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At least 19 recordsLinked to original sources
PubMedDate not supplied

Ethnopharmacology of rhinoceros horn. II: Antipyretic effects of prescriptions containing rhinoceros horn or water buffalo horn.

Aqueous extracts of rhinoceros horn or water buffalo horn demonstrated significant antipyretic action at 2.5 g/ml i.p. (1 ml/animal) in rats with hyperthermia induced by subcutaneous injection of turpentine oil. Qingying Decoction, a classic compound prescription composed of rhinoceros horn and eight herbs, showed significant antipyretic action at dosages equivalent to 0.5 g/ml of rhinoceros horn extract. Comparable action was obtained by Qingying Decoction prepared with water buffalo horn. It is suggested that water buffalo horn can be used as a substitute for rhinoceros horn in treating hyperthermia, especially when prepared with other herbal materials according to the principles of compound prescriptions of Chinese medicine.

Animals↗
PubMed1979

Trichilemmal horn: cutaneous horn showing trichilemmal keratinization.

A unique and distinctive clinicopathological entity occurred in nineteen patients who ranged in age from 16 to 72 (median 50) years. Clinically, these were solitary cutaneous horns. Nine were on the limbs, four on the back, two on the face, three on the scalp, and in one the site was not known; the median duration was 2 years. Histologically, there was a benign picture with a protrusion of massive horn and trichilemmal keratinization at the base. This tumour, which I have named trichilemmal horn, must be differentiated from other lesions that show trichilemmal keratinization (trichilemmal cyst, proliferating trichilemmal cyst, keratoacanthoma) and from other cutaneous horns, including trichilemmomal horn (cutaneous horn overlying trichilemmoma).

Adolescent↗
PubMed1979

Antigenic similarity between squamous cell carcinoma of horn (horn cancer) and normal bovine foetal tissues.

Normal bovine foetal (liver and skin) and horn cancer tissue antigens were examined using double diffusion agar gel precipitation and immuno-electrophoretic tests to detect any cross reactivity among them. Rabbit horn cancer antisera absorbed with normal bovine liver, skin and horn core epithelium antigens, when tested with foetal skin and liver (4 to 6 months of gestation), revealed the presence of 2 foetal antigens in horn cancer. Immuno-chemically 2 of the horn cancer antigens were found to be identical to the bovine foetal antigens.

Animals↗
PubMed1978

Sensitization and habituation of dorsal horn cells in cats.

1. Extracellular recordings were obtained from spinal dorsal horn cells in acutely spinalized cats anaesthetized with sodium pentobarbitone. The dorsal horn cells studied responded to ipsilateral tactile stimulation of the central pad of the hind foot. Eleven short latency dorsal horn cells driven by electrical stimulation of the foot pad were studied intensively; these short latency dorsal horn cells all discharged within 1.5 msec of the arrival of an afferent volley at the dorsal root entry zone. Electrode tip sites were histologically verified to lie near the medial border of the dorsal horn in the seventh lumbar segment, in Rexed's laminae III and IV. 2. Electrical stimulation of the foot pad not only activated the dorsal horn cells studied, but also produced a reflex discharge which was monitored by recording from the ipsilateral first sacral ventral root, which had been sectioned intradurally and mounted on bipolar recording electrodes. Repeated stimulation of the foot pad at moderate intensities and frequencies (e.g. three times threshold for the ventral root response at 5 Hz) typically produced a transitory increase in the magnitude of the reflex discharge (sensitization) followed by a marked waning of the reflex magnitude (habituation). Within a few minutes following cessation of stimulation, the reflex magnitude returned to its prestimulation value. During repeated bouts of five hundred stimuli each, at frequencies from 1.0 to 10.0 Hz, and intensities 1.5-10.0 times reflex threshold, the firing pattern of a short latency dorsal horn cell was monitored along with the magnitude of the ventral root response. Changes in response patterns of the dorsal horn cells were compared to those of the reflex discharges. 3. The short latency dorsal horn cells fell into two distinct patterns of response. The firing pattern of six dorsal horn cells paralleled the response pattern of the reflex discharge; when the reflex increased in magnitude, each of these dorsal horn cells increased in number of responses per stimulus; when the reflex discharge decreased in magnitude, each of these dorsal horn cells decreased the number of responses per stimulus. These dorsal horn cells were characterized by the following: intermediate thresholds to tactile stimulation, comparable to that of the reflex discharge itself; relatively low numbers of responses per stimulus (mean: 1.3/stimulus); low spontaneous activity rates (once per 10 sec or less). 4. The firing patterns of the other class of short latency dorsal horn cells did not parallel the response pattern of the reflex discharge; these showed only a rather rapid, though moderate, decrease in responses per stimulus over the entire range of intensities and frequencies tested. These five dorsal horn cells were characterized by the following: thresholds of tactile stimulation considerably below that of the reflex discharge itself; bursts of responses following each stimulation (mean: 7...

