Validation of a new telemetric core temperature monitor

The purpose of this study was to validate the accuracy and acceptability of the new VitalSense^® telemetric physiological monitoring system (Mini Mitter Co., Inc., Bend, OR). It consists of a receiver/monitor and a thermistor-based ingestible capsule for core body temperature measurement. For comparison, each subject was also monitored with a standard thermistor probe inserted 11 cm beyond the anal sphincter (Mini-Logger^® Series 2000). Both the measurement systems have specified accuracy of ±0.1 °C.

Ten volunteers, four females, six males, mean age 51.1±11.8 years, gave informed consent to wear the two systems for the duration of the passage of the temperature capsule through their digestive tracts. Minute-by-minute comparisons were made between the temperatures recorded by the two systems. Parameters reported include: average transit time of the capsule; temperature at each minute of the experiment; mean difference in temperature at each time point; correlation coefficient for the two temperature measurements; and number of missed data points for each system.

Mean capsule transit time was 48.6±35.5 h with a range of 12.4–136.2 h. The mean temperature for all subjects was 36.93 °C±0.15 °C and 36.96 °C±0.16 °C for the capsule and rectal probe respectively, with no significant difference between the means. The mean difference between readings (capsule–rectal probe) was 0.04 °C±0.03 °C. There was a significant correlation between the capsule and rectal probe temperatures, R²=0.80,p<0.05 and R²=0.90,p<0.05 for all data points and quiescent periods respectively. Of the average 2916±2132 data points per subject, there was a significant (p<0.05) difference in data points lost, 105±120 with VitalSense vs. 449±697 with the rectal probe. The percentage of missing data points was 3.1%±2.5% for the capsule (monitor out of the one-meter range of the capsule) and 11.4%±15.9% for the rectal probe (primarily due to probe slippage, but also due to removal for personal hygiene). The data support the finding that the VitalSense core body temperature monitoring system is at least as accurate as rectal probe monitors and the subjects found it to be much more acceptable.     

Molybdenum balance in healthy young Japanese women

The absorption and balance of molybdenum (Mo) were examined in 43 healthy young Japanese women in four metabolic studies performed once a year from 2001 to 2004. In each year, an 18-d metabolic study, including two successive balance study sessions of 4 d, was designed and four kinds of dietary menus were supplied to the subjects periodically. Since the protein sources of the menus were specified in 2001–2003, and soybean products were poor in 2001 and 2002 and rich in the 2003, Mo intake in 2001 and 2002 was about 150 μg/d while that in 2003 reached 318 μg/d. In 2004, the protein sources were not specified and Mo intake was 217 μg/d. This range of Mo intake overlapped that in the Japanese population. When the results of the four studies were pooled, Mo balance was calculated as 0.09±0.37 μg/d/kg (mean±SD), and no significant relationship (r=0.142) was observed between the intake and balance. Between the apparent absorption (Y) and the intake (X), a significant (r=0.988, p<0.001) positive linear regression (Y=0.927X-0.523) was observed. Similarly, a significant (r=0.960, p<0.001) positive linear regression was observed between Mo intake and urinary excretion. These results indicate that more than 90% of Mo contained in a routine dietary menu is absorbed, most of Mo absorbed is excreted in urine, and Mo balance is in equilibrium in the general Japanese population.     

Investigating high-amplitude oscillations in rat tail skin blood flow during core heating and cooling

In a separate paper, we describe high-amplitude oscillations in human skin blood flow (Q˙_sk). Using an open-loop model in rats, we independently modulated and clamped hypothalamic and skin temperatures. Central heating reliably induced these high-amplitude oscillations in tail Q˙_sk, which occurred at 0.41±0.03 Hz spanning 758.1±25.7 ms, and were comprised of high-amplitude peaks (496.8±87.6 AU) arising from a stable baseline (114.1±27.6 AU). Central cooling significantly reduced Q˙_sk, but not the amplitude, the frequency, width or baseline of the oscillations. These observations indicate that such high-amplitude oscillations are not primarily mediated via central thermal state. Instead, we believe these oscillations to be turned on by an elevated skin temperature.     

