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Biomedical subjects

M Philipp

Publications and source records attributed to M Philipp.

At least 109 records · Page 6Linked to original sources
PubMed1986

Biochemical and immunologic characterization of a major surface antigen of Dirofilaria immitis infective larvae.

A 35 kD major surface antigen of Dirofilaria immitis third-stage larvae was characterized biochemically and immunologically. Living larvae were iodinated by using Iodo-gen, iodosulfanilic acid, lactoperoxidase-glucose oxidase, and Bolton-Hunter reagents. Detergent extracts of larvae labeled by the first three methods showed one major 35 kD component and a number of smaller components of about 6 kD, as analyzed by one-dimensional SDS-PAGE. In contrast, extracts from larvae labeled with the Bolton-Hunter reagent showed multiple bands on gels. The 35kD molecule was shown to be exposed on the larval surface, insofar as it was accessible to trypsin-proteolysis on living radiolabeled larvae. Two-dimensional gel electrophoresis resolved the 35 kD band into two components: a major one with a pI of 3.8, and a minor one of pI 7.3. The lower m.w. bands were resolved into about 12 constituents with pI values from 3.5 to 8.0. Of all these surface molecules, the only one that was antigenic was the 35 kD component. It could be immunoprecipitated with sera from dogs carrying an occult experimental D. immitis infection or with sera from dogs immunized with irradiated third-stage larvae of this parasite. Similarly, sera from rabbits immunized repeatedly with normal unirradiated larvae also precipitated the 35 kD antigen. None of these sera, however, contained detectable antibodies to the surface-labeled low m.w. molecules. Sera from rabbits immunized with D. immitis adult worms and microfilariae precipitated the 35 kD antigen, which is therefore not stage specific. In contrast, sera from dogs experimentally infected with Toxocara canis and Ancylostoma caninum or with Uncinaria stenocephala (a canine hookworm) did not contain antibodies to the 35 kD antigen, but did cross-react with many other D. immitis adult and microfilarial antigens. This molecule may therefore be species specific. Evidence for glycosylation of the 35 kD molecule was not found: it did not bind to peanut, wheat germ, lentil, or Ulex europeus lectins, and its electrophoretic mobility was not altered after treatment with endoglycosidase-F or mild alkali solutions.

Animals↗
PubMed1986

Construct validity of the DSM-III and RDC classification of melancholia (endogenous depression).

Diagnostic schedules for any psychiatric disorder should represent a coherent concept and demonstrate adequate construct (internal) validity and transferability. Testing fit to latent class models (e.g. by Rasch model fitting test), correspondence to these requirements can be assessed. Based on data from a sample of 173 depressed in-patients, diagnostic schedules for endogenous depression (melancholia) according to DSM-III and RDC are evaluated for their ability to fit the requirements listed above. According to the data presented, the set of DSM-III-criteria for melancholia represents a coherent concept; on the contrary, this is not the case for RDC-criteria. Furthermore, application of the diagnostic algorithm applied to the defining criteria according to DSM-III has been justified; again, this was not the case for the diagnostic algorithm according to RDC. However, a simple linear diagnostic algorithm emerges from our data.

Adult↗
PubMed1986

Expression of cross-reactive surface antigens by microfilariae and adult worms of Brugia pahangi during infections in cats.

Microfilariae of Brugia pahangi were labelled with 125-Iodine using the reagent IODOGEN. Electron microscope autoradiographs of sections of iodinated microfilariae showed that the label was strictly confined to their sheath. Adult worms were also iodinated by the same procedure. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of detergent extracts of radio-labelled parasites revealed components of molecular weights 113, 81-71, 46 and 33 kDa in microfilariae, and of molecular weights 29, 20 and 16 kDa in adult worms. All but the 33 kDa component of microfilariae were immunoprecipitable with sera of infected cats and therefore antigenic. Antibodies to the 81-71 kDa and the 46 kDa microfilarial antigens were detected by immunoprecipitation before patency. Similarly, the 29 kDa antigen of adult worms was immunoprecipitable before the fourth moult. Therefore, during infection in cats, these antigens cross-react with epitopes present on earlier developmental stages.

Animals↗
PubMed1986

Psychopathological correlates of plasma cortisol after dexamethasone suppression: a polydiagnostic approach.

