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Abstract
Between 1975 and 1987, 115 patients underwent inferior turbinectomy and 87% were available for review. The nature and extent of their pre- and postoperative symptoms were determined, and rhinoscopy was undertaken to establish the completeness of turbinectomy and the presence of intranasal complications. Of these patients, 88% reported improvements in nasal obstruction and 50 to 78% of the patients who had experienced other troublesome nasal symptoms reported improvements in these. Primary hemorrhage occurred in two patients and during the early postoperative months three patients experienced crusting, three had spotty bleeding, and one had discomfort caused by increased airway patency. On examination nine patients had mild asymptomatic crusting, seven had incompletely resected turbinates, and 12 had intranasal adhesions. None had atrophic rhinitis.
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Rigid endoscopy in globus pharyngeus: how valuable is it? The Journal of Laryngology & Otology 2005; 120:42-6. [PMID: 16359156 DOI: 10.1017/s0022215105006043] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/26/2005] [Indexed: 12/23/2022]
Abstract
The aim of this study was to assess the value of rigid endoscopy in patients presenting with globus symptoms. We conducted a retrospective analysis of 250 patients who underwent rigid endoscopy for globus symptoms over a 12-month period. In 217 patients (86.8 per cent) the examination of the larynx, pharynx and upper oesophagus was entirely normal. Abnormal findings included cricopharyngeal spasm in 12 patients (4.8 per cent), reflux in 11 (4.4 per cent), pharyngitis in two (0.8 per cent), web in two (0.8 per cent), and retention cyst in three (1.2 per cent). The 95 per cent confidence interval (CI) for the mean number of persons with malignancy based on the Poisson distribution is 0 and 3.7 (0 and 14.8 as rates per 1000). The relationship between the clinical diagnosis and endoscopic findings was examined using the chi-square test, with a p value of 0.0001. These results suggest that patients presenting with globus sensation are unlikely to harbour neoplastic lesions and therefore rigid endoscopy may well be an inappropriate investigation in this group. The risks, costs and discomfort associated with this intervention can often be avoided.
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Clinical evaluation of the electronic nose in the diagnosis of ear, nose and throat infection: a preliminary study. The Journal of Laryngology & Otology 2005; 118:706-9. [PMID: 15509368 DOI: 10.1258/0022215042244660] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The term electronic nose describes an electronic system that is able to mimic the human sense of smell. Electronic noses have been developed over the last 10 or more years to perform a variety of identification tasks in various industries. More recently electronic noses have attracted new interest in their application in the field of medical diagnosis. The aim of this study is to explore the use of an electronic nose to identify and classify pathogens associated with ear, nose and throat (ENT) infections. In this study 90 bacterial swab samples were collected from 90 patients with ENT infections. Some of these samples were analysed immediately with a commercial electronic nose (Cyranose C320). Similar numbers of swabs were also taken from the same site of infection and were sent for microbiology culture and sensitivity. The electronic nose diagnosis was compared with the microbiology diagnosis and it was found that the electronic nose diagnosis was correct in 88.2 per cent of the cases, which is an encouraging result.
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Interrelationships among thigh muscle co-contraction, quadriceps muscle strength and the aerobic demand of walking in children with cerebral palsy. ELECTROMYOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 2004; 44:103-10. [PMID: 15061404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The purpose of this study was to quantify interrelationships among thigh muscle co-contraction, quadriceps muscle strength, and the aerobic demand of walking in 13 children with spastic hemiplegic cerebral palsy (CP). During Session 1, subjects were familiarized with testing procedures, given five minutes of treadmill walking practice, and completed quadriceps muscle strength testing. In Session 2, subjects performed three 5-min walking bouts on the treadmill at 0.67 m x s(-1) to further accommodate to treadmill ambulation. During Session 3, resting VO2 was measured and subjects walked at 0.67, 0.89, and 1.12 m x s(-1) for five minutes while oxygen uptake (VO2) and thigh muscle co-contraction data were collected. Results demonstrated that no significant relationship existed between net VO2 and measures of thigh muscle co-contraction or quadriceps muscle strength. In addition, thigh muscle co-contraction was not shown to be associated with quadriceps muscle strength. Collectively, thigh muscle co-contraction and quadriceps muscle strength explained 13. 5%, 6.2%, and 2.2% of the variance in VO2 at 0.67, 0.89, and 1.12 m x s(-1), respectively. Viewed in concert, these results suggest that the walking energy expenditure of children with spastic hemiplegic CP is not influenced by the level of thigh muscle co-contraction or quadriceps muscle strength.
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Abstract
Matrix metalloproteinases (MMPs) and cyclooxygenase-2 (COX-2) are expressed in both sporadic and familial adenomatous colonic polyps and tumours and have been independently shown to play causal roles in intestinal tumour formation in mouse models of colon cancer. The apparent roles of these enzymes in intestinal tumorigenesis led us to examine, in the Min mouse model of colon cancer, if selective COX-2 and MMP inhibitors provide additive or synergistic therapeutic benefits in intestinal tumour prevention. The broad-spectrum MMP inhibitor (A-177430; MMPI) and the selective COX-2 inhibitor (A-285969; COX-2I) both showed dose-dependent inhibition of the number of adenomas in Min mice. Using suboptimal doses, the MMPI reduced tumour multiplicity by 32%, the COX-2I by 48% and, both agents in combination resulted in a 67% decrease compared to control demonstrating a cooperative effect on intestinal tumorigenesis. Apoptosis, proliferation, and angiogenesis were assayed in tumors from each treatment group. These agents in combination allowed for a lowered dosage to be administered to achieve significant biological effects. Clinically, this could potentially reduce side effects associated with currently used MMP and COX-2 inhibitors. Together, these compounds could represent an easily tolerated chemopreventive approach.
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Abstract
Snoring is a significant problem with both social and medical manifestations. This article addresses the current management of the simple snorer from initial out-patient assessment to definitive treatment.
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Abstract
It is common to see cholesterol granuloma in the mastoid air cells, less common in the orbit, and uncommon in the paranasal sinuses. Cholesterol granuloma is thought to be due to an interruption to normal aeration with impaired lymphatic drainage, resulting in a closed cavity where it may form. These expanding cysts cause bone destruction and compression of the surrounding structures that lead to clinical symptoms. Diagnosis and management of cholesterol granuloma cysts can be challenging. Magnetic resonance imaging (MRI) and computed tomographic (CT) scans are usually diagnostic. We present a rare case of cholesterol granuloma in the frontal sinus, few cases have been reported in the literature.
