Structure and thermodynamics of a UGG motif interacting with Ba2+ and other metal ions: accommodating changes in the RNA structure and the presence of a G(syn)-G(syn) pair

The self-complementary triplet 5'UGG3'/5'UGG3' is a particular structural motif containing noncanonical G-G pair and two U·G wobble pairs. It constitutes a specific structural and electrostatic environment attracting metal ions, particularly Ba2+ ions. Crystallographic research has shown that two Ba2+ cations are located in the major groove of the helix and interact directly with the UGG triplet. A comparison with the unliganded structure has revealed global changes in the RNA structure in the presence of metal ions, whereas thermodynamic measurements have shown increased stability. Moreover, in the structure with Ba2+, an unusual noncanonical G(syn)-G(syn) pair is observed instead of the common G(anti)-G(syn). We further elucidate the metal binding properties of the UGG/UGG triplet by performing crystallographic and thermodynamic studies using DSC and UV melting with other metal ions. The results explain the preferences of the UGG sequence for Ba2+ cations and point to possible applications of this metal-binding propensity.

Comparison of serum concentrations of environmental allergen-specific IgE in atopic and healthy (nonatopic) horses

Allergic responses in humans, horses and other species are mediated by immunoglobulin E (IgE) antibodies. Serum testing to detect allergen-specific IgE antibodies has been developed for dogs, cats and horses; this allows for the identification of allergens and determination of appropriate allergen- specific immunotherapies. This study compared serum allergen-specific IgE concentrations in atopic and healthy horses. The study was performed on Malopolski breed atopic (n=21) and nonatopic (n=21) clinically healthy horses. Allergen-specific IgE serum concentrations were measured in summer seasons of 2008-2015 using a monoclonal anti-IgE antibody. A Northern and Central European allergen panel containing mite, insect, mould and plant pollen allergens, including 15 tests of individual allergens and 5 tests of allergen mixtures was used. The mean allergen-specific IgE concentrations in the atopic and normal horse populations were compared. Among the atopic horses, the strongest positive reactions occurred against the storage mites Tyrophagus putrescentiae and the domestic mite Dermatophagoides farinae. The atopic horses also demonstrated high IgE concentrations against insects, particularly Tabanus sp., the plant pollens colza, cultivated rye and the mould pollen mixture Aspergillus/Penicillium. No horses in the atopic group were IgE-negative. Among all mite, insect, mould and some plant allergen groups the differences in mean specific IgE concentrations between allergic and healthy horses were significant. The mean IgE concentrations for most allergen groups were significantly higher in the atopic horses than in the healthy animals. However, a high incidence of positive reactions was observed in both healthy and allergic horses. Our results showed a high frequency of polysensitization in atopic horses.

Influence of horse breed on transepidermal water loss

Non-invasive methods of skin condition assessment include, among others, the evaluation of transepidermal water loss (TEWL). The aim of the study was to examine whether TEWL values depend on horse breed. The study was conducted on four breeds: "Felin" ponies (FP) (n=16), Polish koniks (PK) (n=15), Polish cold-blooded horses (PcbH) (n=11) and Wielkopolska horses (WH) (n=12). It was found that horse breed influences TEWL values. In the neck region, statistically significant differences were found between PK and FP (p=0.006), and PK and WH (p=0.0005). In the lumbar region, there were statistically significant differences between FP and PK (p=0.0009), FP and PcbH (p=0.0016) as well as between PK and WH (p=0.000037), and PcbH and WH (p=0.0006). In the inguinal region statistically significant differences were found between FP and PK (p=0.0003), FP and PcbH (p=0.0005), PK and WH (p=0.009) and PcbH and WH (p=0.006). In the lip region statistically significant differences were observed between FP and PK (p=0.013) as well as between PK and PcbH (p=0.029) and PK and WH (p=0.009). In the examination of TEWL animal breed should be taken into consideration. The non-significant differences found in three of the examined body regions may suggest that these regions are the most adequate for TEWL assessment.

[Ovaria borderline tumor - fertility-sparing surgery; case report]

The borderline tumors are known as low malignant potential tumors. Usually younger women suffer for them, than by the invasive ovarian carcinoma. They often which to be pregnant. The fertility-sparing surgery is posile but contain higher risk of the new disease on contralateral ovary.

The role of trachelectomy in cervical cancer

Cervical cancer is one of the most common cancers in women worldwide. Because it often affects women of childbearing age (19–45 years), fertility-sparing surgery is an important issue. The article reviews current viable fertility-sparing options with a special focus on trachelectomy, including vaginal radical trachelectomy, abdominal radical trachelectomy and simple trachelectomy. Neoadjuvant chemotherapy is also discussed. Finally, the decision to proceed with fertility-sparing treatment should be a patient-driven process.

[Lymphedema after vulvar cancer surgery. A prospective study]

INTRODUCTION

Prospective detection of postoperative lymphedema of the lower limbs (LLL) in patients after surgery for vulvar cancer using different examination methods and their comparison.

DESIGN

Prospective clinical study.

SETTING

Department of Obstetrics and Gynecology, 2nd Medical Faculty of the Charles University and University Hospital Motol, Prague.

