Evaluation of the recovery of waterborne Giardia cysts by freshwater clams and cyst detection in clam tissue

The Asian freshwater clam, Corbicula fluminea, inhabits environments recognized to be contaminated with waterborne Giardia cysts. Sixty-four tissue samples of Giardia-free clams were spiked with various numbers of Giardia duodenalis cysts within the range of 50–700 cysts. Regression analysis showed that paired numbers of spiked (x) versus recovered (y) cysts regressed significantly (P < 0.01) according to the equation y= 42.57 + 1.81x (±64.3). The cyst detection threshold was 43 cysts/clam, the coefficient of determination was 77%, and the overall sensitivity of cyst detection was 42.9%. All 20 values of cyst numbers in clam tissue samples that were processed blind were located within the 95% prediction limits of the linear regression equation. The cyst retention rate of 160 clams kept in an aquarium with 38 l of water spiked with 1.00 × 10⁵ G. duodenalis cysts was approximately 1.3 × 10³ cysts/clam. No waterborne cysts were detected by the membrane filtration method 90 min after spiking the aquarium water. G. duodenalis cysts were detected in clam tissue up to 3 weeks post-exposure. Filtration of water by clams substantially depleted the aquarium water of its particulate matter. The sampling program demonstrated that the population of 160 clams examined during the study could be accurately assessed for exposure to waterborne Giardia cysts by random sampling of 86 (54%) clams. The results indicate that C. fluminea clams can be used␣for biological monitoring of contamination with Giardia. Received: 27 May 1998 / Accepted: 7 July 1998     

Fate of <Emphasis Type="Italic">Cryptosporidium parvum</Emphasis> and <Emphasis Type="Italic">Cryptosporidium hominis</Emphasis> oocysts and <Emphasis Type="Italic">Giardia duodenalis</Emphasis> cysts during secondary wastewater treatments

This study investigates the fate of Cryptosporidium parvum and C. hominis oocysts and Giardia duodenalis cysts at four Irish municipal wastewater treatment plants (i.e., Plant A, B, C, and D) that utilize sludge activation or biofilm-coated percolating filter systems for secondary wastewater treatment. The fate of these pathogens through the sewage treatment processes was determined based on their viable transmissive stages, i.e., oocysts for Cryptosporidium and cysts for Giardia. Analysis of final effluent indicated that over 97% of viable oocysts and cysts were eliminated, except at Plant C, which achieved only 64% of oocyst removal. A significant correlation between the removal of oocysts and cysts was found at Plants A, B, and D (R = 0.98, P < 0.05). All sewage sludge samples were positive for C. parvum and C. hominis, and G. duodenalis, with maximum concentrations of 20 oocysts and eight cysts per gram in primary sludge indicating the need for further sludge sanitization treatments. This study provides evidence that C. parvum and C. hominis oocysts and G. duodenalis cysts are present throughout the wastewater processes and in end-products, and can enter the aquatic environment with consequent negative implications for public health.     

Giardia and other intestinal parasites in dogs from veterinary clinics in Japan

The present study is the first report that describes the national survey of intestinal parasites in private household dogs brought to veterinary clinics in Japan. A total of 2,365 fresh feces were collected. Giardia-specific coproantigen was examined by ELISA kit (SNAP^? Giardia, IDEXX Laboratories, Inc.; Maine, USA). Other intestinal parasites were determined microscopically using the formalin–ethyl acetate sedimentation technique. According to age categories, Giardia duodenalis, Cystoisospora spp., Toxocara canis, Toxascaris leonina, and Strongyloides spp., at ≦6-months-old showed significantly (P < 0.0001, P < 0.001 or P < 0.01, respectively) higher prevalence compared to >6 months old (31.5% vs. 2.3%, 9.1% vs. 0.05%, 1.8% vs. 0.4%, 1.1% vs. 0%, and 1.1% vs. 0.05%, respectively). In clinical categories, prevalences of G. duodenalis (14.8%) and Cystoisospora spp. (4.7%) in symptomatic dogs were significantly (P < 0.05, respectively) higher than those in asymptomatic ones (7.9% and 1.6%, respectively). G. duodenalis and Cystoisospora spp. were dominant parasites in private household dogs in Japan, especially ≦6-month-old dogs.     

