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Biomedical subjects

P Wade

Publications and source records attributed to P Wade.

18 recordsLinked to original sources
PubMed2000

A case of Balamuthia mandrillaris meningoencephalitis.

Balamuthia mandrillaris is a newly described pathogen that causes granulomatous amebic encephalitis, an extremely rare clinical entity that usually occurs in immunosuppressed individuals. We report a case of pathologically proven Balamuthia encephalitis with unusual laboratory and radiologic findings. A 52-year-old woman with idiopathic seizures and a 2-year history of chronic neutropenia of unknown cause had a subacute illness with progressive lethargy, headaches, and coma and died 3 months after the onset of symptoms. Cerebrospinal fluid (CSF) glucose concentrations were extremely low or unmeasurable, a feature not previously described (to our knowledge). Cranial magnetic resonance imaging scans showed a single large temporal lobe nodule, followed 6 weeks later by the appearance of 18 ring-enhancing lesions in the cerebral hemispheres that disappeared after treatment with antibiotics and high-dose corticosteroids. The initial brain biopsy specimen and analysis of CSF samples did not demonstate amebae, but a second biopsy specimen and the postmortem pathologic examination showed Balamuthia trophozoites surrounded by widespread granulomatous inflammation and vasculitis. The patient's neutropenia and antibiotic use may have caused susceptibility to this organism. Amebic meningoencephalitis should be considered in cases of subacute meningoencephalitis with greatly depressed CSF glucose concentrations and multiple nodular lesions on cerebral imaging. Arch Neurol. 2000;57:1210-1212

Amebiasis↗
PubMed1999

Characterization of a chromatin remodelling activity in Xenopus oocytes.

The yeast SWI2/SNF2 protein is a component of a large protein complex which is involved in the remodelling of chromatin during transcriptional activation. Several homologous complexes have been found in Drosophila and mammals. We have examined the expression of the SWI2/SNF2 homologue BRG1 in Xenopus laevis using two antisera originally raised against the C-terminus of the rat and the human BRG1 protein. These two antisera cross-reacted with a protein found in both Xenopus liver and Xenopus oocytes. The Xenopus BRG1-like protein is expressed throughout oogenesis (stages I-VI) and embryogenesis. By injecting an expression vector containing the full-length human BRG1 cDNA into Xenopus oocytes, the relative molecular weight (Mr) of the Xenopus BRG1-like protein was shown to be slightly lower than that of the human BRG1, 190 000 and 200 000, respectively. The Xenopus BRG1-like protein elutes at a Mr of approximately 2 000 000 on Superose HR6trade mark size-exclusion chromatography, indicating that it is part of a larger complex, as are all other known SWI/SNF proteins. Nucleosome remodelling activity was co-eluted with the BRG1 immunogenic activity in both ion-exchange and size-exclusion chromatography.

Animals↗
PubMed1998

Kinetics and toxicity of liposomal and conventional amikacin in a patient with multidrug-resistant tuberculosis.

The pharmacokinetics and toxicity of liposomal amikacin in a patient treated for advanced pulmonary multidrug-resistant tuberculosis are described. A dose of 20 mg/kg of liposomal amikacin was given on alternate days for 14 days and weekly thereafter for 9 weeks, for a total dose of 20.1 g in 17 divided doses. Accumulation occurred with alternate-day, but not weekly, dosing. The serum levels of amikacin obtained with the liposomal preparation were considerably greater than those obtained with the conventional preparation (range, 81-457 mg/l vs. 4.1-37.7 mg/l). The liposomal amikacin was well tolerated and led to clinical improvement, but it failed to achieve a microbiological response. The patient's sputum remained smear- and culture-positive during the treatment period with liposomal amikacin and for 9 months afterward.

Aged↗
PubMed1998

Imaging the problem scaphoid.

Scaphoid fractures can be difficult to diagnose on X-ray, even at 2 weeks. We have compared prospectively bone scanning versus MRI scanning in 22 patients with persistent signs and symptoms suggestive of a scaphoid fracture at 2 weeks and found both methods to be sensitive, but MRI to be more specific, particularly in diagnosing soft tissue injuries like scapho-lunate ligament ruptures and triangular fibrocartilage tears. An early MRI scan at 2 weeks allows the clinician to make the appropriate decision in this group of patients whose diagnoses include; occult scaphoid fractures, other occult carpal and radial fractures, ligamentous injuries and those without apparent injuries. MRI has also been useful in defining the group of injuries which may imitate a clinically occult scaphoid fracture.

Adolescent↗
PubMed1994

Nurse practitioners, certified nurse midwives, and nurse anesthetists: changing care in acute care hospitals in New York City.

To respond to the shrinking pool of primary care physicians and to demands from managed care programs for cost containment, hospitals in New York City have increased their use of nurse practitioners, certified nurse midwives, and nurse anesthetists, creating an increased demand for these personnel. We report here on a survey of hospitals and schools of nursing in New York City and present findings on (a) current use of, and projected demand for nurse practitioners (NPs), certified nurse midwives (midwives) and nurse anesthetists (anesthetists) in hospitals in New York City; (b) the practice patterns of NPs, midwives, and anesthetists currently employed in hospitals; and (c) current and projected enrollment and curriculum in NP, midwifery, and anesthetist education programs in the New York metropolitan area.

Adult↗
PubMed1987

Promyelocyte morphology. Differentiation of acute promyelocytic leukemia from benign myeloid proliferations.

