Postoperative adiponectin levels in pediatric patients undergoing open heart surgery.

BACKGROUND: Adipose tissue is an important endocrine organ that secretes cytokines, including adiponectin, levels of which are negatively correlated with the severity of the inflammatory process. Aim. To assess the time course of adiponectin levels following open heart surgery with cardiopulmonary bypass and its correlation with early postoperative outcomes. MATERIALS AND METHODS: Blood samples were obtained from 24 children undergoing cardiac surgery and analyzed for adiponectin, C-reactive protein, and other inflammatory markers. RESULTS: Baseline adiponectin levels were negatively correlated with patients' preoperative weight and age. Postoperative adiponectin levels decreased compared to baseline (P = 0.01) and correlated negatively with duration of cardiopulmonary bypass (r = -0.438, P = 0.037), length of stay in the pediatric intensive care unit (r = -0.457, P = 0.025), and the inotropic score (r = -0.471, P = 0.02). Adiponectin levels were positively correlated with sVCAM 1 levels; however, there was no correlation between adiponectin levels and sP selectin, tPA, MCP1, and sCD40. CONCLUSIONS: The inflammatory response after open heart surgery with cardiopulmonary bypass is associated with a reduction in adiponectin levels. Prolonged or more complicated surgery induced a more substantial inflammatory process characterized by a significant reduction in adiponectin levels over time and a delayed return to baseline levels.

Coexistence of granulomatous enteric inflammation and neoplasia in an adult sheep.

A 7-year-old dairy sheep suffering from chronic loss of weight without diarrhea or anorexia was euthanized after failing to respond to any treatment (antibiotic and antiparasitic). The main findings at the necropsy of this animal were multifocal miliary nodules in several organs, mainly in the Peyer's patches of the small intestine, and a segmental thickening of the jejunal wall. Histologic examination of the samples taken at the necropsy showed a multifocal chronic granulomatous inflammation, with mineralization and caseous necrosis at the core of the larger granulomas and scarce intrahistiocytic acid-fast bacilli consistent with a disseminated digestive tuberculosis. Polymerase chain reaction and bacteriological culture from these samples confirmed Mycobacterium avium subsp avium to be the etiologic agent of this infection. Histologically, the cause of the segmental thickening of the jejunal wall was found to be a small intestine adenocarcinoma, which in some areas coexisted with the granulomatous lesion.

Pathological findings in young and adult sheep following experimental infection with 2 different doses of Mycobacterium avium subspecies paratuberculosis.

Mycobacterium avium subsp paratuberculosis (Map) is assumed to infect young ruminants; however, little is known concerning the possibility of adult animals becoming infected. An experimental infection was conducted to establish the effect of age and doses of Map on susceptibility to paratuberculosis in sheep. Sixteen of twenty-four 1.5-month-old Churra lambs and 23 of 30 adult ewes (from 2-11 years old) were orally challenged with an ovine field strain of Map. Thirteen ewes and 8 lambs were infected with a high dose (HD) and 10 adult sheep and 8 lambs with a low dose (LD) of Map. The remaining animals were unchallenged controls. Animals were euthanized at 110 to 120 and 210 to 220 days postinfection. Histological, bacteriological, and nested polymerase chain reaction (PCR) studies were conducted in samples of intestine and related lymphoid tissue (Peyer patches, lymph nodes). Animals were classified according to their lesions. The number of granulomas was counted in 3 tissue sections from each sample. Only the HD groups showed lesions associated with paratuberculosis (92.3% of ewes and 100% of lambs). Adults had lesions characterized by few small demarcated focal granulomas restricted to the lymphoid tissue, whereas granulomas were more numerous and larger, appearing in the lamina propria unrelated to lymphoid tissue, in the lambs. Only HD-infected lambs were positive to culture, whereas nested PCR also detected positive HD ewes and some LD animals. These results suggest that adult sheep can become infected by Map, as seen by the development of lesions, but they are focal and restricted to the lymphoid tissue.

Acute and chronic disease associated with naturally occurring T-2 mycotoxicosis in sheep.

