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M Pluta

Publications and source records attributed to M Pluta.

At least 19 recordsLinked to original sources
PubMed2006

On interference effects in the elastodynamic Green's functions G33(x, omega) of Si and GaAs.

In this paper, we analyze interference effects present in the elastodynamic Green's functions G33(x,omega) of the cubic crystals Si and GaAs, which are associated with folded portions of the wave surface of the slow transverse (ST) acoustic mode. G33(x,omega) represents the three dimensional extension of the amplitude distribution imaged in the transmission acoustic microscopy of these crystals. The intensity contrast for oscillations of a particular wave vector k in the interference pattern is determined essentially by the 3D Fourier transform of G33(x,omega)G33*(x,omega). According to the Fourier autocorrelation theorem, that transform is equivalent to the autocorrelation function of the corresponding distribution G(33)(k,omega) in k-space. We show that due to the linear mapping between k-space and the slowness vector s-space, the interference phenomena discussed here are related to geometrical features of the slowness surface of the ST mode. We present calculations of these effects based on the angular spectrum technique.

Journal Article↗
PubMed2006

Longitudinal study of patients after surgical treatment for cervical lesions: detection of HPV DNA and prevalence of HPV-specific antibodies.

The principal aims of this study were to test whether persistence of human papillomavirus (HPV) DNA is predictive of recurrent disease in women after surgical treatment for cervical lesions, to distinguish between persistent and newly acquired HPV infection, and to observe the effect of surgical treatment on levels of HPV-specific antibodies. A group of 198 patients surgically treated for low-grade and high-grade squamous intraepithelial lesions and 35 age-matched controls were monitored for 18 months at 6-month intervals. The presence of HPV DNA in cervical smears was detected by means of consensus polymerase chain reaction, and serum levels of HPV-specific antibodies to HPV types 16, 18, 31, 33, and 45 were measured. In ten patients positive for HPV type 16 in consecutive samples, the HPV 16 variants were identified using a polymerase chain reaction specific for the long control region. Data regarding demographics, risk factors for cervical cancer, and risks related to HPV exposure were collected through a patient questionnaire. Subjects persistently positive for HPV DNA were more likely to present with cytological and/or colposcopical abnormalities. A higher reactivity to HPV-specific antibodies was observed in these women at the 18-month follow-up visit. All ten patients with HPV 16 infection detected in consecutive samples showed persistence of either the same prototype or the same variant during the follow-up period. Risky sexual behavior and smoking were more common in patients than in controls. Persistent HPV infection as demonstrated by both HPV DNA detection and antibody detection appears to be a risk factor for the recurrence of pathological findings in women after surgery. An individually based approach to surgical treatment is an important factor in the outcome of disease at follow-up.

Adolescent↗
PubMed2006

[Sentinel lymph nodes identification in vulvar cancer--methods and technique].

OBJECTIVE: To evaluate detection of sentinel lymph nodes (SLN) in squamous vulvar cancer with blue dye and 99mTc. The study describes technique of application, timing, management, detection rate (DR), specific side detection rate (SSDR) and false negative rate. DESIGN: Prospective clinical study. SETTING: Department of Obstetrics and Gynecology, Charles University Prague, 2nd Medical Faculty, Teaching Hospital Motol. PATIENTS AND METHODS: 46 women with squamous cell carcinoma tumors stage I or II, <4 cm with no clinical suspect lymph nodes were included. Blue dye alone was used in 16 women and the combination of 99mTc and blue dye was used in 30 women. Radiocoloid 99mTc was applied 3-5 hours and blue dye 3-5 minutes prior to ingvinal incision. RESULTS: We detected 88 SLN in 61 inguinal spaces. The detection rate in the blue dye group was 68.8 % (11 cases). One false negative SLN (6.3 %) appeared in this group. In blue dye+ 99mTc group detection rate was 100 % with no false negative SLN. CONCLUSION: Detection of SLN in squamous vulvar cancer with the combination of 99mTc and blue dye was statistically significantly more effective than using the blue dye alone.

Adult↗
PubMed2006

[Fertility sparing surgery in early cervical cancer today and tomorrow].