Bone marrow aspirates from patients with acute agranulocytosis or a marked left shift in myeloid maturation can mimic acute leukemia, particularly acute hypergranular promyelocytic leukemia. Bone marrow aspirates from 16 cases of apparent acute promyelocytic leukemia, 4 cases of acute agranulocytosis, and 1 case of a marked myeloid left shift were studied for the presence or absence of differentiating features. Normal or reactive promyelocytes were characterized by prominent paranuclear clear Golgi zones, whereas promyelocytes from true leukemic cases all had heavy azurophilic granules dispersed diffusely throughout the cytoplasm. Prominent Golgi zones in promyelocytes were associated only with benign myeloid conditions and were not observed in acute promyelocytic leukemia. The presence of prominent clear Golgi zones in promyelocytes is an important feature assisting in the distinction between leukemic and benign promyelocytes.

Adult↗
PubMed1983

Benzodiazepines impair smooth pursuit eye movements.

Five healthy male volunteers received single oral doses of 10 mg diazepam, 20 mg temazepam and placebo, in a double-blind, randomised fashion. Smooth pursuit eye movement velocity and serum benzodiazepine concentration were measured before and after at 0.5,1,1.5,2,3,4,6,9 and 12 h after administration of the treatments. Significant decrease in smooth pursuit eye movement velocity as compared to placebo was observed between 0.5-2 h after temazepam, and between 1-2 h after diazepam. Smooth pursuit eye movement velocity was log-linearly correlated with serum temazepam and diazepam concentration. The results demonstrate the relationship between serum benzodiazepine concentration and its effect on an objective measure of oculomotor performance.

Adult↗
PubMed1982

A normative study of postural tremor of the hand.

In a normative study of amplitude, frequency, and variability of postural tremor of the hand in 97 normal subjects, 15 to 80 years old, tremor was transduced using accelerometers and characterized by power spectral analysis. Tremor amplitude ranged from a 0.0015- to 0.035-g peak at the dominant frequency. The modal tremor amplitude was 0.01-g peak, and the threshold for "visible tremor" was 0.007-g peak. The modal tremor frequency was constant at about 7 Hz in those subjects up to 70 years old and thereafter decreased to about 6 Hz. The mean range of variability of the dominant frequency was 2.5 Hz. The tremor pattern, characterized by the shape of spectra, varied greatly from a single finely tuned peak to multiple broad peaks. More than two thirds of normal subjects showed complex spectral patterns with more than one peak of significance. Passive resonance of the hand tissues was an important factor in determining dominant tremor frequencies in most subjects. Many subjects showed a strong, albeit variable , cardioballistic component. The results provide baseline data for studies of the effects of drugs on tremor, particularly in cases of "essential" tremor, and provide warnings that such studies require objective recording methods for adequate evaluation and need recourse to measurement of several factors of the tremor to elucidate the component of tremor affected by a drug. A scaling of tremor can be used in terms of reference to the strength of gravitational acceleration (1.0 g), which provides simple numerical relationships.

Adolescent↗
PubMed1982

Loudness adaptation: real or illusory.

There is general agreement that, except at low sensation levels, the loudness of a continuous pure tone does not appear to change with time. By contrast, using a simultaneous dichotic loudness balancing procedure (SDLB) a substantial fall in loudness can be revealed. As a result it has been held that the latter does not represent a loudness loss in real terms but is a manifestation of some form of central binaural interaction possibly involving localization mechanisms. In two studies reported here, one involving a loudness scaling procedure using as a standard a reference tone of 65 dB (HL) and the other a loudness doubling procedure, a loudness loss has been clearly demonstrated following sustained stimulation with a continuous 60-dB (HL), 1000-Hz tone applied monaurally. The progression of the loudness loss with time follows a similar course to that found with the SDLB procedure. In consequence it is concluded that both represent a loudness loss in real terms and that inability to detect a change in loudness over time of a continuous tone results from the absence of any reference standard by which it can be judged.

Acoustic Stimulation↗
PubMed1981

The relationship between peak velocity of saccadic eye movements and serum benzodiazepine concentration.

1 Six healthy male volunteers received single oral doses of 10 mg diazepam, 20 mg temazepam, 15 mg flurazepam, 5 mg nitrazepam, 10 mg desmethyl-diazepam and placebo in a double-blind randomized fashion. 2 Peak velocity of saccadic eye movements, serum benzodiazepine concentration, and subjective ratings of wakefulness and co-ordination were measured at intervals up to 12 h after drug administration. 3 All active treatments produced a statistically significant decrease in peak saccadic velocity. The effect of temazepam and diazepam was generally more pronounced than that of flurazepam, nitrazepam and desmethyl-diazepam. 4 There were log-linear correlations between peak saccadic velocity and serum benzodiazepine concentration after ingestion of temazepam, diazepam and nitrazepam. 5 These results demonstrate a clear relationship between serum benzodiazepine concentration and its effect on a convenient measure of brainstem reticular formation function.

Adult↗
PubMed1980

Mechanism of rotatory eye movements in opsoclonus.

'Rotatory nystagmus', in which the visual axis of the eye moves involuntarily in the horizontal and vertical planes describing a closed loop trajectory, was analysed by means of combined video and electro-oculography in a patient with multiple sclerosis having numerous ocular signs of cerebellar disease. The rotations were sporadic, isolated single cycles having stereotyped, crescentiform loop shapes. Each consisted of a combination of a single cycle of vertical ocular flutter, the onset of which was followed 40 to 50 milliseconds later by a single cycle of horizontal ocular flutter. The timing relationship between flutters suggest that the vertical and horizontal systems had become somehow entrained. Rotatory nystagmus is saccadic in nature and arises from a unique timing relationship between vertical and horizontal flutter.

Adult↗