Effects of CO2-bath immersion (100 ppm) on thermoregulatory responses in humans

The effects of CO₂ (100 ppm) bathing were investigated. It was found that the chest blood flow, chest sweat rate and tympanic temperature were significantly greater during the immersion in CO₂ bathing than in freshwater bathing (P<0.05). Thus, CO₂ bathing at 100 ppm could produce cutaneous vasodilatation in the immersed skin, affecting thermoregulation.     

Atorvastatin, a potent HMG-CoA reductase inhibitor, is not antipyretic in rats

1. We investigated whether atorvastatin, a plasma cholesterol lowering and anti-inflammatory drug, attenuates lipopolysaccharide-induced fever in rats.

2. Sprague–Dawley rats, implanted with abdominal temperature-sensitive telemeters, were administered either lipopolysaccharide and placebo (n=7), lipopolysaccharide and atorvastatin (n=6), saline and placebo (n=8), or saline and atorvastatin (n=7).

3. Atorvastatin (100 mg kg⁻¹) was administered orally, as a suspension in a flavoured gelatine cube (placebo cubes contained no drug), 90 min before intraperitoneal injection of pyrogen (Salmonella typhosa lipopolysaccharide, 75 μg kg⁻¹) or sterile saline.

4. Atorvastatin did not disrupt normal thermoregulation. Atorvastatin also did not attenuate lipopolysaccharide-induced changes in body temperature and cage activity.

A randomized, double-blind, placebo-controlled, clinical dose–response trial of an extract of Baptisia, Echinacea and Thuja for the treatment of patients with common cold

The aim of this study was to verify the efficacy and safety of an herbal medication containing an extract of a mixture of Baptisiae tinctoriae radix, Echinaceae pallidae/purpureae radix and Thujae occidentalis herba (SB-TOX) in the treatment of upper respiratory tract infections (URIs), and to test whether SB-TOX's clinical efficacy is dose dependent. A total of 91 adults (mean age 42.1±13.0 years) were randomised to receive 19.2 mg of SB-TOX (n=31), 9.6 mg SB-TOX (n=29) or placebo (n=31) three times daily for 3–12 days. Since a “running nose” is the main symptom of a common cold, the total number of facial tissues used throughout the clinical duration of their cold was the primary efficacy parameter. In the intention-to-treat analysis, this total number of tissues decreased with increasing extract dose. The slope across groups according to the Jonckheere test was significant (p=0.0259). In the high-dose group, the standardised effect size Δ/SD was 0.46 compared with placebo. Time to relevant improvement in cold symptoms (measured as the time until less than 30 tissues per day were used) was 1.1 days (95% CI 0.52; 1.67), 0.76 days (95% CI 0.28; 1.24) and 0.52 days (95% CI 0.22; 0.82) in the placebo, low-dose and high-dose groups, respectively (p_LogRank=0.0175). No adverse events were reported. This study demonstrates the efficacy and safety of SB-TOX in the treatment of URIs, and that its efficacy is dose dependent.     

Chemomodulatory effects of Terminalia chebula against nickel chloride induced oxidative stress and tumor promotion response in male Wistar rats

