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Biomedical subjects

M Valtonen

Publications and source records attributed to M Valtonen.

At least 19 recordsLinked to original sources
PubMed2001

Contents of vitamins, mineral elements, and some phenolic compounds in cultivated mushrooms.

The aim of the study was to determine the contents of mineral elements (Ca, K, Mg, Na, P, Cu, Fe, Mn, Cd, Pb, and Se), vitamins (B(1), B(2), B(12), C, D, folates, and niacin), and certain phenolic compounds (flavonoids, lignans, and phenolic acids) in the cultivated mushrooms Agaricus bisporus/white, Agaricus bisporus/brown, Lentinus edodes, and Pleurotus ostreatus. Selenium, toxic heavy metals (Cd, Pb), and other mineral elements were analyzed by ETAAS, ICP-MS, and ICP methods, respectively; vitamins were detected by microbiological methods (folates, niacin, and vitamin B(12)) or HPLC methods (other vitamins), and phenolic compounds were analyzed by HPLC (flavonoids) or GC--MS methods (lignans and phenolic acids). Cultivated mushrooms were found to be good sources of vitamin B(2), niacin, and folates, with contents varying in the ranges 1.8--5.1, 31--65, and 0.30--0.64 mg/100 g dry weight (dw), respectively. Compared with vegetables, mushrooms proved to be a good source of many mineral elements, e.g., the contents of K, P, Zn, and Cu varied in the ranges 26.7--47.3 g/kg, 8.7--13.9 g/kg, 47--92 mg/kg, and 5.2--35 mg/kg dw, respectively. A. bisporus/brown contained large amounts of Se (3.2 mg/kg dw) and the levels of Cd were quite high in L. edodes (1.2 mg/kg dw). No flavonoids or lignans were found in the mushrooms analyzed. In addition, the phenolic acid contents were very low.

Agaricales↗
PubMed2001

Adenosine in myocardial protection given through three windows of opportunity. An experimental study with pigs.

OBJECTIVE: Adenosine (ADO) has been shown to have beneficial effects against tissue injury after myocardial ischemia. However, the timing and dose of ADO administration have not been defined. This study was designed to determine the cardioprotective effect of exogenous ADO in an experimental open heart surgery model in pigs. DESIGN: The animals were openly divided into two groups both undergoing 30 min of total cardiac arrest. In the control group animals received cold crystalloid cardioplegic solution. In the ADO group ADO was added to cardioplegic solution and in addition ADO was infused to the superior vena cava for 2 h starting 30 min before cardiac arrest. The pumping function of the heart was measured with echocardiography and myocardial blood flow was measured with microspheres and positron emission tomography (PET). Cardiomyocyte apoptosis was detected and tumor necrosis factor (TNF) levels were measured. RESULTS: Better post-ischemic pumping function was found in the ADO group (relative decrease 43.7% vs 55.4%, p = 0.20 between the groups). The cardiac output decreased significantly from the baseline values (p < 0.05 in both groups). There was a temporary decrease in myocardial blood flow post-ischemically, followed by a compensatory increase during the later reperfusion period. The cardiomyocyte apoptosis was induced significantly in both groups. CONCLUSIONS: In this experiment two important details were noticed. Firstly, cardiomyocyte apoptosis is involved in ischemia-reperfusion injury associated with open heart surgery. Secondly, PET is a comparable method with the microsphere technique when coronary flow is studied. No significant effects of ADO against ischemia-reperfusion injury could be shown. However, there were some signsof positive outcome, even though statistical significance could not be reached.

Adenosine↗
PubMed2001

Elimination of the piperacillin/tazobactam combination during continuous venovenous haemofiltration and haemodiafiltration in patients with acute renal failure.

