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Biomedical subjects

H Kaufmann

Publications and source records attributed to H Kaufmann.

270 records · Page 15Linked to original sources
PubMedDate not supplied

The length-tension diagrams of human oblique muscles in trochlear palsy and strabismus sursoadductorius.

We determined the relation between length and tension in detached oblique muscles of 16 strabismus patients that underwent surgery, before and during contraction evoked by intravenous administration of succinylcholine. We frequently found a nonlinear relation between length and tension, unlike our previous findings in recti. In superior oblique palsies, the superior oblique was found, before injection of succinylcholine, to be stiff after elongation, and did not contract after injection of succinylcholine, while the ipsilateral inferior oblique contract after injection of succinylcholine, but with a higher spring constant than did usual. In 3 cases the superior oblique contracted vividly after administration of succinylcholine despite the presence of excyclotropia, stereopsis, torticollis (2 cases) and a hypertropia that increased in adduction, in downgaze, in adduction-and-downgaze and on ipsilateral head-tilt. The finding of a vividly contracting superior oblique is incompatible with the diagnosis of a complete superior oblique palsy. We conclude that some of the cases diagnosed as congenital superior oblique palsy, having a hypertropia increasing in adduction, in downgaze, in adduction-and-downgaze and on ipsilateral head-tilt, are in fact cases of unilateral strabismus sursoadductorius (upshoot in adduction), a non-paretic motility disorder.

Adolescent↗
PubMedDate not supplied

[Current standards for body height and weight of Swiss children and adolescents 4 to 19 1/2 years old (Geneva 1972)].

New tables have recently been published containing (1) the usual percentiles of body weight and stature in each of the successive 6 months age groups, (2) two different age independent estimates of weight percentiles related to height, and (3) 50%, 80%, and 95% contours for the bivariate joint distribution of height and weight in each age group. All of the tables and charts are given for boys and girls separately. In view of the randomness of the sampling and the characteristic heterogeneity of the population concerned, these new normal limits may be declared valid not only for the entire Swiss area, but even for adjacent regions.

Adolescent↗
PubMedDate not supplied

Plasma endothelin during upright tilt: relevance for orthostatic hypotension?

Since plasma endothelin concentration increases with upright posture and decreases with volume expansion, a study was conducted to test whether activation of the baroreceptor reflex releases endothelin into plasma. The effect of passive upright tilt on the plasma concentrations of endothelin and vasopressin was examined in: (1) normal subjects; (2) patients with impaired baroreceptor reflex due to primary autonomic failure; (3) patients with normal afferent baroreceptor function but acute inhibition of vasoconstrictor sympathetic outflow (ie, with vasovagal syncope); and (4) patients with hypophysial diabetes insipidus. In normal subjects, upright tilt did not change arterial pressure and significantly increased the plasma concentrations of endothelin and vasopressin. In patients with autonomic failure, upright tilt induced a considerable fall in arterial pressure, no rise in plasma endothelin, and a slight increase in plasma vasopressin. In subjects with vasovagal syncope, arterial pressure dropped and the plasma concentrations of endothelin and vasopressin rose. In the subjects with diabetes insipidus, arterial pressure fell slightly, without change in plasma concentration of endothelin. The results suggest that activation of the baroreceptor reflex induces the release of endothelin into plasma, probably from the neurohypophysis, and they raise the possibility that impaired endothelin release contributes to the orthostatic hypotension of patients with primary autonomic failure.

Adult↗
PubMedDate not supplied

Ulcerative breast cancer: case report and review of management.

In the literature, there is an astonishingly small amount of information on specific treatment modalities of locally advanced, ulcerated breast cancer. Here we present a case report and a literature review on ulceration in breast cancer. An older, so far untreated woman with complete ulcerative destruction of her right breast was inoperable because of the extent of the tumor. Primary anthracycline-based chemotherapy and hormonal therapy led to major tumor shrinkage with complete ulcer healing, which was maintained for nearly 2 years. There is increasing evidence from the literature that primary chemotherapy may particularly benefit patients with inoperable ulceration, as also illustrated by our case.

Aged↗
PubMedDate not supplied

Direct evidence of acute, massive striatal dopamine release in gerbils with unilateral strokes.

Dopamine release into the extracellular space was measured with in vivo electrochemical detection in the ipsilateral and contralateral striata in Mongolian gerbils that suffered a stroke after acute unilateral carotid artery ligations. A sevenfold increase in the dopamine signal occurred within 15 minutes of carotid ligation in the ischemic side, while the unlesioned side had no significant change. Increased extracellular levels of dopamine persisted throughout the 3-hour recording period. Pretreatment with alpha-methyl-p-tyrosine 6 hours prior to recording significantly attenuated the signal increase. This study is the first direct demonstration of the marked, continuous dopamine release that occurs during acute cerebral ischemia.

