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Results for “Analysis of Variance”

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At least 595 records · Page 33Linked to original sources
PubMed1989

[Intensive immunosuppression in progressive multiple sclerosis. An open study comparing 3 groups: cyclophosphamide, cyclophosphamide-plasmapheresis and control subjects. Results after 3 years].

Three groups of 10 patients each with multiple sclerosis (MS) in a progressive phase were openly matched on the basis of age and invalidity (DSS Kurtzke). Variance analysis showed no significant difference between them for the main MS features. Group 1 received cyclophosphamide for 3 weeks (mean total dose: 152 mg/kg) with methylprednisolone (mean total dose: 2.77 g). Group 2 had a mean number of 9 plasma exchanges prior to a cyclophosphamide-methylprednisolone regimen similar to Group 1 (mean total dose of cyclophosphamide: 160 mg/kg and of methylprednisolone: 3.16 g). Group 3 was made up of controls. At three years, the proportion of stabilized and improved cases was 6/10 in group 1, 9/10 in Group 2 (statistically significant when compared with Group 1), and 0/10 in Group 3. The study of the variations of invalidity (DSS gains) showed a clear significant benefit in the treated groups when compared to controls, but no difference between the treated groups. Longitudinal studies showed that the mean therapeutic benefit was about 2.5 years. The role of cyclophosphamide and of plasma exchanges in these results is discussed.

Analysis of Variance↗
PubMed1986

[The effect of a weak magnetic alternating field on immunobiologic reactions].

UNLABELLED: The influence of a 10 Hz, 0.5 mT (millitesla) alternating magnetic field (rectangular function) on immunologic parameters was investigated. In four chambers, each containing 15 mice, the following electroclimatic conditions existed: conventionally air conditioned laboratory (L), screening of the ambient atmospheric electric fields (F), Faradayscreening plus the above mentioned magnetic field (F + M) and the magnetic field only (M). After 14 days of acclimatizing without magnetic field influence the mice were exposed to the field in the chambers F + M and M for 1, 3, 7 and 21 days, respectively. At the end of the exposure immunological reactions were examined. METHODS: Plaquetest (hemolysis in gel) according to Jerne et al. and determination of the hemagglutination titer. The different groups (L, F, F + M and M) were compared using the Student-t test or variance analysis. RESULTS: After 7 days of field exposure the plaquecount and the hemagglutination titer (converted into the logarithm of base 2) increased significantly in comparison to the controls (L and F, respectively) in some experiments. In experiments carried out with 3 and 21 days of exposure the same tendency (increase of immunological reaction) was detected.

Analysis of Variance↗
PubMed1988

[Multicenter study of the sensitivity to beta-lactam antibiotics of 1,707 strains of Pseudomonas aeruginosa isolated at a general hospital].

1,707 non replicate clinical strains of Pseudomonas aeruginosa from non teaching hospitals were investigated. Beta-lactam antibiotics were tested by agar disk diffusion method. Variance analysis revealed a significant interaction between strains and experimental laboratories. The bacterial population was grouped according to the diameters of inhibition zones of antibiogram, into five phenotypes. Pseudomonas aeruginosa is frequently isolated from urines and pulmonary sampling, rarely from blood cultures. Resistance to beta-lactams increased significantly with the duration of hospitalisation, and age of patients. Clinical strains are significantly more resistant in blood cultures, and for strains isolated from reanimation. 84% of strains are susceptible to ticarcillin.

Adolescent↗
PubMed1987

[Quality control of multicenter evaluation studies of the in vitro activity of antibiotics].

The estimation of the in vitro activity of an antibiotic, by different laboratories, requires the measurement, in standardized conditions, of the inhibition zone diameters versus a series of strains distributed to these laboratories (kits). Using the studies realized with two antibiotics, denoted by A and B, we observed an important variability between the different laboratories for a given strain and a less but still significant variability within the laboratories. Variance analysis revealed a significant interaction between strains and experimental laboratories. These results prevent the establishment of a standard diameter for a given strain but permit the quality control of the measurements and the improvement of the experimental design for future studies.

