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Biomedical subjects

J Victor

Publications and source records attributed to J Victor.

At least 19 recordsLinked to original sources
PubMed1997

Low production of interferon gamma is related to disease progression in HIV infection: evidence from a cohort of 347 HIV-infected individuals.

A total of 347 HIV-seropositive individuals attending the Department of Infectious Diseases at Rigshospitalet in Copenhagen and 110 age- and sex-matched healthy controls not at risk for HIV infection were included in this study. Interferon gamma (IFN-gamma) production was measured in whole blood of 223 HIV-seropositive individuals (68 had developed AIDS at enrollment) and 99 healthy sex- and age-matched controls 4.5 hr after challenge with phytohemagglutinin. HIV-infected individuals for whom IFN-gamma production was measured were followed with a median follow-up time of 2.89 years (range, 0.02-4.54 years) from the date of enrollment. Survival analysis was performed considering three different end points: (1) a CD4 count below 100 cells/mm3, (2) an AIDS diagnosis defined according to the 1993 Centers for Disease Control definition, and (3) death. The production of IFN-gamma was highly increased in the blood of HIV-infected individuals without AIDS, but decreased in the blood of AIDS patients (both compared to controls). In the HIV-infected individuals, the total production of IFN-gamma was positively correlated with the number of CD8+ T lymphocytes and with the number of CD16+/CD56+ natural killer cells and negatively correlated with serum levels of beta2-microglobulin. Low levels of IFN-gamma production were associated with an increased risk of experiencing a CD4 count below 100 cells/m3 and death, analyzed in both univariate analysis and in multivariate analysis adjusting for CD4 counts and age. Thus, changes in production of IFN-gamma seem to be truly related to the risk for disease progression in HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Graft selection in anterior cruciate ligament reconstruction--prospective analysis of patellar tendon autografts compared with allografts.

A prospective study of 73 arthroscopic anterior cruciate ligament reconstructions using either a patellar tendon autograft or an allograft was made to assess any difference in clinical outcome. Allocation was by availability of an allograft. There were 48 autografts and 25 allografts. Evaluation was by clinical examination and physical tests. At follow-up 2 years after operation, there were no statistically significant differences between the two groups in mobility or in physical tests, but KT-1000 evaluation showed a slightly greater anterior translation in the autografts at 6 months and one year, although at 2 years the allografts developed greater anterior laxity. Cybex testing showed greater quadriceps strength at 6 months and one year in the allografts, but at 2 years the strength was greater in the autografts. Re-rupture occurred in 3 allografts. ACL reconstruction with a patellar tendon allograft does not produce a significant functional deficit. Full quadriceps recovery takes 2 years. Allografts are not recommended as stability deteriorates with time.

Adolescent↗
PubMed1997

Decreased short-term production of tumor necrosis factor-alpha and interleukin-1beta in human immunodeficiency virus-seropositive subjects.

Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were measured by ELISA in 4.5-h, lipopolysaccharide-stimulated whole blood cultures of 347 human immunodeficiency virus type 1-infected patients and 107 healthy seronegative controls. The production of TNF-alpha was decreased in both AIDS and non-AIDS patients, whereas the production of IL-1beta was decreased in AIDS patients only. The production of TNF-alpha and IL-1beta was positively affected by the concentrations of CD14+ monocytes and CD8+ lymphocytes; however, in patients, the concentration of CD4+ lymphocytes and the presence of AIDS had a negative effect on cytokine production as determined by multiple linear regression analysis. It is concluded that low whole blood cytokine production is mainly caused by low numbers of cells, but a functional defect may also exist.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Accuracy and mean duration of different protocols of head-up tilt testing.

Based on the results of our study, > 95% of patients with a positive passive tilt test are also positive during 3 micrograms/min, and especially 5 micrograms/min, isoproterenol tilt test. A proposed time-saving protocol would be to initiate the test with an isoproterenol infusion and to perform a 45-minute passive tilt only in those patients with a positive 5 micrograms/min (an infusion rate reported to have an excessive low specificity) isoproterenol tilt test, and to consider only those with symptoms associated with objective changes during this latter test as "finally positive." An alternative option would be to perform a 45-minute passive tilt only in those patients with a negative 3 micrograms/min isoproterenol tilt test.

Adolescent↗
PubMed1996

Reflex response times of vastus medialis oblique and vastus lateralis in normal subjects and in subjects with patellofemoral pain syndrome.

