Dementia in Latin America: Paving the way toward a regional action plan

Across Latin American and Caribbean countries (LACs), the fight against dementia faces pressing challenges, such as heterogeneity, diversity, political instability, and socioeconomic disparities. These can be addressed more effectively in a collaborative setting that fosters open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking, and translational research) and align them to current global strategies to translate regional knowledge into transformative actions. Then we characterize key sources of complexity (genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions), map them to the above challenges, and provide the basic mosaics of knowledge toward a KtAF. Finally, we describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF.

Risk Factors for Incident Dementia Among Older Cubans

Introduction: Little is known about risk factors of dementia in Latin American countries. We aimed to identify socio–demographic, health and lifestyle risk factors of incident dementia in Cuban older adults.

Methods: Data were from 1,846 participants in the Cuban cohort of the 10/66 Dementia Research Group. Participants completed questionnaires, health examinations, and cognitive tests at baseline (2003–2006) and 4.5 years later (2007–2010). Associations between risk factors (baseline) and incident dementia (follow-up) were examined using logistic regression.

Results: Just over 9% of participants developed dementia. Overall, older age and low physical activity were associated with incident dementia. In those 65–74 years of age, depression, stroke and low physical activity were associated with incident dementia. In those ≥75 years of age, low physical activity, never eating fish, and smoking were associated with incident dementia.

Conclusions: Modifiable lifestyle factors play an important role in developing dementia in Cuban older adults. This knowledge opens up opportunities for preventive strategies.

Neurological signs as early determinants of dementia and predictors of mortality among older adults in Latin America: a 10/66 study using the NEUROEX assessment

Background

Neurodegenerative processes in the elderly damage the brain, leading to progressive, incapacitating cognitive, behavioral, and motor dysfunctions which culminate in dementia. Fully manifest dementia is likely to be preceded by the presence of neurological signs, which could serve as early determinants of dementia and predictors of mortality. The aims of this study were to assess the construct validity of a neurological battery assessed among older adults living in Latin America, and to test the association of groups of neurological signs with dementia cross-sectionally, and mortality longitudinally.

Methods

The 10/66 Dementia Research Group collected information on neurological symptoms via the NEUROEX assessment in population based surveys of older adults living in low and middle-income countries. Data from 10,856 adults participating in the baseline assessment of the 10/66 study and living in Cuba, Dominican Republic, Peru, Venezuela and Mexico were analysed. Exploratory and confirmatory analysis were used to explore dimensionality of neurological symptoms. Poisson regression analyses were used to link groups of neurological signs with dementia at baseline. Cox hazard regression models were used to explore the predictive validity of neurological signs with mortality at follow up.

Results

Exploratory and confirmatory factor analyses revealed four dimensions of neurological signs, which are associated with lesions of specific brain regions. The identified factors showed consistency with groups of neurological signs such as frontal, cerebellar, extrapyramidal, and more generalized gait disturbance signs. Regression analyses revealed that all groups of neurological signs were positively associated with dementia at baseline and predicted mortality at follow up.

Conclusions

Our findings support the construct and predictive validity of the NEUROEX assessment, linking neurological and gait impairments with dementia at baseline, and with mortality at follow up among older adults living in five Latin American countries.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1167-4) contains supplementary material, which is available to authorized users.

[Experience of implementing the ISO 9001:2015 standard for the accreditation of a paediatric hospital emergency department]

OBJECTIVE

The aim of this paper was to describe the process for accrediting a paediatric hospital emergency department to ISO 9001:2015 standards. The implementation process began in February 2015 and lasted 18months.

MATERIAL AND METHODS

The project started with the decision by the Head of Department to improve service quality. A Quality Committee was established with representation of the medical, nursing and administrative staff. Training sessions were held on quality management systems and ISO standards for employees. A meeting took place among members of the Emergency Department to define the main processes, and 14 were identified, documented and included in the processes map. Workgroups were then created to review and redesign the medical and nurse protocols.

RESULTS

Thirty-five medical and fifteen nursing protocols were incorporated into the management system, and quality indicators were established that allowed the whole process to be monitored. A risk register was created to record identified risks, their severity, likelihood of occurrence, and actions taken to prevent or reduce those risks. The Emergency Department underwent an external audit during June 2016, and was certified to the requirements demanded by the international ISO 9001:2015 standard.

CONCLUSIONS

The conclusion is that implementation of a quality management system on ISO and its certification is completely achievable, and has contributed to better patient management.

