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Biomedical subjects

M Richmond

Publications and source records attributed to M Richmond.

At least 19 recordsLinked to original sources
PubMed2006

Jaw complications associated with bisphosphonate use in patients with plasma cell dyscrasias.

Osteonecrosis of the jaw has been linked with bisphosphonate use in breast cancer and multiple myeloma patients. We report 17 cases of patients with plasma cell dyscrasia being treated with bisphosphonate who developed osteonecrosis/osteomyelitis of the jaw. Seventeen patients evaluated at our institution between 1998 and 2005 are reported. All were being treated with bisphosphonates for a median of 5 mo prior to the onset of jaw symptoms. Sixteen of the 17 patients are 51 yr or older. None of the patients had been irradiated in the jaw nor had obvious osseous manifestation of multiple myeloma in the jaw. Thirteen patients were receiving zoledronic acid and four patients were receiving pamidronate at the onset of jaw symptoms. Six of the 17 did receive both agents at some time and all of these individuals were receiving zoledronic acid at diagnosis. Microorganisms were isolated in 7/17 patients with the most common organism being actinomycosis. We have initiated the following guidelines in an effort to ameliorate the incidence of this complication. Patients should have a full dental examination at the time of diagnosis of the plasma cell dyscrasia especially if bisphosphonates are to be considered as part of the therapy. In addition, bisphosphonates are held for a period of 3 mo prior to invasive dental procedures to allow for the osteoclastic recovery, therefore enhanced debris removal and lessening the chance of creating a fertile bacterial medium. Following the dental procedure we would re-introduce bisphosphonates only after the healing process is complete. Finally, multiple myeloma patients diagnosed with jaw osteonecrosis probably have a concurrent infection and should be aggressively treated with antibiotics.

Adult↗
PubMed2004

An X-ray outburst from the rapidly accreting young star that illuminates McNeil's nebula.

Young, low-mass stars are luminous X-ray sources whose powerful X-ray flares may exert a profound influence over the process of planet formation. The origin of the X-ray emission is uncertain. Although many (or perhaps most) recently formed, low-mass stars emit X-rays as a consequence of solar-like coronal activity, it has also been suggested that X-ray emission may be a direct result of mass accretion onto the forming star. Here we report X-ray imaging spectroscopy observations which reveal a factor approximately 50 increase in the X-ray flux from a young star that is at present undergoing a spectacular optical/infrared outburst (this star illuminates McNeil's nebula). The outburst seems to be due to the sudden onset of a phase of rapid accretion. The coincidence of a surge in X-ray brightness with the optical/infrared eruption demonstrates that strongly enhanced high-energy emission from young stars can occur as a consequence of high accretion rates. We suggest that such accretion-enhanced X-ray emission from erupting young stars may be short-lived, because intense star-disk magnetospheric interactions are quenched rapidly by the subsequent flood of new material onto the star.

Journal Article↗
PubMed2002

IL-1, IL-6 and TNF-alpha concentrations in the peritoneal fluid of women with pelvic adhesions.

BACKGROUND: Pelvic adhesions are a significant cause of morbidity and are associated with infertility and pain. The three pro-inflammatory cytokines interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-alpha are involved in adhesion formation/reformation. METHODS: The concentration of these three cytokines was examined in the peritoneal fluid of women undergoing laparoscopy, in order to examine the factors affecting their concentrations, with specific reference to the presence or absence of adhesions. RESULTS: We found that the concentration of TNF-alpha in the peritoneal fluid was significantly correlated to the menstrual cycle day (P < 0.01), with increasing concentration as the menstrual cycle progressed from the follicular to the luteal phase. In contrast, IL-1 and IL-6 levels did not show any variation throughout the menstrual cycle. Increased TNF-alpha was found in patients with pelvic adhesions compared with those with normal pelvis; the concentration of TNF-alpha was highest in mild compared with severe adhesions. In contrast, IL-1 concentration was higher in the presence of severe adhesions. IL-6 levels were significantly correlated with the grade of endometriosis (P < 0.05), but there were no significant correlations of either TNF-alpha or IL-1 concentrations with the various grades of endometriosis. CONCLUSION: The exact role of TNF-alpha and IL-1 in adhesion formation is still unknown, but the results from this study suggest that their concentration in the peritoneal fluid is associated with the degree of adhesions present.

