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Biomedical subjects

A Pfeffer

Publications and source records attributed to A Pfeffer.

At least 37 records · Page 2Linked to original sources
PubMed1995

Comparison of local and systemic responsiveness of lymphocytes in vitro to Bovicola ovis antigen and concanavalin A in B. ovis-infested and naive lambs.

The in vitro proliferation assay was used to determine lymphocyte responsiveness to soluble antigen of B. ovis and to Concanavalin A (Con A) in peripheral blood, spleen and various lymph nodes from B. ovis-infested and naive lambs. From March to July, an assay of monthly blood samples showed generally higher proliferative responses to antigen and Con A in B. ovis-infested than naive lambs. The proliferative response of cells from the skin-draining prescapular lymph nodes to B. ovis antigen was significantly higher in B. ovis-infested than naive lambs. Responses of cells from the medial iliac, mediastinal and mesenteric lymph nodes (which do not receive lymph from the skin) and spleen showed no significant differences between groups. Within the B. ovis-infested lambs, the response of cells from the prescapular lymph node was significantly higher than that from any other lymphoid organ examined. Responsiveness of the prescapular, medial iliac and mesenteric lymph node and spleen cells to Con A was not significantly different between groups, while mediastinal lymph node cells showed a significantly higher response in B. ovis-infested lambs. The data indicate that the antigen-specific cellular immune response is operating mainly locally, at the level of the skin and draining lymph nodes. Responses to the T cell mitogen Con A did not support non-specific immunodepression as reported in other ectoparasite/host systems.

Animals↗
PubMed1995

Effectiveness of BCG vaccination in protecting possums against bovine tuberculosis.

Three groups of eight possums were vaccinated with BCG Pasteur by the subcutaneous, intratracheal or intragastric routes, with a fourth group serving as unvaccinated controls. Forty-two days after the start of vaccination, five possums from each group were challenged intratracheally with virulent Mycobacterium bovis. The vaccination by the subcutaneous or intratracheal routes resulted in a marked reduction in the severity of disease compared with the unvaccinated animals or the animals vaccinated intragastrically. The severity of the disease was assessed by changes in bodyweight, pathological changes in the lungs and bronchial nodes and the number of acid-fast bacilli in the lesions. Before the challenge, lymphocyte blastogenic responses to bovine PPD were observed in the eight animals vaccinated subcutaneously and in two of the animals vaccinated intratracheally.

Animals↗
PubMed1995

Immunological responses and protection against Mycobacterium bovis in calves vaccinated with a low dose of BCG.

Groups of calves (20 per group) were vaccinated subcutaneously with a single dose of BCG Pasteur (6 x 10(4) or 6 x 10(6) colony forming units) and two months later, 15 calves from each group were challenged intratracheally with virulent Mycobacterium bovis. Vaccination with either dose of BCG induced significant protection against the development of tuberculous lesions compared to non-vaccinated controls. Seven months after BCG vaccination, many of the vaccinated animals which had no lesions and were M. bovis culture-negative at necropsy showed positive reactions for M. bovis in three assays for measuring cellular immune responses (comparative intradermal test, interferon-gamma assay and lymphocyte proliferation assay). This effect was most noticeable in the BCG-vaccinated calves which had been challenged with M. bovis rather than in the non-challenged animals. Antibody responses to M. bovis were very low or absent in the calves during the study. The kinetics of the interferon-gamma response of peripheral blood lymphocytes cultured in vitro with bovine PPD showed that BCG vaccination induced a rapid rise in the response followed by a sharp decline, while infection with virulent M. bovis resulted in an increase in the interferon-gamma response by four weeks after challenge and this response remained high through the study.

Animals↗
PubMed1995

Preliminary investigations into the aetiology and treatment of cockle, a sheep pelt defect.

