Psychiatric morbidity in children suffering from acute lymphoblastic leukemia

The study aimed at assessing the frequency of psychiatric disorders in children with acute lymphoblastic leukemia. Thirty consecutive subjects in the age range of 6-12 years were interviewed with the help of a symptom checklist soon after they had achieved their first remission. The children were also administered the Children's Depression Rating Scale and the State Trait Anxiety Inventory for Children. One-third (n = 10) of the subjects received a diagnosis according to the International Classification of Diseases, 9th ed. Ninety percent (n = 9) had emotional disorders. All the disorders were mild to moderate in intensity and were perceived to be easily treatable.

MR imaging of symptomatic osteochondromas with pathological correlation

OBJECTIVE

To demonstrate the value of MR imaging in the diagnosis and differentiation of the various symptomatic complications of osteochondromas, providing pathological correlation with emphasis on the usefulness of MR imaging as a single imaging modality in these patients.

DESIGN

We retrospectively reviewed all MR examinations of clinically symptomatic osteochondromas (30 patients) performed at our institution between March 1990 and October 1997.

PATIENTS

Thirty patients had clinically symptomatic osteochondromas during the study period. Twenty patients were male and 10 were female. There were five cases of multiple osteochondromatosis. Pathological correlation was available in 24 patients.

RESULTS AND CONCLUSION

Symptomatic complications included fracture (7%), osseous deformity limiting range of motion (23%), vascular injury (7%), neurological compromise (10%), bursa formation (27%) and malignant transformation (27%). MR imaging was able to diagnose or suggest the etiology for the clinical symptomatology in all cases, demonstrating that it is an ideal imaging modality in the diagnostic evaluation of symptomatic complications of osteochondromas and often avoids the need for further imaging.

Right ventricular endocarditis due to infection of pacemaker apparatus

This article describes an unusual case of endocarditis in a 73-year-old man with a permanent pacemaker. Echocardiography revealed vegetations in the right ventricle below the tricuspid valve only, and he required open heart surgery for removal of the pacemaker system. This case demonstrates the potentially protracted course of infective endocarditis many years after pacemaker insertion. It also emphasizes the importance of echocardiography in diagnosing right ventricular vegetations; and the need for total replacement of the endocardial pacing system whenever it becomes infected.

Primary angioplasty in acute myocardial infarction: West Virginia University experience

Primary angioplasty is a useful alternate treatment to open the occluded coronary arteries during the acute phase of a myocardial infarction associated with ST segment elevation. We describe our experience with 50 patients seen at West Virginia University Hospital in Morgantown over a period of one year.

Spontaneous regression of a tectal mass in neurofibromatosis 1

MR images showed an enhancing, enlarging mass in the tectum of the midbrain in a child with neurofibromatosis type 1. The mass was presumed to be a tectal glioma, which initially enlarged then regressed in size over a 3-year period and ceased to enhance. Although a tissue diagnosis was not available, we believe the temporal evolution of this lesion is strong presumptive evidence of a hamartoma. This case argues for the conservative management of patients with neurofibromatosis type 1 when possible.

The effect of anti-prolactin antibody on in vitro synthesis of a pregnancy-associated rat uterine glycoprotein

Experiments were conducted to study the hormonal (estrogen [E2], progesterone [P4] and prolactin [PRL]), regulation of synthesis of a pregnancy-associated glycoprotein (named Uterine Agglutinin or UA) in the Day 4 post coital (p.c.) rat uterus with antibody administration and immunohistochemistry. Of the antibodies used, it was shown that anti-PRL antibody was the most effective in reducing in vitro UA synthesis. The results suggested that in vitro UA synthesis could be correlated to serum PRL levels as analyzed by radio-immunoassay. Binding studies revealed that PRL bound specifically to the stromal cells of the rat uterus where UA is produced and localized.

A cost-effectiveness and cost-utility analysis of radiosurgery vs. resection for single-brain metastases

PURPOSE

The median survival of well-selected patients with single-brain metastases treated with whole-brain irradiation and resection or radiosurgery is comparable, although a randomized trial of these two modalities has not been performed. In this era of cost containment, it is imperative that health-care professionals make fiscally prudent decisions. The present environment necessitates a critical appraisal of apparently equi-efficacious therapeutic modalities, and it is within this context that we present a comparison of the actual costs of resection and radiosurgery for brain metastases.

