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Biomedical subjects

C Mathias

Publications and source records attributed to C Mathias.

At least 19 recordsLinked to original sources
PubMed2006

Testing the validity of the PDQ-39 in patients with MSA.

We assessed the validity of the PDQ-39, a disease-specific health-related quality of life instrument for patients with Parkinson's disease, in patients with multiple system atrophy (MSA). Two hundred and seventy-nine patients completed the PDQ-39, the EQ-5D, the Hospital Anxiety and Depression Scale, and scales of life satisfaction and disease severity. Ceiling and floor effects were noted in some dimensions, and Mobility was skewed towards the severe end of the spectrum. Apart from the dimension of Social Support, all dimensions had high internal consistency. The factor structure of the PDQ-39 in MSA was stable, and convergent and divergent validity with other measures of quality of life and mental health were good. However, many of the specific features of MSA are not reflected in the PDQ-39. Higher order factor analysis did not support the use of a single summary index. We conclude that the PDQ-39 has only limited validity in patients with MSA.

Activities of Daily Living↗
PubMed2006

An open-label, fixed-dose study of bupropion effect on sexual function scores in women treated for breast cancer.

BACKGROUND: Sexual morbidity after chemotherapy and hormonal therapy for breast cancer can seriously affect patients' quality of life. Bupropion is an antidepressant that has been reported to increase libido. OBJECTIVE: To investigate the improvement of sexual function in female breast cancer patients using bupropion. PATIENTS AND METHODS: We performed an 8-week open trial using bupropion in women diagnosed with breast cancer who had received chemotherapy and were currently receiving adjunctive hormonal therapy. The Arizona Sexual Experience Scale (ASEX) was used. The ASEX scale includes five questions that evaluate sexual function in the following areas: libido, excitability and ability to reach orgasm. Women received oral Bupropion 150 mg/daily for 8 weeks and were evaluated prior to the initiation of the study and again during Weeks 4 and 8. RESULTS: Twenty patients were included in the study. At the beginning of the study, the mean ASEX score was 23.45 [21.67-25.24] 95% CI. After 4 weeks of treatment, we observed a reduction in the mean ASEX score that persisted until the end of the study, at eight weeks: 18.45 [16.59-20.31] 95% CI (P = 0.0003) and 18.95 [16.60-21.30] 95% CI (P = 0.0024), respectively. CONCLUSION: In this non-controlled open trial bupropion 150 mg/daily was associated with improved sexual function in women receiving adjuvant systemic treatment for breast cancer.

Antidepressive Agents↗
PubMed2004

Towards improved clinical and physiological assessments of recovery in spinal cord injury: a clinical initiative.

Clinical practice and scientific research may soon lead to treatments designed to repair spinal cord injury. Repair is likely to be partial in the first trials, extending only one or two segments below the original injury. Furthermore, treatments that are becoming available are likely to be applied to the thoracic spinal cord to minimise loss of function resulting from damage to surviving connections. These provisos have prompted research into the improvement of clinical and physiological tests designed (1) to determine the level and density of a spinal cord injury, (2) to provide reliable monitoring of recovery over one or two spinal cord segments, and (3) to provide indices of function provided by thoracic spinal root innervation, presently largely ignored in assessment of spinal cord injury. This article reviews progress of the Clinical Initiative, sponsored by the International Spinal Research Trust, to advance the clinical and physiological tests of sensory, motor and autonomic function needed to achieve these aims.

Animals↗
PubMed2001

Personality and neurocognitive correlates of impulsive aggression in long-term survivors of severe traumatic brain injury.

This study addresses a common outcome of severe traumatic brain injury (TBI), disinhibited aggressive behaviour. This behaviour has been classified in aggression literature as 'impulsive aggression' (IA). The purpose was to: (1) characterize those TBI patients who are likely to be an aggression risk, and (2) determine if TBI patients with IA demonstrate personality style and neurocognitive performance similar to that seen in other IA groups. Participants were 45 survivors of severe TBI (26 of whom had persisting problems with IA), who were clients of a residential brain injury treatment facility. IA participants had a higher incidence of pre-morbid aggressive behaviour, were younger, had a shorter tenure in the programine, and were more impulsive, irritable, and antisocial than the non-aggressive control participants. Unlike past research, no neurocognitive differences were found. The results are discussed in terms of the conceptualization, identification, and treatment of persisting IA in severe TBI.

