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Biomedical subjects

J Haller

Publications and source records attributed to J Haller.

At least 91 records · Page 5Linked to original sources
PubMed1995

Do alpha-2 adrenoceptors modify coping strategies in rats?

Previous research has shown that resident rats treated with alpha 2 adrenoceptor blockers display a modified aggressive response towards intruding animals. In the present study we report data on the behavioral changes induced by alpha 2 adrenoceptor blockers in intruder animals. In experiments 1 and 2 intruders smaller in body weight than the residents were treated with 0.0, 0.5, and 1.0 mg/kg CH-38083 and idazoxan, respectively; in experiment 3 weight matched intruders were injected with 1 mg/kg CH-38083 or idazoxan. The treatment of smaller intruders did not change the behavior of residents. In contrast, weight-matched intruders injected with alpha 2 adrenoceptor blockers elicited increased aggression in residents. Social behaviors, exploration and offensive aggression showed insignificant variation in intruders. Defensive behaviors, in contrast, showed major changes: in experiments 1 and 2 a dose-dependent decrease in immobility and a dose-dependent increase in defensive upright was noticed. In experiment 3, high scores of defensive upright were apparent, precluding detection of drug-induced changes. However, when the last 5 min of the encounter were analysed separately, results similar to the first two experiments were observed. Significant negative correlations were found between immobility and defensive upright scores. The results suggest that alpha 2 adrenoceptor blockers induce a shift from a passive (immobility) towards a more active (defensive upright) coping style. These and previous data show that alpha 2 adrenoceptor blockers, other than yohimbine, seem to exert a behavior-activating effect in rats.

Adaptation, Psychological↗
PubMed1995

Alpha-2 adrenoceptor blockade and the response to intruder aggression in Long-Evans rats.

Alpha-2 adrenoceptor antagonists remove the presynaptic negative feed-back control of norepinephrine release, by this enhancing the naturally occurring adrenergic activation. Male Long-Evans rats were injected with 1 mg/kg CH-38083, an alpha 2 adrenoceptor blocker. Twenty minutes later a size matched Wistar or Long-Evans opponent, respectively, was introduced in their home cage for 15 min (the Wistar strain is more aggressive than the Long-Evans in these circumstances). The treatment increased the number of biting attacks several folds in both situations. The correlations existing between the behavior of the intruder and the aggressiveness of the resident (treated) rat led to the conclusion that the catecholaminergic treatment increased the sensitivity of the animals to the behavioral actions of the intruder. The treated animals responded in an exaggerated fashion compared to their saline treated counterparts. An increase in the corticosterone response of the treated rats paralleled the increase in attack frequency, and seemed not to depend on the challenge received from the intruder.

Adrenergic alpha-2 Receptor Antagonists↗
PubMed1995

Catecholamine stimulation and the response to behavioral challenge in Wistar rats.

Male Wistar rats were injected with CH-38083, an alpha 2-adrenoceptor blocker, after which they were challenged by a size-matched Wistar or Long-Evans opponent. In residents facing low-aggression opponents, the alpha 2-adrenoceptor blockade significantly reduced aggressiveness, whereas in those facing highly aggressive opponents the treatment significantly increased aggression scores compared to saline-treated controls, irrespective of the strain of the intruder. When the animals were treated with CH-38083, the frequency of biting attacks correlated significantly with the aggressiveness of the opponent in residents fighting with Wistar and Long-Evans rats. Similar correlations were not found in control (saline-injected) rats. The results suggest that the catecholaminergic activation caused by the alpha 2 receptor antagonist elicits a more efficient adaptation to the behavioral actions of the opponent. Plasma corticosterone levels were not influenced by the treatment, but this variable seemed to be correlated with the defensive behavior performed by the intruder.

Adrenergic alpha-2 Receptor Antagonists↗
PubMed1995

Biochemical background for an analysis of cost-benefit interrelations in aggression.

Aggression consumes important amounts of energy (e.g., in fish the effort of "routine" social life may be as costly as life-long forced swimming at moderate speeds). In fish the amount of energy spent and the metabolic compartment mobilized seem to depend on the length of cohabitation, the number of contestants and the result of the fight. In mammals, metabolic preparations for fights were shown. The fights cause elevations of both body temperature and metabolic rate, as well as important changes in carbohydrate and lipid metabolism. There are evidences which show that the energetic aspects of aggressive behavior have a significant impact on the behavioral tactics and survival chances in free living animals. The relevance of these studies to game theoretical analyses and to practical aspects of the aggression-energy metabolism interrelationship are also outlined. Although many details of the phenomenon are known, important issues have to be clarified, among them the possible neuroendocrinologic co-regulation of this behavior and of its energetic background.