METHODS AND MATERIALS

Survival and quality of life outcome data for radiation alone or with surgery were obtained from two randomized trials, and radiosurgical results were obtained from a multiinstitutional analysis that specifically evaluated patients meeting surgical criteria. Only linear accelerator radiosurgery data were considered. Cost analysis was performed from a societal view point, and the following parameters were evaluated: actual cost, cost ratios, cost effectiveness, incremental cost effectiveness, cost utility, incremental cost utility, and national cost burden. The computerized billing records for all patients undergoing resection or radiosurgery for single-brain metastases from January 1989 to July 1994 were reviewed. A total of 46 resections and 135 radiosurgery procedures were performed. During the same time period, 454 patients underwent whole-brain radiation alone. An analysis of the entire bill was performed for each procedure, and each itemized cost was assigned a proportionate figure. The relative cost ratios of resection and radiosurgery were compared using the Wilcoxon rank sum test. Cost effectiveness of each modality, defined as the cost per year of median survival, was evaluated. Incremental cost effectiveness, defined as the additional cost per year of incremental gain in median survival, compared to the next least expensive modality, was also determined. To calculate the societal or national impact of these practices, the proportion of patients potentially eligible for aggressive management was estimated and the financial impact was determined using various utilization ratios for radiosurgery and surgery.

RESULTS

Both resection and radiosurgery yielded superior survival and functional independence, compared to whole brain radiotherapy alone, with minor differences in outcome between the two modalities; resection resulted in a 1.8-fold increase in cost, compared to radiosurgery. The latter modality yielded superior cost outcomes on all measures, even when a sensitivity analysis of up to 50% was performed. A reversal estimate indicated that in order for surgery to yield equal cost effectiveness, its cost would have to decrease by 48% or median survival would have to improve by 108%. The average cost per week of survival was $310 for radiotherapy, $524 for resection plus radiation, and $270 for radiosurgery plus radiation.

CONCLUSIONS

For selected patients, aggressive strategies such as resection or radiosurgery are warranted, as they result in improved median survival and functional independence. Radiosurgery appears to be the more cost-effective procedure.

Central neurocytoma: a clinical study of response to chemotherapy

We report a case of central neurocytoma treated, after an initial partial resection, by chemotherapy, comprising etoposide, ifosfamide and carboplatin. A response was obtained and further treatment was given with surgery and radiotherapy. There have been no previous reports of response to chemotherapy in this relatively rare tumour.

Acute iron poisoning

Accidental iron ingestion is not uncommon in children and has become a leading cause of unintentional pharmaceutical ingestion fatality. Difficulty in obtaining urgent serum iron levels in majority of hospitals in India, lack of objective indices for starting and stopping the chelation therapy and the cost of chelation therapy, all pose a significant challenge for a clinician in managing an acutely intoxicated patient. This review emphasizes the need for early recognition and correct intervention of a child with acute iron overdose to avoid undue morbidity and mortality.

Increasing the availability of vasectomy in public-sector clinics

A program designed to improve the availability of vasectomy in public-sector clinics trained physicians at 43 facilities in no-scalpel vasectomy between 1993 and 1995. Among the 38 clinics that responded to a follow-up survey in 1996, the number of clinics providing vasectomies rose from 23 to 32, an increase of almost 40%, while the number of vasectomies performed rose by 18%. Seventeen of the 32 clinics performed more vasectomies after the training; 10 of the 17 had not previously provided the procedure. In-depth interviews with staff from seven sites that experienced large caseload increases and from seven that experienced decreases identified three elements for the successful establishment or expansion of vasectomy services-sufficient numbers of trained providers, funds to subsidize vasectomies for men who cannot afford them and activities to raise awareness about the availability of low-cost or free vasectomy.

Spinal cord motoneuron excitability during isoflurane and nitrous oxide anesthesia

BACKGROUND

Recent evidence suggests that the spinal cord is an important site of anesthesia that is necessary for surgical immobility, but the specific effect of anesthetics within the spinal cord is unclear. This study assessed the effect of isoflurane and nitrous oxide on spinal motoneuron excitability by monitoring the H-reflex and the F wave.

METHODS

Eight adult patients, categorized as American Society of Anesthesiologists physical status 1 or 2, who were undergoing elective orthopaedic surgery were anesthetized with 0.6, 0.8, 1.0, and 1.2 times the estimated minimum alveolar concentration (MAC) of isoflurane. Nitrous oxide was added in graded concentrations of 30%, 50%, and 70%, whereas the isoflurane concentration was decreased to maintain a total MAC of 1. The H-reflex of the soleus muscle and the F wave of the abductor hallucis muscle were measured before anesthesia and 15 min after each change of anesthetic concentration. Four or more trials of the H-reflex and 18 trials of the F wave were recorded at each concentration of anesthesia. The effect of the anesthetics on the H-reflex and F wave was analyzed using. Dunnett's test.

