Biomedical subjects
Publications and source records attributed to T R Varma.
Sixty-two cases of thalamic pallidal and subthalamic surgery in Dundee were audited to assess the influence of physiological localisation on the procedure. Methods included microelectrode recording, evoked potential and stimulation techniques. Although anatomical localisation is improving with modern techniques, the physiological information is still modifying the surgery in 67% of cases.
Patients undergoing elective surgery for removal of brain tumors, aneurysms, or other vascular malformations were administered a single oral dose of sparfloxacin (400 mg; 16 patients) or ciprofloxacin (750 mg; 5 patients) either 3 to 5 h or 22 to 26 h before surgery. Serum samples were taken from all patients at 0, 1, 3 to 5, 7 to 9, and 22 to 26 h after dosing; an additional serum sample was obtained at 48 h from patients who received sparfloxacin. A single sample of brain tissue was taken from all patients; a sample of cerebrospinal fluid (CSF) uncontaminated with blood was obtained from five patients. Serum and brain tissue samples were assayed by high-pressure liquid chromatography. Drug concentrations in brain tissue exceeded those in CSF by 1.8- to 19.4-fold. Kinetic modeling suggested that peak sparfloxacin concentrations in brain tissue may have occurred later than 3 to 5 h and that actual peak concentrations may therefore have been higher (up to 10 micrograms/g of tissue). The activities of ciprofloxacin and sparfloxacin as antagonists of the gamma-aminobutyric acid antagonist (GABAA) receptor were measured with the rat vagus nerve preparation. The 50% inhibitory concentration (IC50) of ciprofloxacin was 250 microM (95.25 micrograms/ml), but in the presence of biphenyl acetic acid (BPAA), the IC50 of ciprofloxacin was only 0.6 microM (0.23 microgram/ml). In contrast, the IC50 of sparfloxacin alone or in the presence of BPAA was > 300 microM (> 100 micrograms/ml). We conclude that the concentrations of ciprofloxacin and sparfloxacin in brain tissue may exceed serum drug concentrations and cannot be predicted from the concentrations in CSF. Sparfloxacin does not have any activity as a GABA antagonist, either alone or in the presence of BPAA, at the concentrations which are likely to be reached in human brain tissue.
Kallmann's syndrome is a rare cause of primary amenorrhea, with impairment of release of gonadotropin-releasing hormone and anosmia. We present a case in which Kallmann's syndrome had been diagnosed, but who also fulfilled the diagnostic criteria for anorexia nervosa. We discuss the diagnostic dilemma.
Layered tissue models are developed to estimate in situ ultrasound intensity during common obstetric examinations by incorporation of measured overlying tissue thicknesses with data on the attenuation properties of tissues. Results are compared with attenuation models recommended by the United States Food and Drug Administration (FDA) and National Council on Radiation Protection and Measurements (NCRP). For abdominal and transvaginal scanning in the first trimester, fixed attenuation models based on attenuation values of 1.2 dB/MHz and 0.6 dB/MHz, respectively, are representative of worst-case exposure conditions. For second and third trimesters, a fixed attenuation value of 0.8 dB/MHz is representative of worst-case exposure conditions. A fixed attenuation value of 1.0 dB/MHz is suggested for common Doppler examinations. The study suggests that the FDA-derating factor of 0.3 dB/cm.MHz may not give a conservative estimate of in situ intensity for certain obstetric examinations.
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The cause of essential (low-frequency) tremor is unknown and its relation to physiological (high-frequency) tremor is unclear. We assessed essential tremor in one patient before and after a stereotactic thalamic lesion. The procedure changed the size of the tremor in the right hand but not in the left. Persistence of a low-frequency component suggested that essential tremor was an additional feature superimposed on physiological tremor in this patient. The focus of essential tremor seems to be an autonomous central generator that is independent of physiological tremor mechanisms.
A successful pregnancy ending in live birth at term is very rare following genital tuberculosis, in spite of effective medical treatment for tuberculosis. The medical, surgical or combined treatments all are associated with relatively poor fertility outcome. In vitro fertilization and embryo replacement have been found to be successful in a few patients.
