A hidden herbivory effect on Sphagnum reproduction.

Defence theories provide predictions about trade-offs in the allocation of resources to defence and growth. However, very little is known about how pressure from herbivores influences the allocation of resources during reproduction. Two common peatland bryophyte species, Sphagnum angustifolium and S. capillifolium, were chosen as study species. Vegetative and reproductive shoots of both Sphagnum species were subjected to treatments with and without herbivores in a lab experiment. After 4 weeks of exposure to herbivores in a growth chamber, we measured biomass production, net photosynthesis rate, defence traits (phenolics in leachate and phenolics in extract), nonstructural carbohydrates (soluble sugar and starch), and reproductive traits (capsule number, weight and diameter, and spore germination) of both Sphagnum species. Reproductive shoots had higher constitutive defence than vegetative shoots in S. angustifolium, and a similar pattern was observed in S. capillifolium. With herbivory, reproductive shoots showed stronger induced defence (released more phenolics) than vegetative shoots in S. capillifolium, but not in S. angustifolium. Herbivory had no effect on capsule number, weight, or diameter, but reduced spore germination percentage by more than half in both species. Our study highlights the hidden effects of herbivory on reproduction of Sphagnum and indicates the presence of maternal effects in bryophytes. Ecologists will benefit from examining both quality- and quantity-based traits when attempting to estimate the herbivory effect on plant fitness.

Stress radiographic assessment of collateral ligament constraints on the feline tarsocrural joint.

INTRODUCTION: This cadaveric study describes the collateral ligament constraints on the feline tarsocrural joint using stress radiography. METHODS: Thirty-six feline cadaveric hindlimbs free of orthopaedic disease were placed in a custom-made jig and controlled stress radiography was performed before and after transection of one, or both collateral ligaments. Changes in varus and valgus deviation and pronation and supination were measured at three limb angles (extension, 120o flexion and 90o flexion). RESULTS: There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulocalcaneal ligament at all limb positions (extension: 41%, 120°: 78%, 90°: 63%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulotalar ligament at extension (14%). There was a significant positive percentage change in the mean angle of varus deviation after transection of both fibulocalcaneal and fibulotalar ligaments at all limb positions (extension: 58%, 120°: 67%, 90°: 67%), and in the mean angle of valgus deviation (100%) and supination (89%) at 90 degrees flexion. There was a significant positive percentage change in the mean angle of valgus deviation after transection of the tibiocentral ligament at all limb positions (extension: mean 79%, 120°: 43%, 90°: 49%) and the mean angle of pronation at 120 degrees flexion (10%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the tibiotalar ligament at extension (11%) and at 90 degrees flexion (54%) and in the mean angle of pronation at all limb positions (extension: 11%, 120°: 19%, 90°: 32%). There was a significant positive percentage change in the mean angle of valgus deviation (extension: 255%, 120°: 172%, 90°: 176%) and pronation (extension: 58%, 120°: 134%, 90°: 76%) after transection of the tibiocentral and tibiotalar ligaments at all limb positions and in the mean angle of varus deviation at extension (13%) and 90 degrees flexion (69%). CONCLUSION: The medial collateral ligaments prevent against excessive valgus deviation and pronation, and the lateral collateral ligaments prevent against excessive varus deviation and supination. At 90 degrees flexion subluxation of the talus occurs on the ipsilateral side of the ligament injury resulting in an additional direction of instability.

Anatomical investigation of the canine cranial tibial artery.

OBJECTIVE: To investigate arterial vascularity at the level of the proximal tibia as a potential source of the severe intra-operative haemorrhage, which has been previously reported as a complication during tibial plateau levelling osteotomy (TPLO) and triple tibial osteotomy (TTO) surgeries in dogs. To devise a surgical approach for the management of this complication. METHOD: Eight pelvic limbs from five canine cadavers were dissected and the vascular structures at the level of the proximal tibia were identified and photographed. An arterial phase angiogram was performed on a sixth cadaver to further describe the vasculature in situ . Additional dissection was performed on four pelvic limbs to devise a medial surgical approach to the popliteal artery and the cranial tibial artery proximal to the stifle. RESULTS: The cranial tibial artery was identified as the most likely source of profuse haemorrhaging if damaged during proximal tibial osteotomy. Its course and branching are described. A simple medial approach to the popliteal artery at the level of its bifurcation into the cranial and caudal tibial arteries was developed. CLINICAL RELEVANCE: Understanding of the vascular anatomy at the level of the proximal tibia may prevent iatrogenic damage and resulting haemorrhage during TPLO and TTO surgeries. Temporary occlusion of the cranial tibial artery can be achieved through a simple medial approach, proximal to the stifle, in the event of severe haemorrhage associated with TPLO or TTO.