Various authors have indicated that imbalance of the vastus medialis/vastus lateralis muscles might lead to patellofemoral pain syndrome. However, few reports have been published to substantiate such a hypothesis. The purpose of this study was to attempt to set a scale for the normal reflex response times of the vastus medialis oblique and vastus lateralis muscles after a patellar tendon tap and to determine if patellofemoral pain syndrome patients have an alteration in this firing sequence. A control group of 80 healthy adults was compared with a group of 19 patellofemoral pain syndrome patients. Results indicated that the reflex response time of the vastus medialis oblique was significantly shorter than the reflex response time of the vastus lateralis in the normal subjects (p < or = .01). When comparing these data in the patellofemoral pain syndrome group, a significant earlier firing was obtained from the vastus lateralis in comparison with the vastus medialis oblique (p < or = .01). These findings suggest that a reversal has occurred in the firing pattern of the vastus medialis oblique and vastus lateralis muscles in patellofemoral pain syndrome patients. The results indicate an alteration in the neuromuscular answer of the vastus medialis oblique and vastus lateralis muscles during a patellar tendon tap.

Adolescent↗
PubMed1996

[Value of thyroidectomy in amiodarone-induced hyperthyroidism. Apropos of 3 cases].

Amiodarone-induced hyperthyroidism in a relatively rare complication of long-term treatment with this molecule. It usually carries a good prognosis with regression being the rule after withdrawal of the drug although lethal forms have been reported. Conventional medical therapy (synthetic antithyroid drugs, steroids, betablockers) used in severe forms, is not always effective. In addition, amiodarone may be essential for the treatment of life-threatening, poorly tolerated arrhythmias, refractory to other forms of treatment. The authors report the cases of three patients treated with amiodarone for malignant arrhythmias who developed severe hyperthyroidism resistant to medical therapy and who were treated by total thyroidectomy. Surgery was followed by rapid resolution of the thyrotoxicosis without significant complications and immediate represcription of amiodarone. Thyroidectomy therefore seems a simple solution for amiodarone-induced hyperthyroidism allowing very rapid resolution of the hyperthyroidism and the possibility of immediate represcription of amiodarone.

Adult↗
PubMed1996

The Judet quadricepsplasty: a retrospective analysis of 16 cases.

Sixteen quadricepsplasties performed for severe extension contractures of the knee were reviewed. Preoperatively all cases showed a severe extension contracture with an average of 23 degrees flexion. Only two patients had more than 30 degrees flexion preoperatively. The average improvement in knee flexion at follow-up was 69 degrees with 11 (68.7%) patients achieving a final flexion of 90 degrees or more. In four cases there was a 15 degrees loss of terminal active extension. In one case a rapid recurrence of the contracture was seen during the initial postoperative weeks. One patient developed a deep infection, and another an acute compartment syndrome.

Adolescent↗
PubMed1996

[Is the presence of right ventricular high intensity signals sufficient for the diagnosis of right ventricular dysplasia?].

The aim of this study was to assess "morphological" MRI data (spin-echo) compared with cine-MRI in 10 patients with documented right ventricular dysplasia and 10 normal controls. Data was acquired with a 0.5 Tesla superconductor magnet associating sequences of spin-echo and gradient echo (cine-MRI). An abnormal high intensity signal was observed in spin-echo in 9 out of the 10 patients. They were present on the anterior and sub-tricuspid walls of the right ventricle (8/10) and in the pulmonary infundibulum (8/10). A dyskinetic zone corresponding to the abnormal signals was detected in 8 patients. In the control group, only one subject had an abnormal high intensity signal and no dyskinesis could be detected. The association of high intensity signals and dyskinesis would seem to be very specific of right ventricular dysplasia. On the other hand, a high intensity signal alone may be observed in apparently normal subjects and would seem to be less specific.

Aged↗
PubMed1995

Defective natural immunity: an early manifestation of human immunodeficiency virus infection.