Nickel, a major environmental pollutant is a known potent nephrotoxic agent. In this communication we report the chemopreventive effect of Terminalia chebula on nickel chloride (NiCl₂) induced renal oxidative stress, toxicity and cell proliferation response in male Wistar rats. Administration of NiCl₂ (250 μmoL Ni/kg body weight) to male Wistar rats resulted in an increase in the reduced renal glutathione content (GSH), glutathione-S-transferase (GST), glutathione reductase (GR), lipid peroxidation (LPO), H₂O₂ generation, blood urea nitrogen (BUN) and serum creatinine with a concomitant decrease in the activity of glutathione peroxidase (p<0.001). Nickel chloride (NiCl₂) treatment also induced tumor promotion markers, viz., ornithine decarboxylase (ODC) activity and thymidine [³H] incorporation into renal DNA (p<0.001). Prophylactic treatment of rats with T. chebula (25 mg/kg body weight and 50 mg/kg body weight) daily for one week resulted in the diminution of NiCl₂ mediated damage as evident from the down regulation of glutathione content, GST, GR, LPO, H₂O₂ generation, BUN, serum creatinine, DNA synthesis (p<0.001) and ODC activity (p<0.01) with concomitant restoration of GPx activity. Thus, the present investigation suggests that T. chebula extract could be used as therapeutic agent for cancer prevention as evident from this study where it blocks or suppresses the events associated with chemical carcinogenesis.     

Efficacy of a Comfrey root extract ointment in comparison to a Diclo-fenac gel in the treatment of ankle distortions: Results of an observer-blind, randomized, multicenter study

In the treatment of minor blunt injuries several topical drugs are known to have anti-inflammatory and analgesic properties. They represent, however, two fundamentally different major pharmacological therapy approaches: the “chemical-synthetical” and the “phytotherapeutical” approach. The main objective of this trial (CODEC_2004) was to compare the efficacy and tolerability of an ointment of Comfrey extract (Extr. Rad. Symphyti) with that of a Diclofenac gel in the treatment of acute unilateral ankle sprain (distortion). In a single-blind, controlled, randomized, parallel-group, multicenter and confirmatory clinical trial outpatients with acute unilateral ankle sprains (n=164, mean age 29.0 years, 47.6% female) received either a 6 cm long ointment layer of Kytta-Salbe^® f (Comfrey extract) (n=82) or of Diclofenac gel containing 1.16 g of diclofenac diethylamine salt (n=82) for 7±1 days, four times a day.

Primary variable was the area-under-the-curve (AUC) of the pain reaction to pressure on the injured area measured by a calibrated caliper (tonometer). Secondary variables were the circumference of the joint (swelling, figure-of-eight method), the individual spontaneous pain sensation at rest and at movement according to a Visual Analogue Scale (VAS), the judgment of impaired movements of the injured joint by the method of “neutral-zero”, consumption of rescue medication (paracetamol), as well as the global efficacy evaluation and the global assessment of tolerability (both by physician and patient, 4 ranks). In this study the primary variable was also to be validated prospectively.

It was confirmatorily shown that Comfrey extract is non-inferior to diclofenac. The 95% confidence interval for the AUC (Comfrey extract minus Diclofenac gel) was 19.01–103.09 h*N/cm² and was completely above the margin of non-inferiority. Moreover, the results of the primary and secondary variables indicate that Comfrey extract may be superior to Diclofenac gel.     

The anticarcinogenic effect of propolis in human lymphocytes culture

The in vitro anticarcinogenic potential of propolis in human lymphocytes was investigated. Blood samples were obtained from ten healthy males, non-smoking volunteers, which were incubated and exposed to increasing concentrations of propolis (0.01, 0.05, 0.1, 0.2, 0.5, 0.7 and 1.0 ml). The mean micronucleus rates were 1.47±0.38–4.02±0.64. Mitotic index rates were between 19.45±2.22 and 0.28±0.33. The differences between the control and exposed cells were statistically significant (p0.05). We conclude that exposure to different concentrations of propolis cannot produce a carcinogenic effect in peripheral human lymphocytes in vitro. However, increasing micronucleus (MN) rates showed that propolis could have a carcinogenic effect in high concentrations.

Also chemical analysis of propolis sample was evaluated by GC/MS. Propolis sample mainly contains flavonoids, fatty and aromatic acids and their esters.     