RESULTS

H-reflex amplitude was decreased to 48.4 +/- 18.6% of preanesthesia level at 0.6 MAC isoflurane and to 33.8 +/- 19.1% when isoflurane concentration increased from 0.6 MAC to 1.2 MAC. F wave amplitude and persistence decreased to 52.2 +/- 33.6% and 44.4 +/- 26% of baseline at 0.6 MAC isoflurane, and to 33.8 +/- 26% and 21.7 +/- 22.8% at 1.2 MAC isoflurane. Isoflurane plus nitrous oxide (total 1 MAC) decreased H-reflex amplitude to 30.4-33.3% and decreased F wave persistence to 42.8-56.3% of baseline.

CONCLUSIONS

Both isoflurane alone and isoflurane plus nitrous oxide decrease H-reflex and F-wave amplitude and F-wave persistence. These effects suggest that isoflurane and nitrous oxide decrease motoneuronal excitability in the human spinal cord. This may play an important role in producing surgical immobility.

Behavior of the H-reflex in humans following mechanical perturbation or injury to rostral spinal cord

In humans H-reflexes are suppressed during early spinal shock. In animals rostral cord injury results in loss of segmental reflexes within seconds. If H-reflexes persist under general anesthesia, can they be used to monitor the integrity of the rostral cord? In part I of this study, we recorded H-reflexes intraoperatively in 25 patients to elucidate general anesthesia effect. In 23 subjects, H-reflexes were consistently elicited, and within +/- 13% of the normalized group mean amplitude. In part II, we recorded H-reflexes in 31 patients during spinal cord surgery to elucidate H-reflex behavior immediately following rostral spinal cord injury. In 6, abrupt suppression of the H-reflex coincided with cord injury. In 4 of 6, suppression was transient and less than 50% of baseline; none of these patients developed neurological deficits. In 2, suppression exceeded 90% and persisted throughout surgery; both patients developed profound deficits. We conclude that (1) the H-reflex can be consistently elicited under general anesthesia in most patients, (2) rostral cord injury rapidly suppresses the H-reflex, and (3) the degree and duration of H-reflex suppression reflects the severity of the injury.

Computed tomography appearance of idiopathic aneurysm of the azygos vein

True idiopathic aneurysm of the azygos vein is a rarely described abnormality. The authors present a case of this anomaly in a 70-year-old woman with a history of rectal carcinoma. The aneurysm was found incidentally on computed tomography, performed to characterize the appearance of a lung nodule. The aneurysm decompressed when the patient was upright. The effects of respiratory and postural manoeuvres on the lesion are discussed and the computed tomography appearance is described.

FosB in the suprachiasmatic nucleus of the Syrian and Siberian hamster

The suprachiasmatic nucleus (SCN) generates circadian rhythms of behavior and hormone secretion in mammals, and integrates responses to light and nonphotic stimuli to synchronize such rhythms with the external environment. Previous studies have demonstrated a close association between the induction of the immediate early gene (IEG) c-fos in the SCN by light and phase shifts of circadian rhythms induced by light, but nonphotic stimuli (e.g., arousal), which also cause phase shifts, do not increase c-fos expression in the SCN. Because c-fos is now known to be a member of a large family of IEGs which can regulate transcription and thus cellular function, the aim of the current study was to determine whether induction of another member of this immediate early gene family, fosB, is associated with photic and nonphotic phase shifts. An antiserum that recognizes a unique peptide sequence derived from FosB was produced so that the expression of fosB could be investigated in cells within the SCN by immunocytochemical detection of its protein product. The regional distribution of FosB-immunoreactive (ir) cells in the SCN of Syrian and Siberian hamsters was broadly similar to that for c-Fos-ir cells. However, whereas c-fos expression in the SCN was constitutively low, but could be massively induced by light at particular circadian phases, FosB-ir cells were present at all circadian phases studied, irrespective of photic stimulation, and light only produced marginal increases in the number of FosB-ir cells compared with nonstimulated controls. Moreover, blockade of glutamatergic neurotransmission by pretreatment of hamsters with the NMDA receptor antagonist MK801 significantly reduced photic induction of c-Fos-ir cells, but did not influence the number of FosB-ir cells in the SCN. Finally, an arousing nonphotic stimulus known to cause phase advances in wheel-running behavior in Syrian hamsters did not alter significantly the number of FosB-ir cells in the SCN. These observations indicate that light and nonphotic stimuli are not potent regulators of fosB expression in the SCN. However, because fosB and c-fos can be present in the SCN at the same time after a light pulse, these studies indicate the potential for interactions with each other and with members of the Jun family in the regulation of the circadian timing system.

