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Biomedical subjects

W Kowalski

Publications and source records attributed to W Kowalski.

At least 19 recordsLinked to original sources
PubMed2001

Biotransformation of phosphogypsum in media containing different forms of nitrogen.

Studies on the biotransformation of phosphogypsum (a waste product formed in the course of the production of phosphorous fertilizers) with the use of sulfate reducing bacteria (SRB) demonstrated that it is a good source of sulfates and biogenic elements for these bacteria, though the addition of organic carbon and nitrogen is necessary. The aim of this study was to investigate the form of nitrogen and C:N ratio in the medium on the growth of SRB community in cultures containing phosphogypsum. Batch community cultures of sulfate reducing bacteria were maintained in medium with phosphogypsum (5.0 g/l), different concentrations of sodium lactate (1.6 - 9.4 g/l) and different forms (NH4CI, CO(NH2)2, KNO3) and concentrations (0 - 250 mg/l) of nitrogen. The growth of SRB was studied in the C:N ratio of from 2:1 to 300:1. It was found that: 1 - the best source of nitrogen for SRB is urea, followed by ammonium, the worst were nitrates; 2 - the bacteria were also able to grow in medium without nitrogen but their activity was then by approximately 15% lower than in optimal growth conditions; 3 - in medium with KNO3 inhibition of sulfate reduction by approx. 50% was observed; 4 - the highest reduction of nitrates (removal of nitrate) in media with phosphogypsum and nitrates was at limiting concentrations of sodium lactate. This is probably caused by the selection under these conditions (low concentration of hydrogen sulfide) of denitrifying bacteria or sulfate reducing bacteria capable of using nitrates as an electron acceptor.

Biodegradation, Environmental↗
PubMed1999

Diurnal changes in plasma prolactin during the last one third of pregnancy in the baboon.

Previous studies in our laboratory revealed that daily plasma prolactin (Prl) levels were higher in the evening than in the morning in the pregnant baboon suggesting a diurnal variation. The goal of this study was to examine in more detail the diurnal alterations in plasma Prl levels. A tethered pregnant baboon model was utilized for these studies. Hourly venous blood samples were taken from 0700 to 2400 hr (n=10) or until 0700 hr the following day (n=5). The studies were performed at various days of pregnancy from day 135 until delivery. Plasma samples were analyzed for Prl by radioimmunoassay. A surge in plasma Prl was detected, starting around 1500 to 1600 hr and lasting for 3 to 5 hr. The surge occurred before the lights went off in the colony (1800 hr). Baseline Prl levels were higher in animals < 15 days before delivery compared to those > 15 days before delivery (P < 0.05). In contrast, no differences were found in the average peak Prl values between these two groups of animals. In summary, in the pregnant baboon during the last one-third of pregnancy plasma Prl surges, beginning around 1500 to 1600 hr and lasting for 3 to 5 hr. Less than 15 days before delivery the mean baseline Prl levels are higher compared to animals greater than 15 days before delivery.

Animals↗
PubMed1998

Hormone replacement therapy usage: a 10 year experience of a solo practitioner.

The objective of this study was to identify factors affecting hormone replacement therapy (HRT) usage among patients of a single physician. All active patients (n = 330) given a HRT prescription over the past 10 years (1985-1995) by the physician were sent a questionnaire on health knowledge, lifestyle patterns, general medical and reproductive histories, responses to HRT usage and decision-making about HRT use. A total of 214 useful questionnaires were returned giving a response rate of 65%. For this cohort, the length of HRT use for those still taking HRT was 60 months; and for those no longer taking HRT, it was 32 months; and 85% of those ever given an HRT prescription were still using HRT at the time of survey. The educational backgrounds, exercise patterns, health knowledge, medical and reproductive histories of this group were representative of those found among suburban postmenopausal women in central Pennsylvania. Among this cohort, the most important reason for them taking HRT was the physicians' recommendation.

Cohort Studies↗
PubMed1998

Multiple sclerosis: the frequency of allelic forms of tumor necrosis factor and lymphotoxin-alpha.