Action Potentials↗
PubMed1992

Synaptic activation of dorsal horn neurons by selective C-fibre excitation with capsaicin in the mouse spinal cord in vitro.

Low doses (0.2-0.8 microM) of capsaicin were used to achieve selective excitation of C-fibres and the consequent synaptic activation of dorsal horn neurons (laminae I-VI) in the spinal cord of the 12-20-day-old mouse, maintained in vitro. Most dorsal horn cells were activated by application of capsaicin to dorsal root ganglia. The response consisted of a long-lasting membrane depolarization with increased regenerative (synaptic) activity in 79% of the cells, and in a further 7% only an increased synaptic activity was evoked. These effects of capsaicin were completely blocked by removing extracellular calcium ions from the superfusate to the spinal cord, or by the addition of 1 microM tetrodotoxin, suggesting a presynaptic origin of the capsaicin action. Only 67% of cells excited by capsaicin were sensitive to exogenous substance P. The excitatory amino acid antagonists, kynurenic acid (50-100 microM) or (-)-2-amino-5-phosphonovaleric acid (10-20 microM) completely blocked the capsaicin-evoked response in deep dorsal horn cells, indicating the involvement of excitatory amino acid receptors in the synaptic pathway. However, in superficial dorsal horn neurons these antagonists attenuated, but never completely abolished, the capsaicin-evoked depolarization. The kynurenic acid-resistant component of the capsaicin-evoked excitation in superficial dorsal horn cells suggests the involvement of non-amino acid excitatory transmitters--possibly neuropeptides--in the synaptic transmission. Activation of primary afferents by high-intensity electrical stimulation of the dorsal roots induced a prolonged (0.5-3 s) postsynaptic excitation in the majority of deep dorsal horn cells. The duration of the synaptic response was significantly reduced by (-)-2-amino-5-phosphonovaleric acid. Following repeated application of capsaicin, desensitization of the capsaicin-evoked synaptic activation of dorsal horn cells occurred. This effect was paralleled with the loss of the prolonged (-)-2-amino-5-phosphonovaleric acid-sensitive phase of the excitatory postsynaptic potential evoked by the high-intensity electrical stimulation of dorsal roots. This observation suggested that activation of the N-methyl-D-aspartate receptors in the dorsal horn can be activated by small-calibre capsaicin-sensitive fibres. In summary, our data suggest that the selective activation of C-fibre afferents with capsaicin produces synaptic activity in the dorsal horn which has a strong excitatory amino acid component as well as a non-excitatory amino acid, possibly peptidergic, component.

Animals↗
PubMed1978

The effect of ligation or separation between the intrauterine device horn and adjacent ovary on implantation in the hamster.

