Biomedical subjects

R Hofman

Publications and source records attributed to R Hofman.

10 recordsLinked to original sources

PubMed2005

The relationship of the round window membrane to the cochlear aqueduct shown in three-dimensional imaging.

The round window membrane and cochlear aqueduct complex in the guinea pig are reconstructed with 3D-imaging, using orthogonal plane fluorescence optical sectioning (OPFOS). The 3D-images show that the periotic duct and the aqueduct are connected to a pouch-like extension of the round window. The function of this may be regulation of aqueduct flow resistance under the influence of a pressure difference between inner ear fluid and middle ear.

Animals↗

PubMed1999

[Carotid stenting: acute results and complications].

The treatment of carotid stenoses with balloon angioplasty and stenting is a new and not generally established method. During a one year period 65 patients (22 female, 43 male, mean age: 73 years, 47 with neurologic symptoms, 8 with contralateral carotid occlusion) with significant (>70%) carotid stenosis were treated with balloon angioplasty and balloon expandable stents. The primary technical success rate was 98% (65/66 patients) respectively 99% (69/70 stenoses). A combined procedure was performed in 11 /17%) patients with stenting in both carotid arteries in 4 patients with additional coronary interventions in 6 patients and stenting of the origin of the common carotid artery in one patient.Severe neurologic complications occurred in 4 (6.2%) patients (1 death, 1 major stroke, 2 minor strokes) and short lasting neurologic deficits in additional 4 (6.2%) patients. Cardiovascular complications were not observed. Local (inguinal) problems occurred in 3 (4.5%) patients (2 aneurysma spuria, 1 transfusion for hematoma). Frequently, balloon insufflation was associated with bradycardia (40%) and additional hypotension (11%). In summary, carotid stenting can be performed with technically high success rates (99%), but it is adversely influenced by not infrequent thromboembolic cerebral events (12.4%). The possibility to perform combined procedures with interventions in other vessels (both carotid arteries, coronary arteries, aortic arch arteries) is advantageous.

Aged↗

PubMed1994

Characterization of swallowing and defecation in Parkinson's disease.

UNLABELLED: Despite the high prevalence of Parkinson's disease, the pathophysiology of its gastrointestinal symptoms remains poorly understood. OBJECTIVES: to evaluate swallowing and defecatory function in patients with Parkinson's disease and age- and sex-matched controls and to correlate objective findings with subjective symptoms. METHODS: The following studies were performed on 13 patients with Parkinson's disease and seven controls: extrapyramidal function assessment, gastrointestinal symptom survey, videoesophagram, colon transit study, defecography, and anorectal manometry. RESULTS: Abnormal salivation (frequency, %, control vs. Parkinson's disease: 14 vs. 77, p < 0.05), dysphagia (14 vs. 77, p < 0.05), constipation (14 vs. 31, p < 0.05), and defecatory dysfunction (29 vs. 77, p < 0.05) were more common among Parkinsonian patients. However, videoesophagographic abnormalities were equally common in both groups. Colon transit time was significantly prolonged in the Parkinson's disease group. Altered puborectalis function was noted on defecography in 31% of Parkinson's disease subjects, but in none of the controls (p < 0.05). Anorectal manometry identified several abnormalities in the Parkinson's disease group, which included decreased basal anal sphincter pressures, prominent phasic fluctuations on squeeze, and a hyper-contractile external sphincter response to the rectosphincteric reflex. Many patients exhibited both slow transit and manometric abnormalities, and symptoms were poor predictors of test results. CONCLUSION: In this group of patients with mild to moderate Parkinson's disease, videoesophagographic abnormalities were not confined to the patients with Parkinson's disease. Studies of colonic and anorectal function, in contrast, identified a number of abnormalities. Therefore, colonic and anorectal dysfunction appears to be an early gastrointestinal manifestation of Parkinson's disease, and may represent the direct involvement of the gut by this disease process.

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PubMed1993

Defecatory function in Parkinson's disease: response to apomorphine.