Adult↗
PubMed2000

Soluble interleukin-2 receptor concentration as a biochemical indicator for acute graft-versus-host disease after allogeneic bone marrow transplantation.

When interleukin-2 (IL-2) binds to the IL-2 receptor (IL2-R) on activated T cells, a soluble portion of the receptor (sIL2-R) is released. After allogeneic bone marrow transplantation (BMT), the serum concentration of sIL2-R may, therefore, be a useful surrogate marker for T cell activation that results in acute graft-versus-host disease (aGVHD). To determine if the sIL2-R concentration is a useful marker to help establish a diagnosis of aGVHD, serial sIL2-R concentrations were measured weekly for 4 weeks in 43 patients after allogeneic BMT. Grafts were from HLA-matched siblings (n = 33), 5/6 HLA-matched siblings (n = 3) or matched unrelated donors (n = 7). GVHD prophylaxis included cyclosporine A (CSA)/methotrexate (MTX) (n = 25), solumedrol/CSA (n = 15), or T cell depletion (n = 3). Twenty-three patients developed aGVHD (Grade I, 7; Grade II, 12; Grade III, 4) a median of 28 days after transplant. There was a significant association between a clinical diagnosis of aGVHD and an increase in the sIL2-R concentration (p < 0.001). The mean percent increase (+/-SE) over baseline for patients with a clinical diagnosis of aGVHD was 294% (+/-57%) by week 2 (n = 12), 431% (+/-116%) by week 3 (n = 14), and 650% (+/-315%) by week 4 (n = 9) after BMT. For each 100% increase over baseline, the likelihood of having aGVHD increased by 18%. Six of 20 patients without aGVHD became critically ill and exhibited marked increases in sIL2-R concentrations, similar to patients with a clinical diagnosis of aGVHD who never became critically ill. Fourteen patients without aGVHD who did not become critically ill exhibited negligible increases of sIL2-R in 2- to 4-week period after BMT. These data suggest that serial measurements sIL2-R concentration are helpful in establishing the diagnosis of aGVHD, but are not useful in the most acutely ill patients.

Acute Disease↗
PubMed2000

Paced Visual Serial Addition Test: an alternative measure of information processing speed.

The Paced Auditory Serial Addition Test (PASAT; Gronwall, 1977; Gronwall & Sampson, 1974) is a measure of attention and information processing speed sensitive to mild traumatic brain injury (MTBI), but it is aversive and inappropriate for many other neurologically impaired patients. This study examines a simpler, less aversive visual analog of the PASAT (the Paced Visual Serial Addition Test; PVSAT) in a sample of 74 college students (26 with a history of TBI). Results indicated that the PVSAT is moderately correlated with and less difficult than the PASAT. Both tests had identical relations to other measures of attention. Neither the PVSAT, PASAT, nor the other attentional measures differentiated participants with MTBI from normal controls in a college population. This preliminary study thus demonstrates the comparability of the two tests and presents the PVSAT as a viable alternative to the PASAT. Directions for future research and applications of these findings are discussed.

Acoustic Stimulation↗
PubMed1999

SDF-1 responsiveness does not correlate with CXCR4 expression levels of developing human bone marrow B cells.

Chemokines and their receptors are broadly expressed in different tissues and are involved in diverse biologic processes. Gene inactivation studies have shown that both stromal cell derived factor-1 (SDF-1) and chemokine receptor 4 (CXCR4) are essential for B lymphopoiesis. However, it is not yet clear by which mechanisms B lymphopoiesis is affected. In the present study, we have examined CXCR4 expression and function on primary B cells representing sequential stages of development (eg, pro-B, pre-B, immature, and mature B cells) in fetal and adult bone marrow. The expression of CXCR4 was observed to be sinusoidal. Expression was highest on pre-B cells, decreased as cells developed into immature B cells, and then increased again upon transition to the mature B-cell stage. The corresponding ligand SDF-1 was shown to trigger vigorous cell signaling and migration responses, which are restricted to early lineage B cells. The responsiveness to SDF-1 was markedly decreased for immature and mature B cells despite relatively high levels of CXCR4 expression. Thus, the diminished responsiveness to SDF-1 by more mature B cells was determined to be disproportionate to the level of CXCR4 expression. These findings raise the possibility that CXCR4 function is differentially controlled during B lymphopoiesis and may be relevant to the compartmentalization of B-cell precursors in the bone marrow.