Neuroticism in a family practice population in India

This study was conducted to assess the prevalence of neuroticism and its correlation with the various sociodemographic factors and presenting complaints among patients attending a family practice outpatient clinic. One hundred and forty two consecutive patients attending the outpatient clinic were administered PGI Health Questionnaire N2. Higher incidence of neuroticism was observed in middle age group population, in females (especially housewives), unskilled workers, patients with lower educational status and those belonging to small and nuclear families. A significant number of such patients had presented with vague symptoms, were visiting the clinics frequently and had associated chronic diseases. The results suggest that patients visiting the family practice clinics frequently with multiple somatic complaints with no suggested organic basis should undergo an in-depth psychiatric evaluation.

Behavior problems in nephrotic syndrome

OBJECTIVES

To evaluate the adaptive competences and behavioral problems in children with nephrotic syndrome, and whether their mothers also showed features of psychosocial stress.

DESIGN

Prospective case-control study.

SETTING

Pediatric Out-Patient Department.

SUBJECTS

Seventy consecutive patients of nephrotic syndrome, between the ages of 4 to 14 years, and their mothers constituted cases. The control group, matched for age, sex and socioeconomic status comprised of 46 children and their mothers. The mother's description of the child's behavior, on the Child Behavior Checklist (CBCL), was obtained to assess behavioral problems and social competences. The level of anxiety in the mother was assessed using the PGI Health Questionnaire N2.

RESULTS

Children with nephrotic syndrome showed features of depressed, hyperactive or aggressive behavior. Somatic complaints, social withdrawal and poor school performance were also observed. These problems did not interfere with compliance to treatment and only 7 patients required psychological interventions. Boys with nephrotic syndrome had more hyperactive and aggressive behavior as compared to girls. The scores on the CBCL were well correlated with the anxiety scores of the mother.

CONCLUSIONS

These observations suggest the presence of minor behavior problems in a significant proportion of children with nephrotic syndrome. The severity of these problems may be related to the attitude of the mother towards the child's illness.

Coping and adaptation in parents of children suffering from acute lymphoblastic leukemia

The coping and adaptation of 30 parents of children suffering from A.L.L. (during first remission), was studied with the Thematic Apperception Test (TAT--Indian modification). Emotional distress was evident in the stories of 83%, only 37% maintained an expectation of a positive outcome. Parents' psychiatric morbidity was found to be associated with the gender of the parent, employment status, and on the TAT--with the expectation of an unfavourable outcome, feelings of lack of self efficacy and emotional distress. Particularly depression. A significant association between the presence of psychiatric disturbance in the children and the parents was also found.

Neuropsychological deficits in tests of executive function in asymptomatic and symptomatic HIV-1 seropositive men

There has been much debate about the exact nature and time of onset of the cognitive impairments associated with infection by the human immunodeficiency virus type 1 (HIV-1). Studies to date have not reached consistent conclusions. The present study comprised 22 asymptomatic and 18 symptomatic HIV-1 seropositive men, whose only risk factor for contraction of the virus was sexual intercourse, and 18 seronegative controls matched for age and IQ. Subjects were given computerized neuropsychological tests from the CANTAB battery, which assessed visuospatial memory, attention and executive function. Both the asymptomatic and the symptomatic HIV-1 seropositive subjects showed a selective pattern of deficits relative to the controls. In addition, the seropositive subjects were subtly but significantly impaired on tests of executive function but unimpaired on certain tests of visual memory. This finding supports an hypothesis that frontostriatal dysfunction occurs in HIV-1 infected individuals prior even to the expression of clinical symptoms.

Coping and adaptation in acute lymphoblastic leukemia

The coping and adaptation of 39 children (6-12 years) to Acute Lymphoblastic Leukemia was studied during the first remission with a projective technique--Children's Apperception Test (CAT-S). Seventy seven percent of the children gave adequate responses. Among these, disease awareness was present in 96%, expectation of a favourable outcome was held by 70%, though 61% evidenced emotional distress. Children's psychiatric morbidity was found to be associated with non-response to CAT-S, to anxiety related themes, and negatively with ability to maintain an expectation of a positive outcome.