We evaluated the effects of the dopaminergic agent apomorphine on defecation and anorectal function in patients with Parkinson's disease (PD). A gastrointestinal symptom survey, extrapyramidal assessment, defecating proctogram, and anorectal manometric study were performed in 8 subjects with PD. Basal studies showing abnormalities were repeated following apomorphine administration. Prior defecographic abnormalities were normalized following apomorphine injection in 1 of 3 subjects and significant improvements in manometric parameters were observed in all 5 subjects who underwent repeat anorectal manometry. We conclude that apomorphine can correct anorectal dysfunction in PD, and that these abnormalities may be a consequence of dopamine deficiency secondary to the PD process. These findings may also have therapeutic implications.

Aged↗

PubMed1993

Gastrointestinal symptoms in Parkinson disease: 18-month follow-up study.

In a recent study we identified abnormal salivation, dysphagia, nausea, constipation, and defecatory dysfunction as those gastrointestinal (GI) symptoms associated with Parkinson disease (PD) and characterized their relationship to PD severity and therapy. In this study, we re-evaluated these symptoms and their relationship to parameters of PD 18 months later. Sixty-six percent of the original participants responded. Over the 18 months, 68% of originally untreated PD subjects commenced anti-PD therapy. Abnormal salivation, dysphagia, nausea, constipation, and defecatory dysfunction were again identified as those GI symptoms more common in PD. Constipation increased both in severity and frequency. Comparison of GI symptom scores and parameters of PD dysfunction failed to reveal significant progression of either GI symptomatology or PD dysfunction, or the development of new GI symptoms over the 18-month period. This study validates our GI dysfunction assessment system and confirms abnormal salivation, dysphagia, nausea, constipation, and defecatory function as those GI symptoms truly associated with PD. A direct relationship between PD and its related GI symptoms is again supported.

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PubMed1991

Gastrointestinal symptoms in Parkinson's disease.

We have investigated the prevalence of gastrointestinal (GI) symptoms in 98 individuals with Parkinson's disease (PD) and in a control group of 50. Seventy-nine of those with PD were being treated with dopaminergic medications and 19 were untreated. Those symptoms occurring more frequently in PD patients than in controls included abnormal salivation, dysphagia, nausea, constipation, and defecatory dysfunction. Except for defecatory dysfunction, symptoms did not correlate with treatment but instead correlated with disease severity. This suggests that the GI symptoms of PD reflect direct involvement in the GI tract by the primary disease process.

Aged↗

PubMed1991

CQA 206-291 in Parkinson's disease.

CQA 206-291, a mixed D1-D2 receptor agonist that also possesses dualistic dopamine antagonist-agonist properties, was investigated in a double-blind, placebo-controlled trial in individuals with Parkinson's disease of moderate severity. Significant improvement was noted in the treatment groups compared to the placebo group. Adverse effects were generally mild and transient. CQA appears to be an effective, well-tolerated agent in the treatment of Parkinson's disease. Nevertheless, because of laboratory-based toxicity concerns, CQA has been withdrawn from further human study and will not be developed clinically.

Activities of Daily Living↗

PubMed1991

Sinemet CR in Parkinson's disease.

Sinemet CR, a controlled release carbidopa/levodopa preparation, was compared to conventional carbidopa/levodopa in a double blind, placebo-controlled trial. Comparable clinical benefits and adverse effects were noted with the two medications. However significantly less frequent dosing was necessary with Sinemet CR.

Aged↗

PubMed1990

Clozapine for psychosis in Parkinson's disease.

The clinical efficacy of clozapine, an atypical antipsychotic, in treating levodopa-induced hallucinations was investigated in five patients with Parkinson's disease under open label conditions. Two patients could not tolerate clozapine, even in doses as low as 12.5-25 mg daily, because of extreme sedation. Three patients could tolerate clozapine and experienced improvement or elimination of their hallucinations at doses below 100 mg daily. Despite a significant risk of adverse effects, cautious use of clozapine in low doses may be beneficial for patients with levodopa-induced psychosis who do not respond to more conservative measures.

Aged↗

PubMed1986

Sibs with the polyasplenia developmental field defect.

We report on two brothers each with absent spleen, multiple cardiac defects, and varying degrees of situs inversus. One brother also had omphalocele; the other also had annular pancreas. These findings are consistent with a diagnosis of polyasplenia, a complex developmental field defect affecting visceral and cardiac situs, with associated spleen and heart defects. We also discuss familial cases from a developmental field perspective.

Abnormalities, Multiple↗