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PubMed1976

Experimental pyelonephritis: the effect of chronic active pyelonephritis on renal function.

In these experiments, renal function in chronic active pyelonephritis was investigated and the effect of antibiotic treatment and elimination of infection on the gross pathology, histopathology and renal function in animals with chronic pyelonephritis was determined. A severe loss of urine concentrating capacity was demonstrable when the maximum urinary osmolality of a group of animals with pyelonephritis was compared with control animals. Concentrating capacity decreased sharply over the first month but further loss over an eight-month period was minimal. A compensatory increase in the glomerular filtration rate (GFR) in the control, nonchallenged, group occurred after nephrectomy but no comparable compensation in the infected group was found. Antibiotic therapy had a marked effect on the urinary concentrating capacity and the defect in concentrating ability was significantly less in the treated animals during the first 30 days after challenge. Infection again prevented a compensatory increase in the GFR of pyelonephritic animals which was not reversed by antibiotic therapy. Blood urea concentrations in treated and nontreated animals were not significantly different nor did the eradication of infection affect the gross pathologic and histopathologic changes found at autopsy.

Animals↗
PubMedDate not supplied

Increased affinity and preference of halogenated derivatives of BE 2254 for alpha 1-adrenoceptors demonstrated by functional and binding experiments.

The effects of congeners of BE 2254 (2-[beta-(4'-hydroxyphenyl)-ethyl-aminomethyl]-tetralone), an alpha 1-adrenoceptor antagonist, were compared in functional and binding experiments. In detail, we studied the effects of the compounds on the electrically evoked 3H overflow (alpha 2-adrenoceptor-mediated) and on the evoked contractions (alpha 1-adrenoceptor-mediated) of strips from rabbit pulmonary artery preincubated with [3H]noradrenaline as well as their effects on [3H]yohimbine binding to human platelet membranes (alpha 2-adrenoceptors) and [3H]prazosin binding to rat liver plasma membranes (alpha 1-adrenoceptors). The potencies of the drugs at the presynaptic alpha 2-adrenoceptors of the rabbit pulmonary artery and their affinities for [3H]yohimbine binding sites of human platelets were closely correlated. The same held true for their potencies at the postsynaptic alpha 1-adrenoceptors of the rabbit pulmonary artery and their affinities for [3H]prazosin binding sites of rat hepatic membranes. Compared with the parent compound, the monohalogenated derivatives of BE 2254 (i.e., the 3'-I, 3'-Br, and 3'-Cl analogues) exhibited an even higher affinity (equal to that of prazosin) and a higher selectivity for alpha 1-adrenoceptors (inferior to that of prazosin, but similar to that of corynanthine).

Adrenergic alpha-Antagonists↗
PubMed1998

Bacterial live vaccines with graded level of attenuation achieved by antibiotic resistance mutations: transduction experiments on the functional unit of resistance, attenuation and further accompanying markers.

At least 10% of spontaneous chromosomal antibiotic resistant mutants of bacteria express a strain-dependent graded reduction of virulence; this correlates linearly with a prolonged generation time. Occasionally, these mutants are temperature sensitive or/and auxotrophe. The work described in this paper provides evidence that in such strains the resistance and the accompanying markers exist only as a functional genetic unit. In a series of transduction experiments with a pathogenic strain of Salmonella typhimurium, it was found that without exception, the resistance and the additional markers were 100% simultaneoulsy transferred. Furthermore, antibiotic-resistant Escherichia coli mutants with prolonged generation time, were isolated from faecal samples; it is thus indicated that, such innocuous mutants occur at any time in the intestine. It is concluded that concerns connecting such mutants to the possibility of resistance dissemination are unfounded; furthermore, even if transfer of resistance occurred, only attenuated strains would be disseminated.

Animals↗
PubMed1998

Quantitative analysis of yeast gene function using competition experiments in continuous culture.