Occurrence of <Emphasis Type="Italic">Cryptosporidium parvum</Emphasis> and <Emphasis Type="Italic">Giardia duodenalis</Emphasis> in healthy adult domestic ruminants

To determine the prevalence and intensity of infection of Cryptosporidium spp. and Giardia duodenalis in healthy adult domestic ruminants, faecal samples were collected from 379 cattle of between 3 and 13 years old, 446 sheep and 116 goats selected at random from 60 dairy farms and 38 and 20 herds, respectively, in Galicia (NW Spain). Cryptosporidium spp. oocysts were detected in 32 cows (8.4%), 24 sheep (5.3%) and in nine goats (7.7%) from, respectively, 48.3% of the farms and 34.2 and 30.0% of the herds. The intensity of infection in cows ranged between 25 and 5,924 oocysts per gram of faeces (OPG), whereas in sheep and goats, the number of oocysts shed ranged from 8–515 OPG and from 17–782 OPG, respectively. Parasitization by Cryptosporidium spp. was significantly higher (P < 0.05) in cows than in sheep and goats. G. duodenalis cysts were identified in 101 cows (26.6%), 86 sheep (19.2%) and 23 goats (19.8%) from, respectively, 96.6% of the farms and 92.1 and 90% of the herds. The number of cysts shed by cows ranged between 15 and 3,042 cyst per gram of faeces (CPG), whereas the intensity of infection in sheep and goats ranged from 16–3010 CPG and from 15–1845 CPG, respectively, and was significantly lower (P < 0.05) than in cows and sheep. The number of Cryptosporidium spp. oocysts isolated from sheep and goats was insufficient for successful polymerase chain reaction analysis. Nevertheless, gene sequence analysis of the hsp70 and 18SrRNA genes of Cryptosporidium revealed the presence of only C. parvum in faecal samples from cows. Genotyping studies of the β-giardin and glutamate dehydrogenase genes of G. duodenalis revealed mainly assemblage E of Giardia in cows, sheep and goat faecal samples. Assemblage B of G. duodenalis was also detected in one sheep sample. These animals should be considered as a possible source of cryptosporidiosis and giardiosis, thereby maintaining the infections on farms and in herds.     

Genotyping of <Emphasis Type="Italic">Giardia duodenalis</Emphasis> isolates among residents of slum area in Manila,Philippines

Giardia duodenalis is a flagellated protist that causes gastrointestinal disease throughout the world. In the Philippines, study on G. duodenalis is limited. It is also believed that prevalence rates of this organism in the country are underestimated. In this study, stool samples from residents living in a slum area in Manila were collected. These were examined under microscopy for identification of common helminthic and protistan parasites. Results showed that 22.05% of 2,354 stool samples collected contained Giardia cysts. A fraction of samples (n = 133) positive for Giardia cysts were set aside. Genomic DNA was extracted from these samples and a polymerase chain reaction-restriction fragment length polymorphism procedure based on the organism’s triose phosphate isomerase gene was utilized. This particular procedure is capable of distinguishing assemblages or genotypes within G. duodenalis. The highest identified assemblage was Assemblage B (86.47%). The two genotypes of Assemblage A were also detected. This is the first report on the identification of genotypes of G. duodenalis in the Philippines. The results of this study can serve as basis for future control and prevention of giardiasis and parasitism in the country.     