OBJECTIVE: Describtion and evaluation of proposed protocol for conservative, fertility sparing surgeries in the treatment of early stages of cervical cancer and its comparison to most frequently used protocols regarding its reproductive and oncological outcomes. DESIGN: Prospective clinical study. SETTING: Department of Obstetrics and Gynecology, Charles University Prague, 2nd Medical Faculty, University Hospital Motol. PATIENTS AND METHODS: 24 patients that fitted into the inclusion criteria were recruited in the study (6 in stage T1A2 and 18 T1B1). Inclusion criteria were: tumor less than 20 mm in largest diameter, less than 1/2 of the stromal invasion, SCC serum levels within normal range, signed informed consent. Minimum follow up was 24 months. Described therapeutic protocol, evaluation of oncological and reproductive outcomes and comparison with different fertility sparing regimens were performed. RESULTS: In four cases (16.7%) peroperative histopatghological evaluation (frozen section: FS) detected metastatic involvement of lymphatic nodes. In one case (4.1%) following 14 months since initial surgery, reccurent disease in uterine isthmus was detected. The patient underwent chmotherapy and she is 36 months in complete remission. In the series of 15 women planning pregnancy 11 subjects become pregnant so far. Eight deliveries occurred (one in 24th week of gestation--650g, one in 34w--2240g, one in 36w--2700g and five between 37-39w). Only one newborn was delivered in the cathegory of extreme prematurity. CONCLUSION: Sentinel node detection involving peroperative histopathological evaluation followed by subsequent serial processing and together with 2-step therapeutic management increases efectivity of fertility sparing surgeries. Less radical surgery on uterine cervix: reconisaton (in stage IA2) or simple trachelectomy (in early stage T1B1) with negative finding after laparoscopic lymph node dissection has comparative results with radical trachelectomy and abdominal radical trachelectomy. Pregnancy rates and pregnancy outcomes particularly regarding in term delivery is the best after treatment of early stages of cervical cancer using proposed protocol, while very promising results are published in studies with radical vaginal trachelectomy as well. Results published for the patients treated with abdominal radical trachelectomy are unsatisfactory.

Adult↗
PubMed2005

[Abdominal hysterectomy--risk factor in development of urinary incontinence? Results of a questionnaire study].

OBJECTIVE: To evaluate the risk of urinary incontinence development after abdominal hysterectomy for benign gynecological disease. DESIGN: Retrospective questionnaire study. SETTING: Obstetrics and Gynecology Department, Charles University 2nd Medical Faculty and Teaching Hospital Motol, Prague. METHODS: Questionnaire study of women in which abdominal hysterectomy for benign gynecological disease was performed from January till December 2001 at our Department of Gynecology and Obstetrics. The questionnaire included questions about symptoms of stress, urge and mixed urinary incontinence. They were evaluated in connection with age, parity, hormonal status and body mass index. Student t-test was used for the statistical analysis. RESULTS: 114 (59.7%) from all sent-out questionnaires were obtained. In 15.8% cases (18 from 114) de novo urinary incontinence after surgery developed. 77.8% (14 from 18) from these patients suffered from genuine stress incontinence. The rest (4 from 18) of the women had symptoms of mixed incontinence. Study results draw attention to 13.1% women (15 from 114) in which preoperative stress incontinence persisted even after hysterectomy. Preoperative stress incontinence was cured in 6.1% (7 from 114) cases after hysterectomy. Age, parity, hormonal status and body mass index were not statistically different in all groups after surgery. CONCLUSIONS: The results of the study show relatively high risk of urinary incontinence development after abdominal hysterectomy in previously continent women. The results also show high persistence of the stress incontinence symptoms in women who did not inform about their incontinence even if they were asked about it. Higher quality of further health education of the women with drawing their attention to both the possibility of surgical treatment of urinary incontinence simultaneously with hysterectomy are the most important aspects how to make the current gynecological surgical therapy more effective.

Adult↗
PubMed2005

Squamous intraepithelial lesion-microinvasive carcinoma of the cervix during pregnancy.

