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Biomedical subjects

R Kaminski

Publications and source records attributed to R Kaminski.

At least 19 recordsLinked to original sources
PubMed2001

On the interactions between antimuscarinic atropine and NMDA receptor antagonists in anticholinesterase-treated mice.

Both organophosphate (OP) and carbamate pesticides may produce seizures and death commonly attributed to the inhibition of acetylcholinesterase (AChE) and subsequent excess of acetylcholine (ACh). The anticonvulsant and neuroprotective properties of N-methyl-D-aspartate (NMDA) receptor antagonists in animals encouraged us to investigate their effects on the toxic and convulsant properties of OP and carbamate pesticides. Adult Swiss mice were systemically injected with the OP pesticide, chlorfenvinphos (CVP), or the carbamate pesticide, methomyl (MET). Both CVP and MET induced dose-dependent seizure activity and death in mice. Pretreatment with the muscarinic antagonist, atropine (ATR), at a dose of 1.8 mg/kg did not prevent seizures but decreased the lethal effects of CVP and MET. Pretreatment with the NMDA antagonists, dizocilpine (MK-801) at a dose of 1 mg/kg or 3-((R,S)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) at a dose of 10 mg/kg, influenced neither MET-induced seizures nor CVP- or MET-induced death. However, both MK-801 and CPP blocked CVP-induced seizures. Concurrent administration of ATR and the NMDA antagonists prevented seizures produced by CVP, but not those produced by MET. Nevertheless, both MK801 and CPP coadministered with ATR markedly enhanced its antilethal effects in CVP- and MET-intoxicated mice. The antidotes had no influence upon brain AChE activities in mice treated with saline or CVP or MET. It seems that combined treatment with ATR and NMDA receptor antagonists might be of clinical relevance.

Acetylcholinesterase↗
PubMed2000

[Remission of nocturnal pathological respiratory patterns after orthotopic heart transplantation. A case report and overview of current status of therapy].

BACKGROUND: Cheyne-Stokes respiration is characterized by recurrent phases of central apneas during sleep alternating with a crescendo-decrescendo hyperventilation. This abnormal respiratory pattern is often observed in patients with severe congestive heart failure and associated with fragmentation of sleep, excessive daytime sleepiness, and a relatively high mortality. Increased peripheral and central chemosensitivity, prolonged circulation time, and reduced blood gas buffering capacity are the major factors contributing to the pathology. However, the exact pathophysiologic mechanisms are not clear yet. Respiratory stimulants, oxygen and continuous or bilevel positive airway pressure (CPAP or BiPAP) might reduce the severity of Cheyne-Stokes respiration but have little effect on daytime sleepiness and cardiac function. There is only limited data supporting the assumption that intensive heart failure therapy has an effect on Cheyne-Stokes respiration. CASE REPORT: A 55-year-old male patient with dilative cardiomyopathy (NYHA IV) suffered excessive daytime sleepiness (Epworth Sleepiness Scale: 24 points). The patient was a heavy snorer with a normal body mass index. Treatment was initiated including ACE-inhibitors, beta-receptor blockers, diuretics and digoxin. The patient underwent sleep analysis with a Somno-Check system which demonstrated Cheyne-Stokes breathing (Respiratory Disturbance Index RDI: 40/h, lowest desaturation 76%) and body position dependent snoring. Oxygen therapy (21/min) had no effect on daytime sleepiness. Due to the cardiac condition, the patient was accepted for heart transplantation. Three weeks after transplantation sleep analysis was repeated and demonstrated a lack of evidence for periodic breathing (RDI 1/h, no desaturations below 90%), while snoring remained unchanged. Daytime sleepiness improved significantly (Epworth Sleepiness Scale: 6 points). Three weeks after normalizing left ventricular function a complete recovery from severe Cheyne-Stokes respiration was observed. CONCLUSION: Adequate therapy of the underlying cause of Cheyne-Stokes breathing such as end-stage congestive heart failure might sufficiently abolish any breathing abnormalities.

