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Biomedical subjects

G Ronquist

Publications and source records attributed to G Ronquist.

At least 19 recordsLinked to original sources
PubMed1997

Postpolio muscular dysfunction: relationships between muscle energy metabolism, subjective symptoms, magnetic resonance imaging, electromyography, and muscle strength.

Eleven patients with previous polio were studied. The concentration of energy-related metabolites and energy charge was measured from the vastus lateralis muscle, as was isometric muscle strength of knee extension. Cross-sectional area of the quadriceps femoris muscle was calculated from magnetic resonance imaging. Reinnervation was studied using macroelectromyography. Muscle weakness, pain, and newly acquired muscle weakness in the legs was estimated by the patients. The findings in the legs in which the patients experienced new loss of muscle function were compared with the stable legs. There were no significant differences between these groups in any of the objectively measured variables. Only hip pain correlated with new loss of muscle function. Creatine phosphate was decreased in 5 patients. The symptoms and subjective muscle strength did not correlate with any of the objective measurements. There were no significant relationships between energy-related metabolites and postpolio symptoms.

Adult↗
PubMed1997

No further improvement of ischaemic myocardial metabolism by combining preconditioning with beta-blockade: an in vivo experimental study in the pig heart using a microdialysis technique.

Adenine nucleotides, lactate and pyruvate were monitored by microdialysis in pig hearts, comprising four experimental groups. Two preconditioned groups, one beta-blocked by metoprolol (0.3 mg kg-1 body wt; n = 6) and the other (n = 7) without beta-blockade. Two groups were not preconditioned, one beta-blocked (n = 6) and one without beta-blockade (n = 7). Probes were inserted into ischaemic and non-ischaemic myocardium. Preconditioning consisted of four consecutive 10 min periods of ischaemia each separated by 20 min of reperfusion. All animals were subjected to 40 min of index ischaemia followed by 25 min of reperfusion. Myocardial cAMP content was determined in biopsies after the final reperfusion and was found low in the beta-blocked groups. Lactate levels during index ischaemia exceeded the basal level 4-6 fold in dialysate. Adenosine concentration reached 12 mumol L-1 during the first preconditioning period while an attenuation was typical for the following three preconditioning periods. The sum of the concentrations of adenosine inosine and hypoxanthine was significantly lower during index ischaemia in the preconditioned groups displaying a peak value of 115 mumol L-1. The corresponding value for unpreconditioned hearts was 230 mumol L-1. The part of adenosine was 5% and less than 1%, respectively. Pyruvate concentration decreased during each brief ischaemic period of preconditioning rising to a higher level of reperfusion. The decrease in pyruvate was smaller in the controls during index ischaemia. The effects of beta-blockade and preconditioning on ischaemic metabolism were comparable and the results of the two treatments were not additive in this respect.

Adrenergic beta-Antagonists↗
PubMed1997

Response of myocardial cellular energy metabolism to variation of buffer composition during open-chest experimental cardiopulmonary resuscitation in the pig.

The aim of the present study was to investigate possible relationships in piglets between myocardial energy-related metabolites and intracellular electrolytes during open-chest cardiopulmonary resuscitation (OCCPR) supplemented by the administration of alkaline buffers with varying sodium content. Our hypothesis was that an increasing myocardial intracellular sodium content would decrease the intracellular energy stores. In addition to haemodynamics, acid-base and blood gas variables were analysed, and myocardial biopsies were collected before and during OCCPR as well as after the return of spontaneous circulation. After a period of 4 min of untreated ventricular fibrillation (VF). 25 piglets were randomly allocated to one of four groups: OCCPR with normal saline (n = 5); OCCPR with sodium bicarbonate (SB) (n = 7); OCCPR with Tris buffer mixture (TBM) (n = 7); and a totally untreated control group (n = 6). The results showed that 4 min of untreated VF almost eradicated creatine phosphate (CrP) and that the ATP/ADP ratio decreased to 1.5-2.0. During OCCPR with normal saline, the myocardial content of CrP increased, whereas lactate, ATP and ADP levelled off and AMP decreased, causing an increased ATP/ADP ratio. The adenosine and inosine contents increased, whereas inosine monophosphate was unchanged at a low level, the adenosine and inosine contents being inversely correlated with the total content of adenine nucleotides. In both buffered groups, the increase in most energy-related metabolites (CrP, ATP, ADP, AMP and the ATP/ADP quotient) was less and in lactate more pronounced than in the group not being buffered, with no difference between the groups receiving SB or TBM. Although the intracellular potassium content was unaltered, the sodium, chloride and calcium concentration increased, more so in the group receiving SB. The intracellular content of sodium was correlated with that of calcium. Thus, buffering increased the myocardial AMP degradation during OCCPR by increasing the flux via the 5'-nucleotidase reaction, and SB increased the intracellular contents of sodium and calcium to a greater extent than did TBM.