Triple tibial osteotomy for treatment of the canine cranial cruciate ligament-deficient stifle joint. Surgical findings and postoperative complications in 97 stifles.

OBJECTIVE: To report the surgical findings and early post-operative complications of triple tibial osteotomy (TTO) for the treatment of cranial cruciate ligament disruption in dogs. METHODS: Clinical records of 84 dogs (97 stifles) that had TTO procedures were reviewed. Surgical findings and postoperative complications were assessed. A complication was defined as any undesirable outcome resulting from TTO that required further diagnostic investigation or surgical treatment. RESULTS: Mean tibial wedge angle was 13.6 degrees (range 10-20). Incomplete tibial crest osteotomy was achieved in 79% of TTO procedures. Implants were placed in the tibial crest in 67% of stifles. Early postoperative complications occurred in 23% of joints, and included avulsion of the tibial crest (9.1%), fracture at the distal cortical attachment of the tibial crest (6.2%), fibula fracture (4.1%), patellar tendonitis (3.1%), late meniscal injury (3.1%), implant complications (3.1%) and patellar fracture (2.1%). Increased patient age (p = 0.023), increased wedge angle (p = 0.009) and intra-operative fracturing of the cranial tibial cortex (p = 0.017) were significantly associated with postoperative tibial crest avulsion. Implants did not prevent tibial crest avulsion. Increased patient age (p = 0.012) was significantly associated with tibial crest fracture. CLINICAL RELEVANCE: Tibial crest avulsion and fracture are the most common postoperative complications for TTO. Late meniscal injury is uncommon after TTO.

Interaction with stressed mothers affects corticosterone levels in pups after reunion and impairs the response to dexamethasone in adult mice.

BACKGROUND: Early adverse experiences are preeminent factors for the development of affective disorders. In the present study, we analyzed the effects of different postnatal manipulations applied either on the mother or on the offspring in mice. Maternal behavior and adrenocortical activity of both mothers and offspring at the end of postnatal stress and at adulthood were considered. METHODS: From postnatal day (PND) 1 to 14 mice underwent 15min of: (a) brief (15min) pups' exposure to clean bedding (CB: clean bedding), (b) mothers' exposure to the odor of a novel male (SM: stressed mother) or (c) mothers' exposure to a clean cage (CSM: control stressed mother), and (d) standard rearing (N-H: non-handled). The behavior of mouse dams during and after stress sessions was analyzed. Serum corticosterone of mothers and pups at the end of the stress session and 30min after reunion was assessed on PND 14. Moreover, anxiety levels and HPA-axis inhibitory feedback in response to dexamethasone administration were evaluated in adult male offspring. RESULTS: Overall, during the 14 days of treatment CB mothers when reunited with their pups showed higher maternal behavior than other dams. After the last stress (PND 14) SM and CSM maternal corticosterone levels increased as well as those of CB pups. While 30min of mother-infant interaction restored baseline corticosterone levels in SM and CSM mothers and in CB pups, SM and CSM offspring showed a decrease of corticosterone under baseline levels. At adulthood, SM and CSM males did not show the suppressive hormonal response to dexamethasone treatment. Moreover, adult CB and SM male mice displayed decreased anxiety in the open field. CONCLUSIONS: Maternal psychosocial stress during lactation seems to permanently affect the offspring's HPA functioning. These effects may be dissociated from the behavioral response as suggested by the decrease of anxiety in SM and CB adult mice.

Pathophysiological role of TLQP-21: gastrointestinal and metabolic functions.

