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At least 721 records · Page 40Linked to original sources
PubMed1992

[Comparative effects of sodium fluoride and hormonal replacement therapy on bone metabolism in osteoporotic women with high fracture risk. Results of monitoring for 2 years].

Thirty seven postmenopausal women aged under 65 with densitometric osteoporosis defined by a bone density value below the 80th percentile of the osteoporotic population but without identifiable crush fractures, were treated and monitored for two years using clinical, laboratory and densitometric parameters. Sixteen of them were given hormonal replacement therapy combining percutaneous or transdermal 17 beta estradiol with a progestogen and the other 21 sodium fluoride at the dose of 50 mg/d combined with calcium and vitamin D. There was a significant increase in vertebral bone density in both groups: 6.3 +/- 0.9 per cent for hormone treatment and 7.1 +/- 1.5% for fluoride after 2 years, while it fell in a control group. The increase was linear with fluoride, while 2/3 of the gain was acquired by the end of the first year of hormonal therapy. Nine of the 16 patients on hormonal therapy and 9 of the 21 taking fluoride showed a significant vertebral gain at 2 years (greater than or equal to 0.043 g/cm2). There was no parameter which enabled the identification of "responders" before treatment. There was no difference in changes in femoral bone density between patients treated with fluoride and controls. From a laboratory standpoint, hormonal therapy caused a significant fall at 12 months in the urinary calcium/urinary creatinine ratio, and a non-significant fall in osteocalcin at 2 years. With fluoride, there was a marked rise in osteocalcin and a more moderate rise in alkaline phosphatase, reflecting stimulation of bone formation without any variation in resorption. In conclusion, this study shows the ability of both these types of treatment of increasing, by different mechanisms, the vertebral bone density of osteoporotic women. However, it does not indicate the extent to which this gain in bone density might have a positive influence on fracture risk.

Age Factors↗
PubMed2004

A mathematical model of the response of semicircular canal and otolith to head rotation under gravity.

The mathematical model of the system composed of two sensors: semicircular canal and sacculus, is presented. The system is described by three series of blocks: biomechanical block, mechanoelectrical transduction mechanism and hair cell ionic currents and membrane potential dynamics. The response of the aforecited system to various stimuli (head rotation under gravity and falling) was investigated. The identification of the model parameters was fulfilled for the experimental data, obtained for the axolotle (Ambystoma tigrinum) in Institute of Physiology, Autonomous University of Puebla, Mexico. The comparative analysis of canal and sacculus membrane potential was realized.

Acceleration↗
PubMed1991

[Granuloma in Crohn's disease of the colon and rectum--a study of resection specimens].

The aim of the present study was to investigate frequency and distribution of granulomas in resected specimens of patients with well known Crohn's disease. Granulomas were observed in 57% (8/14) of all cases. Their distribution varied remarkably between different sections of the same resectional sample as well as between the patients. 11.6% of all granulomas were found within the lamina propria, 42.9% within the submucosa, and 45.5% within the muscularis propria. The mean value per cm muscularis mucosae was 0.85 +/- 0.82 granulomas. Caused by the heterogeneity in frequency and distribution there is no guarantee for a successful identification of this helpful parameter. During the last years the diagnosis Crohn's disease became more and more certain even in absence of granulomas. Therefore they are an useful but dispensable feature.

Adolescent↗
PubMedDate not supplied

Analysis of evoked potentials in measuring-analyzing ENG-microcomputer system.

The microcomputer system of measurement and analysis of equilibrium organ examinations was performed in the paper. Organization and functions of computer file of examined patients and results of anamnesis and organization of measuring course were discussed. Detailed description of used technique and methodology, kind identification of ENG diagnostic parameters, obtained results and forms of its graphic presentations on microcomputer monitor or graphic printer was performed.

Electronystagmography↗
PubMed1990

Temporal characteristics of saccadic eye movements induced by auditory stimuli.