Retrospective--systematic study and quantitative analysis of cellular proliferation and apoptosis in normal, hyperplastic and neoplastic perianal glands in dogs

Neoplasms in the perianal region are frequently diagnosed in dogs. The aetiology is unknown, and most of them are benign. In this study, 240 neoplasms of the perianal glands of dogs were retrieved from the Department of Pathology archives of the Faculty of Veterinary Medicine and Zootechny of University of São Paulo (FMVZ/USP), from 1984 to 2004. All 240 cases were re-examined by two pathologists. Nine cases (4%) were diagnosed as hyperplasia, 49 (20%) as group I adenoma, 81 (34%) were classified as moderately differentiated adenomas of the group II, 46 (19%) were poorly differentiated adenomas of group II, 48 (20%) were carcinoma of the group III according to the classification proposed by Berrocal, and 7 (13%) were other kind of tumours. Males over 8 years of age were predominantly affected. Cell proliferation was quantified by counting proliferating cell nuclear antigen (PCNA) positive nuclei, and apoptosis was quantified by counting fluorescent eosin-stained apoptotic corpuscles (AC) in normal tissue, hyperplasia and in different histologic types of neoplasia of these glands. A parallel pattern of increase in both parameters (cell proliferation and apoptosis) was obtained. The net growth index (NGI), represents how much a cell population is proliferating or dying and was achieved by dividing the mean PCNA count in 1000 cells by the mean AC stain count in 1000 cells. NGI was different between hyperplasia and neoplasia; group I adenomas have a much higher potential of growth, and NGI decreases from benign towards malignant lesions. These results show up the importance of studying cell proliferation and apoptosis to understand the carcinogenesis of dog perianal gland.

Effect of Senna occidentalis Seeds on Immunity in Broiler Chickens

This study investigated possible immunotoxic effects of Senna occidentalis (So) seeds incorporated in broiler chicken rations at different concentrations (0.0%, 0.25%, 0.50% and 0.75%), for 28 or 42 days. We evaluated innate immune function (macrophage activities of spreading, phagocytosis, peroxide and nitric oxide production) and acquired immune function (humoral and cellular immune responses), as well as lymphoid organ weights and pathology. There was enhanced macrophage activity, as hydrogen peroxide production increased (P < 0.05) in cells of birds given 0.75%So, but there were no other pro-inflammatory effects. Birds receiving 0.75% of So in ration for 42 days gained less weight (P < 0.01), and showed a decrease in relative weight of the bursa of Fabricius (P < 0.05) and spleen (P < 0.01). In addition, morphological changes were also noted in these lymphoid organs, with depletion of lymphoid cells on the spleen and bursa of Fabricius, resulting in lower relative weight of both lymphoid organs. No impairment of humoral immune response against Newcastle disease and in cellular immune response after a phytohaemagglutinin challenge was found. It is probable that mitochondrial damage and related apoptosis may be responsible for the enhanced peroxide production and the reduced relative weight of the bursa of Fabricius and spleen.

Histopathological changes during experimental infections of calves withCooperia punctata

Eleven male two-month-old Holstein calves were used to determine the pathological changes induced by aCooperia punctatainfection. After weaning, ten calves received a single oral dose of 45,000C. punctatainfective larvae. One calf remained as a non-infected control. Groups of two calves were killed on days 7, 14, 21, 28 and 35 post-infection (p.i.) for determination of worm burdens and histopathological evaluation. The small intestine was sub-divided into three sections of approximately equal length, and representative samples of mucosa were fixed in 10% formalin, cut, and stained with haematoxylin-eosin. Samples of intestinal contents and mucosal digests were taken and fixed in 10% formalin for an estimation of total worm burdens. An increase in the number of adult parasites and a decrease in the number of larvae were observed with time (P<0.001). A higher concentration of worms was found in the first segment of the small intestine during the five weeks of observation. Histology showed larvae in the intestinal mucosa on day 7 p.i., with a discrete increase in the cellular response. Adult worms and a marked cellular infiltrate with eosinophils and neutrophils were present on day 21 p.i., and these persisted until day 35 p.i. Microcysts resulting from worm destruction were observed from day 21 p.i.

Effects of Long-term Cyanide Ingestion by Pigs

Animal performance and health status are adversely affected by long-term cyanide ingestion; however, the effects of cyanide ingestion by pigs have not been fully determined. The aim of the present study was to determine the effects of prolonged exposure to different doses of potassium cyanide (KCN) in growing-finishing swine. Twenty-four pigs, 45 days of age, were divided into four equal groups and treated with different doses of KCN: 0, 2.0, 4.0 or 6.0 mg per kg body weight per day for 70 consecutive days. The results showed a significant alteration in thiocyanate, creatinine and urea levels and in alanine aminotransferase activity of swine dosed with 4.0 and 6.0 mg/kg/KCN. Thyroid weight was significantly increased in those pigs from 4.0 mg/kg KCN group, but no change in cholesterol, triiodothyronine or thyroline levels were observed. Body and carcase weights, body weight gain, and bacon thickness were not affected by KCN treatment. The histopathological study revealed increased numbers of vacuoles in the colloid of thyroid follicles, degeneration of cerebellar white matter and Purkinje cells, degeneration of renal tubular epithelial cells, caryolysis and pyknosis in hepatocytes, and disturbance of the normal lobular architecture of the liver in all treated pigs. Thus, long-term administration of KCN to swine affects several tissues and could adversely affect animal production.