Aggression↗
PubMed1995

Hormonal and metabolic responses during psychosocial stimulation in aggressive and nonaggressive rats.

The physiological effects of a psychosocial threat (the mere presence of a potentially antagonist individual in the home cage) were studied in aggressive and nonaggressive rats. Aggressive animals spent a significantly longer time with the investigation of the opponent compared with the nonaggressive group. An increase in plasma epinephrine and corticosterone was noticed both in aggressive and nonaggressive animals. Ir beta-endorphin increased significantly only in nonfighters. Glycemia was slightly larger in nonaggressives, while lactaemia increased in both groups. The possibility is discussed that differences in psychosocial stress response may be involved in the regulation of behavior in a real encounter.

Adrenocorticotropic Hormone↗
PubMed1995

Serum zinc and serum lipid profiles in 778 adults.

There has been increasing use of high-dosage zinc supplementation in the population, in particular as a potential treatment for age-related macular degeneration. We examined the relationship between fasting serum zinc and serum lipid levels in 778 adults, aged 22 to 80 years, who were control subjects in a multicenter, clinic-based case-control study. The samples were taken during 1987 to 1990, a time when vitamin/mineral supplementation was becoming increasingly common. We found that higher serum zinc levels, most notably those above the highest quintile, were associated with higher levels of total serum cholesterol, low-density-lipoprotein cholesterol, and triglycerides. No significant trend was noted for high-density-lipoprotein cholesterol. Previous studies demonstrated that high-dosage zinc supplements raise serum zinc levels. The possibility that use of such supplements can adversely affect serum lipid profiles suggests that chronic ingestion of such supplements should not be done without adequate medical supervision.

Adult↗
PubMed1995

Vitamin supplementation for 1 year improves mood.

The possibility that the taking of vitamin supplements may influence mood was explored. One hundred and twenty-nine young healthy adults took either 10 times the recommended daily dose of 9 vitamins, or a placebo, under a double-blind procedure, for a year. Males taking the vitamins differed from those taking the placebo in that they reported themselves as feeling more 'agreeable' after 12 months. After 12 months the mood of females taking the vitamin supplement was significantly improved in that they felt more 'agreeable', more composed and reported better mental health. These changes in mood after a year occurred even though the blood status of 9 vitamins reached a plateau after 3 months: this improvement in mood was associated in particular with improved riboflavin and pyridoxine status. In females baseline thiamin status was associated with poor mood and an improvement in thiamin status after 3 months was associated with improved mood.

Adolescent↗
PubMed1995

[Trauma of the ligaments and tendons. Examination technique and detection in MRI].

For stress radiography, the inversion stress test can be performed during radiographic examination and widening of the lateral joint space can be measured quite accurately. However, there is no general agreement on the meaning of various degrees of talar tilt. Today MRI allows evaluation of the integrity of injured ankle ligaments. The major difficulty in MRI is inconsistency in visualization by inadequate appreciation of the three-dimensional orientation of each ankle ligament. The appropriate combination of foot position and imaging plane is very important to achieve the best visualization of each ligament. Using this technique, 52 patients with sprained ankles underwent MRI. The integrity of rupture of the collateral lateral ligaments was obtained in all 52 ankles. Full-length visualization is essential for evaluation of the ankle ligaments with MRI. In these 52 patients the ankle of tilt on the stress X-ray was compared with the rate of MRI findings showing an injury affecting two ligaments We found that none of the patients in whom the angle of lateral tilt was less than 5 degrees had rupture of two lateral ligaments, while 32% of patients with angles of tilt of 6-14 degrees and 42% of those with angles of tilt over 15 degrees on stress X-ray had two ruptured lateral ligaments. When a stress X-ray with a 6-14 degrees angle of tilt suggests only slight ligamentous injury, MRI could be indicated in specific cases to allow identification of the 32% with rupture of two ligaments. The only practical means of imaging tendons is high-frequency ultrasound and MRI.(ABSTRACT TRUNCATED AT 250 WORDS)

Achilles Tendon↗
PubMed1995

[Sinus tarsi syndrome. MRI diagnosis].

Sinus tarsi syndrome is a well-defined clinical pathological entity. The sinus tarsi is an anatomic space between the inferior aspect of the talus and the superior aspect of the calcaneus, anterior to the posterior subtalar joint. The entire space is filled with fat, five ligaments and vessels. MRI demonstrates characteristic findings with obliteration of normal fat and lack of visualization of the ligaments. This syndrome is relatively frequent and is related to trauma in about 70% in association with the lateral collateral ligament and tibialis posterior tendon injuries. In the remaining 30% the reason is an inflammatory condition.