Cytotoxicity mediated by natural killer (NK) and lymphokine-activated killer (LAK) cells may be of significance in host defense against viral infections. This study included 347 patients infected with human immunodeficiency syndrome virus (HIV) type 1 and 110 controls. The NK cell activity, either unstimulated or stimulated with interferon-alpha (IFN-alpha) or interleukin-2 (IL-2), and the LAK cell activity were suppressed in patients, but the NK/LAK cell activity did not differ between patients with AIDS and patients without AIDS. However, the IFN-alpha-stimulated NK cell activity and LAK cell activity were reduced in patients with symptoms of HIV disease (CDCIV) when compared with asymptomatic patients (CDCII+III). When the data were analyzed by multiple linear regression, the percentage of CD4+ cells had a positive effect on these two parameters in patients without AIDS, whereas the percentage of CD4+ cells had no significant effect on unstimulated and IL-2-stimulated NK cell activity in these patients. In controls and AIDS patients, the percentage of CD4+ cells had no effect on NK/LAK cell activity in multiple linear models. The total number of CD16+ cells was low in patients compared to controls, whereas the percentages of CD16+, CD56+, and CD16+CD56+ were either normal or elevated. Therefore, the decrease in NK cell subpopulations did not contribute to the observed depression in NK/LAK cell activity in vitro. It is concluded that natural immunity is suppressed in HIV-seropositive patients primarily because of a qualitative defect of the NK/LAK cells. This qualitative defect includes a reduced responsiveness to IFN-alpha, which is progressive until the onset of symptoms, and possibly related to the loss of CD4+ cells.

Adult↗
PubMed1995

Illusory contours activate specific regions in human visual cortex: evidence from functional magnetic resonance imaging.

The neural basis for perceptual grouping operations in the human visual system, including the processes which generate illusory contours, is fundamental to understanding human vision. We have employed functional magnetic resonance imaging to investigate these processes noninvasively. Images were acquired on a GE Signa 1.5T scanner equipped for echo planar imaging with an in-plane resolution of 1.5 x 1.5 mm and slice thicknesses of 3.0 or 5.0 mm. Visual stimuli included nonaligned inducers (pacmen) that created no perceptual contours, similar inducers at the corners of a Kanizsa square that created illusory contours, and a real square formed by continuous contours. Multiple contiguous axial slices were acquired during baseline, visual stimulation, and poststimulation periods. Activated regions were identified by a multistage statistical analysis of the activation for each volume element sampled and were compared across conditions. Specific brain regions were activated in extrastriate cortex when the illusory contours were perceived but not during conditions when the illusory contours were absent. These unique regions were found primarily in the right hemisphere for all four subjects and demonstrate that specific brain regions are activated during the kind of perceptual grouping operations involved in illusory contour perception.

Brain Mapping↗
PubMed1995

[Electrophysiological study for the diagnosis and prognosis of syncope of unknown origin].

OBJECTIVE: To evaluate, on the basis of long-term outcome, the value of electrophysiologic exploration for determining the cause of syncope of unknown origin after clinical examination and standard laboratory tests. METHODS: In 1985 and 1986, 109 consecutive patients with syncope of unknown origin underwent electrophysiologic exploration. The patients were divided into two groups. Baseline electrocardiogram was abnormal in 59 patients: cardiopathy (32%), ischemia (17%). In 44 of these patients, electrophysiologic exploration revealed major abnormalities requiring treatment (Group 1). No aetiology could be defined in 65 patients (Group 2). Patients were followed for 37 +/- 11 months. Three were lost to follow-up and 106 were retained for analysis. RESULTS: Morbidity and mortality were 25% and 16% respectively at the end of follow-up. Two sudden deaths were recorded, both in Group 1. Total mortality was greater in Group 1 (10 vs 6) so electrophysiologic exploration had defined a population at lower risk of sudden death and overall mortality. Relapse of syncope was observed in 27 patients (25% and 26% in Groups 1 and 2 respectively) due to rhythm disorders in 8, vasodepression in 1 and unknown origin in 18. CONCLUSION: The rate of recurrent syncope suggests these patients should have a second work-up in order to diagnose initially false negatives. Relapse raises the problem of electrophysiologic abnormalities and multifactorial mechanisms causing syncope of unknown origin.

Adult↗
PubMed1995

Carotid sinus syndrome: acute hemodynamic evaluation of a dual chamber pacing mode.

Cardiac pacing is the treatment of choice in patients with carotid sinus syndrome (CSS). Three different pacing modes were tested in 20 patients (16 males, 4 females; mean age 75 +/- 9 years) with documented symptomatic CSS. Three carotid sinus massages (CSM) were performed in each supine patient successively paced in random order in: DDI--the reference pacing mode; DDD--automatic mode conversion (DDD/AMC) allowing automatic switching from AAI to DDD when AV block occurs; DDD/AMC plus atrial acceleration (DDD/AMC+acc); and OOO (CSM without pacing) to determine whether the vasodepressive effect was still present 10 minutes after the preceding CSM. Intraarterial blood pressure was continuously monitored. Results were expressed as the value of the mean systolic BP at T0 + 3 s + 6 s ... T0 + 30 s divided by the value of the mean systolic blood pressure prior to onset of CSM. The drop in arterial blood pressure was more severe in the DDI mode than in DDD/AMC (P < 0.001) and DDD/AMC+acc (P < 0.0001) in 20 patients. In the OOO mode, the drop in arterial blood pressure was most marked and greater than in the DDI mode (P < 0.0001). The average time between start of the CSM and onset of the drop in blood pressure was the same in the three dual chamber modes. We conclude that the DDD/AMC mode significantly improves the vasodepressor response to CSM compared to the DDI mode. There is a current trend favoring DDD/AMC+acc over DDD/AMC.