Possible sequence of pyrogenic afferent processing in the POA

(1) It is generally considered that fever is modulated in the preoptic-anterior hypothalamic area (POA) in response to signaling by pyrogenic cytokines elaborated in the periphery by mononuclear phagocytes and the consequent induction of prostaglandin (PG)E₂ in the POA. The mechanism of the centripetal transmission of this pyrogenic signal, however, is controversial. One hypothesis suggests that it is conveyed via the vagus to the nucleus tractus solitarius and from there to the POA via the ventral noradrenergic bundle, causing the intraPOA release of norepinephrine (NE) which then stimulates the production of PGE₂. (2) In this article, we review recent data from our laboratory showing that NE microdialyzed into the POA of conscious guinea pigs or injected intracerebroventricularly into conscious mice indeed evokes two distinct core temperature (T_c) rises, viz., one ₁-adrenoceptor (AR)-mediated, rapid in onset and PGE₂-independent, and the other ₂-AR-mediated, delayed and COX-2/PGE₂-dependent. (3) We further present new data suggesting that the febrile response of conscious guinea pigs to intraperitoneally injected lipopolysaccharide (LPS) is mediated by intraPOA NE in accord with the above sequence, i.e., via ₁-AR to initiate the first, PGE₂-independent elevation of T_c, and via ₂-AR to induce the delayed production of COX-2-dependent PGE₂ and the continued rise of T_c. (4) These results thus validate the presumptive involvement of NE in LPS fever induction in guinea pigs.     

Complement is required for the induction of endotoxic fever in guinea pigs and mice

(1) Cobra venom factor (CVF)-induced hypocomplementemia dose-dependently attenuates the febrile responses of guinea pigs and mice to intraperitoneally (ip) but not to intravenously (iv) injected endotoxic bacterial lipopolysaccharide (LPS). (2) Iv but not ip LPS causes fever in complement component 3 (C3) gene-ablated mice, but neither iv nor ip LPS evokes a body core temperature (T_c) rise when WT and these mice's C5a receptors type 1 are blocked. C5 knockout mice also do not develop fever following either iv or ip LPS. C5a thus appears to be a critical mediator of LPS fever. (3) C5 knockouts develop fever in response to intracerebroventricularly (icv) injected LPS or prostaglandin (PG)E₂; the site of action of C5a is therefore peripheral rather than central. (4) The initiation of the febrile responses to both iv and ip LPS is temporally correlated with the appearance of LPS in the liver's Kupffer cells (Kc). (5) PGE₂ is released by liver in immediate response to the injection of CVF into the portal vein of anesthetized guinea pigs; its level rises quickly to its maximum. LPS injected similarly also evokes a quick release of PGE₂ from the liver; it, however, is prevented by prior hypocomplementation. (6) Neither LPS nor IL-1β induces PGE₂ release from Kc in vitro within the first hour after treatment, but serum C and C plus LPS or IL-1β very quickly trigger PGE₂ increases of similar magnitudes, catalyzed non-differentially by cyclooxygenase (COX)-1 and COX-2. Kc would thus appear to be the principal site of action of C5a, inducing the release of PGE₂. (7) PGE₂ is detectable in the plasma of conscious guinea pigs in temporal correlation with the onset of the T_c rise following ip LPS; cytokines appear significantly later. (8) Taken together, these results indicate that LPS-activated C, rather than LPS or IL-1β by itself, triggers PGE₂ release by Kc. This PGE₂ could be the factor that stimulates vagal afferents, thereby providing the signal to the brain that mediates the febrile response.     

Spatial fiber type distribution in normal human muscle: Histochemical and tensiomyographical evaluation

The variability of fiber type distribution in nine limb muscles was examined with histochemical and tensiomyographical (TMG) methods in two groups of 15 men aged between 17 and 40 years. The aim of this study was to determine the extent to which the relative occurrence of different fiber types and subtypes varies within human limb muscles in function to depth and to predict fiber type proportions with a non-invasive TMG method.