A flock of approximately 1,000 sheep were exposed intermittently to food contaminated with T-2 toxin (T-2), a potent type-A trichothecene mycotoxin produced primarily by Fusarium sporotrichioides and Fusarium poae. In the acute stage of the intoxication, affected sheep developed anorexia, decreased water consumption, ruminal atony, soft faeces and apathy. One hundred and ninety of the exposed sheep died. The main gross lesions observed in animals dying during the acute disease were rumenitis and ulcerative abomasitis, depletion of lymphocytes in lymphoid organs, necrosis of the exocrine pancreas, myocarditis and intense oedema of the skin and brain. Sheep developing the chronic stage of disease showed weight loss and reproductive inefficiency and the main pathological features observed in animals dying during this stage were gastrointestinal inflammation, myocardial fibrosis and necrotic and suppurative lesions in the oral cavity. Opportunistic infections (e.g. mycotic mastitis or parasitic pneumonia) were also identified in these animals. Increased serum concentrations of lactate dehydrogenase and creatine kinase were observed, most likely related to heart lesions. T-2 toxins were detected in all samples of the diet of these animals that were analyzed. The changes in the sheep reported here are similar to those described previously in experimental studies. Lesions observed in the present animals suggest an additional cardiotoxic effect of T-2 in sheep.

Pathological features of systemic necrotizing vasculitis (polyarteritis nodosa) in sheep.

Polyarteritis nodosa (PAN) is a systemic vasculitis of unknown aetiology affecting small- and medium-sized arteries of multiple organ systems without involvement of pulmonary arteries. This report describes four cases of PAN in sheep from different flocks. Three of these animals displayed clinical signs of locomotor disturbance. Gross necropsy findings included bilateral nodular thickening of vessels together with thromboses and aneurysms at several locations. Microscopically, small- to medium-sized arteries of the kidneys, ovary, uterus and skin were consistently involved and other locations were affected less frequently. Arteries within the lung were normal in all animals. Vascular lesions were characterized by focal fibrinoid necrosis, rupture of the internal elastic lamina and transmural infiltration of mononuclear inflammatory cells, extending into the perivascular tissue. In the kidney, many arteries showed narrowing or occlusion of the lumen and marked fibrosis. The distribution of arterial lesions was segmental, showing alternation of affected and microscopically normal areas. Immunohistochemical studies did not identify immune complex deposition. The inflammatory infiltrates were composed of T lymphocytes and macrophages, suggesting that a cell-mediated immune response may be involved in the pathogenesis of this disease.

Leptin and the post-operative inflammatory response. More insights into the correlation with the clinical course and glucocorticoid administration.

BACKGROUND: Cardiac surgery involving cardiopulmonary bypass (CPB) causes a systemic inflammatory process which can lead to multiple organ failure and postoperative morbidity. Recent animal and human studies suggested a possible involvement of leptin in the systemic inflammatory response. AIM: To characterize the response of leptin to open heart surgery (OHS) and the relationship between the time course of leptin levels and the post-operative clinical course, and to examine the effect of exogenous glucocorticoids. PATIENTS AND METHODS: Forty-seven pediatric patients, undergoing OHS for congenital heart disease were studied. Thirty-four patients (Group 1) received methylprednisolone during CPB while 13 (group 2) did not. Serial blood samples were collected perioperatively and up to 24 h after surgery, and assayed for leptin and cortisol. RESULTS: All patients' leptin levels decreased significantly during CPB (to 44-48% of baseline, p<0.001); they then increased, peaking at 12 h post-operatively. The levels of groups 1 and 2 were similar up to 8 h post-operatively; thereafter, those of group 1 were significantly higher. Recovery of leptin levels in patients with a more complicated post-operative course was comparatively slower. Cortisol levels of all patients increased significantly during CPB (p<0.001), gradually decreasing afterwards. Cortisol and leptin levels were inversely correlated in both patients' groups. CONCLUSIONS: CPB is associated with acute changes in circulating leptin levels. A complicated postoperative course is associated with lower leptin levels which are inversely correlated with cortisol levels. Leptin may participate in post-CPB inflammatory and hemodynamic responses.

Maedi-visna: the meningoencephalitis in naturally occurring cases.

Lesions were examined at different levels of the central nervous system (CNS) in 64 sheep with natural maedi-visna (MV) meningoencephalitis. All animals showed lesions in more than one of the CNS locations examined; the lesions in the cranial regions were periventricular, while those in the spinal cord affected the white matter funicles. Lesions were found particularly in the cerebellar peduncles (non-suppurative meningoencephalitis), followed by the corpus callosum, hippocampus and thoracic spinal cord. Vascular, infiltrative and malacic histopathological patterns were recognized. One pattern predominated in each section examined, although mixed forms occurred. Vascular lesions occurred with similar frequency at all CNS levels, but infiltrative and malacic lesions predominated at rostral and caudal levels, respectively. Cells consistent with macrophages and shown immunohistochemically to be associated with MV virus were seen in malacic and infiltrative lesions, at the periphery of damaged areas.