A defect of sheep pelts known as cockle, detectable after depilation, but usually first noted only in the pickled pelt or tanned stage of processing, was studied to establish causal factor(s) and effective treatments. In addition, data on the histology and seasonal prevalence of the disease were obtained. Samples collected soon after slaughter from pelts identified at the pickled pelt stage as having cockle, had a superficial dermatitis with infiltration of eosinophils. This may represent an immediate hypersensitivity reaction of the sheep to lice. Treatments of sheep with either insecticides, disinfectants or shearing showed that where biting lice (Bovicola ovis) were removed, cockle lesions had either disappeared or regressed on pickled pelts. In Trial 1 diazinon reduced cockle prevalence and severity substantially; cypermethrin had a less pronounced effect. In Trial 2 diazinon, cypermethrin, Hibitane and Savlon were equally effective in reducing biting louse numbers as shown by counts of lice at 35 and 63 days post-treatment. Reduction of cockle on pelts from sheep slaughtered at 39 days post-treatment was achieved best by both diazinon and shearing. Examination of other pelts at 67 days post-treatment showed diazinon and Hibitane to be equally effective in reducing cockle. Furthermore, shearing in the absence of insecticides reduced the severity and extent of lesions on cockled pelts. The diazinon excipient and zinc sulphate were consistently poor at removing lice and reducing cockle prevalence and severity. The results have important implications for the leather industry in that shearing and good dipping practice with appropriate chemicals at the right time can lead to improved pelt quality. However, an incentive scheme for farmers, and a means of identifying individual pelts to the farms or origin, are both necessary before a marked improvement is likely to occur.

Animals↗
PubMed1995

Induction of an acute phase response in lambs causes an increase in plasma levels of GH and IGF-I.

GH and IGF-I plasma concentrations were measured in lambs during an acute phase response induced by an intrathoracic injection of yeast. The acute phase response was indicated by reduced feed intake, weight loss and an increase in plasma concentrations of the acute phase protein haptoglobin. Intensive blood sampling on day 1 revealed elevated basal concentrations of GH in the yeast-injected group compared with concentrations in pair weight and ad libitum fed control lambs. This suggests that at the beginning of an acute phase response there is an increase in either GH secretion or the half life of GH. No evidence of a specific GH-binding protein in sheep plasma could be detected. IGF-I concentrations in the yeast-injected group remained constant for 3 days then increased to a peak level at day 6. In contrast, plasma IGF-I concentrations were depressed from days 3 to 6 in the pair weight control group and they were unchanged in the ad libitum fed controls. When the IGF-I concentrations were elevated in the yeast-injected group, this group had a higher daily weight gain despite their lower feed intake compared with the ad libitum fed controls. These results suggest that IGF-I may be associated with the increase in weight in the late stage of an acute phase response during recovery from an infection or injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute-Phase Reaction↗
PubMed1994

Experimental Mycobacterium bovis infection in the brushtail possum (Trichosurus vulpecula): pathology, haematology and lymphocyte stimulation responses.

Groups of adult male brushtail possums (5 per group) were inoculated intratracheally with a high (2 x 10(5) colony forming units (cfu)), medium (2 x 10(3) cfu) or low (approximately 20 cfu) dose of Mycobacterium bovis. Two sham-inoculated groups acted as in-contact controls or controls kept in a separate room. Possums in the high and medium dose groups became clinically affected 3-5 weeks post-inoculation (PI) and all possums were euthanased between 5-9 weeks PI. Grossly visible tuberculous lesions were found in the lungs and associated lymph nodes of all possums from the high, medium and low dose groups. No lesions were observed in possums from the two control groups. Histopathologically, two characteristic types of lesions were observed; microscopic aggregates of macrophages with few acid-fast organisms, and larger lesions with limited granulomatous reaction, extensive necrosis and the presence of numerous acid-fast organisms. M. bovis was isolated from the lungs and lymph nodes of all of the possums from the high, medium and low dose groups and from the lungs of one of the in-contact controls. Changes in the haematological profile of the M. bovis-inoculated possums included lymphocytopaenia and eosinopaenia, together with raised fibrinogen levels. The onset of these changes was dependent on the size of the challenge dose. Lymphocyte stimulation responses to M. bovis tuberculin purified protein derivative were detected in 14 of 15 M. bovis-inoculated possums.

Animals↗
PubMed1994

Tuberculosis in the brushtail possum (Trichosurus vulpecula) after intratracheal inoculation with a low dose of Mycobacterium bovis.

Six possums were each inoculated with approximately 125 colony-forming units of Mycobacterium bovis via a cannula inserted per os into the trachea. Five other possums were sham inoculated and housed separately. At postmortem examination 55 to 57 days after inoculation, all six infected possums showed extensive macroscopical lesions of tuberculosis in the lungs and bronchial lymph nodes and some also had lesions in the liver, kidney, spleen and hepatic lymph nodes. Mycobacterium bovis was isolated from all of these possums. No evidence of M. bovis infection was detected in the five control animals. In the M. bovis-infected possums, microscopical examination of organs and lymph nodes demonstrated a much wider distribution of lesions than did macroscopical examination. The location of early lesions indicated that the paracortical region of the lymph nodes, the marginal zone and periphery of lymphoid follicles in the spleen, and the cortex of the kidney were predilection sites for lesions resulting from haematogenous spread of infection. This method for reproducing bovine tuberculosis in the possum was more suitable for experimental studies than previously published methods.