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Abstract
The aim of this study was to retrospectively survey patients who had undergone radiofrequency ablation of the soft palate for snoring complaints. Fifty-nine patients who had undergone radiofrequency ablation were sent an anonymous questionnaire to assess snoring (using visual analogue scales), pain and satisfaction with the procedure. Sixty-one per cent of the group returned the questionnaire. The mean time since operation was 17.5 months. Taking an improvement in snoring of 50 per cent or greater as a successful operation, snoring improvement occurred in 22 per cent. Post-operative pain was minimal with a median pain score of zero. Information was requested on whether the patient would undergo this procedure again, 50 per cent responded that they would and 44 per cent would advise a friend in the same situation to have this procedure. Radiofrequency ablation of the soft palate, as in other forms of surgery for snoring, seems to have a relapse rate over the long-term.
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Intracochlea acoustic neuroma: a case report and discussion. Eur Arch Otorhinolaryngol 2001; 258:557-9. [PMID: 11829196 DOI: 10.1007/s004050100381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A case of an intracochlea acoustic neuroma that was diagnosed radiologically is presented and discussed.
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Abstract
Maffucci's syndrome is a rare congenital non-inherited condition, characterized by multiple enchondromata, cutaneous haemangiomata and more recently spindle-cell haemangioma-endotheliomata. It is associated with an increased risk of malignancy including intracranial chondrosarcomas. Early diagnosis is crucial; screening patients with Ollier's disease is recommended. The treatment of choice for these intracranial cartilaginous tumours is complete surgical excision but this is often difficult to achieve due to difficult access and relationships with neurovascular structures. An alternative treatment is proton-beam therapy. We report a case of Maffucci's syndrome; illustrating the typical clinical and radiological features as well as the known complications of the condition.
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11
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Occurrence and risk of cochleotoxicity in cystic fibrosis patients receiving repeated high-dose aminoglycoside therapy. Antimicrob Agents Chemother 2001; 45:2502-9. [PMID: 11502521 PMCID: PMC90684 DOI: 10.1128/aac.45.9.2502-2509.2001] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2000] [Accepted: 05/31/2001] [Indexed: 11/20/2022] Open
Abstract
Cystic fibrosis (CF) patients receive repeated courses of aminoglycoside therapy. These patients would consequently be expected to be more susceptible to cochleotoxicity, a recognized side effect with single courses of aminoglycoside therapy. The primary aim of this retrospective study was to establish the incidence and severity of auditory deficit in CF patients. Standard (0.25- to 8-kHz) and high-frequency (10- to 16-kHz) pure-tone audiometry was carried out in 70 CF patients, and the results were compared with the results from 91 control subjects. These subjects were further divided into pediatric and adult groups. Of 70 CF patients, 12 (1 pediatric) displayed hearing loss considered to be caused by repeated exposure to aminoglycosides. There was a nonlinear relationship between the courses of therapy received and the incidence of hearing loss. The severity of the loss did not appear to be related to the number of courses received. Assuming the risk of loss to be independent for each course, preliminary estimates of per course risk of hearing loss were less than 2%. Upon comparison with previous clinical studies and experimental work, these findings suggest that the incidence of cochleotoxicity in CF patients is considerably lower than would be expected, suggesting that the CF condition may confer protection against aminoglycoside cochleotoxicity.
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Discovery and characterization of the potent, selective and orally bioavailable MMP inhibitor ABT-770. Bioorg Med Chem Lett 2001; 11:1557-60. [PMID: 11412980 DOI: 10.1016/s0960-894x(01)00032-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Modification of the biphenyl portion of MMP inhibitor 2a gave analogue 2i which is greater than 1000-fold selective against MMP-2 versus MMP-1. The stereospecific synthesis of both enantiomers of 2i was achieved beginning with (S)- or (R)-benzyl glycidyl ether. The (S)-enantiomer, 11 (ABT-770), is orally bioavailable and efficacious in an in vivo model of tumor growth.
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13
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Abstract
A novel series of biaryl ether reverse hydroxamate MMP inhibitors has been developed. These compounds are potent MMP-2 inhibitors with limited activity against MMP-1. Select members of this series exhibit excellent pharmacokinetic properties with long elimination half-lives (7 h) and high oral bioavailability (100%).
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14
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Abstract
The objective of this investigation was to determine the individual contributions of perceived daily, major, and total stressors to blood pressure in early adolescent children. Toward this goal, cardiovascular risk factors were assessed in 74 6th-grade students. Height and body weight, measured in standard fashion, were used to calculate body mass index (BMI). Waist and hip circumferences and triceps and calf skinfolds were taken to determine the distribution and percentage of body fat, respectively. Seated resting blood pressure was obtained using a mercury sphygmomanometer. The dietary sodium-to-potassium ratio was calculated from a food intake questionnaire. Family history of hypertension was self-reported by participant's parents, and physical activity and perceived stress levels were determined by questionnaire. When added to the hierarchical regression models, the perceived stress variables did not significantly predict any additional variance in systolic or diastolic blood pressure in this early adolescent sample. Additionally, bivariate correlations between the stress variables and blood pressure were nonsignificant. The nonpsychological hypertension risk factors accounted for 25%-35% of the total variance in systolic and diastolic blood pressure. Further, regression analyses revealed that with the exception of BMI and the sodium-to-potassium ratio, no other risk factors were independent predictors of systolic or diastolic blood pressure. Further identification and understanding of environmental precursors of childhood hypertension is recommended.