The cytokines LTa and TNF have been implicated as major mediators of tissue injury in multiple sclerosis (MS). In this study we have assessed the frequency of specific polymorphisms for these genes in MS (n = 53) and controls (n = 81) using a highly sensitive, two stage nested polymerase chain reaction (PCR), with the second stage using mutation-specific primers. Genomic DNA was extracted from blood cells and the results confirmed by direct dideoxy chain termination sequencing. The frequency of the -308 G to A mutation in the TNF promoter region in normal controls was 15% and in MS was 24%. For LTa gene the exon 3 polymorphism allele A was detected in 36% of controls and 34% of the MS patients. In MS, the combined genotype TNF G + A and LTa C + C was present 6 times more frequently (12%) than in controls (2%), and patients with this genotype showed the highest EDSS scores. We found the TNF and LTa polymorphisms to occur independently from the HLA class II DR2 allele distribution in MS. Whilst the G - A polymorphism in TNF gene promoter has been studied previously in MS, with conflicting results, this is the first study that has addressed the exon 3 polymorphism in LTa in MS. The results indicate that this polymorphism is not linked with the higher genetic predisposition for MS, but that combined TNF G + A and LTa C + C genotype might contribute to development of the disease.

Alleles↗
PubMed1998

[Platelets oxygen metabolism in women and men in different age groups].

The aim of the study as to assess the influence of the physiological aging process on the platelet cell metabolism in middle-aged people. A group of 17 healthy women (aged 47-59 years), and a group of healthy men (aged 45-60 years) were examined. The control group was composed of healthy women aged 19-25 years, and healthy men aged 19-27 years. The activity of hyperoxide dismutase, catalase, glutathione peroxidase and the concentration of malonyldialdehyde were determined in platelets. In comparison to the control group, a significant decrease in the activity of hyperoxide dismutase and glutathione peroxidase as well as an enhanced concentration of malonyldialdehyde were observed in the group studied. Moreover, a diminished catalase activity was noted in platelets of men, while in women there were no significant changes. The study indicated that disorders in the function of thrombocytes, an excessive generation of oxygen free radicals, and impaired mechanisms of cellular antioxidative defence accelerate atherosclerosis and aging process. Therefore, it is necessary to cover middle-aged people, particularly those occupationally exposed to factors affecting defence mechanisms, with adequate preventive programmes.

Adult↗
PubMed1997

Strategies for ovulation induction and oocyte retrieval in the lowland gorilla.

PURPOSE: Ovulation induction and oocyte retrieval were performed in a lowland gorilla in an attempt to propagate and potentially cryopreserve embryos from an infertile animal and to advance techniques to help preserve this endangered species. RESULTS: Following 34 days of leuprolide acetate suppression, human menopausal gonadotropins were administered for 14-days in a 32-year-old wild-born lowland gorilla. Ten oocytes were retrieved by transrectal ultrasound-guided aspiration. Other approaches to oocyte recovery were not feasible in this case. A serum estradiol concentration of 4700 pg/ml at the time of human chorionic gonadotropin administration did not induce ovarian hyperstimulation. Mature oocytes were recovered from follicles measuring 14 to 24 mm in diameter, with a corresponding average serum estradiol concentration of approximately 300 pg/ml for each mature follicle. Cryopreservation of a gorilla embryo was effected from cryopreserved gorilla spermatozoa. CONCLUSIONS: Parameters for monitoring ovulation induction in the gorilla appear to be similar to those for humans. The results indicate that the use of a gonadotropin releasing hormone agonist and higher doses of gonadotropins than previously used in gorillas appear to improve oocyte recovery.

Animals↗
PubMed1996

The effect of respiratory activity on brain blood flow during exposure to +Gz acceleration.

The effect of respiratory activity on cardiovascular system during the exposure to +Gz acceleration was studied. For simultaneous, beat to beat evaluation of central and global cerebral blood flow, the system based on modified impedance cardiography method was used. The mechanism of modulation of the central and peripheral (cerebral) venous pressures and blood flow by intrathoracic pressure changes, has been shown. The data obtained from these studies suggest that reconsideration of the respiration technique during Anti-GSM seems indispensable.

Acceleration↗
PubMed1996

[Computer analysis of nystagmus].

An algorithm for the computer analysis of nystagmus is described in this paper. This algorhythms was based on digital differentiator, which monitors the eye position. The computed eye velocity is next used as an input to the fast phase detector. Several procedures, including minimum velocity test, slope sense test, SPV and FPV relationship test are invoked to extract the fast phases from the recorded signal. Based on three-years experience (approx. 3000 examinations) using the ENG-PC System in clinical practice we can conclude, that application of the nystagmus detector was useful in most cases. In our opinion, despite from system imperfection which is observed during the analysis of recording disturbed by artifacts, this system has unquestionable advantage over the traditional technique.