Animals↗
PubMed1994

[Level of vitamin B12 and folic acid in blood serum of patients with senile dementia].

85 cases over 65 were examined to establish concentration of B12 and folate acid in the serum. 25 cases of Alzheimer's Disease (AD), 33 patients with Multi Infarct Dementia (MID) and 27 non demented persons were collected. Folstein's Mini Mental State and Hachinski scales were chosen for the purpose of the study 2 AD case (8%) patients demonstrated lower concentration of B12. No improvement after treatment was observed, although normalization of vitamin B12 level was reached. In elderly control group as well as in MID patients B12 and folic acid level in serum was in normal range. Statistically significant negative correlation between B12 serum concentration and dementia in woman population with MID was noted.

Aged↗
PubMed1994

Immunochemical analysis of some proteins in cerebrospinal fluid and serum of patients with ischemic strokes.

Immunochemical studies of gamma gamma-neuron specific enolase (NSE), parvalbumin (PV), S-100 protein (S-100) and acidic fibrillary glial protein (GFAP) were studied in the cerebrospinal fluid and blood serum in 7 patients with ischemic cerebral stroke, aged 57 to 81 years. Cerebrospinal fluid and the first blood sample were taken on the first or second day of the disease. Further blood samples were taken once a week till the end of patients hospitalization, ending by patients discharge or death. Immunochemical identification of proteins under study were performed with Western-blotting technique. It was found that all proteins studied were present in both cerebrospinal fluid and blood serum on the first two days of the disease in small quantities. The blood content of both NSE and PV increased significantly during the first week of the disease. Both proteins disappeared from the blood serum between the second and fourth disease weeks. S-100 protein and GFAP contents in the blood reached significantly high level within the time interval between second and fifth disease weeks, and remained at a relatively high level till patients' death. In all cases computed tomography study and/or brain autopsy revealed extensive ischemic foci localized within areas supplied by the middle cerebral artery. No clear-cut correlation between extensiveness of the ischemic cerebral damage and the content of the proteins studied in both cerebrospinal fluid and blood serum was found. However, our data indicate that serial studies of the above proteins in patients with ischemic stroke may be useful in monitoring the progress of the disease, and occasionally in the prognosis at least in some cases.

Aged↗
PubMed1993

Acute phase protein response, food intake, liveweight change and lesions following intrathoracic injection of yeast in sheep.

Acute phase protein concentrations in blood, food intake and liveweight changes were compared in 10 sheep given intrathoracic injections of yeast and 10 control sheep over a period of 61 days. The yeast injections caused acute pleuritis and limited necrotising lung lesions which progressed to fibrous pleural adhesions and walled-off abscesses. The responses of ceruloplasmin, fibrinogen and haptoglobin were closely correlated (r = 0.87 to 0.91) in the yeast-injected sheep with peaks on days 5 or 7 after treatment (4, 4.6 and over 130 times control, respectively). Albumin concentration fell to a nadir of 89 per cent of control on day 12 after treatment. Depression of food intake was temporally related to the 'positive' acute phase protein responses with a nadir on day 5 after treatment (30 per cent of control). Liveweight showed a pronounced fall to five days after treatment and thereafter remained depressed relative to the controls for most of the experimental period. The data suggest that the 'positive' acute phase proteins may be useful indicators of production losses due to inflammatory diseases in sheep.

Acute-Phase Proteins↗
PubMed1989

Acute phase response of sheep: changes in the concentrations of ceruloplasmin, fibrinogen, haptoglobin and the major blood cell types associated with pulmonary damage.

