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Biomedical subjects

D Bateman

Publications and source records attributed to D Bateman.

16 recordsLinked to original sources

The internet.

The growing use of email and the world wide web (WWW), by the public, academics, and clinicians-as well as the increasing availability of high quality information on the WWW-make a working knowledge of the internet important. Although this article aims to enhance readers' existing use of the internet and medical resources on the WWW, it is also intelligible to someone unfamiliar with the internet. A web browser is one of the central pieces of software in modern computing: it is a window on the WWW, file transfer protocol sites, networked newsgroups, and your own computer's files. Effective use of the internet for professional purposes requires an understanding of the best strategies to search the WWW and the mechanisms for ensuring secure data transfer, as well as a compendium of online resources including journals, textbooks, medical portals, and sites providing high quality patient information. This article summarises these resources, available to incorporate into your web browser as downloadable "Favorites" or "Bookmarks" from www.jnnp.com, where there are also freely accessible hypertext links to the recommended sites.

Attitude to Computers↗

An MRI and neuropathological study of a case of fatal status epilepticus.

We report a case of fatal status epilepticus of unknown origin resulting in acute neuropathological changes in the hippocampus and claustrum. The case history, brain magnetic resonance images, and results of neuropathological study of the whole brain were obtained. The subject was a 35 year old male with no significant previous medical history who presented with generalized epileptic seizures progressing to status epilepticus. He died 6 days after developing status epilepticus. Magnetic resonance imaging (MRI) brain scans were performed before and four days after developing status epilepticus. The first scan was normal and the second showed high signal lesions on T2 weighted images in the medial aspects of both temporal lobes and in the right claustrum. Neuropathological studies showed severe neuronal loss in the Sommer section of both hippocampi with early glial reactive changes. Similar changes were seen in the claustrum on both sides. There was no evidence of other causes of brain injury such as infectious encephalitis or global hypoxic-ischaemic change. The patient died of status epilepticus for which no underlying cause was found despite extensive investigation. In this case the radiological and pathological changes found bilaterally in the claustrum and hippocampus appear to be the direct result of the status epilepticus.

Adult↗

Dose-response effect of fetal cocaine exposure on newborn neurologic function.

BACKGROUND: Studies of fetal cocaine exposure and newborn neurologic function have obtained conflicting results. Although some studies identify abnormalities, others find no differences between cocaine-exposed and cocaine-unexposed infants. To determine the effects of prenatal cocaine exposure on intrauterine growth and neurologic function in infants, we prospectively evaluated 253 infants shortly after birth. METHODS: Women who delivered a live singleton >36 weeks by dates were eligible for enrollment. Maternal exclusionary criteria were known parenteral drug use, alcoholism, and acquired immunodeficiency syndrome; infant exclusionary criteria were Apgar scores </=4 at 5 minutes, obvious congenital malformations, seizures, or strokes. A total of 98% of infants were evaluated between 1 to 7 days of age. Newborns were assessed with the Neurological Examination for Children (NEC) by a pediatric neurologist (C.A.C.) who was blinded to exposure status. Gestational age was determined by Ballard's examination. Cocaine exposure was determined for the last trimester by radioimmunoassay of maternal hair (RIAH). Exposure values ranged from 2 to 4457 ng/10 mg hair. Infants were excluded if a maternal hair sample was missing (N = 13). The sample comprises 240 woman and infant pairs-104 cocaine-exposed and 136 cocaine-unexposed. RESULTS: Compared with unexposed controls, cocaine-exposed infants exhibited higher rates of intrauterine growth retardation (24% vs 8%), small head circumference ([HC] <10th% percentile) (20% vs 5%) and neurologic abnormalities: global hypertonia (32% vs 11%), coarse tremor (40% vs 15%), and extensor leg posture (20% vs 4%). We found increasing odds (odds ratio) of growth and neurologic impairment with increasing level of cocaine exposure in stratified analyses. The odds ratio associated with three levels of cocaine exposure (no exposure, low exposure = RIAH 2-66 ng/mg; and high exposure = RIAH 81-4457 ng/mg) respectively are: 1.0, 3.3, and 6.1 for small head size (chi2 for trend); 1.0, 3. 3, and 4.3 for global hypertonia (chi2 for trend); 1.0, 3.4, and 7.4 for extensor leg posturing (chi2 for trend); and 1.0, 3.8, and 3.8 for coarse tremor (chi2 for trend). Significant associations between cocaine exposure and neurologic signs were found in logistic regression equations that controlled for 20 or more variables. CONCLUSION: We conclude that adverse neonatal effects associated with fetal cocaine exposure follow a dose-response relationship: newborns with higher levels of prenatal cocaine exposure show higher rates of impairments in fetal head growth and abnormalities of muscle tone, movements, and posture. Significant relationships between cocaine exposure and these outcomes remain in controlled analyses.

Adult↗

Left ventricular thrombi in a patient with the antiphospholipid syndrome.