Adnexal Diseases↗
PubMed2001

Rumination and cigarette smoking: a bad combination for depressive outcomes?

Ruminative coping has been shown to heighten the risk and severity of depression. The authors hypothesized that ruminators who smoke would experience greater depressive symptoms than ruminators who do not. The rationale is that, by heightening attentional focus, nicotine may increase ruminators' ability to focus on negative thoughts, augmenting depressed mood. Participants (N = 145) self-reported smoking status, rumination, and current and lifetime depressive symptoms, including depressed mood. Results showed that rumination accounted for a larger amount of variance in current and past depressed mood and severity of lifetime depressive symptoms among smokers than nonsmokers. Noncorrelational, experimental research should directly test whether nicotine worsens depressed mood among ruminative smokers. Such evidence would be surprising because it would contradict the assumption that nicotine dispels negative moods.

Adaptation, Psychological↗
PubMed2001

Visual function and quality of life among patients with giant cell (temporal) arteritis.

OBJECTIVE: To investigate patient perception of visual and systemic disability associated with giant cell arteritis (GCA) and whether the perceived disability can be correlated with visual performance measures. METHODS: We prospectively evaluated and compared the visual performance and quality of life survey for 20 patients with GCA after 4 to 5 weeks of corticosteroid therapy and after one year of therapy. We measured visual acuity, contrast sensitivity, and threshold perimetry and patients completed the Activities of Daily Vision Scale (ADVS) and the short-form of the Health Survey (SF-36). The results were grouped by GCA affected or unaffected eye or by better or worse eye and reported as a decimal and percent impairment for acuity, log units for contrast, mean deviation and the Advanced Glaucoma Intervention Study (AGIS) score for perimetry. The results for patients with and without visual loss were compared. Correlation analyses between ADVS categories and visual performance measures, SF-36 categories and the presence of visual loss, total corticosteroid dose, systemic symptoms, secondary hypertension or diabetes mellitus, the presence of vertebral fracture, and visual performance were performed. RESULTS: Day driving was the only ADVS category significantly reduced at baseline in patients with visual loss (62.5) compared with those without visual loss (96.3, P = 0.04). Modest to moderate correlations between ADVS categories were most frequent for percent binocular acuity impairment with day driving (r = -0.62, P = 0.017), with distance vision (r = -0.5, P = 0.02), and with glare (r = -0.59, P = 0.006); and the AGIS score of the worse eye with day driving (r = -0.66, P = 0.01), with near vision (r = -0.49, P = 0.03), and with glare (r = -0.48, P = 0.04). The baseline SF-36 scores did not correlate with the presence of vision loss at baseline or systemic complications. The ADVS and SF-36 scores were similar at one year. The total dose of corticosteroids only had a modest correlation with the one-year mental health score (r = -0.45, P = 0.05), but there was no correlation between SF-36 scores and other systemic side effects of steroid therapy. CONCLUSION: Except for the day driving score, the ADVS did not differ between patients with and without visual loss. The SF-36 did not distinguish between patients with and without visual loss and did not reveal significant trends. The ADVS and SF-36 did not reveal significant disability in GCA patients and there were no strong correlations with any visual performance or systemic measures.

Activities of Daily Living↗
PubMed2000

Specific role of the extracellular signal-regulated kinase pathway in angiotensin II-induced cardiac hypertrophy in vitro.

