Detection of 'Candidatus Neoehrlichia mikurensis' and other Anaplasmataceae and Rickettsiaceae in Canidae in Switzerland and Mediterranean countries

INTRODUCTION

'Candidatus Neoehrlichia mikurensis' is an emerging tick-borne zoonotic agent that primarily affects immunocompromised human patients. Dogs and foxes are frequently exposed to ticks, and both species are in close proximity to humans. This is the first study to systematically investigate the occurrence of 'Candidatus Neoehrlichia mikurensis' in Canidae in Europa. We analyzed 1'739 blood samples from dogs in Switzerland, Italy, Spain and Portugal and 162 blood samples from free-ranging red foxes (Vulpes vulpes) in Switzerland. All samples were tested using a previously described multiplex real-time PCR for the Anaplasmataceae family, the 'Candidatus Neoehrlichia' genus and the 'Candidatus Neoehrlichia mikurensis' species. All Anaplasmataceae positive samples were subsequently tested using specific real-time PCRs for Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis and Rickettsia helvetica. Among the tested animals, one dog from Zurich tested positive for 'Candidatus Neoehrlichia mikurensis'. The 12-year old West Highland white terrier had been splenectomized 3 months prior to the blood collection and presented with polyuria/polydipsia. Fanconi syndrome was diagnosed based on glucosuria with normoglycemia and hyperaminoaciduria. A. platys and E. canis were detected in 14/249 dogs from Sicily and Portugal; two of the dogs were coinfected with both agents. Four Swiss foxes tested positive for A. phagocytophilium. R. helvetica was detected for the first time in a red fox. In conclusion, 'Candidatus Neoehrlichia mikurensis' infection should be considered in sick dogs, particularly when immunocompromised. The pathogen seems not to be widespread in Canidae in the investigated countries. Conversely, other Anaplasmataceae were more readily detected in dogs and foxes.

Aβ Induces Excitotoxicity Mediated by APC/C-Cdh1 Depletion That Can Be Prevented by Glutaminase Inhibition Promoting Neuronal Survival

The E3 ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C) is activated by the fizzy-related protein homolog/CDC20-like protein 1 (cdh1) in post-mitotic neurons. Growing evidence suggests that dysregulation of APC/C-Cdh1 is involved in neurodegenerative diseases. Here we show in neurons that oligomers of amyloid beta (Aβ), a peptide related to Alzheimer’s disease, cause proteasome-dependent degradation of cdh1. This leads to a subsequent increase in glutaminase (a degradation target of APC/C-Cdh1), which causes an elevation of glutamate levels and further intraneuronal Ca²⁺ dysregulation, resulting in neuronal apoptosis. Glutaminase inhibition prevents glutamate excitotoxicity and apoptosis in Aβ treated neurons. Furthermore, glutamate also decreases cdh1 and leads to accumulation of glutaminase, suggesting that there may be a positive feedback loop of cdh1 inactivation. We confirmed the main findings in vivo using microinjection of either Aβ or glutamate in the CA1 region of the rat hippocampus. We show here for the first time in vivo that both Aβ and glutamate cause nuclear exclusion of cdh1 and an increase in glutaminase. These results show that maintaining normal APC/C-Cdh1 activity may be a useful target in Alzheimer’s disease treatment.

Molecular mechanisms linking amyloid β toxicity and Tau hyperphosphorylation in Alzheimer׳s disease

Neurofibrillary tangles (aggregates of cytoskeletal Tau protein) and senile plaques (aggregates mainly formed by amyloid β peptide) are two landmark lesions in Alzheimer׳s disease. Some researchers have proposed tangles, whereas others have proposed plaques, as primary lesions. For a long time, these were thought of as independent mechanisms. However, experimental evidence suggests that both lesions are intimately related. We review here some molecular pathways linking amyloid β and Tau toxicities involving, among others, glycogen synthase kinase 3β, p38, Pin1, cyclin-dependent kinase 5, and regulator of calcineurin 1. Understanding amyloid β and Tau toxicities as part of a common pathophysiological mechanism may help to find molecular targets to prevent or even treat the disease.

