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Biomedical subjects

M Kumar

Publications and source records attributed to M Kumar.

At least 217 records · Page 12Linked to original sources
PubMed1994

Congenital coagulopathies and pregnancy: report of four pregnancies in a factor X-deficient woman.

Pregnancy in women with congenital coagulation factor deficiencies has been associated with adverse fetal outcomes. Recurrent spontaneous abortions, placental abruptions, and premature births are reported, the exact reasons for which are not clear, and management of such patients continues to be a challenge. We reviewed the outcome of four pregnancies in a patient with factor X deficiency, and looked at the effect of factor replacement therapy on pregnancy. Her first two pregnancies resulted in the birth of extremely premature babies at 21 and 25 weeks of gestation, both of which died in the neonatal period. The patient was treated with fresh frozen plasma for acute bleeding episodes during these pregnancies. In addition during her second conception she was given factor IX complex [Konyne] prophylactically, but only in the latter half of her pregnancy. During her next two pregnancies she was treated early on during pregnancy, with prophylactic replacement of factor X. She delivered healthy babies at 34 and 32 weeks of gestation, and they are both doing well. We therefore suggest possible mechanisms by which aggressive prophylactic factor support in a female with severe congenital coagulopathy, may improve on fetal outcome.

Adult↗
PubMed1994

Changes in cognitive coping strategies predict EBV-antibody titre change following a stressor disclosure induction.

Previous research has shown that emotional disclosure of traumatic or stressful events is associated with facilitating insight into the experience, improving mood, and modulating some aspects of the immune system. The current study examined how cognitive changes and experiential involvement during an emotional disclosure induction protocol relate to immune functioning, as measured by IgG antibody titres to the Epstein-Barr virus viral capsid antigen (EBV-VCA). Seventy-six college undergraduates were randomly assigned to either a disclosure induction or an assessment-only control condition. Experimental subjects met with an experimenter for three weekly 20-min individual sessions during which time they were asked to discuss a stressful or traumatic topic which they had previously discussed only minimally with others. Blood was drawn a week prior to the first session and at one week following the third session. Subjects completed the Impact of Event Scale (IES) after session 1 and at followup, and the extent of experiential involvement in disclosure during each session was assessed by means of the Experiencing Scale. Mood was assessed before and after each disclosure using the Nowlis Mood Adjective Checklist. Although the disclosure induction did not directly affect EBV-VCA antibody titres, individual differences in subjects' ability to involve themselves in the disclosure process and abandon their avoidance of the stressful tropic during the course of the 3-wk period were predictive of antibody decrements. These associations were more pronounced for individuals who disclosed older and more troublesome events.

Adaptation, Psychological↗
PubMed1994

Monitoring intrathecal temperature: does core temperature reflect intrathecal temperature during aortic surgery?

Paraplegia secondary to spinal cord ischemia is a common occurrence following proximal aortic surgery. Recent research has suggested that modest reductions in neuronal temperature (ie, a 2 to 5 degrees C reduction) may protect the central nervous system from ischemic injury, and several medical centers are now using modest whole body hypothermia in an attempt to protect the spinal cord during aortic surgery. However, to date, there are no reports to validate that reductions in core temperature will reduce intrathecal temperature during aortic surgery. In the present study, the correlation between core temperature, assessed with a pulmonary artery thermistor, and intrathecal temperature, assessed with a lumbar intrathecal thermocouple, were evaluated. Both devices were corrected for bias using a mercury thermometer standard. It was found that there was excellent correlation between pulmonary artery temperature and intrathecal temperature during all portions of the surgery (r = 0.948; P < 0.001). The regression line for the relationship was defined by the formula: intrathecal temperature = 0.98 x pulmonary artery temperature + 0.65. Furthermore, there was excellent correlation between bias-corrected intrathecal temperature and the temperature measured by commercially available, bias-uncorrected thermistors placed in the esophagus (r = 0.869; P < or = 0.001), urinary bladder (r = 0.873; P < 0.001), and pulmonary artery (r = 0.929; P < 0.001). Based on these data, it is concluded that there is a close correlation between intrathecal temperature and core temperatures during proximal aortic surgery, and commercially available thermistors provide sufficient accuracy to assess spinal cord cooling during attempts to protect the spinal cord from ischemic injury.

Aortic Aneurysm, Abdominal↗
PubMed1994

Cerebrospinal fluid dopamine in HIV-1 infection.