One possible route to the evaluation of gene function is a quantitative approach based on the concepts of metabolic control analysis (MCA). An important first step in such an analysis is to determine the effect of deleting individual genes on the growth rate (or fitness) of S. cerevisiae. Since the specific growth-rate effects of most genes are likely to be small, we employed competition experiments in chemostat culture to measure the proportion of deletion mutants relative to that of a standard strain by using a quantitative PCR method. In this paper, we show that both densitometry and GeneScan analysis can be used with similar accuracy and reproducibility to determine the proportions of (at least) two strains simultaneously, in the range 10-90% of the total cell population. Furthermore, we report on a model competition experiment between two diploid nuclear petite mutants, homozygous for deletions in the cox5a or pet191 genes, and the standard strain (ho::kanMX4/ho::kanMX4) in chemostat cultures under six different physiological conditions. The results indicate that competition experiments is continuous culture are a suitable method to distinguish quantitatively between deletion mutants that qualitatively exhibit the same phenotype.

Culture Media↗
PubMed2005

Glabrous dermal grafting: a 12-year experience with the functional and aesthetic restoration of palmar and plantar skin defects.

BACKGROUND: Glabrous skin on the palmar aspect of the hands and the plantar aspect of the feet has special attributes. These attributes define the skin on the palm, fingers, and sole as functionally and aesthetically different from skin on other parts of the body. When there is a glabrous skin defect, it should be replaced with similar skin to restore function and aesthetics. The authors report their 12-year experience with the technique of glabrous dermal grafting for the reconstruction of palmar and plantar skin defects. METHODS: From 1992 to 2004, 13 patients with 14 defects underwent glabrous dermal grafting of either palmar or plantar defects. Defects included nine hand and five foot defects. Causes included nine acute burns, one secondary burn reconstruction, two delayed reconstructions of traumatic injuries, one congenital nevus, and one malignant melanoma. Donor sites included 12 glabrous dermal grafts from the foot and two from the hand. RESULTS: Follow-up ranged from 1 month to 65 months. All glabrous dermal grafts demonstrated complete epithelialization and no incidence of complete loss. There was return of sensation without hyperkeratosis or breakdown. The grafts demonstrated good color match with the surrounding skin. The donor site healed without complications, and there were no incidences of significant hypopigmentation, hyperpigmentation, or hypertrophic scarring. CONCLUSION: Glabrous dermal grafting of palmar and plantar defects is the ideal way of reconstructing glabrous skin to restore both function and aesthetics and minimize donor-site morbidity.

Adolescent↗
PubMed1982

Nonparametric joint estimators for disease resistance and survival functions in survival/sacrifice experiments.

The nonparametric estimators proposed in this paper simultaneously estimate the disease resistance function, S(t), for the distribution of time to occurrence of disease, and the survival function, P(t), for the distribution of time to death caused by the disease. The estimators are applicable to animal survival data when the disease of interest is irreversible and the cause of death of each animal can be determined. Diseases need not be classified as universally lethal or universally nonlethal, and time to occurrence of the disease of interest need not be observable directly. It is shown that the proposed estimators are maximum likelihood estimators under the condition that S(t)/P(t) is monotonically decreasing. Application of the derived estimators is illustrated with experimental survival/sacrifice data, and results of a simulation study of the estimators' performance are reported.

Animals↗
PubMed1984

Relations of smoking and diving experience to pulmonary function among U.S. Navy divers.

The relations of 4 pulmonary function parameters (measured from the forced expiratory spirogram) with diving experience (in years) and indices of cigarette smoking were examined in a group of 93 healthy U.S. Navy divers. Years of diving was not significantly related to lung function. The value for pack-years of smoking was inversely associated with both percentage of predicted forced expiratory volume in 1 s (FEV1) and percentage of predicted maximal midexpiratory flow rate (MMFR). Divers who have relatively heavy smoking histories may be at greater risk for developing significant decline in pulmonary function, and diving exposure factors other than years of diving may contribute to this risk.

Adult↗
PubMed2005

Study of stem cell function using microarray experiments.

