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S Schatz

Publications and source records attributed to S Schatz.

13 recordsLinked to original sources
PubMed2001

Measurement of faecal cortisol metabolites in cats and dogs: a non-invasive method for evaluating adrenocortical function.

The aim of this comparative study was to gain more information about the metabolism and excretion of glucocorticoids in cats and dogs in order to establish non-invasive methods for evaluating stressful conditions. Therefore, in a first experiment, [14C]cortisol was administered intravenously to 8 animals (two of each sex and species). Over a period of 6 days, faeces and urine were collected immediately after spontaneous defecation and urination. Marked species differences were found, as cats mainly excreted cortisol in the faeces (82% +/- 4% of the total recovered radioactivity), whereas in dogs only a small portion was found there (23% +/- 4%). The highest urinary radioactivity was observed after 9 +/- 3 h in cats and 3 +/- 1 h in dogs. Peak concentrations in the faeces occurred after 22 +/- 6 h in cats and after 24 +/- 4 h in dogs. Most of the radioactivity was not extractable with diethyl ether, indicating that the metabolites excreted in urine and faeces were mainly of the conjugated or polar unconjugated types. This was confirmed by RP-HPLC, which also revealed marked differences between cats and dogs concerning the metabolites formed. In addition, the immunoreactivity of the metabolites was tested in cortisol, corticosterone and 11-oxoaetiocholanolone EIAs. The latter, measuring 11,17-dioxoandrostanes (11,17-DOA) detected the highest quantities of immunoreactive metabolites in cats, but not in dogs. In a second experiment, the adrenal cortex of both species was stimulated by ACTH and, three weeks later, suppressed by dexamethasone. In this study, only faeces were collected over a period of 7 days. In both species, inter-animal variability in the basal and maximal/minimal faecal cortisol metabolite concentrations and the time course was observed. The 11-oxoaetiocholanolone EIA in cats and the cortisol EIA in dogs proved best suited for monitoring changes in adrenocortical activity. ACTH injections resulted in an increase above baseline values of 355%, (median) in 11,17-DOA concentrations in cats and of 702% in the concentrations of cortisol equivalents in dogs by about 25 h and 22 h (median) after injection, respectively. Minimal concentrations after dexamethasone administration were about 17% in cats and 31% in dogs (in relation to baseline values) and were reached in 66 h and 72 h, respectively. It was concluded that measuring cortisol metabolites in faeces should be a useful non-invasive tool for monitoring stress in carnivores.

Adrenal Cortex↗
PubMed2001

Spectroscopic probing of the acid-base properties and photosensitization of a fluorinated phthalocyanine in organic solutions and liposomes.

A perfluorinated derivative of phthalocyanine was synthesized as the free base, hexadeca-(2,2,2-trifluoroethoxy) phthalocyanine (H2F48Pc), and as a zinc complex, hexadeca-(2,2,2-trifluoroethoxy)-phthalocyaninatozinc (ZnF48Pc), and their spectroscopic and photochemical properties were studied. The absorption bands are shifted bathochromically relative to simple phthalocyanines, exhibiting the longest wavelength band near 735 nm (H2F48Pc) and 705 (ZnF48Pc). The solvatochromism of both compounds was modeled by Reichardt's ET(30) parameter and Kamlet, Abboud and Taft multiparameter approach. The former, simpler, model was found to be adequate. We found that H2F48Pc undergoes unique basic and acidic titrations in organic solvents. These titration processes are accompanied by spectral changes that are explained on the basis of the chromophore's symmetry. Singular value decomposition was employed to resolve the spectra into the contributions of the species at various stages of protonation and to obtain the equilibrium constants. Nuclear magnetic resonance spectra (1H, 19F and 13C) for the free base were obtained in a tetrahydrofurand8 solution. The carbon spectrum, taken as a function of temperature, provided evidence for the presence of a tautomerization process, which switches the two internal hydrogens between the four central nitrogen atoms. As far as we know, this is the first report of the measurement of the free energy of activation for such process (delta G = 10.6-11.4 kcal mol-1 between 217 and 330 K) for a phthalocyanine, in solution. Like most other phthalocyanines these two compounds also act as photosensitizers and as generators of singlet molecular oxygen. The absolute quantum yields (phi delta) for ZnF48Pc was 0.58 +/- 0.01 in benzene and 0.35 +/- 0.01 in lipid vesicles. H2F48Pc had lower yields, 0.16 and 0.005, respectively. Either protonation or deprotonation of the pyrrole nitrogens in H2F48Pc lowered the phi delta.

Hydrogen-Ion Concentration↗
PubMed2001

[Effect of vaccination on fecal cortisol metabolites in cats and dogs].

The aim of this study was to apply a cortisol metabolite determination in the faeces of cats and dogs for monitoring disturbances. In this experiment faeces from every spontaneous defecation of 10 cats and 10 dogs (5 of each sex) were collected starting from one day before until two days after the yearly vaccination. Concentrations of 11,17-dioxoandrostanes (cat) and cortisol equivalents (dog) were determined by enzyme immunoassay (EIA). Faecal cortisol metabolites increased and reached peak concentrations (median: 412% in cats and 417% in dogs, respectively above baseline values) in one of the next two samples following the vaccination. This indicated an activation of the adrenocortex, the degree to which the different parts (physical and psychological components) of the whole vaccination procedure contributed to it was not evaluated. From this experiment we conclude that measuring cortisol metabolites in the faeces is a non-invasive method to monitor stressful conditions in cats and dogs and thus is a valuable tool for evaluating animal welfare.