Factors affecting the incidence of cystic ovaries in replacement gilts

The aim of the present study was to investigate the incidence of cystic ovaries in replacement gilts in relation to age, body weight, estrus behavior, season, and reasons for culling. Data and genital organs of 336 slaughtered gilts from six commercial herds in Thailand were investigated. The reproductive organs were collected at the slaughter house and transported on ice to the laboratory within 24 h for post-mortem examination. Cystic ovaries were characterized by the presence of single or multiple cysts whether accompanied by any other normal structure or not. Cystic ovaries were observed in 44 of 336 (13.1%) gilts. Of these gilts, 26 (59.1%) gilts had multiple cysts and 18 (40.9%) gilts had single cysts. Gilts culled due to abnormal vaginal discharge were more likely to have cysts than gilts culled due to anestrus (19.4% versus 9.1%, P = 0.043). The gilts that were culled at a body weight of ≥161 kg had a higher incidence of cystic ovaries than gilts culled at a body weight of ≤130 kg (8.1% versus 20.3%, P = 0.045). The incidence of cystic ovaries was lower in those that had not shown estrus than those that had shown estrus (5.2% versus 19.7%, P < 0.001). The incidence of cystic ovaries tended to be higher in the gilts culled in cool (18.6%) compared to hot (10.0%, P = 0.092) and rainy (11.4%, P = 0.129) seasons.     

Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in middle-aged and elderly people

Effects of a 24-week strength training performed twice weekly (24 ST) (combined with explosive exercises) followed by either a 3-week detraining (3 DT) and a 21-week re-strength-training (21 RST) (experiment A) or by a 24-week detraining (24 DT) (experiment B) on neural activation of the agonist and antagonist leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris, maximal isometric and one repetition maximum (1-RM) strength and jumping (J) and walking (W) performances were examined. A group of middle-aged (M, 37–44 years, n=12) and elderly (E, 62–77, n=10) and another group of M (35–45, n=7) and E (63–78, n=7) served as subjects. In experiment A, the 1-RM increased substantially during 24 ST in M (27%, P < 0.001) and E (29%, P < 0.001) and in experiment B in M (29%, P < 0.001) and E (23%, P < 0.01). During 21 RST the 1-RM was increased by 5% at week 48 (P < 0.01) in M and 3% at week 41 in E (n.s., but P < 0.05 at week 34). In experiment A the integrated electromyogram (IEMG) of the vastus muscles in the 1-RM increased during 24 ST in both M (P < 0.05) and E (P < 0.001) and during 21 RST in M for the right (P < 0.05) and in E for both legs (P < 0.05). The biceps femoris co-activation during the 1-RM leg extension decreased during the first 8-week training in M (from 29 ± 5% to 25 ± 3%, n.s.) and especially in E (from 41 ± 11% to 32 ± 9%, P < 0.05). The CSA increased by 7% in M (P < 0.05) and by 7% in E (P < 0.001), and by 7% (n.s.) in M and by 3% in E (n.s.) during 24 ST periods. Increases of 18% (P < 0.001) and 12% (P < 0.05) in M and 22% (P < 0.001) and 26% (P < 0.05) in E occurred in J. W speed increased (P < 0.05) in both age groups. The only decrease during 3 DT was in maximal isometric force in M by 6% (P < 0.05) and by 4% (n.s.) in E. During 24 DT the CSA decreased in both age groups (P < 0.01), the 1-RM decreased by 6% (P < 0.05) in M and by 4% (P < 0.05) in E and isometric force by 12% (P < 0.001) in M and by 9% (P < 0.05) in E, respectively, while J and W remained unaltered. The strength gains were accompanied by increased maximal voluntary neural activation of the agonists in both age groups with reduced antagonist co-activation in the elderly during the initial training phases. Neural adaptation seemed to play a greater role than muscle hypertrophy. Short-term detraining led to only minor changes, while prolonged detraining resulted in muscle atrophy and decreased voluntary strength, but explosive jumping and walking actions in both age groups appeared to remain elevated for quite a long time by compensatory types of physical activities when performed on a regular basis. Accepted: 2 May 2000     

Relationships among bather density, levels of human waterborne pathogens, and fecal coliform counts in marine recreational beach water

