache (83%), abdominal pain (64%), and conjunctivitis (51%). At least 77 persons were identified whose symptoms met the case definition for illness. Onsets of illness peaked during the week of July 5 to 12, and the outbreak resolved within three weeks. A systematic telephone survey of the town revealed that persons who had swum at the community swimming pool were more likely to be ill than those who had not (P less than .001). A second survey of families with season passes to the pool showed that among swimmers, illness was directly related to average number of hours of exposure to the pool each week (P less than .001 by chi-square for trend). In addition, swimmers who reported swallowing pool water were more likely to be ill (29 of 56, 52%) than persons who did not (ten of 41, 24%) (P = .01). Throat-swab specimens from five of seven ill persons (71%) grew adenovirus 7a compared with one of 12 well persons (8%) (P = .01). The pool chlorinator had reportedly malfunctioned during early July. The outbreak resolved with proper operation of the chlorination system. Swimming pools continue to be a potential source of community-wide outbreaks of adenovirus infections.

Optical bistability of an aerosol particle

The optical bistability of an aerosol particle is reported for the first time to the authors' knowledge. The mechanism for the effect is associated with the photothermal evaporation that accompanies the visible absorption by structure resonances.

Impending cardiac herniation: the snow cone sign

Two cases of cardiac herniation and volvulus that occurred after right pneumonectomy are presented. Both asymptomatic patients demonstrated an unusual bulging contour to the right side of the heart on radiographs obtained in the recovery room, before complete herniation and volvulus occurred. In an autopsy preparation, a similar right contour was produced after partial cardiac herniation through a pericardial defect. The hemispheric contour from partial cardiac herniation resembles the shape of a snow cone. Clinical awareness of this sign of impending herniation is important, so risk factors known to produce herniation may be modified.

[Diagnostic and prognostic significance of so-called rheumatoid vasculitis--2]

51 patients with rheumatoid arthritis and high rheumatoid factors (mean titres 928) underwent examination for the demonstration of an extraarticular organ manifestation within the scope of the cooperation between the Department of Medicine of the Karl-Marx-University Leipzig and the Institute for Rheumatology of the Academy of Medical Sciences of the USSR in Moscow. The frequency of nodous rheumatism (about 60%) is comparable with the frequency of polyneuropathy. In 20% of the patients a systemic muscle atrophy, a hepatomegaly as well as a Raynaud-syndrome were stated. By means of skin biopsy in 28% perivascular infiltrates were found. Altogether in 6 patients (12%) a participation of the lungs and the pleura, respectively, could be proved. Only rarely a clinically manifest heart disease caused by the rheu-we we found an pericardial effusions in 3 cases. In systemic manifestation, such as myositis, participation of the eyes or vasculitis of the digital arteries with necrosis, were only sporadically to be established. Among 22 patients we found an pericardial effusions in 3 cases. In systemic manifestation in most cases increased parameters of activity were found. From the practical point of view apart from increased titers of the rheumatoid titres and circulating immune complexes (C1q-BT) increased concentrations of the C-reactive protein are prognostically significant. The presence of high rheumatoid factor titres alone as well as the isolated presence of rheumatic nodes must not always be connected with an unfavourable prognosis. When severe extraarticular manifestations are present a possibly early, intensive occasionally extracorporeal treatment is indicated.

Comprehensive model of the photophoretic force on a spherical microparticle

The photophoretic force is described by a comprehensive model containing aspects of both the optical local-field and gas-dynamic properties. It is shown that the model is in good agreement with detailed experimental data and provides a new means for measuring optical constants of microparticles.

Molecular spectroscopy of a single aerosol particle

The absorption spectrum of a single micrometer-sized aerosol particle is measured for the first reported time in the IR. Particle absorption is determined through the IR modulation of visible scattered light near a structure resonance. This technique, termed structure resonance modulation spectroscopy, is used to measure the IR absorption spectrum of an (NH(4))(2)SO(4) aerosol droplet of 5.4-microm diameter in the region from 970 to 1280 cm(-1). The resulting spectrum, when fitted by Mie theory, enables one to determine the molecular composition of the droplet.

Insulin infusion in conscious dogs. Effects on systemic and coronary hemodynamics, regional blood flows, and plasma catecholamines

