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Biomedical subjects

W Kozak

Publications and source records attributed to W Kozak.

At least 73 records · Page 4Linked to original sources
PubMed1988

Effect of some anesthetics on memory and exploration.

A light ether anesthesia in laboratory mice resulted in the complete drop of their memory retrieval to zero for more than three days after the administration. On the contrary, mice that underwent the exploration test after the light ether anesthesia performed as expected, confirming that impairment of memory does not necessarily reflect on exploratory performance. The effect of some anesthetic drugs was then studied on memory retrieval and exploratory behavior. Within this general framework, the anesthetics here studied all worsen memory retrieval, however without inducing clear and long-lasting amnesic effect comparable to that exerted by ether anesthesia. Contrarily, the classically amnesic drug scopolamine, orally administered, enhances memory retrieval and improves exploration.

Anesthetics↗
PubMed1988

Difference in learning and retention by Albino-Swiss mice. Part 5. Effect of some antidepressants.

According to the methods described earlier (1), the effect of some antidepressants on memory retention in "good" and "poor" learning mice was studied. The present study indicates that several antidepressants have different activity on memory retrieval of the two subtypes of animals, which is directly responsible for the results here reported. In general terms, the data obtained show that, in addition to the classical antidepressant activity, some derivatives may exert a behavioral disinhibition.

Animals↗
PubMed1987

The incidence of candidiasis amongst the asymptomatic female students of the University of Jos, Nigeria.

A survey was carried out on the incidence of candidiasis amongst the asymptomatic female students of University of Jos. One hundred and three students were selected at guided random. Their first stream urine samples were collected with the aid of sterile McCarthney bottles. The deposits of the centrifuged urine samples were plated out on sabouraud's dextrose agar (SDA) fortified with antibiotics (penicillin G and streptomycin). A total number of 42 positive Candida cases were obtained. This represented 40.78% of the total samples (103) examined. The Candida species isolated included C. albicans, C. glabrata, C. guilliermondi, C. parapsilosis, C. pseudotropicalis, C. stellatoidea, C. tropicalis and C. viswanathii. C. albicans and C. tropicalis were more predominant than the other species. C. albicans had 38.10% frequency of occurrence while C. tropicalis had 21.43% occurrence. The least percentage occurrence was recorded for C. viswanathii which had 2.38%. There were significant relationships between the incidence of candidiasis and the predisposing factors like drug administration (antibiotics and contraceptive pills), cases of pregnancy and previous cases of urinogenital tract infection. Neither the marital status nor the age groups of the test female students had significant effects on the incidence of this disease. The pH values of the infected urine samples had a significant effect on the incidence of the disease.

Adult↗
PubMed1987

Exploratory behavior and the dual activity of some psychoactive drugs. Part 1.

Animal behavior in a free environment involves the orienting reflex, a major component of which is exploratory behavior. Exploration is an essential, life-preserving component of animal higher nervous functions and the experiments presented here show that exploratory behavior may differ according to the experimental subjects' emotional baseline. Exploratory performance may accordingly be affected differently by psychoactive drugs.

Alprazolam↗
PubMed1987

Activity of phosphatidylserine on memory retrieval and on exploration in mice.

Recent human and animal studies have reported about neurochemical and behavioral changes occurring during aging. Bovine brain phosphatidylserine (BC-PS) administered in vivo was reported to produce changes in the metabolic status of the brain and in behavioral performances. Within the Albino-Swiss strain of mice two subtypes have been shown to exist with different learning and memory retention abilities. These animals also have different reactions to various psychoactive drugs. The experiments presented here deal with the hypothesis that BC-PS may show different effects according to the starting emotional status of the animals. The technique of intracerebral injection was employed to ensure active concentrations of BC-PS in the brain. The results reported here show that BC-PS clearly improves performances in the subtype of mice with poor exploratory activity.

Administration, Oral↗
PubMed1987

Exploratory behavior and the dual activity of some psychoactive drugs: Part II.

Exploration is an essential, life-preserving component of animal higher nervous functions. The experiments presented here show that exploratory behavior may differ according to the experimental subject's emotional baseline, and that exploratory performance is accordingly affected differently by some nutrients and central stimulants.

Animals↗
PubMed1987

Difference in learning and retention by Albino-Swiss mice. Part IV. Effect of some nutrients.

According to the preceding papers, the possible difference in activity of some nutrients on memory retrieval of "good" and "poor" learning mice was studied. Among the substances used, only phenylalanine significantly improved memory recall of poor learning mice. On the contrary, tryptophan, tyrosine, phosphatidylserine and choline did not influence memory retention of previously learned avoidance of both poor and good learning mice.

Amino Acids↗
PubMed1986

Effect of 6-OHDA injected into the locus coeruleus on apomorphine-induced aggression.

