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Biomedical subjects

R Howard

Publications and source records attributed to R Howard.

At least 109 records · Page 6Linked to original sources
PubMed1996

Detection of coccidioidal antibodies by 33-kDa spherule antigen, Coccidioides EIA, and standard serologic tests in sera from patients evaluated for coccidioidomycosis.

During a 9-month study of patients being evaluated for coccidioidomycosis, 1 or more serum samples were obtained from 138 patients with an illness suggestive of recent infection. In this group, standard immunodiffusion tests of unconcentrated sera were positive for 25; 49 additional patients had at least 1 reactive test result by newer enzyme-linked serologic tests. At least 11 of these 49 patients had coccidioidomycosis as determined by culture or subsequent standard serologic tests. Patients with coccidioidomycosis identified only by newer tests had fewer or milder clinical abnormalities than did patients in whom the disease was detected by standard tests. For 31 other patients with illness of a chronic or undetermined duration, newer tests detected only 10 more than the 18 identified by standard tests, suggesting that later in the course of illness, standard testing gains in sensitivity for coccidioidal infection.

Antibodies, Fungal↗
PubMed1996

A comparison of the induction characteristics of sevoflurane and halothane in children.

The induction characteristics of sevoflurane and halothane were compared in 81 children aged 6 months to 6 years. The mean time taken to achieve loss of eyelash reflex was significantly shorter with sevoflurane than with halothane (sevoflurane, mean time (SD) 1 min 41 s (35 s), halothane, mean time (SD) 2 min 17 s (43 s), t = 4.11, p = < 0.01). The mean time taken to complete induction (to achieve steady spontaneous ventilation and small pupils with central gaze) was also shorter in children induced with sevoflurane (sevoflurane, mean time (SD) 3 min 58 s (1 min 8 s), halothane, mean time (SD) 4 min 50 s, (1 min 27 s), t = 2.29, p = 0.027). Effects on heart rate, blood pressure and oxygen saturation during induction were similar for both agents. There were no major complications during induction with either halothane or sevoflurane.

Anesthesia, Inhalation↗
PubMed1996

A comparison of the recovery characteristics of sevoflurane and halothane in children.

The recovery characteristics of sevoflurane and halothane anaesthesia were compared in 40 children aged 6 months to 6 years undergoing day case surgery. The mean time taken to open eyes after surgery had ended was appreciably and significantly shorter after sevoflurane than after halothane (sevoflurane, mean time (SD) 7 min 52 s (5 min 46 s), halothane, mean time (SD) 15 min 50 s (9 min 2 s), t = 3.32, p = 0.002). The time taken to be ready for discharge from the recovery unit to the ward was also significantly shorter after sevoflurane than after halothane (sevoflurane, mean time (SD) 12 min 46 s (4 min 11 s), halothane, mean time (SD) 19 min 13 s (9 min 48 s), t = 2.7, p < 0.01). However, more children were in pain and given analgesia after sevoflurane (p < 0.01) and the mean time to reach the criteria for discharge home was similar in both groups (sevoflurane, mean time (SD) 2 h 9 min (17 min), halothane, mean time (SD) 2 h 4 min (8 min)). There were no major complications in either group.

Ambulatory Surgical Procedures↗
PubMed1996

Identification of mutations in the Ki-ras gene in human retinoblastoma.

PURPOSE: To investigate the mutational status of the Ki-ras gene in retinoblastoma and to evaluate a correlation of the genotype with clinical and histopathologic variables. METHODS: Tumor samples were microdissected from sectioned archival paraffin-embedded tissue. Ki-ras genomic sequences (exons 1 and 2) were amplified by polymerase chain reaction then analyzed by single-strand conformation polymorphism and direct sequencing. Tissue sections, flanking the analyzed samples, were stained with hematoxylin and eosin for examination by light microscopy. RESULTS: Four of 12 tumors had mutation in exon 1, codon 12 of the Ki-ras gene; none had mutation in exon 2. Signal intensity of the mutated alleles indicates clonal mutation in the tumor cell populations. One of four bilateral tumors was mutated, and all three samples with undifferentiated histologic appearance harbored a clonal Ki-ras mutation. However, only one of nine moderately to poorly differentiated tumors harbored a mutation. CONCLUSIONS: Ki-ras, an oncogene seldom altered in neuroectodermal neoplasms, is mutated in one third of the retinoblastomas studied. The Ki-ras mutations are clonal, suggesting that affected cells have a selective growth advantage. The mutations are present and are likely to play a pathogenetic role in heritable and sporadic retinoblastomas. These results suggest that mutations in Ki-ras are preferentially associated with undifferentiated tumors.

Adolescent↗
PubMed1995

White matter signal hyperintensities in the brains of patients with late paraphrenia and the normal, community-living elderly.