Aged↗
PubMed1995

[Hyperthyroidism induced by amiodarone and hyperthyroidism induced by iodine. Histologic, immunohistochemical and ultrastructural aspects].

Amiodarone is a widely-used anti-arythmic drug that induces an iodine overload and, in 1 to 23% of the patients, a thyrotoxicosis. In a few cases, the thyrotoxicosis may be refractory to conventional pharmacological therapy, thus leading to thyroidectomy. We report the thyroid gland pathology in 5 thyroidectomies that were performed for uncontrolled thyrotoxicosis, induced by amiodarone (4 cases) and by Colchimax, another iodine-rich drug (1 case). Two cases have been studied by electron microscopy. Pathologic findings were: [1] colloid transformation of the parenchyma, [2] areas of follicular disruption with numerous foamy macrophages in the colloid, [3] regenerative areas and [4] a moderate T lymphocytic infiltration. No lysosomal lamellar inclusion body was found by electron microscopy. These lesions may be rather specific of an iodine toxicity. The pathogeny is still misunderstood, and probably complex. It may essentially involve toxic mechanisms, as well as immunologic or allergic mechanisms.

Adult↗
PubMed1994

Hepatitis A vaccine. A new convenient single-dose schedule with booster when long-term immunization is warranted.

A total of 162 anti-HAV-negative healthy adults were immunized with a single high dose (1440 ELISA units = 1 ml) of inactivated hepatitis A vaccine and a booster was given at month 6. Antibodies were measured after modification of a commercial ELISA kit, enabling quantification of titres down to 6 mIU ml-1. After 14 days, 96% of vaccinees had positive anti-HAV titres (> 20 mIU ml-1), and after 30 days all vaccinees had seroconverted. The geometric mean titres were 150 mIU ml-1 and 380 mIU ml-1 respectively. The booster dose at month 6 elicited a dramatic (25-fold) increase in antibody titres from 125 to 3090 mIU ml-1. Thus a single dose may be a convenient alternative to immunoglobulin for inducing rapid seroprotection, with a booster dose at month 6 ensuring long-lasting protection.

Adolescent↗
PubMed1994

[Arrhythmia and conduction defects in polymyositis].

The prevalence of cardiac complications of dermatomyositis and polymyositis is generally underestimated. The authors report the case of heart block as the presenting symptom of the disease, situated in the atrioventricular node. Initially paroxysmal, it eventually became permanent. It was associated with atrial (fibrillation and flutter) and ventricular hyperexcitability (ventricular tachycardia in runs). Myocardial biopsy provided histological proof of the cardiac disease and the definitive link between the nodal conduction defect and the polymyositis.

Adult↗
PubMed1994

[Value of magnetic resonance imaging in cardiac sarcoidosis. Apropos of a case].

The authors report the value of magnetic resonance imaging (MRI) in a case of cardiac sarcoidosis presenting with syncopal ventricular tachycardia (VT). The images were acquired in a monomorphic multiplane echo spin sequence. A 25 millisecond interval was chosen for the weighted T1 sequence. A second weighted T2 sequence using an interval of 70 milliseconds was then performed. The acquisitions were recorded in these planes axial, sagittal and coronal. The thickness of the sections was 8 mm. MRI was useful in locating the exact site and extent of the lesions; this enabled the operators to perform "guided" endomyocardial biopsies. In the weighted T1 sequences, these biopsies showed zones of increased intramyocardial signal density, more pronounced on the second weighted T2 sequences. Moreover, it was possible to follow up the outcome of these lesions with steroid therapy and observe their partial regression. These non-specific appearances may be observed in all inflammatory conditions but, in the context of systemic sarcoidosis, are very suggestive of cardiac involvement. In view of the clinical latency of cardiac sarcoidosis and its poor prognosis, the non-invasive character of MRI should make this a routine investigation in all patients with systemic sarcoidosis.

Adult↗