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Biomedical subjects

K R Gabriel

Publications and source records attributed to K R Gabriel.

At least 19 recordsLinked to original sources
PubMed1997

Neurofibromatosis.

Recent advances in molecular genetics and biochemistry have defined the chromosomal abnormalities present in neurofibromatosis type 1 and type 2. The protein deficiency responsible for each syndrome has been identified. Unfortunately, this rapid progress in basic science has not yet produced an effective treatment for the underlying pathology. Patients and physicians must still deal with the various clinical manifestations and complications of neurofibromatosis; the orthopedic aspects are well known. Modern imaging does permit more effective evaluation of the patient and the particular problem so that treatments can be optimized and complications minimized.

Bone Diseases↗
PubMed1995

Femoral lengthening in patients having abnormal ipsilateral hip or knee.

Femoral lengthening using the Wagner technique was performed for 13 patients with abnormal adjacent joints. An average of 6.3 cm (19.5%) of lengthening was achieved. Three patients had no difficulties during lengthening. Transient non-surgical problems identified were blood pressure elevation, nerve palsy, and psychiatric reactions. Significant obstructions or complications occurred 13 times in nine cases. These included contractures of ipsilateral joints, angulations of the lengthened femur, Wagner device slippage, nonunion, and late hip subluxation. Other authors have reported similar difficulties in patients with normal ipsilateral joints. In this series, the advantage of achieving greater length appeared to outweigh the complications.

Adolescent↗
PubMed1993

Clinicopathologic correlates in Alzheimer disease: assessment of clinical and pathologic diagnostic criteria.

The neuropathologic findings from a group of 123 patients who have come to autopsy from the Rochester Alzheimer Disease Project (RADP) are presented. Among these 123 cases, there were 94 demented subjects who met the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer Disease and Related Disorders Association (NINCDS-ADRDA) clinical criteria for the diagnosis of "probable Alzheimer disease," and 29 normal elderly controls. Autopsy confirmation of Alzheimer disease (AD) was based on the age-graded National Institutes of Health (NIH) consensus conference pathologic criteria. Using the NINCDS-ADRDA clinical criteria and the NIH pathologic criteria, the diagnostic accuracy was 88%, the sensitivity was 98%, and the specificity was 69%. Additional strict clinical and pathologic criteria developed by the RADP were applied in the final review of these cases to exclude all confounding causes of dementia, including cerebral infarcts. After applying these additional criteria, a subset of 62 cases of "pure" AD and "pure" control subjects was identified for a more detailed examination of neuritic plaques (NP) and neurons containing neurofibrillary tangles (NFT). The NP and NFT were counted in three subfields of hippocampus and two areas of association neocortex. The density of diffuse plaques (plaques lacking dystrophic neurites) was estimated on a semiquantitative basis. Results show that the AD patients and control groups could be distinguished from each other easily on the basis of mean NP and NFT counts, but there was sufficient overlap in the counts to present difficulty in diagnosing any individual case. Abundant diffuse plaque involvement and NFT in the neocortex were, however, seen only in AD cases.

Aged↗
PubMed1993

Comparison of native prothrombin antigen with the prothrombin time for monitoring oral anticoagulant prophylaxis.

BACKGROUND: Oral anticoagulation is most frequently monitored using the prothrombin time, but an alternative approach is measurement of native, fully carboxylated, prothrombin antigen (NPA). We have correlated results of the prothrombin time and NPA with development of venous thrombosis or bleeding complications in a clinical trial of warfarin prophylaxis following total hip arthroplasty to determine the potential value of NPA measurement for monitoring oral anticoagulation. METHODS AND RESULTS: Patients in one arm of a prospective, randomized trial received warfarin prophylactically beginning 10 to 14 days before total hip arthroplasty in a dose adjusted to prolong the international normalized ratio (INR) to 1.5 on the day of surgery and 2.5 after surgery. NPA was measured by ELISA, and the prothrombin time was measured using rabbit brain thromboplastin. Samples were tested from 97 patients, and data from 81 patients who had adequate venography were analyzed to correlate test results with occurrence of thrombosis. The prothrombin time and INR were less sensitive than NPA to the lowest intensities of anticoagulation, with the prothrombin time index increasing from 1.0 to 1.3 and the INR increasing from 1.0 to 2.0, whereas the NPA concentration decreased fourfold, from 200 to 50 micrograms/mL. There was little correlation between either the prothrombin time index or the INR and the development of thrombosis, whereas NPA concentrations were significantly higher on the day of surgery and on postoperative days 1, 3, 5, and 7 in patients who developed venous thrombosis. Higher concentrations of NPA were associated with an increased risk of venous thrombosis, but there was no relation between thrombosis and the prothrombin time index or INR. There was no significant correlation between surgical blood loss and prothrombin time index, INR, or NPA concentration. However, patients who received the largest number of transfusions on the day of surgery had significantly lower NPA concentrations than patients who required no transfusion. CONCLUSIONS: These results indicate that the NPA concentration more accurately reflects the antithrombotic effect of warfarin than does prothrombin time and may be superior in monitoring prophylactic oral anticoagulation.