The present review summarizes recent findings on the metabolic and gastroenteric role of the VGF gene and a peptide derived by post-translational cleavage of the VGF pro-hormone, i.e. TLQP-21. The vgf gene is widely expressed through the central nervous system as well as in the peripheral nervous system, in myenteric plexus ganglia and also in the glandular portion of the stomach. A few VGF derived peptide have been shown to possess biological activity, among them TLQP-21 attracted particular interest following its identification within rat nervous system. In particular, recent studies from our and other groups implicated TLQP-21 in both the modulation of energy homeostasis, body weight regulation and neuroendocrine functions as well as in the central control of gut functions. Overall, findings available point to a role for TLQP-21 in negatively affecting the body energy balance.

Chronic administration of olanzapine affects Behavioral Satiety Sequence and feeding behavior in female mice.

The aim of the study was to assess the effects of chronic olanzapine (Ola) administration on feeding behavior. Although atypical antipsychotics (AAPs) have greatly improved the management of schizophrenia and extrapyramidal symptoms, substantial bodies of literature point out that most of these agents are highly related to a major risk of metabolic drawbacks, leading to dyslipidemia and obesity. Among these compounds, Ola is one of the more weight gain-inducing AAPs. In the present study, we analyzed the Behavioral Satiety Sequence (BSS) in female mice given a palatable diet (wet mash) and chronically administered Ola (0.75, 1.5, 3 mg/kg per os) for 36 days. The results showed that administration of the highest dose of Ola postponed the onset of satiation, as suggested by the rightward shift of the BSS. This effect was confirmed by an increase in the actual food intake by the Ola (3 mg/kg) mice. These results suggest that one of the possible mechanisms involved in AAPinduced weight gain is alteration of the hunger-satiety regulation in female mice. These findings are consistent with the hypothesis that enhanced food intake and diminished central sensitivity to satiation signaling may cooperate in promoting weight gain and metabolic dysregulation in rodents and patients taking antipsychotic medications.

Chronic intracerebroventricular TLQP-21 delivery does not modulate the GH/IGF-1-axis and muscle strength in mice.

OBJECTIVE: Biallelic ablation of VGF determines a dwarf phenotype. VGF precursor protein encodes for different biologically active peptides none of which has been related to growth or muscular abnormalities. Here we present the first attempt to fill this gap. We tested the hypothesis that a recently identified VGF-derived peptide, TLQP-21, shown to centrally modulate metabolic functions, could also modulate growth hormone (GH)-axis and muscle strength. DESIGN: Adult male mice were chronically icv injected with TLQP-21 (15 microg/day for 14 days). Physiological, molecular and behavioral parameters related to the GH/IGF-1-axis were investigated. RESULTS: Except for a reduction in the soleus weight, TLQP-21 did not affect GH/IGF-1-axis mediators, muscle strength and muscle weight. CONCLUSIONS: Results collected exclude a role for TLQP-21 in modulating the GH/IGF1-axis and muscle functions. VGF-derived peptides involved in the dwarf phenotype of VGF-/- mice have to be identified yet.

Parasites of forage fishes in the vicinity of Steller sea lion (Eumetopias jubatus) habitat in Alaska.

Fish serve as intermediate hosts for a number of larval parasites that have the potential of maturing in marine mammals such as Steller sea lions (Eumetopias jubatus). We examined the prevalence of parasites from 229 fish collected between March and July 2002 near two islands used by Steller sea lions in Southeast Alaska and island habitats in the Aleutian Islands. Sea lion populations have remained steady in Southeast Alaska but have been declining over the last 30 yr in the Aleutian Islands. Even though the fish samples near the Southeast Alaska haul-outs were composed of numerous small species of fish and the Aleutian Islands catch was dominated by juveniles of commercially harvested species, the parasite fauna was similar at all locations. Eleven of the 20 parasite taxa identified were in their larval stage in the fish hosts, several of which have been described from mammalian final hosts. Four species of parasite were more prevalent in Southeast Alaska fish samples, and seven parasite species, including several larval forms capable of infecting marine mammals, were more prevalent in fish from the Aleutian Islands. Nevertheless, parasites available to Steller sea lions from common fish prey are not likely to be a major factor in the decline of this marine mammal species.

Psychosocial stress affects energy balance in mice: modulation by social status.