The distribution of different fiber types varied within the muscles, as a function of depth, with a predominance of type 2b fibers at the surface and type 1 fibers in deeper regions of the muscle. For all the analyzed muscles the contraction times measured at stimulus intensity 10% of supramaximal stimulus (10% MS) were significantly (p<0.05) shorter than the contraction times measured at 50% of supramaximal stimulus intensity (50% MS). The Pearson's correlation coefficient between percentage of type 1 muscle fibers measured at the surface of the muscle and contraction time at 10% MS, obtained by TMG was statistically significant (r=0.76,P<0.01). Also the Pearson's correlation coefficient between percentage of type 1 muscle fibers measured in the deep region of the muscle and contraction time at 50% MS obtained by TMG was also statistically significant (r=0.90,P<0.001).

These findings suggest that the contraction time obtained by TMG may be useful for non-invasive examining of muscle fiber types spatial distribution in humans.     

Evaluation of the environmental stress index (ESI) for the southern hemisphere

The environmental stress index (ESI), constructed from ambient temperature, relative humidity, and solar radiation, was further evaluated from databases collected in Israel and New Zealand. High correlations were found between ESI and WBGT (R²=0.959 and R²=0.973 for Israel and New Zealand, respectively). However, for the New Zealand database, residuals were not distributed symmetrically around the zero line, which might be due to the difference in the global radiation spectrum. The ultraviolet radiation measurements were significantly higher in New Zealand than in Israel. As a consequence, a correction factor might be needed for ESI to be used in the southern hemisphere.     

Estrogenic effects of two derivatives of icariin on human breast cancer MCF-7 cells

The aims of the present study were to determine the estrogenic activities of icariin (ICA) and its derivatives and their structure–estrogenic activity relationship. Therefore, icaritin (ICT) and desmethylicaritin (DICT) were derived from ICA. The estrogenic activities of ICA, ICT and DICT were examined by cell proliferation and progestogen receptor mRNA expression of estrogen-receptor-positive MCF-7 cells. Current studies exhibited that ICT and DICT both markedly enhanced the proliferation of MCF-7 cells; as compared to estradiol (100%), their relative proliferative effects (RPE) were 90% and 94%, respectively. Cell proliferation induced by ICT and DICT was completely antagonized by ICI182,780. ICT and DICT increased progestogen receptor (PR) at mRNA levels at 48 h after treatment, although the effects were not as prominent as 17β-estradiol (E₂). These phenomena were not observed with ICA. Results demonstrate that ICT and DICT (nonconjugated forms) possess estrogen-like activity; however, ICA appears to have no estrogenicity in the MCF-7 cell line model in vitro.     

Daily rhythms of nonshivering thermogenesis and responses to photoperiod manipulations in Apodemus mystacinus from two different ecosystems

Comparative physiology is an important tool for understanding adaptation to environment. Regulatory nonshivering thermogenesis (NST) is an essential mechanism in small mammals for coping with low ambient temperatures. Because of its geographical location and its sharp climatic changes across short distances, Israel offers conducting comparative studies between different populations of the same species. The aims of this study were: (1) to compare NST-capacity daily rhythms, between the two populations of the broad-toothed field mouse Apodemus Mystacinus—that of Mount Carmel (Mediterranean) and that of Mount Hermon (Subalpinic), (2) to compare the thermoregulatory daily rhythms response to photoperiod manipulations of mice from the two populations.

Mice were acclimated for at least 3 weeks to long scotophase (16D:8L-LS) and then to long photophase (16L:8D-LP) at a constant ambient temperature (T_a) of 24±1 °C. The following variables were compared at four different times of the day (06, 12, 18, 24 h): minimal body temperature (T_bMin), minimal oxygen consumption (VO₂Min) measured at the lower critical point and their response to noradrenaline (NA), 1.5 mg/1 kg.W_b injected s.c., (VO₂NA and T_bNA). NST-capacity was calculated as the ratio between VO₂NA and VO₂Min. The measurements were carried out at T_a of 28 °C and in light conditions matching those of acclimation. NA was injected after establishing VO₂Min and T_bMin. The values mean±SD are given for each measurement for n=6.