Aβ and tau toxicities in Alzheimer's are linked via oxidative stress-induced p38 activation: protective role of vitamin E

Oxidative stress is a hallmark of Alzheimer's disease (AD). We propose that rather than causing damage because of the action of free radicals, oxidative stress deranges signaling pathways leading to tau hyperphosphorylation, a hallmark of the disease. Indeed, incubation of neurons in culture with 5 µM beta-amyloid peptide (Aβ) causes an activation of p38 MAPK (p38) that leads to tau hyperphosphorylation. Inhibition of p38 prevents Aβ-induced tau phosphorylation. Aβ-induced effects are prevented when neurons are co-incubated with trolox (the water-soluble analog of vitamin E). We have confirmed these results in vivo, in APP/PS1 double transgenic mice of AD. We have found that APP/PS1 transgenic mice exhibit a high level of P-p38 in the hippocampus but not in cortex and this is prevented by feeding animals with a diet supplemented with vitamin E. Our results underpin the role of oxidative stress in the altered cell signaling in AD pathology and suggest that antioxidant prevention may be useful in AD therapeutics.

Superficial necrolytic dermatitis in a dog with an insulin-producing pancreatic islet cell carcinoma

A 10-year-old dog presented with convulsive crisis and symmetrical hyperkeratotic cutaneous lesions affecting the abdomen, inguinal area, eyelids, muzzles, both pinnae, and all the paw pads. Hypoglycemia and hyperinsulinemia were the main biochemical findings. A mass 2 cm in diameter was detected within the left pancreatic lobe by ultrasonography. It was surgically removed and histologically and immunohistochemically diagnosed as an insulin-producing pancreatic islet cell carcinoma. The animal was eventually euthanized due to lack of clinical improvement. At necropsy, metastatic nodules were observed in the pancreatic lymph nodes and liver. Histopathological findings of cutaneous lesions were highly suggestive of superficial necrolytic dermatitis and were interpreted as a paraneoplastic syndrome derived from the islet cell carcinoma. To the authors' knowledge, this is the first report of superficial necrolytic dermatitis associated with an insulin-producing pancreatic neuroendocrine carcinoma in dogs.

Antioxidant pathways in Alzheimer's disease: possibilities of intervention

Alzheimer's disease (AD) is closely related to the occurrence of oxidative stress. It was claimed that all pathophysiological mechanisms involved in the onset and progression of AD are related to oxidative stress. Thus, it is important to evaluate if there is oxidative stress as well as the mechanism by which this happens in AD patients as well as in animal models of AD. Extracellular plaques of amyloid b peptides (Aβ), a hallmark of the disease, have been postulated to be more protective than damaging in terms of oxidative stress because they may be chemical sinks in which heavy metals are placed. More than a decade ago we reasoned that damage due to Ab might be caused not by extracellular, but rather intracellular Ab peptide interacting with normal cell metabolism. Ab binds to mitochondrial membranes, interacts with heme and thus interferes with the normal electron flow through the respiratory chain. This results in a faulty mitochondrial energy metabolism and in an increased production of reactive oxygen species (ROS). The low mitochondrial energy metabolism may important to explain the hypo metabolism observed in AD patients in vivo (measured by positron emission tomography) and in isolated neurons incubated in the presence of Ab peptide. The increased ROS production results in oxidative stress. The occurrence of such stress provides the basis for a putative treatment of AD with antioxidants. Major efforts have been made to determine whether antioxidant supplementation could be a means of preventing, or even treating AD, but this idea is far from being well- established. We found that even though there is oxidative stress in AD, the administration of antioxidant vitamins, particularly vitamin E, is not effective in preventing the progression of the disease in all patients. We termed this the vitamin E paradox in AD. The paradox is the fact that for some patients, vitamin E could even be detrimental whereas for others vitamin E treatment partially prevents the loss memory associated with the progression of the disease. It is clear, however, that increasing the intake of fruits and vegetables rich in antioxidant vitamins, prevents or retards the onset of AD. Thus, the issue of whether antioxidant treatment is of use in AD is not settled and more research is warranted to clarify this point.