Diagnosis, Computer-Assisted↗
PubMed1994

Pharmacokinetics and pharmacodynamics of anordrin (2 alpha, 17 alpha-diethynyl-A-nor-5 alpha-androstane-2 beta, 17 beta-diol diproprionate).

In order to determine the pharmacokinetics of anordrin a dose of 0.2 mg/kg of [3-14 C]anordrin was administered i.v. to 5 cynomolgus monkeys; the same monkeys received the same dose i.m. at a later date. An additional 3 monkeys received 1.0 mg/kg of [3-14C]anordrin i.m. After administration of the compound, the dipropionate esters of anordrin were rapidly hydrolyzed to the dihydroxy parent compound, anordiol. After i.v. administration, anordrin had a mean residence time (MRT) of 5.0 +/- 1.3 (SE) min. [14C]Anordiol formed from [14C]anordrin had an MRT of 139 +/- 27 (SE) min. The metabolic clearance rates (MCR) of anordrin and anordiol were 55 and 34 mL/min.kg, respectively. The apparent volume of distribution at steady state (Vss) for anordrin was 276 mL/kg, 7.5% of body weight of the animals; anordrol had a much larger Vss of 4460 mL/kg. The MRT of anordiol after i.m. administration of 1.0 mg/kg of [14C]anordrin was 26.3 days. An average of 44% of the dose appeared in urine regardless of the route of administration or dose. The MRT values of total radioactivity were the same when calculated from serum or urine after an i.v. dose, but after i.m. administration, values from urine were approximately 60% of that calculated from serum, indicating that products appearing in urine had a shorter MRT than products appearing primarily in feces. A separate group of monkeys was given anordrin i.m. in doses ranging from 0.1 to 0.4 mg/kg on the first day of menses. The regression of length of menstrual cycle on dose was significant (P = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Histologic examination of slow epiphyseal distraction in the femur of rabbits].

Slow, symmetric epiphyseal distraction of the distal femur has been performed in 30 immature rabbits aged 10 weeks (group 1) and 16 weeks (group 2). Histological examination has been carried out after 2, 4, 12 and 24 weeks of distraction in both groups. In all animals hyperplasia and hypertrophy of the distracted epiphysis and regular remodeling of the bony growth zone were found after 4 weeks of follow-up. No premature closure of the physis has been noted compared to the controls. Histological differences observed were attributed to various, age related biological potential and they resulted from physiological involution.

Animals↗
PubMed1993

Effects of subchronic implantation of hydrocortisone phosphate-releasing osmotic pumps on peripheral gonadotropin levels and estradiol feedback to gonadotropin secretion in the cynomolgus monkey.

The purpose of our study was to investigate subchronic effects of moderate hypercortisolemia on serum gonadotropin and estradiol (E2) levels in the primate using a repeated-measures experimental design. Osmotic pumps which released hydrocortisone 21-phosphate (HP) at a dose of 5 mg/day were implanted subcutaneously (s.c.) in each of five cynomolgus monkeys for one menstrual cycle. The pumps were filled with saline for the two control cycles, one of which preceded and one of which followed hormone infusion. Subsequently, osmotic pumps which released HP at a higher dose of 15 mg/day were implanted s.c. in four of the initial five monkeys for the longer period of two menstrual cycles. The pumps were filled with saline for the two additional control cycles, one of which preceded and one of which followed HP infusion at 15 mg/day. The control cycle which followed HP infusion at 5 mg/day and the control cycle which preceded HP infusion at 15 mg/day were separated by at least one menstrual cycle. Administration of HP at the lower dose elevated serum cortisol levels 1.4-fold and decreased serum adrenal androgens to 0.6 of the pretreatment baseline. The higher dose of HP elevated serum cortisol levels 1.7-fold and suppressed serum adrenal androgens to 0.4 of the baseline. In the menstrual cycle following HP infusion serum cortisol levels were depressed to 0.8 and 0.6 of the pretreatment levels after the lower and the higher dose of HP, respectively. Serum levels of adrenal androgens returned to the baseline after the lower dose of HP, but were still suppressed to 0.5 of the baseline after the higher treatment dose. Implantation of pumps which released 5 mg/day of HP did not affect gonadotropin levels in the serum, either in the follicular phase (FP) or the luteal phase (LP) of the menstrual cycle. Serum E2 levels were increased by 77% in the FP during HP infusion at 5 mg/day (p < 0.001), but returned to control values in the LP. Implantation of pumps which released 15 mg/day of HP raised serum luteinizing hormone (LH) levels throughout the two menstrual cycles of treatment, by 111 and 96% in FPs (p < 0.001), and by 84 and 70% in LPs (p < 0.001). Conversely, serum follicle-stimulating hormone (FSH) levels were decreased by 45 and 50% in FPs (p < 0.05), and by 54 and 50% in LPs (p < 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenal Glands↗
PubMed1993