Stress has been associated with changes in eating behaviour and food preferences. Moreover, psychosocial and socio-economical challenges have been related with neuroendocrine-autonomic dysregulation followed by visceral obesity and associated risk factors for disease. In the current study, we provide a model of body weight development, food intake, energy expenditure of subordinate and dominant mice under psychosocial stress either in the presence of a standard diet or of a high palatable diet. When only standard chow was available stressed animals consumed more food in comparison to the control counterpart. Moreover, subordinate mice, at the end of the stress period were heavier in comparison to dominant animals. This last result was due to a decrease in the caloric efficiency of dominant animals in comparison to subordinates. Confirming this, the results of the experiment 2 showed that dominant mice significantly increase their energy expenditure at the end of the chronic psychosocial stress procedure in comparison to subordinate mice, as measured by indirect calorimetry. When a palatable high fat diet was available subordinate animals became heavier in comparison with both dominant and control animals. No differences in the caloric intake were found between groups. Subordinate mice ingested more calories from fat than controls, while dominant animals ingested more calories from carbohydrates. These results suggest that psychosocial stress can be a risk factor for overeating and weight gain in mice. However, social status influences the extent to which an individual keeps up with adverse environment, influencing the vulnerability toward stress related disorders.

Chronic administration of olanzapine induces metabolic and food intake alterations: a mouse model of the atypical antipsychotic-associated adverse effects.

RATIONALE: Most of atypical antipsychotics (AAPs) are highly related to a major risk of metabolic drawbacks leading to dyslipidemia and obesity. OBJECTIVE: To set up a mouse model of the AAP-associated weight gain in mice under the influence of chronic olanzapine regimen. MATERIALS AND METHODS: Female mice were housed in pairs and habituated to spontaneous feeding with a high-palatable diet (10% sucrose wet mash). Firstly, we orally administered olanzapine (0.75, 1.5 and 3 mg/kg), evaluating body weight and periuterine fat mass, as well as insulin, non-esterified fatty acids, triglycerides, and glucose levels. In a second experiment, we assessed the effect of olanzapine on energy expenditure through indirect calorimetry (IC). A third experiment was conducted to investigate the effects of olanzapine on a high fat-high sweet palatable diet (10% sucrose + 30% fat, HF-HS) in mice implanted with subcutaneous osmotic mini-pumps. Locomotor activity was also assessed. RESULTS: In experiment 1, the highest dose of chronically administered olanzapine (3 mg/kg) induced significant weight gain accompanied by augmentation of periuterine fat depots, with no changes in locomotor activity. In experiment 2, chronic administration did not alter energy expenditure, whereas, decreased respiratory quotient (RQ). In experiment 3, subcutaneously infused olanzapine evidenced a dose and time-dependent increase of body weight and HF-HS diet consumed. Notably, serum analyses revealed a hyperinsulinemia together with increased levels of triglycerides and glucose. CONCLUSIONS: In this study, we describe in female mice metabolic alterations matching the metabolic syndrome, thus resembling the clinical situation of schizophrenic patients taking AAPs.

A RelA(p65) Thr505 phospho-site mutation reveals an important mechanism regulating NF-κB-dependent liver regeneration and cancer.

Post-translational modifications of nuclear factor (NF)-κB subunits provide a mechanism to differentially regulate their activity in response to the many stimuli that induce this pathway. However, the physiological significance of these modifications is largely unknown, and it remains unclear if these have a critical role in the normal and pathological functions of NF-κB in vivo. Among these, phosphorylation of the RelA(p65) Thr505 residue has been described as an important regulator of NF-κB activity in cell lines, but its physiological significance was not known. Therefore, to learn more about the role of this pathway in vivo, we generated a knockin mouse with a RelA T505A mutation. Unlike RelA knockout mice, the RelA T505A mice develop normally but exhibit aberrant hepatocyte proliferation following liver partial hepatectomy or damage resulting from carbon tetrachloride (CCl4) treatment. Consistent with these effects, RelA T505A mice exhibit earlier onset of cancer in the N-nitrosodiethylamine model of hepatocellular carcinoma. These data reveal a critical pathway controlling NF-κB function in the liver that acts to suppress the tumour-promoting activities of RelA.

Ultrasonic vocalizations as an index of social memory in female mice.