Bilateral microinjections of 6-hydroxydopamine (6-OHDA) into the nuclei loci coerulei (LC) of male Wistar rats resulted in significant depletion of mesencephalic and striatal norepinephrine, accompanied by a small reduction in dopamine content only in the striatum. Apomorphine (2.5 mg/kg IP) induced marked aggression consisting of prolonged posturing, vocalization and attacks only in 6-OHDA lesioned animals. Biochemical analysis revealed that 6-OHDA antagonized the ability of apomorphine to raise the serotonin concentration in the striatum. It is concluded that the LC neurons play an inhibitory role in apomorphine-induced aggressiveness and the involvement of serotonergic neurons is suggested.

Aggression↗
PubMed1986

[Simplified hamster ovum-sperm penetration test (HSPT) in routine sterility testing].

In 67 patients, in most of whom the spermiogram did not, a priori, furnish definitive proof of fertility, the hamster egg human sperm penetration test was performed as part of a screening programme for infertility therapy conducted from February 1984 to February 1985. Evaluation of the test was facilitated by identification of the decondensed spermatozoon head in the penetrated hamster egg with a simple fluorescein staining instead of the usual aceto-lacmoid staining. The penetration rate (= percentage proportion of the hamster ova liberated from the zona pellucida which are penetrated within 3 hours following incubation with 1 million motile spermatozoa) was evaluated statistically in comparison to the fertility criteria of the spermiogram (motility, density, pathoforms), in order to verify the existence of possible fertility disturbances due to inability to penetrate despite the motility of the spermatozoa. In 42 patients the diagnosis of infertility was confirmed by a penetration rate of less than 10%. In 17 patients fertility was conformed according to HSPT (penetration rate of over 20%), while in 7 patients fertility was in the lower normal range. In the light of the authors' findings fertility confirmed by the HSPT is a precondition of referral for extracorporeal insemination. In the light of the authors' findings intrauterine insemination appears advisable for women whose fertility is in the lower normal range according to HSPT.

Adult↗
PubMed1985

Arylsulphatase A and acid phosphatase activities in plasma and leucocytes during LPS fever in the ox (Bos taurus).

Intravenous injection of E. coli LPS (0.5 micrograms/kg) produced the biphasic elevation of rectal temperature (TR) in conscious oxen. The fever was accompanied by a significant increase of the arylsulphatase A (AsA) activities in plasma and in mononuclear leucocytes. In polymorphonuclear cells a substantial decrease of the AsA activity after 1 hr fever was observed. After 3.5 hr of fever the polymorphonuclear activity of AsA restored to normal found before LPS administration. In contrast with AsA, the pyrogenic dose of LPS caused negligible changes of the acid phosphatase (AcP) activities in the sampled materials. Daily-repeated injections of pyrogen into the same oxen attenuated magnitudes of fever as well as AsA responses in plasma and granulocytes. Heat-induced hyperthermia provoked only minute changes of the AsA and AcP.

Acid Phosphatase↗
PubMed1984

Anxiolytic activity on locus coeruleus-mediated suppression of muricidal aggression.

The evidence suggests that stimulation of brain noradrenergic neurons plays an inhibitory role in rat mouse-killing (muricidal) aggression. Anxiolytic benzodiazepines inhibit locus coeruleus activity and previous data showed that chlordiazepoxide was capable of antagonizing the locus coeruleus-mediated suppression of muricidal aggression. The present experiments showed that this effect is common to new anxiolytic triazolobenzodiazepines and to other non-benzodiazepine derivatives with anxiolytic activity. In this framework, 10 mg/kg of buspirone, of 1-pyrimidine-piperazine and of MJ-13805 proved to be as active as 2.5 mg/kg of alprazolam and as 5 mg/kg of chlordiazepoxide in inhibiting the locus coeruleus-mediated suppression of muricidal aggression.

Aggression↗
PubMed1984

Activity of desipramine, fluoxetine and nomifensine on spontaneous and p-CPA-induced muricidal aggression.

Antidepressant drugs reportedly counteract mouse-killing activity by rats. There is evidence that antidepressant derivatives exert their anti-muricidal activity through both noradrenergic and serotonergic neurons. The experiments were performed in two types of muricidal aggression with three antidepressants characterized by different neurochemical activity. No major differences in the antimuricidal efficacy of the drug-employed were found, even though spontaneous muricidal animals resulted on the whole less sensitive to antidepressants than p-CPA-induced muricidal rats. In these last animals nomifensine proved to be more potent than desipramine and fluoxetine.

Aggression↗
PubMed1984

The modified method for isolation and culture of highly homogeneous Leydig cell population from rat testes.

A modified method for isolation and culture of a pure population of rat Leydig cells is described. For obtaining crude interstitial cell suspension, decapsulated testes were dispersed in 0.02% collagenase solution in Ca2+, Mg2+--free Hanks medium for 1 hour. Then, approx. 5 X 10(7) cells were centrifuged in 10-90% discontinuous, isoosmotic Percoll gradient at 3000 g for 20 min. The cells from eight fractions obtained were collected and cultured in Eagle's MEM for 4 days. Using morphological methods, 1.059-1.070 g/ml density fraction contained 97% and 1.070-1.080 g/ml fraction contained 90% viable Leydig cells. The cells secreted testosterone to the culture medium and responded to LH stimulation with over four-fold increase in hormone secretion.

Animals↗