A three-way ANOVA revealed a significant difference between the two populations. Significant differences were revealed at different hours within populations under the different photoperiod regimes for different measured variables.     

Modeling the yield of activated sludge in the presence of 2,4-dinitrophenol

In this work, a model was developed to evaluate the yield of activated sludge in the presence of 2,4-dinitrophenol (dNP). Experimental results show that the presence of dNP substantially reduced the sludge yield at all solid retention times tested, but that it had no negative effect on the bioactivity and settleability of activated sludge. With the established model, the maximum observed sludge yield (Y^′_max) and specific endogenous respiration rate (k_d) for the sludge without dNP dose were estimated as 0.79 g-MLSS/g-COD and 0.042 d⁻¹, respectively, whereas for the sludge dosed with dNP the corresponding values were calculated as 0.56 g-MLSS/g-COD and 0.056 d⁻¹, respectively. In the presence of dNP at 5 mg/l, the energy uncoupling coefficient was calculated as 0.29.     

Clinical trial of Cecropia obtusifolia and Marrubium vulgare leaf extracts on blood glucose and serum lipids in type 2 diabetics

Cecropia obtusifolia and Marrubium vulgare have been widely used in Mexican traditional medicine for the control of type 2 diabetes. In order to evaluate the clinical effect produced by the aqueous extract from these species on type 2 non-controlled diabetes mellitus, a total of 43 outpatients were included. Based on the European NIDDM (policy group) criteria, only patients with poor response to the conventional treatment were selected. All patients maintained their medical treatment and also received a prepared infusion of the dry leaves of the plant treatment for 21 days . In a double-blind manner, the patients were randomly grouped as follows: 22 patients were treated with C. obtusifolia and 21 with M. vulgare. The fasting blood glucose values were reduced by 15.25% on patients treated with C. obtusifolia, while cholesterol and triglycerides were decreased by 14.62% and 42.0%, respectively (ANOVA p<0.02). In the case of patients treated with M. vulgare, the plasma glucose level was reduced by 0.64% and cholesterol and triglycerides by 4.16% and 5.78%, respectively. When the results were compared between groups, significant differences in glucose and cholesterol diminution were found. The obtained results showed that the infusion prepared with the leaves of C. obtusifolia (containing 2.99±0.14 mg of chlorogenic acid/g of dried plant) produced beneficial effects on carbohydrate and lipid metabolisms when it was administered as an adjunct on patients with type 2 diabetes with poor response to conventional medical treatment.     

Dispersal, landscape occupancy and population structure in the butterfly Melanargia galathea

Dispersal is a key ecological process linking metapopulation dynamics in the landscape to distribution patterns at larger spatial scales. In this study, we investigated the landscape occupancy and genetic population structure of a butterfly species, Melanargia galathea. Several landscapes differing in composition and structure were sampled as well as populations at different spatial scales. We found that M. galathea occupied 91.3% of all habitat patches available within a particular landscape, probably due to a dominance of landscape scale processes such as rescue effect and recolonisation. A high level of genetic polymorphism within the sampled populations and a very low amount of genetic differentiation between populations was observed (G_st=0.034), characteristic of species with high dispersal capacity and/or high density. High dispersal rates ensured considerable gene mixing at the landscape scale while the influence of distance on dispersal success was detected at the regional and continental scales by a significant amount of isolation by distance. We also found that, at the landscape scale, the dispersal of this butterfly species was influenced by the spatial distribution of its habitat patches.