Although MAP (mitogen-activated protein) kinases are implicated in cell proliferation and differentiation in many cell types, the role of MAP kinases in cardiac hypertrophy remains unclear. We examined the role of extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 MAP kinase in angiotensin II (Ang II)-induced hypertrophy compared with phenylephrine-induced hypertrophy in neonatal rat cardiac myocytes. Both Ang II and phenylephrine activated ERKs to a similar extent, whereas phenylephrine caused stronger and more sustained activation of JNK and p38 than Ang II. PD98059, a specific inhibitor of MAPK/ERK kinase (MEK),inhibited Ang II-induced, but not phenylephrine-induced, expression of atrial natriuretic factor (ANF) at both the mRNA and polypeptide levels. SB203580, a specific inhibitor of p38 and some JNK isoforms, did not show significant effects on ANF expression induced by Ang II or phenylephrine. Although PD98059 and dominant-negative MEK1 blocked Ang II-induced activation of the ANF promoter, SB203580 or dominant-negative MEK kinase 1 (MEKK1) showed no effect. Phenylephrine-induced ANF promoter activation was significantly inhibited by SB203580 and dominant-negative MEKK1, but not by PD98059 or dominant-negative MEK1. Dominant-negative Ras inhibited both ERK activation and ANF up-regulation by Ang II, whereas constitutively active forms of Ras and MEK were sufficient to activate the ANF promoter. Dominant-negative Ras also partly inhibited the phenylephrine-induced activation of ANF promoter. PD98059 did not affect other markers of Ang II-induced hypertrophy, such as skeletal alpha-actin and c-fos expression, increases in the rate of protein synthesis or rapid sarcomeric actin organization. These results suggest that Ang II uses ERK for ANF expression, whereas phenylephrine uses other pathways. The Ras/ERK pathway selectively mediates ANF expression in various phenotypes observed in Ang II-induced hypertrophy. The ERK pathway mediates an agonist-specific and phenotype-specific response in cardiac hypertrophy.

Angiotensin II↗
PubMed1999

The effects of hippocampal and fimbria-fornix lesions on prepulse inhibition.

The present experiments tested the effects of conventional (dorsal aspiration and electrolytic) and excitotoxic (N-methyl-D-aspartate [NMDA]) hippocampal lesions and fimbria-fornix (FF) transection on prepulse inhibition (PPI) of startle response and on open-field activity. Activity was increased by FF transection and by conventional but not excitotoxic hippocampal lesions; complete NMDA lesion increased amphetamine-induced activity. Whereas dorsal hippocampal aspiration lesion disrupted PPI, the phenomenon was not affected by dorsal hippocampal electrolytic lesion, partial or complete excitotoxic (NMDA) hippocampal lesions, or complete FF transection, which interrupted the cholinergic input to the hippocampus as well as the hippocampal-subicular input to the nucleus accumbens. Systemic apomorphine disrupted PPI in both FF-transected rats and their controls. It is suggested that the hippocampus is essential for PPI disruption rather than for PPI expression.

Acoustic Stimulation↗
PubMed1999

Visual performance in giant cell arteritis (temporal arteritis) after 1 year of therapy.

AIMS: To determine if patients with giant cell arteritis (GCA) treated with corticosteroids develop delayed visual loss or drug related ocular complications. METHODS: In a multicentre prospective study patients with GCA (using precise diagnostic criteria) had ophthalmic evaluations at predetermined intervals up to 1 year. The dose of corticosteroid was determined by treating physicians, often outside the study, with the daily dose reduced to the equivalent of 30-40 mg of prednisone within 5 weeks. Subsequently, treatment guidelines suggested that the dose be reduced as tolerated or the patient was withdrawn from steroids in a period not less than 6 months. RESULTS: At presentation, of the 22 patients enrolled, seven patients had nine eyes with ischaemic injury. Four eyes had improved visual acuity by two lines or more within 1 month of starting corticosteroids. No patients developed late visual loss as the steroid dose was reduced. At 1 year the visual acuity, contrast sensitivity, colour vision, and threshold perimetry were not significantly different from the 4-5 week determinations. At 1 year, there were no significant cataractous or glaucomatous changes. At 2 months, there was no difference in systemic complications between patients who received conventional dose (60-80 mg per day) or very high doses (200-1000 mg per day) of corticosteroids at the start or early in the course. CONCLUSIONS: Patients with GCA related visual loss can improve with treatment. Corticosteroids with starting doses of 60-1000 mg per day, with reduction to daily doses of 40-50 mg per day given for 4-6 weeks, and gradual dose reduction thereafter, as clinically permitted, did not result in delayed visual loss. There were no significant drug related ophthalmic complications.

