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At least 19 recordsLinked to original sources
PubMed2002

Reliability of an exercise protocol designed to evaluate resistance exercise performance.

The purpose of the present investigation was to evaluate the reliability a protocol used to assess short-term resistance exercise performance. Six men participated in this investigation after giving their consent. Subjects (N = 6) performed 6 sets of leg extensions at 80% of 10 repetition maximum (RM). Ten repetitions were performed during the first 3 sets; during the last 3 sets subjects exercised to fatigue. Ninety seconds of seated passive recovery separated each set. Subsequently, 2 experimental trials were conducted in which the exercise protocol was identical to the familiarization trial. There was a significant decline in performance from set 4 (13.5 +/- 0.9 reps) to set 5 (11.9 +/- 0.8 reps) and set 4 to set 6 (10.8 +/- 1.0 reps), suggesting that the protocol did induce fatigue. The intraclass correlations were 0.992, 0.992, and 0.993 for the fourth, fifth, and sixth sets, respectively. The average coefficients of variation for the fourth, fifth, and sixth sets were 6.7, 2.7, and 7.1%, respectively. These data suggest that the resistance training protocol used in this investigation is reliable and may be useful in evaluating interventions designed to improve fatigue resistance.

Adult↗
PubMed1993

[Incidence of the form and caliber of urethral resistance. Evaluation for a normal masculine urethra and in cases of obstruction due to prostatic hypertrophy].

Certain forms of benign prostatic hypertrophy are associated with a reduction of the calibre of the prostatic urethra of the median lobe, a defect of infundibulisation of the bladder neck and a dilated appearance of the bulbar urethra. The objective of this study was to verify whether hydrodynamic arguments could be used to confirm the concept that defective infundibulisation of the bladder neck is directly responsible for an obstructive syndrome or via a reduction in the calibre of the bladder neck orifice. More generally, this study was designed to quantify the distribution of resistance to flow along the normal urethra and to define the role of cervicoprostatic and urethral deformities in the obstruction associated with benign prostatic hypertrophy. Urodynamic studies are unable to answer this question, as the instantaneous urethral resistance is evaluated globally by the Pressure-Flow relation. The authors performed morphological analysis to divide the urethra into simple hydraulic segments for which the corresponding pressure drop coefficients were calculated. These coefficients constitute an approach to segmental resistance to flow and can be used to quantify changes in shape observed on voiding urethrography or ultrasonography. Digital analysis of voiding urethrographies showed that, under normal conditions, urethral resistance was regularly distributed along the urethra and essentially depended on friction of the urethral wall. In the case of benign prostatic hypertrophy, even with a median lobe, the increase in the pressure drop coefficients was due to a reduction in the calibre of the bladder neck orifice and prostatic urethra. Cervical deformities appeared to be minimally obstructive, according to urodynamic parameters, if they were not associated with a reduction in the calibre of the bladder neck orifice.

Evaluation Studies as Topic↗
PubMed1986

Mucociliary function and nasal resistance evaluation before and after adenoidectomy.

Thirty-four children with clinically and radiologically confirmed adenoid hypertrophy underwent otoscopy, impedance tests, active anterior rhinomanometry and nasal mucociliary clearance evaluation before and 6 months after adenoidectomy. Mucociliary clearance velocity increased significantly while binasal resistances decreased after surgery. The authors conclude that mucociliary evaluation and objective measurements of nasal resistances should be added to impedance tests as indicators to adenoidectomy.

Adenoidectomy↗
PubMed1996

Multidrug resistance evaluation by confocal microscopy in primary urothelial cancer explant colonies.

Assessing functional multidrug resistance (MDR) status in clinical biopsy material using drug autofluorescence has potential applications to clinical management. The small size of many cystoscopy specimens has led us to develop, as an alternative to flow cytometry, a protocol for studying epirubicin accumulation in adherent colonies of primary bladder cancer cells viewed live and in situ by confocal microscopy. The limitations to quantitation inherent in this technique are compensated for by preservation of cellular organisation and the elimination of non-malignant cells. Biopsy material is disaggregated and explanted into culture-grade petri dishes. After incubation for three to seven days plaques of epithelial cells have developed. Classical patterns of sensitive and resistant drug distribution are observed. Cells of the rolled edges of the colony accumulate more drug than those of the inner epithelial monolayer. Some central areas of larger colonies give the appearance of drug arrested at the intercellular junctions to give a fenestrated pattern. These observations contribute to the understanding of mechanisms in MDR as well as forming the basis for a clinical urological MDR evaluation protocol.