OBJECTIVE: The objective of this work was to assess proper management of squamous intraepithelial lesion (SIL) and microinvasive carcinoma during and after pregnancy, to assess risks of punch biopsy and conization in pregnancy and to assess regression, persistence and risk of progression with low-grade (L) and high-grade (H) SIL. METHODS: We carried out a prospective study of 167 pregnant women from our colposcopic unit who were referred to us for abnormal cytological findings between 1997 and 2002. The diagnosis of precancerosis was verified in all of the women by punch biopsy, suspect microinvasive carcinoma needle or LETZ conization up to the 20th week of pregnancy. All women were followed-up during the pregnancy and 24 months after their deliveries. RESULTS: In 23 women with suspect early invasion we performed conization during the pregnancy (weeks 13-23). There were six cases (26.1%) of microinvasive carcinoma and 17 cases (73.9%) of HSIL. One pregnancy aborted two days after the conization. No other obstetrical complications were recorded and there were no premature deliveries. Sixty-two women with HSIL were only followed-up during their pregnancy. We observed complete regression of HSIL during the study in 14 patients (22.6%), regression to LSIL in 17 patients (27.4%), persistence in 25 patients (40.3%) and progression to microcarcinoma in six cases (9.7%). Eighty-two patients were followed up for LSIL. Complete regression of LSIL was observed during the study in 40 cases (48.8%), persistence in 24 cases (29.2%) and progression to HSIL in 18 cases (22.0%). CONCLUSION: For LSIL and HSIL during pregnancy the above follow-up is a sufficient and safe protocol. Suspect microinvasive carcinoma should be treated by conization, which is a safe procedure until the 24th week of pregnancy.

Adult↗
PubMed2004

Inversion of acoustic diffraction fields in anisotropic solids.

We show that the fast Fourier transform (FFT) technique provides a computationally efficient method of calculating 2D amplitude and phase images of complex wave fields generated and measured in elastically anisotropic solids by phase sensitive acoustic microscopy. Further, we discuss how this technique can be used to treat inverse problems such as source reconstruction, image quality assessment, and the determination of elastic constants.

Journal Article↗
PubMed2004

[Sentinel lymph node mapping in early-stage cervical cancer].

OBJECTIVE: The aim of this study was to determine the utilization and usefulness of intraoperative lymphatic mapping and sentinel node identification with Patent blau in early stage cervical cancer. DESIGN: Prospective case observational study. SETTING: Department of Obstetrics and Gynecology, Charles University, 2nd Medical Faculty, Faculty Hospital Motol, Prague. METHODS: From February 2000 to July 2002, 100 patients undergoing surgery for early cervical cancer were included, 21 patients undergoing SNI (sentat laparoscopy and 79 patients undergoing SNI at the time of radical abdominal hysterectomy after installation of blue dye (PatentBlau V 2.5%). We carefully inspected the lymphatic channels and sentinel nodes and performed a preoperative frozen section of sentinel nodes. Finally, complete lymphadenectomy was done. RESULTS: There was one false-negative result in the group of 100 women. In the group of tumors less than 20 mm the detection rate was 90.5% when laparoscopic detection was performed and 91.7% in laparotomic detection. In tumors more than 20 mm the detection rate was 80% and in the group of 25 women with "bulky" tumors IB2 after neoadjuvant chemotherapy the detection was 60% only. We analysed locoregional distribution of 176 sentinel lymph nodes in 75 women not undergoing neoadjuvant chemotherapy and distribution of 20 positive sentinel nodes. CONCLUSION: Detection of sentinel nodes in early stages of cervical carcinomas using patent blue dye is a easy-to-perform, feasible and cheap method. Additional studies are necessary using radioisotope to improve detection rate. Another prospective studies should evaluate the role of SNI in reduction in surgical radicality.

Adult↗
PubMed2001

[Regression of hCG in various types of molar pregnancies--clinical course and prognosis].

