Biomedical subjects

M Devidas

Publications and source records attributed to M Devidas.

14 recordsLinked to original sources

PubMed2000

Venous valve station changes in "primary" and postthrombotic reflux: an analysis of 149 cases.

The purpose of this study was to analyze valve station changes noted during venous valve reconstruction and the associated outcome. One hundred and forty-nine valve reconstructions were available for analysis at the time of surgical exploration; the venous valve was graded according to valve station changes (VS grades) from zero through six. Ascending venography was analyzed by a similar grading system and the two methods were compared. The results of this analysis showed that valve station wall changes are frequently present in patients with deep venous reflux and pose technical challenges during valve reconstruction; the outcome, however, appears unaffected. Grade 0 to 1 valve station changes are predominantly due to "primary" reflux, with an occasional instance of postthrombotic etiology. Grade 2 or 3 valve station changes are roughly evenly divided between phlebosclerosis of primary reflux and postthrombotic etiologies. The mechanism of onset of reflux with preservation of valve cusps in the latter group of postthrombotic cases is probably different from currently accepted theories of evolution of postthrombotic changes. Postthrombotic valve damage is variable, and the valve station anatomy may be sufficiently preserved in some patients to allow direct valve repair.

Endothelium, Vascular↗

PubMed1998

Axial transformation of the profunda femoris vein.

PURPOSE: To highlight a special subset of cases of venous stasis in which the profunda femoris vein enlarges to a variable extent (axial transformation) to compensate for severe postthrombotic changes in the accompanying superficial femoral vein. METHODS: Among 500 consecutively treated patients with severe venous stasis, 57 patients had axial transformation of the profunda femoris vein. Venous obstruction and reflux were assessed by means of arm-foot pressure differential, ambulatory venous pressure measurement, air plethysmography, and duplex examination. Ascending and descending venograms also were obtained. A variety of valve reconstruction techniques were useful in correcting reflux in the enlarged profunda femoris vein and the companion postthrombotic superficial femoral vein. RESULTS: In 55% of patients the profunda femoris vein was larger than normal and provided partial outflow from the leg through a profunda-popliteal connection, but the superficial femoral vein was still the dominant outflow tract (grades I and II). In 36% of patients the profunda femoris was the dominant outflow tract from the leg, and in another 9% it was the sole axial outflow tract (grades III and IV). The skin changes of advanced venous stasis were present among 92% of patients and frank ulceration among 88%. Antireflux operations on the profunda femoris vein and companion superficial femoral vein, including ligation and division in some instances, were well tolerated. Despite a postthrombotic cause, obstruction did not worsen after surgical treatment, and reflux improved according to most laboratory measurements. Complete ulcer healing was obtained with the surgical techniques described. The actuarial recurrence-free survival rates were 90% 1 year and 66% 5 years after treatment. CONCLUSION: Axial transformation of the profunda femoris vein is present in a subset of instances in which severe postthrombotic changes are present in the companion superficial femoral vein. Profunda femoris reflux is invariably present in these instances because of compensatory dilatation and enlargement of this vessel. Simultaneous valve repair of the axially transformed profunda femoris vein and companion superficial femoral vein to abolish reflux yields excellent long-term results and healing of stasis ulceration.

Actuarial Analysis↗

PubMed1998

Saphenectomy in the presence of chronic venous obstruction.

BACKGROUND: The results of saphenectomy in patients with morphologic and functional obstruction were compared with those in patients without obstruction. Excision of secondary saphenous varices associated with deep venous obstruction has long been considered contraindicated for fear of compromising its collateral contribution. Recent advances in accurate functional assessment of venous obstruction make it possible to test this concept. METHODS: Saphenectomy was carried out in 51 limbs without morphologic or functional obstruction and 64 limbs with varying grades of venous obstruction. Significant deep venous obstruction on ascending venography was present in the latter group. Functional assessment of obstruction was based on the arm/foot venous pressure differential technique, outflow fraction measurements, and outflow resistance calculations. Valve reconstruction was carried out in conjunction with saphenectomy in 81% of cases. RESULTS: Saphenectomy was clinically well tolerated in both groups, and there was no difference in outcome as measured by objective tests for obstruction; improvement in reflux and calf venous pump function was largely similar. Among seven limbs with severe preoperative venous obstruction (grade III or IV), five (70%) had significantly improved obstructive grading, presumably as a result of elimination of reflux flow. CONCLUSIONS: The traditional admonition against removal of secondary varices should be reexamined. Saphenectomy may be indicated in postthrombotic syndrome with mixed obstruction/reflux. The procedure is clinically well tolerated and without malsequelae. Improvement in reflux parameters without significant worsening of objective measures of obstruction is documented in this group.