Antibiotics, Antineoplastic↗
PubMed2001

Highly reliable heterologous system for evaluating resistance of clinical herpes simplex virus isolates to nucleoside analogues.

Clinical resistance of herpes simplex virus (HSV) types 1 and 2 to acyclovir (ACV) is usually caused by the presence of point mutations within the coding region of the viral thymidine kinase (TK) gene. The distinction between viral TK mutations involved in ACV resistance or part of viral polymorphism can be difficult to evaluate with current methodologies based on transfection and homologous recombination. We have developed and validated a new heterologous system based on the expression of the viral TK gene by the protozoan parasite Leishmania, normally devoid of TK activity. The viral TK genes from 5 ACV-susceptible and 13 ACV-resistant clinical HSV isolates and from the reference strains MS2 (type 2) and KOS (type 1) were transfected as part of an episomal expression vector in Leishmania. The susceptibility of TK-recombinant parasites to ganciclovir (GCV), a closely related nucleoside analogue, was evaluated by a simple measurement of the absorbance of Leishmania cultures grown in the presence of the drug. Expression of the TK gene from ACV-susceptible clinical isolates resulted in Leishmania susceptibility to GCV, whereas expression of a TK gene with frameshift mutations or nucleotide substitutions from ACV-resistant isolates gave rise to parasites with high levels of GCV resistance. The expression of the HSV TK gene in Leishmania provides an easy, reliable, and sensitive assay for evaluating HSV susceptibility to nucleoside analogues and for assessing the role of specific viral TK mutations.

Acyclovir↗
PubMed1995

The effect of a cerebral vasodilator, vinpocetine, on cerebral vascular resistance evaluated by the Doppler ultrasonic technique in patients with cerebrovascular diseases.

Changes in cerebral vascular resistance were examined in patients with cerebral circulatory diseases by the Doppler ultrasonic technique after administration of a cerebral vasodilator, vinpocetine, for two months. Continuous index (CI) and pulsatility index (PI) of the blood flow pattern in the internal carotid artery were used as objective parameters for changes in cerebral vascular resistance. 1. The CI and PI changed significantly after administration of the drug; ie, the CI increased while the PI decreased. 2. An inverse correlation was noted between the rate of change of the CI (delta CI) and that of the PI (delta PI). 3. The results suggest that measurement of the CI and PI by the Doppler ultrasonic technique is useful in investigating the effect of drugs on the cerebral circulation.

Aged↗
PubMed1990

Critical controlled test to evaluate resistance of field strains of Haemonchus contortus to thiophanate.

Following reports of suspected gastrointestinal strongylid nematode resistance to thiophanate in sheep and goats at Sokoine University of Agriculture (SUA), Tanzania, field strains of Haemonchus contortus, one from SUA and another from Kimamba, Tanzania, were selected for a critical controlled test to evaluate the efficacy of thiophanate. The SUA H. contortus strain in goats showed a marked resistance to thiophanate at an oral dose of 50 mg kg-1 liveweight (efficacy = 24.1%), while the Kimamba H. contortus strain showed very marked susceptibility (efficacy = 99.7%) to thiophanate at the same oral dose. This is the first report from East Africa of a field strain of H. contortus resistant to thiophanate. The incidence of resistant strains of strongyloid parasites to benzimidazole anthelmintics in sheep and goats in East Africa is on the increase. The magnitude of this problem should be evaluated and remedial solutions sought.

Abomasum↗
PubMed1995

Comparative study of multidrug resistance evaluated by means of the quantitative immunohistochemical detection of P-glycoprotein and the functional release of rhodamine 123.

The immunological detection of P-Glycoprotein (P-GP) and the functional release of Rhodamine 123 (R123) have been compared in a number of human and murine cancer cell lines, in chemo- and/or radiotherapy-resistant subclones, and in clinical specimens from patients. The chemoresistance level was established from the viability index (IC50) in the presence of doxorubicin. Cytocentrifuge preparations were immunostained with JSB-1 monoclonal antibody followed by the alkaline phosphatase anti-alkaline phosphatase technique. The strength of the reaction was quantified by a digital image analyser. The kinetic incorporation and release of Rhodamine 123 were evaluated by flow cytometry. The parent cell lines and radiotherapy resistant subclones showed a low IC50, were JSB-1 negative and retained R123 during the whole experiment, while the chemoresistant and radio-chemoresistant cell line mutants had a high IC50, were JSB-1 positive, and actively pumped the R123 out of the cells. Good correlations were obtained between the IC50, the digital image analysis, and flow cytometry. The kinetic profile of the R123 release allowed the distinction between typical and atypical multidrug resistance phenotypes. These findings were confirmed in clinical specimens from patients. We conclude that antigenic and functional studies are complementary and are useful in experimental and clinical approaches to multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Structure-activity and cross-resistance evaluations of a series of human immunodeficiency virus type-1-specific compounds related to oxathiin carboxanilide.

