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Biomedical subjects

R S Howard

Publications and source records attributed to R S Howard.

At least 37 records · Page 2Linked to original sources
PubMed2002

Androgen deprivation in men with prostate cancer is associated with an increased rate of bone loss.

The objective of this work was to determine the effect of androgen deprivation therapy (ADT) on rates of bone mineral density (BMD) loss in men with prostate cancer. It was a prospective study comparing men receiving ADT to age matched controls for 2 y. Subjects received a history, physical exam, bone mineral density measurement, and laboratory evaluation every 6 months. Thirty-nine subjects receiving continuous ADT for prostate cancer (subjects) were compared to 39 age-matched controls not receiving ADT (controls). Twenty-three subjects and 30 controls completed the study through 24 months. Men in the ADT group demonstrated greater rates of bone mineral density loss than men in the control group at every site except the lumbar spine. Twenty-four month per cent of bone mineral density loss is presented as mean+/-standard error (s.e.). At the distal forearm, the ADT group value was -9.4%+/-1.0% and -4.4%+/-0.3% for controls (P<0.0005). The ADT group femoral neck values were -1.9%+/-0.7% and 0.6%+/-0.5% in the control group (P=0.0016). The ADT group total hip value was -1.5%+/-1.0% and 0.8%+/-0.5% in the control group (P=0.0018). The ADT group trochanter value was -2.0%+/-1.3% and -0.1%+/-0.5% in the control group (P=0.0019). The ADT group lumbar spine value was -0.2%+/-0.8 % and 1.1%+/-0.6% in the control group (P=0.079). Our data demonstrate greater rates of bone mineral density loss in men receiving androgen deprivation therapy for prostate cancer.

Absorptiometry, Photon↗
PubMed2002

Outcome of ventilatory support for acute respiratory failure in motor neurone disease.

OBJECTIVES: To review the outcome of acute ventilatory support in patients presenting acutely with respiratory failure, either with an established diagnosis of motor neurone disease (MND) or with a clinical event where the diagnosis of MND has not yet been established. METHODS: Outcome was reviewed in 24 patients with respiratory failure due to MND who received endotracheal intubation and intermittent positive pressure ventilation either at presentation or as a result of the unexpected development of respiratory failure. Patients presenting to local hospitals with acute respiratory insufficiency and requiring tracheal intubation, ventilatory support, and admission to an intensive therapy unit (ITU) before transfer to a regional respiratory care unit were selected. Clinical features of presentation, management, and outcome were studied. RESULTS: 24 patients with MND were identified, all being intubated and ventilated acutely within hours of presentation. 17 patients (71%) were admitted in respiratory failure before the diagnosis of MND had been made; the remaining seven patients (29%) were already known to have MND but deteriorated rapidly such that intubation and ventilation were initiated acutely. Seven patients (29%) died on ITU (between seven and 54 days after admission). 17 patients (71%) were discharged from ITU. 16 patients (67%) received long term respiratory support and one patient required no respiratory support following tracheal extubation. The daily duration of support that was required increased gradually with time. CONCLUSION: When a patient with MND is ventilated acutely, with or without an established diagnosis, independence from the ventilator is rarely achieved. Almost all of these patients need long term ventilatory support and the degree of respiratory support increases with time as the disease progresses. The aim of management should be weaning the patient to the minimum support compatible with symptomatic relief and comfort. Respiratory failure should be anticipated in patients with MND when the diagnosis has been established.

Acute Disease↗
PubMed2002

Management of motor neurone disease.