Variation in the immuno-pathological responses of lambs after experimental infection with different strains of Mycobacterium avium subsp. paratuberculosis.

Ruminant infection by Mycobacterium avium subsp. paratuberculosis (MAP) causes a granulomatous inflammatory response in the intestine and associated lymph nodes. Differences either in the affected organs or in the inflammatory infiltrate were observed between species and individuals. Such differences are usually attributed to variations in host immune responses or to inconsistent effects among different MAP strains. To evaluate if different MAP strains induce different immuno-pathological responses in lambs, 28 one-month-old individuals were divided into six groups and inoculated with different MAP strains. Groups 1 and 2 were inoculated with two bovine strains isolated in Argentina that showed different genetic patterns after BstEII-IS900-RFLP (hereafter strains E and A respectively). Group 3 was inoculated with a bovine strain isolated in Spain obtained after a previous step of culture (patterns C1). Group 4 was inoculated with a homogenate of intestinal mucosa of a clinical case affected by the same bovine strain as that of group 3. Group 5 was inoculated with an ovine strain that was directly purified from the intestinal mucosa of a clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral immune responses were assessed until 150 days post-infection (dpi), when lambs were humanely killed. Pathological studies were performed in tissues from the intestine and lymph nodes. Lesion types and inflammatory infiltrates were examined as indicators of pathogenicity. All the lambs infected with bovine MAP strains showed a common lesion pattern regardless of the strain type. Such pattern was characterized by focal lesions mainly in the mesenteric lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the granulomas as well as the presence of numerous giant cells. Differences in lesion severity were observed among groups: lambs from groups 1 and 2 had the highest number of granulomas and the largest lymph node area affected. Lesions in animals from group 5 (infected with an ovine strain) were more severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis or giant cells were never detected in this group. These results indicate that the MAP strain type induces different pathological responses in lambs.

Acute psychotic stress is associated with decreased adiponectin serum levels.

OBJECTIVE: To determine the effect of acute psychotic stress on adipokine secretion in non-diabetic subjects. RESEARCH DESIGN AND METHODS: Adiponectin, leptin, and cortisol serum levels were determined in 39 non-diabetic patients with acute psychotic stress reaction admitted to a psychiatric ward. The clinical global impression (CGI) score was used to evaluate the level of psychotic stress. Insulin sensitivity (IS) was determined by the homeostasis model assessment (HOMA). Patients were re-assessed 2 weeks after admission. During hospitalization patients were treated for variable times with either phenothiazines or thioxanthenes. RESULTS: The mean CGI score decreased significantly with time: 5.3+/-0.8 and 2.6+/-0.8 on admission and after 2 weeks respectively (p<0.001). On admission, the mean adiponectin level was significantly lower in patients compared to normal controls: 15.3+/-8.2 mug/ml and 26+/-12.8 mug/ml, respectively (p=0.02). It increased significantly after 2 weeks to 18.2+/-10 mug/ml (p=0.003). By contrast, the leptin and cortisol levels did not change significantly. No correlation was found between the changes in individual CGI scores and adiponectin levels. However, female patients with the highest stress on admission demonstrated the lowest adiponectin levels and insulin sensitivity: p=0.002 and 0.03 respectively. CONCLUSIONS: These data suggest a link between acute psychotic stress reaction and decreased serum adiponectin levels. Further studies are recommended to determine the strength of this association.

Maternal serum adiponectin levels during human pregnancy.

OBJECTIVE: Pregnancy is a unique situation characterized by insulin resistance. The role of adiponectin, an insulin-sensitizing hormone, has not been completely clarified during pregnancy. The aim of this cross-sectional study was to evaluate adiponectin levels during pregnancy and postpartum. STUDY DESIGN: Adiponectin and leptin levels were tested in 80 pregnant women, 20 in each trimester (mean gestational age 10.5+/-1.9; 19.3+/-4.9; 39.3+/-0.8 weeks,) as well as 4 days postpartum. RESULTS: Adiponectin levels during first (13.3+/-3.6 micro g/ml), second (12.6+/-4.4 micro g/ml) and third trimester (11.2+/-3.7 micro g/ml) did not differ and were significantly higher than postpartum levels (8.8+/-2.1 micro g/ml; P<0.0001, P<0.004 and P<0.02, respectively). CONCLUSION: Despite increased insulin resistance during pregnancy, no significant alterations in adiponectin levels were observed. This may imply that the regulation of adiponectin during gestation is altered. The elevated gestational adiponectin levels are consistent with increased 'adiponectin resistance' during pregnancy.