Chronic Disease↗

PubMed1998

A method for determining patient oral care skills: The University of Mississippi Oral Hygiene Index.

The plaque control record (O'Leary index) appears to be a commonly used oral hygiene index for assessing oral health skills. This index provides sufficient information for patient education; however, the time involved in data collection reduces its value. Most other indices limit the number of teeth and surfaces and function well for researchers, but are limited for patient education. A new oral hygiene index was developed based on the concepts of the Periodontal Screening and Recording (PSR). The highest score obtained in each buccal and lingual sextant is recorded. In addition, proximal and gingival plaque are noted separately. This study assesses the index for inter- and intrarater reliability and validity. Two calibrated hygienists examined 47 patients 3 times. The University of Mississippi Oral Hygiene Index (UM-OHI) was recorded for times 1 and 3, the O'Leary for time 2. There was a strong positive correlation between scores obtained for both hygienists for each method and repetition. The intrarater reliability was high for the 2 methods and also over time for the UM-OHI. Pearson's correlation coefficients ranged from 0.79 to 0.92. Paired t-tests used to compare scores for the 2 hygienists over time showed significant differences. Despite observer bias, these data seem to indicate that the UM-OHI has sufficient reliability and validity to be used as a health education teaching tool.

Calibration↗

PubMed1997

A comparison of two different bronchial cuff designs and four different bronchial cuff inflation methods.

OBJECTIVE: To compare directly measured pressures at the cuff/trachea interface that are associated with two different bronchial cuff designs and four different methods of bronchial cuff inflation suggested for use with one-lung ventilation. DESIGN: In vitro study. SETTING: Experimental laboratory in a university-affiliated hospital. INTERVENTIONS: The bronchial cuffs of two different endotracheal tubes were inflated using one of four different methods of determining the cuff volume and pressure necessary to "just seal" the bronchus and obtain lung separation; positive-pressure test, negative-pressure test, CO2 analysis, and a new test using an anesthesia ventilator. When each method predicted the "just-seal" state, the pressure at the cuff/bronchus interface as well as cuff inflation pressure and volume were recorded. MEASUREMENTS AND MAIN RESULTS: Although the new test was incompatible with the bronchial blocker, the other three tests all accurately predicted lung separation with the Univent, with no significant differences in pressures exerted on the trachea. However, when used with the double-lumen tube, the new test produced significantly lower measured parameters than the other inflation methods. CO2 analysis did not reliably predict bronchial seal with the double-lumen tube. CONCLUSIONS: To achieve lung separation with the lowest pressure on the trachea, the new test is the most appropriate method for use with the double-lumen tube; however, the negative-pressure test appeared to be the easiest and fastest method for use with the bronchial blocker. Although the bronchial blocker was associated with lower pressures transmitted from the cuff to the trachea, the in vitro model cannot predict which bronchial cuff design would be superior in vivo.

Adult↗

PubMed1997

Psychopathologic risk factors for intentional and nonintentional injury.

OBJECTIVE: Trauma has a high rate of recurrence, suggesting that some people are more injury-prone than others. This study was performed to evaluate some of the psychological and social factors that might influence the likelihood of traumatic injury. METHODS: A case-control study was conducted to evaluate the relationship between selected psychosocial factors and traumatic injury. At a Level I trauma center, victims of intentional trauma (excluding attempted suicide), victims of nonintentional trauma, and patients undergoing elective surgery were interviewed by a person blinded to the purposes of the study. They were given an intelligence test and underwent a structured interview, yielding psychiatric diagnostic categories established in the third edition of the Diagnostic and Statistical Manual of Mental Disorders, Revised (DSM-III-R). RESULTS: Trauma patients were younger than elective surgery patients (p < 0.01) and were more likely to be men (p < 0.01). Victims of intentional injury had a higher probability of alcohol use (p < 0.01) and admitted illicit drug use (p < 0.001) than either nonintentional injury victims or elective surgery patients. Victims of intentional injury were more likely to be unemployed than those in the other two groups (p < 0.02), whereas elective surgery patients were more likely to be retired (p < 0.05) or to be disabled (p < 0.0001). The average intelligence score was slightly above the median in the nonintentional trauma group and in the control group (55th percentile and 54th percentile, respectively), compared with a mean intelligence score equivalent to the 35th percentile in the victims of intentional trauma (p < 0.001). Thirty percent of elective surgery patients met diagnostic criteria for at least one category of psychopathology, compared with 50% of nonintentional trauma patients, and 63% of intentional trauma patients (p < 0.01, trauma vs. elective surgery). Logistic regression analysis identified six variables that were independently associated with an increased tendency to be a victim of trauma: younger age, lower intelligence, antisocial personality, mental retardation, depression, and low income. CONCLUSIONS: Victims of trauma, both nonintentional, and especially intentional, have a high incidence of psychopathology. Victims of intentional trauma have significantly lower intelligence scores than either nonintentional injury or elective surgery patients. The high incidence of unemployment, alcohol abuse, and illicit drug use in victims of intentional injury might provide several opportunities for trauma prevention programs. Underlying psychological disorders will have to be addressed to reduce the likelihood of becoming a victim of trauma.