Analysis of Variance↗
PubMed1988

An identified histaminergic neuron can modulate the outputs of buccal-cerebral interneurons in Aplysia via presynaptic inhibition.

We have identified 2 buccal-cerebral interneurons (BCIs), B17 and B18, that appear to be involved in the coordination of feeding behavior in Aplysia. The BCIs have their cell bodies in the buccal ganglion, but send axons to the cerebral ganglion via the cerebral-buccal connectives. The BCIs appear to make monosynaptic connections with neurons in the cerebral ganglion that modulate extrinsic muscles involved in feeding behavior. B17 and B18 are activated antiphasically during a motor program induced by stimulating the esophageal nerve and appear to "read out" different phases of the buccal program to different cells in the cerebral ganglion. B17 and B18 are not necessary, and probably not sufficient, to generate the buccal program. These BCIs, and other cells like them in the buccal ganglion, may be capable of coordinating the activity of the intrinsic muscles of the buccal mass with the activity of its extrinsic muscles, and perhaps with those of the lips, mouth, and tentacles. Identified histaminergic neuron, C2, can modulate the outputs of the BCIs onto their synaptic followers in the cerebral ganglion. Firing of C2 inhibits spiking of the BCIs, probably via cerebral-buccal interneurons. C2 also decreases the size of the EPSP that B17 and B18 evoke in cerebral neuron C4. C2 appears to do so monosynaptically, and it decreases the conductance of C4, ruling out one possible postsynaptic mechanism of action. Variance analysis of the EPSPs evoked by B18 supports the hypothesis that C2 acts presynaptically to decrease the release of transmitter. Applications of histamine to the solution bathing the neuron mimic the effect of firing C2 and reduce the size of the EPSPs B18 induces in C4. The bath-applied histamine appears to act directly on B18, since it elicits a voltage-dependent increased conductance hyperpolarization recorded in the soma of B18, and the hyperpolarization persists in a solution in which synaptic transmission has been blocked. Histamine did not produce any marked changes of the duration of a TEA-broadened somatic action potential of B18. To the extent that the soma of B18 reflects the membrane properties of its synaptic terminal region, the data suggest that histamine may produce presynaptic inhibition by hyperpolarizing the synaptic terminal region.

Analysis of Variance↗
PubMed1987

Pathogenetic significance of venous hyperoxaemia in retinopathy of prematurity.

Ten underweight newborns with severe retinopathy of prematurity (ROP) and 18 newborns with slight changes in the sense of ROP were compared with 66 healthy infants. The distribution of 13 possibly pathogenetically effective features in these 3 groups of patients was studied by means of variance analysis. The greatest significance resulted for multiple blood transfusions and exchange transfusions. From this it was concluded that the toxic oxygen effect on the immature retina was probably more dependent on the venous PO2 (determined by Hb concentration, O2-affinity, arterial PO2, and blood flow) than on the isolated arterial PO2.

Analysis of Variance↗
PubMed1973

On the virulence of group A streptococci: evidence for virulence factors other than M-protein and capsule.

Group A streptococci from parent cultures (PC) of six different serotypes were selected by rotation with human blood (RHB) or by serial passage via intraperitoneal inoculation in mice (MP). M-protein content of PC, RHB and MP streptococci of each serotype was determined in quintuplicate by radial immunodiffusion against type-specific antisera. Hyaluronic acid content was determined in quintuplicate colorimetrically after treatment of streptococci with hyaluronidase. Data were subjected to variance analysis. LD(50) for mice of PC, RHB and MP streptococci, inoculated intraperitoneally, was also determined. It was observed that MP streptococci virulent for mice were rich in M-protein and hyaluronic acid. However, RHB streptococci of M-protein and hyaluronic acid content similar to MP streptococci were not virulent for mice. This dichotomy with respect to mouse virulence infers the existence of as yet unidentified streptococcal virulence factors, in addition to M-protein and capsule.