Animals↗
PubMed2000

Post-streptococcal uveitis.

BACKGROUND: We report additional evidence supporting the association between the occurrence of bilateral nongranulomatous uveitis and previous infection by group A streptococci--i.e., post-streptococcal syndrome. METHODS: As shown through a series of case reports, physical examination and laboratory blood analysis--including antistreptolysin O (ASO) antibody titer--were ordered due to a recent history of sore throat and presence of nongranulomatous bilateral anterior uveitis. RESULTS: Serological laboratory testing revealed elevated ASO antibody titer. The etiology of the uveitis was attributed to streptococcal infection. Bilateral uveitis responded to topical corticosteroids. Systemic antibiotic treatment was used to treat possible post-streptococcal syndrome sequelae with resolution of symptoms. CONCLUSION: Uveitis should be considered a possible manifestation of post-streptococcal syndrome. ASO antibody quantification should be included in the serologic testing performed in evaluating the cause of seemingly idiopathic bilateral nongranulomatous anterior uveitis associated with signs and symptoms that suggest previous streptococcal infection.

Adolescent↗
PubMed1999

Effect of open and laparoscopic surgery on cellular immunity in a swine model.

Immune suppression associated with trauma has been demonstrated to be proportional to the magnitude of injury. Laparoscopic surgery has been shown to produce a diminished stress response compared to open surgery. Postoperative immune function, specifically cellular immunity, may be better preserved after laparoscopic surgery compared to open surgery. The aim of this study was to examine the effect of open versus laparoscopic surgery on cellular immunity in a swine model. Twenty domestic female pigs were randomly selected for laparoscopic cholecystectomy (LC) or open cholecystectomy (OC). Cellular immune functions were evaluated with delayed-type hypersensitivity (DTH) skin test and serial phytohemoagglutinin (PHA)-induced T-cell proliferation of the peripheral blood. There was a significant reduction in PHA-induced T-cell proliferation in both LC and OC groups on days 1 and 3 compared to preoperative values (p < 0.05). The reduction of mitogen-induced T-cell proliferation after LC was significantly less than after OC on day 1 (p = 0.03). The mean DTH reaction was 29.7 +/- 3.7 mm2 in the LC group compared to 13.9 +/- 1.2 mm2 in the OC group (p < 0.001). There was no difference in postoperative white blood count values between the two groups. Suppression of cellular immunity occurred after both LC and OC. The magnitude and duration of impaired cellular immunity after laparoscopic surgery was less than after open surgery as measured by T-cell proliferation and DTH response.

Animals↗
PubMed1998

Coagulation modifications after laparoscopic and open cholecystectomy in a swine model.

BACKGROUND: The stress response to surgical trauma precipitates a state of transient hypercoagulation. Studies have demonstrated that laparoscopic surgery results in a diminished stress response compared to open surgery. The aim of this study was to determine the extent of postoperative hypercoagulability following laparoscopic cholecystectomy (LC) compared to open cholecystectomy (OC). METHODS: Twenty-one pigs were randomly selected to undergo LC (N = 10) or OC (N = 11). Whole blood was collected preoperatively and on postoperative days (PODs) 1, 2, and 3 for determination of viscoelastic changes using a thromboelastography (TEG) coagulation analyzer. Four parameters were calculated from the TEG: R (reaction time), K (coagulation time), alpha (rate of clot formation), and MA (maximal amplitude). Antithrombin III (AT III) level was measured preoperatively and on POD 1. RESULTS: After OC, three of four TEG parameters changed to reflect a state of hypercoagulation. Only MA values were significantly changed after LC. Comparison between OC and LC showed no difference in the TEG parameter. There was no significant change in AT III levels after LC or OC. CONCLUSIONS: OC results in postoperative hypercoagulation typically encountered in open abdominal surgery. Although there were no differences in TEG or AT III between the two groups, after the laparoscopic approach all but one TEG parameter remained unchanged, suggesting a diminished hypercoagulable state. By reducing postoperative hypercoagulation, laparoscopic surgery may reduce the risk of developing postoperative venous thrombosis.

Animals↗
PubMed1996

Monoclonal B-cell population mimicking lymphoma in a patient with multiple sclerosis.

BACKGROUND: Diagnosis of intraparenchymal brain lesions has usually required invasive diagnostic procedures, because too few cells are shed into cerebrospinal fluid to permit cytologic diagnosis. Polymerase chain reaction technology makes it possible to identify cell populations that are present at a much lower frequency than traditional techniques. CASE REPORT: A young woman presented with multiple brain lesions raised the question of primary central nervous system lymphoma. Polymerase chain reaction analysis of cerebrospinal fluid showed evidence of a monoclonal B-cell population heightening suspicion of lymphoma. Brain biopsy showed acute demyelination most consistent with multiple sclerosis. CONCLUSION: Although T-cell restriction has been demonstrated in multiple sclerosis lesions, the finding of a monoclonal B-cell population was unexpected and to our knowledge has not been previously reported. This case emphasizes that monoclonality is not always indicative of a neoplastic process, particularly in the central nervous system.

Adult↗
PubMed1986

Congenital spleen thinning mimicking a space-occupying lesion.

By splenic imaging, a large focal defect was demonstrated in a symptomatic South American immigrant with simultaneous parasitic infestation of strongyloidiasis and entamebiasis. The CT scan also was thought to be abnormal. Pathologic findings reported a variation in splenic configuration. Unusual splenic configuration should be considered in the differential diagnosis of abnormal scans.

Adult↗