Records of horizontal saccadic eye movements made in response to auditory stimuli in the absence of any target related visual stimuli were obtained from two normal human subjects. A band-limiting derivative filter was convolved with records of eye position to obtain estimates of eye velocity. Eye position and velocity records were analyzed off-line to determine the characteristics of the audio-ocular response (AOR). The latency of the AOR decreased with increasing target movement amplitude. The AOR also exhibited lower peak velocity and longer duration than previously reported visually induced saccades. The time at peak velocity increased as saccade amplitude increased until for eye movements with amplitudes greater than 15 degrees, time at peak velocity showed little further increase. Finally, the AOR displayed a high incidence of dynamic overshoot for abducting movements of the right eye and a low incidence of dynamic overshoot for adducting movements of the right eye. System parameters estimated using system identification techniques indicate that the pulse portion of the active state tension driving the agonist muscle is of lower magnitude for auditory saccades than for visual saccades.

Eye Movements↗
PubMedDate not supplied

[Methods of analyzing hematologic characteristics based on light scattering].

The methods of simultaneous identification of hematological blood parameters are described, i.e. general hemoglobin concentration, relative concentrations of hemoglobin derivatives, erythrocyte volume concentration, some erythrocyte aggregational parameters, checked on the same methodological basis. The tests were carried out on the banked blood samples. Their authenticity and accuracy are proved by the data derived from other independent methods. The preference of the offered approaches used for blood parameters tests compared to the ones presently used are being discussed.

Erythrocyte Aggregation↗
PubMed1988

Accuracy in the noninvasive estimation of pulmonary blood flow by identification of the CO2 uptake system.

Estimation of pulmonary blood flow, controlled by a roller pump, was carried out in dogs using a system identification technique. The system parameters in a linearized CO2 uptake model were estimated by the maximum-likelihood method from the input consisting of alveolar ventilation and inspired pCO2 and the output of end-tidal pCO2. The auto- and cross-correlations of the residuals showed that the model used for estimation was appropriate. The pulmonary blood flow calculated from the system parameters contained a degree of error which showed an average coefficient of variation of 23.8%. Error analysis revealed that the main sources of error lay in the estimates and in the error-magnifying effect arising in the calculation of the flow from these estimates. Reduction of the error in the estimates requires a long set of data for estimation; on the other hand, the error-magnifying effect is determined by physiological constants, so that it cannot be small even in clinical application.

Animals↗
PubMed1987

Assessment of assertion.

Behavioral assessment of assertion is an evolving technology. Although there have been many recent advances in the assessment of assertion, many unresolved issues continue to plague researcher and clinician alike. At a conceptual level, a precise theoretical rationale of assertion has yet to be articulated and accepted. Comprehensive identification of the various parameters that influence assertive responding have not been adequately evaluated, although person and situational variables are widely accepted parameters. Although a plethora of assessment instruments and strategies have emerged, more attention needs to be diverted to establishing their psychometric properties. There have been some promising starts, though there continues to be relatively little psychometric support for the adequacy of existing measures. Several self-report instruments have reasonably well-documented reliability and validity, but questions remain regarding the accuracy of self-reported assertion. In addition, a flood of new instruments continues the proliferation of measures. Researchers would be better advised to direct their efforts to establishing psychometric support for the more promising of the existing instruments than in continuing to expand energy on unproven new measures. Serious reservations have emerged regarding, in particular, the external validity of role-play assessment and cloud the confidence that can be placed on findings generated from role-play measures. The issues that have been critically identified throughout this chapter are not new. They occur time and time again in the assessment literature of the past decade. Yet the field continues to reflect inattention to cautions that have been repeatedly voiced. Measures continue to flood the literature without adequate psychometric support, and researchers rush toward outcome evaluation without attending to the questionable utility of findings generated from unproven measures. There has been a great deal of progress in a relatively short period of time. However, clearer answers are necessary before scientific credibility can be established for social skills research in general--and assertion research in particular.

Arousal↗
PubMed1987

[Hamartoma of the lung. Dysontogenetic lesion or true tumor? Study of 100 personal cases].