There is a high association between anterior placenta previa, placenta accreta and previous cesarean section. We report three cases which illustrate the particular danger of massive hemorrhage posed by placenta previa/accreta in a scarred uterus. As the incidence of cesarean section continues to rise worldwide, the problem of placenta previa/accreta is likely to become more common. We emphasize the need for each obstetric unit to have a protocol for dealing with massive hemorrhage.
A case of a 33-year-old woman with a right fronto-parietal extracerebral lesion is reported. This lesion had all the features of a colloid cyst. Colloid cysts outside the third ventricle have been only rarely reported, but apparently never outside the ventricular system.
Two cases of chronic adhesive spinal arachnoiditis following documented subarachnoid haemorrhage (SAH) are reported. Both cases progressed to severe spinal cord dysfunction with paraplegia. It is hoped that this case report will highlight this uncommon but extremely disabling complication of SAH.
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We studied a group of 247 patients out of 7725 patients who had an ultrasonic examination between 32 and 36 weeks gestation and were found to have oligohydramnios (amniotic fluid volume (AFV) less than or equal to 2.0 cm). We compared the features of labor and mode of delivery and perinatal outcome in this group with that of a normal control group of 247 patients who also had an ultrasonic examination between 32 and 36 weeks gestation and were found to have normal AFV (greater than 2.0 to less than 8.0 cm). The incidence of induction of labor, of elective cesarean section, of preterm delivery (less than 37 weeks' gestation) was significantly higher in the oligohydramnios group (study group) as compared with the incidence in the control group (P less than 0.05). The incidence of fetal distress in antenatal and intrapartum period, pH (less than or equal to 7.2), of low Apgar score (0-5), of intrauterine growth retardation (IUGR) (less than tenth centile) infants, of major fetal anomaly and perinatal mortality rate (PNMR) are significantly higher in the oligohydramnios group as compared with the incidence and PNMR in the normal control group (P less than 0.05). The ultrasonic finding of oligohydramnios should alert the clinician regarding the possibility of problems in labor and perinatal period.
Graafian follicle growth was studied by ultrasound scanning during the peri-ovulatory period in 64 ovulatory cycles in 32 infertile patients on cyclofenil treatment, and compared with a control group of 32 patients with confirmed ovulatory cycles assessed on the basis of serum progesterone levels in the middle of the second half of the cycle. The mean maximum diameters of the leading follicles before ovulation were 21.9 +/- 0.6 (S.E.) mm and 24.4 +/- 0.5 (S.E.) mm, respectively for the cyclofenil group and the normal control group (P greater than 0.05). In 79% of the cyclofenil stimulated group and 83% of the spontaneous ovulation group, ultrasonic evidence of ovulation was present between 12 and 36 h after the initial increase in urine LH levels. Ultrasound scanning was found to be simple, and a quick method of monitoring graafian follicle development and ovulation on cyclofenil therapy and the cycles were comparable to the spontaneous ovulatory cycles as assessed on the basis of graafian follicle diameter, and the time of ovulation. Cervical score was not found to be useful to assess ovulation time in the cyclofenil treated group since 31.3% achieved a score of 10 or more on day -4, 93.8% within 24 h of ovulation and 24% on day 3 following the ovulation.