The concentrations of plasma ceruloplasmin, plasma fibrinogen, serum haptoglobin and the major cell types in blood together with liveweight changes were monitored during the acute phase response in sheep. Five control sheep, five sheep that underwent sham bronchial obstruction, and five sheep that developed pneumonia after bronchial obstruction were examined. Blood samples were taken and liveweights were recorded from four to six days before until 14 days after the surgical operations (sham and bronchial obstruction). The operations led to an acute phase response in the sheep and the development of pneumonia increased and sustained the response or led to a secondary response. Statistically significant changes observed in the blood of the sheep during the acute phase response included increased concentrations of plasma ceruloplasmin and plasma fibrinogen, depression of erythrocyte numbers and elevation of neutrophil numbers (means on day of maximum change as percentage of pretreatment values; 250 per cent, 400 per cent, 80 per cent and 200 per cent, respectively). Serum haptoglobin showed a pronounced and significant increase in concentration (over 6000 per cent of pretreatment values in some sheep). All three groups of sheep showed significant depression of liveweight after overnight confinement in the surgery but this was sustained for the period of the experiment only in the bronchial obstruction group. The results indicated that measurement of the concentrations of the three plasma proteins may be more useful in the diagnosis of tissue injury and infectious disease than the number of circulating neutrophils in sheep.

Acute-Phase Proteins↗
PubMed1988

Pneumonia following experimental bronchial obstruction in sheep.

Five of 7 sheep in which the bronchi supplying the right apical lobe of the lung were obstructed with a cottonwool plug developed pneumonia. Large numbers of bacteria were isolated from 4 of the 5 pneumonic lungs. Only minor pulmonary lesions, which are common in sheep on pasture, were observed in 5 sham operation and 5 control sheep. These results support a role for airway obstruction in compromising the antimicrobial defences of the lungs in naturally occurring bacterial pneumonias of sheep.

Animals↗
PubMed1987

Effect of indomethacin on bombesin-like immunoreactivity, somatostatin and gastrin secretion from rat stomach.

In the present study the effect of indomethacin-induced prostaglandin deficiency was examined on the release of bombesin-like immunoreactivity (BLI), a putative peptidergic neurotransmitter, from the isolated perfused rat stomach. In addition, gastrin and somatostatin (SLI) secretion was determined. Pretreatment of rats with indomethacin (2 mg/kg X h) resulted in a 3-fold increase of basal BLI secretion. In response to acetylcholine (2 X 10(-6) M) BLI rose from 2,000 to 4,000 pg/min, whereas in controls BLI increased from 400 to 1,400 pg/min. While absolute values for BLI secretion were higher in indomethacin-treated stomachs the relative increase above baseline was lower (100 vs. 250%). In control rats the increase in BLI secretion in response to acetylcholine was abolished when the acidity in the gastric lumen was increased from pH 7 to pH 2. After indomethacin, however, the stimulatory effect of acetylcholine during luminal pH 7 and pH 2 was identical. The decrease of SLI by acetylcholine at luminal pH 7 was abolished in indomethacin-treated stomachs in response to 10(-6) M acetylcholine, and 2 X 10(-6) M had even a stimulatory effect on SLI secretion. Indomethacin pretreatment reduced gastrin secretion at luminal pH 7. These data demonstrate that endogenous prostaglandins exert an inhibitory tone on basal and stimulated BLI and stimulated SLI secretion in the rat stomach. It is suggested that endogenous prostaglandins also inhibit the release of a peptidergic neurotransmitter, similar to their effect on the classical neurotransmitters acetylcholine and norepinephrine.

Acetylcholine↗
PubMed1986

Effects of acetylsalicylic acid and indomethacin on single groups III and IV sensory units from acutely inflamed joints.

In cats with an acute experimental inflammation in the right knee joint the effects of acetylsalicylic acid (ASA) and indomethacin on the discharge properties of single fine myelinated and unmyelinated articular afferent units were tested. The knee joint was inflamed by injection of kaolin and carrageenan into the joint cavity some hours before the recording period. Before drug application the single afferent fibres showed resting activity and responses to movements of the joint within its working range which is common for units from the inflamed knee. Resting activity was reduced significantly in most units within 0.5 h after the intravenous injection of the drugs. Within the observation time of about 1-2 h there was no recovery. In a few units a transient increase of resting activity was observed immediately after the injection of a drug. After the initial observation period of 1-2 h the responses to movements were tested. They were reduced in all units except one myelinated afferent. Also during this testing period the resting discharges did not recover. Intra-arterial injection of prostaglandin E2 in low doses close to the joint temporarily nullified the depressing effects of aspirin and indomethacin. Resting activity and movement evoked responses were increased up to the level before the treatment with analgesic drugs. The effects of prostaglandin E2 lasted for several minutes to more than 1 h. The depression of resting and evoked activity in single afferent articular units from inflamed joints is discussed in relation to the analgesic properties of aspirin and indomethacin.

Afferent Pathways↗
PubMed1984

Modulation of acetylcholine-induced secretion of gastric bombesin-like immunoreactivity by cholinergic and histamine H2-receptors, somatostatin and intragastric pH.