A 41 year old woman with the antiphospholipid antibody syndrome presented with a cerebral embolus. This was caused by a mobile left ventricular thrombus that later resolved. There was an additional old left ventricular thrombus. Left ventricular thrombi such as these have not been previously described in this syndrome, and may have been under diagnosed.

Adult↗

Mutation analysis in patients with possible but apparently sporadic Huntington's disease.

Until the advent of mutation analysis it was impossible to make a certain diagnosis of Huntington's disease (HD) in the absence of a positive family history, and sporadic cases of possible HD presented a substantial diagnostic dilemma. We have looked for the characteristic expanded trinucleotide (CAG) repeat sequence in the HD gene in 44 patients with probable or possible HD who did not have similarly affected relatives. We used two methods, the traditional widely used method, which estimates both the CAG repeat and the flanking CCG repeat and gives the CAG length by subtraction, and the more precise CAG method, which estimates the repeat length directly. With the CAG method, the HD mutation was detected in 25 (89%) of 28 patients with the typical clinical features of HD and 5 (31%) of 16 in whom the diagnosis was more doubtful. The CAG-CCG method gave results in the borderline abnormal range of repeats for 13 of the 33 patients eventually shown to have an unequivocal repeat expansion by the CAG method. Most of these patients had late onset of symptoms. There was evidence of expansion of an intermediate-length paternal allele in 1 patient and of non-paternity in another. The identification of the mutation causing HD means that it is now possible to confirm or exclude the diagnosis with confidence, even in the absence of a family history, by analysis of DNA from a blood sample. The precise method of measuring the CAG repeat, which is technically more difficult than the traditional method, may be needed to clarify results in a substantial proportion of such patients.

Adult↗

A follow-up study of isolated cases of suspected Huntington's disease.

We reviewed 49 patients in whom a diagnosis of Huntington's disease (HD) seemed possible on clinical grounds, but who gave no history of definitely affected relatives. In 32 with the typical clinical features of HD (progressive chorea and dementia, postural instability, abnormal initiation of saccadic eye movements), the diagnosis was confirmed in 7 patients who had had autopsies, affected relatives were found in 5 others, and HD remained probable in a further 13 who were reexamined. In the 17 with a less typical clinical picture, a diagnosis of HD appeared most likely in 2; other causes for chorea such as cerebrovascular disease, neuroacanthocytosis, recrudescence of Sydenham's chorea, and drug-induced tardive dyskinesia could be invoked in the remainder. We conclude that the likelihood of HD in a patient with the typical clinical features of this disorder but no history of affected relatives is at least 75%, which for practical purposes implies a risk to their children hardly less than in familial HD. The most plausible explanations for seemingly sporadic patients with HD are nonpaternity and mild, late-onset disease that is overlooked by other family members.

Adult↗

A method of studying pharmacokinetics in man at picomolar drug concentrations.

1. We describe a new method that enables the tissue kinetics of picomolar concentrations of drugs to be measured in man. The method is based on the administration of a drug, labelled with a short-lived positron-emitting radioisotope, such as carbon-11 (t1/2 = 20.4 min, beta + = 99.8%) or fluorine-18 (t1/2 = 109.8 min, beta + = 96.9%), which is then detected in vivo by an array of 10 large uncollimated sodium iodide scintillation detectors, arranged as five opposing pairs, with each pair collecting data over one major organ or region of the body. 2. To illustrate the scope of the new method we report the results of administering [O-methyl-11C]-diprenorphine, an established radioligand for central opiate (mu, kappa, and delta) receptors and L-6-[18F]-fluoro-DOPA, a marker for dopaminergic neurons. 3. Only 2-10 muCi (74-370 kBq) of radioactivity are used and, as a consequence of the high specific activities with which carbon-11 and fluorine-18 labelled compounds can be prepared, the method requires less than a nanomole of drug to be administered. In many cases, this amount of drug might be considered low enough to avoid any adverse biological effect. Furthermore repeat studies are possible in many without delivering unacceptable radiation burdens. 4. The high sensitivity realised for both radioactivity and mass suggests a mean for determining the human biodistribution of a new drug at a very early stage in its development. This has potential benefit to drug discovery programmes and to ensuing drug therapies.

Blood-Brain Barrier↗

Infant morbidity in Harlem: a status report.

To the longstanding cycle of poverty, disease, and despair that has afflicted several generations of Harlem residents have now been added epidemics of crack abuse, AIDS, syphilis, and pervasive violence. The community's children have been especially vulnerable to these calamities. Harlem's traditional institutions of strength, aid, and comfort--its extended families, churches, the hospital, and the government--have become nearly overwhelmed by mounting social disorganization and an apparent lack of resources. It may be possible to combat such problems by re-examining some of the assumptions we have used to deal with them, by energetically addressing their more manageable components, and by greatly increasing support for viable community institutions such as the public hospital. At the same time, we will need to learn many more facts about crack, AIDS, poverty, and shattered families so that, whenever possible, our efforts will be informed and our choices intelligent.