The impact of subchronic hypercortisolemia on progesterone metabolism and the luteinizing hormone-progesterone axis in the cynomolgus monkey.

The purpose of the study was to assess the impact of subchronic hypercortisolemia on progesterone (P) metabolism and production and on peripheral LH levels in a nonhuman primate using a repeated measures experimental design. Osmotic pumps that released hydrocortisone phosphate (HP) at a dose of 15 mg/day were implanted sc in seven cynomolgus monkeys for two menstrual cycles. The pumps were filled with saline for the two control cycles, which either preceded (three animals) or followed (four animals) HP infusion. P metabolism, P production, and episodic secretion of LH were determined 8 +/- 1 days after the serum estradiol peak in the second control cycle and in the second cycle of HP infusion in each monkey, after iv bolus administration of 50 microCi [3H]P, followed by a 6-h blood sampling period. HP infusion elevated serum cortisol levels 1.6-fold. Serum P levels were decreased throughout the luteal phase by 58% (P < 0.01). The MCR of P and the volume of distribution at steady state of P were increased by 200% during HP infusion (both P < 0.005). The production rate of P was increased by HP treatment in five of seven monkeys. HP infusion increased the ratio of 20 alpha-[3H]dihydroprogesterone to [3H]P in serum from 0.5 to 1.0 (P < 0.05) while decreasing the fraction of [3H]P and its metabolites excreted in urine from 20% to 11% (P < 0.05). Serum LH levels, determined over a 5.25-h period in the luteal phase, were elevated by 200% during HP treatment (P < 0.05). Episodic secretion of LH during treatment was characterized by a 660% increase in the pulse amplitude (P < 0.05) and an apparent decrease in the pulse frequency. The results of this study provide evidence that moderate elevation of serum cortisol levels for two menstrual cycles in primates 1) increases the MCR of P, which may be the cause of the observed decrease in serum P levels; and 2) elevates serum LH levels by amplifying its pulse amplitude, which may result in a compensatory rise in the production rate of P.

Animals↗
PubMed1992

Peripheral and not central suppression of ovarian function during osmotic pump infusion of adrenocorticotropin-(1-24) for one menstrual cycle in the cynomolgus monkey and its partial compensation by a transitory elevation of sex hormone-binding globulin levels.

The purpose of our study was to assess the impact of subchronic administration of ACTH-(1-24) on ovarian function in the primate using a repeated measures experimental design. Osmotic pumps that released ACTH-(1-24) at a dose of 67 micrograms/day were implanted sc in four cynomolgus monkeys for one menstrual cycle. The pumps were filled with saline for the two control cycles, one of which preceded and one of which followed peptide infusion. Administration of ACTH-(1-24) elevated cortisol levels in serum 1.6-fold and those in urine 2.2-fold, without affecting adrenal androgen concentrations. In the follicular phase (FP) of the menstrual cycle, infusion of ACTH-(1-24) did not alter serum levels of estradiol, FSH, or LH. However, immunoreactive estrone excretion in urine was decreased by 71% (P less than 0.05), and serum concentrations of sex hormone-binding globulin (SHBG) were increased by 100% (P less than 0.01). In the luteal phase (LP) of the menstrual cycle, infusion of ACTH-(1-24) suppressed levels of serum estradiol by 54% (P less than 0.001), urinary immunoreactive estrone by 72% (P less than 0.05), serum progesterone by 53% (P less than 0.001), and urinary immunoreactive pregnanediol by 71% (P less than 0.01). Serum FSH concentrations were increased during treatment by 100% (P less than 0.001) in LP, but LH concentrations were not altered. Also, serum levels of SHBG returned to control values in the LP. The lengths of menstrual cycles and the lengths of FP or LP were not affected during or after treatment. These data provide evidence that subchronic infusion of ACTH-(1-24) in primates: 1) suppresses estradiol production by the ovarian follicle as well as estradiol and progesterone production by the corpus luteum, 2) compromises ovarian function without concomitant suppression of serum gonadotropin levels, and 3) induces a transitory elevation of SHBG levels in the circulation, which may compensate for reduced estrogen output.

