PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Haplorhini”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

New omomyid primates (Haplorhini, Tarsiiformes) from middle Eocene rocks of west-central Hot Springs County, Wyoming.

Three new genera and four new species of omomyid primates constitute the first record of the Primates from upland middle Eocene rocks of Wyoming. One of these, Strigorhysis, gen. nov., possesses broadly basined molars with highly crenulated enamel which probably indicates a good deal of tough vegetable matter in its diet. Each of the new genera could have descended from known Wasatchian or early middle Eocene anaptomorphines: Aycrossia, gen. nov., is a plausible derivative of Tetonius or Chlororhysis; Strigorhysis, gen. nov., is most similar to Absarokius noctivagus; and Gazinius, gen. nov., most closely resembles Absarokius and Anaptomorphus. The anaptomorphines were probably equally as diverse as the better documented omomyines in the middle Eocene, but may have preferred upland environments at the margins of the Tertiary basins of the Rocky Mountain Interior.

Animals↗
PubMed1976

Cladistic relationships among primate higher categories: evidence of the fetal membranes and placenta.

Cladistic analysis of the total ontogenetic pattern of the fetal membranes and placenta in all extant primate superfamilies provides clear evidence of a strepsirhine-haplorhine dichotomy in the order Primates. The suborder Prosimii appears to be a paraphyletic taxon, based on the retention of numerous primitive character states in tarsiers and strepsirhines. Fetal membrane evidence supports the sister group relationship of Tarsiiformes and Anthropoidea in the suborder Haplorhini, based on their possession of shared derived characters. Morphogenetic patterns of the fetal membranes and placenta in haplorhines are consistent with the concept of a monophyletic origin of Anthropoidea from an ancestral tarsilform stock.

Animals↗
PubMed1975

Testosterone metabolism in the skin. A review of its function in androgenetic alopecia, acne vulgaris, and idiopathic hirsutism including recent studies with antiandrogens.

Current concepts of testosterone metabolism in the human skin are reviewed, and the role of dihydrotestosterone in the pathophysiology of androgenetic alopecia, acne vulgaris, and idiopathic hirsutism is discussed. The hypothesis is submitted that a temporary, increased dihydrotestosterone formation at specific skin target sites at different ages causes the normal development of certain sexual characteristics, as well as the androgen-dependent skin disorders. Future treatment of these conditions is discussed in light of recent studies with antiandrogens.

Acne Vulgaris↗
PubMed1977

Pemphigus antibody action on skin explants: kinetics of acantholytic changes and stability of antigens in tissue cultures of normal monkey skin explants.

The pathogenic effect of the intercellular antibodies of pemphigus was studied by using organ culture of monkey skin. Skin explants that were grown on sera with intercellular antibody titers of 320 or greater fixed these antibodies within one day as demonstrated by direct immunofluorescence for IgG. None of the control sera gave such staining patterns. Following the binding of intercellular antibodies, characteristic histologic changes appeared, notably separation of individual epidermal cells and acantholysis. These histologic changes became more marked in two to five days. During this period, the bound antibodies and the intercellular antigens decreased and disappeared. These temporal relationships of immunofluorescence and histologic findings suggest that pemphigus antibodies play a role in the induction of acantholysis.

Acantholysis↗
PubMed1975

Antimyelin antibodies in neurologic diseases. Immunofluorescent demonstration.

Antimyelin binding activity was determined in patients with multiple sclerosis, amyotrophic lateral sclerosis, other neurologic diseases, and normals. There was an increase in the group mean titer of antimyelin antibodies in patients with multiple sclerosis (MS) in acute exacerbation, amyotrophic lateral sclerosis (ALS) and Guillain-Barré syndrome. A lesser degree of binding was found in normals of all ages. There was an increase in the incidence of antimyelin antibodies in the IgM class in patients with ALS and MS. The interaction between human immunoglobulins and myelin seems to be immunologically specific and has the nature of an antigen-antibody reaction.

Acute Disease↗
PubMed1975

Phosphodiesterase inhibitors and cerebral vasospasm.

Experimental cerebral vasospasm was studied in cat and monkey models. In the cat, the basilar artery was exposed by a transclival approach and spasm induced by the application of blood to the vessel. In the monkey, spasm was produced by injecting blood into the subarachnoid space. Vessel size was determined in the cat by direct observation and, in the monkey, by cerebral angiography. Several agents known to alter the synthsis and degradation of cyclic adenosine monophosphate (AMP) were used to modity the vasospasm produced. Isoproterenol (Norisodrine) and aminophyline were effective in reversing cerebral vasospasm when applied topically and when administered parenterally. It is suggested that manipulation of the cyclic AMP pathways may be an effective method of controlling cerebral vasospasm.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗
PubMed1976

Changes in cortical subarachnoid fluid potassium concentrations during hypoxia.