The minimum alveolar concentration of isoflurane in patients undergoing bilateral tubal ligation in the postpartum period

BACKGROUND

The minimum alveolar concentration (MAC) of volatile anesthetics is decreased during pregnancy, but MAC in the early postpartum period has not been reported. The aim of this study was to determine the MAC of isoflurane and to evaluate the relation between MAC and serum progesterone and beta-endorphin in patients after delivery.

METHODS

Eight patients undergoing elective bilateral tubal ligation during general anesthesia in the early postpartum period (< 12 h postpartum) and eight patients undergoing this procedure in the late postpartum period (12-25 h postpartum) were studied. Eight patients undergoing bilateral tubal ligation more than 6 weeks after delivery served as control subjects. Anesthesia was induced with propofol and maintained with isoflurane in oxygen to a steady end-tidal concentration of 0.8-1.0 vol% for 10 min. Reaction to a standardized electric stimulation applied to the forearm was graded as positive (gross or delayed movement) or negative. By using the bracketing technique, the concentration of isoflurane was increased or decreased by 0.1 vol%, depending on the positive or negative responses.

RESULTS

The MAC (mean +/- SD) in patients in the early postpartum period was significantly less (0.75 +/- 0.17 vol%) than that in control subjects (1.04 +/- 0.12 vol%; P < 0.01) and that in patients in the late postpartum period (0.95 +/- 0.2 vol%; P < 0.05). The difference in MAC values between late postpartum and control was not significant (P > 0.05). There was an inverse correlation between progesterone concentration postpartum and time after delivery (r = -0.527; P = 0.036), but P = 0.744). There was no correlation between plasma progesterone or beta-endorphin and MAC by multiple regression (r = 0.166; P = 0.950).

CONCLUSIONS

Isoflurane MAC remains 28% less than normal within the 1st 12 h postpartum and then returns to normal 12-25 h after delivery.

Ankylosing spondylitis: lateral approach to spinal anaesthesia for lower limb surgery

We describe three patients with long-standing ankyolsing spondylitis (AS) who underwent lower limb joint surgery under spinal anaesthesia. At preoperative assessment, it was considered that intubation of the trachea was likely to be difficult or impossible and previous general anaesthesia was associated with increased morbidity. Midline approach spinal anaesthesia failed but the lateral approach was successful. Spinal anaesthesia was induced using a 24 gauge Sprotte (Pajunk) needle with 3.5 ml heavy bupivacaine 0.5% at the L3-4 interspace with the patients in the sitting position. This resulted in adequate sensory blockade for the surgical procedure. None of the patients required airway interventions but equipment and aids to secure airway were available.

Nasal mucus clearance in chronic smokers

Smokers were observed to have grossly prolonged nasal mucus clearance. It was also inferred that the persons smoking bidi/unfiltered cigarettes had significant depression of ciliary activity. The clearance was prolonged as the number of cigarettes smoked and the duration of smoking increased. It was greater among those who gave a history of nasal exhalation of inhaled smoke. Nasal mucociliary clearance measurement is easy to measure and can be a useful index in evaluating the effect of smoking on the ciliary activity of the mucosa of the respiratory tract.

Student learning

This paper reviews important practical aspects of student learning. Some student learn by memorizing important parts of the text by dividing the content into bits and pieces. In this approach, the surface approach, they may not be able to derive full meaning of the content. The other method used by the students is deep approach, wherein a student tries to understand the meaning of the materials. In medical education, it is important for the student to relate contents of study material to other ideas, and to map-put subject areas. In the present context, a medical student also needs to become an autonomous learner, for which a student needs to develop certain skills. Teachers have a significant role in providing opportunities to the students to learn actively and meaningfully. Learning outcome is related to characteristics of the student, the teachers, the institution, the learning styles and processing of the learned subject.

Laparoscopic gastrojejunostomy: a case presentation

Laparoscopic gastrojejunostomy is demonstrated as an alternative to open gastric bypass procedures. We performed the operative procedure safely and with reasonable anesthesia time, using stapling devices. It is hoped that further patient benefit will be obtained from this laparoscopic procedure in the future.