A series of compounds related to the nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) oxathiin carboxanilide (UC84) were evaluated for activity against the human immunodeficiency virus (HIV) to determine structural requirements for anti-HIV activity. Twenty-seven compounds representative of the more than 400 Uniroyal Chemical Company (UC) compounds were evaluated for structure-activity relationships. Several of the compounds evaluated were highly active, with 50% effective concentrations in the nanomolar range and therapeutic indices of > 1,000. Highly synergistic anti-HIV activity was observed for each compound when used in combination with 3'-azido-3'-deoxythymidine; additive to slightly synergistic interactions were observed with the compounds used in combination with dideoxycytidine. In combination with the NNRTI costatolide, only UC38 synergistically inhibited HIV type 1. Residues in the RT which, when mutated, impart resistance to the virus isolates selected in cell culture, against virus variants with site-directed mutations, and against RTs containing defined single amino acid changes. The mutations included changes in RT amino acids 100, 101, 103, 106, 108, and 181. The results with isolates selected in cell culture indicate that the carboxanilide compounds interact with the RT at two vulnerable sites, selecting UC-resistant virus isolates with the Y-to-C mutation at position 181 (Y181C) or the L100I substitution. A resistant virus isolate containing both Y181C combination with calanolide A, an NNRTI which retains activity against virus with the single Y181C mutation, UC10 rapidly selected a virus isolate with the K103N mutation. The merits of selecting potential candidate anti-HIV agents to be used in rational combination drugs design as part of an armamentarium of highly active anti-HIV compounds are discussed.

Antiviral Agents↗
PubMed1994

[Dopamine-induced variations in intrarenal resistance. Evaluation with Doppler ultrasound].

Low-dose dopamine is commonly used for the management of acute renal failure because of its exclusively renal vasodilator effect which is mediated through two specific receptors. However, the experimental background of this role is controversial in man. Indeed, the available data come mainly from animal trials and uncontrolled studies in patients with left ventricular dysfunction who need other drugs to improve cardiac output. This work was aimed at investigating Doppler value in assessing the effects of low-dose dopamine infusion in healthy subjects. Heart rate, arterial blood pressure and RI were measured before, during (at 10, 20 and 30 minutes) and after low-dose dopamine infusion in 4 healthy volunteers. In all subjects the RI reduced significantly, returning to the initial values after drug infusion. Indeed, the average RI (0.648 +/- 0.015 before drug administration) decreased to 0.595 +/- 0.026 within 10 min of infusion and remained almost the same during the infusion (0.596 +/- 0.024 within 20 min of infusion, 0.585 +/- 0.032 within 30 min). Within 10 min of the end of infusion, the average RI returned to similar values to those measured before drug administration (0.643 +/- 0.02). Changes in heart rate and arterial blood pressure were not significant. Our results confirm the vasodilator role of low-dose dopamine to be free of systemic effects in healthy volunteers with no therapeutic support which would cause extrarenal decrease in peripheral vascular resistance.

Adult↗
PubMed1995

[Study on insulin resistance evaluated by glucose tolerance test in obese pregnant women].

This study examined the plasma glucose level and immunoreactive insulin (IRI) level in the course of 75g oral glucose tolerance test (OGTT) during pregnancy in 27 obese women (pre-pregnant body mass index (BMI) > = 24kg/m2) and 53 non-obese women (BMI < 24kg/m2). In women with normal glucose tolerance, the fasting IRI level, IRI area under a 3-h curve during 75gOGTT (IRI-AUC) and the net increase in IRI areas above fasting values under a 3-h curve (delta IRI-AUC) in 15 obese women were higher than those in 47 non-obese women (p < 0.01, p < 0.05, p < 0.03), but there was no difference between the two groups in the fasting plasma glucose level, BS-AUC or delta BS-AUC. In women with abnormal glucose tolerance, the fasting IRI level in 12 obese women was higher than that in 6 non-obese women (p < 0.01), but there were no significant differences in the other factors. The fasting IRI level was correlated with the fasting plasma glucose level, BS-AUC, IRI-AUC and BMI (p < 0.002, p < 0.001, p < 0.0001, p < 0.0001). These results show that there is a higher insulin level and lower systemic sensitivity to insulin in obese women than in non-obese women in all groups.

Adult↗