BACKGROUND: Increasing evidence suggests significant involvement of the basal ganglia in patients with HIV-1 infection. OBJECTIVE: To study the effect of HIV-1 infection on cerebrospinal fluid (CSF) dopamine levels. DESIGN: CSF dopamine levels were measured by high-performance liquid chromatography. SETTING: A university-based outpatient clinic in south Florida involved in clinical AIDS research. SUBJECTS: Twenty-two subjects were enrolled in a prospective, longitudinal study of the neurological complications of AIDS. Five subjects were HIV-seronegative, but at risk for HIV-1 infection, 11 were HIV-1-seropositive without neurological disease and six had HIV-1-related neurological disease. RESULTS: The CSF dopamine mean values were significantly lower in the HIV-1-seropositive group with (P < 0.0001) or without (P < 0.0001) neurological disease than in the HIV-seronegative group. There was a very strong correlation between CD4 lymphocyte counts and CSF dopamine levels (P = 0.004) in the neurologically symptomatic group (P = 0.0008), but not in the other two groups. CONCLUSION: HIV-1 infection appears to have an effect on the central nervous system dopaminergic systems, as reflected in levels of CSF dopamine.

Adult↗
PubMed1994

A hypercellulolytic mutant of Fusarium oxysporum.

Multiple mutagenesis of Fusarium oxysporum DSM 841 resulted in enhanced yields of cellulases. The hypercellulolytic mutant (NTG-19) secretes high levels of extracellular cellulases on different cellulosic substrates. Addition of surfactant, Tween-80, further increased enzyme secretion by about 30%. The results on hydrolysis of wheat straw by parent strain, DSM 841 and mutant NTG-19 cellulases also revealed a significant improvement in the hydrolytic potential of the cellulolytic enzymes from the mutant NTG-19.

Cellulase↗
PubMed1994

Diagnostic and prognostic significance of lactate dehydrogenase in cerebrospinal fluid in patients of meningitis.

Activity of lactate dehydrogenase was measured in cerebrospinal fluid in 60 cases of meningitis (35 pyogenic, 18 tuberculous and 7 viral). Thirty age and sex matched healthy controls were taken to find out its diagnostic and prognostic significance in meningitis. The cerebrospinal fluid lactate dehydrogenase activity was significantly higher (p < 0.001) in cases of pyogenic meningitis and tuberculous meningitis as compared to the control group. The maximum elevation was seen on the 1st day in all types of meningitis but the activity declined significantly thereafter in patients of pyogenic meningitis who recovered without complications. However, in 2 cases of pyogenic meningitis and 5 cases of tuberculous meningitis who survived with complications, the lactate dehydrogenase activity on subsequent estimations increased serially. Further, the basal lactate dehydrogenase activity in 9 cases of pyogenic meningitis (who expired) was higher than those who survived without complications. The basal lactate dehydrogenase activity in pyogenic meningitis was significantly higher (p < 0.05) as compared to tuberculous meningitis and viral meningitis patients (p < 0.02) in this study.

Adolescent↗
PubMed1994

Electrophysiological studies (MNCV and H-RL) in twin babies.

Twenty-six fullterm and eight preterm babies born of twin pregnancies were studied. Offsprings were subjected to measurements of weight, crown heel length and head circumference along with motor nerve conduction velocity (MNCV) and H-reflex latency (H-RL) at right median nerve. The preterm twins had significantly lower MNCV and higher H-RL. The electrophysiological parameters did not vary in first and second born twins as well as in heavier and lighter twins. Three pairs of twins were available for follow-up study.

Birth Weight↗
PubMed1993

Bilateral Wilms tumor. Review of outcome, associated abnormalities, and late effects in 36 pediatric patients treated at a single institution.