Effects of prolonged oral administration of aflatoxin B1 and fumonisin B1 in broiler chickens

The effects of prolonged oral administration of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) mycotoxins were evaluated in broiler chickens from 21 to 42 d of age. A total of 192 birds were housed in experimental batteries and assigned to 32 cages, 6 birds per cage. The following treatments were applied: 1) 0 mycotoxins (control), 2) 10 mg of FB1, 3) 50 microg of AFB1, 4) 50 microg of AFB1 + 10 mg of FB1, 5) 350 microg of AFB1, 6) 350 microg of AFB1 + 10 mg of FB1, 7) 2,450 microg of AFB1, 8) 2,450 microg of AFB1 + 10 mg of FB1/kg of feed. Each treatment consisted of 4 replicates of 6 birds each. At the end of the trial, blood samples from 12 birds per treatment were collected, and the birds were necropsied. Compared with controls, the percentage of heterophils was lower (P < 0.05) in birds from groups receiving 50 microg of AFB1/kg + 10 mg of FB1/ kg and 2450 microg of AFB1/kg alone or in combination with FB1. A higher percentage of lymphocytes (P < 0.05) was observed in birds fed 50 microg of AFB1/kg + 10 mg of FB1/ kg, 350 microg of AFB1/kg, and 2,450 microg of AFB1/kg. A decrease in plasma albumin was observed only in birds fed 2,450 microg of AFB1/kg + 10 mg of FB1/kg. The liver of AFB1-treated birds had focal areas of necrosis and inflammatory infiltrates. In birds fed rations containing only 10 mg of FB1/kg, bile duct hyperplasia with fibrosis and a mononuclear infiltrate accompanied by trabecular derangement were observed. In contrast, in treatments in which FB1 was administered in combination, hepatic vacuolar degeneration was observed, and renal tissue presented corpuscles with increased cellular agglomeration, characterizing glomerulonephritis, and a clearly visible tubular epithelium with areas of degeneration and necrosis. The FB1 residues were detected in liver and in excreta of all FB1-treated groups, at levels that ranged from 0.013 to 0.051 mg/kg and from 1.19 to 2.79 mg/kg, respectively. Results indicated that FB1 and AFB1, singly or in combination at the levels evaluated, do not change markedly the hematological and serological parameters of broiler chickens, but may cause relevant lesions in liver and in kidneys.

Histopathologic patterns of nephropathy in naturally acquired canine visceral leishmaniasis

Although the nephropathy of visceral leishmaniasis (VL) is known both in humans and dogs, histopathologic alterations have not been thoroughly studied. We examined renal alterations in 55 dogs with naturally acquired VL compared with five noninfected dogs from an endemic area in northeastern Brazil. Glomerulonephritis was found in 55 dogs, interstitial alterations in 53 dogs, and tubular changes in 43 dogs with VL. The glomerular alterations found were minor glomerular abnormalities (n = 8, 14.5%), focal segmental glomerulosclerosis (n = 10, 18.2%), mesangial proliferative glomerulonephritis (n = 17, 32.7%), membranoproliferative glomerulonephritis, (n = 18, 30.9%), crescentic glomerulonephritis (n = 1, 1.8%), and chronic glomerulonephritis (n = 1, 1.8%). Morphometric and ultrastructural studies complemented the analysis. The five control animals exhibited no glomerular alterations. The glomerular lesions were related to functional alterations. Considering that the alterations of canine and human nephropathy in VL are very similar, the data obtained in this study constitute an important contribution to the understanding of canine and human VL nephropathy.

Hyperalgesia induced by Asp49 and Lys49 phospholipases A2 from Bothrops asper snake venom: pharmacological mediation and molecular determinants

The ability of Lys49 and Asp49 phospholipases A(2) (PLA(2)), from Bothrops asper snake venom, to cause hyperalgesia was investigated in rats, using the paw pressure test. Intraplantar injection of both toxins (5-20 micro g/paw) caused hyperalgesia, which peaked 1h after injections. Incubation of both proteins with heparin, prior to their injection, partially reduced this response. Chemical modification of Asp49 PLA(2) with p-bromophenacyl bromide (p-BPB), which abrogates its PLA(2) activity, also abolished hyperalgesia. Intraplantar injection of a synthetic peptide corresponding to the C-terminal sequence 115-129 of Lys49 PLA(2), caused hyperalgesia of similar time course, but varying magnitude, than that induced by the native protein. In contrast, a homologous peptide derived from the Asp49 PLA(2) did not show any nociceptive effect. Hyperalgesia induced by both PLA(2)s was blocked by the histamine and serotonin receptor antagonists promethazine and methysergide, respectively, by the bradykinin B(2) receptor antagonist HOE 140 and by antibodies to tumor necrosis factor alfa (TNFalpha) and interleukin 1 (IL-1). Pretreatment with guanethidine, atenolol, prazosin and yohimbine, inhibitors of sympathomimetic amines, or with indomethacin, inhibitor of the cyclo-oxygenase pathway, reduced Lys49 PLA(2)-induced hyperalgesia without interfering with the nociceptive activity of Asp49 PLA(2). The hyperalgesic response to both myotoxins was not modified by pretreatment with celecoxib, an inhibitor of the cyclo-oxygenase type II, by zileuton, an inhibitor of the lipoxygenase pathway or by N(g)-methyl-L-arginine (LNMMA), an inhibitor of nitric oxide synthase. These results suggest that Asp49 and Lys49 PLA(2)s are important hyperalgesic components of B. asper venom, and that Lys49 and Asp49 PLA(2)s exert their algogenic actions through different molecular mechanisms.