DNA Microarrays are used to simultaneously measure the levels of thousands of mRNAs in a sample. We illustrate here that a collection of such measurements in different cell types and states is a sound source of functional predictions, provided the microarray experiments are analogous and the cell samples are appropriately diverse. We have used this approach to study stem cells, whose identity and mechanisms of control are not well understood, generating Affymetrix microarray data from more than 200 samples, including stem cells and their derivatives, from human and mouse. The data can be accessed online (StemBase; http://www.scgp.ca:8080/StemBase/).

Animals↗
PubMed2007

Racism experiences and psychological functioning in African American college freshmen: is racial socialization a buffer?

Previous research has documented the negative effects of racism on the psychological health of African Americans. However, consideration of racial socialization as a potential buffer against racism experiences has received limited attention. The present study investigated whether two types of parental racial socialization messages reduced the impact of racism on psychological functioning in a sample of 247 African American college freshmen (M=18.30). Results indicated that students who reported more racism experiences also had poorer levels of psychological functioning as indicated by higher levels of psychological stress and psychological distress. Parental messages emphasizing the use of African American cultural resources to cope with racism reduced the impact of racism on psychological stress only. Cultural pride messages predicted less psychological distress while messages emphasizing the use of cultural resources predicted greater psychological distress. However, neither message type moderated the relationship between racism experiences and psychological distress. These results suggest that racial socialization messages have complex relations to psychological functioning in African American college students.

Adaptation, Psychological↗
PubMed2002

Hemodialysis patients' symptom experiences: effects on physical and mental functioning.

Dialysis patients experience numerous symptoms, some serious in terms of medical outcomes and all serious in terms of potential reductions in functioning and well-being. This cross-sectional study used self-reports of hemodialysis patients to catalogue symptoms; hypothesizing that frequently experienced symptoms, regardless of acuity, negatively affect functioning and well-being. Data were collected from 307 randomly selected hemodialysis patients from 14 dialysis facilities. Twenty-two of the 47 symptoms queried had mean experience scores of > or = 1 on a scale of 0-4, that is, were experienced by patients at least "a little of the time." Seventeen of these 22 symptoms were significantly correlated (< or = .01) with the SF-36 Physical Component Summary (PCS) scale, Mental Component Summary (MCS) scale, or both. All but four of these 17 symptoms (dry mouth, itchy skin, lack of appetite, and restless legs) clustered around fatigue/sleep, sexual concerns, or mobility. Linear multiple regression showed age, diabetes, the fatigue/sleep and mobility clusters, and itchy skin to be negatively associated with the PCS (p < or = .01). The fatigue/sleep cluster was also negatively associated with the MCS. Because previous research has shown the PCS and MCS to be associated with morbidity and mortality, management of common, non-acute symptoms may have long-term benefits for hemodialysis patients.

Activities of Daily Living↗
PubMedDate not supplied

[Model representation of rat motor behavior during electric self stimulation of the brain. II. Concretization of function shape. Comparison with experiment].

In this chapter the function of activity of the motor behavior in selfstimulation situation and function of the stimulation of the brain are determined. Solutions of the equation give the relation between the motor behavior and parameters of stimulation. The solutions agree with many experimental data in selfstimulation situation in the Skinner's box.

Animals↗
PubMedDate not supplied

Percutaneous renal artery embolisation of non-functioning allograft. Preliminary experience.

PURPOSE: Percutaneous renal artery embolisation has been introduced as an alternative to nephrectomy in patients with non-functioning allograft and Graft Intolerance Syndrome (GIS). The symptoms resulting from GIS include fever, local pain, hypertension and haematuria. MATERIALS AND METHODS: From April to October 2003, five patients were treated using this technique. The intraparenchymal renal arteries were embolized by injection of calibrated tris-acryl gelatin microspheres of increasing size (from 100-300 to 700-900 microns) and occlusion was completed by the insertion of 5mm to 8mm steel coils into the renal artery. RESULTS: The procedure was well tolerated in all cases and no major complications occurred. In 3 patients GIS-related symptoms disappeared immediately. One patient required a second embolisation due to collateral circulation arising from a lumbar artery with resolution of symptoms. In the last case, the patient underwent nephrectomy because of septic fever. CONCLUSIONS: On the basis of our preliminary experience we believe that, in selected patients, percutaneous renal artery embolisation is an effective, repeatable and minimally invasive alternative to nephrectomy with no significant serious complications.