Animals↗
PubMedDate not supplied

[Orthostatic intolerance and syncope].

OBJECTIVE: To describe the current state of knowledge and clinical features of patients with othostatic intolerance. METHOD: Patients with orthostatic intolerance can be classified in two types. In one of them, sympathetic activity is diminished and they have hypotension when they stand up. This becomes chronic in patients with central or peripheral neurodegenerative diseases and is acute in those with vasovagal syncope. In the second type of orthostatic intolerance patients display an increase in sympathetic activity, without arterial hypotension and a notable tachycardia, this is called postural tachycardia syndrome. The mechanism responsible for this type of orthostatic intolerance and the exact cause of the characteristic symptoms are unknown. Diverse theories include a neuropathic lesion that affects the nerves in the lower part of the body in a selective fashion or a congenital or acquired defect in the neuronal norepinephrine transporter. CONCLUSIONS: Orthostatic intolerance is the difficulty experienced by patients to remain standing due to a dysfunction of the autonomic nervous system. Orthostatic intolerance occurs when efferent sympathetic activity is notably diminished or, paradoxically, in patients in whom efferent sympathetic activity increases in an exaggerated manner when they stand up.

Syncope↗
PubMedDate not supplied

[The most common dysautonomias].

AIMS: To review the classification and the clinical and pathological characteristics of the most common dysautonomias. METHOD: Primary dysautonomia includes neurodegenerative diseases of unknown causes that are characterised by the intracytoplasmic accumulations of alpha synuclein that manifest with four different phenotypes: pure autonomic failure, Parkinson s disease, dementia with Lewy bodies and multiple system atrophy. Of the secondary dysautonomias, diabetes mellitus is the most common cause of autonomic neuropathy in developed countries. Familiar dysautonomia is a recessive autosomic disease; the gene responsible for it has been located in the long arm of chromosome 9 (9q31). Paraneoplasic dysautonomia is associated with cancer of the lungs, the pancreas, Hodgkin's disease and testicular cancer. In Lambert Eaton myasthenic syndrome and in botulism the release of acetylcholine is deficient in both the somatic and the autonomic neurons. There are other diseases that affect autonomic cholinergic neurotransmission without bringing about any disorders in neuromuscular transmission. Chagas disease affects the neurons of the parasympathetic ganglion and produces megaesophagus, megacolon and myocardiopathy. Dopamine beta hydroxylase enzyme deficiency is a congenital disease characterised by the failure to convert dopamine into noradrenaline which results in orthostatic hypotension. CONCLUSIONS: Dysautonomias can be classified, according to their aetiology, as primary or secondary; according to the deficient neurotransmitter, as cholinergic, adrenergic and mixed (pan dysautonomia) or, according to the anatomical distribution of the neurons that are affected, as central and peripheral.

Autonomic Nervous System Diseases↗
PubMedDate not supplied

Vestibular influences on autonomic cardiovascular control in humans.

There is substantial evidence that anatomical connections exist between vestibular and autonomic nuclei. Animal studies have shown functional interactions between the vestibular and autonomic systems. The nature of these interactions, however, is complex and has not been fully defined. Vestibular stimulation has been consistently found to reduce blood pressure in animals. Given the potential interaction between vestibular and autonomic pathways this finding could be explained by a reduction in sympathetic activity. However, rather than sympathetic inhibition, vestibular stimulation has consistently been shown to increase sympathetic outflow in cardiac and splanchnic vascular beds in most experimental models. Several clinical observations suggest that a link between vestibular and autonomic systems may also exist in humans. However, direct evidence for vestibular/autonomic interactions in humans is sparse. Motion sickness has been found to induce forearm vasodilation and reduce baroreflex gain, and head down neck flexion induces transient forearm and calf vasoconstriction. On the other hand, studies using optokinetic stimulation have found either very small, variable, or inconsistent changes in heart rate and blood pressure, despite substantial symptoms of motion sickness. Furthermore, caloric stimulation severe enough to produce nystagmus, dizziness, and nausea had no effect on sympathetic nerve activity measured directly with microneurography. No effect was observed on heart rate, blood pressure, or plasma norepinephrine. Several factors may explain the apparent discordance of these results, but more research is needed before we can define the potential importance of vestibular input to cardiovascular regulation and orthostatic tolerance in humans.

Animals↗