Glomus tumour in the digit of a dog

The gross and microscopical features of a glomus tumour in the digit of a 9-year-old dog are described. The tumour consisted of a red nodule near the nail of the third digit of the right forelimb and appeared painful. The tumour cells, which had round to oval hyperchromatic nuclei and scant cytoplasm, were arranged in sheets around blood vessels, or in nests or duct-like structures. This pattern has not been described previously in canine glomus tumours. Mitotic figures were seen only occasionally. Tumour cells were strongly immunolabelled for vimentin and some expressed smooth-muscle actin and desmin. They were negative for cytokeratins, neuron-specific enolase and CD34. Silver impregnation (reticulin method) stained the reticulum around blood vessels, nests of tumour cells and duct-like structures, and a delicate reticulum was seen around each tumour cell. The morphological, immunohistochemical and histochemical patterns helped in the diagnosis of this glomus tumour.

Aetiology and histopathology of bovine mastitis of espontaneous occurrence

Infectious bovine mastitis is responsible for serious economic losses in dairy cattle breeding. Information about the damages caused by micro-organisms is of great interest and importance. The purpose of the present study was to report on the microbiological and histopathological aspects of the mammary parenchymas of slaughtered dairy cows. A total of 184 mammary glands were examined and samples of mammary parenchyma were collected for microbiological and histopathological examinations. Micro-organisms were isolated from 69.6% samples; 23 (12.5%) of the 184 samples did not show histological changes; inflammatory response was observed in 56 (30.4%) samples; inflammatory response and repair were present in 82 (44.6%) samples; repair process was verified in 23 (12.5%) of the mammary glands. Coagulase-negative Staphylococci were observed in 53.8% of the samples followed by coagulase-positive Staphylococci (7.6%), Prototheca sp. (2.2%) and Streptococcus dysgalactiae (1.6%). Coagulase-negative Staphylococci and coagulase-positive Staphylococci were associated mainly to chronic inflammatory response and chronic inflammatory response and repair. Samples from which no micro-organisms were isolated (n = 56) had no histological changes in 82.6% of the cases. These results were higher (P < 0.05) when compared to the samples with micro-organisms and without histological changes (17.4%).

Effect of low levels of dietary aflatoxin B1 on laying japanese quail

In the present study, 256 7-wk-old Japanese quail were randomly distributed into four experimental groups (64 birds per group) and given rations containing 0 (controls), 25, 50, or 100 (g aflatoxin B, (AFB1)/kg feed for 168 d. Each treatment consisted of four replicates of 16 quail. Egg production and individual egg weight were checked daily. Feed consumption and feed use were determined weekly. Eggs laid in the last day of each 28-d laying period were collected and subjected to individual analysis for specific gravity, Haugh units, shell thickness and percentage eggshell. Results showed that average egg production, feed use, and body weights were not affected (P > 0.05) by AFB1. However, feed consumption was lower (P < 0.05) for groups fed 50 or 100 microg AFB1/kg. Egg weight was significantly lower (P < 0.05) only for groups exposed to 50 and 100 microg AFB1/kg. Average egg specific gravity, Haugh units, and shell thickness were not affected (P > 0.05) by AFB1. Percentage eggshell was higher (P < 0.05) in the group fed the ration containing 100 microg AFB1/kg. Treatment associated lesions were observed only in the liver. Hepatic cell vacuolation with fatty infiltration was observed in all liver samples of quail fed AFB1-contaminated rations. Bile duct proliferation and trabecular disorder were found only in livers of quail on the 100-microg AFB1/kg treatment. Results indicated that chronic exposure to AFB1 at levels above 50 microg/kg could adversely affect quail performance, emphasizing the importance of controlling aflatoxin contamination in quail rations.

Lack of protective action of cysteine against the fetotoxic effect of monocrotaline

Monocrotaline (MCT), a pyrrolizidine alkaloid present in Crotalaria species, has hepatotoxic, nephrotoxic, pneumotoxic and fetotoxic effects. However, the toxic effects of exposure to MCT in adult rats can be prevented by cysteine. Thus, the present study was conducted to evaluate the possible prevention by cysteine of the toxic effects of MCT on pregnant rats. Thirty-six pregnant rats were used. The females in the experimental groups were fed ration containing 0.02% MCT, 0.02% MCT + 1% cysteine, or 1% cysteine from day 6 to day 21 of pregnancy; the control group was fed only common ration for the same period of time. All rats were killed on day 21 of pregnancy and their blood was collected for determination of liver and kidney function. General toxicity to pregnant dams was assessed. Fetuses were removed by caesarian section and embryofetotoxic parameters were examined. Results showed impaired body weight gain in rats fed MCT, with or without cysteine supplementation. Plasma levels of AST, ALT, LDH, GGT, urea and creatinine were increased in MCT animals compared to controls. The pathology study revealed lesions only in dams from the MCT group. The weights of the placentas and fetuses of the MCT and MCT + cysteine groups were significantly lower than those of the control group. Thus, the present data suggests some protective action of 1% of cysteine in ration against the toxic effects of MCT on the dams but not on the litter.

Does prolonged cyanide exposure have a diabetogenic effect?