Natural cases of visna in sheep with myelitis as the sole lesion in the central nervous system.

Of 118 sheep with visna, 12 showed myelitis as the only nervous lesion. They were ovine lentivirus (OvLV)-seropositive and provirus DNA was demonstrated by LTR-PCR in all the samples with lesions. Clinically, all showed hindlimb paralysis and some were completely recumbent. Grossly, a swollen and discoloured area was identified in the white matter in 10 sheep. Microscopical changes consisted of a wedge-shaped area of non-suppurative leucomyelitis with mononuclear perivascular cuffing, demyelination and white matter degeneration. Except for two samples, grey matter was affected adjacent to severe white matter lesions. Three different microscopical patterns of lesion were identified, all having in common the presence of perivascular inflammation: the so-called vascular pattern was characterized by perivascular cuffs with minimal lesions in the adjacent neuroparenchyma; the malacic pattern, which was the commonest type, was characterized by severe white matter destruction and small numbers of macrophages; and the infiltrative pattern was characterized by a severe infiltrate of histiocytes in the parenchyma. Maedi-visna virus antigen was detected immunohistochemically only in areas with lesions, and the degree of immunolabelling was unrelated to the severity of the damage. Diagnosticians should bear in mind that a considerable number of visna cases show only spinal cord lesions. Examination of paraffin wax-embedded samples by LTR-PCR and immunohistochemistry would seem useful in confirming a histopathological diagnosis of visna from spinal cord samples.

Diagnosis of the nervous form of Maedi-Visna infection with a high frequency in sheep in Castilla y Leon, Spain.

Between 1997 and March 2004, the nervous form, or visna, of maedi-visna infection was diagnosed in 71 of 1631 sheep (4.35 per cent) examined in the Castilla y León region of Spain, of which 634 had shown nervous signs. The presence of the virus was confirmed by immunohistochemistry and in some cases by pcr on frozen-thawed or paraffin-embedded tissue samples. The main clinical signs were hindleg ataxia and paresis, but blindness or nystagmus were also observed. Thirty-three of the affected sheep (46.5 per cent) were two years old or younger. The affected sheep showed variable degrees of a non-suppurative meningoencephalitis, and immunohistochemistry identified positive cells in all cases, with no relation to the intensity of the inflammatory lesion.

Histopathological classification of lesions associated with natural paratuberculosis infection in cattle.

Paratuberculosis-associated lesions in 116 naturally infected adult cows, with or without clinical signs, were classified histopathologically. Tissue samples obtained focused on gut-associated lymphoid tissue. Lesions were divided into five categories. Focal lesions (n=68 cases), consisted of small granulomas in the ileal and jejunal lymph nodes or the ileocaecal lymphoid tissue. In the multifocal type (n=13 cases), small granulomas or scattered giant cells appeared in some intestinal villi, as well as in the lymph nodes. Diffuse multibacillary lesions (n=15 cases), associated with severe granulomatous enteritis affecting different intestinal locations and lymph nodes, were formed by macrophages containing large numbers of acid-fast bacilli. In diffuse lymphocytic lesions (n=3 cases), lymphocytes were the main inflammatory cells, with some macrophages or giant cells containing few if any mycobacteria. In diffuse intermediate forms (n=17 cases), the infiltrate was formed by abundant lymphocytes and macrophages, and mycobacteria were present to varying degrees related to the number of macrophages. Clinical signs and gross lesions were mainly associated with diffuse forms. Thickening of the intestinal wall, which was the most common macroscopical finding, was related to the degree of submucosal change. Mycobacterium avium subsp. paratuberculosis was identified by culture or PCR in all cows with diffuse lesions, and in 55.5 and 37% of those with multifocal or focal forms, respectively. The importance of sampling the ileal and caudal jejunal lymph nodes to find histological lesions of paratuberculosis in cattle is emphasized.

Giant cell tumour of bone in a cat with extraskeletal metastases: pathological and immunohistochemical study.