Motor neurone disease is a progressive neurodegenerative disorder leading to severe disability and death. It is clinically characterised by mixed upper and lower motor neurone involvement affecting bulbar, limb, and respiratory musculature. Recent guidelines have established diagnostic criteria and defined management of the condition. In a proportion of familial amyotrophic lateral sclerosis there is a mutation in the gene encoding the enzyme copper/zinc superoxide dismutase 1; this has allowed mutation screening and generated considerable laboratory based research. The diagnosis must be given with care and consideration and close follow up is essential. Management involves a multidisciplinary team based in the hospital and the community. Riluzole is the only drug shown to have a disease modifying effect and has been approved by the National Institute for Clinical Excellence. The essence of care is good symptomatic management, including nutritional support with percutaneous endoscopic gastrostomy and ventilatory care with non-invasive ventilation. Palliative care should be introduced before the terminal stages after careful discussion with the patient and carers. Knowledge of this condition has grown dramatically recently with a parallel improvement in treatment and ability to deal with the most troublesome problems.

Deglutition Disorders↗
PubMed2001

Rituximab using a thrice weekly dosing schedule in B-cell chronic lymphocytic leukemia and small lymphocytic lymphoma demonstrates clinical activity and acceptable toxicity.

PURPOSE: Rituximab has been reported to have little activity in small lymphocytic lymphoma (SLL)/chronic lymphocytic leukemia (CLL) and to be associated with significant infusion-related toxicity. This study sought to decrease the initial toxicity and optimize the pharmacokinetics with an alternative treatment schedule. PATIENTS AND METHODS: Thirty three patients with SLL/CLL received dose 1 of rituximab (100 mg) over 4 hours. In cohort I (n = 3; 250 mg/m(2)) and cohort II (n = 7; 375 mg/m(2)) rituximab was administered on day 3 and thereafter three times weekly for 4 weeks using a standard administration schedule. Cohort III (n = 23; 375 mg/m(2)) administered rituximab similar to cohort II for the first two treatments and then over 1 hour thereafter. RESULTS: A total of 33 CLL/SLL patients were enrolled; only one patient discontinued therapy because of infusion-related toxicity. Thirteen patients developed transient hypoxemia, hypotension, or dyspnea that were associated with significant changes in baseline interleukin-6, interleukin-8, tumor necrosis factor alpha, and interferon gamma compared with those not experiencing such reactions. Infusion-related toxicity occurred more commonly in older (median age 73 v 62 years; P =.02) patients with no other pretreatment clinical or laboratory features predicting occurrence of these events. The overall response rate was 45% (3% CR, 42% PR; 95% CI 28% to 64%). Median response duration for these 15 patients was 10 months (95% CI, 6.8-13.2; range, 3 to 17+). CONCLUSION: Rituximab administered thrice weekly for 4 weeks demonstrates clinical efficacy and acceptable toxicity. Initial infusion-related events seem to be cytokine mediated and resolve by the third infusion making rapid administration possible. Future combination studies of rituximab with other therapies in CLL seem warranted.

Aged↗
PubMed2001

Brain excitatory amino acid concentrations are lower in the neonatal pig: a buffer against excitotoxicity?

Hypoglycemic brain damage has been associated with high levels of the excitatory amino acids (EAA) aspartate and glutamate in the newborn and adult. We hypothesized that newborn piglet EAA would be different from those of older pigs when stressed with severe insulin-induced hypoglycemia (<30 mg/dl). Brain EAA were measured in piglets and adolescent pigs via microdialysis. Eleven of 12 newborn normoglycemic piglets had no detectable baseline levels (<0.5 microM) of EAA, while pigs had aspartate and glutamate concentrations of 1.78 +/- 0.44 and 3.43 +/- 1.14 microM (mean +/- SEM), respectively. Piglet aspartate and glutamate concentrations reached but did not significantly exceed normoglycemic pig levels after 2 h with plasma glucose values < or =20 mg/ml. Elevations in EAA were only detected in piglets whose EEG activity ceased. Aspartate and glutamate concentrations did not increase in insulin-treated pigs nor in control animals. We speculate that newborns with blood glucose less than clinically acceptable values (35 mg/dl) may be protected from EAA-associated neuronal damage during acute hypoglycemia. Lower normoglycemic and hypoglycemic levels of EAA in newborns when compared to older pigs provide this protection.