The purpose of this study was to determine whether the luteolytic action of an intrauterine device (IUD) is suppressed following interruption of the continuity between the IUD uterine horn and the adjacent ovary. After several estrous cycles, a silk IUD was placed in the cervical end of one uterine horn of adult hamsters. The animals were then mated, and on day 6 of gestation the ovary and oviduct contralateral to the IUD were removed and a ligature was placed between the IUD horn and the adjacent ovary. The hamsters were killed on day 9 or day 13 of gestation. Fetal development in the contralateral horn was suppressed on day 13 but not on day 9. In the second study the animals were treated as in the first study except that the communication between the IUD horn and the adjacent ovary was severed completely. The hamsters were killed on day 9 or day 13. On both days 9 and 13 normal fetal development was observed in the control horn; no implantation sites were present in the IUD side. In the control (non-IUD) animals of each study, normal fetuses were present in both uterine horns. The study demonstrates that luteolysis does not occur if there is complete disruption of the communication between the IUD horn and ovary. The study also demonstrates that, since implantation did not occur in the IUD horn with a normally functioning ipsilateral ovary, the luteolytic action of the device is not the prime factor in suppressing implantation in the hamster.

Animals↗
PubMed1990

Changes of substance P-like immunoreactivity in the dorsal horn are associated with the 'phasic' behavioral response to a formalin stimulus.

Substance P (SP) has been proposed as a nociceptive transmitter/modulator in the dorsal horn of the spinal cord. Formalin used as a nociceptive stimulus has been shown to increase, in a biphasic manner, the amount of immunoreactive SP in the dorsal horn. The time course of the changes in substance P-like immunoreactivity (SPLI) caused by formalin is similar to both the electrical activity of dorsal horn neurons and licking behaviors. The administration of morphine reduces stereotypic behaviors caused by a formalin injection but actually increases the amount of SPLI in the dorsal horn. Therefore, the extent to which SP in the dorsal horn is involved with nociception as a result of formalin remains uncertain. To test the involvement of SP with chemogenic nociception, we utilized lidocaine to block afferent activity prior to an injection of formalin and studied the time course of behaviors and SPLI changes in the dorsal horn. Our results showed that formalin produced two distinct phases of nociceptive behaviors as measured by stereotypic licking of the injected paw: an acute 'phasic' response followed by a longer-lasting 'subacute' or 'tonic' response. Lidocaine reduced both phases of stereotypic behaviors, but only reduced the first increase of SPLI in the dorsal horn. These results suggested a direct involvement of SPLI in the dorsal horn with only 'phasic' behavioral responses to a formalin stimulus.

Animals↗
PubMed1991

Signalling of a step-like intensity change of noxious mechanical stimuli by dorsal horn neurones in the rat spinal cord.

1. Single-unit extracellular recordings were made from thirty-one dorsal horn neurones in the sacral spinal cord of barbiturate-anaesthetized rats. Each neurone was tested with four noxious mechanical pinches applied to its receptive field on the tail. Each pinch lasted 120 s, with a step-like change in intensity after 60 s. In two pinches the step increased the intensity, from 4 to 6 N or from 6 to 8 N, and in two the step decreased the intensity, from 8 to 6 N or from 6 to 4 N. 2. The ability of the neurones to signal these step changes in intensity was examined. Five neurones with an exclusively low-threshold afferent input (class 1) were tested, and found to fire only briefly at the start of the 120 s stimulus. Neurones with a high-threshold input (nociceptive neurones), either exclusively (class 3; n = 10) or in addition to a low-threshold input (class 2: n = 16), responded throughout the 120 s stimuli. 3. Nociceptive dorsal horn neurones have been divided into two groups of 'good' and 'poor' encoders on the basis of their response to the step changes in intensity. 4. 'Good' encoders (n = 13) were neurones signalling both a step increase and a step decrease in intensity, of which seven were class 2 and six class 3, five recorded in the superficial dorsal horn and eight in the deep dorsal horn. 5. 'Poor' encoders (n = 13) were neurones which failed to signal one or both of the step changes in intensity, of which nine were class 2 and four class 3, three recorded in the superficial dorsal horn and ten in the deep dorsal horn. 6. These results demonstrate that neurones with similar input properties and location are not necessarily a homogeneous group in terms of their processing of nociceptive stimuli. Moreover, they suggest that subgroups of both class 2 and class 3 and of superficial and deep dorsal horn neurones contribute to the different components of a nociceptive response. 7. We propose that the output and projection target of a particular dorsal horn neurone are more important than its afferent input in determining its role in nociceptive processing.