During summer months, samples of marine beach water were tested weekly for human waterborne pathogens in association with high and low bather numbers during weekends and weekdays, respectively. The numbers of bathers on weekends were significantly higher than on weekdays (P < 0.001), and this was associated with a significant (P < 0.04) increase in water turbidity. The proportion of water samples containing Cryptosporidium parvum, Giardia duodenalis, and Enterocytozoon bieneusi was significantly higher (P < 0.03) on weekends than on weekdays, and significantly (P < 0.01) correlated with enterococci counts. The concentration of all three waterborne pathogens was significantly correlated with bather density (P < 0.01). The study demonstrated that: (a) human pathogens were present in beach water on days deemed acceptable for bathing according to fecal bacterial standards; (b) enterococci count was a good indicator for the presence of Cryptosporidium, Giardia, and microsporidian spores in recreational marine beach water; (c) water should be tested for enterococci during times when bather numbers are high; (d) re-suspension of bottom sediments by bathers caused elevated levels of enterococci and waterborne parasites, thus bathers themselves can create a non-point source for water contamination; and (e) exposure to recreational bathing waters can play a role in epidemiology of microsporidiosis. In order to protect public health, it is recommended to: (a) prevent diapered children from entering beach water; (b) introduce bather number limits to recreational areas; (c) advise people with gastroenteritis to avoid bathing; and (d) use showers prior to and after bathing.     

Echinococcus granulosus: membrane permeability of secondary hydatid cysts to albendazole sulfoxide

The objectives of the present study were, first, to establish a methodology for evaluation of the permeability in vitro of hydatid cysts to different drugs and, second, to compare the permeability to albendazole sulfoxide of cysts from untreated animals, cysts from animals treated with 50 mg/kg netobimin for 5 days, and cysts from animals treated with 50 mg/kg netobimin plus 1.1 mg/kg fenbendazole for 5 days. The drug flow follows the Fick law, i.e., the uptake occurs by simple diffusion. We calculated the permeability constant of the cyst membrane by taking into account the disappearance velocity constant, the cyst area, and the incubation solution volume. The permeability value obtained for albendazole sulfoxide was 8.06 ± 2.30 × 10⁻⁶ cm s⁻¹ in cysts from untreated animals, 5.56 ± 2.53 × 10⁻⁶ cm s⁻¹ in cysts from animals treated with netobimin, and 7.05 ± 3.04 × 10⁻⁶ cm s⁻¹ in cysts from animals treated with netobimin + fenbendazole. These permeability values show significant differences (P < 0.05). Received: 20 September 1997 / Accepted: 15 October 1997     

Central fatigue explains sex differences in muscle fatigue and contralateral cross-over effects of maximal contractions

A sustained voluntary contraction increases central fatigue and produces a ‘cross-over’ of fatigue during a subsequent contraction of the contralateral limb. These studies compared the magnitude of these changes for men and women. Force and electromyographic responses from dominant (study 1; n = 8 men, 8 women) or non-dominant (study 2; n = 7 men, 8 women) leg extensors to nerve stimulation were recorded at rest and during brief maximal voluntary contractions (MVCs), before and after 100-s sustained MVCs performed with the dominant leg. For the dominant leg, force was reduced more for men (by ∼24%) than women (by ∼16%, P < 0.05) after the sustained contractions. Similarly, voluntary activation during these contractions was reduced more for men (by ∼22%) than women (by ∼9%, P < 0.05). Conversely, resting twitches changed similarly for both sexes (P > 0.05). For the non-dominant leg, men experienced a reduction in force (by ∼13%, P < 0.001) and had greater deficits in activation than women (∼9% vs ∼3%, P < 0.05), after sustained contractions of the dominant leg. Therefore, sustained MVCs produce greater central fatigue and a more pronounced ‘cross-over’ of effects to the contralateral limb for men compared to women. These findings demonstrate distinct differences between sexes in the way the nervous system adapts to changes associated with fatigue.     

Alterations in the expression and activity of creatine kinase-M and mitochondrial creatine kinase subunits in skeletal muscle following prolonged intense exercise in rats