Animals↗
PubMed2001

Measurement of isolated subtalar range of motion: a cadaver study.

Fifteen fresh-frozen cadaveric lower extremities were studied to evaluate the reliability of measuring subtalar motion using a bubble inclinometer. There was high intra-observer reliability for manual inversion and eversion of the subtalar joint with the tibiotalar joint locked and unlocked. Poor correlation of radiographic and clinical measurements questioned the validity of bubble inclinometer measurements. The contribution of the tibiotalar joint to apparent subtalar motion, as measured clinically and radiographically, was found to be one-third of the arc of motion, as compared to motion measured clinically and radiographically with the tibiotalar joint locked.

Ankle Joint↗
PubMed2000

Outcome of sulcus fixation of dislocated posterior chamber intraocular lenses using temporary externalization of the haptics.

OBJECTIVE: This study evaluated the visual outcome and complications of repositioning and sulcus fixation of a dislocated posterior chamber intraocular lens (PC IOL) using a technique in which the haptics of the IOL are temporarily externalized for suture placement. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Seventy-eight patients with a dislocated PC IOL. INTERVENTION: All patients underwent surgery to fixate the PC IOL using this technique. MAIN OUTCOME MEASURES: Patients were evaluated for visual acuity, refractive error, and surgical complications associated with the procedure. RESULTS: The average visual acuity before surgery was 20/205 (range, 20/20 to light perception), with a median refractive error of -1.00 diopters (D; range, -7.25-+15.00 D). After surgery, the average visual acuity improved to 20/72 (range, 20/20 to no light perception), with a median refractive error of -0.75 D (range, -5.50-+3.50 D). Patients were observed for a median of 15.5 months (range, 6-57 months). Twenty patients had postoperative cystoid macular edema (26%), 7 patients had an epiretinal membrane (ERM) (9%), and 5 patients had a retinal detachment (6%). Eight patients (10%) experienced iris capture of the sutured IOL, and in three patients (4%) the PC IOL dislocated again after surgery. CONCLUSIONS: This technique is an effective method for securing a dislocated PC IOL.

Adult↗
PubMed1999

Occupational exposure to methyl methacrylate monomer induces generalised neuropathy in a dental technician.

A 36-year-old dental technician for 14 years developed paraesthesia and numbness in her legs. Neurophysiological studies revealed absent sensory nerve action potentials (SNAPs) from her lower limbs and normal upper limb SNAPs on presentation. Motor nerve studies were normal. Repeat studies 2 months after leaving her job showed some improvement in the lower limb SNAPs. It is suggested that her symptoms were caused by occupational exposure to methyl methacrylate monomer.

Adult↗
PubMed1999

Ethnic differences in incidence of stroke: prospective study with stroke register.

OBJECTIVE: To identify ethnic differences in the incidence of first ever stroke. DESIGN: A prospective community stroke register (1995-6) with multiple notification sources. Pathological classification of stroke in all cases was based on brain imaging or necropsy data. Rates were standardised to European and world populations and adjusted for age, sex, and social class in multivariate analysis. SETTING: A multi-ethnic population of 234 533 in south London, of whom 21% are black. RESULTS: 612 strokes were registered. The crude annual incidence rate was 1.3 strokes per 1000 population per year (95% confidence interval 1.20 to 1.41) and 1.25 per 1000 population per year (1.15 to 1.35) age adjusted to the standard European population. Incidence rates adjusted for age and sex were significantly higher in black compared with white people (P<0.0001), with an incidence rate ratio of 2.21 (1.77 to 2.76). In multivariable analysis increasing age (P<0.0001), male sex (P<0.003), black ethnic group (P<0.0001), and lower social class (P<0.0001) in people aged 35-64 were independently associated with an increased incidence of stroke. CONCLUSIONS: Incidence rates of stroke are higher in the black population; this is not explained by confounders such as social class, age, and sex. Ethnic differences in genetic, physiological, and behavioural risk factors for stroke require further elucidation to aid development of effective strategies for stroke prevention in multi-ethnic communities.