Animals↗
PubMed1976

The response of the brachial ventral horn or Xenopus laevis to forelimb amputation during development.

The normal development of the brachial ventral horn of the frog Xenopus laevis and the response of the brachial ventral horn to complete forelimb extirpation at five developmental stages were assessed histologically. Differentiation of brachial ventral horn neurons occurred in pre-metamorphic tadpoles between stages 52/53 and 57. Mean cell number in the brachial ventral horn reached a peak of 2576 (S.E.M. equals +/- 269, N equals 2) per side of the spinal cord at stage 55 and decreased to 1070 (S.E.M. equals +/- 35, n equals 7) by the end of metamorphosis. Cell degeneration was presumed to be the mode of cell loss since it was most prevalent during the period of rapid decrease in cell numbers. The response of the ventral horn to forelimb removal varied with the stage of the animal at amputation. Following amputation at stage 52/53 or 54 the ipsilateral ventral horn neurons appeared less differentiated than those on the control side and a rapid cell loss of about 80% occurred on the operated side. These effects occurred more rapidly after ablation at stage 54 than at stage 52/53. Amputation at stage 58, 61, or 66 caused chromatolysis in the ventral horn, a period of relative cell excess on the operated side, and a delayed neuronal loss of 32-66%. It was concluded that excess cell degeneration accounted for cell loss and that suppression of normal neuronal degeneration caused the relative cell excess on the operated side. The data indicate that the brachial ventral horn was indifferent to the periphery before stage 54, was quickly affected by limb removal between stages 54 and 58, and by stage 58 had entered a phase in which a delay preceded cell death. No forelimb regeneration occurred.

Age Factors↗
PubMedDate not supplied

The large temporal horn: MR analysis in developmental brain anomalies versus hydrocephalus.

PURPOSE: To utilize MR to delineate the morphologic abnormalities of the temporal horn and adjacent structures in patients with congenital brain anomalies and to differentiate these findings from the temporal horn alterations in obstructive hydrocephalus. PATIENTS AND METHODS: Thirty-six patients were included in this retrospective study, including eight with agenesis of the corpus callosum (ACC), four with lissencephaly (lis), four with lobar holoprosencephaly (holo), as well as 20 with isolated obstructive hydrocephalus due to tumor (17 patients) or aqueductal stenosis (three patients). Twenty patients with normal scans were included as controls. RESULTS: Coronal plane image analysis showed that 75% of patients with brain anomalies had enlargement of the temporal horns, most prominently involving the inferolateral aspects of the ventricle (8/8 ACC, 4/4 lis, 0/4 holo). Hippocampal formations were small in 62% (6/8 ACC, 3/4 lis, 1/4 holo). An abnormal, vertical orientation (incomplete inversion) of the hippocampal formations was observed in 82% (8/8 ACC, 4/4 lis, 1/4 holo). Focal thinning of the white matter lateral to the temporal horn was seen in 50% (8/8 ACC, 0/4 lis, 0/4 holo). All patients with isolated obstructive hydrocephalus showed enlargement of the temporal horns, most pronounced in the superior-lateral region. Hippocampal formations showed normal, horizontal orientation (complete inversion) and were of normal size in 17 of 20 patients; the only exceptions included patients with severe hydrocephalus where the hippocampi were flattened along the inferior margin of the temporal horn. Temporal lobe white matter was normal in the 17 patients with mild or moderate hydrocephalus: diffuse white matter thinning inferolaterally was observed in the three patients with severe hydrocephalus. Distinct differences were present in the morphology of the temporal horn and surrounding brain in congenital brain disorders compared with those in patients with hydrocephalic. The anomalous brains showed enlargement as a result of incomplete development, and the hydrocephalic brains showed enlargement as a result of increased intraventricular pressure. CONCLUSION: Temporal horn enlargement in lissencephaly and agenesis of the corpus callosum should not be misinterpreted as hydrocephalus. Analysis of temporal lobe morphology will allow differentiation if doubt exists.