Cheyne-Stokes Respiration↗
PubMed2000

The radical cation of syn-tricyclooctadiene and its rearrangement products

The syn dimer of cyclobutadiene (tricyclo[4.2.0.0(2.5)]octa-3,7-diene, TOD) is subjected to ionization under different conditions and the resulting species are probed by optical and ESR spectroscopy. By means of quantum chemical modelling of the potential energy surfaces and the optical spectra, it is possible to assign the different products that arise spontaneously after ionization or after subsequent warming or illumination of the samples. Based on these findings, we propose a mechanistic scheme which involves a partitioning of the incipient radical cation of TOD between two electronic states. These two states engage in (near) activation-less decay to the more stable valence isomers, cyclooctatetraene (COT*+) and a bis-cyclobutenylium radical cation BCB*+. The latter product undergoes further rearrangement, first to tetracyclo[4.2.0.0(2,4).0(3,5]oct-7-ene (TCO*+) and eventually to bicyclo[4.2.0]octa-2,4,7-triene (BOT*+) which can also be generated photochemically from BCB*+ or TCO*+. The surprising departure of syn-TOD*+ from the least-motion reaction path leading to BOT*+ can be traced to strong vibronic interactions (second-order Jahn-Teller effects) which prevail in both possible ground states of syn-TOD*+. Such effects seem to be more important in determining the intramolecular reactivity of radical cations than orbital or state symmetry rules.

Journal Article↗
PubMed2000

Preparation of hexacoordinated tris(bidentate) phosphorus compounds with 1,3,2-dioxaphosphorinane rings. NMR and X-ray crystallographic studies of their conformation

A series of new unstable tris(bidentate) hexacoordinated phosphorus compounds 1 with 1,3,2-dioxaphosphorinane rings was prepared and studied by NMR and X-ray crystallography. The X-ray crystal structures showed that the 1,3,2-dioxaphosphorinane ring adopts different conformations depending on the number and size of substituents at the carbon atom C14. Substituents are deployed around the phosphorus atom in a slightly deformed octahedral structure. Deviations in bond lengths around the phosphorus atom depend on the character of the bonds and the distribution of the negative charge. (1)H and (13)C NMR measurements showed that in solution the flexibility of 1,3,2-dioxaphosphorinane ring depends on the size of substituents at the carbon C14.

Journal Article↗
PubMed2000

Sleep stage dependant changes of the high-frequency part of the somatosensory evoked potentials at the thalamus and cortex.

OBJECTIVES: It is known that the high-frequency oscillations (above 400 Hz) of the somatosensory evoked potentials (SEPs) diminish during sleep while the N20 persists (Neurology 38 (1988) 64; Electroenceph clin Neurophysiol 70 (1988) 126; Electroenceph clin Neurophysiol 100 (1996) 189). We investigated possible differential effects of sleep on the 600 Hz SEPs at the thalamus and cortex. METHODS: SEPs from 10 subjects were recorded using 64 channels following electric stimulation at the wrist during awake state and sleep stages II, IV and REM. Dipole source analysis was applied to separate brain-stem, thalamic and cortical activity in the low-frequency (20-450 Hz) and the high-frequency (450-750 Hz) part of the signal. RESULTS: The low-frequency SEPs showed a non-significant increase of the latency of the N20 and a bifid change of the waveform in 3 subjects. The high-frequency SEPs showed a significant decrease of their amplitude at the level of the thalamus and cortex but not at the brain-stem. This decrease in amplitude at the thalamus and cortex were significantly correlated. There was no effect on the latency of the signal. In addition, at the cortex, differential effects on early and late parts of the 600 Hz oscillations were found by time-frequency analysis using a wavelet transformation. CONCLUSIONS: Sleep dependent decrease of the high-frequency SEPs were first observed at the thalamus pointing to the known function of the reticular thalamic nucleus regulating arousal. The results presented here provide further evidence for a thalamic origin of the 600 Hz oscillations. In addition, on the basis of the differential effects on early (up to the N20 peak) and late (between 20 and 25 ms) parts of the signal, at least one intracortical generator of these oscillations is proposed. In general, the high-frequency SEPs (600 Hz oscillations) are supposed to reflect activity of a somatosensory arousal system.

Adult↗
PubMed2000

Organochlorine pesticides concentration in the drinking water from regions of extensive agriculture in Poland.

Considerable amounts of organochlorine pesticides (DDT, lindane, heptachlor and methoxychlor) were detected in drinking water samples during a two-year study in Warka-Grojec rural region of Poland. The average incidence of drinking water sources with detectable levels of pesticides ranged from 20 to 30%. According to Polish regulations concerning water quality, individual concentrations did not reach the maximum admissible level. However, the levels of pesticides in most cases exceeded the maximum admissible concentrations recommended by the European Union

Agriculture↗
PubMed1999

Effect of amlodipine upon the protective activity of antiepileptic drugs against maximal electroshock-induced seizures in mice.