Current radiosurgery practice: results of an ASTRO survey. Task Force on Stereotactic Radiosurgery, American Society for Therapeutic Radiology and Oncology

PURPOSE

Although there is increasing interest in radiosurgery, little quantitative data regarding current patterns of radiosurgery practice are available. We developed a radiosurgery questionnaire to obtain information on radiosurgery practice.

METHODS AND MATERIALS

We distributed the questionnaire to the entire membership of the American Society of Therapeutic Radiology and Oncology in early 1993. Responses were obtained from 74 facilities that practice radiosurgery, corresponding to over 6000 treatments carried out since 1983 by 135 radiation oncologists and 130 physicists.

RESULTS

Most respondents were found to work within a multidisciplinary team, consisting of the following specialists (average hours devoted per patient on day of treatment in parentheses): radiation oncologist (3.8), neurosurgeon (3.2), physicist (6.1), radiologist (0.7), nurse (2.7), other (3.0). On average, neurosurgeons and nurses who perform Gamma Knife radiosurgery devote significantly more time-per-patient on the day of treatment than their peers who perform linac radiosurgery. On average, less experienced radiation oncologists and physicists (< or = 24 months experience, or < or = 50 patients treated) devote significantly more time-per-patient on the day of treatment than their more experienced peers. Although there are many more linac radiosurgery facilities than Gamma Knife facilities, on average the number of patients treated per month per facility is significantly larger at the latter. On average, follow-up responsibilities are nearly equally shared by radiation oncologists and neurosurgeons, except at Gamma Knife facilities, where neurosurgeons assume a larger percentage of follow-up responsibility. The percentages of patients treated at linac facilities for metastases or primary CNS malignancy are larger than the corresponding percentages at Gamma Knife facilities; the opposite is true for arteriovenous malformation, acoustic neuroma, and meningioma.

CONCLUSION

Current radiosurgery practice usually involves a team approach, with participation of specialists from radiation oncology, neurosurgery, physics, radiology, and nursing. The average number of M.D. and Ph.D. hours required per treatment on the day of radiosurgery is high.

Mechanical back pain and the facet joint syndrome

Mechanical back pain is a common disability often associated with the facet joint syndrome. Treatment is based on early, adequate pain relief with simple techniques of regional analgesia. In a few cases this is not enough and more sophisticated methods, such as radiofrequency denervation, cryo-analgesia and possibly intrathecal midazolam, are necessary. However, the main thrust of our approach is to treat the underlying structural disorder with strengthening of the back muscles and correction of postural abnormalities responsible for the mechanical back pain. Our report is based on an analysis of 83 patients who failed to respond to long periods of rest, suitable analgesic and allied drugs and other non-invasive measures. There had been no overriding indication for major surgery. A large number of these patients have been improved by our methods, but further work is in progress to extend the proportion of satisfactory results.

Neuropsychological abnormalities following CNS prophylaxis in children with acute lymphatic leukemia

The pattern and prevalence of neuropsychological abnormalities in children receiving combination CNS prophylaxis (2000 rads cranial irradiation and intrathecal methotrexate) during therapy for acute lymphoblastic leukemia (ALL) were studied. Thirty five children (25 boys) in the age group 5-15 years (mean 9.3) with no evidence of CNS leukemia were included and 20 age matched normal siblings served as controls. Neuropsychological parameters of general intelligence (Malin's modification of WISC test); attention and concentration (colour cancellation test); memory (modified PGI memory test) and visuomotor perception (Bender Gestalt test) were evaluated at least 6 months after CNS prophylaxis. Six (17.1%) patients had mean intelligence quotients (IQ) less than 85, while all controls had IQ > 85 (p < 0.05). The mean IQ of the patient population (93.4 +/- 11.9) was significantly lower than the control group (107 +/- 8.4) (p < 0.001). Scores on the colour cancellation test were lower in the patients as compared to controls (148.7 +/- 27.7 versus 184.9 +/- 23.9; p < 0.01). The mean memory quotient in the patient population was also lower than in controls (74.5 +/- 12 versus 93.6 +/- 9.2; p < 0.001). Scores on the Bender-Gestalt test did not show a significant difference. The presence of significant neuropsychological abnormalities in patients of ALL indicates the need for modification of the schedule of CNS prophylaxis. A comprehensive psychometric evaluation at regular intervals is essential for longterm rehabilitation.