OBJECTIVE: To evaluate spontaneous regression curves of hCG serum positivity in patients with surgically treated molar pregnancies. Comparison of complete, partial and invasive mole. The study should result in optimalisation of follow up criteria of molar pregnancies in respect to their potential malignant change. DESIGN: Retrospective comparative clinical study. SETTING: Obst. Gyn. Dpt., Oncogynecology div., 2nd Medical Faculty, FNM, Charles University Prague, Pathology Dpt., 2nd Medical Faculty, Institute of Biology and Medical Genetics. METHODS: Evaluation of spontaneous regression curves of serum hCG levels in 104 molar pregnancies. 46 patients with partial hydatiform mole, 48 patients with complete hydatiform mole, 10 patients with invasive mole. Serum hCG levels were detected by radioimunoassay (RIA) in the first period and imunochemoluminisent assay (LIA) in the second period. Regression curves of hCG positivity in particular moles were statistically evaluated by Fischer test and t-test. RESULTS: There is statistically significant difference in spontaneous regression of hCG positivity in different types of molar pregnancies. Recommended criteria for gestational trofoblastic disease (GTD) diagnosis and follow up are fully applicable in clinical practice. There is exception in partial hydatiform moles, where plateau in hCG regression does not necessarily implicate chemotherapy in patient with good compliance. CONCLUSION: Early diagnosis of GTD predominantly due to the widespread use of ultrasonography changes classical clinical features of molar pregnancies. Spontaneous regression in hCG positivity in serum is more rapid in patients with partial hydatiform mole, slower in complete hydatiform mole and invasive mole. There is no significant change in malignant potential regarding early detection and treatment.

Chorionic Gonadotropin↗
PubMed2000

The measurement and numerical modelling of the diffraction field of a spherical ultrasonic transducer working in the air at the frequency of 1.3 MHz

This paper presents the results of measurements of the acoustic diffractive field in the focal area of a spherical ultrasonic transducer working in air at a frequency of 1.3 MHz. The measurements show some differences when compared to the theoretical distribution. Computer modelling of the transducer aperture complex function and the numerical simulation of its radiation are used to explain those differences. It is shown that the wave aberration of threefold symmetry (described by the Zernicke polynomial) and the random distribution of grains in the impedance matching layer are the main causes.

Journal Article↗
PubMed2000

Synthetic aperture imaging by scanning acoustic microscopy with vector contrast

Based on phase sensitive scanning acoustic microscopy (PSAM), a novel scheme suitable for volume imaging has been developed. The method employs synthetic aperture insonification combined with synthetic aperture imaging. Excitation and detection are performed by planar scanning of two focusing transducer and vector (phase and amplitude) detectors for the ultrasonic wave packages observed in transmission. Examples for applications of the scheme, including technically relevant simplifications based on reduced dimensions of the scan ranges, are presented. Detection schemes already applied for non-destructive testing (NDT) and non-destructive evaluation (NDE) of the mechanical properties of functionally graded materials are an example for the application of the generalised approach presented here with reduced dimensions of the scan. The technique is suitable for NDT and NDE imaging respectively with three-dimensional resolution.

Journal Article↗
PubMed2000

Angular spectrum approach for the computation of group and phase velocity surfaces of acoustic waves in anisotropic materials

The decomposition of an acoustic wave into its angular spectrum representation creates an effective base for the calculation of wave propagation effects in anisotropic media. In this method, the distribution of acoustic fields is calculated in arbitrary planes from the superposition of the planar components with proper phase shifts. These phase shifts depend on the ratio of the distance between the planes to the normal component of the phase slowness vector. In anisotropic media, the phase shifts depend additionally on the changes of the slowness with respect to the direction of the propagation vector and the polarization. Those relations are obtained from the Christoffel equation. The method employing the fast Fourier transformation algorithm is especially suited for volume imaging in anisotropic media, based on holographic detection in transmission of acoustic waves generated by a point source. This technique is compared with measurements on crystals performed by phase-sensitive scanning acoustic microscopy.

Journal Article↗
PubMed1993

[Clinical documentation in obstetrics and collection of relevant data with reference to the structural reform law. Results of a survey of 72 clinics].