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Abstract
Few studies have been conducted documenting the length of time required for young children to achieve stable measures of running economy. Hence the purpose of this study was to quantify within- and between-day stability in running economy among young children. To address this issue, 30 6-year olds (16 girls, 14 boys) completed three test sessions within a 2 wk period. During Sessions 1 and 2 subjects performed three 5 min level treadmill runs at 2.23 m x sec(-1). During Session 2 expired air was collected during the last 2 min of each 5 min run (R1, R2, R3) and analyzed to determine VO2. In Session 3 subjects completed a single 5 min run (R4) at 2.23 m x sec(-1) and VO2 was measured during the last 2 min of running. Data analysis revealed no significant difference (p>0.05) in absolute or relative VO2 across trials. The average coefficient of variation for both absolute and relative VO2 among runs completed in Session 2 was 2.17 %, and the mean coefficient of variation for VO2 between R4 and the average VO2 of R1, R2, and R3 was 2.51 % and 2.35% for absolute and relative VO2, respectively. Moreover intraclass correlation coefficients for absolute and relative VO2 across all runs were 0.99 and 0.96, respectively. Viewed in concert, these results suggest that following 15 minutes of level treadmill running practice, stable within- and between-day measures of running economy can be obtained in young, prepubescent children.
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Audit of headache following resection of acoustic neuroma using three different techniques of suboccipital approach. REVUE DE LARYNGOLOGIE - OTOLOGIE - RHINOLOGIE 2000; 121:75-8. [PMID: 10997062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
A retrospective case notes review using pain visual analogue scale (VAS) and assessment of analgesia required by patients in the post-operative period at 1, 3, 6, 12 and over 12 months following acoustic neuroma resection was performed. Glasgow Benefit Inventory (GBI) score was used to assess the change of quality of life and its relationship to pain following surgery. Questionnaires of 71 patients were included in the study, 23 of whom underwent wide craniotomy including dissection of upper cervical musculature (CE), 25 wide craniotomy with replacement of bone flap (CO) and 23 minimally invasive, approximately 2 x 2 cm, minicraniectomy (MCE). The minicraniectomy resulted in significantly diminished pain from third month post surgery as compared with wide craniectomy (p < 0.05) and patients required less analgesia. Similarly, CO patients have experienced significantly less pain than CE patients (p < 0.05), but only after 12 months following surgery. Although consistently less in absolute visual analogue scores, there was no statistically significant difference between the amount of pain recorded by CO and MCE patients. There was no correlation between gender or age and the VAS pain score. The mean Glasgow Benefit Inventory score for all patients was -6.6, and there was no significant difference between operation types, genders or age. Although bone flap replacement appears to diminish the amount of post-operative pain, minimal invasive technique resulted in least pain following acoustic neuroma resection in our patients.
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Abstract
Few data exist concerning the reproducibility of stable oxygen uptake (VO(2)) values during level treadmill walking in young able-bodied children. To address this issue, 41 able-bodied 6-year-olds (19 boys, 22 girls, X height=117.2+/-4.7 cm, X body mass=21.8+/-2.5 kg) were tested on two occasions. In session 1, subjects were familiarized with the laboratory environment and performed 5 min of level treadmill walking at 1.34 m s(-1). During session 2, each child completed 30 min (three 10-min trials) of level treadmill walking at 1.34 m s(-1). For each 10-min trial, mean VO(2) was determined by averaging VO(2) values obtained from analysis of two 2-min expired gas samples. While the mean VO(2) for trial 1 was higher than values recorded for trials 2 and 3, effect sizes corresponding to these differences were low (</=0.16). Average within subject coefficient of variation and intraclass reliability coefficient values for VO(2) across the three walking trials were 2. 0+/-1.5% and 0.96, respectively. Viewed collectively, these results suggests that among young able-bodied children, acceptably and reproducible stable VO(2) values during level treadmill walking can be obtained within 10 min if data collection is preceded by exposure to testing procedures and a brief period of treadmill walking practice.
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Synthetic inhibitor of matrix metalloproteases decreases tumor growth and metastases in a syngeneic model of rat prostate cancer in vivo. Int J Cancer 2000; 87:276-82. [PMID: 10861487 DOI: 10.1002/1097-0215(20000715)87:2<276::aid-ijc20>3.0.co;2-l] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Members of the matrix metalloprotease (MMP) family are implicated in the progression of several malignancies including prostate cancer due to their ability to break down extracellular matrix (ECM) components. In this study, we have evaluated the ability of a synthetic MMP inhibitor (A-177430) to block tumor growth and metastases in a syngeneic model of rat prostate cancer. In an in vitro substrate assay, A-177430 exhibited nanomolar potency (IC(50) 2-6 nM) against the enzymatic activity of several MMPs. For in vivo studies, male Copenhagen rats were injected s.c. with Mat Ly Lu rat prostate cancer cells (1 x 10(6) cells ) into the right flank and animals were administered i.p.with different doses (10-100 mg/kg per day) of A-177430 for 16 days. Administration of A-177430 resulted in a dose-dependent decrease in tumor volume as compared to a control group of animals receiving vehicle alone. The maximum dose (100 mg/kg per day) of A-177430 exhibited complete arrest in tumor growth and prevented the development of macroscopic tumor metastases to lungs without exhibiting any noticeable side effects. Histologic examination of primary tumors from experimental animals showed extensive tumor necrosis and decreased tumor angiogenesis as determined by factor VIII staining of primary tumors following A-177430 treatment. These primary tumors from experimental animals also exhibited a significant increase in tumor cell DNA fragmentation as determined by TUNEL assay. Collectively, these results demonstrate the ability of MMP inhibitors to block tumor growth and metastases by blocking ECM degradation and by inhibiting tumor angiogenesis and promotion of prostate cancer cell apoptosis in vivo.
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Abstract
The case history is presented of a patient with acute respiratory failure complicated by nasal obstruction resulting in intolerance of nasal ventilation. Urgent insertion of nasal stents permitted restoration of ventilation with resolution of breathlessness and stabilisation of arterial blood gases.
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Abstract
Twenty-six adult cystic fibrosis patients were studied to compare nasal disease with their laboratory correlates including skin testing, immunoglobulin and Aspergillus fumigatus precipitin levels, saccharin testing and sputum cultures. Six patients were asymptomatic and all of these had negative skin tests, normal IgE levels and negative Aspergillus fumigatus precipitins. Thirteen patients had rhinitis, 12 had positive skin-testing for common allergens, 10 elevated IgE levels and nine positive Aspergillus fumigatus precipitins. Seven patients had polyps, all had normal IgE levels and negative Aspergillus fumigatus precipitins, six had positive skin testing for common allergens. There also appeared to be a relationship between Pseudomonas spp. colonization and positive skin testing.