Embolization, Therapeutic↗
PubMed1999

Problem solving and functional design features: experiments on cotton-top tamarins, Saguinus oedipus oedipus.

In any problem-solving situation, there are features associated with the problem that are relevant from a functional perspective and other features that are irrelevant. To determine whether animals are sensitive to the distinction between functionally relevant and irrelvant features of a problem, we conducted two main experiments with a New World monkey, the cotton-top tamarin. In the first condition of both experiments, subjects were required to pull a piece of cloth to gain access to a piece of food. The first experiment involved choosing between food that was on the cloth and food that was off the cloth. The second experiment involved choosing between food that was on a connected piece of cloth and food that was on two pieces of cloth separated by a horizontal gap. Having learned to solve either of these two problems, we conducted a series of probe conditions to determine whether the tamarins would generalize to changes in the shape, size, colour, and texture of the cloth and food, the position of the food relative to the cloth, and the type of connection between two pieces of cloth. For most of the probe conditions, the tamarins readily generalized, showing no decrement in performance, even on the first trial. For other conditions, involving apparently more subtle discrimination (e.g. a narrow vertical gap between the two pieces of cloth), explicit training was required. These results indicate that tamarins solve means-end relationships, and that their ability depends on a discrimination between properties that are functionally relevant as opposed to irrelevant. Copyright 1999 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1987

[Our experience in esthetic and functional surgery of the nose].

The authors report their experiences on functional and aesthetic nose surgery. The patients selection, the pre-operating test are based both on the rhinologic functionality and the photografic studies. Operative techniques are described together with pictures of most important stages. Results are shown with patients pictures before and after intervention.

Esthetics↗
PubMed1999

Influence of negative childhood experiences on psychological functioning, social support, and parenting for mothers recovering from addiction.

OBJECTIVE: This study was conducted with mothers recovering from drug and alcohol addiction and had three aims: first, to understand the range of negative childhood events these mothers experienced; second, to understand their current level of distress and their parenting experiences; and third, to examine the relationships between negative childhood events and parenting experiences. METHOD: Forty-six mothers participated in a cross-sectional exploratory study and completed a range of self-report measures, including the Child Abuse & Trauma Scale, Social Support Inventory, CES-D, Parenting Stress Index, and the Parenting Scale. RESULTS: When compared to norming samples these mothers reported significantly higher levels of aversive childhood experiences, psychological distress, parenting stress and use of problematic parenting behaviors along with lower levels of social support. Higher levels of neglect and growing up in a negative home environment were significantly correlated with lower levels of social support from the family, higher levels of distress and parenting stress, and greater use of problematic parenting behaviors. CONCLUSION: For this sample there is a greater incidence of aversive childhood experiences and greater problems with maternal functioning. Mothers recovering from addiction have an additional need for clinical attention towards issues of recovery from childhood abuse and responding to parenting difficulties with their own children.

Adult↗
PubMed1999

Driving experience and the functional field of view.

Research has suggested that novice drivers have different search strategies compared with their more experienced counterparts, and that this may contribute to their increased accident liability. One issue of concern is whether experienced drivers have a wider field of peripheral vision than less experienced drivers. This study attempted to distinguish between people of varying driving experience on the basis of their functional fields of view. Participants searched video clips taken from a moving driver's perspective for potential hazards while responding to peripheral target lights. Hit rates for peripheral targets decreased for all participant groups as processing demands increased (i.e. when hazards occurred) and as the eccentricity of the target increased, though there was no interaction. An effect of experience was also found which suggests that this paradigm measures a perceptual skill or strategy that develops with driving experience.

Accidents, Traffic↗