METHODS

Totally 36 women were followed after surgery for vulvar cancer. Due to the radicality of surgery the patients were divided into conservative (sentinel lymph node biopsy) and radical (inguinofemoral lymphadenectomy) group. Lower limbs were preoperatively and 3, 6 and 12 months after surgery assessed for the presence of lymphedema by measuring of circumferences, multifrequency bioelectrical impedance analysis (MFBIA) and subjective evaluation of patients.

RESULTS

The prevalence of lower limb lymphedema 12 months after surgery diagnosed by subjective evaluation reached 19,44%, by circumference measurement 38,89% and with MFBIA 66,67%. The prevalence of lymphedema after inguinofemoral lymphadenectomy diagnosed by circumference measurement was in 12 months after surgery higher (45.83%) than after the conservative surgery (25%). Risk factors were evaluated 12 months after surgery (age, BMI, adjuvant radiotherapy, type of surgery) and none of them were found to be statistically significant for the development of the lower limbs lymphedema.

CONCLUSION

The prevalence of lymphedema significantly depends on the diagnostic method, because they capture lymphedema in its various stages. Due to the high sensitivity MFBIA can be used for the detection of early stages of lymphedema. Preoperative measurement of the lower limbs is important for early detection of postoperative lymphedema.

[Czech version of EORTC QLQ-CX24 questionnaire for patients with cervical cancer]

OBJECTIVE

Translation and validation of the EORTC QLQ-CX24 questionnaire on quality of life into the Czech language and literature.

TYPE OF STUDY

Prospective study.

SETTING

Dept. of Obstetrics and Gynaecology, 2nd Medical Faculty, Charles University and Faculty Hospital Motol, Prague.

METHODS

In concordance with the EORTC guidelines a questionaire for patients with cervical cancer was translated and validated. A group of 14 women who underwent the treatment for cervical cancer filled in the questionaire. T-test was used for the evaluation of the patient's characteristics and the differences in quality of life.

RESULTS

We present a Czech version of the questionaire EORTC QLQ-CX24 and the description how to evaulate it. In comparison of the two treatment groups no statistically significant differences have been found.

CONCLUSION

EORTC QLQ-CX24 is an internationally accepted questionnaire focused on patients with cervical cancer which should be incorporated into the projects dealing with women undergoing treatment for this disease.

[Treatment of recurrent ovarian cancer]

OBJECTIVE

The description of current treatment possibilities in recurrent ovarian cancer.

DESIGN

Review article.

SETTING

Obstetrics and Gynecology Department, Charles University 2nd Medical Faculty and University Hospital Motol, Prague.

METHODS

The review of literature on treatment of recurrent ovarian cancer. Current data on chemotherapy, surgery and targeted biological therapy in recurrent ovarian cancer.

CONCLUSIONS

Chemotherapy is indicated in most cases of recurrent ovarian cancer, surgery does not play an important role. Standard treatment of platinum-sensitive recurrent ovarian cancer is based on platinum combination chemotherapy. Standard treatment of platinum-refractory ovarian cancer represents non-platinum monotherapy. Targeted biological therapy should be still used only in the studies.

[Chemotherapy during pregnancy]

OBJECTIVE

The aim of the study is to summarize current data on chemotherapy administered during pregnancy.

TYPE OF STUDY

Review article.

SETTING

Dept. of Obstetrics and Gynaecology of the Charles University in Prague, 2nd Medical Faculty, University Hospital.

SUBJECT AND METHOD

Pubmed database was searched between the years 1980 and 2009 with the combinations of key words concerning cytostatics, therapy and pregnancy. Cisplatin administration was identified in 38 cases. Eight cases of administration of carboplatin during pregnancy were found with normal neonatal outcome Twenty-one case reports were found on the use of taxanes during pregnancy: 14 on paclitaxel and 7 on docetaxel.

CONCLUSION

Based on the literature the administration of cytostatics during pregnancy can be considered under a close supervision and long-term follow-up in dedicated teams.

Modeling of Coulomb coupling and acoustic wave propagation in LiNbO3

The angular spectrum propagation technique is applied to modeling of wave propagation through piezoelectric media. The calculations of the angular spectrum propagator are based on the relevant equation for the slowness surface resulting from the solution of the Christoffel equation with piezoelectrically stiffened elastic constants. A two-dimensional FFT algorithm is applied in the final field superposition. We concentrate on the case of Coulomb coupling through local electrical point contacts on both the excitation and detection side. To model that case we superpose solutions for acoustic Green's functions of different propagation modes convoluted with equivalent distributed effective sources. Calculated results are in good agreement with the measured ones.