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External acoustic meatus cholesteatoma. ORL J Otorhinolaryngol Relat Spec 1999; 61:158-60. [PMID: 10325556 DOI: 10.1159/000027662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cholesteatoma is a condition usually affecting the middle ear and mastoid, but in certain cases it can be found in the external ear canal. It usually affects elderly people and presents with chronic otorrhoea and dull otalgia. The disease can progress to extensive mastoid destruction. Small lesions can be treated with regular microscopic debridement in out-patients while larger lesions require surgery to eradicate the cholesteatoma sac. We present 2 cases of external ear cholesteatoma to add to the less than 50 cases reported to date.
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Extracellular matrix (ECM) mediated adhesion and signaling in inflammation and cancer: new concepts, New York Academy of Sciences, May 21, 1998. Inflamm Res 1999; 48:104-5. [PMID: 10219651 DOI: 10.1007/s000110050432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Enhancement of the surface expression of tumor necrosis factor alpha (TNFalpha) but not the p55 TNFalpha receptor in the THP-1 monocytic cell line by matrix metalloprotease inhibitors. Biochem Pharmacol 1999; 57:291-302. [PMID: 9890556 DOI: 10.1016/s0006-2952(98)00300-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The monocytic cell line THP-1 can be induced to express and release tumor necrosis factor alpha (TNFalpha) and both TNFalpha receptors (p55 and p75) upon exposure to bacterial lipopolysaccharide (LPS). The broad-spectrum matrix metalloprotease (MMP) inhibitors [4-(N-hydroxyamino)-2R-isobutyl-3S-(phenylthiomethyl)succinyl]-L-p henylalanine-N-methylamide (GI-129471) and marimastat [2S-[N4(R*),2R*,3S*]]-N4[2,2-dimethyl-1-[(methylamino)carbonyl]propyl]-N 1,2-dihydroxy-3-(2-methylpropyl)butanediamide (BB-2516) were effective inhibitors of LPS-induced TNFalpha (soluble) release with IC50 values of 0.2 and 4.0 microM, respectively. Upon LPS stimulation, the expression of pro-TNFalpha (membrane associated) on the cell surface (FACS analysis) could not be observed. However, in the presence of GI-129471, a concentration-dependent increase in TNFalpha surface expression was observed. Peak expression (percentage of cells expressing pro-TNFalpha and mean fluorescence units) in the presence of GI-129471 was at 2 hr, and steadily declined to return to near control levels by 8 hr. This time course was similar to TNFalpha release, which also peaked at 2-4 hr after LPS exposure and then declined. Stimulation of THP-1 cells with LPS + phorbol myristate acetate increased the percentage of cells expressing pro-TNFalpha by 10-fold. In the presence of GI-129471, these increases were augmented further and peaked between 2 and 4 hr, but also returned to near control levels of expression by 24 hr. This was in contrast to the release of soluble TNFalpha, which continued to accumulate over a 24-hr time course. TNFalpha receptor I (p55, TNFRI) and II (p75, TNFRII) shedding was also inhibited by GI-129471 (IC50 = 1.5 and 3.1 microM, respectively) and BB-2516 (IC50 = 14 and 15 microM, respectively). Unlike pro-TNFalpha surface expression, surface expression of both TNFalpha receptors steadily increased over 72 hr. In contrast to pro-TNFalpha surface expression, TNFRI surface expression was not augmented by these MMP inhibitors in THP-1 cells after LPS stimulation. Surface expression of TNFRII was augmented by these MMP inhibitors. These results suggest that even in the continued presence of LPS stimulation and an inhibitor of TNFalpha processing, the augmented surface expression of TNFalpha is transient. The potential "deleterious" implications of high levels of surface pro-TNFalpha expression in the presence of these inhibitors may be lessened by its transient nature.
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Aryl ketones as novel replacements for the C-terminal amide bond of succinyl hydroxamate MMP inhibitors. Bioorg Med Chem Lett 1998; 8:3251-6. [PMID: 9873712 DOI: 10.1016/s0960-894x(98)00597-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of succinyl hydroxamate MMP inhibitors were prepared incorporating an aryl amino ketone moiety in place of the more typical C-terminal amino acid amides. Compounds of the C-terminal ketone series displayed potent inhibition of MMPs. Several compounds of the series were shown to be orally bioavailable.
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Relationship between 800-m running performance and accumulated oxygen deficit in middle-distance runners. Med Sci Sports Exerc 1998; 30:1631-6. [PMID: 9813877 DOI: 10.1097/00005768-199811000-00012] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To determine whether there is a significant relationship between accumulated oxygen deficit (AOD) and 800-m running performance in a group of runners of homogeneous ability. METHODS Nine well-trained male middle and long distance runners (age = 24.7 +/- 4.5 yr, body mass = 69.4 +/- 8.5 kg, VO2max = 64.8 +/- 4.5 mL.kg-1.min-1) underwent treadmill testing to determine maximum oxygen uptake (VO2max), running economy (RE) at 1% and 10.5% treadmill gradient, and AOD at 1% and 10.5% treadmill gradient; 800-m running performance was determined by time trials on an outdoor 440-yd track, for which the average time was 132 +/- 4 s. For the AOD test, subjects were required to run on the treadmill at supramaximal speeds until volitional exhaustion. The AOD value was calculated using linear (LIN) and curvilinear (CUR) extrapolation procedures. RESULTS Mean AOD values using LIN and CUR were 45.0 +/- 6.9 and 59.3 +/- 10.1 mL.kg-1 at a 1% treadmill gradient and 63.2 +/- 10.6 and 93.6 +/- 19.7 mL.kg-1 at a 10.5% gradient, respectively. No significant relationship was found between 800-m run time and AOD at 1% gradient or 10.5% gradient or when AOD was estimated from a linear or curvilinear fit of the VO2 data. Other variables measured in this study (e.g., VO2max and running economy) were not found to be predictive of 800-m run time. CONCLUSION Among a homogeneous group of well-trained male middle- and long-distance runners, AOD measured at a 1% and 10.5% treadmill gradient is not significantly related to 800-m running performance.
