Plasma melatonin levels were measured in male Japanese quail exposed to lighting schedules consisting of combinations of bright light (2000 or 1500 lx), darkness, or dim light (2 lx) or to constant dim light. Melatonin levels in dim light were dependent upon the relative intensity of accompanying phases, being significantly higher when dim light was subjective night than when it was subjective day. There was no significant melatonin rhythm in constant dim light, even on the first day of constant dim light exposure. Melatonin levels were intermediate when dim light was accompanied by both bright light and darkness. These results indicate that melatonin secretion in birds does not depend solely on light intensity. Furthermore, these results suggest that the avian circadian system may be more sensitive to environmental cues than its mammalian counterpart.

Animals↗

PubMed1989

5-(1-piperazinyl)-1H-1,2,4-triazol-3-amines as antihypertensive agents.

A series of 5-(1-piperazinyl)-1H-1,2,4-triazol-3-amines was synthesized and screened for antihypertensive and diuretic activity in spontaneously hypertensive rats (SHR). One compound, 5-[4-[(3-chlorophenyl)methyl]-1-piperazinyl]-1H-1,2,4-triazol-3-am ine (8), was selected to define the mechanism of its antihypertensive activity. Studies in SHR suggest ganglionic blocking activity. Short-lived antihypertensive activity was observed in conscious renal hypertensive dogs.

Animals↗

PubMed1988

[Vascular cause of hemianopsia].

Hemianopsia of vascular origin can be caused by diseases in the carotid circulation (optic tract, proximal third of the optic radiation), as well as in the vertebrobasilar arterial system (middle and distal thirds of the optic tract, striate area/calcarina). Hemianopsia of ischemic origin must be differentiated from hemianopia in the presence of an enlarging aneurysm, a space-occupying intracranial lesion (hemorrhage, neoplasia), and inflammatory disease, occasionally in metabolic disorders. To detect the exact cause of a hemianopia in a given patient, recording of the patient's precise history and clinical-neurological, clinical-ophthalmological, and clinical-internal examinations are mandatory, as well as additional diagnostic procedures. Of these, the most important are neurovascular ultrasound examinations (extracranial, transcranial and B-mode/duplex Doppler examination), CT and MRI scans, and cardiological examination with echocardiography. The choice of these additional and costly examinations and their sequence in the diagnostic work-up in a given patient has to be adapted to the patient.

Aged↗

PubMed1988

Photostimulation of Japanese quail by dim light depends upon photophase contrast, not light intensity.

Three experiments were conducted to determine whether dim light is interpreted by Japanese quail as subjective day or night, and whether this interpretation depends upon absolute light intensity. Birds were exposed to 24-h days consisting of either bright light (2500-3000 lx) with dim light (0.5-5 lx) or dim light with darkness. Locomotor activity was higher in the brighter photophase, whether it was bright light or dim light, indicating that the birds interpreted the brighter phase as daytime. Dim light produced daytime activity levels when paired with darkness, but it produced nighttime activity when paired with bright light, indicating that activity rhythms are determined by relative not absolute light intensity. Similarly, photostimulation, as measured by growth of the cloacal protrusion area (CPA), depended upon photic context, not absolute light intensity. CPA growth occurred when birds were exposed to 16 h of dim light with 8 h of darkness (16dm:8dk) but not when exposed to 10 h of bright light with 14 h of dim light (10bt:14dm). Constant dim light was stimulatory regardless of previous dim light context. Photostimulation appears to depend upon subjective interpretations of day and night rather than solely upon light intensity.

Animals↗

PubMed1987

Partial duodenal obstruction secondary to Meckel's diverticulum.

Explore the source record for details and available documents.

Aged↗

PubMed1986

Primary feather molt and serum luteinizing hormone concentration in chukar partridge (Alectoris chukar) during a photoperiodically induced molt with or without fasting.

In two experiments, 135 adult chukar partridge of two genetic lines, one selected for high egg production and a random-bred control line, were induced to molt by reducing photoperiod from 16 hr light/day to 8 hr light/day on Day 0. In Experiment 1, feed was removed from approximately half the birds on Day 0 and returned on Day 7. Birds in Experiment 2 were not fasted. Photoperiod was increased to 16 hr light/day on Day 56. Primary feather molt scores, body weights, and, in Experiment 2, serum luteinizing hormone (LH) levels were monitored weekly through Day 85. Prior to the short day period, birds selected for high egg production and females had lower molt scores than controls or males, respectively. Fasting had no effect on molt scores, egg production, or body weights (except during the fasting period). Selected-line birds returned to lay approximately 3 days earlier and laid approximately 16 more eggs during the second production period than controls. Six days before photoperiod was reduced, immunoreactive serum LH levels were 5 to 8 ng/ml; they declined during short days to about 4 ng/ml. Within 8 days after relighting, LH levels increased to approximately 33 ng/ml in males and 18 ng/ml in females. Luteinizing hormone levels remained elevated in males throughout the subsequent 4 weeks but declined in females as egg production resumed.

Animals↗

PubMed1985

Treatment of unresectable or metastatic osteosarcoma with cisplatin or cisplatin-doxorubicin.

Responses and toxicity after treatment with cisplatin and cisplatin-doxorubicin were compared in two groups of patients with unresectable or metastatic osteosarcoma. Complete or partial responses developed in 3 of 18 individuals treated with cisplatin, and in 5 of 19 after the two-drug combination. Hematologic and gastrointestinal complications were more frequent and severe in patients who received both agents. The combined use of cisplatin and doxorubicin is justified for patients with unresectable or metastatic osteosarcoma at diagnosis because of the potential therapeutic benefits for these individuals.

Adolescent↗