Seventy-seven consecutively admitted inpatients with depressive syndromes were examined with the Present State Examination and classified according to eight different operational diagnoses of endogenous depression. All patients received a 1.5 mg dexamethasone suppression test (DST). Sensitivity, specificity and the corrected predictive values of DST nonsuppression (50 or more ng/ml at 0800 hr, 1600 hr, or 2300 hr), adjusted to a 50% prevalence of endogenous and nonendogenous depression, varied considerably depending on the diagnostic definition used. The highest predictive value (89.9%) was found with the Taylor-Abrams criteria (sensitivity = 43.9%, specificity = 95.0%), and the lowest predictive value (53.3%) with DSM-III (sensitivity = 37.7%, specificity = 68.1%). Eliminating the patients with dexamethasone levels of less than 2000 pg/ml improved the diagnostic specificity of the DST for most of the eight definitions of endogenous depression. This further indicates that plasma dexamethasone levels should be analyzed in studies designed to explore the diagnostic utility of the DST. A significant, chance-corrected association between DST nonsuppression and the diagnosis of endogenous depression was found with clinical diagnosis (according to the International Classification of Diseases), and for four out of eight operational diagnoses (Newcastle Scale I, Newcastle Scale II, Taylor-Abrams Criteria, and Vienna Research Criteria). For the other diagnoses (Research Diagnostic Criteria, DSM-III, Michigan Discriminant Index, and Hamilton Endogenomorphy Index), no significant association was found. The RDC criterion "early or intermittent awakening" was the only one out of 28 diagnostic criteria tested which was significantly associated with DST nonsuppression.

Adult↗
PubMed1986

The relevance of categorical and dimensional classification systems for the comparability of patient samples in psychopharmacological research of depression.

Operational diagnoses of endogenous depression have gained special importance for psychopharmacological research. The high reliability of operationally defined diagnoses is a prerequisite for sampling comparable patient group. The simultaneous application of competing categorical diagnostic system ("polydiagnosis") allows us to determine whether differences in research findings are due to differences in patient samplings. Furthermore, a dimensional classification of patients by means of a newly developed polydiagnostic scale (so called OPD scale) allows us to compare the diagnostic homogeneity of patient groups diagnosed as endogenous depression cases and to select extreme groups with high diagnostic homogeneity for comparing the distribution of variables under research in patients with endogenous and nonendogenous depression.

Depressive Disorder↗
PubMed1986

Compatibility between ICD-9 and DSM-III classification of endogenous depression (melancholia).

The classification of depressive disorders (subtypes of Major Depressive Episode--MDE) according to DSM-III is different in many respects from the classification according to ICD-9; the relevance of both diagnostic systems necessitates the assessment of their compatibility. In a sample of 173 depressed inpatients, both diagnostic systems are applied independently and the relationship between affective psychosis (endogenous depression) (ICD-9) and subtypes of MDE (DSM-III) is investigated. The resulting low rate of agreement between endogenous depression (ICD-9) and MDE with melancholia (DSM-III) can be improved considerably by a modification of the diagnostic algorithms applied in DSM-III. Furthermore, by combining the subtype or criteria of melancholia (DSM-III) and characteristics of course (recurrence, bipolarity) the ICD-9 diagnosis of endogenous depression can be simulated.

Adult↗
PubMed1986

A polydiagnostic scale for dimensional classification of endogenous depression. Derivation and validation.

Several operational diagnoses (OPD) for endogenous depression have been proposed. However--though aiming at similar clinical concepts--the amount of association and agreement between different OPD is rather low. In this study the relationship between eight OPD (Research Diagnostic Criteria, DSM-III, Michigan Discrimination Index, Newcastle Scale I, Newcastle Scale II, Taylor-Abrams Criteria, Vienna Research Criteria, Hamilton Endogenomorphy Index) was assessed by applying latent trait analyses to the classificatory data of these eight OPD which were rated simultaneously in a sample of 173 depressive inpatients. According to these analyses six OPD (RDC, DSM-III, NCS-I, NCS-II, TAC and VRC) are tapping the same phenomenon. This latent trait represents compatible concepts of endogenous depression; it is strongly associated with the independently assessed clinical ICD-9 diagnosis of endogenous depression. The six OPD can be considered as items of a scale (so-called OPD-scale). The total scores of the OPD-scale represent a dimensional assessment of the decisiveness of the diagnosis endogenous depression. Coefficients and parameters of this new scale are presented.

