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Biomedical subjects

E Gruys

Publications and source records attributed to E Gruys.

At least 127 records · Page 7Linked to original sources

[Endocarditis and meat inspection in slaughtering pigs. 2. Various aspects of meat inspection].

The results of meat inspection in 599 slaughtered pigs with endocarditis were studied. Of the pigs examined, 65 per cent were condemned. Condemnation was based on a positive bacteriological examination (Article 2 of the Meat Inspection Regulations) in almost every case. When bacteriological examination was negative, the animal was passed unqualified in nearly every case, regardless of the fact that symptoms were or were not detected in ante-mortem inspection and whether or not signs of sepsis were observed. Subsequently, efforts were made to determine the possible effects of omitting incisions into the hearts of pigs in which neither clinical nor morbid-anatomical examination suggested the presence of endocarditis. It was concluded that endocarditis would have passed unnoticed in 25 per cent of the pigs examined in this case. Of these pigs, fifty per cent were found to be positive on bacteriological examination. Finally, the financial consequences of condemning all pigs showing endocarditis were examined. Compared with current practice in meat inspection, this would result in an annual loss of Dfl. 60,000 in the situation prevailing in the Netherlands. However, if Articles 13, 17 and 18 of the Meat Inspection Regulations were strictly observed, the yield of the pigs passed would not offset the costs of examination.

Animals↗

[Iatrogenic mastitis in sheep].

Cases of ovine mastitis due to the use of dry-cow injectors are reported by the present authors. The inflammatory lesions were characterised by necrosis of mammary tissues, metaplasia of the epithelium of minor ducts and the appearance of macrophages and foreign-body giant cells. This is believed to have been caused by a mineral oil in an ointment base which was part of the material injected. However, injection of a different formulation using paraffin phenol also induced slight inflammatory lesions. Infection with maedi could not be ruled out in these cases. When drying off sheep is carried out as a routine procedure, it is recommended to refrain from using dry-cow injectors. Flocks in which there is a high incidence of mastitis require another, adapted approach.

Animals↗

[Polyarteritis nodosa].

With reference to sixteen cases of polyarteritis nodosa (seven dogs, two cats, two goats, three pigs, two cattle), current views regarding classification, aetiology and pathogenesis of this disease are discussed. Polyartertis nodosa is not a disease entity, but rather a symptom that may be associated with various forms of disease and may vary in pathogenesis. The clinical picture depends upon the localisation of the vasculitis. Toxic agents and various viruses may be directly responsible for the vascular lesions. In addition, genetic, autoimmune and allergic factors may be implicated. The immunological pathogenesis is illustrated with reference to the serum sickness model.

Animals↗

Augmentation of natural cell activity in tumor-bearing and normal mice by MVE-2.

Mice bearing advanced Lewis lung carcinoma were found to have significantly decreased natural killer (NK) cell activity in spleen and blood. The same pattern of lowered spontaneous NK cell activity was observed in nude mice with advanced human colon carcinoma LS 174 and in C3H mammary tumor virus-positive mice that spontaneously developed mammary adenocarcinomas. Maleic anhydride divinyl ether (MVE-2) usually augments NK cell activity in normal mice. We found that the lower level of spontaneous NK cell activity in tumor-bearing mice could be boosted by a single injection of MVE-2; however, this response was much weaker than that observed in age-matched normal mice. Multiple treatments with MVE-2 which are known to induce hyporesponsiveness to further augmentation of NK cell activity in spleen and blood of normal mice, also produced NK cell hyporesponsiveness in the spleen, bone marrow, and blood of tumor-bearing mice.

Adjuvants, Immunologic↗

The serum amyloid A stimulating factor (SAASF) in the hamster.

The acute phase SAA response was studied in hamsters. An SAA-stimulating factor (SAASF) was detected in the early acute phase blood plasma of hamsters which were subcutaneously injected with casein-LPS. The latter is routinely used in our laboratory for amyloid induction in hamsters. Acute (4 h) inflammatory exudates (greater than 80 per cent polymorphonuclear leukocytes) were produced by intraperitoneal injection with either casein-LPS, latex or Freund's incomplete adjuvant. Chronic inflammatory exudate macrophages (greater than 98 per cent) were elicited by intraperitoneal injection with Bacillus Calmette Guérin (BCG). Cells were stimulated in vitro with latex. SAASF was detected in the supernates and lysates of the acute exudate cells but not in those of the chronic peritoneal exudate macrophages. Lymphocyte activating factor (LAF), however, was evidently present in the latter samples, indicating that SAASF and LAF (IL-1) are functionally different substances in hamsters.