Cyanide exposure through cassava consumption has been associated with the development of malnutrition-related diabetes mellitus (MRDM). However, there are few experimental reproductions of this disease. In the present study 42 rats received 0, 9.0 or 12.0 mg KCN/kg bw/d for 15 d, 26 pigs were dosed with 0, 2.0, 4.0 or 6.0 mg KCN/kg for 74 d, and 34 goats received 0, 0.3, 0.6, 1.2 or 3.0 mg KCN/kg for 5 mo. At the end of each experimental period, plasma samples were obtained for glucose and thiocyanate measurement, and the pancreas was collected for histopathologic study. No significant differences in plasma glucose concentrations occurred between groups. The pancreas had no pathology. Chronic cyanide exposure did not promote diabetogenic effects in rats, swine or goats, suggesting that cyanide is not responsible for MRDM in humans.

Glue solvent inhalation impairs host resistance to Mycobacterium bovis-induced infection in hamsters

Industrial organic solvents present in glue are among the common used psychotropic drugs in Brazil and perhaps worldwide; but few data are available concerning the toxic effects of glue sniffing, with almost no information about immunotoxicity. This seems interesting because several drugs and environmental chemicals are recognized as potential immunotoxicants. The present study investigated the effects of forced inhalation of a toluene/n-hexane 1:1 mixture on hamster resistance to Mycobacterium bovis. Adult hamsters were divided at random into 3 equal groups. Animals of Groups E and E inhaled the mixture of toluene/n-hexane twice daily for 37 d. Group C was placed for the same period of time in identical chambers free of solvents. Two days after the beginning of the experiment, Groups E and C were injected ip with 0.5 ml of an activated suspension of M. bovis; Group E received the same volume of a control solution. Hamsters inhaling the toluene/n-hexane mixture (E) exhibited increased weight loss, increased scores of M. bovis colony forming units isolated from liver, lung and spleen, increased granulomatous areas in the liver, lung and spleen. Inhalation of the toluene/n-hexane mixture for 37 d also increased serum cortisol compared to control hamsters. Tuberculosis is an infection with an intracellular bacterium in which sensitivity is determined mainly by host response. The present data demonstrated impaired defense against M. bovis in hamsters inhaling a toluene/n-hexane mixture for 37 d. Since macrophages are the architectural and functional units of the granulomas in tuberculosis, and no data were found about glue solvent effects on cellular immunity, the present data suggest an indirect effect of glue solvents on macrophage/lymphocyte activity via stress induction and central nervous system stimulation of hormonal (ACTH/cortisol) secretion and/or autonomic nervous system activity.

CD4(+) T cells participate in the nephropathy of canine visceral leishmaniasis

Renal involvement in visceral leishmaniasis (VL) is very frequent. The renal lesions of humans and dogs are similar but their pathogenesis has not been clearly elucidated. There is growing evidence that the cellular immune response is involved in the pathogenesis of immunologically mediated glomerulonephritis. Since T cells could participate in the pathogenesis of nephropathy, in the present study we investigated the possible involvement of CD4(+) and CD8(+) T cells in the nephropathy of canine VL. Six dogs naturally infected with Leishmania (Leishmania) chagasi from the endemic area in the Northeast of Brazil, the town of Teresina in the State of Piauí, were studied. An expressive inflammatory infiltrate of CD4(+) T cells both in glomeruli and in interstitium was present in 4 animals and absent in 2. CD8(+) T cells were detected only in one animal. CD4(+) T cells alone were observed in 3 animals; when CD8+ T cells were present CD4(+) T cells were also present. CD4(+) T cells were observed in cases of focal segmental glomerulosclerosis, diffuse membranoproliferative glomerulonephritis, diffuse mesangial proliferative glomerulonephritis and crescentic glomerulonephritis. CD8(+) T cells were present only in a case of crescentic glomerulonephritis. Leishmania antigen was detected in glomeruli and in interstitial inflammatory infiltrate in 4 animals and immunoglobulins were observed in 4 dogs. In this study we observed that T cells, in addition to immunoglobulins, are present in the renal lesion of canine VL. Further studies are in progress addressing the immunopathogenic mechanisms involving the participation of immunoglobulins and T cells in canine VL nephropathy.

Effects of treatment with amphetamine and diazepam on Mycobacterium bovis-induced infection in hamsters

Tuberculosis is an example of an infection with an intracellular bacterium in which sensitivity is determined mainly by the host response. Macrophages are the architectural and functional units of the granulomas described in tuberculosis. Treatment with amphetamine (AMPH) and diazepam has been reported to decrease macrophage activity. The present experiment was undertaken to investigate the effects of AMPH and/or diazepam given alone or in combination on hamster resistance to Mycobacterium bovis. The effects of these treatments on serum cortisol levels were also studied. Adult hamsters were treated i.p. with AMPH (group E1 = 1.0 or 2.0 mg/kg/day), with AMPH (group E2 = 1.0 or 2.0 mg/kg/day) plus diazepam (2.0 mg/kg/day), with diazepam (group E3 = 2.0 mg/kg/day), or with control vehicles (1.0 ml/kg/day) for 40 days. Six days after the beginning of the treatments, the animals received identical inoculum concentrations of M. bovis. Hamsters treated with AMPH plus diazepam exhibited: 1) increased weight loss; 2) increased mortality; 3) increased scores of M. bovis colony forming units (CFU) isolated from liver, lung and spleen; 4) increased granuloma areas measured in the liver, lung and spleen. These effects were not induced by AMPH (1.0 or 2.0 mg/kg/day) given alone and were produced by diazepam (2.0 mg/kg/day) treatment per se. Furthermore, AMPH (2.0 mg/kg/day) and diazepam (2.0 mg/kg/day) given alone or in combination for 20 days increased the serum levels of cortisol in relation to control hamsters, with the effect being higher in the animals treated with both drugs. The present data, which demonstrate an impaired defense against M. bovis in hamsters treated with AMPH plus diazepam or with diazepam alone, were tentatively explained on the basis of a direct and/or indirect action of the drugs on macrophage/lymphocyte activity. In the former case, the effects may be related to stimulation of peripheral benzodiazepine receptor sites (PBR) present on macrophages/lymphocytes and/or to a direct effect of ACTH on immune cells, while in the latter they may be mediated by cortisol via PBR and ACTH stimulation of the adrenals.