Adenosine Diphosphate↗
PubMed1997

Human uterine smooth muscle exhibits a very low phosphocreatine/ATP ratio as assessed by in vitro and in vivo measurements.

The purpose of the study was to investigate by in vitro and in vivo methods the phosphocreatine (PCr)/ ATP ratio as an expression of the energy metabolic state of human myometrium in comparison with striated skeletal muscle. The contents of PCr and adenylates in biopsies of uterine smooth muscle and m. rectus abdominis from seven term pregnant women were determined in vitro and compared with results obtained in vivo by phosphorus magnetic resonance spectroscopy (31P-MRS) in the uterus and m. gastrocnemius of eight non-pregnant women. The PCr/ATP ratio in the striated skeletal muscle was about three times higher than that of the myometrium. The results of the in vitro biopsy part of the study and the in vivo 31P-MRS part conformed with each other. In the biopsies both PCr and ATP concentrations were significantly lower in the myometrium than in the rectus muscle, but the difference for PCr was more pronounced, accounting for the significantly lower PCr/ATP ratio in the uterine smooth muscle. The energy metabolic pattern of uterine smooth muscle differs from that of striated skeletal muscle regarding the contents of high-energy phosphocompounds and the PCr/ATP ratio. This in vivo finding is the first report on human smooth muscle using 31P-MRS.

Adenosine Diphosphate↗
PubMed1997

Effects of adrenergic and muscarinic agonist stimulation on IP3 and cyclic nucleotide levels in the pressure overloaded rat heart.

In this study, the dynamic interrelationships between myocardial functional state and changes in the second messenger content in pressure-overloaded hypertrophied hearts were investigated. Forty-three rat hearts were used after partial clamping of the abdominal aorta. The isolated hearts were perfused with Krebs-Henseleit buffer and allocated to perfusion for 20 s or 40 min as controls (n = 12); or with noradrenaline (10(-6) mol l-1, n = 11); carbachol (3 x 10(-7) mol l-1, n = 9); or noradrenaline plus carbachol (10(-6) mol l-1 + 3 x 10(-7) mol l-1, respectively, n = 11). maxdP/dt increased more than 2-fold already after 20 s on noradrenaline stimulation, followed by a significant increase in cAMP. After 40 min, maxdP/dt was lower than the maximal value, although higher than controls. cAMP was also decreased, but still significantly higher than controls. Perfusion with noradrenaline plus carbachol produced the same changes in maxdP/dt as those seen after noradrenaline stimulation alone, but failed to increase cAMP content after both 20 s and 40 min. The inositol trisphosphate (IP3) content was increased 40 min of control perfusion (p < 0.05). Noradrenaline and carbachol, separately, produced an increase in IP3 content already after 20 s (p < 0.05). The combination of noradrenaline plus carbachol also produced an increase of IP3 (p < 0.05; compared to controls), but to a lesser extent when compared either to noradrenaline or carbachol (p < 0.05). After 40 min of perfusion, IP3 was in the same range regardless of added agonist(s) and still slightly above control level (p < 0.05). The early increase in maxdP/dt induced by noradrenaline or the combination of noradrenaline plus carbachol was not paralleled by a decrease in ATP content. This was also the case upon addition of carbachol alone. However, after 40 min of agonistic perfusion, ATP levels were substantially decreased. In conclusion, myocardial IP3 content in pressure-overloaded hypertrophied hearts was not different from that of sham-operated hearts. After agonistic stimulation, an early increase in IP3 formation was seen. Attenuation of the IP3 response by combined stimulation with noradrenaline and carbachol was initially present in pressure-overloaded hypertrophied hearts. After 40 min no attenuation was found for either IP3 or for cAMP content, suggestive of induction of a desensitization.

Adrenergic Agonists↗
PubMed1997

Anti-human prostasome MAB 78 binds to antigen distinct from PSA and PAP.