Accident Proneness↗

PubMed1997

The immune microenvironment of human fracture/soft-tissue hematomas and its relationship to systemic immunity.

The immune environment of human soft-tissue injury is unstudied. We studied fracture soft-tissue hematomas (FxSTH) in 56 patients with high-energy bony fractures. FxSTH serum and mononuclear cells (MNC) as well as fracture patient plasma and blood MNC were studied. Twenty healthy controls donated plasma and MNC. Soluble tumor necrosis factor (TNF)-alpha, interleukin (IL-1 beta, IL-2, 6, 8, 10, 12, and interferon-gamma were studied by enzyme linked immunosorbent assay. Cells were studied by flow cytometry after cell-membrane stains for CD-14, TNF-alpha (mTNF), and human leukocyte antigen-DR, or intracellular stains for TNF (icTNF) and IL-10. Thirty-six patients with Injury Severity Score < 15 were analyzed further to evaluate the effects of isolated fracture on systemic immunity. Cytokines were rarely detectable in control plasma. TNF-alpha, IL-1 beta, IL-2, and interferon-gamma were rarely found in FxSTH serum or fracture patient plasma. All FxSTH sera were rich in IL-6, peaking before 48 hours (12,538 +/- 4,153 vs. 3,494 +/- 909 pg/mL, p = 0.02, U test). In Injury Severity Score < 15, IL-6 was not detectable in most early fracture patient plasma, but rose after 48 hours (p = 0.028). FxSTH serum IL-8 peaked after 48 hours (440 +/- 289 vs. 4,542 +/- 1,219 pg/mL, p = 0.006) and circulating IL-8 appeared after 72 hours. IL-6 and IL-8 showed gradients from FxSTH serum to paired PtS (p < 0.05, Wilcoxon). IL-10 was abundant (884 +/- 229 pg/mL) in FxSTH serum < 24 hours old. FxSTH serum IL-12 peaked late (3,323 +/- 799 pg/mL, day 4-7) then fell (p < 0.001, analysis of variance). Only IL-12 was higher in fracture patient plasma (1,279 +/- 602 pg/mL) than FxSTH serum (591 +/- 327 pg/mL) during the first 48 hours (p = 0.032, U test). On flow cytometry, control monocytes expressed 201 +/- 31 mTNF sites/cell, but icTNF was absent. mTNF was up-regulated after injury more in FxSTH monocytes (3,202 +/- 870 sites/cell) than peripheral blood monocytes (584 +/- 186 sites/cell) (p < 0.05 vs. peripheral blood monocytes by Wilcoxon, p < 0.001 vs. control monocytes by U test). Intracellular IL-10 was abundant in all MNC, but varied widely after injury. Fracture and peripheral blood monocytes expressed far less human leukocyte antigen-DR than control monocytes. Fractures create an inflammatory local environment. Proximal mediators are cell-associated and relatively confined to the wound, but soluble IL-6, IL-8, and IL-10 are abundant and probably exported. Systemic MNC have complex responses to local injuries. These may reflect the combined impact of multiple soluble cytokines initially generated within the wound. FxSTH appear to be a potentially important source of immunomodulatory cytokines in trauma.

Adolescent↗

PubMed1997

Neonatal cephalohematoma from vacuum extraction.