Pharmacokinetic Evaluation of anti-HIV Drug Interactions: Effect of Zidovudine on 2′-3′-Dideoxyinosine Kinetics in Monkeys

The current investigation was conducted to determine if zidovudine (AZT) altered the pharmacokinetics of dideoxyinosine (ddl) in non-hurnan primates, an appropriate animal model for AZT and ddl pharmacokinetics in human. Each of nine animals received 20 mg kg−1of ddl intravenously in the absence and presence of two different dosage regimens of AZT. For each combination regimen, AZT was administered as a combined i.v. bolus-constant rate infusion regimen for 30 min that produced AZT plasma concentrations of about 4 μg ml−1in six animals (low dose group) and 11 μg ml−1in three others (high dose group). Serial blood samples were collected, and pharmacokinetic parameters for ddl were calculated based on plasma ddl concentrations measured by HPLC techniques.

The pharmacokinetics of ddl given alone in the first phase of the low ( n = 6) and high ( n = 6) dose AZT groups, resulted in a mean elimination half-life 1.54 and 1.9h, a mean total clearance of 0.62 and 0.731 h−1kg−1, and a mean steady state volume of distribution of 1.02 and 0.891 kg−1, respectively. Following combined ddl and AZT administrations, in both the low and high dose AZT groups, plasma concentration-time profiles of ddl were similar for each monkey, and no statistical differences were observed in the pharmacokinetic parameters compared to those obtained when ddl was given alone. The fact that AZT does not alter the pharmacokinetics of ddl at the range of AZT dose studied provides a basis for rational dosage design for combined ddl and AZT treatments in HIV infection.

Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database

Twenty-one arteriovenous malformations were prospectively evaluated using magnetic resonance angiography and compared with stereotactic angiography. The goals were to establish the feasibility of magnetic resonance angiography, compare it to stereotactic angiography, employ magnetic resonance angiography in follow-up, and semiquantify flow. A correlative evaluation between flow and response to stereotactic radiosurgery was carried out. Phase contrast angiograms were obtained at flow velocities of 400, 200, 100, 60, and 20 cm/sec. The fractionated velocities provided images that selectively demonstrated the arterial and venous components of the arteriovenous malformations. Qualitative assessment of the velocity within the arteriovenous malformations and the presence of fistulae were also determined by multiple velocity images. In addition, 3-dimensional time-of-flight magnetic resonance angiograms were obtained to define the exact size and shape of the nidus. This technique also permitted evaluation of the nidus and feeding arteries for the presence of low flow aneurysms. Correlation between the two imaging modalities was carried out by subjective and semiquantitative estimation of flow velocity and estimation of nidus size. The following velocity parameters were employed: fast, intermediate, slow, and none (arteriovenous malformation obliterated). In 19 of 21 (90.5%) arteriovenous malformations, magnetic resonance angiography was equal or superior to stereotactic angiography for flow quantification and visualization of the nidus. Only 2 of 21 arteriovenous malformations were better demonstrated by stereotactic angiography than by magnetic resonance angiography (failure rate of 9.5%). The nidus size in one case was clearly underestimated by stereotactic angiography and would have resulted in a geographic miss without magnetic resonance angiography. Seven post-radiosurgery arteriovenous malformations were evaluated for follow-up with both magnetic resonance angiography and stereotactic angiography. In 6 of 7 arteriovenous malformations, magnetic resonance angiography response matched stereotactic angiography response. Correlation of flow with outcome was carried out for 14 arteriovenous malformations using magnetic resonance angiography only. Interestingly, all nine arteriovenous malformations with intermediate or slow flow demonstrated partial or complete obliteration; whereas only 3 of 5 fast flow arteriovenous malformations achieved a response with a median follow-up of 10 months. This early analysis suggests that slower flowing arteriovenous malformations may obliterate faster after stereotactic radiosurgery and flow parameters could be employed to predict response. In conclusion, magnetic resonance angiography permits semiquantitative flow velocity assessment and may therefore be superior to stereotactic angiography. An additional advantage of magnetic resonance angiography is the generation of serial transverse images which can replace the conventional CT scan employed for stereotactic radiosurgery treatment planning.(ABSTRACT TRUNCATED AT 400 WORDS)

Pharmacokinetic evaluation of drug interactions with anti-human immunodeficiency virus drugs. VI. Effect of the calcium channel blocker nimodipine on zidovudine kinetics in monkeys