Administration, Oral↗
PubMed1992

Comparison of warfarin and external pneumatic compression in prevention of venous thrombosis after total hip replacement.

OBJECTIVE: To compare the effectiveness and safety of warfarin and external pneumatic compression (EPC) in prevention of venous thrombosis after total hip replacement. DESIGN: Prospective, randomized trial in consecutive patients, with blinded assessment of the primary end point. SETTING: University medical center and large community hospital. PATIENTS: Patients over age 18 years scheduled for elective primary total hip replacement were eligible. Of 254 patients interviewed, 232 were randomized, 220 patients had surgery and received prophylaxis, and 201 had venography. INTERVENTIONS: Patients were randomly assigned to prophylaxis with a device providing bilateral sequential EPC to both the calf and thigh or to receive warfarin in a low-intensity regimen beginning 10 to 14 days preoperatively. Prophylaxis was continued until venography. MAIN OUTCOME MEASURES: Venous thrombosis was diagnosed by venography between postoperative days 6 and 8. Bleeding was assessed by surgical blood loss, transfusion requirements, changes in hematocrit, and clinically identified bleeding complications. RESULTS: The total incidence of venous thrombosis was virtually the same in the warfarin and EPC groups (31% vs 27%), but the distribution of thrombi was different. Proximal thrombosis occurred in 12% of patients in the EPC group compared with only 3% in the warfarin group (P = .012, 95% confidence interval for difference, 2% to 18%). In contrast, calf vein thrombosis was more frequent in the warfarin group (21%) than in the EPC group (12%) (P = .021, 95% confidence interval for difference, 0% to 18%). Most proximal thrombi in EPC-treated patients were located within 15 cm of the femoral head and were not continuous with thrombi in deep calf veins. The high incidence of proximal thrombosis in the EPC group resulted in termination of the study by the safety monitoring committee. Blood loss and bleeding complications were similar in the two groups. CONCLUSION: Warfarin therapy is significantly more effective than EPC in preventing serious proximal vein thrombosis after total hip replacement. The greater effectiveness of warfarin therapy in preventing proximal vein thrombi and of EPC in preventing thrombosis in the calf suggests that there are differences in the pathogenesis of thrombosis in these two locations.

Aged↗
PubMed1992

Prevalence of scoliosis in neurofibromatosis.

Experience in a comprehensive, multispecialty neurofibromatosis clinic leads the authors to suggest that the association of spinal deformity with neurofibromatosis is less frequent than usually assumed. Previously reported statistics may be partly attributed to preselection of patients seen by spinal surgeons, and to the predominant referral of patients having severe manifestations of neurofibromatosis. A diagnosis of neurofibromatosis 1, based on National Institutes of Health criteria, is confirmed for two hundred twenty patients at the clinic. Twenty-three of these patients have structural scoliosis. Nine patients have idiopathic type curves, eight have dystrophic scoliosis, four have dystrophic kyphoscoliosis, and two have dystrophic lordoscoliosis. The authors believe that 10% is representative of the true prevalence of spinal deformity in an otherwise unselected cross section of neurofibromatosis patients.

Adolescent↗
PubMed1992

Longitudinal radiologic evaluation of osteoarthritis of the knee.