Cardiovascular actions of insulin were studied by intravenous infusions of insulin (4 and 8 mU/kg per min) in normal conscious dogs. This resulted in increases in cardiac output, heart rate, and left ventricular derivative of pressure with respect to time (dP/dt) and dP/dt/P, as blood glucose was reduced. The inotropic and chronotropic effects of insulin were not related to hypoglycemia, as they persisted even when blood glucose was restored to control values or when it was prevented from falling by a simultaneous infusion of glucose. These cardiac effects were accompanied by increases in plasma catecholamines, and were abolished by propranolol pretreatment. Both plasma epinephrine and norepinephrine increased during insulin hypoglycemia, but only norepinephrine increased during insulin infusion when euglycemia was maintained. Mean arterial blood pressure did not change significantly during insulin hypoglycemia, but rose if euglycemia was maintained, probably due to the selective increase in norepinephrine in the latter condition. A pressor response also occurred in propranolol-pretreated dogs during insulin hypoglycemia, but was abolished when the animals also had been pretreated with phentolamine, indicating that the vasoconstrictor action of insulin was mediated via alpha adrenergic receptors. Insulin infusion increased left ventricular work and myocardial blood flow in dogs with and without hypoglycemia. Myocardial blood flow, however, did not change significantly during insulin infusion in dogs pretreated with propranolol. As propranolol also diminished the inotropic response, it appears that the increase in myocardial blood flow caused by insulin in the normal dog is causally related to the increased myocardial metabolic demand. Insulin also produced vasomotor effects on other vascular beds. In skeletal muscle, blood flow was increased under all study conditions, except during insulin hypoglycemia after propranolol-pretreatment when unopposed alpha-mediated vasoconstriction was present. The persistent increase in flow during both alpha and beta adrenergic blockade suggests that insulin has a direct dilator effect on skeletal muscle vasculature. In the adrenal gland, flow was increased except during euglycemia, when no rise in plasma epinephrine was observed, suggesting coupling between adrenal flow and catecholamine release. In the splanchnic bed, flow was decreased during euglycemia, when plasma norepinephrine rose, and during beta adrenergic blockade with propranolol, when unopposed alpha-mediated vasoconstriction also predominated. A similar pattern was found in the kidney, except that renal blood flow also fell after combined alpha and beta adrenergic blockade. The results show that the vasomotor effects on regional flows are mediated both via adrenergic mechanisms, and in the case of skeletal muscle and kidney, via mechanisms unrelated to sympathetic stimulation.

Aspects of intestinal parasitism in villagers from rural peninsular India

In 1977, a parasitological survey was undertaken of stool samples collected from 335 people from 5 villages in semi-arid regions of peninsular India. Stools, which were collected from various individuals in a stratified sample of 40 matched households from each village, were examined by standard diagnostic procedures. Eggs of Ascaris lumbricoides and protozoan cysts, which were identified on morphological grounds as belonging to Entamoeba spp., were most common. Other protozoan cysts were considered to be those of Balantidium coli, and eggs of hookworm and Hymenolepis nana were also observed in some of the stool specimens. The prevalence of parasitic infections varied between villages. The village with the highest prevalence of Ascaris (70%) appeared to have the greatest demands made on its meager drinking-water supply. This village is located in a dry, windy and dusty region and it is speculated that, in addition to well-established transmission mechanisms, the villagers may be exposed, perhaps through contamination of uncovered drinking-water wells and inhalation, to wind-borne Ascaris eggs. In 1967, a WHO Expert Committee Report on the Control of Ascariasis pointed out that information on the frequency of dust-borne infection with Ascaris in man was inadequate.

Hemodynamic effects of prazosin in chronic heart failure

Three series of investigations were carried out with prazosin (PZN) hydrochloride. In the first, hemodynamic effects of PZN were compared with those of hydralazine (HDZ) in 11 patients with chronic congestive heart failure (CHF). In doses up to 5 mg, PZN increased cardiac output (CO) 20% accompanied by a 20% decrease in pulmonary capillary wedge pressure (LVFP). HDZ increased CO by 50% with little or no effect on LVFP. An additional 12 patients were given multiple 5 mg doses of PZN at 6-hour intervals with measurements of hemodynamic and plasma blood levels. Results suggested an attenuation of the effects of PZN on increasing CO but not on decreasing LVFP. This attenuation of CO was not due to inadequate plasma levels. Acute exercise studies (supine bicycle) were performed in 10 patients with severe CHF before and after the administration of several doses of PZN. There appeared to be a greater effect of PZN during exercise than at rest, with a beneficial increase in CO and reduction in LVFP. These data suggest that, despite hemodynamic attenuation of its effects on CO at rest, PZN may still be beneficial to active patients with CHF. In vitro studies with various vasodilators were performed to evaluate potential intropic effects. Isometric force (cat papillary muscle) increased 2% with 10-4M and 31% with 10-3M HDZ. PZN increased force 4% at 10-6M and 18% at 10-4M. Captopril did not increase force development at any dose level. The doses of HDZ and PZN that increased force development were higher than usual clinical doses.

Contrast enhancement of thallium-201 myocardial scintigrams: improved sensitivity with diminished specificity in coronary disease detection

Thallium-201 myocardial scintigraphy (TMS) has become an increasingly popular noninvasive technique with a high diagnostic specificity, but a somewhat lower sensitivity for coronary disease (CAD) detection. Many centers now routinely employ computer techniques to contrast enhance scintigrams, but the resulting changes in sensitivity and specificity have not been carefully evaluated. In the present study, three observers with different levels of experience blindly interpreted both unprocessed and enhanced exercise TMS from 40 patients with CAD and from 15 without significant obstructions. The sensitivity for CAD achieved by each observer was higher with the enhanced scintigrams (increase from an average of 80% to 93%), but there was concomitant loss of specificity (from 93% to 73%). Similarly, significant changes were present in the sensitivity and specificity with which ischemic regions were diagnosed. In addition, contrast enhancement facilitated interpretation of TMS studies, particularly in making comparisons between exercise scintigrams and subsequent rest or redistribution images. Contrast enhancement affected the interpretations of the inexperienced observer most significantly. We conclude that contrast enhancement improves TMS sensitivity but results in some loss of specificity. The variable effect of enhancement on observers with different levels of experience suggests that laboratories should critically evaluate their own results before routinely employing computer processing.