Creatine kinase (CK) isoenzymes are important structural and energy metabolism components in skeletal muscle. In this study, CK isoenzyme alterations were examined in male rats, with an 8% body mass weight attached to their tail. The rats were either forced to swim for 5 h (5S, n = 51), or were pre-trained for 8 days and then forced to swim for 5 h (T5S, n = 48). Rats were sacrificed either immediately (0 h PS), 3 h (3 h PS), or 48 h post-swimming (48 h PS). Serum CK was increased significantly (P < 0.01) 6.2- and 2.0-fold at 0 h PS following the 5S and T5S protocols, respectively. However, training (T5S protocol) significantly (P < 0.01) decreased CK release. Soleus and white gastrocnemius (WG) CK activity was significantly decreased following the 5S protocol (P < 0.05), but not following the T5S protocol. The CK-M activity of the soleus muscle was significantly (P < 0.05) decreased at 0 h PS following both the 5S and T5S protocols, and returned to control values at 3 h PS. The CK-M activity of the WG was significantly (P < 0.05) decreased at 0 h PS following the 5S protocol. Sarcomeric mitochondrial CK (sCK-Mit) was decreased significantly (P < 0.01) at 0 h PS (20%), 3 h PS (14%), 24 h PS (22%), and 48 h PS (15%) following the 5S protocol. However, sCK-Mit was decreased significantly (P < 0.01) only at 0 h PS (7%) following the T5S. The results of this study demonstrate that prolonged intense exercise causes a loss of skeletal muscle CK-M and sCK-Mit activity and that training prior to the prolonged intense exercise attenuates the exercise-induced CK-M and sCK-Mit loss in both red and white skeletal muscles. Accepted: 18 July 1999     

Characteristics of <Emphasis Type="Italic">Streptococcus bovis</Emphasis> endocarditis and its differences with <Emphasis Type="Italic">Streptococcus viridans</Emphasis> endocarditis

The purpose of this study was to evaluate the characteristics of infective endocarditis (IE) caused by S. bovis and compare them to those caused by streptococci of the viridans group (SVG). A prospective study was undertaken considering 55 consecutive cases of IE due to S. bovis and 41 to SVG over 18 years. The study was divided into two periods (1988–1996 and 1997–2005). S. bovis caused 24% of the IE in our centre and constituted the main aetiology for this disease, showing an increase of 358% during the second period studied. Biotype I was responsible for 94.5% of cases and there was a high degree of association with colon tumours (53%). Over the period of the study, 107 patients admitted to our hospital had bacteraemia caused by S. bovis and 310 patients had bacteraemia caused by SVG. In the first group, 55 (51%) were endocarditis cases, but only 41 (13%) of the patients with SVG bacteraemia had endocarditis (p < 0.0001). The distinguishing features of endocarditis caused by S. bovis in comparison with those caused by SGV were: a greater increase in cases during the 2nd period studied (from 12 to 43 vs. from 19 to 22, p < 0.01), a higher percentage of males (93% vs. 71%, p < 0.004), patients significantly older (median age 66 vs. 58.5, p < 0.004), less predisposing cardiopathy (42% vs. 76%, p < 0.0009), more bivalvular involvement (42% vs. 22%, p < 0.04), more spondylitis (9% vs. 0%, p < 0.04), a higher association with colonic tumours (53% vs. 5%, p < 0.0001), and a higher percentage of antibiotic resistance: erythromycin 66% vs. 19%, p < 0.0001; clindamycin 67% vs. 11%, p < 0.0001; cotrimoxazole 77% vs. 30.5%, p < 0.0001, respectively. IE due to S. bovis is an emergent disease in our environment, presenting different characteristics to those produced by SVG.     

Fractional use of anaerobic capacity during a 30- and a 45-s Wingate test

This study examined the suitability of the Wingate test as a means of assessing the maximal oxygen deficit (MOD), and the influence of the anaerobic capacity on the fraction of the MOD used during a 30- and a 45-s Wingate test in 19 male subjects. The MOD incurred in constant-intensity supramaximal exercise was higher (P < 0.01) than that for the 45-s and 30-s Wingate tests [68.6 (3.4) vs 60.9 (2.2) and 53.7 (1.6) ml · kg⁻¹, respectively], corresponding to a 10% higher value for the 45-s compared to that for the 30-s test (P < 0.001). A close correlation was found to occur between MOD and the oxygen deficit incurred during the 30- and 45-s Wingate tests, as well as between both all-out tests (r = 0.86–0.90; P < 0.001). The oxygen deficit accumulated during the first 30 s of the 45-s Wingate test was similar to that accumulated during the 30-s Wingate test. The intraclass correlation coefficient for the oxygen deficit after 30 s of all-out exercise (two treatments) was 0.96. The higher the MOD the lower was its fractional recruitment during the 30-s (r = −0.88, P < 0.001) and during the 45-s (r = −0.74, P < 0.01) Wingate tests. In conclusion, 80–90% as an assessment of the oxygen deficit incurred during a Wingate test is valid as an estimate of the anaerobic capacity. The fraction of the anaerobic capacity used in a 30- and 45-s all-out test in inversely related to the anaerobic capacity. Accepted: 15 April 1997     