Adrenal Cortex Hormones↗
PubMed1990

Teaching home care for ventilator-dependent patients: the patients' perception.

An increasing number of ventilator-dependent patients are being transferred from hospitals to their homes. Discharge teaching has been based on health professionals' perception of what patients need to know and how they can learn best. In this study we asked ventilator-dependent patients who were living at home (N = 13) to complete a questionnaire concerning their perceptions of ideal discharge teaching. Most respondents believed that teaching should occur (1) at the bedside, (2) with one or two family members, (3) with only the team member doing the teaching, (4) for a 30-minute session, (5) using demonstration technique. Subjects thought that teaching regarding the lung disease process was less important than other content. The patients' criteria for learning mostly agree with those identified by health care professionals, and can be met easily in most settings.

Adolescent↗
PubMed1987

Water metabolism in free-ranging pine voles (Microtus pinetorum).

Rates of body water turnover in free-ranging pine voles exceeded those reported for a large number of similarly sized mammals. Concentrations of urine obtained from free-ranging pine voles were significantly lower than values published for other free-ranging mammals and also for laboratory-maintained members of this species. Rates of body water turnover in this species were not correlated with seasonal changes in soil temperatures.

Animals↗
PubMed1985

Central anticholinergic syndrome in a child: a case report.

A 2-year-old boy developed classical signs and symptoms of the central anticholinergic syndrome after ingesting twenty 4-mg tablets of the antihistamine cyproheptadine (Periactin). His symptoms were dramatically reversed by the intravenous administration of physostigmine. The physiology of the anticholinergic system and physostigmine are discussed along with the indications, toxicity, and dosing of physostigmine.

Child, Preschool↗
PubMed1981

Analysis of mesenchyme in the developing hind limb of Rana pipiens larvae with implications for neural development.

Mesenchyme in the hind limbs of Rana pipiens tadpoles may serve as an important influence on the development of specific neural structures involved in limb innervation. Thus a histological quantification of mesenchyme was undertaken to identify landmark stages with respect to mesenchyme presence and neural events. Mesenchyme remained as a high percentage of the limb tissue until stage V (Taylor-Kollros stages, '46), after which it declined dramatically until its virtual absence after stage XI. The volume of mesenchyme, however, was greatest at stages VIII-IX. Periods of high and low mesenchyme content were correlated in time with potential limb involvement in regulating limb innervation and motor neuron loss from the lateral motor columns. This provides additional evidence for developmental relationships between events of the limb and neural tissues.

Animals↗
PubMed1977

Crohn's disease of the duodenum.

Crohn's disease of the duodenum is uncommon, occurring in approximately 2% of patients with Crohn's disease. Approximately 165 cases have been reported in small series in the literature. Our report includes 36 patients, most of whom had symptoms of duodenal disease coincident with or after obvious disease elsewhere in the gastrointestinal tract, although occasionally duodenal disease developed first and rarely disease was confined to the duodenum. Upper abdominal pain and symptoms of gastroduodenal obstruction are the commonest patterns of presentation. Significant weight loss is common, and occasionally major upper gastrointestinal bleeding occurs. The commonest pattern of involvement was contiguous disease of the proximal duodenum and distal stomach. Endoscopically, diffuse granularity, nodularity, and ulceration are seen accompanied by lack of distensibility of the involved area. Granulomas are rarely found in endoscopic biopsies. A bypass procedure was carried out on 18 patients, 15 of whom continue to be free of symptoms with an average follow-up of 6-6 years. When symptoms of obstruction dictate, operative bypass is accompanied by favourable long-term results in the large majority of patients.

Adolescent↗