This study was conducted on the spread and usage of computer-aided software programme (GDS) in 72 obstetric departments. Standardised questionnaires were sent to universities and hospitals to ask for information on registered perinatal data. The record with the hand-written delivery book cannot record all data needed for quality protection as the PC is able to list. 89% of the obstetricians evaluate their clinical data regularly by statistical survey and classification. By analysing the general trend they can critically assess their actual obstetrical management. The PC is established in 83%, functions without technical problems in 92% and is optimal in the sequence of operation in 57% of all departments questioned. Overtime hours for the staff could be reduced in 11%, if a computer was used, and in 13% the nurses could take more care of mother and child because of less official red tape. Independent of the size of the department and the data processing knowledge of the staff, the software programme runs efficiently. The comprehensive basis data documentation with all perinatal and neonatal data is used to its full extent in 100% of the cases and documents the clinical effectivity. With regard to the standardised hospital quality control process by the modified requirements in the public health legislation, the directors of the hospital departments are able to assess the quality control and show economic independence.

Attitude of Health Personnel↗
PubMed1987

Single-ring polanret phase-contrast system.

An extremely simple, modified polanret phase-contrast system has been developed. It uses only a single polarizing ring, instead of three zonal polarizers as required in Osterberg's original polanret system (manufactured by the American Optical Corporation). The modified system is much more easily manufactured and its economy of light is twice as good. However, it does require an easily accessible microscope objective exit pupil, where the polarizing ring must be located.

Humans↗
PubMed1986

[Labor documentation system: a simplified method of documentation and quality control in obstetrics].

A simple on-line data collection system was developed for facilitating documentation and quality assessment in perinatal medicine. A microcomputer is used for acquisition of the most important obstetrical data. The system substitutes the handwritten birth notification form and permits automatic medical reporting. In addition an information system for day-to-day clinical routine is provided. Special programmes allow the compilation of statistical analysis as requested by the government as well as for internal quality assessment.

Computers↗
PubMed1985

[Child development after abdominal version of the fetus from breech presentation to vertex presentation near term].

The prospective study presented here describes the results of follow-up examinations of the developmental stage of 116 children born between 1977 and 1980 in whom abdominal version of the foetus from breech presentation to vertex presentation was performed near term. The children were examined according to the Denver Developmental Screening Test at the age of 2 to 5 3/4 years in various fields (social contacts, minor motor functions and adaptation, speech and major motor functions). Children with abnormal findings were subjected to special examinations. Those with disturbed development were re-examined after one year. In the entire group of children there were four with psychomotor retardation of speech, and two further children with minimal cerebral motor disturbances. The children had been detected early during infancy. These results, classified as secondary morbidity (disturbances of speech and minimal cerebral motor disturbances) were analysed taking into account the results of version (successful and unsuccessful version) and other obstetric factors (course of pregnancy and birth, method of delivery, biochemical examinations during and after birth, age of mother and socioeconomic status of parents).

Attention Deficit Disorder with Hyperactivity↗
PubMed1985

[The effect of low blood pressure on venous function during and outside of pregnancy and therapeutic consequences].

Orthostatic dysregulations occur ten times more frequently in gravidae with low blood pressure than in those in whom it is normal. This condition can result in a temporarily insufficient blood supply to the uterus and hence to the foetus. As a consequence, abortions, premature and abnormal births, and complications during labour and lying-in occur more frequently among hypotonic women. Pathophysiologically, orthostatic dysregulations are caused by large quantities of blood remaining in the peripheral veins. In this connection it is well known that the hormonal change-over during pregnancy reduces venous tone, thus causing venous return to the heart to deteriorate. It has not yet been investigated whether or respectively how low blood pressure in pregnant and non-pregnant women affects venous hemodynamics and what effect treatment with dihydroergotamine (DHE) has. In order to answer these questions the authors performed 240 venous function measurements in a total of 140 pregnant and non-pregnant, hypotonic and normotonic women. Using a simple, non-invasive photoplethysmographic method, light reflection rheography (LRR), a check was first made as to whether there are differences in venous pumping in non-pregnant hypotonic as opposed to normotonic women. In 20 normotonic subjects the delta R mean value for venous drainage was 165 mV, while in 20 hypotonic women it was only 114 mV (p less than 0.001). While, on the basis of a corresponding classification, all of the normotonic women were classified as having normal veins or merely slight venous insufficiency, 14 hypotonic women were found to have moderately severe or severe venous insufficiency (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