We determined the prevalence and anatomical location of areas of white matter hyperintensity visualized by magnetic resonance imaging in the brains of 38 late paraphrenic patients with an onset of psychotic illness after the age of 60 and 31 healthy aged community volunteers. All degrees of white matter signal hyperintensity were very common in both groups, and there was no excess of such changes in the brain of patients. Periventricular white matter and subcortical grey matter hyperintensities were significantly associated with both measured diastolic and systolic blood pressure in patients and control subjects. Periventricular and deep white matter, together with subcortical grey matter hyperintensities, were significantly associated with increased age. The excess of such presumed brain-imaging abnormalities previously reported in patients with an onset of psychosis late in life may be a consequence of earlier authors' failure to include examination of appropriate community control populations and to carefully exclude patients with evidence of stroke.

Aged↗
PubMed1995

Increasing age is a risk factor for psychosis in the elderly.

We examined the association between ageing and the administrative incidence rate of late onset (after age 59) non-organic, non-affective psychosis in two samples of patients aged 60 years or older who were first admitted to hospital in (1) The Netherlands between 1978 and 1992 (n = 8010) and (2) nine regional health authorities in England and Wales (n = 1777) between 1976 and 1978. There was a linear trend in the association between increasing age and first admission rates for non-organic, non-affective psychosis in the elderly, after adjustment for the possible confounding effects of time trend and gender, corresponding to an 11% increase in the incidence with each 5-year increase in age. These observations support a connection between degenerative brain processes and onset of non-affective psychosis in the elderly.

Aged↗
PubMed1995

Tinea capitis: new perspectives on an old disease.

Tinea capitis caused by Trichophyton tonsurans is a common infection in children, and has become a significant public health problem in the United States. Epidemics of tinea capitis occur both in families and in institutions such as schools and day care centers. Infection is often difficult to eradicate. Fomites and asymptomatic carriers likely contribute to the spread of the disease and to re-infection of treated patients. The morphology of tinea capitis is diverse, from seborrhea-like scaling to tender, inflammed nodules on the scalp. Because a lengthy course of systemic griseofulvin is required to treat this infection, management of tinea capitis can be challenging. As newer antifungal agents are developed, more effective and convenient therapy for tinea capitis may become available.

Adult↗
PubMed1995

Magnetic resonance imaging volumetric measurements of the superior temporal gyrus, hippocampus, parahippocampal gyrus, frontal and temporal lobes in late paraphrenia.

Quantified magnetic resonance measurements were made of superior temporal gyrus, parahippocampal gyrus, hippocampal, frontal and temporal lobe volumes and of the planar area of the thalamus and basal ganglia structures in 47 late paraphrenic patients and 33 healthy elderly controls. The late paraphrenics were divided into 31 schizophrenics and 16 patients with delusional disorder according to ICD-10 guidelines. Patients with delusional disorder tended to have smaller left temporal volumes compared with control subjects and patients with schizophrenia, but this difference failed to reach accepted levels of statistical significance after correction for the effects of multiple statistical comparisons, age and total brain size. Physiological right-left asymmetry, reported for temporal and frontal lobe volumes, was present in control, schizophrenic and delusional disorder subjects but delusional disorder patients had a significantly greater degree of temporal lobe asymmetry. The results add to the evidence for heterogeneity among late-onset psychoses and emphasize the subtle nature of any structural brain abnormalities in these patients.

Aged↗
PubMed1995

Treatment-resistant depression in the elderly.

Apparent treatment-resistant depression (TRD) is frequently encountered by and poses particular challenges for the old-age psychiatrist. The prevalence of true nonresponse to treatment is not known with accuracy but reports put it at 18% to 40% for the elderly. This article reviews the concept of TRD in the elderly, discussing the factors involved in apparent resistance and the treatment of this group. We suggest that absolute TRD may be a rarer entity than the estimated 18% to 40% if depressed patients are treated carefully and vigorously.

Aged↗
PubMed1995

Impact of childhood cancer on siblings and family: family strategies for primary health care.

The article reviews the impact of a chronic illness with a potentially life-threatening outcome on siblings and suggests strategies to enhance sibling support by an advanced practice nurse. The well siblings in the family system have the potential to perceive threatened or actual losses as a result of their brother's or sister's illness. The importance of considering total family structure, including the sibling's emotional needs, in an ongoing assessment to determine strengths, vulnerabilities, and coping abilities is presented. The advanced practice nurse in an ambulatory care setting, community setting, or hospital is in a unique position to provide comprehensive guidance and coordination of mechanisms of support in concert with the family in an effort to reduce vulnerability and to maintain the emotional well-being of the siblings.

Adaptation, Psychological↗
PubMed1995

Down's syndrome and anaesthesia.

Down's syndrome is a common congenital abnormality associated with characteristic morphological features, impaired intellectual development and disorders of many organ systems with a broad spectrum of severity. Many of these, including defects in cosmetic appearance, are amenable to surgical correction. The risks of anaesthesia are increased in these children. In this article the anaesthetic implications of the syndrome are reviewed and the principles of perioperative management discussed.