Radiologic assessment appears to be an objective standard for longterm evaluation of osteoarthritis (OA) and it is inexpensive, quick, simple and noninvasive. We conducted a one year followup study of patients with OA of the knee to evaluate the reproducibility and validity of this evaluation. The intra and interobserver reproducibility of the radiologic variables were evaluated on 275 and 539 patients, respectively, and found to be satisfactory (intraclass coefficient of correlation above 0.70 for the evaluation of the space narrowing of the joint). During the one year followup study, there was a slight but statistically significant deterioration of the joint space narrowing, evaluated on a 6 grade scale on 360 patients (p less than 0.001). The changes in the joint space narrowing were more closely correlated with treatments received by the patients for OA (nonsteroidal antiinflammatory drug (NSAID) intake, synovial fluid aspiration) than with changes in the recorded clinical variables (pain on a visual analog scale, Lequesne algofunctional index). Moreover, some factors such as obesity, generalized OA and flares of OA appeared to be correlated with the deterioration of joint space narrowing. Further studies are necessary to confirm and/or explain the relationship between the deterioration of the joint space narrowing and such factors (i.e., NSAID intake, obesity, flares of OA, generalized OA), which were detected in this study.

Aged↗
PubMed1991

Anatomical variations in the course of the superficial peroneal nerve.

Eighty-five legs in forty-four cadavera were dissected to determine the course of the superficial peroneal nerve from its origin to its termination as dorsal cutaneous nerves of the foot. Particular attention was paid to the relationship of the nerve with the intermuscular septum between the anterior and lateral compartments of the leg. In sixty-two (73 per cent) of the legs, the nerve coursed within the lateral muscle compartment from its origin to its exit through the crural fascia. In twelve (14 per cent) of the legs, the nerve had a variable course in the lateral compartment, crossed into the anterior compartment, and passed through the fascia. In ten (12 per cent) of the legs, the nerve divided in two, with branches in both the anterior and the lateral compartment. In one leg, the nerve never lay deep to the peroneus longus but ran along the deep surface of the fascia before exiting distally. The nerve or its branches passed through the fascia three to eighteen centimeters proximal to the lateral malleolus.

Humans↗
PubMed1990

Biplots in biomedical research.

The biplot is a graphical display of multivariate data. A number of examples from biomedical research illustrate its use. Biplots allow for inspection of data preliminary to formal analysis, and can follow an analysis by the graphical inspection of residuals. The simplicity and intuitive appeal of these displays is stressed. An appendix indicates their method of construction and the software for producing them.

Humans↗
PubMed1990

Occipito-atlantal translation in Down's syndrome.

Several cases of occipito-atlantal instability have been reported in patients with Down's syndrome. However, standards for radiographic measurement and normal values for translational motion at the occiput-C1 level have not been established for the Down's patient. A retrospective analysis of 102 flexion and extension lateral cervical spine radiographs of 73 patients with Down's syndrome was performed. Patients with congenital cervical spine anomalies, C1-C2 instability, or previous neck surgery were excluded. Occiput-C1 translation was measured by the technique described by Wiesel and Rothman. In normal adult patients, occiput-C1 translation should be no more than 1 mm by this method. Analysis of the data demonstrated a range of 0 to 10 mm, with a mean of 2.62 mm and a standard deviation of +/- 1.94 mm. Only 30 sets of films (29%) representing 27 patients (37%) showed anteroposterior translation of 1 mm or less. This laxity was not dependent on patient age in the current study group. A review of these patients' medical records did not disclose any evidence of impaired neurologic function related to cervical spine instability. The authors' data suggest that the prevalence and magnitude of occipito-atlantal instability in Down's syndrome is greater than previously appreciated.

Adolescent↗
PubMed1990

Quantitation of venous clot lysis with the D-dimer immunoassay during fibrinolytic therapy requires correction for soluble fibrin degradation.

Plasma cross-linked fibrin-degradation products were analyzed using a D-dimer (DD) immunoassay in patients with deep vein thrombosis (DVT) or acute myocardial infarction (MI) treated with fibrinolytic therapy, and the results were correlated with clot lysis documented angiographically. In 13 patients with DVT, the mean DD concentration increased 10-fold (1,074 +/- 252 to 10,333 +/- 1,004 ng/ml) during therapy, but neither the peak level nor the DD concentration integrated over the course of therapy correlated with clot lysis. Since plasma DD can derive from degradation of soluble plasma fibrin as well as from thrombi, the contribution of the former was estimated by in vitro incubation of the pretreatment plasma with plasminogen activator. Subtraction of this value from the measured posttreatment DD concentration provided a "corrected" level that represented DD originating from lysis of thrombi. This modification resulted in improved correlation of DD levels with clot lysis. The mean corrected peak DD was higher in patients with successful thrombolysis (8,780 +/- 1,352 ng/ml) compared with patients without lysis (3,075 +/- 589 ng/ml, p less than 0.001). There was a moderate correlation between the volume of clot lysed and the corrected peak DD (r = 0.62) and a higher correlation with the corrected DD integrated over the course of treatment (r = 0.97). By contrast, the corrected DD concentrations were near zero in patients treated for MI with or without thrombolytic reperfusion, suggesting that fibrin in small coronary thrombi did not contribute significantly to total plasma DD during therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Prevention of venous thrombosis after total hip arthroplasty. Antithrombin III and low-dose heparin compared with dextran 40.