Antimicrobial susceptibility of Staphylococcus spp. isolated from mammary parenchymas of slaughtered dairy cows

The high prevalence of the great resistance to antimicrobials shown by the aetiological agents of infectious bovine mastitis, often leads to chronic recurrent mastitis, one of the main causes of early culling of dairy cows. The purpose of this study was to determine the in vitro susceptibility pattern of Staphylococcus spp. isolated from mammary parenchymas of slaughtered dairy cows, to different anti-microbials. A total of 45 Staphylococcus spp. strains [33 coagulase-negative Staphylococcus (CNS) and 12 Staphylococcus aureus (SA)] were used. These strains were tested with 12 different antimicrobials by the Kirby and Bauer standardized disc diffusion method; 84.44% and 86.66% of the 45 strains were resistant to ampicillin and penicillin, respectively. The highest sensitivity was to cephalothin (84.44%), gentamicin (80%) and to sulphazotrin (77.77%). CNS showed higher resistance (P < 0.05) than SA. The in vitro susceptibility pattern of Staphylococcus spp. strains isolated from mammary parenchymas studied in the present investigation was similar to that observed in recent studies of in vitro and in vivo susceptibility patterns of Staphylococcus spp. isolated from cases of bovine mastitis.

Fetotoxicity and reproductive effects of monocrotaline in pregnant rats

Four groups of 12 pregnant Wistar rats each were fed with rations containing 0, 0.01, 0.015 and 0.02% of monocrotaline (MCT) from day 6 to 21 of gestation. Liver weights of the dams from the three experimental groups were significantly lower than those from the control group. Serum levels of aspartate aminotransferase; alkaline phosphatase; lactate dehydrogenase; gamma glutamyltransferase, urea and creatinine were significantly higher in dams from MCT 0.02% group. The weights of the placenta, fetuses and fetal lungs of the 0.02% MCT group were significantly lower than those of the control group. A mild to moderate interstitial pneumonia and liver lesions were observed in dams ingesting 0.02% of MCT. These results showed the toxicity of MCT to the females that ingested 0.02% and their fetuses. Because there was no differences on the weight gains and food and water consumption of the dams it is suggested that this toxic effects in the fetuses was caused by the diffusion of MCT through the placenta. No significant differences were observed in the frequency of skeletal and visceral malformation or anomalies between the control and treated groups suggesting that MCT had no teratogenic effect.

Effects of diazepam on Mycobacterium bovis-induced infection in hamsters

The in utero exposure of hamsters to low doses of diazepam results in impaired host defense against Mycobacterium bovis during adulthood. Delayed developmental immunotoxicity, however, represents a specific situation that might not be general. The present experiment was undertaken to investigate the effects of diazepam on hamster resistance to M. bovis using adult animals. The effects of diazepam treatment on serum cortisol levels were also studied. Adult hamsters (N = 10 for each group) were treated with diazepam (E1 = 1. 0, E2 = 2.0 or E3 = 3.0 mg kg-1 day-1 subcutaneously) or with control solution (C) for 30 days. Seven days after the beginning of the treatment, the animals received identical inoculum concentrations of M. bovis. Hamsters treated with the higher (2.0 and 3.0 mg kg-1 day-1) doses of diazepam exhibited: 1) increased granuloma areas in the liver (C = 1.81 +/- 1.39, E2 = 10.29 +/- 4.64 and E3 = 15.80 +/- 4.82) and lung (C = 0.54 +/- 0.55, E2 = 6.28 +/- 3.85 and E3 = 6.31 +/- 3.56) and 2) increased scores of M. bovis colony-forming units isolated from liver (C = 2.0, E2 = 3.0 and E3 = 3.5), lung (C = 1.0, E2 = 3.0 and E3 = 3.5) and spleen (C = 1.0, E2 = 2.5 and E3 = 4.0). These effects were dose dependent, and were not detected or were less severe in animals treated with the lowest (1.0 mg/kg) dose of diazepam as well as in those of the control group. Furthermore, diazepam treatment (3.0 mg kg-1 day-1 for 30 days) increased (E3 = 71.32 +/- 2.99; N = 10) the serum levels of cortisol compared to control hamsters (C = 22.61 +/- 2.75; N = 10). The present data, that demonstrate an impaired defense against M. bovis in adult hamsters treated with diazepam, were tentatively explained on the basis of a direct and/or indirect action of diazepam on the cytokine network. The effects may be related to stimulation of peripheral benzodiazepine receptor binding sites (PBR) by macrophages and/or lymphocytes, or they may be mediated by PBR stimulation of the adrenals.