OBJECTIVE: To identify factors involved in the development of fetal cephalohematoma from vacuum extraction. STUDY DESIGN: Patients at > or = 34 weeks' gestation were randomly assigned to delivery by vacuum (n = 322) using the continuous (n = 164) or intermittent (n = 158) technique. Neonatal outcome with cephalohematoma was analyzed subsequently and related to prospectively recorded data. RESULTS: Approximately equal numbers of cephalohematoma were recorded in the two groups (continuous 20, intermittent 17; P = .686). Station at point of application (P = .008), increasing asynclitism (P < .001) and increasing application to delivery time (P = .002) correlated significantly with cephalohematoma. Only the last two factors achieved significance after stepwise multiple logistic regression analysis. Factors that did not achieve statistical significance were gestational age (P = .755), birth weight (P = .982), instrumental rotation (P = .896) and previous vaginal delivery (P = .051). CONCLUSION: In this prospective, randomized, controlled trial of vacuum-assisted delivery, the only predelivery factor found to predispose to neonatal cephalohematoma formation was increasing asynclitism. Although cephalohematoma formation was more likely to develop as the duration of vacuum application increased during delivery, only 28% of neonates exhibited this finding when the time from vacuum application to delivery exceeded five minutes.

Female↗

PubMed1996

Production of interleukin-10 in human fracture soft-tissue hematomas.

Clinical trauma suppresses immunity and experimental wound fluids have been shown to be immunosuppressive. To ascertain whether human wounds contain immunosuppressive cytokines, we assayed serum from fracture/soft-tissue hematomas (FSTH) of 22 patients for interleukin (IL)-10, transforming growth factor (TGF)-beta 1, and IL-4. Results were correlated to concurrent plasma cytokine concentrations in the same patients and in volunteer plasma. IL-10 was present in high concentration (1376 +/- 539 pg/mL) in all (7/7) FSTH < 24 h old. In FSTH > 24 h old, IL-10 was found intermittently and at lower levels (239 +/- 106 pg/mL, p = .011 vs. FSTH < 24 h old). IL-10 was rarely detectable in fracture patient plasma and never detectable (< 20 pg/mL) in normal plasma. No significant variations of IL-4 or total TGF-beta 1 were found in FSTH or plasma. FSTH are significant potential sources of IL-10 activity in trauma patients, which may be overlooked when only plasma is assayed. The potential for a relationship between cytokines found locally at sites of injury and clinical immune modulation in trauma requires further study.

Adult↗

PubMed1994

Glucose given after hypoxic ischemia does not affect brain injury in piglets.

BACKGROUND AND PURPOSE: Giving glucose before hypoxic ischemia worsens brain injury in piglets. Does giving glucose after hypoxic ischemia affect severity of injury? METHODS: Forty-three 0- to 3-day-old pigs were used. All piglets received 2 U/kg insulin before injury to prevent stress-induced hyperglycemia. Hypoxic ischemic brain damage was induced by clamping both carotid arteries and reducing arterial blood pressure to two thirds of normal by hemorrhage at time 0. At 15 minutes the fraction of inspired oxygen (FIO2) was reduced to 6%. At 30 minutes FIO2 was increased to 100%, the carotids were released, and the withdrawn blood was reinfused. The piglets were then randomized to receive either 2 mL/kg of 50% dextrose followed by 2 mL/kg per hour for 2 hours or an equal volume of saline. RESULTS: Neurological examination scores (20 is normal, 5 is brain dead, by blinded observer) at 1 day postinjury were similar in the two groups: glucose, median 15.5 (25th percentile, 12.2; 75th percentile, 18); controls, 15.6 (9.3, 18). Piglets were killed at 3 days with brain preservation at death. Pathological examination scores (sum of scores from cortex, hippocampus, and basal ganglia: 30 is normal, 3 is total necrosis) by blinded observer were similar in the two groups: glucose, 26 (18, 28); controls, 25 (16.5, 28); NS. CONCLUSIONS: Although elevated glucose levels during hypoxic ischemic injury worsen brain injury in the piglet, elevated glucose levels after injury do not affect the severity of the injury.

Animals↗

PubMed1993

Generalized logistic models for low-dose response data.

We discuss a generalization of the logistic response function of the form Pr(y = 1/x) = [1 + exp(- theta - beta'x)]-alpha, where alpha > 0. This function coincides with the usual logistic response when the shape parameter alpha is equal to one. We describe the use of this model for analysing cancer rates in mice for low-dose exposure to a known carcinogen. When estimating the low-dose responses, the errors associated with extrapolation are reduced when a priori knowledge about the rates among unexposed individuals is incorporated into the fitting procedures.

2-Acetylaminofluorene↗

PubMedDate not supplied

Shoulder dystocia and operative vaginal delivery.