The elimination of the piperacillin/tazobactam combination was studied in six patients with acute renal failure undergoing either continuous venovenous haemofiltration (CVVH) or continuous venovenous haemodiafiltration (CVVHDF) at 1 L/h and 2 L/h for 12 h. Piperacillin 4 g/tazobactam 0.5 g was given iv on three successive treatment periods and their concentrations in plasma, ultrafiltrate/dialysate and urine were determined for 12 h after each dose. The elimination half-life of piperacillin during CVVH (7.7 +/- 2.3 h; mean +/- s.d.) was significantly longer than during CVVHDF 1 L/h (6.7 +/- 1.9 h) or 2 L/h (6.1 +/- 2.0 h) (P< 0.05). Corresponding values for tazobactam were 13.9 +/- 3.9, 11.6 +/- 3.3 and 9.4 +/- 2.4 h, respectively (P< 0.05). Total piperacillin clearance during CVVH (3.89 +/- 1.23 L/h) was significantly lower than during CVVHDF 1 L/h (5.06 +/- 1.68 L/h) or 2 L/h (5.48 +/- 2.11 L/h) (P< 0.05). The corresponding tazobactam clearance values were 2.42 +/- 0.75, 3.13 +/- 0.66 and 3.75 +/- 1.43 L/h, respectively. The mean 12 h elimination of piperacillin and tazobactam in ultrafiltrate/dialysate was 29% and 37% during CVVH, 42% and 57% during CVVHDF (1 L/h), and 46% and 69% during CVVHDF (2 L/h). We recommend 8 hourly dosing of patients with renal failure on CVVH or CVVHDF with dialysis flow rates of 1 or 2 L/h treated with piperacillin 4 g/tazobactam 0.5 g.

Acute Kidney Injury↗
PubMed2000

Natural transfer of viable microbes in space.

The possibility and probability of natural transfer of viable microbes from Mars to Earth and Earth to Mars traveling in meteoroids during the first 0.5 Ga and the following 4 Ga are investigated, including: --radiation protection against the galactic cosmic ray nuclei and the solar rays, dose rates as a function of the meteorite's radial column mass (radius x density), combined with dose rates generated by natural radioactivity within the meteorite; and survival curves for some bacterial species using NASA's HZETRN transport code --other factors affecting microbe survival: vacuum; central meteorite temperatures at launch, orbiting, and arrival; pressure and acceleration at launch; spontaneous DNA decay; metal ion migration --mean sizes and numbers of unshocked meteorites ejected and percentage falling on Earth, using current semiempirical results --viable flight times for the microbe species Bacillus subtilis and Deinococcus radiodurans R1 --the approximate fraction of microbes (with properties like the two species studied) viably arriving on Earth out of those ejected from Mars during the period 4 Ga BP to the present time, and during the 700 Ma from 4.5 to 3.8 Ga. Similarly, from Earth to Mars. The conclusion is that if microbes existed or exist on Mars, viable transfer to Earth is not only possible but also highly probable, due to microbes' impressive resistance to the dangers of space transfer and to the dense traffic of billions of martian meteorites which have fallen on Earth since the dawn of our planetary system. Earth-to-Mars transfer is also possible but at a much lower frequency.

Bacillus subtilis↗
PubMed2000

Disseminated hydatid disease causing paraplegia and destruction of the hip.

A patient who had had been treated by surgery for spinal echinococcosis in a Mediterranean country emigrated to northern Europe. After surgery, the echinococcosis disseminated and he developed chronic lytic and sinus-draining hydatid disease of the left hip and neuromuscular weakness of the left lower extremity. Seventeen years after the spinal surgery, he was referred to our hip service for a possible total hip replacement (THR) after receiving adequate chemotherapy against echinococcosis for nearly 3 years. Because of the poor results reported by others, we decided against THR; two of the four previous patients described in the current literature who had THR died due to complications.

Adult↗
PubMed2000

Elimination of meropenem during continuous veno-venous haemofiltration and haemodiafiltration in patients with acute renal failure.