The anticoagulant action of heparin is mediated through antithrombin III, and the postoperative decrease in the plasma concentration of antithrombin III may contribute to the relative ineffectiveness of prophylaxis with low-dose heparin in preventing venous thrombosis after total hip arthroplasty. We conducted a prospective, randomized trial to compare the effectiveness of a regimen of antithrombin III, given intravenously once daily, and low-dose heparin with a regimen of dextran 40, given intravenously, in preventing venographically documented venous thrombosis after total hip arthroplasty. The results demonstrated an incidence of venous thrombosis of 4.9 per cent in patients who received antithrombin III and heparin; this was significantly lower than the incidence (28.6 per cent) in patients who received dextran 40 (p less than 0.005). Venous thrombosis occurred only in patients who had total hip arthroplasty with a cemented prosthesis (fourteen of fifty-seven patients, or 24.6 per cent); none of the twenty-six patients in whom a non-cemented prosthesis was used had venous thrombosis (p less than 0.01). Of the patients in whom a cemented prosthesis had been inserted, the incidence of venous thrombosis was lower in those who were treated with antithrombin III and heparin (7.4 per cent) than in those who were treated with dextran 40 (40 per cent) (p less than 0.005). Postoperative levels of antithrombin III were maintained at more than 90 per cent of the baseline level in patients who received it; this was significantly higher than in patients who received dextran 40.(ABSTRACT TRUNCATED AT 250 WORDS)

Antithrombin III↗
PubMed1987

Foot and ankle problems.

The most common reason for children presenting to the general or the pediatric orthopedist has to do with foot problems. The usual age group ranges from the neonate to preschool. The authors have made an attempt to present guidelines for our approach to foot problems other than clubfoot in these age groups and have rendered our recommendations for treatment. We feel that pediatric and general orthopedists will be able to utilize our methods in the management of the pediatric patient with the more commonly presenting foot disorders.

Ankle↗
PubMed1986

Cultural values and biomedical knowledge: choices in infant feeding. Analysis of a survey.

This paper presents a study of 313 parturient women and considers their choices to bottle or breast feed. It examines demographic and cultural factors statistically and focuses on the effect of knowledge or ignorance of benefits of either method of infant feeding. Most women are found to have some biomedical knowledge of the benefits of breast feeding. The choice of bottle or breast feeding is closely associated with several demographic factors and a number of cultural ideas. Women who bottle feed see some of their dietary and other health related practices as barriers to breast feeding. It recommends that health practitioners who decide that individual women and/or their infants may benefit from breast feeding, should engage in a dialogue with the women. Such a dialogue should focus, not so much on information, but on the woman's views about her dietary and other health practices. If the woman is given compelling health reasons she may see herself as capable of changing some practices long enough to breast feed.

Adolescent↗
PubMed1979

Do psychiatric patients fit their diagnoses? Patterns of symptomatology as described with the biplot.

Systems of psychiatric diagnosis have been regularly criticized for their low reliability and their inability to fit accurately the kinds of patients coming for treatment. To explore the reasons for these problems, this study utilizes a new method, the biplot, for defining groups of similar patients and the relationships of these groups to key symptom clusters. Using this technique to analyze data from a representative sample of first admissions for psychiatric disorder, results showed: a) symptom clusters representing the classical diagnostic categories, mania, schizophrenia, neurotic depression, and psychotic depression, were readily identified; b) however, only a few patients were clustered near these traditional syndromes. These findings suggest that although syndromes do exist that fit traditional diagnostic categories, the vast majority of patients fall between these syndromes, having characteristics from several of them. For most patients, forcing the diagnostician to choose among the categories requires an arbitrary decision that may contribute to dissatisfaction in the diagnostician who recognizes how misleading the diagnosis can be.

Adjustment Disorders↗