A case of giant cell tumour of bone (GCTb) in the lung and in a subcutaneous mass located in the right flank, with a probable primary origin in the mid-diaphysis of the right tibia, was described in a 8-year-old female cat. Numerous multinucleated giant cells were homogeneously distributed among a population of ovoid or spindle-shaped mononuclear cells. All of them were positive for vimentin suggesting a mesenchymal origin. Spindle-shaped tumour cells resemble fibroblastic cells, showing collagen fibres in their vicinity. Ovoid mononuclear cells are similar to macrophages, with a cytoplasm rich in electron-dense lysosomes. Multinucleated giant cells appear morphologically similar to osteoclasts. These findings are supported for the positive reaction to tartrate-resistant acid phosphatase (TRAP) and lysozyme, encountered only in ovoid and multinucleated giant cells. No immunoreactivity against human oestrogen receptors was observed in the nuclei of any neoplastic cells.

Increased propensity for amyloidogenesis in male mice.

BACKGROUND: The male sex is a risk factor for reactive amyloidogenesis in several disease entities. Environmental, socioeconomic or genetic factors may underlie this male preponderance. This study was aimed at discovering whether male sex predisposes to reactive amyloidosis also in mice and to elucidate some of the hormonal associations of this risk. METHODS: Male and female Swiss mice were subjected to an established amyloid induction protocol and the amount of their splenic amyloid was determined and compared. The effect of estrogen, progesterone, testosterone and adrenalin on amyloidogenesis was studied in both sexes by administering these hormnones during amyloid induction and comparing the amount of splenic amyloid of the study mice with the control mice which received the amyloid induction protocol alone. RESULTS: Amyloid deposition appeared to be more abundant in male mice. This gender difference was not associated with any of the 3 sex hormones tested. Despite an expected increment, adrenalin caused an attenuation of amyloid deposition. CONCLUSIONS: The preferential expression of reactive amyloidosis in male mice seems to be unrelated to the common sex hormones. Increased production of other hormones such as adrenalin, or perhaps an augmented susceptibility to their effect, may cause gender differences by suppressing female amyloidogenesis. Our study favors the hypothesis of genetic predisposition as the mechanism leading to sex differences in amyloidogenesis. Further validation of our findings in gonadal ablated models and other amyloid induction protocols is warranted.

Circulating leptin levels after cardiopulmonary bypass in children.

OBJECTIVE: To characterize the dynamics of circulating leptin in children after cardiac surgery with cardiopulmonary bypass (CPB), which is known to induce a systemic inflammatory response. DESIGN: Investigative study. SETTING: University-affiliated tertiary care hospital. PARTICIPANTS: Eight children (age range, 3 months to 13 years) undergoing CPB to correct congenital heart disease. INTERVENTIONS: The time courses of leptin and cortisol levels were determined. Serial blood samples were collected from the arterial catheter or from the CPB circuit preoperatively; on termination of CPB; and at 2, 4, 8, 12, 18, and 24 hours postoperatively. Plasma was recovered immediately, divided into aliquots, and frozen at -70 degrees C until use. Leptin was measured by a human leptin radioimmunoassay kit. MEASUREMENTS AND MAIN RESULTS: Leptin levels during CPB decreased to 50% of pre-CPB levels (p < 0.01). After termination of CPB, levels increased gradually and peaked at 12 hours postoperatively (10 P.M. to 1 A.M.). Cortisol levels were inversely correlated to leptin levels (p = 0.016). CONCLUSION: CPB is associated with acute changes in circulating leptin levels. These changes parallel those in cortisol, showing an inverse relationship between leptin and cortisol, suggesting a relationship between the neurobiology of these systems that could be important for the neuroendocrine response to CPB. A prognostic role of leptin and its relationship to cortisol after CPB warrant further study.

Serum leptin levels increase following acute myocardial infarction.

Leptin is secreted into the circulation and communicates the peripheral nutritional status to specific hypothalamic centers. Recent studies suggest that leptin may be involved in the acute response to stress, and that its interaction with the hypothalamo-pituitary-adrenal axis and the inflammatory cytokine system may be of clinical importance. Since these systems are activated during acute myocardial infarction (AMI), we studied leptin and cortisol levels during hospitalization in 30 consecutive patients admitted for AMI. The results show that leptin reached its peak on the second day of hospitalization, with a 2-fold increase from its baseline level on admission (p < 0.02). On day 3, leptin levels declined, and were 46%, 9%, and 6% above baseline on days 3, 4 and 5, respectively. The mean cortisol level was elevated on day 1 and decreased toward normal levels thereafter (p < 0.001). The cortisol level did not correlate with leptin concentration throughout the study. These findings suggest that leptin may have a role in the metabolic changes taking place during the first days after an AMI.

Circulating leptin and the perioperative neuroendocrinological stress response after pediatric cardiac surgery.