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The design, synthesis, and structure-activity relationships of a series of macrocyclic MMP inhibitors. Bioorg Med Chem Lett 1998; 8:2087-92. [PMID: 9873491 DOI: 10.1016/s0960-894x(98)00396-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of succinate-derived hydroxamic acids incorporating a macrocyclic ring were designed, synthesized, and evaluated as inhibitors of matrix metalloproteinases. The inhibitors were designed based on the published X-ray crystal structure of batimastat (1) complexed with human neutrophil collagenase (MMP-8). The synthesized compounds were shown to inhibit selected MMPs in vitro with low nanomolar potency.
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Abstract
BACKGROUND This study examined the association between blood pressure (BP), selected health behaviors, and various dimensions of religiosity among females. METHODS Data were obtained on 112 females who were at least 35 years of age and of Judeo-Christian faith. Resting BP measures were taken with an automated sphygmomanometer, height and weight were measured to determine body mass index (BMI), and intermediate health variables (e.g., physical activity, smoking, diet, and alcohol consumption) were measured by questionnaire. A multifactorial questionnaire was used to assess various dimensions of religiosity. Multiple regression path analyses were conducted to determine the direct and indirect effects of religiosity on BP with age and BMI controlled statistically. RESULTS The direct effects of religiosity on SBP and DBP were more substantial than the indirect effects through the intermediate health variables, suggesting that religiosity may be associated with lower levels of BP via a direct pathway, such as improving the ability to cope with stress. In general, DBP was more influenced by religiosity than SBP and the dimensions of "intrinsic religiosity" and "religious coping" were most influential. Results also indicated that "religious experiences" may exert a greater beneficial effect on DBP in older (50-80 years) age groups. CONCLUSIONS These results support a direct relationship between religiosity and BP, rather than an indirect effect through intermediate health behaviors.
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Abstract
It has been reported that adults suffering from refractory essential hypertension experience significantly fewer positive life events than healthy peers. However, the influence of positive life events on blood pressure (BP) in adolescents has been largely ignored. Therefore, we examined the relationship between self-reported positive life events and BP in 69 sixth graders with a mean age of 11.7 years. Positive life events were assessed with the Adolescent Perceived Events Scale and resting blood pressure was measured with a mercurial sphygmomanometer. Correlational analyses showed an inverse relationship between positive life events and diastolic BP, suggesting that adolescents experiencing more positive life events were more likely to have lower diastolic BP's. Hierarchical regression analyses revealed that physical activity level, dietary sodium-to-potassium ratio, parental history of hypertension, and measures of body composition predicted 24.6% of the variance in systolic BP and 34.6% of the variance in diastolic BP. Moreover, positive life events predicted an additional 4.3% of the variance in diastolic BP when statistically controlling these established risk factors for hypertension. These results suggest that increased perceptions of positive life events may act as a buffer to elevated BP in adolescents.
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B-cell lymphoma with extensive cutaneous involvement presenting to the ENT surgeon. J Laryngol Otol 1998; 112:186-8. [PMID: 9578884 DOI: 10.1017/s0022215100140277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AbstractThis paper reports an unusual case of B-cell non-Hodgkin's lymphoma presenting with extensive cutaneous involvement of the head and neck region.
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Capital versus noncapital murderers. THE JOURNAL OF THE AMERICAN ACADEMY OF PSYCHIATRY AND THE LAW 1998; 26:403-410. [PMID: 9785284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This study compares three groups of murderers: those who have received a death sentence (n = 18), those who were eligible to receive a death sentence but did not have it sought against them (n = 18), and those who were not eligible for the death penalty (n = 18). A retrospective record review of these 54 pretrial detainees in South Carolina who underwent court-ordered competency and criminal responsibility evaluations was completed comparing the following variables: age, race, marital status, educational level, prior legal history, relationship to the victim, race of the victim, existence of a codefendant, prior psychiatric history, psychiatric diagnoses, substance abuse history, use of substances at the time of the crime, Wechsler Adult Intelligence Scale (WAIS) or WAIS-Revised Full Scale IQ, and evidence of organic impairment. Statistically significant findings included race of the murderer, race of the victim, relationship to the victim, and existence of a codefendant. Death row inmates were more likely to be Caucasian and much more likely to have murdered a Caucasian than a non-Caucasian victim. Death row inmates were less likely to know their victims and more likely to have a codefendant. Psychiatric and organic findings did not differ among the groups, but the rate of organic findings and substance abuse was high in all three groups.
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Violent versus nonviolent stalkers. THE JOURNAL OF THE AMERICAN ACADEMY OF PSYCHIATRY AND THE LAW 1998; 26:241-245. [PMID: 9664259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Medical records of 42 pretrial detainees charged with stalking in South Carolina from January 1992 to January 1996 were reviewed. The group was divided into 22 nonviolent and 20 violent stalkers. Stalkers were classified as violent if they had associated charges involving bodily harm to their victims or if they met the criteria for South Carolina's legal definition of aggravated stalking. Variables compared included age, sex, marital status, level of education, substance abuse, Axis I diagnosis, military history, organicity, and whether the victim was a casual associate or had a previous attachment to the stalker. There were no statistically significant differences between the groups. Approaching statistical significance was the finding that violent stalkers were more likely to have had a previous attachment to their victims, and nonviolent stalkers were more likely to be casually associated with their victims.
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Abstract
New information has challenged our traditional concepts that the forms and functions of PLA(2) are highly homologous, suggesting now that distinct PLA(2)s may be assigned distinct functions in normal and pathological processes. The nonpancreatic type II 14-kDa PLA(2) and the recently identified type IV "cytosolic" 85-kDa PLA(2) are the two forms most studied in inflammation. Observations in the past suggested that the type II 14-kDa PLA2 is a secreted enzyme that functions extracellularly. Evidence is now emerging that the type II 14-kDa PLA(2) or its recently discovered low-molecular-weight isoforms may be localized and act intracellularly. In view of this, a more complex notion of distinctly functioning PLA(2)s in arachidonic acid release and/or eicosanoid generation can be envisioned. A comparison of the structural and biochemical features of the type II 14-kDa and the 85-kDa PLA(2)s reveals that the enzymes are more distinct than similar. These two enzymes would appear to have distinctly different genetic and biochemical regulatory mechanisms, suggesting that their functions could be quite distinct. Inhibitors of the 14-kDa PLA(2) and to a lesser extent the 85-kDa PLA(2) have been used to obtain a greater understanding of their cellular roles. The concept that the two distinct enzymes might hydrolyze arachidonic acid from different pools and/or supply distinct metabolizing systems in a single cell system has emerged. At this time an intriguing hypothesis can be formed suggesting distinct functional modalities for the two the PLA(2) enzymes in a single cell system. Evidence continues to build implicating the role of the type II 14-kDa PLA(2) in disease, providing a strong rationale for targeting this enzyme in designing novel antiinflammatory therapeutics.