100 hamartomas of the lung (89 operative and 11 autopsy specimens were examined in detail and all parameters statistically correlated. Clinical identification and diagnosis have improved continuously in the last two decades. Men are affected more frequently. The hamartomas of the middle lobes were exceptional from several points of view (size, growth form, age). The typical hamartoma does not become malignant. Those patients who have a co-existent bronchial carcinoma are generally younger than those who have malignant disease only. Precise investigation of various individual criteria demonstrated that the replacement of the old dysontogenesis theory through the concept of pure tumorigenesis (mesenchymoma) is not justified.

Adolescent↗
PubMed1981

Determinants of response to antimetabolites and their modulation by normal purine and pyrimidine metabolites.

Two areas of investigation are discussed: (a) the identification of critical biochemical parameters that may lead to prediction of response of tumor cells to antimetabolites, such as 1-beta-D-arabinofuranosyl-cytosine (ara-C) and 5-FU, and (b) the potential use of normal purine and pyrimidine metabolites in the selective and specific modulation of critical parameters related to ara-C and 5-FU activity. The results presented indicate a strong correlation between ara-CTP formation and retention in leukemic cells and response of animals with leukemias or patients with acute myelocytic leukemia (AML) treated with ara-C or a protocol containing ara-C. Furthermore, thymidine was found to be an effective modulator of the intracellular pools of dCTP and ara-CTP in rats, bone marrow, small intestine, and colon tumor cells. The mechanism of this effect is unclear, but initial evidence indicates that specific scheduling of the sequential administration of the metabolite and the antimetabolites may be important in determining increased selectivity of antitumor effects. In vivo studies with fluorinated pyrimidines have focused on quantitating 5-fluorodeoxyuridine monophosphate (FdUMP) pools and their retention, and on the incorporation of fluorouridine (FUR) into RNA of sensitive and resistant L1210 cells. The results suggest that the retention of intracellular FdUMP pools above a threshold may be a more critical determinant in selectivity than the initial FdUMP levels achieved in target cells. Thymidine has been demonstrated to alter the pharmacokinetic parameters of 5-FU in man and in mice, but a selective modification of the antitumor activity of 5-FU has not yet been unequivocally demonstrated.

Animals↗
PubMed1982

Computation of preoperative diagnosis probability for follicular adenoma and carcinoma of the thyroid on aspiration smears.

Morphometric analysis of 23 follicular tumors (13 adenomas and 10 carcinomas) and 10 metastatic lesions from follicular thyroid carcinomas resulted in the identification of five significant parameters between the carcinoma and adenoma groups. With a classification rule using these features, the probability of a histologic diagnosis of adenoma versus carcinoma was computed for each case. Using threshold values of probabilities of 0.25 and 0.75, only 1 of the 33 cases was not correctly classified on the cytologic smear alone; the remaining 32 cases were correctly classified. These results indicate that morphometric analysis in follicular tumors of the thyroid may be of great help in individual patient care if used as a selective method by a well-trained cytopathologist.

Adenocarcinoma↗
PubMed1995

[Advances in biology and pathogenesis of multiple myeloma].

Plasma cell malignancy, multiple myeloma, is the prototype of monoclonal terminal-differentiated B cell proliferation that reveals a monoclonal Ig in the serum and/or urine of the majority of patients. New insights into the biology and pathogenesis of this entity are based on careful research to a complex cytokine network including TNF beta, IL-1 beta, and IL-6, many oncogene products such as bc1-2 protein, H-ras p-21 protein, and RB-1 product, and cell surface antigens associated with myeloma cells. The recent understanding on the mechanism for acquisition of IgV region diversity during B cell development has clarified the origin of the clonogenic cell in multiple myeloma. Further identification of new prognostic parameters as well as new therapeutic agents is necessary for the rational therapy of this refractory malignancy.

Aged↗
PubMed1994

[Natural history and prognostic factors of prostate cancer].