Ultrasonic vocalization (UV) as a measure of social memory was investigated in female mice. UVs emitted by a resident female in the presence of a same-sex partner were measured during a 3-min, pretest social interaction. In a second 3-min test session, mice were reexposed to the familiar partner or presented with a novel partner. In the first case, there was a decline in UVs emitted by resident mice when the intervals between the 2 sessions were 15, 30, or 60 min. After 24 hr, this effect disappeared. In contrast, with a novel female partner, the number of UVs remained unchanged. Scopolamine (0.05 mg/kg ip) disrupted this memory process: Drug-treated females did not show the expected decrease in UVs when reexposed to the familiar female after 30 min. This study provides behavioral and pharmacological evidence that ultrasonic calls can be used as a measure of social memory in female mice.

Gender differences in depression: an ethological study of nonverbal behavior during interviews.

Previous studies of gender differences in the phenomenology of depression have focused mostly on symptoms as measured by self-report questionnaires or clinician-rated scales. In this study, we examined gender differences in the interpersonal behavior of depressed patients by using ethological techniques which involve direct observation of behavior. The nonverbal behavior of 72 nondepressed volunteers and 68 patients with a DSM-III-R diagnosis of nonpsychotic unipolar depression was videorecorded during clinical interviews and scored according to an ethological scoring system including 37 behavior patterns, mostly facial expressions and hand movements. Both male and female depressed patients showed a global restriction of nonverbal expressiveness reflecting a tendency towards social withdrawal. Nonverbal expression of hostility was the only behavioral category on which depressed patients scored higher than nondepressed volunteers. Even though clinical status exerted marked effects on the ethological profile, depression did not obscure some important differences in the nonverbal behavior of males and females. As a group, depressed women showed more socially interactive behaviors than depressed men. Their modality of interacting included higher levels both of nonverbal hostility and of submissive and affiliative behaviors. These results are discussed in view of clinical data indicating a relationship between gender, style of social interaction and response to antidepressant drugs.

Opioid modulation of sucrose intake in CD-1 mice: effects of gender and housing conditions.

The effects of naltrexone (1 mg/kg, sc.) on consumption of a 5% sucrose solution were observed in nondeprived adult female CD-1 mice and in male mice. Males were either individually housed or were housed in pairs. Naltrexone significantly reduced the consumption of the sucrose in both female and male mice; in the case of the males the administration of naltrexone produced an intake pattern identical to that obtained for a less palatable (1.5%) sucrose solution in control conditions. There was no difference between subordinate and dominant males, neither in sucrose intake nor in the response to the naltrexone treatment. In a second experiment, it was shown that switching from a 5% to a 10% solution was sufficient to overcome naltrexone's suppressant effect in female mice, conversely this was not seen in the males. In general, the data are consistent with the view that opioid antagonists reduce effective palatability of sweet sucrose solutions in mice. There was no evidence that social isolation and stress related to subordination affected male mice's sucrose intake and response to the naltrexone challenge.

A model of social stress in dominant mice: effects on sociosexual behaviour.

The possibility of socially stressing the dominant/aggressive member of a pair of male mice is tested. Male mice (NMRI outbreed strain) were housed in pairs to assess dominant and subordinate roles by agonistic interactions and urine-marking test. Social stress for dominant males consisted in 30 min/day of exposure to their subordinate partner interacting with a female in the adjacent compartment of the cage, for 9 days. Results showed that dominance status was maintained. Behavioural observations indicated that neither the subordinates nor the dominant males habituated to this experimental procedure. At the end of the chronic stress, dominant animals were given the opportunity to interact for 30 min with a female in their compartment. Results indicated that stressed dominants showed impairment in their sexual behaviour and were more oriented towards the physical environment in comparison with control dominants. The behavioural response to apomorphine (0.25 mg/kg) indicated an alteration of the dopaminergic functioning in socially stressed dominant mice. This study suggests that the characteristics of the stressor and the effects of the chronic social stress could be different, according to male social status.

Age specificity of the relationship between serum cholesterol and mood in obese women.