Animals↗

Proteinuria in the dog: a pathomorphological study of 51 proteinuric dogs.

Renal cortical biopsies of 51 dogs with spontaneous proteinuria were examined by histology, electron microscopy and immunofluorescence. Glomerular lesions were classified in four groups: mesangioproliferative, membranoproliferative and membranous glomerulonephritis and amyloidosis. The glomerular and the tubulointerstitial lesions were graded, using a semiquantitative system. The results were used for the calculation of correlation coefficients between several parameters. A positive correlation was found between the severity of glomerular and tubulointerstitial lesions. Fibrin detection by immunofluorescence and histochemical methods appeared not to be correlated. The presence of electron dense deposits correlated only with the fluorescence for IgG and C3. Fluorescence for IgA and IgM was frequently observed in cases with or without dense deposits.

Animals↗

Cell regulatory and immunorestorative activity of picibanil (OK432).

Picibanil (OK432), a pharmaceutical preparation of a low virulent Su strain of Streptococcus pyogenes, possesses cell regulatory activity particularly in its ability to augment natural killer (NK) cell activity and to activate macrophages to exert a tumoricidal effect both in vitro and in vivo. It is effective in retarding and/or inhibiting the growth of three different tumors: MBL-2 lymphoma, M109 alveolar adenocarcinoma, and B16 melanoma. The antitumor effect is mediated through regulation of NK cells and macrophages, possibly by its ability to stimulate the production and secretion of interferon and interleukin 1 and 2. It is a very effective adjuvant for tumor cell vaccines that elicit cytotoxic T-cell responses. Following cytoreductive chemotherapy (Cytoxan) Picibanil treatment leads to an earlier reconstitution of both bone marrow cellularity and differentiation to granulocyte-macrophage colonies.

Animals↗

Enhancement of amyloid induction by amyloid fibril fragments in hamster.

An extract (fibril amyloid-enhancing factor) prepared by sonication of a suspension of water-purified hamster AA-amyloid fibrils showed an amyloid-enhancing effect upon intraperitoneal injection into hamsters. The fibril amyloid-enhancing factor was identical to the original fibrils according to the results of infrared spectroscopy, gel filtration, gel electrophoresis, and Western blotting; although lyophilized samples of the extract did not show any green birefringence after staining with Congo red. From these results, it was concluded that fibril amyloid-enhancing factor represents small fragments of amyloid fibrils which enhance in vivo formation of amyloid fibrils.

Amyloid↗

C-reactive protein in dogs.

Serum concentrations of C-reactive protein (CRP) in dogs with various diseases or undergoing various procedures were measured by specific immunoassay. In 20 healthy dogs from various sources, values were all less than 5 mg/L, but in 22 healthy dogs from a single source, values ranged from less than 5 mg/L in 14 dogs and from 8 to 67 mg/L in 8 dogs. Increased concentrations of serum CRP were attained 24 hours after injection of casein (n = 9; median 188 mg/L), ovariohysterectomy (n = 11; median, 144 mg/L), or elective, nonacute orthopedic surgery (n = 10; median, 83 mg/L). After inoculation of Leptospira interrogans serovar canicola (n = 5), the behavior of serum CRP as an acute-phase reactant provided a sensitive and precise objective reflection of in vivo response. The CRP concentration in random single-serum samples from 73 dogs with other inflammatory and noninflammatory disorders ranged from normal (less than 5 mg/L) to 246 mg/L and generally correlated with the extent and activity of disease.

Animals↗

Diagnosis of the type of amyloid in paraffin wax embedded tissue sections using antisera against human and animal amyloid proteins.

Different histochemical techniques were compared on paraffin wax embedded tissue sections for routine classification of amyloid; the following methods were used: potassium permanganate, the indirect immunoperoxidase method using polyclonal anti-human amyloid antisera (anti-AA, anti-A lambda, anti-A kappa and anti-AF) and the peroxidase-antiperoxidase (PAP) method using antisera against human, bovine, hamster and canine AA amyloid. Anti-human AA antiserum appeared to be a useful tool in this respect. Polyclonal anti-AL antisera may be helpful in diagnosing AL amyloid, but were less of value than anti-AA serum. Strong cross reactivity between anti-bovine AA antiserum and human AA amyloid deposits was found. This indicates that animal amyloid AA antisera can also be used for the diagnosis of AA amyloid in human tissues.