High-dose density chemotherapy followed by simple trachelectomy: full-term pregnancy

We report five patients with early-stage cervical cancer who do not fulfill criteria of fertility-sparing surgery (tumor more than 2 cm in the biggest diameter or infiltrating more than half of stroma). Five patients received three cycles of dose density neoadjuvant chemotherapy (NAC) at a 10-day interval: cisplatin plus ifosfamide in squamous cell cancer or plus doxorubicin in adenocarcinoma with good tolerance. After NAC, they underwent laparoscopic pelvic lymphadenectomy and vaginal simple trachelectomy. Two patients had no residual tumor, two had only microscopic residual disease, and one had macroscopic residual disease. Two women became pregnant 5 and 8 months after surgery, one delivered in term healthy baby and one is now in the second trimester of pregnancy without any complications. NAC followed by fertility-sparing surgery seems to be feasible treatment for women with tumor bigger than 2 cm or infiltrated more than half of the stroma.

[Progression and regression low grade intraepitelial squamous lesions in context of positivity of high risk human papillomavirus]

OBJECTIVE

Evaluation of regression and progression of histologically confirmed low grade squamous intraepithelial lesions (LG SIL) in women under the age of 35 in context of positivity of high risk human papillomavirus (HPV HR). Evaluation of sensitivity of PAP smear and HPV HR test in women with LG SIL.

DESIGN

Prospective study.

SETTING

Department of Obstetrics and Gynecology, Charles University Prague, 2nd Medical Faculty, University Hospital Motol.

PATIENTS AND METHODS

166 women with SIL low or repeated ASC-US PAP smear were included to the study. 1 to 3 punch biopsy under the expert colposcopy and HPV HR test were performed in all women. Follow up were done every 6 month in all women with histologically confirmed LG SIL.

RESULTS

LG SIL was detected in 120 women. Sensitivity of PAP smear was 72.3% and sensitivity of HPV HR test 60.2 % in women with LG SIL. 84 women (70 %) were HPV HR positive. Regression of LG SIL was detected in 20 (23 %) HPV HR positive women and in 18 (50%) HPV HR negative women. This difference is statistically significant (p = 0.0094). Progression of LG SIL was detected in 24 (29 %) HPV HR positive women and in 4 (11%) women HPV HR negative women. This difference is borderline statistically significant (p = 0.058). Progression of LG SIL to the carcinoma in situ or invasive cancer had not been detected during follow up period.

CONCLUSION

PAP smear is a standard for LG SIL detection in women under the age of 35 and HPV HR test is not so important for LG SIL detection in this group of women. HPV HR test could be useful for prediction of the risk of progression, but positivity of HPV HR in LG SIL cannot indicate surgical treatment (conisation) in this cohort of women under the age of 35.

Less radical fertility-sparing surgery than radical trachelectomy in early cervical cancer

The purpose of this pilot study was to determine feasibility and safety of a novel and less radical fertility-preserving surgery; laparoscopic lymphadenectomy with sentinel lymph node identification (SLNI) followed by large cone or simple trachelectomy. Obstetrical and oncologic outcomes were evaluated. Twenty-six patients (6-IA2, 20-IB1) selected on basis of favorable cervical tumor characteristics and the desire to maintain fertility underwent laparoscopic SLNI, frozen section (FS), and a complete pelvic lymphadenectomy as first step of treatment. All of nodes were submitted for microscopic evaluation (sentinel nodes for ultramicrostaging). After a 7-day interval, large cone or simple vaginal trachelectomy was performed in patients with negative nodes. The average of sentinel nodes per side was 1.50 and the average of total nodes was 28.0. Four FS were positive (15.4%). In these cases, Wertheim radical hysterectomy type III was immediately performed. We had no false-negative SLN neither on FS nor on final pathology assessment. Median follow-up was 49 months (18–84). One central recurrence (isthmic part of uterus) was observed 14 months after surgery. This patient was treated with radical chemoradiotherapy, and there was no evidence of the disease 36 months after treatment. Fifteen women planned pregnancy, 11 women became pregnant (15 pregnancies), and 7 women delivered eight children (one in 24 weeks, one in 34 weeks, one in 36 weeks, and five between 37 and 39 weeks). We conclude that lymphatic mapping and SLNI improves safety in this fertility sparing surgery. Large cone or simple trachelectomy combined with laparoscopic pelvic lymphadenectomy can be a feasible method with a high successful pregnancy rate

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.

[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.

[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.

Interference of non-aligned Airy diffraction patterns in transmission acoustic microscopy images of crystals

This paper describes interference effects present in narrow band transmission acoustic microscopy images of crystals that arise from the superposition of pairs of non-aligned but symmetry equivalent Airy diffraction patterns. In the cases we examine, these Airy patterns are associated with folded portions of the slow transverse (ST) sheet of the acoustic wave surface of cubic crystals intersecting in the {110} symmetry planes. Each set of Airy fringes is inclined in the (001) observation plane to its overlapping counterpart, giving rise to curved Moiré-like fringes. Also, because of tilting of the two portions of the wave surface in opposite directions out of the (001) plane, each composite Airy fringe breaks up along its length into a large number of narrow, regularly spaced fringes, in a manner akin to wedge diffraction. We present calculations of these effects in GaAs and Ge, based on the elastodynamic Green's function, , for the infinitely extended anisotropic elastic continuum. A measured time-gated diffraction image is presented for GaAs, which is in good agreement with calculation.

[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.

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.

[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.

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.

[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.

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.

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.

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.

[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.