Despite increasing evidence of an association between lower cholesterol levels and negative mood, no study has specifically investigated this relationship in obese people, a population at high risk for both dyslipidaemia and depression. Data on serum cholesterol and mood were collected in a group of 73 healthy women, aged 16 to 76 years, with different degrees of obesity and widely varying total cholesterol concentrations. Mood was assessed using three self-rated scales: the Toronto Alexithymia Scale (TAS-20), the State-Trait Anger Scale (STAS), and the Beck Depression Inventory (BDI). The association between lower total cholesterol levels and negative mood was age-dependent. No significant association was found in the younger age group (<50 years). In contrast, in the subgroup of older women, serum cholesterol was negatively and significantly correlated with the TAS-20 and the STAS. The negative correlation between serum cholesterol and the BDI was nearly statistically significant. Restricting analysis to the subjects in the highest quartile of the age distribution (>60 years) yielded stronger correlations between cholesterol and mood. In this sample of obese women, the relationship between lower cholesterol levels and negative mood was age-specific and limited to the older age group. The results of this study suggest that preventive programs or drug treatments for reducing cholesterol levels in elderly obese women should include a careful evaluation of mood state.

Definitions of 'healthy' eating: a pan-EU survey of consumer attitudes to food, nutrition and health.

OBJECTIVE: To describe the perceptions of a healthy diet across Europe and to explore the socio-cultural factors that influence these perceptions. DESIGN: A cross-sectional study in which quota-controlled, nationally-representative samples of approximately 1000 adults from each country completed a face-to-face interview-assisted questionnaire. SETTING: The survey was conducted between October 1995 and February 1996 in the 15 member states of the European Union. SUBJECTS: 14331 subjects (aged 15 y upwards) completed the questionnaire. Data were weighted by population size for each country and by sex, age and regional distribution within each member state. RESULTS: Responses were grouped into broad categories; overall 80% (specific country rates varied from 67-91%) of respondents mentioned either more fruit and vegetables or less fat, fatty foods, or a low fat diet, or balance and variety. The effects of age, gender and level of education were also explored: educational level appeared to have the strongest influence on perceptions of a healthy diet. Respondents who mentioned the family as a key influence on food choice, were more likely to mention eating more fruit and vegetables as part of a healthy diet. Respondents who stated that they did not have any source of information about diet were less likely to mention balance and variety or less fat or more vegetables. CONCLUSIONS: The results of the present study suggest that many people defined healthy eating in a way which would suggest that the healthy dietary guidelines are having some impact. The results also show, however, that there may be specific groups who are missed by current national campaigns, and that any European wide campaigns to change attitudes about healthy eating need to consider the baseline perception of healthy eating reported here.

Difficulties in trying to eat healthier: descriptive analysis of perceived barriers for healthy eating.

OBJECTIVE: To determine the factors which are perceived to be important barriers to healthy eating among European adults. DESIGN: A cross sectional study in which quota-controlled, nationally-representative samples of approximately 1000 adults from each country completed a face-to-face interview-assisted questionnaire. SETTING: The survey was conducted between October 1995 and February 1996 in the 15 member states of the European Union. SUBJECTS: 14,331 subjects (aged 15 y upwards) completed the questionnaire. Data were weighted by population size for each country and by sex, age and regional distribution within each member state. RESULTS: The study demonstrates a great variability in the perceived barriers to healthy eating between different EU countries. Lack of time was the most frequently mentioned difficulty among EU subjects for not following nutritional advice (24% of total EU sample). This barrier was frequently reported by the younger and the higher education people. Other frequently reported barriers were giving up favourite foods (23%) and willpower (18%). Thus healthy diets do not appear to be viewed as an easy or attractive alternative to current diets. There was wide geographical variation in the number of subjects mentioning price as an important barrier to healthy eating (15% in overall EU sample) ranging from less than 10% in Germany and Italy to 23% in the UK and 24% in Luxembourg.

Kinship and familiarity as factors affecting social transfer of food preferences in adult Mongolian gerbils (Meriones unguiculatus).

Experiments were carried out with Mongolian gerbils (Meriones unguiculatus) to assess whether a socially mediated acquisition of diet selection exists in this species. Results showed that a gerbil was influenced in its diet choices by information extracted during a brief period of interaction with a familiar conspecific that had recently eaten a novel food. Data revealed that the acquisition of a food preference from a conspecific depends on the existence of a social bond between the interacting gerbils. Either genetic relatedness (being brother or sister raised in different litters) or familiarity (being bred in the same litter or being member of a reproductive pair) is necessary for the transfer of information. Unfamiliar and unrelated observer gerbils did not selectively choose their demonstrator's food.