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The role of platelet-activating factor (PAF) and the efficacy of ABT-491, a highly potent and selective PAF antagonist, in experimental allergic rhinitis. J Pharmacol Exp Ther 1998; 284:83-8. [PMID: 9435164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Platelet-activating factor (PAF) may be an important mediator of allergic rhinitis. In the present study we evaluated the effectiveness of a recently described PAF antagonist (ABT-491) in rat and guinea pig models of allergic rhinitis. PAF, when perfused through the nasal passages of anesthetized Brown Norway rats, provoked an acute increase, measured as dye leakage, in nasal vascular permeability evident within 15 min after exposure to PAF. ABT-491, given orally 1 hr before PAF challenge, inhibited the response in a dose-related manner (ED50 = 0.3 mg/kg). Intranasal perfusion with ovalbumin in rats sensitized to the antigen 18 to 21 days before challenge also induced an increase in vascular permeability. The antigen-induced leakage was inhibited a maximum of 74% (P < or = .001) by pretreatment with ABT-491 (3 mg/kg p.o.). An antihistamine (mepyramine, 10 mg/kg i.p.), a serotonin antagonist (methysergide) and a 5-lipoxygenase inhibitor (A-79175) also exhibited efficacy in this model (56%, 87% and 65% inhibition, respectively). Nearly complete inhibition (93%, P < or = .001) of the response was achieved by coadministration of ABT-491 and methysergide. In guinea pigs intranasal administration of PAF resulted in increased airway resistance that was inhibited in a dose-dependent manner by oral administration of ABT-491 (ED50 = 1 mg/kg). Antigen-induced nasal airway resistance, triggered by exposure of sensitized animals to aerosolized ovalbumin, was also inhibited by ABT-491 (maximum inhibition 64%, P < or = .05, 10 mg/kg p.o.). The effectiveness of the antagonist was increased to 80% protection by coadministration with either an antihistamine or a 5-lipoxygenase inhibitor, agents which were separately insignificant in blocking the response to antigen. These results suggest a therapeutic utility for ABT-491, perhaps in combination with other anti-inflammatory agents, in the treatment of allergic rhinitis.
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Discovery and evaluation of a series of 3-acylindole imidazopyridine platelet-activating factor antagonists. J Med Chem 1998; 41:74-95. [PMID: 9438024 DOI: 10.1021/jm970389+] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Studies conducted with the goal of discovering a second-generation platelet-activating factor (PAF) antagonist have identified a novel class of potent and orally active antagonists which have high aqueous solubility and long duration of action in animal models. The compounds arose from the combination of the lipophilic indole portion of Abbott's first-generation PAF antagonist ABT-299 (2) with the methylimidazopyridine heterocycle moiety of British Biotechnology's BB-882 (1) and possess the positive attributes of both of these clinical candidates. Structure-activity relationship (SAR) studies indicated that modification of the indole and benzoyl spacer of lead compound 7b gave analogues that were more potent, longer-lived, and bioavailable and resulted in the identification of 1-(N, N-dimethylcarbamoyl)-4-ethynyl-3-[3-fluoro-4-[(1H-2-methylimidazo[4,5-c] pyrid-1-yl)methyl]benzoyl]indole hydrochloride (ABT-491, 22 m.HCl) which has been evaluated extensively and is currently in clinical development.
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Abstract
Dramatic advances in psychopharmacology, the increased number of psychiatric rehospitalizations, and the advent of automated methods for processing information have all served to make more urgent psychiatry's need for a common language. In order to determine if psychiatry has a current common language, twenty-eight recognized experts from medical centers across the country were questioned regarding what categories, areas, and items of information they felt should be recorded in a mental status examination from one diagnostic interview. Results indicate that a basis for both a traditional and relevant common language in psychiatry does exist when viewed from the perspective of describing a patient's current mental status. Each psychiatrist must strive to overcome a tendency in the profession to develop a unique, elite and often incomprehensible vocabulary.
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Expression, release, and regulation of human TNF alpha from stable transfectants of HEK-293 cells. Inflamm Res 1997; 46 Suppl 2:S127-8. [PMID: 9297544 DOI: 10.1007/s000110050138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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ABT-491, a highly potent and selective PAF antagonist, inhibits nasal vascular permeability associated with experimental allergic rhinitis in brown Norway rats. Inflamm Res 1997; 46 Suppl 2:S133-4. [PMID: 9297547 DOI: 10.1007/s000110050141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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Ex vivo inhibition of beta-thromboglobulin release following administration to man of ABT-299, a novel prodrug of a potent platelet activating factor antagonist. Inflamm Res 1997; 46:272-7. [PMID: 9266276 DOI: 10.1007/s000110050186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE AND DESIGN ABT-299 is a prodrug that is converted by serum esterase to a potent platelet activating factor (PAF) antagonist (A-85783). In order to evaluate the pharmacological activity of this antagonist in man the effect of ABT-299 given to healthy volunteers on ex vivo PAF-induced beta-thromboglobulin (beta-TG) release in blood was assessed. SUBJECTS 37 healthy male volunteers, age 18 to 40 (mean age of 23.6 years) and free of medication, participated in the study. TREATMENT Subjects were administered intravenously 0.8 mg, 2 mg, or 70 mg doses of ABT-299 (6-7 subjects per group) or placebo (9 subjects, pooled). METHODS Peripheral blood taken over 12 h after dosing was used for ex vivo beta-TG release and, in the case of the 70 mg dose, measurement of plasma drug concentration. Data were compared by Student's t-test. RESULTS All three doses produced highly significant inhibition (p < 0.005 compared to predose values) of PAF-induced beta-TG release (units/ml plasma +/- SEM) 12 h after drug administration (54 +/- 14 vs. 405 +/- 51, n = 8; 79 +/- 23 vs. 480 +/- 127, n = 7; 21 +/- 10 vs. 327 +/- 72, n = 6, respectively) whereas there was no significant difference in beta-TG release in the placebo group (449 +/- 90 vs. 307 +/- 49, n = 9). Inhibition was associated with the rapid appearance in plasma of A-85783 and the pyridine N-oxide metabolite of A-85783. Within 2 h, the plasma concentration of the metabolite exceeded that of the parent drug. Both the parent drug and the metabolite exhibited potent in vitro inhibition of PAF-induced beta-TG release (A2 values of 4 and 1 nM respectively). CONCLUSIONS These studies are the first to illustrate the utility of the beta-TG release assay for assessing ex vivo activity of PAF antagonists. These studies also demonstrate that the administration of ABT-299 to man results in potent, long lasting inhibition of PAF-mediated platelet activation, due in part to the pyridine-N-oxide metabolite, and support the potential therapeutic utility of this prodrug in treating PAF-mediated diseases.