PURPOSE: The characteristics of an antigen corresponding to a monoclonal antibody (mAb 78) against human prostasomes were compared with prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP). The correspondence of Ag 78 to two other prostate-derived antigens, prostasin and peptide pGlu-Phe-Pro-NH2, were also considered. MATERIALS AND METHODS: The immunoreactivity of mAb 78 and the cross-reactivity of mAb 78 with PSA and PAP were studied with immunohistochemical and enhanced chemiluminescence (ECL) Western blotting methods. RESULTS: The mAb 78 did not bind to PSA blots, and anti-PSA antibody did not label prostasome blots. Neither did PSA and PAP impede the binding of mAb 78 onto prostasome blots nor to paraffin sections of prostate epithelium. Afer Western blots, mAb 78 bound diffusely to a band with a molecular weight of 35 kDa, but did not bind to PSA 933 kDa) or PAP (monomer 50 kDa, intact molecule 100 kDa) bands. From purified 35 kDa bands, three fractions were sequenced, which showed no similarities to PSA and PAP. CONCLUSIONS: The Ag 78 is different from PSA and PAP, and probably also from prostasin and peptide pGlu-Phe-Pro-NH2. The mAb 78 can be used as a new marker for human prostasomes.

Acid Phosphatase↗
PubMed1996

Prostasomes are neuroendocrine-like vesicles in human semen.

BACKGROUND: Prostasomes are prostate-derived organelles that exist extracellularly in human seminal plasma. METHODS: In this study, we have investigated and characterized human prostasomes with regard to their contents of synaptophysin, members of the chromogranin family, and some neuropeptides. RESULTS: By radioimmunoassay measurement and electron microscopy we show the presence of the neuroendocrine markers chromogranin B, neuropeptide Y, and vasoactive intestinal polypeptide in about equimolar amount in human prostasomes and chromogranin A in about 2% of that amount. To our knowledge, such a high ratio of chromogranin B to chromogranin A has never before been observed. The membrane-bound protein synaptophysin, a well-established immunocytochemical marker for neuroendocrine cells and neurones, was also detected. Hence, we show that synaptophysin could be used as a marker for intact prostasomes. CONCLUSIONS: The presence of synaptophysin has recently been shown in the serotonincontaining vesicles in platelets. A protein with a similar structure denoted granulophysin has been found in granulocytes and prostasomes. It is suggested that synaptophysin and granulophysin molecules are members of a family of proteins, maybe expressed in all cells that have regulated release of granule content. Our presented data indicate a neurotransmittor function of the prostasomes. The target cells are however not known but could be either the spermatozoa, the epithelial mucous cells of the uterus or tubas or perhaps the ovum.

Antigens, CD↗
PubMed1996

Glyburide enhancement of lactate production in ischemic heart is modified by preconditioning: an in vivo experimental study in pigs by microdialysis technique.

The concentrations of lactate, pyruvate, and adenosine, together with some of their derivatives, were determined in microdialysates from 12 pig hearts, 6 of which were subjected to preconditioning and 40 min of ischemia (index ischemia) and 6 of which were subjected to only 40 min of index ischemia. Two microdialysis probes were inserted in ischemic myocardium. Glyburide (10 mu M) in a modified isotonic Krebs-Ringer phosphate buffer was administered through one of the probes and plain isotonic phosphate buffer was administered through the other. Accordingly, the experimental setup permitted us to study the metabolic effects of glyburide on ischemic myocardium constituting two groups that were either preconditioned or unpreconditioned. The preconditioning effect was validated with area at risk and infarction area measurements in 12 other pigs. We noted no functional differences between the groups. In the unpreconditioned group glyburide infusion resulted in enhanced 60% lactate production during index ischemia. However, preconditioning attenuated the enhancing effect of glyburide on lactate production. The interplay between the effects of glyburide and preconditioning on ischemic myocardium is suggested to be dependent on the different modes of action on the K(+)(ATP) channel.

Adenosine Triphosphate↗
PubMed1996

Neutral and cationic amino acids in striated rectus muscle are generally in excess of those in smooth uterine muscle of term pregnant women.

The concentrations of 24 amino acids and four other related compounds were determined in extracts of biopsy specimens from myometrium and musculus rectus abdominis of 10 healthy term pregnant women during elective cesarean sections. The total free amino acid pool did not differ significantly between the two muscle types. There was a myometrial abundance of the two anionic amino acids glutamate and aspartate and the two aromatic amino acids tyrosine and phenylalanine, but most neutral and cationic amino acids in striated skeletal muscle tissue were found in excess of those in uterine muscle tissue.

Adult↗
PubMed1996

Allopurinol treatment results in elevated prostate-specific antigen levels in prostatic fluid and serum of patients with non-bacterial prostatitis.