Adjustment Disorders↗
PubMed1986

The polydiagnostic interview: a structured interview for the polydiagnostic classification of psychiatric patients.

A structured interview (PODI) for the polydiagnostic evaluation of affective and schizophrenic disorders is presented. The interview includes elements of the Structured Clinical Interview for DSM-III (SCID) and of the Present State Examination (PSE). The central idea of this interview is to break down complex criteria into their elements, to assess a wide area of such elements, and to recombine them by a computer program according to different algorithms that are included in a greater number of operational diagnoses. Reliability data will be presented which show sufficiently high kappa and Yule coefficients for a selected set of diagnostic criteria for depressive, manic and psychotic disorders. The applicability of the PODI was established in about 180 interviews.

Diagnosis, Differential↗
PubMed1986

Methodological problems in polydiagnostic research.

The growing application of the polydiagnostic approach makes it necessary to examine the methodological problems associated with the simultaneous assessment of multiple competing diagnoses. This paper contrasts the method of nonstandardized consecutive judgement of nonintegrated criteria lists with the method of a structured polydiagnostic interview with integrated criteria lists. The comparison of two polydiagnostic studies using both methods of assessment confirms that the unstructured use of nonintegrated and consecutively judged criteria lists is biased by a halo effect. This halo effect leads to a reduction of differences between the classifications of competing operational diagnoses and influences the type of patient distribution along the diagnostic dimension. This finding is interpreted as an argument to switch over to integrated criteria lists applied on the basis of an unstructured clinical examination or a structured interview.

Diagnosis, Differential↗
PubMed1986

Dimensional assessment of endogenous depression based on a polydiagnostic approach.

A dimensional classification according to the decisiveness of the diagnosis of endogenous depression is proposed, based on a polydiagnostic approach using latent-trait models (Rasch model). The instrument is derived from a sample of 130 depressed patients, and a cross-validation of this instrument is reported in a sample of 87 patients with major depressive episode. The utility of this scale in biological research is discussed.

Depressive Disorder↗
PubMed1985

[Dimensions of the Hamilton Depression Scale. Factor analysis studies].

The results of factor analysis of HAMD are not unitary. Studying the stability in course and the independence of selection criteria for the population we rated two groups (n = 107, n = 98) of inpatients with HAMD; these groups differ in nosological selection criteria. We furthermore rated one group at different timepoints (before treatment and 3 weeks after). The one-factor-solution is the only stable one and the only one which is independent from selection criteria. In all groups the one-factor-solutions show a high similarity with other published solutions of the German version of HAMD. But there is no way to extract a general factor. Thus the ability of HAMD in judging the severity of depression is doubtful. Ways are discussed to circumvent this problem.

Adult↗
PubMed1985

Comparative analysis of observer depression scales.

The Hamilton Depression Scale (HAMD), Bech Rafaelsen Melancholia Scale (BRMS) and Montgomery Asberg Depression Rating Scale (MADRS) are analyzed according to mean discriminatory power, internal consistency, homogeneity and transferability. The analysis was done separately in different samples of patients with depressive syndromes: a) operationally defined depressive syndrome; b) Major Depressive Disorder (RDC); c) Major Depressive Disorder, endogenous type (RDC). BRMS and MADRS were superior to HAMD in all evaluated aspects. Further, the BRMS was superior to MADRS according to the criteria of homogeneity and transferability.

Adult↗
PubMed1985

Operational diagnosis of endogenous depression. II. Comparison of 8 different operational diagnoses.

The comparison of 8 different operational diagnoses (OPD) of endogenous depression in a group of 173 inpatients with operationally diagnosed depressive syndromes shows a rather low agreement between the different diagnoses. Whereas in most comparisons there is a significant association between the different diagnoses (chi 2) the chance-corrected agreement is poor (kappa less than 0.50) in nearly all comparisons. These values cannot guarantee a comparability of results found in patient samples which are diagnosed as endogenous depressions by different OPD. The simultaneous application of competing OPD (polydiagnosis) seems to be an approach suited to overcome this problem and allow comparability of research results of endogenously depressed patient samples.

Adjustment Disorders↗