Meropenem elimination was studied in six patients with acute renal failure on continuous venovenous haemofiltration (CVVH) or continuous veno-venous haemodiafiltration (CVVHDF) 1 L/h and 2 L/h for 12 h. Meropenem 1 g was given iv over three dialysis periods, and plasma, ultrafiltrate/dialysate and urine concentrations of meropenem were determined. The half-life of meropenem was significantly longer (P < 0.05) during CVVH (7.5 +/- 2.0 h; mean +/- S.D.) than during CVVHDF 1 L/h (5.6 +/- 1.4 h) or 2 L/h (4.8 +/- 1.2 h). Meropenem clearance was 3.27 +/- 2.30 L/h, 4.72 +/- 2.69 L/h and 5.71 +/- 3.58 L/h in CVVH, CVVHDF 1 L/h and CVVHDF 2 L/h, respectively (P < 0.05 between CVVH and CVVHDF). Patients with renal failure on CVVHDF 1 or 2 L/h should be treated with meropenem 1 g bid; 500 mg tid may be enough for patients on CVVH.

Acute Kidney Injury↗
PubMed2000

Intramucosal pH and endotoxin and cytokine release in severe acute pancreatitis.

It has been postulated that in severely ill patients splanchnic hypoperfusion may cause endotoxin release from the gut, and this leakage of endotoxin into the circulation can trigger the cascade of inflammatory cytokines. We tested this hypothesis in 9 patients with acute severe pancreatitis by monitoring gastric intramucosal pH (pHi) as measure of splanchnic hypoperfusion at 12-h intervals trying to correlate it to endotoxin and cytokine release. Only 3 of 59 samples, obtained from 3 patients contained circulating endotoxin. Thirteen of 15 plasma samples drawn at pHi <7.20 did not contain endotoxin. The pHi was significantly lower in patients who subsequently developed 3 or more organ failures (P = 0.0017, analysis of variance). Although endotoxemia was only occasionally found, most patients had measurable interleukin 1beta (IL-1beta), interleukin 6 (IL-6), interleukin 8 (IL-8), and interleukin 10 (IL-10) in their plasma. Concentrations of IL-6, IL-8, and IL-10 on admission correlated to degree of organ dysfunction as measured by the multiple organ system failure score (P = 0.035, r = 0.74; P = 0.010, r = 0.91; P = 0.021, r = 0.82, respectively). In conclusion, patients with acute, severe pancreatitis often have splanchnic hypoperfusion and produce a wide array of cytokines despite a rare occurrence of endotoxemia.

APACHE↗
PubMed1999

Infrarenal endoluminal bifurcated stent graft infected with Listeria monocytogenes.

Prosthetic graft infection as a result of Listeria monocytogenes is an extremely rare event that recently occurred in a 77-year-old man who underwent endoluminal stent grafting for infrarenal abdominal aortic aneurysm. The infected aortic endoluminal prosthesis was removed by means of en bloc resection of the aneurysm and contained endograft with in situ aortoiliac reconstruction. At the 10-month follow-up examination, the patient was well and had no signs of infection.

Aged↗
PubMed1999

Interleukin 1 receptor antagonist and E-selectin concentrations: a comparison in patients with severe acute pancreatitis and severe sepsis.

PURPOSE: This prospective clinical study was designed to compare interleukin 1 receptor antagonist (IL-1ra) and E-selectin concentrations in patients with severe acute pancreatitis to those with severe sepsis. MATERIALS AND METHODS: Nine consecutive patients with severe acute pancreatitis and 11 consecutive patients with severe sepsis admitted to a medical/surgical intensive care unit were included in the study. Plasma concentrations of IL-1ra and E-selectin were serially measured daily for 7 days or throughout their stay in the intensive care unit if shorter. RESULTS: The concentrations of IL-1ra were significantly higher on admission in patients with severe sepsis compared with the patients with severe pancreatitis (median levels 10,500 and 2,600 pg/mL, respectively, P = .007). When the data from the first 3 days were analyzed using analysis of variance (ANOVA), the levels of IL-1ra and E-selectin were similar in both groups. The concentrations of IL-1ra and E-selectin correlated to the development of multiorgan dysfunction as assessed by sequential organ failure assessment (SOFA) score (P = .032 and .043, respectively). CONCLUSION: This study shows that IL-1ra and E-selectin are released in acute severe pancreatitis, and the levels seem to be comparable to those in patients with severe sepsis. Concentrations of IL-1ra and E-selectin correlate to the development of multiorgan failure as indicated by high SOFA scores during the first week of disease.