Adolescent↗
PubMed1992

Dilatation of the temporal horn in subarachnoid haemorrhage.

CT studies of 50 patients with spontaneous subarachnoid haemorrhage (SAH) and 100 randomly selected patients were reviewed with regard to the size of the frontal and temporal horns of the lateral ventricles. The temporal horn was classified into four grades, based on the size of its posterior portion at the level of the midbrain. The horn was clearly visible in 66% of patients with SAH, but in only 2% of controls. In the SAH group, the temporal horn tended to dilate sooner than the frontal horn after haemorrhage and could be seen clearly in a larger proportion of patients. Thus, assessment of the size of the temporal horn appears to be a simple and sensitive method for assessing ventricular dilatation. In addition, dilatation of the temporal horn may prove to be an important indirect sign suggesting SAH in patients in whom no high density clot is seen on CT.

Adult↗
PubMed1992

Responses of motor units during the hind limb flexion withdrawal reflex evoked by noxious skin heating: phasic and prolonged suppression by midbrain stimulation and comparison with simultaneously recorded dorsal horn units.

In rats anesthetized with sodium pentobarbital, we quantitatively analyzed descending modulation from the midbrain of a nociceptive flexion withdrawal reflex and responses of associated spinal neurons. We monitored the isometric force of hind limb withdrawal elicited by noxious heat stimuli (42-54 degrees C, 10 sec) on the hind paw. In one series of experiments, single-fiber EMG electrodes recorded responses of single muscle fibers (i.e., motor units) in biceps femoris during the hind limb withdrawal, without and during electrical stimulation in the midbrain periaqueductal gray (PAG) or lateral midbrain reticular formation (LRF). In a second series, responses of single lumbar dorsal horn neurons were also recorded simultaneously. Withdrawal force and associated motor unit responses were suppressed for prolonged periods (4 to greater than 60 min) following the initial episode of PAG or LRF stimulation in 40% of the rats, while they were suppressed phasically (i.e., only during brain stimulation) in the remainder. Motor unit responses increased in a graded fashion with increasing skin stimulus temperature from threshold (45 degrees C) to 54 degrees C. During PAG stimulation, the slope of the rate coding function was reduced with no change in threshold temperature. During LRF stimulation the rate coding function was shifted toward higher temperatures with increased threshold (47 degrees C). In 14 experiments 43 paired recordings were made from a dorsal horn and a motor unit during hind limb withdrawals. Mean latency to onset and peak of the heat-evoked response was shorter for dorsal horn compared to motor units. In 6/14 rats withdrawal force and motor unit responses were significantly suppressed for more than 8 min following mechanical placement of the stimulating electrodes and/or the initial episode of midbrain stimulation, while the simultaneously recorded dorsal horn unit responses remained constant. Following supplemental administration of pentobarbital (10-30 mg/kg i.v.), withdrawals and motor unit responses to heat were suppressed while dorsal horn unit responses were unchanged or enhanced. Also, in 12/42 cases, withdrawals and motor unit responses decremented markedly during the initial 3 trials of heat, while simultaneously recorded dorsal horn unit responses remained stable. These results indicate that the withdrawal reflex and associated motor units can be markedly suppressed in the absence of concomitant changes in responsiveness of dorsal horn neurons, and are discussed in terms of the neurocircuitry of spinal flexor reflexes and their descending modulation.

Animals↗
PubMed1992

Differential influence of naloxone on the responses of nociceptive neurons in the superficial versus the deeper dorsal horn of the medulla in the rat.