Our present knowledge of the natural history of cancer of the prostate has been acquired from anatomical and clinical observations. They have led to identification of the main prognostic factors of the disease, but as long as the biological and molecular mechanisms implicated in its development remain obscure, our knowledge is incomplete and treatment of its various stages can only be orientated empirically. The main problems which should be resolved by prognostic indications are found at two critical points of the disease: 1) in the case of localised cancer, avoiding radical treatment (surgery or physiotherapy), either for a small, stable tumour discovered by chance (occult cancer) or for an apparently localised tumour but where surgery alone would be ineffective because of a high positive margin or a high metastatic potential; 2) in the case of advanced cancer, to estimate the beneficial effects of early hormonal or nonhormonal treatment on the quality of life and on patient survival. Identification of simple prognostic parameters also aims to reduce the health cost involved in this type of cancer and to increase patient comfort by simplifying initial and subsequent investigations. Prognostic factors include both clinical data and laboratory chemistries. The latter are still the object of numerous and diverse studies involving basic science. The increasing diversity of such studies and preliminary publication without correlated large series has so far precluded judging the reliability of such factors for clinical use. In practice, tumoural volume and stage remain the two factors which can estimate the risk of progression when prostatic cancer is detected microscopically.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMedDate not supplied

[Echography applied in dermatologic diseases. A comparative preliminary study of the use of high-frequency transducers].

Ultrasonography (US) was first used in dermatology in 1979. During the last few years, US has evolved thanks to technological progress and its use has been on the increase, in dermatology, to study both localized and diffuse skin diseases. In this paper, the authors review and compare the results obtained with a 20 MHz transducer with those obtained with 7.5 MHz and 10 MHz transducers in the study of skin alterations. Three parameters were considered: lesion identification, spatial evaluation and US structure. Fifty-eight cases of localized and 48 of diffuse skin diseases were examined. The localized forms were benign in nature in 18 patients (3 nevi, 2 seborrheic keratoses, 3 ulcus cruris cases, 6 sebaceous and 2 liquid cysts). The other 40 patients had malignant neoplastic lesions (16 epitheliomas, 13 primitive melanomas, 1 metastatic melanoma, 8 lymphomas and 2 Kaposi's sarcomas). The 48 cases of diffuse conditions included 27 systemic sclerosis, 18 psoriasis and 3 lichen planus cases. The comparative analysis of the results obtained using the different types of transducers in the study of localized dermatoses showed no differences in lesion identification and in the depiction of their US features. On the other hand, the 20 MHz transducer was much more accurate than the others as regards the spatial evaluation of the lesions measurable in millimeters, whereas it poorly demonstrated the lesions > 1.5 cm. However, only the 20 MHz transducer could demonstrate the US features of diffuse conditions.

Evaluation Studies as Topic↗
PubMedDate not supplied

DNA content and proliferation activity in superficial transitional cell carcinoma of the bladder.

The identification of new prognostic parameters in Superficial Transitional Cell Carcinoma of the Bladder (STCCB) is important since conventional methods are often insufficient for prognostic purposes. We studied the proliferation activity and the DNA ploidy status of 60 pTa and pT1 Superficial Transitional Cell Carcinoma of the Bladder in relation to grade and recurrence rate. The proliferative activity was investigated by measuring the PCNA expression in paraffin embedded tissue sections. The DNA content was studied in Feulgen stained imprints by image analysis technique using a SAMBA 2005 analyser. According to our measurements a statistically significant difference was found in PCNA expression among tumors grade I, grade II, grade III (F = 5.43, p < 0.001), between tumors of the same grade with, and without recurrence (p < 0.001); and between recurrent and non-recurrent tumors (T58 = -6.03, p < 0.001). A statistically significant difference was also observed concerning the DNA-index among grade I, grade II and grade III (F = 4.81, p < 0.01), and between recurrent and non-recurrent tumors concerning the DNA DNA ploidy status (DNA-euploid vs. DNA-aneuploid tumors) (X2 = 24.96, p < 0.001). The recurrence status is also strongly influenced by the proliferation rate and the DNA ploidy status of tumors (X23 = 41.19, p < 0.001). No cases recurrence were found in the group of DNA-euploid tumors with PCNA. expression lower than 30%, in contrast a very high percentage of recurrence in patients with DNA-aneuploid tumors with PCNA expression higher than 30%. Although a small proportion of cases could not be included in me previous categories, STCCB may be classified in to main groups concerning the risk of recurrence. In keeping with this view of proliferation rate and DNA ploidy status could provide useful information, on the potential malignancy of Superficial Transitional Cell Carcinoma of the Bladder. However further studies are required to establish the clinical utility of these parameters.