Thyroid hormones and their correlations with serum glucose, beta hydroxybutyrate, nonesterified fatty acids, cholesterol, and lipoproteins of high-yielding dairy cows at different stages of lactation cycle

The relationships between circulating thyroid hormones and serum glucose, beta hydroxybutyrate (BHB), nonesterified fatty acid (NEFA), cholesterol and lipoproteins of high-yielding dairy cows were studied in 125 adult Holsteins at various stages of lactation cycle: early (far-off) dry period (n = 24), late (close-up) dry period (n = 10), fresh cows (n = 22), early lactation (n = 13), mid-lactation (n = 27) and late lactation (n = 29). Decreased levels of thyroxin (T₄) and triiodothyronine (T₃) were noted in peripartum cows which were extended to mid- and late-lactation cows, respectively. In fresh cows, glucose showed correlations with T₄ (r = 0.619, P < 0.01) and T₃ (r = 0.627, P < 0.01). In the same cows there were correlations between T₄ and BHB (r = 0.590, P < 0.01) and NEFA (r = 0.470, P < 0.01). In late dry cows, free thyroxin (fT₄) showed correlations with triglyceride (TG) and very-low-density lipoprotein (VLDL; r = −0.638, P < 0.05). Pooled data of the various stages of lactation cycle revealed correlations between glucose and T₄ (r = 0.20, P < 0.05), glucose and T₃ (r = 0.395, P < 0.01), cholesterol and T₃ (r = −0.201, P < 0.05), and free triiodothyronine (fT₃) and high-density lipoprotein (HDL; r = 0.178, P < 0.05). It appears that the time and the pattern of changes and/or correlations of serum thyroid hormones and lipid fractions may vary among dairy cows and other animals.     

Effects of different dietary prebiotic inulin levels on blood serum enzymes, hematologic, and biochemical parameters of great sturgeon (Huso huso) juveniles

An 8-week growth trial was carried out in freshwater fiberglass tanks to investigate the effects of different dietary prebiotic inulin levels on hematologic and biochemical parameters and some blood serum enzymes in juvenile great sturgeon (Huso huso). Four experimental diets were formulated to contain different prebiotic inulin levels (0.0%, 1.0%, 2.0%, and 3.0%, respectively). Triplicate groups of fish (50 fish per tank with an average body weight of 16.14 ± 0.38 g) were assigned to each diet. Blood samples were taken from the caudal vein of 60 apparently healthy fish at the end of the trial. No significant differences were observed in serum enzymes between the treatment groups (P > 0.05). The results show that with the increase in supplementation level of inulin, the mean values of alkaline phosphatase decreased but the mean value of other enzymes increased. white blood cell count increased significantly in group treated with 1% inulin compared with the other groups (P < 0.05). No significant difference between the treatment groups was observed in some hematologic and biochemical parameters such as red blood cell count, mean corpuscular hemoglobin (MCH), and glucose (P > 0.05). With the increase supplementation level of inulin, the mean values of cholesterol, MCH, and MCH concentration increased, but the mean value of glucose, white blood cell count, red blood cell count, hematocrit, hemoglobin, and mean corpuscular volume decreased.     