Adult↗

Amyloid-enhancing factor (AEF) in the pathogenesis of AA-amyloidosis in the hamster.

AA-amyloidosis was induced in hamsters receiving amyloid-enhancing factor (AEF) by daily subcutaneous injection with either an aged casein solution or casein supplemented with lipopolysaccharide (LPS). Both amyloid inducers gave similar results with respect to amyloid development in spleen, liver and kidneys and to serum amyloid A (SAA) concentrations and plasma cathepsin D activities. AEF was isolated from amyloid-containing tissue by the method described by Hol et al. (1985), and amyloid-enhancing material was also extracted from isolated hamster amyloid fibrils by intensive sonification. This fibril-derived amyloid-enhancing material lacked typical green birefringence after staining with Congo red and appeared as amorphous material on electron microscopy. AEF shortened the pre-amyloid phase for splenic and hepatic amyloid development and also the subsequent interval before renal amyloid deposition. This indicates that endogenous AEF, unlike passively transferred preformed AEF, is not distributed throughout the body and is probably generated at the site of amyloid deposition. Moreover, these results suggest that amyloid deposition in the kidneys, like that in the spleen and liver, involves an AEF-dependent pathway. Thus redistribution of amyloid is probably not an important cause of renal amyloid involvement. In addition to the reduction in the lag phase for splenic and hepatic amyloid deposition, AEF also speeds the changes in SAA concentration and plasma cathepsin D activity. This indicates that AEF accelerates rather than eliminates the pre-amyloid phase.

Amyloidosis↗

Delayed swayback in goat kids, a study of 23 cases.

The results of a retrospective study of 23 goat kids with delayed swayback are reported. Principal clinical signs were ataxia, loss of postural control, spasticity of the hindlimbs, and muscular weakness, often progressing to permanent recumbency. Denervation of skeletal muscles was demonstrated by electromyography in 2 kids. Three kids slowly recovered during hospitalisation. Histopathological changes were characterized by degeneration of selected neuronal populations with their processes within the central and the peripheral nervous system. Affected systems included upper motor neuron, vestibular, general proprioceptive, and lower motor neuron pathways, with additional involvement of the cerebellar cortex in some animals. Our findings, including limited ultrastructural observations, support the notion that the neuraxon rather than the myelin sheath is the prime target of disease in delayed swayback. The available copper values of affected kids and their unaffected herd mates were significantly lower than those of random control goats, which provides further support for a role of copper deficiency in the aetiology of this disease in the goat.

Animals↗

Biological response modifiers: regulators of the cellular immune system and adjuvants in antitumor therapy.

Pharmacokinetic studies of five biological response modifiers (BRMs) show diverse regulator functions on effector cell responses and a capacity to cause the secretion of specific soluble factors. Of the five BRMs tested, MVE-2, Poly ICLC, OK-432, and alpha beta IFN were capable of stimulating both natural killer (NK) cell and macrophage (M phi) tumoricidal activity, whereas BM 41-332 augmented only NK cells. Following one treatment with the aforementioned BRMs, M phi activity remained elevated for a longer period (10-14 days) than did NK cell activity (6-9 days). Of particular interest, multiple treatment with BRMs led to a downregulation of NK cell activity (hyporesponsiveness). Three soluble secretory products were induced by these BRMs (colony stimulating factor, CSF; prostaglandin E, PGE; and interferon, IFN). Treatment with MVE-2 and Poly ICLC led to a significant increase in bone marrow cellularity and GM-CFV-C. Results of studies with the cyclo-oxygense-inhibited indomethacin indicate that CSF and PGE are produced and/or secreted by different cellular mechanisms. The depression of effector cells (NK, bone marrow, and GM-CFU-C), as the result of cyto-reductive treatment with cyclophosphamide, could be reversed by treatment with MVE-2. A significantly earlier time to recovery of these effector cells was achieved following MVE-treatment. When MVE-2 was used as an adjuvant to initial tumor cyto-reductive chemotherapy, more successful antitumor response was achieved, indicating that MVE-2 functioned to elevate a substantial effector cell response as well as reconstituting bone marrow cellularity.

Adjuvants, Immunologic↗

Proteinuria in the dog: a clinicopathological study in 51 proteinuric dogs.