Coadministration of zidovudine (AZT) and nimodipine, a calcium-channel blocker, is a potential therapeutic regimen in acquired immunodeficiency syndrome patients based on the report that nimodipine can prevent human immunodeficiency virus-induced neurotoxicity in vitro. An evaluation of the pharmacokinetics of AZT and its glucuronide metabolite 3'-azido-3'-deoxy-5'-O-beta-D-glucopyranurosylthymidine (GAZT) in the presence and absence of nimodipine in monkeys was undertaken. After 20 mg/kg of AZT given i.v. in the presence and absence of nimodipine, nimodipine caused a significant reduction (41%) in the volume of distribution of AZT at steady state and a 22% decrease in total clearance. The disposition of GAZT was also influenced by nimodipine, causing a large increase in its area under the plasma concentration-time curve. Renal excretion data for AZT and GAZT, although inconclusive, suggested nimodipine caused a decrease in the renal clearance of AZT with a minimal change in the renal clearance of GAZT. The combined effects of nimodipine on the clearance of AZT and volume of distribution at steady state produced no change in its elimination half-life.

Comparison of the partition coefficient and skin penetration of a marine algal toxin (lyngbyatoxin A)

Lyngbyatoxin A is produced by marine algae, and causes local cutaneous toxicity in swimmers. The purpose of this research was (1) to determine the partition coefficient of lyngbyatoxin A in octanol/water and (2) to use methods in vitro to measure the penetration and distribution of lyngbyatoxin A in guinea pig and human skin. Discs of excised guinea pig and human skin were mounted in diffusion chambers that exposed the epidermal surface to air and bathed the dermis with HEPES-buffered Hanks' balanced salt solution with gentamicin sulphate. The epidermal surfaces were dosed with 26 micrograms lyngbyatoxin A/cm2 dissolved in 13 microliters dimethyl sulphoxide/cm2. The diffusion chambers were incubated at 36 degrees C for varying periods (1.0-24 hr). HPLC was used to quantify lyngbyatoxin A. Skin penetration was calculated by summing the amount of lyngbyatoxin A recovered from the dermis and receptor fluid. The mean partition coefficient for lyngbyatoxin A was 1.53. Penetration of lyngbyatoxin A (expressed as a percentage of dose, n = 3) in guinea pig and human skin was 23 and 6.2 (respectively) after 1 hr of topical exposure. The amount of lyngbyatoxin A in the dermis and receptor fluid did not change significantly over time.

Effect of vehicle on skin penetration and retention of a lipophilic red tide toxin (PbTx-3)

The purpose of this study was to determine the effect of carrier vehicle on the penetration of brevetoxin ([3H]PbTx-3) into skin layers and receptor fluid. Disks of guinea-pig skin were mounted on penetration chambers. Epidermal surfaces were dosed with 0.320 microgram/cm2 of PbTx-3 dissolved in 50 microliters of vehicle [water, methanol, or dimethylsulfoxide (DMSO)]. In vitro skin penetration by PbTx-3 during 24 hr of exposure was 6.2, 2.3 and 26% for water, methanol, and DMSO, respectively (expressed as % of dose applied).

Pharmacokinetic evaluation of drug interactions with anti-human immunodeficiency virus drugs. V. Effect of soluble CD4 on 2',3'-dideoxycytidine kinetics in monkeys

This study was conducted to determine if soluble CD4 (ST4) altered the pharmacokinetics of 2',3'-dideoxycytidine (ddC) in nonhuman primates. Each of six monkeys received 5 mg/kg of ddC iv in the absence and presence of two different iv regimens of ST4. The ST4 regimens produced steady-state plasma concentrations of 10.3 micrograms/ml (N = 3) and 22.2 micrograms/ml (N = 3) for 30 min following ddC administration. Pharmacokinetic parameters for ddC and ST4 were calculated based on plasma and urine concentrations of ddC and plasma concentrations of ST4. Following combined ddC and ST4 administration, in both the low- and high-dose ST4 groups, plasma concentration-time profile of ddC were similar for each monkey, and no statistical differences were observed in the pharmacokinetic parameters compared with those obtained when ddC was given alone. Complete urinary excretion data for ddC was obtained in 3 of the 6 animals studied. At the low ST4 dose, one animal had a reduced renal clearance of ddC, whereas at the high ST4 dose two animals recorded an increased renal clearance of ddC. ST4 plasma concentrations were comparable to in vitro concentrations of antiviral activity, with pharmacokinetic parameters similar to those reported previously. The kinetic information provides a basis for rational dosage design for combination chemotherapeutic regimens of ddC and ST4 in human immunodeficiency virus infection.