Amlodipine, a calcium channel antagonist of the dihydropyridine class, up to 10 mg kg(-1)(i.p.) did not significantly affect the threshold for electroconvulsions. However, this calcium channel antagonist (10 mg kg(-1)) enhanced the anticonvulsive activity of carbamazepine, valproate and phenobarbital against maximal electroshock-induced seizures in mice. Furthermore, amlodipine (5 mg kg(-1)) intensified the protection offered by carbamazepine. This effect was associated with the increased free plasma level of carbamazepine in the presence of amlodipine. Amlodipine did not influence the free or total plasma level of phenobarbital and valproate, so a pharmacokinetic interaction is not probable for valproate and phenobarbital. The anticonvulsive action and free plasma level of diphenylhydantoin was not modified by amlodipine. The combined treatment of the calcium channel antagonist and antiepileptics caused motor impairment (evaluated in the chimney test). Long-term memory (assessed in the passive avoidance test) in case of combinations of amlodipine with carbamazepine or diphenylhydantoin was not affected. The combination of amlodipine with valproate or phenobarbital significantly influenced the retention in this test. A possible usefulness of amlodipine as add-on therapy in epileptic patients may be limited by its considerable adverse effect revealed by behavioural tests. The pharmacokinetic interaction between carbamazepine and amlodipine might have some clinical importance for patients treated with these drugs.

Amlodipine↗
PubMed1998

Effect of non-steroidal anti-inflammatory drugs on the anticonvulsive activity of valproate and diphenylhydantoin against maximal electroshock-induced seizures in mice.

Prostaglandins and their inhibitors may affect convulsive phenomena. Thus, the aim of this study was to examine possible interactions between non-steroidal anti-inflammatory drugs and two conventional antiepileptic drugs in terms of their anticonvulsive activity and side-effects. Also, the plasma levels of antiepileptics were measured in order to delineate possible pharmacokinetic interactions. The following non-steroidal anti-inflammatory drugs (NSAIDs) were studied: acetylsalicylic acid, ibuprofen, indomethacin, metamizole, paracetamol and piroxicam. None of these drugs affected the threshold for electroconvulsions. However, all NSAIDs studied enhanced the protective activity of valproate magnesium against maximal electroshock-induced seizures. Only ibuprofen and piroxicam enhanced the anticonvulsive activity of diphenylhydantoin. Ibuprofen decreased the ED50 value of valproate (for the induction of motor impairment) in the rotorod test, whilst piroxicam reduced the ED50 value of valproate in rotorod and chimney tests. Diphenylhydantoin combined with either ibuprofen or piroxicam did not cause any motor impairment in these tests. The total plasma level of valproate and free plasma level of diphenylhydantoin remained unchanged in the presence of all studied NSAIDs. These data demonstrate that NSAIDs could enhance the protective activity of antiepileptics. However, in case of valproate it may be associated with the severe side effects.

Animals↗
PubMed1995

The use of famotidine in the treatment of Parkinson's disease: a pilot study.

Seven patients with idiopathic Parkinson's disease were enrolled in a ten week study to evaluate the efficacy of famotidine, an histamine H2-antagonist, in the treatment of bradyphrenia. Patients received famotidine 80 mg/day for a period of six weeks and were evaluated with neuropsychological tests. Overall, patients demonstrated improvement in variables measured. Some patients also reported an improvement in their motor symptoms.

Aged↗
PubMed1992

Training-overtraining: influence of a defined increase in training volume vs training intensity on performance, catecholamines and some metabolic parameters in experienced middle- and long-distance runners.

The influence of an increase in training volume (ITV; February 1989) vs intensity (ITI; February 1990) on performance, catecholamines, energy metabolism and serum lipids was examined in two studies on eight, and nine experienced middle- or long-distance runners; seven participated in both studies. During ITV, mean training volume was doubled from 85.9 km.week-1 (pretrial phase) to 174.6 km within 3 weeks. Some 96%-98% of the training was performed at 67 (SD 8)% of maximal performance. During ITI, speed-endurance, high-speed and interval runs increased within 3 weeks from 9 km.week-1 (pretrial phase) to 22.7 km.week-1 and the total training distance from 61.6 to 84.7 km.week-1. The ITV resulted in stagnation of running velocity at 4 mmol lactate concentration and a decrease in total running distance in the increment test. Heart rate, energy metabolic parameters, nocturnal urinary catecholamine excretion, low density, very low density lipoprotein-cholesterol and triglyceride concentrations decreased significantly; the exercise-related catecholamine plasma concentrations increased at an identical exercise intensity. The ITI produced an improvement in running velocity at 4 mmol lactate concentration and in total running distance in the increment test; heart rate, energy metabolic parameters, nocturnal catecholamine excretion, and serum lipids remained nearly constant, and the exercise-related plasma catecholamine concentrations decreased at an identical exercise intensity. The ITV-related changes in metabolism and catecholamines may have indicated an exhaustion syndrome in the majority of the athletes examined but this hypothesis has to be proven by future experimental studies.