Neoadjuvant chemoradiotherapy and surgery as treatment for oral maxillary squamous cell carcinoma in a dog

A gingival maxillary squamous cell carcinoma was diagnosed in a 12-year-old male Yorkshire Terrier. After a complete diagnostic work-up, including a computed tomography scan, the tumour was staged as T3bN1aM0 and considered non-resectable at presentation. The combination of neoadjuvant megavoltage radiotherapy and neoadjuvant and adjuvant chemotherapy with carboplatin and doxorubicin decreased the size of the tumour, allowing for surgery. The dog was free from local disease for 421 days after which it was euthanased at the owners' request.

[Inflammatory myxohyaline tumor of the distal extremities]

Inflammatory myxohyaline tumor of the distal extremities is an extremely rare low-grade sarcoma with a tendency to produce local recurrence after surgical excision, but with a low metastatic potential. We present the case of a 49-year-old woman with a slow-growing asymptomatic tumor on the right pretibial region that was initially considered to be a lipoma. Histopathology revealed the presence of a polymorphic inflammatory infiltrate within a myxoid and hyaline matrix. Interspersed between the inflammatory cells were 3 different populations of neoplastic cells: atypical spindle-shaped cells; bizarre epithelioid cells, some of which were multinucleated and resembled the virocytes or Reed-Sternberg cells; and cells with abundant, vacuolated cytoplasm, similar to lipoblasts. These clinical-pathologic findings led to a diagnosis of inflammatory myxohyaline tumor of the distal extremities. Although the tumor was excised with wide surgical margins, local recurrence developed after 3 months and was treated with re-excision and radiotherapy.

Neutrophilic dermatosis resembling pyoderma gangrenosum in a dog with polyarthritis

This report describes a case of neutrophilic dermatosis in a dog, with a number of clinical and pathological similarities to human pyoderma gangrenosum. A seven-year-old, female German shepherd dog with a history of non-erosive idiopathic polyarthritis was presented with severe facial swelling, bilateral erosivoulcerative lesions on the muzzle and multiple, eroded, dermal-subcutaneous nodules on the cranial trunk. Histopathological examination of skin biopsies revealed a necrotising neutrophilic dermatitis. No infectious agents could be detected using specific stains, immunohistochemistry, serology and bacterial aerobic, anaerobic or fungal cultures. A sterile neutrophilic dermatosis resembling human pyoderma gangrenosum was presumptively diagnosed, and the patient showed an excellent response to treatment with prednisone and ciclosporin.

Characterization of a gene similar to BIK1 in the yeast Kluyveromyces lactis

In Saccharomyces cerevisiae, Bik1p is a microtubule plus-end-tracking protein that plays several roles in mitosis and ploidy. KlBik1p (from Kluyveromyces lactis) maintains the same structural-domain organization as does S. cerevisiae Bik1p. As part of its characterization, we constructed a stable klbik1 mutant which is sensitive to benomyl only at 14 degrees C and has a higher frequency of crescent-shaped nuclei than S. cerevisiae bik1 mutants. This phenotype is partially rescued by S. cerevisiae BIK1. Other phenotypes associated with bik1 are not present in the K. lactis mutant. By fusion to GFP we were able to show the functionality of the KlBik1p CAP-Gly domain and found that the fusion protein changes its cellular location during the cell cycle.

Free radicals in exhaustive physical exercise: mechanism of production, and protection by antioxidants

Moderate exercise is a healthy practice. However, exhaustive exercise generates free radicals. This can be evidenced by increases in lipid peroxidation, glutathione oxidation, and oxidative protein damage. It is well known that activity of cytosolic enzymes in blood plasma is increased after exhaustive exercise. This may be taken as a sign of damage to muscle cells. The degree of oxidative stress and of muscle damage does not depend on the absolute intensity of exercise but on the degree of exhaustion of the person who performs exercise. Training partially prevents free radical-formation in exhaustive exercise. Treatment with antioxidants such as vitamins C or E protects in part against free radical-mediated damage in exercise. Xanthine oxidase is involved in free-radical formation in exercise in humans and inhibition of this enzyme with allopurinol decreases oxidative stress and muscle damage associated with exhaustive exercise. Knowledge of the mechanism of free-radical formation in exercise is important because it will be useful to prevent oxidative stress and damage associated with exhaustive physical activity.