Adult↗
PubMed1999

[Consensus on the diagnosis of multi-system atrophy].

We report the results of a consensus conference on the diagnosis of multiple system atrophy. We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible multiple system atrophy requires one criterion plus two features from separate domains. The diagnosis of probable multiple system atrophy requires the criterion for autonomic failure/urinary dysfunction plus poor levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite multiple system atrophy requires pathological confirmation.

Diagnosis, Differential↗
PubMed1998

Chronic myelogenous leukemia: extending the prospects for cure.

Advances in our understanding of the molecular defects underlying this leukemia have led to novel therapeutic approaches that have not only altered the natural history of the disease but also apparently effected cures in some patients. The next step may be to offer the possibility of a cure to all patients. Allogeneic bone marrow and T cell transplantation shows promise in this regard.

Bone Marrow Transplantation↗
PubMed1998

Consensus statement on the diagnosis of multiple system atrophy. American Autonomic Society and American Academy of Neurology.

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poor levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Antiparkinson Agents↗
PubMed1998

Role of sodium in contrast medium-induced polymorphic ventricular tachycardia: results in a rabbit model of lengthened QT interval.

RATIONALE AND OBJECTIVES: The authors (a) compared the proarrhythmic effects of ioxaglate (152 mmol/L sodium) and iohexol (no sodium) in a rabbit model and (b) assessed the effect of adding 150 mmol/L sodium to isotonic iohexol. MATERIALS AND METHODS: Either ioxaglate (320 mg of iodine per milliliter) or iohexol (350 mg of iodine per milliliter) was selectively injected into the right coronary artery (1.5 mL over 30 seconds) of 10 rabbits, some of which also received the alpha 1-adrenergic receptor agonist methoxamine. To validate the model, the class III antiarrhythmic agent clofilium was injected intravenously during methoxamine infusion. Frontal electrocardiography was performed continuously to detect polymorphic ventricular tachycardia (PVT). In a second study, the authors assessed the frequency of arrhythmias after injection of isotonic iohexol solution (145 mg of iodine per milliliter), either alone or with 150 mmol/L sodium. RESULTS: Methoxamine significantly lengthened the QT, QTc, and RR intervals (P < .05). The use of clofilium alone induced no PVT, whereas five of eight methoxamine-infused rabbits developed PVT after clofilium injection (P = .03). Both contrast media prolonged the repolarization period. Iohexol alone induced a higher frequency of PVT than did ioxaglate alone (P = .0006). Methoxamine infusion did not potentiate the frequency of PVT in the ioxaglate-injected rabbits. The addition of sodium to isotonic iohexol prevented the occurrence of PVT (P = .0006). CONCLUSION: Although ioxaglate prolonged the repolarization period, it did not cause a higher frequency of arrhythmia when injected in association with methoxamine. Iohexol, which contains no sodium, induced a high frequency of arrhythmia. The addition of a physiologic concentration of sodium to isotonic iohexol can prevent ventricular arrhythmias.

Adrenergic alpha-Agonists↗
PubMed1994

"Minimal change" multiple system atrophy.

We describe the pathological findings in two patients who developed atypical parkinsonism and autonomic failure, leading to a diagnosis of multiple system atrophy (MSA). Postmortem examination of the brain showed cell loss restricted to substantia nigra and locus coeruleus. However, glial cytoplasmic inclusions (GCIs) were present in both cases. We propose that GCIs are highly suggestive of a pathological diagnosis of MSA in the absence of detectable cell loss outside pigmented brain stem nuclei and that brains from cases of atypical parkinsonism should routinely be examined for their presence.

Adult↗
PubMed1993

Small bowel myoelectric activity in peritonitis.