APACHE↗
PubMed1999

Central nervous system involvement in gyrate atrophy of the choroid and retina with hyperornithinaemia.

In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), a genetically determined deficiency of ornithine delta-aminotransferase activity leads to high ornithine concentrations in body fluids. GA is characterized by centripetally progressing retinal and choroidal destruction and selective atrophy with tubular aggregates in type II skeletal muscle fibres. These findings have been suggested to be mediated by hyperornithinaemia-induced deficiency of high-energy creatine phosphate. As abnormal brain magnetic resonance images and electroencephalograms are found in another disorder of creatine metabolism, guanidinoacetate methyltransferase deficiency, we investigated the central nervous system involvement in GA, which seems to be associated with a milder degree of phosphocreatine deficiency. We compared 23 untreated GA patients with age-matched healthy controls, and with 9 patients who had received creatine or creatine precursor supplementation daily for several years. The mean age of the patients (32 +/- 18 years) was similar to that of the controls (36 +/- 22 years). The MRI or EEG findings of the patients on creatine supplementation did not differ from those of the untreated group. Brain MRI revealed degenerative lesions in the white matter in 50% of the GA patients, and 70% of the patients had premature atrophic changes, with a striking increase in the number of Virchow's spaces. Of the patients whose EEG was recorded, 58% had abnormal slow background activity, focal lesions or high-amplitude beta rhythm (> 50 microV). The EEG findings were not associated with the MRI changes or with the age or the sex of the patients. Early degenerative and atrophic brain changes and abnormal EEG are thus features of GA, in addition to the well-characterized eye and muscle manifestations.

Adolescent↗
PubMed1999

Muscle creatine phosphate in gyrate atrophy of the choroid and retina with hyperornithinaemia--clues to pathogenesis.

BACKGROUND: In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), inherited deficiency of ornithine-o-aminotransferase leads to progressive fundus destruction and atrophy of type II skeletal muscle fibres. Because high ornithine concentrations inhibit creatine biosynthesis, the ensuing deficiency of high-energy creatine phosphate may mediate the pathogenesis. MATERIALS AND METHODS: Relative concentrations of inorganic phosphate (Pi), creatine phosphate (PCr) and ATP in resting calf muscle were recorded in 23 GA patients and 33 control subjects using 31P-magnetic resonance spectroscopy (MRS). Eight patients with autosomal recessive retinitis pigmentosa with matched control subjects constituted an additional reference group. RESULTS: The PCr/Pi and PCr/ATP ratios (means +/- SD) were lower for the GA patients than for healthy control subjects [4.66 +/- 0.37 vs. 9.75 +/- 2.17 (P < 0.0001) and 2.85 +/- 0.37 vs. 3.70 +/- 0.50 (P < 0.05) respectively]. In retinitis pigmentosa the respective values were 9.12 +/- 2.57 and 4.25 +/- 0.45. Age and stage of the disease had no effect. CONCLUSION: Muscle 31P-MRS spectra were markedly abnormal in all GA patients.

Adenosine Triphosphate↗
PubMed1999

Life-threatening Mycoplasma hominis mediastinitis.