Adult↗
PubMed1997

Association of PML-RAR alpha fusion mRNA type with pretreatment hematologic characteristics but not treatment outcome in acute promyelocytic leukemia: an intergroup molecular study.

In each case of acute promyelocytic leukemia (APL) one of three PML-RAR alpha mRNA types is produced, depending on the break/fusion site in the PML gene that is linked to a common RAR alpha gene segment: a short (S)-form type, PML exon 3 RAR alpha exon 3; a long (L)-form type, PML exon 6 RAR alpha exon 3; or a variable (V)-form type, variably deleted PML exon 6 RAR alpha exon 3. We evaluated whether PML-RAR alpha mRNA type is associated with distinct pretreatment clinical characteristics and therapeutic outcome in previously untreated adult APL patients registered to protocol INT 0129 by the Eastern Cooperative Oncology Group, the Southwest Oncology Group, and the Cancer and Leukemia Group B. Of 279 clinically eligible cases, 230 were molecularly evaluable, and of these, 111 were randomized to receive remission induction therapy with all-trans retinoic acid (ATRA) and 119 with conventional chemotherapy. Nine cases not excluded by central pathology review were PML-RAR alpha negative, and notably, none of five of these cases treated with ATRA achieved complete remission (CR). Among 221 PML-RAR alpha-positive cases, there were 82 S-form cases (37%), 121 L-form cases (55%), and 18 V-form cases (8%). Before any antileukemic therapy, the S-form type, compared with the L-form type, was associated with higher values for the white blood cell (WBC) count (median 2,500/microL v 1,600/microL; P = .009), the percentage of blood blasts plus promyelocytes (median 29% v 8.5%; P = .03), and the absolute blood blasts plus promyelocytes (884/microL v 126/microL; P = .019). Also, an increased percentage of S-form versus L-form cases had the M3 variant phenotype, 24% v 12% (P = .036). There were no differences between S-form and L-form cases in either CR rate (79% v 69%; P = .14) or disease free survival distribution (multivariate analysis adjusting for the association of S-form type and higher WBC count; P = .40). We conclude that the S-form type is associated with previously-identified adverse risk WBC parameters but that the identification of the S-form or L-form type of PML-RAR alpha mRNA, per se, does not predict clinical outcome or add to the value of an increased WBC count as a negative prognostic indicator in APL patients.

Adult↗
PubMed1997

Three-parameter flow cytometric analysis of rat spermatogenesis.

Mammalian spermatogenesis is a complex process which is not yet fully understood. In this paper we describe the analysis of rat spermatogenesis by means of 3-parameter flow cytometry. Since the analysis of DNA content only provides sufficient information for the identification of 4 cell populations, additional parameters were combined with propidium iodide (PI) staining. Immunostaining of the intermediate filament vimentin allowed the identification of somatic (vimentin positive) and germ (vimentin negative) cells. Utilizing the combination of DNA and vimentin staining, we have been able to quantitate the somatic cells present in a testicular cell suspension and to analyze somatic and germinal cells separately. Furthermore, the addition of mitochondrial staining with the fluorochrome nonyl acridine orange (NAO) allowed several cell subpopulations within each ploidy group to be distinguished. After 3-color staining and subsequent cell sorting, 11 testicular cell subpopulations could be identified: somatic cells, and 10 subtypes of germinal cells. The method described in this paper represents a valuable tool for the evaluation of spermatogenesis in both normal and perturbed situations.

Acridine Orange↗