We studied a group of 135 patients with polyhydramnios diagnosed on the basis of ultrasonic findings (greatest vertical diameter of the liquor column greater than or equal to 8.0 cm) between 32 and 36 weeks gestation (study group). We compared the obstetric characteristics and perinatal outcome of the study group with a similar number who constituted our control group. The incidence of women aged 20 years or less was higher in the study group (8.9%) compared with 4.5% in the control group. Of the 135 patients who were diagnosed to have polyhydramnios ultrasonically, the clinical diagnoses prior to referral for ultrasonic scanning, were, suspected large for date fetuses in 34 patients (25.2%), clinically suspected polyhydramnios in 28 (20.7%), gestational diabetes in 21 (15.6%) and insulin dependent diabetes in 6 (4.4%) compared with 13.3%, 5.2%, 3.0% and 0.7%, respectively in the control group (P less than 0.05). Preterm delivery occurred in 11.1% in the study group compared with the incidence of 6.7% in the control group. The incidence of fetal distress, low Apgar Score, macrosomic infants, major fetal anomalies, gross and corrected perinatal mortality rate and admission to special/intensive care nursery was significantly higher in the study group compared with that of the control (P less than 0.01). We found ultrasonic examination is a reliable technique to assess the amount of amniotic fluid volume and it alerts the clinician to possible future problems in pregnancy, labor and neonatal period.
A 60-year-old postmenopausal woman presented with evidence of hirsutism, alopecia and mild virilization. Clinical examination and biochemical abnormalities suggested that the source of androgen excess was ovarian, and an ovarian tumor was confirmed and removed at laparotomy followed by normal endocrine profile in the postoperative period.
Two hundred fifty subfertile men with idiopathic oligospermia (count less than 20 million/ml) were treated with mesterolone (100-150 mg/day) for 12 months. Seminal analysis were assayed 3 times and serum follicle stimulating hormone (FSH) luteinizing hormone (LH) and plasma testosterone were assayed once before treatment and repeated at 3, 6, 9 and 12 months after the initiation of treatment. One hundred ten patients (44%) had normal serum FSH, LH and plasma testosterone, 85 patients (34%) had low serum FSH, LH and low plasma testosterone. One hundred seventy-five patients (70%) had moderate oligospermia (count 5 to less than 20 million/ml) and 75 patients (30%) had severe oligospermia (count less than 5 million/ml). Seventy-five moderately oligospermic patients showed significant improvement in the sperm density, total sperm count and motility following mesterolone therapy whereas only 12% showed improvement in the severe oligospermic group. Mesterolone had no depressing effect on low or normal serum FSH and LH levels but had depressing effect on 25% if the levels were elevated. There was no significant adverse effect on testosterone levels or on liver function. One hundred fifteen (46%) pregnancies resulted following the treatment, 9 of 115 (7.8%) aborted and 2 (1.7%) had ectopic pregnancy. Mesterolone was found to be more useful in patients with a sperm count ranging between 5 and 20 million/ml. Those with severe oligospermia (count less than 5 million) do not seem to benefit from this therapy.
The history, diagnosis and management of two patients with premature ovarian failure who responded to estrogen replacement therapy is presented. Both women conceived and had a live healthy baby.
Pregnancy following a period of infertility was considered to be an increased risk for the fetus. During a period of 3 years (1983-85), 748 couples were seen at this infertility clinic; 515 women (68.9%) conceived, and were followed up and studied prospectively. Fifteen of these women moved out of the area. We analysed the results of pregnancies for the remaining 500, (Group 1) and compared them with the outcome for the total obstetric population (Group 2) during the same period. Mean age at conception in the infertility group (Group 1) was 31.8 (+/- 2.7, 2 SD) years, as compared with 23.7 (+/- 2.9, 2 SD) in the total hospital obstetric population (Group 2) (p less than 0.05). The incidences of spontaneous abortion for the two groups (8 and 6.2%) did not differ (p greater than 0.05). However, the incidence of ectopic pregnancy was higher (3.0%) in Group 1 than in Group 2 (1.5%) (p less than 0.01). The incidence of pre-existing hypertensive vascular disease (7.7%) complicating pregnancy and multiple pregnancy (4.1%) was significantly higher in Group 1 than in Group 2 (1.5% and 1.4% respectively), (p less than 0.01). The incidences of induction of labor (29.5%) and elective operative delivery (10.6%) were higher in Group 1 (p less than 0.01). The incidences of infants with birth weight below the tenth centile (12.9%), of fetal distress in labor (14.6%) and a low Apgar score (0-5) (9.5%), were higher in Group 1, but there was no difference in the perinatal mortality rate between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)