Seventeen rhesus monkeys underwent 20-minute episodes of hypoxia (mean Po2, 18 to 28 mm Hg). In 14 animals that maintained mean blood pressures greater than 60 mm Hg, increases in potassium concentration averaging greater than 1 mEq/liter were observed in the cortical subarachnoid fluid. These changes were reversible with oxygen administration and were usually not associated with morphologic evidence of brain injury. Cisterna magna fluid, sampled in five animals, showed smaller increases in potassium concentration (mean, 0.3 +/- 0.4 mEq/liter). The arteriovenous difference in potassium concentration was consistently positive, suggesting movement of potassium from blood to brain during hypoxia. The amount of potassium accumulation in the cortical subarachnoid fluid was closely related to the severity of the hypoxia. Threshold Po2 levels, below which potassium changes occurred, were estimated at 29 mm Hg for the arterial blood and 20 mm Hg for the jugular venous blood. Massive potassium accumulations in the cortical subarachnoid fluid (greater than 10 mEq/liter) developed in three animals that sustained severe arterial hypotension during hypoxia.

Animals↗
PubMed1976

Physiological aspects of visual perception. I. Functional aspects of visual cortex.

The first part of the Bennett Lecture for 1975 is a description of the dissociation of visual perception in the macaque monkey by ablation of area 17 on the one hand, and of areas 18 and 19 on the other. Bilateral removal of area 17, with careful preservation of a great part of areas 18 and 19, and of the inferior pulvinar, resulted in loss of binocular fixation, loss of visual recognition of still objects, and loss of visuosocial behavior such as grimacing and vocalization. There remained excellent visuospatial orientation and reaching for moving peripheral visual targets. Removal of areas 18 and 19, with isolation of area 17 from the remainder of cortex, was accomplished in two animals and left intact the ability to distinguish and sort out still objects by vision, with intact fixation, and visuosocial behavior. Spatial orientation was then easily confused by movement.

Animals↗
PubMed1976

Physiological aspects of visual perception. II. The subcortical visual direction of behavior.

The second part of the Bennett Lecture for 1975 by Denny-Brown examined the subcortical representation of the dissociation of function described by Denny-Brown and Chambers. Complete removal in the macaque monkey of the corticomesencephalic fibers where they pass from pulvinar to colliculus, and of the colliculus, resulted in the same loss of visual object identification, binocular fixation, and visuosocial behavior that followed removal of area 17. Vision for peripheral movement and spatial orientation ("panoramic vision") remained excellent, with release of catatonia. Conversely, unilateral electrolytic lesions of the mesencephalic tegmentum produced visuospatial distortion, asymmetry of optic righting, and directional difficulties in eye movement (Parinaud syndrome and skew deviation). When bilateral, tegmental lesions produced great constriction of visual field with release of convergence and fixation spasm. Suppression of peripheral attention resulted from perceptual rivalry.

Animals↗
PubMed1976

Cerebral protection by barbiturate anesthesia. Use after middle cerebral artery occlusion in Java monkeys.

Regional cerebral ischemia was produced in 18 Java monkeys by permanent middle cerebral artery (MCA) occlusion. All monkeys were thereafter paralyzed (pancuronium bromide, 0.05 mg/kg/hr) and sedated (diazepam, 0.1 mg/kg/hr) for a 48-hour period. Thirty minutes after MCA occlusion, pentobarbital sodium anesthesia was induced in nine of the monkeys (14 mg/kg) and maintained for 48 hours (7 mg/kg every two hours), with continuous supportive care. After 48 hours, all drugs were discontinued; the monkeys were observed for five days, and then killed. Seven of the control monkeys developed a cerebral infarction, three did not survive past the 48 hours of intensive care, and the other four had a notable neurologic deficit. All pentobarbital monkeys survived the seven days, but four had a cerebral infarction and two of these had a notable neurologic deficit. These differences were statistically significant.

Anesthesia, Inhalation↗
PubMed1976

An explanation of eye movements seen in internuclear ophthalmoplegia.