Our objective was to determine the factors involved in the development of shoulder dystocia in association with operative vaginal delivery. In this prospective study, patients who were candidates for operative vaginal delivery were randomized either to forceps (N = 315) or vacuum with M-cup (N = 322) and timed from initial placement of instrument to final delivery. Data were gathered prior to and after instrumental delivery. Statistics used were Pearson chi square, Fisher's exact, analysis of variance, and multiple logistic regression. There were a total of 21 patients with shoulder dystocia in both groups (3.3% incidence). Discriminant factors that did nor meet significance included use of epidural analgesia (P = .12), station (P = .99), previous vaginal delivery (P = .99), fetal gender (P = .54), indication for operative vaginal delivery (P = .63), > 45 degrees rotation (P = .68), use of episiotomy (P = .62), maternal weight (P = .26), and maternal diabetes (P = .08). Nearly attaining significance in univariate analysis was randomization to vacuum (P = .052). Significant factors included gestational age (P = .03), time required to effect delivery (P = .007), and birthweight (P = .0001). When these factors were subjected to stepwise multiple logistic regression, three factors remained as significant associations with shoulder dystocia: randomization to vacuum (P = .04), time for delivery (P = .03), and birthweight (P = .0001). In this operative vaginal delivery trial, shoulder dystocia was strongly associated with large fetal size, longer time to delivery, and the use of vacuum for delivery.

Birth Injuries↗

PubMedDate not supplied

Presurgical window of carboplatin and surgery and multidrug chemotherapy for the treatment of newly diagnosed metastatic or unresectable osteosarcoma: Pediatric Oncology Group Trial.

PURPOSE: Relapse remains a significant problem in patients with metastatic osteosarcoma. The response to carboplatin of patients with newly diagnosed metastatic or unresectable osteosarcoma was assessed in an upfront phase II window, which was followed-up by surgery and intensive multiagent chemotherapy. PATIENTS AND METHODS: Thirty-seven patients, ages 3 to 23 years with histologically confirmed diagnoses of osteosarcoma, were treated between January 1992 and November 1994 with carboplatin 1,000 mg/m2 per dose administered as a 48-hour continuous infusion. Two courses were administered in 3-week intervals, depending on marrow recovery. After radiographic reevaluation, patients underwent surgical removal of tumor (if feasible) and then 40 weeks of chemotherapy with high-dose methotrexate, ifosfamide, doxorubicin, and cisplatin. RESULTS: One of the 37 evaluable patients demonstrated a partial response to carboplatin; there were no complete responses. Patients were additionally analyzed by the response of pulmonary metastases to therapy and the extent of tumor necrosis of the primary lesion. By these criteria, 8 of 37 (22%) of patients showed a response at one or more sites, whereas 20 of 37 (54%) had unequivocal disease progression. Severe myelosuppression was the major toxicity. The projected 3-year event-free and overall survival rates were 23.9% and 31.9%, respectively. Only 1 of 17 patients with unresectable disease or distant bone metastases remains alive, in contrast to 6 of 17 patients with the lung as their only metastatic site and two of three patients with resected regional bone metastases. CONCLUSIONS: Continuous-infusion carboplatin demonstrated limited activity as an upfront agent in patients with metastatic osteosarcoma at diagnosis, even at doses that result in severe and prolonged myelosuppression. Patients with isolated pulmonary metastases or resectable bone metastases have a longer median survival time and greater chance of long-term survival than do patients with unresectable bone disease, for whom the prognosis remains dismal.

Adolescent↗

PubMedDate not supplied

Sleep patterns in pregnancy: a longitudinal study of polysomnography recordings during pregnancy.

OBJECTIVE: To evaluate the differences in sleep of women throughout pregnancy compared with those of nonpregnant control subjects. STUDY DESIGN: Four pregnant women were studied longitudinally during their pregnancy using inpatient polysomnography. Measurements included electroencephalography, electrocardiography, and continuous-pulse oximetry. Four healthy nonpregnant women matched for age and weight were used as control subjects. The total sleep time was recorded, and percentages of each sleep stage were generated. RESULTS: Qualitative differences in sleep between pregnancy patients and control subjects were evident. Control subjects displayed a normal appearance of slow-wave sleep in stages 3 and 4 (delta sleep). When pregnant patients did display delta sleep, it appeared abnormal secondary to extensive alpha-wave intrusion. Even when including this abnormal delta sleep in a quantitative comparison, the pregnant patients had a significantly shorter percentage of total sleep time in delta sleep (4.9+/-1.9% vs 21.9+/-6.0%, p=0.03). CONCLUSION: Sleep in pregnancy is characterized by loss of normal slow-wave sleep. Thus, sleep stages 3 and 4 are shortened during pregnancy. This sleep alteration is persistent when followed longitudinally during pregnancy.

Adult↗