Adult↗
PubMed1991

Training-overtraining. A prospective, experimental study with experienced middle- and long-distance runners.

Overtraining may be one frequent cause of stagnation or decrease in performance capacity of athletes. Israel (19) differentiates between addisonoid (parasympathetic) and basedowoid (sympathetic) overtraining, characterized by inhibition or excitation. We tried to induce an overtraining syndrome in 8 experienced middle- and long-distance runners, based on an increase in training volume from an average 85.9 km (week 1) to 115.1 km (week 2) and 143.1 km (week 3) to 174.6 km per week (week 4). The influence of this training on cardiovascular, metabolic and hormonal parameters was examined with special respect to plasma and urinary catecholamines. Laboratory testing including graded treadmill running was performed on the days 0, 14 and 28. Training was held six days each week, with nearly 30 km per day in the fourth week. A stagnation in endurance performance capacity (running velocity at the aerobic-anaerobic transition range) and a decrease in maximum working capacity were observed in 6 and a stagnation in 2 of the 8 sportsmen, indicated by a decrease in total running distance from 4719 + 912 m to 4361 + 788 m during incremental treadmill ergometry. The sportsmen could neither improve nor could they even approximately reach their personal records during the subsequent competitive season. Subjective complaints, classified on a four-point scale, increased from 1.2 (week 1) to 3.2 in week 4. Glucose, lactate, ammonia, glycerol, free fatty acids, albumin, LDL, VLDL cholesterol, hemoglobin level (transient), leukocytes, and heart rate (before and during exercise) decreased significantly. Urea, creatinine, uric acid, GOT, GPT, gamma-GT, serum electrolytes (except phosphate and calcium) remained constant at the measuring times, CPK was elevated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Measurement of plasma homovanillic acid concentrations in schizophrenic patients.

1. Several lines of evidence suggest that abnormalities of central dopaminergic transmission may be involved in the expression of some schizophrenic symptoms. However, elucidation of the role of dopamine (DA) in schizophrenia has eluded investigative efforts partially because no accurate and easily repeatable measure of brain DA activity exists. 2. The development of a technique to measure homovanillic acid in plasma has offered the possibility of performing serial measurements of this major DA metabolite. 3. Assuming that plasma homovanillic acid (PHVA) concentrations is an index of brain DA activity, measurement of PHVA can play a role in elucidating the DA abnormality in schizophrenia. 4. Results to date suggest that plasma homovanillic acid concentrations are lower in chronic schizophrenic patients compared to normal controls, and that PHVA values correlate with schizophrenic symptom severity. 5. In addition, PHVA levels were shown to initially rise and subsequently decline during chronic neuroleptic administration in treatment responsive but not in treatment refractory schizophrenic patients.

Biomarkers↗
PubMed1981

Occupational information on death certificates: a survey of state practices.

A national survey was conducted in 1979 to determine the extent to which state and local vital registration offices coded and stored occupational information reported on death certificates. This survey found that 11 states routinely code occupation, seven routinely code industry, and six have coded occupation and/or industry on a limited basis. State and federal cooperation is needed to facilitate increased use of mortality data for environmental and occupational health research.

Death Certificates↗
PubMed1980

Mortality analysis of plumbers and pipefitters.

The United Association of Journeymen and Apprentices of the Plumbing and Pipefitting Industry was concerned about the numerous occupational hazards to which its members were exposed and therefore wanted to determine whether unusual mortality patterns could be identified among its membership. The National Institute for Occupational Safety and Health undertook a mortality analysis of the United Association's members and found significant excesses of cancer of the esophagus and of the respiratory and lymphatic systems among those in the plumbing trade. Although plumbers are potentially exposed to several known and suspected carcinogens, additional study is needed to further document the excesses and to determine whether these excesses can be related to specific occupational exposures.

Humans↗