Animals↗
PubMed1992

Effects of subchronic infusion of dehydroepiandrosterone sulfate on serum gonadotropin levels and ovarian function in the cynomolgus monkey.

OBJECTIVE: To assess the impact of elevated adrenal androgen levels on ovarian function in a nonhuman primate using a repeated measures experimental design. DESIGN: Osmotic pumps that released dehydroepiandrosterone sulfate (DHEAS) were implanted subcutaneously in five cynomolgus monkeys (Macaca fascicularis) for one menstrual cycle. The pumps were filled with saline for the two control cycles, one preceding and the other following DHEAS infusion. RESULTS: Administration of DHEAS elevated its levels in serum fourfold and in urine sevenfold, which returned to pretreatment values in the next cycle. Serum concentrations of estradiol (E2) were reduced by 55% during DHEAS administration in both follicular and luteal phases and were still decreased in the following cycle by 69% in follicular phase and 48% in luteal phase (P less than 0.01). Luteal serum progesterone (P) levels were diminished by 52% during treatment and were accompanied by 56% reduction in immunoreactive pregnanediol excretion in urine (P less than 0.05). Serum luteinizing hormone (LH) levels were decreased during DHEAS infusion by 51% in follicular phase and 58% in luteal phase (P less than 0.01) but returned to baseline in the next cycle. Conversely, serum follicle-stimulating hormone (FSH) concentrations were increased during treatment by 70% in follicular phase and 101% in luteal phase and remained increased by 58% in follicular phase of the next cycle (P less than 0.05). Estrone excretion in urine was higher during DHEAS infusion (1.5-fold increase) but was below pretreatment values in the following cycle by 57% in follicular phase and 51% in luteal phase (P less than 0.001). Administration of DHEAS did not change significantly serum levels of sex hormone-binding globulin. The length of menstrual cycles was not affected by increased levels of adrenal androgens either. However, in the cycles that followed DHEAS infusion, follicular phase was prolonged by an average of 9 days, and luteal phase was shortened by an average of 5 days (P less than 0.01). CONCLUSIONS: These data document that subchronically elevated adrenal androgen levels in primates: (1) suppress E2 and P levels, which may affect fertility; (2) differentially affect gonadotropin secretion, decreasing LH and increasing FSH serum concentrations; and (3) result in disturbances of ovarian function that persist for at least one menstrual cycle after normalization of androgen levels.

Animals↗
PubMed1991

Sick absence in dockers.

The reasons for sick absence in dockers performing heavy loading jobs (stevedores) in the port of Gdynia, in 1986-1991, were identified and subjected to statistical analysis. The study group consisted of 603 people--73% of the whole population of dockers in the port. The prevailing reason were the diseases of the musculoskeletal system--on the average 5.6 days of sick leave per 1 docker per year--28.7% of the total sick absence in the occupational group studied. On the second place were traumas, mainly of the extremities and of the spine--4.7 days (24.9%). The proportion of the circulatory system diseases was a mere 1.9-0.4 days. The high sick absence caused by the first group of diseases calls for preventive interventions during pre-entry and periodic medical examinations of dockers.

Absenteeism↗
PubMed1989

[Current views on the treatment of endometriosis].

The authors present modern views on the therapy of endometriosis, paying much attention to pathophysiological aspects. They present both conventional methods, as hormonal therapy or surgery, and non-conventional methods as laser laparoscopy, microsurgery and fertilization in vitro. The authors stress the lack of casual treatment of endometriosis, which does not result in full effectiveness of the therapy and sometimes there is recurrence of the disease.

Danazol↗
PubMed1989

[Immunologic aspects of endometriosis].

The paper presents modern views on immunological conditioning of endometriosis. It seems that lowered cellular response, intensified humoral response and increased activation of peritoneal macrophages play an important role in the pathogenesis of endometriosis. Immunological research may lead to pharmacological causal treatment of endometriosis considering abnormal function of the immunological system. The paper also discusses the importance of the first biochemical marker of endometriosis--antigen CA-125--in the diagnostics and monitoring the disease.

Antigens, Tumor-Associated, Carbohydrate↗