Zusammenfassung

Die Ausbreitung ist ein ökologischer Schlüsselprozess, der die Metapopulationsdynamik in einer Landschaft mit den Verbreitungsmustern auf einer größeren räumlichen Skala verbindet. In dieser Studie untersuchten wir die Verbreitungsmuster und die genetische Populationsstruktur einer Schmetterlingsart, Melanargia galathea. Es wurden sowohl einige Landschaften beprobt, die sich in der Zusammensetzung und der Struktur unterschieden, als auch Populationen auf verschiedenen räumlichen Skalen. Wir fanden, dass M. galathea 91.3% aller verfügbaren Habitatflecken in einer bestimmten Landschaft besetzte, möglicherweise aufgrund der Dominanz von Landschaftsskalenprozessen wie “Rescue-Effekt” und Rekolonisation. Es wurde ein hoher genetischer Polymorphismuslevel und ein sehr geringer Umfang genetischer Differenzierung innerhalb der beprobten Populationen beobachtet (G_st=0.034), was charakteristisch für Arten mit einer großen Ausbreitungsfähigkeit und/oder hoher Dichte ist. Hohe Ausbreitungsraten sicherten eine beträchtliche Genvermischung auf der Landschaftsskala, während der Einfluss der Entfernung auf den Verbreitungserfolg auf der regionalen und kontinentalen Skala durch einen signifikanten Anteil der Isolation aufgrund von Entfernung festgestellt wurde. Wir fanden auch, dass auf der Landschaftsskala die Ausbreitung dieses Schmetterlings durch die räumliche Verteilung der Habitatflecken beeinflusst wurde.     

Ideal phenotypes and mismatching haplotypes – errors of mtDNA treeing in ants (Hymenoptera: Formicidae) detected by standardized morphometry

A total of 401 nest samples of Formica lugubris Zetterstedt, F. pratensis Retzius, F. aquilonia Yarrow, F. rufa Linnaeus, and F. polyctena Förster, covering the entire Palaearctic range of these species and including 2100 individual workers, was phenotypically investigated by a system of standardized morphometry, pairwise removal of allometric variance, and canonical discriminant functions. A mitochondrial DNA fragment including the cytochrome b gene was sequenced in 148 samples from basically the same range. In the more difficult F. pratensis vs. F. lugubris case, the phenotypic system correctly determined 99.6% of all nest samples, and 95.1% with p<0.05. In all other pairwise species discriminations any nest sample was correctly determined with p<0.01, and three samples with hybrids F. rufa×lugubris were identified. At four localities in the Pyrenees and the Urals, 9 samples with F. pratensis phenotypes (7 of them ideal) but F. lugubris mtDNA haplotypes could be identified, resulting in 14.5% of phenotype/haplotype mismatches. A local dominance of this mismatch combination was observed at one Pyrenean and one Ural locality. There was no indication of an F. pratensis haplotype associated with an F. lugubris phenotype. One ideal F. polyctena phenotype was associated with an F. aquilonia haplotype in a sample from the Urals, and one ideal F. aquilonia phenotype was combined with an F. lugubris haplotype in a sample from central Siberia, resulting in overall phenotype/haplotype mismatch frequencies of 12.5% and 11.1%, respectively. We conclude that all these samples cannot represent actual F₁ hybrids but are the result of hybridizations in the past followed by unidirectional purging of the nuclear genome. Whether this process of purging worked very fast or over longer periods of population history, and whether or not it was complete or incomplete, cannot be assessed from the available information. These facts of hybridizing in two thirds of the W Palaearctic wood ant species, of extreme regional hybrid frequencies (up to 26%), of unidirectional purging of nDNA associated with mismatching mtDNA haplotypes, and of occasional achievement of local dominance of these mismatch combinations, may serve as urgent warning not to perform isolated mtDNA phylogenetic studies without a geographically and locally wide sampling basis and without control by nDNA information or reliable phenotypic determination. The latter two systems definitely have superior significance when conflicts with mtDNA indications arise.