Diastolic aortic root motion in left ventricular hypertrophy

The echocardiographic motion of the aortic root reflects, in part, left atrial filling and emptying. The echocardiograms of 60 patients with left ventricular hypertrophy (LVH) secondary to aortic stenosis, hypertrophic subaortic stenosis, and hypertension were compared with those of 36 normal subjects to determine whether the alterations of early rapid diastolic filling associated with LvH would alter motion of the posterior aortic root. Patients with LVH had a characteristic echographic pattern of motion of the posterior aortic root manifested by the attenuation of normal abrupt diastolic posterior aortic root motion. The atrial emptying index (AEI), defined as the fraction of passive posterior aortic wall motion occurring in the first third of diastole, was significantly reduced in patients with LVH (p less than 0.001), but did not discriminate among mild, moderate, and marked hypertrophy. The AEI may be useful in the identification of altered left ventricular filling associated with LVH. The changes associated with a decreased AEI are readily appreciated by visual inspection and provide a rapid method of qualitatively assessing left ventricular filling properties.

Changes in the food intake and body weight of protein-malnourished rats infected with Nippostrongylus brasiliensis (Nematoda)

The daily food intake and related changes in body weight were measured in young rats which were fed on synthetic diets containing 1% (3 experiments), 2% (4 experiments) and 20% (1 experiment) casein respectively. Some rats were infected with Nippostrongylus brasiliensis and allowed to feed ad libitum, some remained uninfected and were allowed to feed ad libitum, while others, which were matched by initial weight with rats from the infected group, remained uninfected and were given only the same amount of food as that consumed during the previous 24 h by their infected partners. No significant differences were detected between the rats before the start of the infection. Thereafter, the food intake of the infected undernourished rats was usually found to be significantly lower and the loss of body weight significantly greater than those of the uninfected rats. In infection periods of relatively long duration, the pair-fed uninfected rats did not lose as much weight as their infected partners even though their food intake (1% and 2% casein) was the same. Although the food intake, and consequently the weight, of infected rats fed on the diet containing 20% casein were significantly less than in their uninfected partners, no significant differences were observed between the weights of the infected and pair-fed rats fed on this diet.

Caecal growth in the domestic fowl following surgical manipulation

1. Some effects of removing increasing proportions of the left caecum on the remaining caecal tissue and on the right caecum were studied in young chicks during a period of 35 d. The chicks were 22 d old when the operations were carried out. 2. No differences were detected between the gains in weight of the control and experimental groups of birds. 3. A marked negative linear relationship was observed between the dry weight of the amount of caecal tissue removed when the birds were 22 d old and weight of the left caecum at the end of the experiment. 4. The average growth rate of the left caecum (g dry tissue/week) was found to be dependent on the estimated weight of caecal tissue remaining after surgery. 5. No evidence was obtained to indicate that the growth of the right caecum responded to the removal of the left caecal tissue. 6. The morphology and histology of the operated caeca were found to be similar to the equivalent regions of the unoperated caeca. Surgical interference was not followed by any major changes in mucosal architecture. 7. In birds which had experienced unilateral caecectomy, the discharge of caecal faeces usually stopped for about 2 d. When caecal defaecation was resumed, the pattern of defaecation appeared to be the same as that observed in sham-operated birds with both caeca intact.

Altered prazosin pharmacokinetics in congestive heart failure

The pharmacokinetics of prazosin (Minipress) were studied in nine patients with NYHA Class 3 or 4 congestive heart failure and in five healthy controls. After a single 5 mg oral dose, plasma concentrations of prazosin, as reflected in the area under the plasma concentration-time curve (AUC) and prazosin plasma half-life, were approximately double in the patients in comparison to the control group. Reduction in hepatic blood flow, altered gastrointestinal absorption of the drug or diminished intrinsic hepatic metabolic activity in the patient group may have contributed to the observed changes in prazosin disposition. The finding of higher prazosin plasma concentrations in patients with refractory heart failure demonstrates the need for close monitoring of these individuals following administration of the drug in the treatment of chronic congestive heart failure.

Broadband photophoretic spectroscopy

A means for obtaining broadband photophoretic spectra is described. The sensitivity of the technique is found in accordance with radiometric theory to increase markedly with pressure reduction below 1 atm. Noise oscillation induced by radiometric torques is contained through the use of electronic damping. The first broadband spectrum on a single crystallite (approximtely 5 microm) of CdS is presented.