Effects of prenatal diazepam treatment on Mycobacterium bovis-induced infection in hamsters

In utero exposure of rats to low dosages of diazepam has been found to result in depression of cellular and humoral immune responses during adulthood, with marked changes in macrophage spreading and phagocytosis. The present experiment was undertaken to investigate the resistance of adult hamsters to Mycobacterium bovis after prenatal exposure to diazepam. Time-pregnant hamsters were exposed to diazepam (1.0 or 1.5 mg kg(-1) day(-1) subcutaneously) or vehicle from gestational day 9 to 15. A total of 36 different litters (12 of them control and 12 for each experimental group) born after a 16/17-day gestation were used. One male from each litter was infected twice with identical inoculum concentrations of M. bovis at 75 and 107 days of age. This infection model involves the participation of macrophages and T and B cell populations. The animals prenatally exposed to the higher (1.5 mg/kg) dose of diazepam exhibited: (1) increased weight loss, (2) increased mortality, (3) increased granuloma areas measured in the liver, lung and spleen, (4) increased spleen weight, and (5) increased scores of M. bovis colony forming units (CFU) isolated from liver, lung and spleen. These effects were dose-dependent, and were not detected or were less severe in animals treated with the lower (1.0 mg/kg) dose of diazepam as well as in those of the control group. The present data demonstrate an impaired defence against M. bovis in adult hamsters after in utero exposure to a dosage of 1.5 mg/kg of diazepam.

Beta-carotene reduces the ductular (oval) cell reaction in the liver of Wistar rats submitted to the resistant hepatocyte model of carcinogenesis

The morphology of livers of Wistar rats treated with beta-carotene (BC), vitamin A (VA, retinol acetate) or corn oil (CO, controls) and submitted to the resistant hepatocyte model of carcinogenesis was studied. Preneoplastic lesions (PNL) were smaller and less numerous in the BC group. The latter group also presented fewer placental glutathione-S-transferase (GST-P) positive and hematoxylin and eosin (H&E) distinguishable PNL, with smaller mean areas and smaller mean areas of the liver occupied by PNL. Clear cell foci predominated in BC livers. In picrosirius-stained liver sections, fibrosis, whether or not accompanying the bile ductular cells, surrounded only 16.67% of PNL in the BC group, as compared to 35.71% in the VA group and 87.72% in the CO group. Moreover, the ductular cell reaction was smaller in the BC group. Smooth muscle actin-positive cells surrounded some PNL, mostly in CO rats, and less frequently in the VA and BC groups. Examination by transmission electron microscopy (TEM) showed that cells with nuclei similar to those of perisinusoidal cells, devoid of cytoplasmic fat globules, probably represented myofibroblasts derived from Ito cells and accompanied the ductular cell reaction. On the basis of these results, we suggest that BC reduced not only the PNL but also the ductular (oval) cell reaction in this experimental model.

Red blood cell phenotypes in alpha-thalassemias in the Spanish population

BACKGROUND AND OBJECTIVE

alpha-thalassemia is very common on all thalassemic geographical regions. The present work aimed at analyzing the relationship between the degree of microcytosis and hematological parameters and the type of alpha-thalassemic mutation.

DESIGN AND METHODS

Five hundred and thirty-six subjects with 4 kinds of alpha-thalassemia were examined using established techniques that determined all hematological parameters, and globin synthesis and molecular biological techniques to study the DNA of globin genes by Southern blotting.

RESULTS

Adult carriers of alpha (+)-thalassemia (-alpha/alpha alpha) present very few hematological alterations. In a statistical comparison with normal individuals (alpha alpha/alpha alpha), significant differences were found between the hemocytometric data and the MCV and MCH of heterozygous alpha + thalassemia and the heterozygous alpha zero or homozygous alpha + genotype. Hb H disease was detected in 15 patients, presenting a severe degree of anemia, a significant increase in RDW and globin chain synthesis with an alpha/beta ratio of 0.5 +/- 0.1.

INTERPRETATION AND CONCLUSIONS

These data provide reference values for geographical areas where alpha + thalassemia is common. These hematocytometric data, together with hemoglobin analysis, could be useful as a future reference data for new patients diagnosed with alpha-thalassemia.

[Tuberculosis lymphadenitis in slaughtered swine from the State of São Paulo, Brazil: microscopic histopathology and demonstration of mycobacteria]

INTRODUCTION

As the occurrence of tuberculosis lymphadenitis in swine constitutes a public health risk, especially in immunosuppressed individuals, the distribution of tuberculoid lesions and the presence of microbacteria in lymph nodes and hepatic and muscular tissue in swine for slaughter, in the State of S. Paulo, SP (Brazil), in the period from 1993 to 1994, were studied. MATERIAL E METHOD: Tuberculous lesions in 60 carcasses of swine, slaughtered at abattoirs during the period 1993-1994, were studied. When macroscopic lesions were observed, a representative sampling of lymph nodes, hepatic and muscular tissues (masseter and diaphragm) were examined using histopathological and microbacterial isolation techniques.