Peritonitis is associated clinically with paralytic ileus, but the physiologic mechanisms of the effects of peritonitis on bowel myoelectric activity have not been explored. Bipolar electrodes were inserted into the rats, and myoelectric control recordings were obtained for 4 h/d for 5 consecutive days. Peritonitis was then induced, and myoelectric recordings were again obtained. Each animal served as its own control. Prior to induction of peritonitis (control), phase I, II, and III myoelectric activity was present in all recordings. The cycle duration of the migrating myoelectric complex was 17.17 +/- 0.39 minutes, and the migration velocity of phase III was 0.61 +/- 0.02 cm/min. The most striking feature during peritonitis was the complete inhibition of phase II activity. Phase III activity, however, was present with a cycle duration of 16.69 +/- 0.42 minutes. This study shows that some features of intestinal myoelectric activity (phase III) are preserved during episodes of peritonitis, and others are changed (phase I) or lost (phase II). Disappearance of phase II activity in this type of ileus emphasizes its importance in normal small bowel motility.

Animals↗
PubMed1990

Left external iliac artery dissection and bilateral renal artery aneurysms secondary to fibromuscular dysplasia: a case report.

A case of acute lower limb ischaemia due to spontaneous dissection of the left external iliac artery and coincidental bilateral renal artery aneurysms is reported. Histopathological examination of the resected iliac artery showed features of fibromuscular dysplasia. Dissection of the external iliac artery without involvement of the aorta is extremely rare with only two previously reported cases. The aetiology and management of fibromuscular dysplasia is discussed.

Acute Disease↗
PubMed1987

Expression of intron-containing C. elegans heat shock genes in mouse cells demonstrates divergence of 3' splice site recognition sequences between nematodes and vertebrates, and an inhibitory effect of heat shock on the mammalian splicing apparatus.

Splicing of a pair of intron-containing heat shock genes from Caenorhabditis elegans has been studied in transfected mouse cells. The hsp16-1 and hsp16-48 genes of C. elegans encode 16,000 Da heat shock polypeptides. Each gene contains a short intron of 52 (hsp16-1) or 55 (hsp16-48) base pairs. When these genes were introduced into mouse cells, they were efficiently induced following heat shock, but splicing of the introns was abnormal. In mouse cells, cleavage of the hsp16 transcripts occurred at the correct 5' splice sites, but the 3' splice sites were located at AG dinucleotides downstream of the correct sites. This aberrant splicing was not solely due to the small size of the C. elegans introns, since a hsp16-1 gene containing an intron enlarged by tandem duplication showed exactly the same splicing pattern. The mouse cells thus seem to be unable to recognize the natural 3' splice sites of the C. elegans transcripts. The efficiency of splicing was greatly reduced under heat shock conditions, and unspliced transcripts accumulated in the nucleus. During a subsequent recovery period at 37 degrees C, these transcripts were spliced and transported to the cytoplasm.

Animals↗
PubMed1987

Unusual cranial and abdominal computed tomographic (CT) scan appearances in a case of systemic lupus erythematosus (SLE).

A 35 year old woman presented with headache and fever. Computed brain tomography showed diffuse low attenuation in the cerebral white matter. Several months later, serological tests for systemic lupus erythematosus (SLE) became positive. In spite of immunosuppressive therapy she relapsed after six months of treatment, presenting with abdominal symptoms and signs. On this occasion an abdominal CT scan showed distended and oedematous loops of bowel attributed to an underlying vasculitis. This case illustrates novel CT scan appearances in two systems involved in SLE.

Adult↗
PubMed1985

Effect of betablockade on dynamic exercise in human heart transplant recipients.

We evaluated the tolerance of heart transplant recipients to acute betablockade during maximal dynamic exercise. Although the increase in rate and systolic blood pressure were attenuated, exercise tolerance was reduced by only about 15%, which is similar to that previously reported in normal individuals. Betablockade attenuated the increases in heart rate of the denervated donor hearts to a greater extent compared to the increases in the innervated recipient hearts in patients with heterotopic heart transplantation. Therefore, betablockers may be safely used in heart transplantation for appropriate indications such as hypertension.

Blood Pressure↗