Naloxone (200 micrograms/kg, i.v.) reduced the noxious thermal stimuli-evoked responses of 16/25 nociceptive neurons in the superficial laminae whereas it enhanced the responses of 6/10 nociceptive neurons in the deeper dorsal horn. However, a different picture emerged when selectivity of neuronal responsivity (nocireceptive or multireceptive) was considered. In the superficial dorsal horn, naloxone reduced the responses of the majority of (15/18) selectively nocireceptive neurons. The reduction in responses became apparent within 60 sec following naloxone administration and returned to control level within 48 min. In contrast, the responses of the majority of multireceptive neurons in the superficial (6/7), or the deeper (6/10) dorsal horn, were enhanced. The excitatory action in the superficial dorsal horn persisted for only 6-15 min, whereas it persisted for 40-70 min in the deeper dorsal horn. The firing of the majority of cold-receptive neurons (6/8) in the superficial dorsal horn was not altered. These effects were stereoselective since (+)-naloxone, the inactive isomer of naloxone, did not affect the responses of 14/16 nociceptive neurons. It is concluded that naloxone differentially, and selectively, affects the firing of nociceptive neurons in the superficial versus the deeper dorsal horn, and the firing of selectively nocireceptive versus multireceptive neurons. The relevance of these findings to the behavioral effects of naloxone, hyperalgesia and analgesia, is discussed.

Animals↗
PubMed1991

Horn fly (Diptera: Muscidae) insecticide resistance in Kentucky and Arkansas.

The effect of previous insecticide use patterns for horn fly control on the susceptibility spectrum of horn fly (Haematobia irritans [L.]) populations from Kentucky and Arkansas is described. Populations of horn flies from both states were tested with three pyrethroids (cyhalothrin, cypermethrin, and permethrin), three organophosphates (diazinon, pirimiphos methyl, and tetrachlorvinphos), and a chlorinated hydrocarbon (methoxychlor). Dose-mortality data indicated insecticide resistance in Arkansas and Kentucky. Two permethrin-resistant horn fly populations in Kentucky that did not have a history of exposure to methoxychlor were cross-resistant to this chlorinated hydrocarbon. Horn fly populations from both states with a history of at least three consecutive years of exposure to various pyrethroid ear tags were subsequently exposed to cattle tagged with cyhalothrin-impregnated ear tags for 15-16 wk. Such exposure resulted in a decrease in susceptibility to this pyrethroid (ranging from approximately 30 to greater than 100-fold) when compared with levels before treatment. Horn fly populations from Arkansas resistant to cyhalothrin (as a result of exposure to cyhalothrin ear tags) were cross-resistant to pirimiphos methyl. Seasonal exposure of an Arkansas and Kentucky horn fly population to cattle with ear tags impregnated with pirimiphos methyl resulted in a significant decrease in susceptibility to this organophosphate.

Animals↗
PubMed1991

Interactive response of the horn fly (Diptera: Muscidae) and selected breeds of beef cattle.

Statistically significant differences were observed in the population density of the horn fly, Haematobia irritans irritans (L.), on different breeds of beef cattle. The European breed Chianina had a population density of horn flies generally less than or equal to 50% than that of the British cattle breeds (Angus, Hereford, Polled Hereford, and Red Poll) and another European breed (Charolais). Generally, no significant difference existed among numbers of horn flies on Hereford, Polled Hereford, and Red Poll cows in 1988 or among Angus, Hereford, Polled Hereford, and Red Poll cows in 1989. Factors other than color appeared to be involved in the selective process between the horn fly and its host. Population densities on two white European breeds (Charolais and Chianina) were significantly different on all weekly intervals except for 4 wk in both 1988 and 1989. No significant difference existed among Charolais and British breeds except during 4 wk in 1988 and 3 wk in 1989. When weaning weights of all calves were adjusted for the effects of age to 205 d, sex of calf, and age of dam, the indirect effect of the horn fly on weaning weight showed a significant linear regression. Each 100 flies per cow caused a reduction of 8.1 kg in calf weaning weight. Cows within each breed with low numbers of horn flies weaned significantly heavier calves than cows with higher numbers of horn flies.

Animals↗