BACKGROUND: Patients with bilateral Wilms tumor have an increased incidence of associated abnormalities and nephrogenic rests and require individualized multimodality therapy for cure. The authors reported the associated abnormalities, outcome, complications, and late effects of treatment in a group of children with bilateral Wilms tumor treated at St. Jude Children's Research Hospital, Memphis, Tennessee, over a 28-year period. METHODS: The records of 36 consecutive pediatric patients diagnosed with bilateral Wilms tumor between 1962-1990 were analyzed. Biopsy material was also reviewed, with particular emphasis on characterization of nephrogenic rests and histology. RESULTS: Twenty-nine patients had synchronous tumors and 7 had metachronous lesions. Associated physical abnormalities were present in 12 patients and involved the genitourinary, cardiovascular, integumentary, and musculoskeletal systems. The overall survival for patients with metachronous tumors (71%) was similar to that for those with synchronous tumors (70%). There was no effect of age or the presence of nephroblastomatosis. Two patients with synchronous tumors initially treated with nephrectomy eventually required bilateral nephrectomies for contralateral recurrence after chemotherapy and radiation therapy. Nephrogenic rests were present in 22 of 30 evaluable patients. Two of three patients with metachronous tumors had intralobar nephrogenic rests. Bilateral renal salvage procedures were demonstrated to be technically feasible and effective in controlling disease without compromising renal function or survival. Late effects included scoliosis in three patients treated before 1970, cardiomyopathy in one patient who received 300 mg/m2 doxorubicin and 12 Gy pulmonary irradiation, and benign tumors in two patients, one of whom also had a bowel obstruction. Serum creatinine, urea nitrogen, and blood pressure were normal in 23 of 26 survivors. CONCLUSIONS: The authors' experience supports a favorable outcome with minimal late effects for patients with bilateral Wilms tumor who receive individualized therapy at pediatric oncology centers.

Child↗
PubMed1993

The fidelity and dynamic response of fluid-filled catheter systems for direct measurement of lumbar cerebrospinal fluid pressure.

OBJECTIVE: The purpose of this study was to determine the fidelity of pressure signals transmitted through long, narrow (epidural) catheters inserted into the lumbar intrathecal space. METHODS: Using a model of the spinal canal we tested three epidural catheters: 20-gauge Arrow, 20-gauge Abbott, 21-gauge Portex. We (1) determined the damping coefficient and natural frequency of the three catheters, (2) correlated the static pressures measured using the three catheters compared to the true pressure in the intrathecal space, and (3) compared the response time of the three catheters connected to transducers vs U-tube manometers. RESULTS: The three catheters had high damping coefficients (alpha) (Arrow, 0.75; Abbott, 0.85; Portex, 1.10) and low natural frequencies (Arrow, 15.23 Hz; Abbott, 12.83 Hz; Portex, 9.09 Hz). The dynamic response characteristics of the catheter with the largest internal diameter (20-gauge Arrow) were adequate to reproduce pulsatile cerebrospinal fluid pressure reliably. Smaller catheters tracked the mean pressure, although oscillations were damped. Static pressure measurements from all three catheters showed good correlation with test pressures (r = 0.99; p < 0.001). Using the U-tube manometer, it required 170, 140, and 130 minutes for the Portex, Abbott, and Arrow catheters, respectively, to equilibrate with a test pressure of 30 cm H2O. The rate of rise in the U-tube manometer pressure was limited by the rate of fluid flow through the catheters. CONCLUSIONS: We found that a catheter of at least 20 gauge connected to a transducer could record pressures in the cerebrospinal fluid compartment with a high degree of fidelity. The prolonged time to reach equilibrium made U-tube manometry unsuitable for clinical use.

Catheterization↗
PubMed1993

Defensiveness, trait anxiety, and Epstein-Barr viral capsid antigen antibody titers in healthy college students.

The relationship of individual differences in repressive coping styles with differences in antibody titer to Epstein-Barr viral capsid antigen (EBV-VCA) were investigated in a normal, healthy college population made up of people previously exposed to EBV. Each of 54 1st-year undergraduates completed a battery of physical-status questions and items pertaining to potential behavioral immunomodulatory confounds, along with the Taylor Manifest Anxiety Scale (T-MAS) and the Marlowe-Crowne Social Desirability Scale (MC-SDS). Ss reporting high and middle levels of anxiety had higher antibody titers to EBV, suggesting poorer immune control over the latent virus, as compared with the low-anxious group. Similarly, high-defensive Ss had higher antibody titers than their low-defensive counterparts, and neither group differed from the middle group.

Adolescent↗
PubMed1993

Abnormal pituitary-adrenocortical response in early HIV-1 infection.

The corticotropin-adrenocortical response to cold pressor challenge was investigated in a study of human immunodeficiency virus (HIV) infection. Data obtained from 16 HIV-1-positive and 28 HIV-1-negative subjects are presented in this report. After the insertion of a venicatheter and following 30 min of rest, the subjects immersed one of their hands in an ice-water mixture for 2 min, and serial blood samples were obtained for the determination of ACTH and cortisol levels. The results show a significant blunting in the ACTH response and marginally lower levels of cortisol, over all time points, in HIV-1-positive subjects compared to that in HIV-1-negative subjects.

Adrenocorticotropic Hormone↗