RESULTS

The macroscopic lesions were found predominantly in mesenteric lymph nodes. The MAI Complex (M.avium-intracellulare) was isolated mainly in the carcass group that showed lesions and was not found in the control group. Microorganisms of the MAI Complex were not isolated from hepatic and muscular tissues.

CONCLUSION

No clear relationship between the type of mycobacteria isolated and the macroscopic lesions observed during the carcass inspection was found.

Squamous cell carcinoma of the renal pelvis with metastasis in a dog

The gross and microscopical features of a squamous cell carcinoma of the renal pelvis in an 18-year-old dog are described. This is a rare tumour originating from transitional cells of the pelvis. The tumour, which invaded the renal parenchyma and capsule and the small intestinal wall, metastasized to the lungs. Tumour cells expressed cytokeratin 8 and were arranged in a pattern similar to that of a squamous cell carcinoma found elsewhere, with prickle cells and horny pearls. The tumour was not diagnosed clinically but was found at necropsy. The presence of pelvic calculi in this dog is suggested as a cause of transitional cell squamous metaplasia and malignant transformation.

[Anticentromere antibodies and lung disease without skin involvement]

Anticentromere antibodies are closely related to systemic sclerosis and basically to limited cutaneous form. Two patients with different forms of lung disease, positive anticentromere antibodies and absence of the characteristic skin involvement of the systemic sclerosis are presented.

Acute, subchronic and chronic 2,4-dichlorophenoxyacetic acid (2,4-D) intoxication in rats

The acute, subchronic and chronic toxicities of 2,4-dichlorophenoxyacetic acid (2,4-D) were studied ir rats. Animals were exposed acutely (600 mg/kg), subchronically (200 ppm for 30 d) and chronically (200 ppm for 180 d) to 2,4-D by the oral route. Clinical, laboratory and histopathological methods were used as indicators of toxicity. After acute exposure, the herbicide decreased locomotor activity and induced ataxia, sedation, muscular weakness (mainly of the hind quarters) and gasping for breath; increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (AP), amylase activities and creatinine levels; decreased total protein (TP) and glucose levels; and increased hematocrit values. Subchronic and chronic 2,4-D exposures did not induce overt clinical signs or symptoms of intoxication. However, subchronic herbicide exposure increased AST activity and albumin and hematocrit values, and chronic exposure increased AST, AP and LDH activities, decreased amylase and glucose levels, but did not change hematocrit values. Chromatographic analysis of the serum of chronically exposed rats showed the presence of the herbicide; the amount found (3.76 +/- 1.16 micrograms/ml) suggested the absence of 2,4-D accumulation within the body. Although macroscopic or histopathological lesions were not observed in acutely, subchronically or chronically 2,4-D exposed rats, the laboratory data obtained suggest tissue injuries after dosing, since the results are considered early indicators of primarily hepatic and muscle tissue damage.

[Remission induction treatment in adults with acute myeloid leukemia. 8-year experience with 2 successive protocols]

We report our eight year experience remission induction therapy in adult patients with acute myeloblastic leukemia. Overall 67 patients were treated, with a mean age of 43.3 years (range 15-75). Two treatment protocols were used. Complete remission (CR) was achieved in 23 patients of 39 receiving protocol A (58%). The 28 last patients were treated with the more aggressive protocol B, and CR was achieved in 23 patients (82%). CR was achieved in 68% of the overall group. The most outstanding predictive factors were age above 30 years, and M-5 morphology as indicating a poor prognosis.

[Cauda equina syndrome with plantar perforating ulcer and neurogenic osteoarthropathies in a case of rheumatismal pelvospondylitis]

The authors report a case of ankylosing spondylitis complicated by a cauda equina syndrome presenting with a plantar perforating ulcer and lesions of neuropathic arthropathy of the foot. On the basis of an analysis of 54 cases published in the literature they review the principal aspects of this complication of ankylosing spondylitis. Neurological manifestations occur late after several decades of progression of the disease. Urinary sphincter problems are common whilst trophic disturbances remain rare. Myelography and, above all, lumbar CAT scan reveal characteristic and stereotyped anatomical lesions: widening of the dural sac in its posterior part with meningoceles eroding the posterior vertebral arch. The pathogenic mechanisms are unknown. The authors suggest that lesions may start with posterior epidural inflammation rather than a primary process of arachnoiditis as has been mentioned in earlier publications.

Prevalence of feline leptospirosis: serologic survey and attempts of isolation and demonstration of the agent

The occurrence of leptospiral infection in cats was determined through the detection of specific antibodies based on the results of microscopic agglutination test and the attempts of isolation and histological demonstration of leptospires from the kidneys of these animals. Of 172 serum samples examined by microscopic agglutination test, 22 (12.8%) were positive with titers greater than or equal to 100. The most frequent serovar was pomona. In relation to the sex, significant differences were not seen; however the age distribution showed that feline leptospirosis is more frequent in adult cats. The attempts for isolation and demonstration of L. interrogans from renal parenchyma by culture or Warthin Starry technics were unsuccessful.