Calcaneus↗
PubMed1995

[Tarsal tunnel syndrome. MRI diagnosis].

Clinical findings and symptoms of tarsal tunnel are commonly vague and diffuse and electrodiagnostic studies do not provide definitive diagnosis. MR imaging with its excellent soft tissue contrast can demonstrate clearly the anatomy of the tarsal tunnel and its contents. MRI is able to demonstrate a space-occupying lesion and its relationship to the posterior tibial nerve and its branches. This information aids in surgical planning by determining the extent of the decompression required. MR imaging may also be used to follow up non-surgical causes of tarsal tunnel syndrome such as tenosynovitis.

Diagnosis, Differential↗
PubMed1994

Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. Eye Disease Case-Control Study Group.

OBJECTIVE--To evaluate the relationships between dietary intake of carotenoids and vitamins A, C, and E and the risk of neovascular age-related macular degeneration (AMD), the leading cause of irreversible blindness among adults. DESIGN--The multicenter Eye Disease Case-Control Study. SETTING--Five ophthalmology centers in the United States. PATIENTS--A total of 356 case subjects who were diagnosed with the advanced stage of AMD within 1 year prior to their enrollment, aged 55 to 80 years, and residing near a participating clinical center. The 520 control subjects were from the same geographic areas as case subjects, had other ocular diseases, and were frequency-matched to cases according to age and sex. MAIN OUTCOME MEASURES--The relative risk for AMD was estimated according to dietary indicators of antioxidant status, controlling for smoking and other risk factors, by using multiple logistic-regression analyses. RESULTS--A higher dietary intake of carotenoids was associated with a lower risk for AMD. Adjusting for other risk factors for AMD, we found that those in the highest quintile of carotenoid intake had a 43% lower risk for AMD compared with those in the lowest quintile (odds ratio, 0.57; 95% confidence interval, 0.35 to 0.92; P for trend = .02). Among the specific carotenoids, lutein and zeaxanthin, which are primarily obtained from dark green, leafy vegetables, were most strongly associated with a reduced risk for AMD (P for trend = .001). Several food items rich in carotenoids were inversely associated with AMD. In particular, a higher frequency of intake of spinach or collard greens was associated with a substantially lower risk for AMD (P for trend < .001). The intake of preformed vitamin A (retinol) was not appreciably related to AMD. Neither vitamin E nor total vitamin C consumption was associated with a statistically significant reduced risk for AMD, although a possibly lower risk for AMD was suggested among those with higher intake of vitamin C, particularly from foods. CONCLUSION--Increasing the consumption of foods rich in certain carotenoids, in particular dark green, leafy vegetables, may decrease the risk of developing advanced or exudative AMD, the most visually disabling form of macular degeneration among older people. These findings support the need for further studies of this relationship.

Aged↗
PubMed1994

Alpha 2-adrenoceptor blockade, pituitary-adrenal hormones, and agonistic interactions in rats.

The effects of adrenergic activation on aggressiveness and the aggression induced endocrine changes were tested in rats. Alpha 2 adrenoceptor blockers were used for enhancing activation of the adrenergic system, and changes in aggressiveness were tested in resident-intruder contests. Three experiments were conducted. In experiment 1, saline injected rats responded to the presence of an opponent by aggression and the increase in plasma ACTH and corticosterone. Intraperitoneal administration of 1 mg/kg CH-38083 (an alpha 2 adrenoceptor antagonist) produced a several fold increase in clinch fighting and mutual upright scores, and also further enhanced the plasma ACTH and corticosterone response. In experiment 2, the effect of three doses (0.5, 1 and 2 mg/kg) of three different alpha 2 adrenoceptor blockers CH-38083, idazoxan and yohimbine were tested. All the substances increased aggression at 0.5 and 1 mg/kg; at 2 mg/kg the effect of idazoxan and yohimbine disappeared, while with CH-38083 an additional increase was obtained. In yohimbine treated animals the enhancement of aggression was reduced already at 1 mg/kg. In experiment 3, indomethacin, a potent inhibitor of the catecholamine-induced ACTH release completely abolished the effects of the alpha 2 adrenoceptor antagonist CH-38083: the intensity of agonistic interactions, as well as ACTH and corticosterone plasma concentrations, returned to control levels. The possible role of catecholamines and the stress hormones in the activation of aggression is discussed.