Acquired Immunodeficiency Syndrome↗

Focal retrograde amnesia: a long term clinical and neuropsychological follow-up.

A patient (E.D.) who had displayed a selective retrograde amnesia in association with transient amnesic episodes (Kapur et al., 1986) was reexamined five years after initial assessment. At the clinical level, his transient amnesic attacks continued, but some of these had clear epileptic features. In addition, EEG investigation indicated temporal lobe abnormality, more prominent in the left temporal region, and supported a clinical diagnosis of temporal lobe epilepsy. Both CT scanning and magnetic resonance imaging were unable to detect the presence of any structural lesion. At the neuropsychological level, there was no evidence of dementia in the form of generalized cognitive dysfunction nor significant deterioration in cognitive functioning since the earlier assessment. Our patient continued to show marked memory loss for public events over the past 20-30 years, in the context of normal or near normal performance on most tests of anterograde memory functioning. While memory for famous scenes and famous faces was markedly impaired, our patient's memory for famous cars was within normal limits and his memory for autobiographical events showed only patchy impairment. Although E.D. performed at an average or above average level on most standard tests of anterograde memory functioning, our patient did show evidence of significant memory loss for public events which had occurred over the past ten years (i.e. since the onset of his illness). The possibility is raised that E.D.'s memory disorder may represent a form of disconnection syndrome.

Aged↗

The effect of raised intracranial pressure on intracochlear fluid pressure: three case studies.

The effects of changes in intracranial fluid pressure (ICP) on cochlear fluid pressure have been studied in 3 patients who underwent ventriculo/lumbar-peritoneal shunt operations. The operations were performed in order to alleviate problems caused by an abnormally raised ICP. Indirect measurements of perilymphatic pressure were made before and after surgery using a non-invasive technique which measures tympanic membrane displacement. This technique proved extremely sensitive and revealed changes in cochlear fluid pressure brought about by changes in the ICP. The results emphasise the need to consider audiological measurements in the context of ICP abnormalities. These findings have important implications in that an audiological technique may be used for the simple and non-invasive serial monitoring of changes in ICP and may even assist differential diagnosis in a number of neurological patients.

Adolescent↗

A scoring system for states of sleep and wakefulness in term and preterm infants.

We designed and validated a system for determining the state of sleep or wakefulness in both term and preterm infants. The system is based on independent assessments of behavioral and electroencephalographic (EEG) patterns. Overall agreement between observers in coding individual behavioral patterns was 77.6%. Agreement between observers in coding EEG patterns was 87.4%. Designation of an infant's state is made by combining concurrent behavioral and EEG scores into a single two-number code. The distribution of sleep state for eight infants greater than 36 wk postconceptional age (PCA) was the following: quiet sleep (QS), 30.4%; active sleep (AS), 50.0%; indeterminate sleep (IS), 11.4%, and wakefulness (W), 7.5%. The distribution of sleep state for 15 infants less than 36 wk PCA was as follows: QS, 18.9%; AS, 52.9%; IS, 16.4%; and W, 10.5%. Our experience with the system suggests that it is useful for relating sleep state to physiologic variables during neonatal experimental studies.

Child Behavior↗

Spontaneous variability in minute ventilation oxygen consumption and heart rate of low birth weight infants.

Continuous measurements of minute ventilation (VI), oxygen consumption (VO2), heart rate (HR), activity, and temperature were made in eleven low birth weight infants during the interval between feedings. Significant increases in VI, VO2, and HR were noted between quiet and active sleep. (VI Active - VI Quiet/VI Quiet) X 100 = 18.4% VO2 Active - VO2 Quiet/VO2 Quiet) X 100 = 10.1% and HR Active - HR Quiet/HR Quiet) X 100 = 6.4%. Significant differences were also noted within epochs of the same state of sleep: mean slope VI versus time in epoch (t) = -156 ml/kg . min/hr, VO2 versus t. = 1.49 ml/kg . min/hr and HR versus t = -15.0 beats/min/hr. Differences between successive epochs of the same state of sleep were also observed: VI, +5.9 to 46.6%; VO2, 4.7 to 24.6%; HR, 1.0 to 9.7%. These differences were related to the length of time after feeding. These data indicate that steady state conditions do not occur in growing low birth weight infants and that the design of studies of respiration and metabolism in these infants should include continuous assessment of the state of sleep or activity and time after feeding to ensure that experimental and control periods are truly comparable.

Heart Rate↗

Red cell sodium in hyperthyroidism.

A simple method of measuring red cell sodium has shown that about 90% of thyrotoxic patients have values above the upper limit of the normal range. Patients taking 0.3 mg of L-thyroxine daily were found to have a significantly higher mean value for red cell sodium than that of the normal controls. It is suggested that patients taking this amount of thyroxine may be hypermetabolic. The determination of red cell sodium may prove useful as a measure of the peripheral action of thyroid hormone.

Adult↗