Analysis of Variance↗
PubMed1979

[Attempt at applying statistical methods to delimit melanoma types].

By means of the "multivariate variance analysis" ("MANOVA"; Friedrich and Olfert, 1977), we tried to differentiate the histologic types of malignant melanomas also by quantifiable criteria. The investigation depended upon data from 411 patients. Difficulties arose from incomplete data material. But in principle, the indication of this method is given in such problems. If the number of cases could be augmented, the method would be helpful as a support for diagnostic quality control.

Adolescent↗
PubMed1977

[Relationships between the value of combined PAH-inulin clearance, the kidney-cortex index as well as between additional radiographic findings in chronic pyelonephritis].

In 85 patients with ascertained chronic pyelonephritis the relations between the measured values of the combined PAH-inulin-clearance, the index of the adrenal cortex and other radiological findings were investigated. Here the determination of the cortex of the adrenal cortex resulted in a better correlation with the sizes clarification values than the calculation of the size of the kidney. By variance analysis (F-test) significant differences between the individual function groups became clear.

Aminohippuric Acids↗
PubMed1978

[Multivariate variability investigations of acoustically evoked slow potentials (AEP) (author's transl)].

By means of the multivariate variance analysis the ratio of intra- and interindividual variability of the AEP--time function was investigated. 90 AEP from 9 normal hearing persons (10 AEP from every person, averaging sessions spread over 10 weeks) were analyzed. The 10 AEP of every person were treated as a random sample. A multivariate pair comparison (single comparison between samples) on the basis of 12 variables (time points) showed only for 1 out of 36 sample pairs no significant differences between the sample averages. By applying the discriminant analysis false classifications resulted only for 7 out of the 90 AEP (approximately 8%). These facts mean, that even throughout the time of 10 weeks the intraindividual differences of the AEP--time behavior are significantly smaller than the interindividual ones.

Acoustic Stimulation↗
PubMed1983

Comparison of six treatments of ascites in patients with liver cirrhosis. A clinical trial.

UNLABELLED: A national multicenter study (34 centers) compared six treatments in 328 patients with cirrhotic ascites. Excluded were patients with g.i. bleeding within the last six months, chronic encephalopathy, cancer, tuberculosis or the following complications persisting after three weeks: acute encephalopythy, fever greater than 38 degrees C, infected ascites or biochemical abnormalities: blood urea greater than 8 mmol/l, natremia less than 130 mmol/l, kaliemia less than 2.5 or greater than 5.5 mmol/l, WBC greater than 12000 mm3, total bilirubin greater than 85.5 mumol/l. In each center patients were randomized into two treatment groups, each center using 2 of 6 proposed treatments: (1) Spironolactone and 500 mg Na p.d (77 patients), (2) Spironolactone + furosemide or Moduretic (amiloride + hydrochlorothiazide) and 500 mg Na p.d (80 patients), (3) Spironolactone + Furosemide or Moduretic and unrestricted sodium diet (86 patients), (4) Concentrated ascites reinfusion and 500 mg Na p.d. (36 patients), (5) Unmodified ascites reinfusion and 500 mg Na p.d. (23 patients), (6) Slow ascites drainage and 500 mg Na p.d. (31 patients). Statistical analysis methods were X2, variance analysis and Spotvoll-Stoline and Dunn-Sidak tests. Before treatment, there was no significant difference between the 6 groups. RESULTS: After one month of treatment, no difference was found in the frequency of total or partial regression of ascites, complications of cirrhosis, mortality, acceptability of treatment. Mechanical treatments induced more rapid weight loss but more frequent recurrence; comparison of groups 2 and 3 did not confirm any benefit associated with unrestricted Na diet. Duration of treatment and hospitalization were shorter in group 4 than in groups 3 and 6.

Amiloride↗