Mycoplasma hominis infections are easily missed because conventional methods for bacterial detection may fail. Here, 8 cases of septic mediastinitis due to M. hominis are reported and reviewed in the context of previously reported cases of mediastinitis, sternum wound infection, pleuritis, or pericarditis caused by M. hominis. All 8 patients had a predisposing initial condition related to poor cardiorespiratory function, aspiration, or complications related to coronary artery surgery or other thoracic surgeries. Mediastinitis was associated with purulent pleural effusion and acute septic symptoms requiring inotropic medication and ventilatory support. Later, the patients had a tendency for indolent chronic courses with pleuritis, pericarditis, or open sternal wounds that lasted for several months. M. hominis infections may also present as mild sternum wound infection or as chronic local pericarditis or pleuritis without septic mediastinitis. Treatment includes surgical drainage and debridement. Antibiotics effective against M. hominis should be considered when treating mediastinitis of unknown etiology.

Adult↗
PubMed1998

Diurnal rhythm of melatonin in bovine milk: pharmacokinetics of exogenous melatonin in lactating cows and goats.

We investigated whether the melatonin levels in bovine milk exhibit a similar daily rhythm as serum levels. In 4 Ayrshire cows at the beginning of the lactation period in May the nocturnal rise in milk melatonin was moderate (from 7 +/- 2 pg/ml at noon to 15 +/- 1 pg/ml at night; mean +/- SEM) and did not correlate well with the melatonin level in serum (from 7 +/- 2 pg/ml to 27 +/- 7 pg/ml, respectively). On the other hand, 6 cows in a later phase of lactation, studied in February, showed a clear long-lasting nocturnal melatonin increase both in serum (from 9 +/- 1 pg/ml at noon to 26 +/- 3 pg/ml at night) and in milk (from 12 +/- 5 pg/ml to 26 +/- 7 pg/ml, respectively). Melatonin kinetics during lactation was studied in more detail in 4 Ayrshire cows and 4 dairy goats by giving an intravenous bolus injection of melatonin. A 3-compartment model with melatonin elimination from the central compartment was used to describe the data. The values (mean +/- SD) for the cows and the goats were: elimination half-life 27 +/- 4 min and 27 +/- 1 min, mean residence time 24 +/- 4 min and 18 +/- 4 min, steady state distribution volume 1.0 +/- 0.3 l/kg and 0.6 +/- 0.1 1/kg (p < 0.05), and plasma clearance 0.044 +/- 0.004 l/kg/min and 0.035 +/- 0.011 l/kg/min, respectively. Following injection, the melatonin concentration in milk increased rapidly and exceeded the corresponding serum value 15-30 min later, remaining thereafter above the serum level. Our results suggest that milk melatonin levels reflect blood concentrations of melatonin with a short delay.

Animal Husbandry↗
PubMed1997

Plasma interleukin-8, interleukin-10, and E-selectin levels in neutropenic and non-neutropenic bacteremic patients.

Plasma interleukin-8 (IL-8) interleukin-10 (IL-10), and E-selectin concentrations were studied in 39 neutropenic and 30 non-neutropenic bacteremic patients; 54 nonbacteremic patients were analyzed as controls. Interleukin-8 concentrations were significantly higher in neutropenic than in non-neutropenic bacteremic patients (median 475 vs. 0 pg/ml, p < 0.0001). Median IL-8 and IL-10 levels were higher in bacteremic than in non-bacteremic patients (330 vs. 0 pg/ml, p < 0.0001 and 20 vs. 0 pg/ml, p = 0.04, respectively). In contrast, concentrations of IL-10 were similar in neutropenic and non-neutropenic patients. Median levels of E-selectin were not increased in any of the patient groups. Neutropenic bacteremic patients showed significantly lower concentrations of E-selectin than did non-neutropenic bacteremic patients (p < 0.0001). In conclusion, neutropenic bacteremic patients had significantly higher concentrations of IL-8 than non-neutropenic bacteremic patients. Levels of IL-10 were higher in bacteremic than in nonbacteremic patients, but neutropenic and non-neutropenic patients had similar levels of IL-10. Increased levels of E-selectin were not found in any of the patient groups, although neutropenic patients with bacteremia had lower concentrations than did non-neutropenic patients.