Vitamin A deficiency causes oxidative damage to liver mitochondria in rats

Mitochondrial damage in rat liver induced by chronic vitamin A-deficiency was studied using three different groups of rats: (i) control rats, (ii) rats fed a vitamin A-free diet until 50 d after birth and (iii) vitamin A-deficient rats re-fed a control diet for 30 d. No statistical difference in body weight and food intake was found between control and vitamin A-deficient rats. Liver GSH concentration was similar in both groups. However, in vitamin A-deficient rats, the mitochondrial GSH/GSSG ratio was significantly lower and the levels of malondialdehyde (MDA) and 8-oxo-7, 8-dihydro-2'-deoxyguanosine (oxo8dG) were higher when compared to control rats. These values were partially restored in re-fed rats. The mitochondrial membrane potential of vitamin A-deficient rats was significantly lower than in control rats and returned to normal levels in restored vitamin A rats. Two populations of mitochondria were found in vitamin A-deficient rats according to the composition of membrane lipids. One population showed a similar pattern to the control mitochondria and the second population had a higher membrane lipid content. This report emphasizes the protective role of vitamin A in liver mitochondria under physiological circumstances.

Efficacy and safety of lesopitron in outpatients with generalized anxiety disorder

OBJECTIVE

To compare the relative efficacy and safety of lesopitron 4-80 mg/d versus lorazepam 2-4 mg/d and placebo in a subgroup of patients with anxiety history taken from a larger study of patients with a primary diagnosis of generalized anxiety disorder (GAD).

DESIGN

Six-week, randomized, double-blind, parallel, placebo and lorazepam-controlled, Phase II, single-center, outpatient study.

SETTING

Outpatient clinic.

PATIENTS

One hundred sixty-one patients with GAD were randomized in the main study; 68 with a documented history of GAD or anxiety disorder not otherwise specified were included in the subgroup.

METHODS

After a one-week placebo lead-in, patients were randomized to receive placebo, lesopitron, or lorazepam twice daily for six weeks, followed by a one-week taper period. Efficacy was assessed using the Hamilton Rating Scale for Anxiety (HAM-A) and the Clinical Global Impressions scale. Safety was assessed through physical examinations, monitoring of vital signs, 12-lead electrocardiograms, laboratory analyses, and adverse event monitoring.

RESULTS

An overall mean improvement in the HAM-A total score between baseline and end point for all three treatment groups was seen, with mean changes of 3.4 (95% CI 2.0 to 4.8), 6.1 (95% CI 4.1 to 8.1), and 6.1 (95% CI 4.6 to 7.6) for the placebo, lesopitron, and lorazepam groups, respectively (omnibus p = 0.044, uncorrected). Positive treatment effects were also observed in the subgroup population on several other measures and suggest that additional therapeutic trials may be warranted. Future trials could be stratified on the basis of referral status (symptomatic volunteer vs. clinical patient with preexisting illness) or previous exposure to anxiolytics, and use a fixed-dose rather than flexible-fixed-dose design.

CONCLUSIONS

The subgroup analysis represents a comparison of treatment outcome in GAD patients presenting with a history of previous episodes of GAD or anxiety disorder not otherwise specified compared with those who were experiencing their first episode of GAD and reported no anxiety history. Although the overall study analysis was equivocal, for the approximately 40% of patients with recurrent anxiety disorder, beneficial effects for both lesopitron and lorazepam are suggested.