Adrenergic alpha-2 Receptor Antagonists↗
PubMed1994

[Radiographic changes of the calcaneus in the framework of chronic polyarthritis].

Plain films of the calcaneus of 768 patients with confirmed rheumatoid arthritis were examined retrospectively with reference to inflammatory rheumatic changes. 42 patients (5.5%) showed an erosion of the posterior upper calcaneal margin related to an Achilles bursitis. In three patients there were additional plantar erosions. The Achilles bursitis was bilateral in 50% of cases, particularly in patients in stages 2 and 3 according to Steinbrocker. In the majority of bilateral cases (62%) the size or shape of the lesions was asymmetrical. Our observations indicate that involvement of the os calcis is not uncommon in rheumatoid arthritis; routine examination of this bone would appear to be indicated even in patients without symptoms. Since the defect is unilateral in half the patients, unilateral occurrence of an erosive lesion cannot be regarded as a criterion for a bacterial-inflammatory bursitis. Contrary to the symmetrical involvement of joints in the hands in rheumatoid arthritis, defects in the calcaneus are often unilateral or asymmetrical.

Achilles Tendon↗
PubMed1993

Comparative postoperative infection rates in midfacial trauma using intermaxillary fixation, wire fixation, and rigid internal fixation implants.

The use of rigid internal fixation implants in the repair of midfacial fractures requires more extensive bone exposure, soft-tissue manipulation, and operative time. We wished to determine the relative contribution of this method of repair to postoperative infection rates. Midfacial trauma cases occurring between the years 1984 and 1991 at the University of Iowa Hospitals and Clinics, Iowa City, were reviewed. Patients were grouped according to method of repair (intermaxillary fixation, open reduction with wire fixation, or open reduction with rigid internal fixation plates). Postoperative infection data (wound infections, sinusitis, etc) were obtained by chart review and telephone interview. Minimum follow-up for inclusion in the study was 3 months, with an average follow-up for all groups of 28.8 months. We found no significant difference in the rate, or the type, of postoperative infections in all three groups. We conclude that rigid internal fixation implants do not contribute increased postoperative infection rates in midfacial trauma.

Adult↗
PubMed1993

Adrenomedullar catecholamine liberation and carbohydrate metabolism during the first 30 min of an aggressive encounter in rats.

The correlation between adrenomedullar catecholamine secretion and metabolic events was investigated in previously isolated fighting male rats. Aggressive encounters were stopped before the apparition of a dominance order. Aggression consisted of short bursts of reciprocal bites, threatening behavior, and short pauses intercalated. After 30 min of fighting, the percent of catecholamine-stained adrenomedullar cells was reduced significantly in fighters. Fighters showed a significant reduction in liver glycogen, while their blood glucose was increased. Muscle-free glucose showed no statistically significant changes compared to controls, while muscle glucose consumption increased. In the muscle of fighting rats, glycogen content was decreased. Our results demonstrated that there is an adrenomedullar activation in early stages of aggression, the changes in carbohydrate metabolism being in correlation with the catecholamine activation.

Adrenal Medulla↗
PubMed1993

Increased cytotoxicity of squamous cell carcinoma of the head and neck by combining cisplatin with VP-16 and ciprofloxacin.

Chemotherapeutic treatment of squamous cell carcinoma (SCC) of the head and neck has been largely ineffective because of tumor cell resistance. This study examined combinations of cisplatin, 4' demethylepipodophyllotoxin ethylidene D-glucoside (VP-16), and ciprofloxacin, a quinolone antibiotic. VP-16 and ciprofloxacin were used in an effort to inhibit DNA repair and increase cytotoxicity. Chemotherapeutic agents often have a direct damaging effect on cellular DNA. Cytotoxicity may be the result of incomplete DNA repair mechanisms; whereas tumor cell resistance to drugs may be due to efficient DNA recovery. A nuclear enzyme especially important to DNA repair and cell growth is topoisomerase II (topo II). Targeted inhibition of topo II by VP-16 and ciprofloxacin may cause increased cisplatin cytotoxicity. SCC cell lines of head and neck origin were treated with a combination of cisplatin, VP-16, and/or ciprofloxacin with cell viability being assessed by the MTT colorimetric assay. Four of five SCC lines examined demonstrated significant augmentation of cisplatin cytotoxicity with the addition of both VP-16 and ciprofloxacin. These in vitro data suggest methods may exist for improving the chemotherapeutic treatment of SCC of the head and neck.

Antineoplastic Combined Chemotherapy Protocols↗