Adult↗
PubMed1997

Effect of continuous venovenous haemofiltration and haemodiafiltration on the elimination of fluconazole in patients with acute renal failure.

The elimination of fluconazole was studied in six patients with acute renal failure undergoing continuous venovenous haemofiltration (CVVH) for 24 h, continuous venovenous haemodiafiltration (CVVHD) 1 L/h for 24 h and CVVHD 2 L/h for 24 h. Fluconazole 200 mg once daily was given intravenously on three successive days and the concentrations of fluconazole in serum, ultrafiltrate/dialysate and urine were determined for 24 h after each dose. The half-life of fluconazole in patients during CVVH (83.5 +/- 30.1 h; mean +/- S.D.) was significantly (P < 0.05) longer than that during CVVHD 1 L/h (30.4 +/- 5.0 h) or CVVHD 2 L/h (21.8 +/- 3.5 h). The total fluconazole clearance was 0.57 +/- 0.16 L/h, 1.50 +/- 0.24 L/h and 1.85 +/- 0.17 L/h in CVVH, CVVHD 1 L/h and CVVHD 2 L/h, respectively, and there was a significant difference (P < 0.05) between all these treatments. Daily renal excretion of fluconazole was minimal, ranging from 0.002 mg to 11.2 mg in different patients with different treatment modes. The methods tested increased the elimination of the unchanged drug 20- to 400-fold in patients with acute renal failure. Patients undergoing CVVHD therapy with a dialysis flow rates of 1 or 2 L/h should be treated with a daily dose of at least 200 mg of fluconazole to maintain therapeutic drug concentrations. However, in patients on CVVH therapy smaller doses of fluconazole may be enough.

Acute Kidney Injury↗
PubMed1997

Dexmedetomidine as an anesthetic adjunct in coronary artery bypass grafting.

BACKGROUND: Alpha 2-adrenergic agonists decrease sympathetic tone with ensuing attenuation of neuroendocrine and hemodynamic responses to anesthesia and surgery. The effects of dexmedetomidine, a highly specific alpha 2-adrenergic agonist, on these responses have not been reported in patients undergoing coronary artery bypass grafting. METHODS: Eighty patients scheduled for elective coronary artery bypass grafting received, in a double-blind manner, either a saline placebo or a dexmedetomidine infusion, initially 50 ng.kg-1.min-1 for 30 min before induction of anesthesia with fentanyl, and then 7 ng.kg-1.min-1 unit the end of surgery. Filling pressures, blood pressure, and heart rate were controlled by intravenous fluid and by supplemental anesthetics and vasoactive drugs. RESULTS: Compared with placebo, dexmedetomidine decreased plasma norepinephrine concentrations by 90%, attenuated the increase of blood pressure during anesthesia (3 vs. 24 mmHg) and surgery (2 vs. 14 mmHg), but increased slightly the need for intravenous fluid challenge (29 vs. 20 patients) and induced more hypotension during cardiopulmonary bypass (9 vs. 0 patients). Dexmedetomidine decreased the incidence of intraoperative (2 vs. 13 patients) and postoperative (5 vs. 16 patients) tachycardia. Dexmedetomidine also decreased the need for additional doses of fentanyl (3.1 vs. 5.4), the increments of enflurane (4.4 vs. 5.6), the need for beta blockers (3 vs. 11 patients), and the incidence of fentanyl-induced muscle rigidity (15 vs. 33 patients) and postoperative shivering (13 vs. 23 patients). CONCLUSIONS: Intraoperative intravenous infusion of dexmedetomidine to patients undergoing coronary artery revascularization decreased intraoperative sympathetic tone and attenuated hyperdynamic responses to anesthesia and surgery but increased the propensity toward hypotension.

Adjuvants, Anesthesia↗