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Abstract
ABT-491 (4-ethynyl-N, N-dimethyl-3-[3-fluoro-4-[(2-methyl-1H-imidazo-[4,5-c]pyridin-1-yl)methy l]benzoyl]-1H- indole-1-carboxamide hydrochloride) is a novel PAF (platelet-activating factor) receptor antagonist with a K(i) for inhibiting PAF binding to human platelets of 0.6 nM. Binding kinetics of ABT-491 to the PAF receptor is consistent with a relatively slow off-rate of the antagonist when compared to PAF. Inhibition of PAF binding is selective and is correlated with functional antagonism of PAF-mediated cellular responses (Ca2+ mobilization, priming, and degranulation). Administration of ABT-491 in vivo leads to potent inhibition of PAF-induced inflammatory responses (increased vascular permeability, hypotension, and edema) and PAF-induced lethality. Oral potency (ED50) was between 0.03 and 0.4 mg/kg in rat, mouse, and guinea-pig. When administered intravenously in these species, ABT-491 exhibited ED50 values between 0.005 and 0.016 mg/kg. An oral dose of 0.5 mg/kg in rat provided > 50% protection for 8 h against cutaneous PAF challenge. ABT-491 administered orally was also effective in inhibiting lipopolysaccharide-induced hypotension (ED50 = 0.04 mg/kg), gastrointestinal damage (0.05 mg/kg, 79% inhibition), and lethality (1 mg/kg, 85% vs. 57% survival). The potency of this novel antagonist suggests that ABT-491 will be useful in the treatment of PAF-mediated diseases.
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Stalkers: the South Carolina experience. THE JOURNAL OF THE AMERICAN ACADEMY OF PSYCHIATRY AND THE LAW 1997; 25:541-545. [PMID: 9460040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Medical records of 18 pretrial detainees charged with stalking were evaluated at a forensic unit in Columbia, South Carolina from January 1992 to December 1994 and their records were compared with those of 18 offenders in the same unit randomly matched for sex, race, and whether associated crimes were violent or not. Compared variables included age, marital status, level of education, substance abuse, Axis I diagnosis, prior psychiatric hospitalizations, military history, and organicity. Significant findings show that alleged stalkers were better educated, less likely to be married or to abuse substances, and more likely to have military training and organicity when compared with other offenders. The prototypical stalker in this study is a single, educated male who is likely to have military training as well as some degree of organicity. He is less likely than other offenders to abuse substances. Replication studies are needed.
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Are prostaglandins major mediators in perennial allergic rhinitis? Rhinology 1996; 34:130-5. [PMID: 8938878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Certain prostaglandins acting as inflammatory mediators have been implicated in the aetiology of perennial allergic rhinitis (PAR). Inhibition of prostaglandin synthesis in the nasal mucosa might therefore influence the symptoms associated with PAR. A randomised, doubleblind, placebo-controlled cross-over trial using 0.1% Diclofenac eye-drops has been conducted to investigate this hypothesis. Diclofenac, a non-steroidal anti-inflammatory drug (NSAID), reduces prostaglandin synthesis through the inhibition of the cyclo-oxygenase pathway. Twenty-five patients with significant PAR and positive skin tests to relevant perennial allergens were recruited and two drops of the given preparation were administered bilaterally q.d.s.. Thirteen patients completed the study. Nasal symptom score (itch, rhinorrhoea, sneezing, and blockage), smell test score, saccharin transit time, total nasal airflow resistance, and nasal inspiratory peak flow measurements were obtained at each of three study visits. No significant treatment effects were found. The daily nasal symptom score over the entire study period showed no significant variation. Adverse effects such as local invitation, dry nose or throat were rare. No untoward changes in haematological, biochemical profiles and urinalysis occurred. In conclusion, topical 0.1% Diclofenac eye-drops applied nasally have no significant effect on PAR. Prostaglandins alone may not play a major role in mediation of symptoms in this condition.
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Abstract
The purpose of this study was to examine the association between nine measures of limb and trunk flexibility and running economy. Within a week prior to running economy assessment, and after 10 min of jogging at 3.13 m.s-1, 19 well-trained male sub-elite distance runners underwent two complete sets of lower limb and trunk flexibility assessments. Runners then completed two 10-min running economy assessment sessions on consecutive days at 4.13 m.s-1 following two 30-min sessions of treadmill accommodation at 4.13 m.s-1. Intraclass correlation coefficients indicated that the repeated flexibility measurements were highly reliable (X R = 0.92 +/- 0.09), as were the two running economy appraisals (R = 0.99). Correlational analyses revealed that dorsiflexion (r = 0.65) and standing hip rotation (r = 0.53) were significantly (P < or = 0.05) associated with the mean aerobic demand of running, such that runners who were less flexible on these measures were more economical. Although speculative, these results suggest that inflexibility in certain areas of the musculoskeletal system may enhance running economy in sub-elite male runners by increasing storage and return of elastic energy and minimizing the need for muscle-stabilizing activity.