Non-bacterial prostatitis is a common problem in young men. It is a disease which is often recurrent and each episode lasts for several months. Different causative mechanisms of the disease have been discussed including identified and non-identified microorganisms, stone formation and psychological factors. It was shown in an earlier study that urinary reflux (as shown by a high creatinine concentration in prostatic fluid) took place to a varying extent in the prostatic ducts and this reflux was related to prostatic pain and urate concentration in expressed prostatic secretion (EPS). Allopurinol treatment lowered the urate concentration in EPS and relieved the subjective discomfort. This study reports serum (S) levels of prostate-specific antigen (PSA) in patients with non-bacterial prostatitis and the way in which S-PSA was affected by allopurinol treatment. It is also shown that the S-PSA level is age dependent. A correlation existed between the S-PSA concentration and EPS content of white blood cells. Patients with high EPS urate concentrations corresponded to low S-PSA levels and allopurinol treatment resulted in elevated S-PSA levels. PSA in EPS was also increased by allopurinol treatment. Hence, an increased release of PSA from the prostate gland was noted upon allopurinol treatment. The mechanism of the allopurinol-induced release is obscure. It might be explained by an induction of PSA synthesis via an allopurinol effect on the genome but an increased leakage of the prostatic cells elicited by allopurinol could no be ruled out.

Adult↗
PubMed1996

Activation of AMP deaminase in human erythrocytes by calcium ions.

We examined 5'-AMP aminohydrolase (AMP deaminase, EC 3.5.4.6. AMPD) together with metabolite changes in intact red blood cells from normal human adults under different incubation conditions. Moderate changes occurred in erythrocyte adenylates upon incubation for 1 h at 37 degrees C in the absence of glucose and the concentration of IMP was negligible. Calcium in the incubation medium, at concentrations up to 1.50 mmol l-1 did not influence the nucleotide pattern. Inclusion of the ionophore A 23187 in the incubation medium resulted in a sharp decrease of ATP content at 60 min and increases in AMP and ADP concentrations. A maximally low level of ATP was observed at 60 min of incubation in the presence of both the ionophore and 0.25 mmol l-1 of external calcium. With increasing concentrations of calcium up to 1.50 mmol l-1 in the presence of the ionophore, a significant rise occurred in both IMP and ATP concentrations, whether glucose was present or not, and significant correlations existed between the concentrations of calcium and IMP. The presence of the ionophore together with glucose but without extra calcium in the incubation medium produced the highest concentrations of lactate, indicative of an enhanced glycolytic flux under these conditions. The stimulatory effect of intracellular calcium ions on AMPD activity is discussed.

AMP Deaminase↗
PubMed1996

Occurrence of adenylate kinase in cerebrospinal fluid after isoflurane anaesthesia and orthognathic surgery.

UNLABELLED: The study objective was, firstly, to investigate whether anaesthesia with induced arterial hypotension would cause leakage of a biochemical marker of neuronal injury, adenylate kinase (AK), into the cerebrospinal fluid (CSF). ( DEFINITION: arterial hypotension = mean arterial pressure (MAP) 50-65 mmHg during > or = 10 min). Secondly, a subgroup of patients was examined with a limited battery of psychometric tests. Patients, scheduled for orthognathic surgery, were allocated to either hypotension (n = 20) or normotension (n = 20). Seventeen patients were subjected to psychometry. Arterial blood pressure was recorded continuously and controlled by adjustments of the administered concentration of the inhalational anaesthetic isoflurane. Fentanyl, an opioid, was given equally in both groups. A lumbar puncture was performed approximately 20 h post-operatively for a CSF sample, later analysed for AK activity. Neuropsychological tests were performed the day before surgery and the fourteenth day postoperatively. The CSF-AK value was pathologically increased ( > 0.040 U/L) in 24 patients (65%), of whom 9 were normotensive. There was no significant difference between the CSF-AK values in the hypotensive and normotensive groups, mean values were 0.082 (s.d. 0.051) and 0.066 (s.d. 0.059) U/L, respectively. The overall correlation between the 10 min MAP levels and the CSF-AK values was close to zero. In the pilot neuropsychological investigation some abnormalities were observed, indicating clinically significant adverse effects in four hypotensive patients, of whom two displayed pathologically increased CSF-AK values. At the group level, the correlation between the changes in psychometry and the measured CSF-AK values was poor. Increases in CSF-AK activities may be a non-specific occurrence in the perioperative interval, possibly indicating an adverse effect on the brain. Arterial hypotension could not be proven to explain the CSF-AK outcome.

Adenylate Kinase↗
PubMed1996

Immunolocalization of prostasomes in the human prostate.