Nephropathia epidemica and leptospirosis in Champagne-Ardenne,France: comparison of clinical,biological and epidemiological profiles

In the present retrospective study, we described a series of 45 non-icteric leptospirosis and 44 nephropathia epidemica (NE) patients diagnosed in the northeast of France from 1995 to 2005 and compared their clinical picture and laboratory parameters, as well as some epidemiological data. Loin pain (P < 0.001), abdominal pains (P = 0.007), rise of blood pressure (P < 0.001) and pharyngitis (P = 0.01) were more frequently found in NE patients. Aspartate aminotransferase (ASAT) (P = 0,006), creatine phosphokinase (CPK) (P < 0.0001) and C-reactive protein (CRP) (P < 0.0001) were higher in leptospirosis, whereas creatinine (P = 0.009) was higher in NE. Leptospirosis mainly concerns occupational hazards, e.g. farmers, and leisure activities like swimming, and NE concerns professional foresters or leisure activities in the forest and the cleaning of attics. During hospitalisation, patients receiving antibiotics were more frequent among leptospirosis than among NE patients (80% versus 59%, P = 0.06). Among the various common clinical signs, only acute myopia appeared to be a pathognomonic but inconsistently observed clinical sign, which was only observed in 47% of NE cases.     

Cardiac, arterial and venous adaptation to weightlessness during 6-month MIR spaceflights with and without thigh cuffs (bracelets)

The objectives of this investigation were to study the effects of thigh cuffs (bracelets) on cardiovascular adaptation and deconditioning in 0 g. The cardiovascular parameters of six cosmonauts were measured by echocardiography, Doppler, and plethysmography, during three 6-month MIR spaceflights. Measurements were made at rest during preflight (−30 days), inflight (1, 3–4, and 5–5.5 months) without cuffs (morning) and after 5 h with cuffs, and during postflight (+3 and +7 days). Lower-body negative pressure (LBNP) measurements were performed 1 day after each resting session. Inflight values of left ventricle end-diastolic volume and stroke volume measured without the thigh cuffs (−8 to −24% and −10 to −16%, respectively, both P < 0.05) were lower than corresponding preflight values. The jugular and femoral vein cross-sectional areas (A _jv and A _fv, respectively) were enlarged (A _jv: by 23–30%, P < 0.001; A _fv: by 33–70% P < 0.01). The renal and femoral vascular resistances (R _ra and R _fa, respectively) decreased (R _ra: by −15 to −16%, P < 0.01; R _fa: by −5 to −11%, P < 0.01). Inflight, the thigh cuffs reduced the A _jv (by −12 to −20%, P < 0.02), but enlarged the A _fv (A _fv: by 9–20%, P < 0.02) and increased the vascular resistance (R _ra: by 8–13%, P < 0.05; R _fa: by 10–16%, P < 0.01) compared to corresponding inflight, without-cuffs values. During LBNP (−45 mmHg, where 1 mmHg=133.3 N/m²), R _fa and the ratio between cerebral and femoral blood flow (Q˙ _ca/Q˙ _fa) increased less inflight and postflight (+25% for R _fa and +30% for Q˙ _ca/Q˙ _fa) than during preflight (60% for R _fa and 75% for Q˙ _ca/Q˙ _fa, P < 0.01). This reduced vasoconstrictive response and less efficient flow redistribution toward the brain was associated with orthostatic intolerance during postflight stand tests in all of the cosmonauts. The calf circumference increased less inflight and postflight (6% P < 0.05) than preflight (9% P < 0.05). The vascular response to LBNP remained similarly altered throughout the flight. The thigh cuffs compensated partially for the cardiovascular changes induced by exposure to 0 g, but did not interfere with 0 g deconditioning. Accepted: 5 November 1999     

Comparative study on determination of plasma thyroid hormones by chemiluminescence and electrochemiluminescence immunoassay methods in sheep

The aim of this study was to compare plasma thyroid hormone concentrations by both chemiluminescence (CLIA) and electrochemiluminescence immunoassay (ECLIA) methods in sheep. Blood samples were taken from the jugular vein of 25 clinically healthy, non-pregnant adult ewes. The plasma was analyzed to determine thyroxine (T₄), tri-iodothyronine (T₃), free thyroxine (fT₄) and free tri-iodothyronine (fT₃) concentrations. The data from this study indicates, there were significant differences in the T₄ (P < 0.0001), T₃(P < 0.01) and fT₃(P < 0.01) concentrations between the two methods, and the levels of these hormones were higher when using the ECLIA method. In determining thyroid hormones using the CLIA and ECLIA methods, significant positive correlations were found between T₄ and fT₄ (P < 0.001, r = 0.703; P < 0.0001, r = 0.806) also between T₃ and fT₃ (P < 0.0001, r = 0.922; P < 0.0001, r = 0.923) concentrations, respectively. The linear regression analysis of these hormones showed that the CLIA and ECLIA results were significantly correlated (T₄ (P < 0.01, r = 0.583), T₃ (P < 0.0001, r = 0.898), fT4 (P < 0.0001, r = 0.796) and fT₃ (P < 0.0001, r = 0.898).     