Late onset administration of oral antioxidants prevents age-related loss of motor co-ordination and brain mitochondrial DNA damage

We have studied the effect of aging on brain glutathione redox ratio, on brain mitochondrial DNA damage and on motor co-ordination in mice and the possible protective role of late onset administration of sulphur-containing antioxidants. Glutathione redox ratios change to a more oxidized state in whole brain with aging but the changes are much more pronounced when this ratio is measured in brain mitochondria. The levels of 8-oxo-7,8-dihydro-2 '-deoxyguanosine in mitochondrial DNA are much higher in the brain of old animals than in those of young ones. Late onset oral administration of sulphur-containing antioxidants partially prevents oxidation of mitochondrial glutathione and DNA. There is an inverse relationship between age-associated oxidative damage to mitochondrial DNA and motor co-ordination in old mice.

Isolation and characterization of Rhizobium etli mutants altered in degradation of asparagine

Rhizobium etli mutants unable to grow on asparagine as the nitrogen and carbon source were isolated. Two kinds of mutants were obtained: AHZ1, with very low levels of aspartase activity, and AHZ7, with low levels of asparaginase and very low levels of aspartase compared to the wild-type strain. R. etli had two asparaginases differentiated by their thermostabilities, electrophoretic mobilities, and modes of regulation. The AHZ mutants nodulated as did the wild-type strain and had nitrogenase levels similar to that of the wild-type strain.

Double-blind, randomized clinical trial on the effect of interferon-beta in the treatment of condylomata acuminata

A randomized, double-blind, placebo-controlled trial was conducted to assess interferon-beta efficacy and safety in the treatment of anogenital condylomatous lesions. One hundred patients received a daily intramuscular injection of either interferon-beta (IFN-beta) (2 MIU/day) or placebo for 10 days. Of 94 evaluable patients, the complete response rate observed 8 weeks after treatment was significantly higher in the group receiving IFN-beta, as compared to the placebo-treated group (51% vs 28.9%, P < 0.05). After one year, 24 patients (100%) out of 24 complete responders to IFN-beta who attended for follow-up remained free of lesions. Twelve of 13 patients with complete response to placebo (92.3%) remained free of lesions after one year. Side effects were mild and no significant analytical changes were observed. In conclusion, interferon-beta is an effective and safe treatment for long-term eradication of anogenital condylomatous lesions.

[A prognostic multifactorial study of sepsis in an internal medicine service]

All cases of sepsis attended at the Service of Internal Medicine from 1985 to 1989, both inclusive, were retrospectively analyzed by the statistical study of several clinical, epidemiological, bacteriological and laboratory factors. The parameters acting as prognosis factors were analyzed using Cox's method of logistic regression, in order to obtain more reliable information on the multifactorial spectrum determining "death due to sepsis". The unifactorial analysis (UFA) suggested that the following factors were associated to an statistically significant increase in the mortality due to sepsis: age above 70; male sex; presence of shock upon hospitalization; nosocomial etiology; high levels of urea, creatinine and LDH; proteinuria; family of the causal germ (gram-positive coccus) and underlying pathology. The relative risks (RR) or "odd ratios" of creatinine and LDH were, respectively, 2.8 and 2.9 in the UFA; 3 and 3.3 in the multivariant analysis (MVA). In the older patients developing sepsis within their communities, RR were respectively 2.7 and 1.98 in the UFA and 1.1 and 2.7 in the MFA. The results of the univariant and multivariant analysis showing the relative risk (odd ratio) associated to each of these variables with statistical significance, demonstrate that the mortality rate due to sepsis increases with age, nosocomial etiology and elevation of creatinine and lactodehydrogenase (LDH) levels. We stress the great importance of the LDH as a prognostic factor of sepsis.

Bowenoid papulosis: clinical and histological study of eight cases

Eight cases of bowenoid papulosis are reported. The clinical diagnoses were confirmed by histology. In one case an immunoperoxidase method showed the presence of papillomavirus antigen in the nucleus of the most superficial epidermal cells. We consider bowenoid papulosis to be a condition with specific features that distinguish it clinically and histologically from carcinoma in situ and condylomata acuminata.