Prostasomes are prostate-derived organelles, which can be isolated from seminal plasma. We have produced a panel of monoclonal antibodies against purified human prostasomes by intrasplenic immunization. Among the prostasome-positive mAbs obtained, one antibody (mAb 78) was selected for further characterization. SDS-PAGE and Western blots demonstrated that mAb 78 recognized a hand of about 35 kDa from purified prostasomes, seminal plasma and extracts of prostatic gland tissues. Immunostaining with mAb 78 resulted in positive reactions in the apical parts of the secretory cells of the prostate epithelium and in the secretions of the gland lumen. The nuclei were not stained. The mAb 78 has the potentials of a prostasome marker.

Animals↗
PubMed1996

Faecal microflora and urease activity during the first six months of infancy.

Gastrointestinal degradation of urea might, according to a new hypothesis, have consequences for the regulation of acid-base balance as well as control of breathing during infancy. Thirteen infants were investigated from their first few days of life to the age of 6 months by collecting faecal samples at the age of 3 days, 2, 3, and 6 months, respectively. The faecal microflora was determined after aerobic and anaerobic cultivation and the faecal urease activity was assessed after 36 h aerobic and anaerobic preincubation. The infants were mostly breast fed and had a faecal microflora containing anaerobic bacteria such as Bifidobacteria, Bacterioides and Lactobacilli but also aerobics such as Escherichia coli, Enterococci and sometimes Klebsiella. The faecal pH increased from approximately 5.30 to 5.90, the pH after anaerobic preincubation being on an average 0.2 pH units lower than after aerobic preincubation. Simultaneously the nitric oxide production of the faecal specimens increased approximately 10-fold and the urease activity decreased by a factor of 3 to 5. We also found an inhibitory action of nitrate, nitrite (in mumolar concentration) and nitric oxide (in parts per million concentration) on the faecal urease activity. Hence, the present results warrant further research in order to determine more precisely the action of different concentrations of various nitrous oxides on individual bacterial species, and furthermore, to assay the faecal urease activity in victims of sudden infant death syndrome as well as in infants dead due to other causes.

Bacteria, Aerobic↗
PubMed1996

Evidence for a mechanistic association between nonbacterial prostatitis and levels of urate and creatinine in expressed prostatic secretion.

PURPOSE: Chronic prostatitis is a common disease of the late teenage years, which affects patients for many years. In the majority of cases etiology is unknown but in some cases prostatitis is clearly caused by microorganisms that result from overuse of antibiotic drugs. We attempt to gain further knowledge about the etiology of the disease. MATERIALS AND METHODS: We studied 56 patients with nonbacterial prostatitis in regard to whether urine reflux into the prostatic ducts was responsible for increased concentrations of creatinine, urate and white blood cells in expressed prostatic secretion. The patients were interviewed using a standard questionnaire. RESULTS: A relationship was demonstrated between pain estimated in accordance with a scoring scale, and expressed prostatic secretion contents of white blood cells, urate and creatinine. CONCLUSIONS: These results provide further support of the role of reflux into the prostatic ducts as an underlying mechanism initiating a chemical inflammatory reaction. Urate appears to be the chemical agent eliciting this inflammatory response.

Creatinine↗
PubMed1996

Ameliorative effect of allopurinol on nonbacterial prostatitis: a parallel double-blind controlled study.

PURPOSE: Nonbacterial prostatitis is a common problem in young men. It is a disease that is often recurrent and each episode lasts for several months. Different causative mechanisms of the disease have been discussed, including identified and unidentified microorganisms, stone formation and psychological factors. We have demonstrated in a previous study that urinary reflux (as shown by a high creatinine concentration in prostatic fluid) occurs to a varying extent into the prostatic ducts, and this reflux has been related to prostatic pain and urate concentration in expressed prostatic secretion. MATERIALS AND METHODS: We performed a paralled double-blind controlled study of the objective and subjective effects of allopurinol on patients with nonbacterial prostatitis. Twenty patients received placebo, 18 received 300 mg. allopurinol daily and 16 received 600 mg allopurinol daily for 240 days. All patients began medication at the same time regardless of whether the disease was in an active state. No side effects were noted in the treatment groups. RESULTS: Significant effects were noted on the concentrations of serum urate, urine urate, expressed prostatic secretion urate, expressed prostatic secretion xanthine and subjective discomfort. CONCLUSIONS: Allopurinol has a significant, positive effect on nonbacterial prostatitis. It is safe and worthy of trial for all at least a 3-month period at each episode to relieve the symptoms of nonbacterial prostatitis.

Allopurinol↗