Adolescent↗
PubMed1999

Bilateral symmetrical enhancing brainstem lesions: an unusual presentation of primary CNS lymphoma.

We report a patient with a progressive brainstem syndrome, who on magnetic resonance imaging had large bilateral, symmetrical, contrast-enhancing, infratentorial space-occupying lesions. Biopsy of one of the lesions revealed this unusual appearance to be due to a primary central nervous system (CNS) lymphoma of B-cell type. Symmetry of lesions may be a clue to the diagnosis, perhaps reflecting the mechanism by which CNS lymphomas spread.

Aged↗
PubMed1999

Lectin binding to human colonocytes is predictive of colonic neoplasia.

OBJECTIVE: The aim of this study was to determine whether lectin binding to exfoliated human colonocytes could be used as a noninvasive test for colorectal polyps or cancer. METHODS: Colonocytes were harvested from 31 patients (10 controls, 10 with adenomatous polyps, and 11 with cancer), incubated with a panel of fluorescent-labeled lectins, and assayed by flow cytometry. RESULTS: The lectins jacalin (JAC) and wheat germ agglutinin (WGA) were useful in predicting the presence of a colorectal neoplasm (p = 0.0018 for JAC and p = 0.0099 for WGA). For JAC, sensitivity reached 81% with a specificity of 80%, and for WGA the sensitivity and specificity were both 75%. CONCLUSIONS: Lectin binding to human colonocytes can predict the presence of malignant and premalignant lesions of the colon, and has potential as a noninvasive screening tool for colorectal neoplasms.

Adenomatous Polyps↗
PubMed1999

High-grade glioma mimicking acute viral encephalitis--three case reports.

The clinical features of viral encephalitis consist of headache, fever, seizures and encephalopathy. We report three patients with high-grade gliomas presenting with encephalitic illnesses. The diagnosis of brain tumour should always be borne in mind if definite evidence for a viral infection is not obtained.

Acute Disease↗
PubMed1999

CD56 expression in acute promyelocytic leukemia: a possible indicator of poor treatment outcome?

PURPOSE: Blast expression of CD56 is frequent in patients with t(8;21)(q22;q22) acute myeloid leukemia and is associated with an inferior outcome. The expression of CD56 has rarely been reported in acute promyelocytic leukemia (APL) and has not been clinically characterized. Therefore, we examined the prognostic significance of CD56 expression in APL. PATIENTS AND METHODS: We identified all reported cases of CD56+ APL in the medical literature and collected clinical, biologic, and therapeutic details. RESULTS: Data were obtained for 12 patients with CD56+ APL (> 20% blast expression of CD56), including four cases from a single institution with a total of 42 APL patients. All of the CD56+ APL patients had documented cytogenetic presence of t(15;17), and of the nine reported isotypes, eight (89%) were S-isoform. Only six CD56+ patients (50%) attained complete remission (CR); the other six individuals died within 35 days of presentation. Of the six patients who attained a CR, three (50%) relapsed at 111, 121, and 155 weeks, whereas three remained in continuous CR at 19, 90, and 109 weeks. Comparison of the control CD56- to CD56+ APL patients demonstrated that the latter group had a significantly lower fibrinogen level (P = .007), and among patients for whom data were available, there was a higher frequency of the S-isoform (P = .006). Additionally, the CR rate (50% v 84%, P = .025) and overall median survival (5 v 232 weeks; P = .019) were significantly inferior for CD56+ APL patients. CONCLUSION: CD56+ acute promyelocytic leukemia is infrequent, seems to occur more frequently with the S-isoform subtype, and may be associated with a lower CR rate and inferior overall survival.

Adult↗