Anesthesia↗
PubMed1995

Fear conditioning, preparedness, and the contingent negative variation.

Psychophysiological research on preparedness has previously focused on autonomic nervous system parameters. The present study used electrocortical indices of fear conditioning. Subjects (n = 10) were tested under fear-relevant and fear-irrelevant conditions (1 week apart, order of conditions counterbalanced). Each condition comprised acquisition and extinction sessions. The contingent negative variation (CNV) was elicited in anticipation of forewarned slides (fear relevant: small animals; fear irrelevant: landscapes). In acquisition, reinforced conditioned stimulus (CS+) (but not nonreinforced conditioned stimulus [CS-]) slides were followed by white noise as an unconditioned stimulus (UCS). In extinction, the UCS was omitted. In the fear-relevant condition, CNV amplitude was significantly larger for CS+ than CS- in both acquisition and extinction. In the fear-relevant condition, CNV amplitude was significantly larger for CS+ than CS- in both acquisition and extinction. In the fear-irrelevant condition, CNV differentiation between CS+ and CS- was weak in both sessions. CNV was significantly larger in the fear-relevant than in the fear-irrelevant condition, for CS+ but not CS-. The findings are consistent with a preparedness interpretation and suggest that CNV under such circumstances may represent an automatic affective response to fear-relevant stimuli. Electrocortical measures could be particularly useful in examining information processing mechanisms in phobia and cognition-affect relationships generally.

Adolescent↗
PubMed1995

Comparative evaluation of a commercial enzyme immunoassay for the detection of human antibody to Rickettsia typhi.

A commercial enzyme immunoassay kit called the Dip-S-Ticks (DS) for the detection of total immunoglobulin (Ig) G and IgM human antibodies to Rickettsia typhi was evaluated. In tests with 340 serum samples from patients with diagnosed cases of rickettsial diseases, patients suffering from other febrile illnesses, and normal subjects, the DS compared favorably with the standard indirect fluorescent-antibody (IFA) test. At IFA cutoff titers of > or = 1.64 and > or = 1:128, the DS showed sensitivities of 88.2 and 91.4% and specificities of 91.8 and 87.7%, respectively. The DS test correlated significantly with both the IFA IgG (r = 0.84, P < 0.0005) and IgM (r = 0.63, P < 0.0005) titers. Only 80% of IgG and 82% of IgM IFA readings determined by two technicians were within one dilution, while the DS was more reliable, with 100% within one dot. The rapidity, reliability, and simplicity of the DS suggest that it is a suitable test for use in clinical laboratories unable to perform the IFA test.

Antibodies, Bacterial↗
PubMed1994

Tinea capitis: epidemiology, diagnosis, treatment, and control.

Since the 1970s there has been a steady rise in the number of cases of tinea capitis in the United States, most of them caused by Trichophyton tonsurans. Although the infection is seen most frequently in black children, it can occur in white persons and can affect persons of all ages. Control of tinea capitis is difficult for several reasons, including subtle clinical infection, asymptomatic carriage of fungus, fomite spread, and the need for weeks to months of oral medications. Although griseofulvin remains the mainstay of therapy, preliminary studies of itraconazole and terbinafine suggest that these compounds may also be useful in the treatment of tinea capitis. Selenium sulfide shampoo, prednisone, and oral antibiotics are frequently used as adjunctive therapy. The role of fomites in the spread of tinea capitis has yet to be fully understood, as does the best means of decontamination.

Adolescent↗
PubMed1994

Phenomenology, demography and diagnosis in late paraphrenia.

One hundred and one patients with late paraphrenia were examined using the Present State Examination. The established high prevalence rates of female gender, the unmarried state and sensory impairment were confirmed. All of the symptoms of schizophrenia, with the exception of formal thought disorder, were found in the subjects with approximately the same prevalence as reported in schizophrenics with a symptom onset in younger life. The presence of visual hallucinosis was significantly associated with visual impairment, but the same association was not found between auditory hallucinations and deafness. Mean age at onset of symptoms was high at 74.1 years. Using ICD-10 diagnostic criteria the patients were categorized as schizophrenia (61.4%), delusional disorder (30.7%) and schizoaffective disorder (7.9%). Patients in these diagnostic categories differed in their pre-morbid IQ estimations, current cognitive state measured by the Mini-Mental State Examination and in the number of scored positive psychotic PSE symptoms and their systematization of and preoccupation with delusions and hallucinations. There were no significant differences between the patients in the ICD-10 schizophrenia and delusional disorder groups in terms of age at symptom onset, sex ratio, response to treatment, being unmarried, the presence of insight or sensory impairment. The high degree of clinical similarity between patients with late paraphrenia combined with the inability of ICD-10 to define diagnostic subgroups that correspond to patient clusters derived from clinical symptoms or which are meaningfully different from each other in terms of demographic and prognostic factors provide a strong argument for the retention of late paraphrenia as the most appropriate diagnosis for such patients.

Aged↗