In 51 dogs with predominantly massive urinary protein loss, the daily loss was quantified and glomerular and tubulointerstitial lesions from renal biopsies were characterised and graded using histology, immune fluorescence and electron microscopy. The highest median daily urinary protein loss occurred in dogs with membranous glomerulonephritis (median 380 mg kg-1 d-1) and renal amyloidosis (median 257 mg kg-1 d-1). Although in nine febrile dogs the urinary protein loss was transient, both glomerular and tubular lesions were diagnosed in five and seven of these dogs, respectively. The pattern of urinary proteins was determined using sodium dodecyl-sulphate polyacrylamide gel electrophoresis. The albumin fractional clearance (FC) was raised in 46 dogs, whereas the FCS of the low molecular weight (MW) protein fraction (MW less than 66,000) and high molecular weight protein fraction (MW more than 66,000) were raised in 42 and 28 dogs, respectively. Both the high molecular weight protein FC and albumin FC significantly correlated to the grade of glomerular lesions, whereas the low molecular weight protein FC only moderately significantly correlated to the grade of tubular lesions. The selectivity index, calculated as (formula; see text) did not differentiate between the various forms of glomerulopathies. The urinary lysozyme concentration was significantly correlated to the grade of tubular lesions. It is concluded that although quantitative and qualitative measurements of urinary proteins can provide additional clinical information, they do not have a reliable predictive value and histopathological examination of renal tissue is still necessary for the final diagnosis.

Animals↗

Effects of protein depletion on NK cell cytotoxicity and bone marrow cellularity.

Tumor bearing patients have repeatedly been shown to develop states of protein (PD). PD has frequently been associated with depression of acquired immunity. In contrast, little is known about the effects of PD on natural killer (NK) cell cytotoxicity and on bone marrow cellularity and how modulation of these parameters by maleic anhydride divinyl ether copolymer (MVE-2) would be affected. BALB/c mice 6-10 weeks old were fed normal diets (18% protein) (ND mice) or protein deficient isocaloric diets (PD mice) for 35 days. On days 5, 9, 15, 23, and 35 assays were performed. Three days prior to each assay day, some groups received MVE-2 i.p. In PD mice spontaneous NK activity was reduced by some 80%. After MVE-2 the levels only rose to half the amount of activity of ND mice, although in both groups an increase of NK activity took place. BMC levels of PD mice were also strongly decreased. After MVE-2, increases of BMC in PD mice were quite weak and did not reach the level of normal unstimulated BMC. In PD mice we found body weight loss of 46%, reduction in albumin and total protein of 22% and complete disappearance of prealbumin after 5 days of diets. Preliminary results indicate that repletion with amino acids (NeoAminomel L12.5 o.K.H. Salvia, Boehringer Mannheim Co.) is able restore NK activities and BMC levels.

Animals↗

Amyloid in canine mammary tumors.

In canine mammary carcinomas, amyloid was present as amyloid-containing corpora amylacea and as local deposits between neoplastic epithelial cells or in stromal tissue. Histochemical staining methods revealed that this amyloid was not of the AA-type amyloid and contained tryptophan. The possible pathogenesis of this amyloid deposition is discussed.

Adenocarcinoma↗

Activities of lysosomal enzymes and levels of serum amyloid A (SAA) in blood plasma of hamsters during casein induction of AA-amyloidosis.

Casein-induced amyloidosis in hamsters was found to be of the AA-type, as shown by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis of the major low-molecular weight component of the amyloid fibrils. Levels of serum amyloid A (SAA) and the activities of cathepsin D, beta-N-glucosaminidase, serine esterase, lactate dehydrogenase (LDH) and gamma glutamyl transpeptidase (GGT) were measured in the blood plasma during induction of amyloidosis. During the pre-amyloid phase an increase was observed in all these parameters. During the deposition of amyloid, an increase was observed in the activities of the lysosomal enzymes cathepsin D and beta-N-glucosaminidase, which was significantly correlated with amyloid deposition. Serine esterase activities did not show any relationship to amyloid deposition. LDH and GGT activities were normal in the amyloid phase. SAA levels were lower during amyloid deposition than during the pre-amyloid phase. These findings indicate that a specific release of lysosomal contents from mononuclear phagocytic cells is involved in the pathogenesis of AA-amyloidosis. Amyloid deposition may be the result of: (i) extrusion of intralysosomal protein AA or pre-amyloid, followed by extracellular formation of amyloid fibrils; (ii) secretion of lysosomal enzymes, followed by extracellular cleavage of SAA and subsequent aggregation of protein AA with other components.

Amino Acids↗