Recently we have shown the release of bombesin-like immunoreactivity (BLI) from the isolated perfused rat stomach. In these experiments we have shown that BLI secretion is stimulated by acetylcholine. Gastric inhibitory peptide (GIP) exerts an inhibitory effect which is dependent on the intraluminal pH. The present study was designed to examine further the exact cholinergic mechanisms and to study the interaction between cholinergic and histaminergic mechanisms as well as the effect of the intraluminal pH. Acetylcholine elicited a dose-dependent increase in BLI and gastrin secretion (10(-6) M and 2 X 10(-6)M), whereas somatostatin release was suppressed at luminal pH 7. Blockade of muscarinic cholinergic receptors by atropine (10(-5)M) and nicotinic cholinergic receptors by hexamethonium (10(-5) M) abolished the effect of acetylcholine on all three peptides. Reduction of the intraluminal pH to 2 also abolished acetylcholine-induced stimulation of BLI and gastrin secretion and the inhibition of somatostatin secretion. Changes of intraluminal pH per se had no effect on the secretion of either peptide. Somatostatin (10(-7) M) reduced both BLI and gastrin secretion during stimulation with acetylcholine. The addition of the H2-receptor antagonist cimetidine (10(-5) M) abolished the effect of both doses of acetylcholine on BLI and somatostatin secretion and also the effect of the lower dose of acetylcholine (10(-6) M) on gastrin secretion during luminal pH 7. At luminal pH 2 cimetidine did not alter BLI and somatostatin secretion in response to acetylcholine, however, gastrin release was augmented in the presence of cimetidine. These data demonstrate that the effect of acetylcholine on BLI, gastrin, and somatostatin secretion is mediated by muscarinic and nicotinic cholinergic receptors and also by histamine H2-receptors. Somatostatin inhibits cholinergically induced BLI secretion. The cholinergic effects on BLI, somatostatin and gastrin secretion are abolished during an acidic intragastric pH. In this isolated perfused rat stomach model the inhibitory effect of intraluminal acid on gastrin secretion is, at least in part, mediated by H2-receptors. This suggests that the secretion of bombesin, a potential peptidergic neurotransmitter is modulated by neural, endocrine and local tissue factors and also by alterations of intragastric pH.

Acetylcholine↗
PubMed1977

Hermaphrodites in australian pigs. Occurrence and morphology in an abattoir survey.

In an abattoir study in Brisbane 19 hermaphrodites were found amongst 4000 pigs (0.475%). All pigs had female secondary genitalia with a tendency towards clitoridean enlargement and excessive erectile tissue below the vulva. The gonads had developed as testes, ovotestes or ovaries and were in the position of the ovaries in normal females. Ovaries were as in normal females, apart from a possibly higher incidence of cysts. Ovarian activity was reflected by the different cyclic stages of the normal uteri at the time of slaughter. In testes and ovotestes there was no spermatogenesis, but an increased proportion of interstitial cells of Leydig and a large amount of fat. It is estimated that in a herd of pigs about 1% of apparent females may be hermaphrodites, most of which are sterile. Economic loss may be caused if these animals are selected for breeding, apart from the possibility of other congenital abnormalities in herds with a high incidence of hermaphroditism. Tainting of meat products prepared from hermaphrodite pigs may also cause economic loss. It is pointed out that the phenotypic classification of hermaphrodites is of limited value and it is suggested that a pathogenetic classification should be established for domestic animals.

Abattoirs↗
PubMedDate not supplied

Frontotemporal dementia: An attempt at clinical characteristics.

The clinical recognition of frontotemporal dementia (FTD) depends on its differentiation from Alzheimer's disease (AD). From 212 patients primarily diagnosed as probable AD, 24 cases with mild dementia, absence of disturbances the presence of which would have prevented a full neuropsychological assessment, and brain CT with detailed visualization of hippocampus atrophy were chosen. On the basis of neuropsychological examination the patients were divided into two groups: 11 cases with predominant deficit in frontal system tasks (FTD group) and 13 cases with changes in cognitive functions typical of AD (AD group). Age at onset, duration, behavioral changes, psychotic symptoms, depression, speech disorders, neurologic deficit and hippocampal atrophy were analyzed in both groups. Statistically significant differences for behavioral disturbances and hippocampal atrophy were found. Early behavioral changes and lack of early hippocampal atrophy on CT may be useful features for differentiating between FTD and AD, especially when SPECT is not available.

Aged↗