Mitochondrion-rich differentiated adenocarcinomas of the stomach: clinicopathological, immunohistochemical and electron microscopy study of nine cases

Pathologic and prognostic data of nine patients with mitochondrion-rich carcinomas (MRC) were compared retrospectively to data of 101 patients with conventional gastric adenocarcinomas. MRC was defined as a tumour composed predominantly, or entirely, of columnar adenocarcinoma cells with eosinophilic cytoplasm and a strong supranuclear immunoreactivity for antimitocondrial antibody. Electron microscopy confirmed supranuclear distribution of mitochondria in MRC while immunostaining pattern was irregular or absent in the remaining 101 cases. MRC exhibited a tubulopapillary or cribriform growth pattern with focal infiltration of neutrophils in the tumour stroma. Prominent necrosis was present including segmental and intraluminal “dirty necrosis”, while mitotic and ki-67 proliferative rates were low. MRC showed immunohistochemical findings compatible with gastric differentiation (CK7⁺/CK20⁻/CDX⁻).When MRC were compared with non-MRC carcinomas, tumour size (<4 cm vs >4 cm, P < 0.01), frequency of lymph node metastases (11% vs. 80%, P < 0.01), low stage (I, II) at diagnosis (100% vs. 56%, P < 0.01), Goseki’s group I (100% vs. 6%, P < 0.01), and better survival (0% vs. 70%, P < 0.01) differed significantly. Our results suggest that MRC of the stomach may be considered a low-grade malignancy with an excellent prognosis.     

Effects of heavy resistance training on maximal and explosive force production, endurance and serum hormones in adolescent handball players

To determine the effects of 6-weeks of heavy-resistance training on physical fitness and serum hormone status in adolescents (range 14–16 years old) 19 male handball players were divided into two different groups: a handball training group (NST, n = 10), and a handball and heavy-resistance strength training group (ST, n = 9). A third group of 4 handball goalkeepers of similar age served as a control group (C, n = 4). After the 6-week training period, the ST group showed an improvement in maximal dynamic strength of the leg extensors (12.2%; P < 0.01) and the upper extremity muscles (23%; P < 0.01), while no changes were observed in the NST and C groups. Similar differences were observed in the maximal isometric unilateral leg extension forces. The height of the vertical jump increased in the NST group from 29.5 (SD 4) cm to 31.4 (SD 5) cm (P < 0.05) while no changes were observed in the ST and C groups. A significant increase was observed in the ST group in the velocity of the throwing test [from 71.7 (SD 7) km · h⁻¹ to 74.0 (SD 7) km · h⁻¹; P < 0.001] during the 6-week period while no changes were observed in the NST and C groups. During a submaximal endurance test running at 11 km · h⁻¹, a significant decrease in blood lactate concentration occurred in the NST group [from 3.3 (SD 0.9) mmol · l⁻¹ to 2.4 (SD 0.8) mmol · l⁻¹; P < 0.01] during the experiment, while no change was observed in the ST or C groups. Finally, a significant increase (P < 0.01) was noted in the testosterone:cortisol ratio in the C group, while the increase in the NST group approached statistical significance (P < 0.08) and no changes in this ratio occurred in the ST group. The present findings suggested that the addition of 6-weeks of heavy resistance training to the handball training resulted in gains in maximal strength and throwing velocity but it compromised gains in leg explosive force production and endurance running. The tendency for a compromised testosterone:cortisol ratio observed in the ST group could have been associated with a state of overreaching or overtraining. Accepted: 22 April 1999