OBJECTIVE: Leptin may be involved in the acute stress response, regulating inflammatory parameters of major importance after cardiopulmonary bypass (CPB) surgery. Critically ill patients demonstrated significant increases in leptin levels in response to stress-related cytokines (tumor necrosis factor, interleukin [IL]-1) and abolishment of the circadian rhythm of leptin secretion. We characterized the pattern of leptin secretion in the acute postoperative period in children undergoing cardiac surgery and compared the changes in leptin levels with concomitantly occurring changes in cortisol levels, IL-8, and clinical parameters. DESIGN: Investigative study. SETTING: University-affiliated tertiary care hospital. PARTICIPANTS AND INTERVENTIONS: Twenty-nine consecutive patients, aged 6 days to 15 yrs, operated upon for the correction of congenital heart defects were studied. Surgery in 20 patients (group 1) involved conventional CPB techniques, and 9 (group 2) underwent closed-heart surgery. The time courses of leptin, cortisol, and IL-8 levels were determined. Serial blood samples were collected preoperatively, on termination of CPB, and at six time points postoperatively. Plasma was recovered immediately, aliquoted, and frozen at -70 degrees C until use. MEASUREMENTS AND MAIN RESULTS: The leptin levels in group 1 decreased during CPB to 51% of baseline (p <.001), then gradually increased, reaching 120% of baseline levels at 12-18 hrs postoperatively (p <.001), returning to baseline levels at 24 hrs (p <.01). In patients undergoing closed-heart surgery (group 2), leptin levels displayed a pattern resembling the first group: they decreased during surgery to 71% of baseline levels (p =.002) and showed a tendency to return to baseline thereafter. All group 1 patients' cortisol levels increased significantly during the first hour of surgery, then decreased, returning to baseline levels at 18-24 hrs postoperatively. There was a significant negative correlation between leptin and cortisol levels (r = -2.8, p <.01). In group 2, cortisol levels increased during and after surgery, peaking 4 hrs postoperatively and decreasing thereafter. IL-8 levels determined in 15 group 1 patients increased significantly during CPB, peaked at the end of surgery, and then decreased but remained slightly elevated even at 48 hrs postoperatively. There was a significant correlation between cortisol and IL-8 levels (r = 2.55, p <.05). Children with leukocytosis, tachycardia, and hypotension had lower leptin levels and less variation over time as opposed to those with an uncomplicated course. CONCLUSIONS: CPB is associated with acute changes in circulating leptin levels. These changes parallel those in cortisol, demonstrating an inverse relationship between leptin and cortisol. Further studies of the prognostic and therapeutic roles of leptin after CPB should be investigated.

Pregnancy and amyloidosis: II. Suppression of amyloidogenesis during pregnancy.

The observation of a deleterious effect of pregnancy on kidney function in amyloidosis of familial Mediterranean fever suggests that pregnancy may enhance amyloidogenesis. To determine whether pregnancy may indeed affect amyloidogenesis, pregnant mice were made amyloidotic by administration of amyloid-enhancing factor (AEF) and AgNO3 at different points in time from conception, and amyloid- deposition was studied with the crush-and-smear technique. A possible effect of exogenous female sex hormones (beta-estradiol and progesterone) on amyloidogenesis was studied by administration of these hormones during amyloid induction in nonpregnant female mice. Amyloidogenesis was found to be significantly suppressed in mice during pregnancy. The reduction was possibly related to the effect of pregnancy on the inflammatory stimulus (AgNO3) and not on the administered AEF. Exogenous estrogen and progesterone failed to inhibit amyloidogenesis in nonpregnant mice. These findings suggest that pregnancy may suppress amyloidogenesis in mice. The suppression is caused by an anti-inflammatory effect of pregnancy. Estrogen and progesterone are probably unrelated to this finding.

Thyroid function in attention deficit and hyperactivity disorder.

In view of the recent conflicting findings regarding the causative role of thyroid abnormalities in attention deficit hyperactivity disorder (ADHD), we performed a replication study to clarify the issue and establish clinical guidelines. Thyroid tests were performed in 43 ADHD children and 28 age- and gender-matched controls. Sixteen ADHD children showed total triiodothyronine (TT3) levels which were slightly above the upper limit of normal, but no significant difference in TT3 values was noted between the ADHD and the control groups. Moreover, none of the ADHD subjects had abnormal levels of total thyroxine, free thyroxine, thyroid stimulating hormone or total triiodothyronine reuptake. The present study supplies additional evidence for the lack of an association between thyroid function and ADHD, and counters the suggestion that thyroid function be routinely screened for in ADHD children.