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Short-term changes in 10-km race pace aerobic demand and gait mechanics following a bout of high-intensity distance running. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1996; 73:267-72. [PMID: 8781856 DOI: 10.1007/bf02425486] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Following treadmill accommodation and a 3-day period of tapered running, ten well-trained male distance runners [x maximum oxygen uptake (VO2max) = 71.3 ml.kg-1.min-1] performed two 10-min level treadmill runs designed to assess running economy at 90% VO2max. Video recordings were obtained during the last minute of each run to quantify selected gait descriptors. Two to 3 days following the second economy run, each subject completed 30 min of high-intensity (HI) running at 90% VO2max. One 2, and 4 days after the HI run, subjects repeated the 10-min economy runs. Compared to pre HI-run values, no significant change (P > 0.05) in running economy was observed during the post-HI runs. Biomechanical analyses also revealed that running style remained unaltered after the HI run. These results support earlier findings obtained on moderately trained subjects featuring measurement of running economy and gait mechanics at less-demanding intensities and suggest that among well-trained athletes, 30 min of HI running does not elicit an increase in VO2 or disrupt gait mechanics over the short term in subsequent distance runs performed at near-maximal speeds.
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Aerobic demand of running shoes designed to exploit energy storage and return. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 1996; 67:102-105. [PMID: 8736000 DOI: 10.1080/02701367.1996.10607931] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Relationships between running economy and temporal EMG characteristics of bi-articular leg muscles. Int J Sports Med 1996; 17:128-33. [PMID: 8833715 DOI: 10.1055/s-2007-972820] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Relationships between running economy (RE; submaximal VO(2) for a given running speed) and the temporal EMG characteristics of bi-articular leg muscles were quantified in a group of well-trained runners. Nine subjects completed three test sessions: a determination of maximal aerobic demand (VO(2)max); an accommodation session at the experimental speed of 4.13 m.s(-1) and a session during which EMG and RE data were collected simultaneously at the experimental speed of 4.13 m.s(-1) Measures of muscle onset, on-time durations, and on-time coactivation durations were calculated from the following muscles: rectus femoris, medial hamstrings, lateral hamstrings, and gastrocnemius. Nonparametric correlations between RE and EMG characteristics displayed both positive and negative relationships and exhibited a wide range of values. Two EMG measures were significantly correlated (r > 0.67) with RE. Earlier onset of rectus femoris during swing phase and a shorter duration of hamstring - gastrocnemius coactivation during swing were associated with more economical runners. Although not statistically significant, correlation coefficients calculated for measures of coactivation during stance and RE ranged from -0.42 to -0.65. This trend indicates that individuals who exhibited a greater amount of coactivation between bi-articular muscles during the stance phase of the running cycle tended to be more economical. These relationships suggest different activation patterns in bi-articular muscles between economical and uneconomical runners.
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Attentional strategy use by experienced distance runners: physiological and psychological effects. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 1995; 66:142-150. [PMID: 7644834 DOI: 10.1080/02701367.1995.10762221] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The purpose of this investigation was twofold: (a) to compare most and least economical runners on use of attentional strategies and (b) to determine whether the least economical runners within the subject sample could improve running economy (RE) with the use of an active associative (relaxation) attentional strategy. Subjects (N = 36) completed an initial assessment of attentional style and RE; then the 12 least economical runners ran in each of three laboratory sessions using control, passive associative, and active associative attentional strategies. Results showed that the most economical and least economical runners did not differ in associative style use. The most economical runners, however, reported less dissociation use and more use of relaxation than did the least economical runners. No significant physiological or psychological changes were associated with any of the three attentional strategy conditions. The findings are related to possible differences in how most and least economical runners use associative strategies.
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RELATIONSHIP BETWEEN BODY MASS AND THE AEROBIC DEMAND OF RUNNING IN WELL-TRAINED DISTANCE RUNNERS. Med Sci Sports Exerc 1995. [DOI: 10.1249/00005768-199505001-00170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Variation in the aerobic demand of running among trained and untrained subjects. Med Sci Sports Exerc 1995; 27:404-9. [PMID: 7752868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Variation in the aerobic demand (VO2) of submaximal running was quantified among trained and untrained subjects stratified by performance capability. Based on a retrospective analysis of seven published studies, maximal aerobic power (VO2max), and submaximal VO2 values were analyzed in three groups of trained distance runners (Category 1 (C1) (elite runners; N = 22), Category 2 (C2) (sub-elite runners; N = 41), and Category 3 (C3) (good runners; N = 16), and one group (N = 10) of untrained subjects (Category 4; C4). Results indicated that VO2max differed significantly (P < 0.05) across groups, such that C1 > C2 > C3 > C4. Analysis of submaximal VO2 data also revealed that C4 was more uneconomical than C1, C2, and C3 and that C2 and C3 were less economical than C1. Average within-group variability in submaximal VO2 was similar across categories and a marked overlap of minimum, mean and maximal economy values existed across categories. These data suggest that 1) trained subjects are more economical than untrained subjects, 2) elite runners display better economy compared to less-talented counterparts, and 3) economical and uneconomical runners can be found in all performance categories.
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Abstract
The purpose of this study was to assess the relationship between VO2max and the aerobic demand of running (VO2submax) in elite distance runners. On at least one occasion, VO2max and VO2submax values were obtained on 22 male subjects (mean age = 27 +/- 2 yrs; mean height = 178.6 +/- 6.8 cm; mean body mass = 64.1 +/- 5.6 kg; mean 10 km run time = 28.89 +/- 1.05 min) training for the 1994 Olympic Trials. Subjects performed 6-min, submaximal level-grade treadmill runs at four speeds (ranging from 4.47 to 5.50 m.s-1) to determine VO2submax. VO2 during each run was calculated by analyzing a 2-min gas sample collected during the last 2 min of running. These values were expressed relative to distance traveled and averaged to derive an overall VO2submax value. Shortly following these submaximal runs, VO2max was measured. When more than one set of VO2submax and VO2max data were available for a particular subject, the average of all tests was used. Results indicated that mean VO2max and VO2submax values were 75.8 +/- 3.4 ml.kg-1.min-1 and 184.6 +/- 8.6 ml.kg-1.km-1, respectively. Correlational analyses also revealed a significant relationship (r = 0.59; p < 0.01) between VO2max and VO2submax. These data suggest that among similarly-performing elite distance runners, a positive relationship exists between VO2max and the aerobic demand of running.
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