Recent findings in experiments on monkeys show that a horizontal saccade is made by a pulse-step of neural activity, part of which rises to medial rectus (MR) motoneurons on the fibers of the medial longitudinal fasciculus (MLF). If inhibitory as well as excitatory fibers run in the MLF, then the data show that each MLF must carry both the excitatory and inhibitory activity required for contralateral, horizontal saccades. Therefore, interruption of these fibers removes not only excitation from the ipsilateral MR but inhibition from the contralateral MR. Such a lesion also disturbs the correct relationship between the pulse and the step and creates abnormal saccades. These facts make it possible to explain why, in internuclear ophthalmoplegia, the eye on the side of the lesion adducts slowly and inadequately, while the opposite eye has nystagmus in abduction.

Abducens Nerve↗
PubMed1977

Nervous system effects of cardiac arrest in monkeys. Preservation of vision.

Thirteen juvenile monkeys were taught two visual discrimination tasks. After 12 to 24 hours of food deprivation, ten underwent 14-minute episodes of cardiac arrest. Three served as controls. Five of the ten arrested animals survived and were tested in the discrimination box. All continued to perform color and pattern discrimination tasks with one to eight days' delay. All appeared neurologically intact, while brain pathologic examination after 11 to 64 days' survival showed either intact brains or injury restricted to nuclear structures in the brain stem, cerebellar Purkinje cells, and hippocampus. Five animals died 4 to 36 hours after they were resuscitated. Two required prolonged cardiac massage and, despite return of adequate cardiovascular function, died early. A third animal dislodged its arterial catheter and exsanguinated. The remaining two animals, who received infusions of glucose just prior to arrest, developed widespread fasciculations and myoclonic seizures. They became decerebrate and opisthotonic and were killed after 10 and 36 hours. Their brains showed mild edema and widespread necrosis of cortex and basal ganglia. Thus, food-deprived monkeys tolerate 14 minutes of circulatory arrest well and show minimal neurologic and pathologic changes, while administration of glucose just before arrest markedly augments the severity of brain injury and alters its distribution.

Animals↗
PubMed1977

Evoked potential in neglect.

The evoked potential was studied in Macaca speciosa before and after they received a lesion inducing neglect. Significant evoked potential changes associated with neglect were seen only in late components (N2, P3). These observations support the hypothesis of the arousal-attention mechanism of neglect.

Animals↗
PubMed1977

Pharmacological prophylaxis in the kindling model of epilepsy.

Review of antiepileptic drug assessment to date by means of the kindling model of epilepsy suggests that it fills a gap that is evident in standard screening methods such as maximum electroshock or pentylenetetrazol screening tests. However, in order to obtain a comprehensive profile of antiepileptic drugs regarding prophylaxis of developing seizures and treatment of well-established seizures through the kindling preparation, it is desirable to have the following: (1) standardization of kindling techniques, (2) examination of drug effects on developing as opposed to developed seizures, (3) use of a variety of animal species, involving different functional brain sites, and (4) monitoring of plasma levels of the drug administered. It is envisaged that judicious use of the kindling preparation might also enable us to gain some insight into the mechanisms by which drugs produce their prophylactic or therapeutic effect.

Amygdala↗
PubMed1978

Elevations of hemopexin levels in neuromuscular disease.

Hemopexin, a serum glycoprotein that binds free heme and transports it to hepatic parenchymal cells, has been measured by radial immunodiffusion. We have confirmed elevation of serum hemopexin concentration in Duchenne's muscular dystrophy patients and carries, and demonstrated elevations in dermatomyositis/polymyositis and myasthenia gravis, but not in amyotrophic lateral sclerosis. In monkeys, elevations of hemopexin levels were specifically induced by hematin injections, muscle-crush, or myoglobin injections. Myoglobin leakage is the likely explanation of hemopexin level elevation in Duchenne's dystrophy patients and carriers and in dermatomyositis/polymyositis. In myasthenia gravis there might be a slight myoglobin leakage not heretofore suspected; or, the elevation of hemopexin levels might be a new reflection of a dysimmune state in myasthenia gravis, and perhaps as such is a further incrementing factor in dermatomyositis/polymyositis. Hemopexin, presumably as a longer-phase reactant, is sometimes an index of neuromuscular disease when other data are negative or equivocal.

Animals↗
PubMed1979

Spinal cord evaluation by cortical evoked responses.

In ten monkeys, selective segmental lesions of the dorsal columns at the upper thoracic and middle cervical levels resulted in almost total attenuation of the cortical evoked potential responses to peripheral nerve stimulation. Conversely isolated segmental dorsal column preservation showed intact transmission of the evoked responses at rostral spinal cord, nucleus ventralis posterior lateralis, and cortical levels. Responses recorded from the intralaminar thalamic nuclei in the region of nucleus centrum medianum were unaffected by dorsal column ablation, but were markedly attenuated following bilateral ventral column ablation.

Animals↗