RESPONSE OF DOSEMETERS IN FIELDS GENERATED BY LASER-ACCELERATED PROTONS.

In laser-driven acceleration, ultra-short and intense laser pulses are focussed on targets to generate beams of ionising radiation. One of the most important issues to be addressed is personal monitoring. While traditional dosemeters were designed primarily for measurements in continuous fields, dosemeters for laser laboratories must be capable of working in pulsed fields of pulse length below 1 ps, in a single-shot regime up to the repetition rate of 1 kHz. Responses of conventional dosemeters (films, polyallyldiglycol carbonate, electronic personal dosemeter) to proton bunches of up to 30 MeV energy produced by South Korean PW laser system at the Advanced Photonics Research Institute, Gwangju Institute of Science and Technology were studied, both by means of Monte Carlo simulations and experimentally.

[Total laparoscopic hysterectomy: current role in gynecology surgery]. / Totální laparoskopická hysterektomie: soucasná role v gynekologické chirurgii.

UNLABELLED: Total laparoscopic hysterectomy (TLH) could be performed in the place of either Total abdominal hysterectomy or Vaginal hysterectomy, thus, there are not any special indications for this procedure. In recent times there has been developed a specially designed uterine manipulator which renders this procedure safe. This manipulator eliminates the necessity of ureteral dissection and also the necessity of incising through the uterosacral ligaments. This last aspect also causes an improvement in support of the vaginal vault. Hysterectomy of this type enables the surgeon to continue laparoscopically in the correction of the enterocoele by means of Moschowitz-McCall culdoplasty. OBJECTIVE: To evaluate indications, results and complications of 27 Total laparoscopic hysterectomies performed from 1/97-6/98. DESIGN: Prospective study. METHODS: 27 patients have undergone TLH (type IV of hysterectomy according to Clermont Ferrand classification). For the surgery a KOH manipulator (RUMI) was used. A pneumooccluder was used in order to prevent the loss of pneumoperitoneum. The most often encountered indications were menorrhagia, cervical dysplasia and fibroid uterus. An additional indication in some of the patients was the presence of enterocoele. Mean age was 42.5 years (35-52). RESULTS: Mean operating time was 92 min. +/- SD. Mean uterine weight 154 g +/- 25 SD. Mean blood loss 140 ml. No complications were noted. Mean length of hospitalization was 3.6 days. CONCLUSIONS: According their early experience the authors are convinced that it is safely possible for a gynaecological surgeon to ad TLH to his surgical armamentarium on condition that, he is well familiar with the performance of laparoscopically assisted vaginal hysterectomy. The early results with TLH are encouraging.

[Preperitoneal laparoscopic retropubic colposuspension in the treatment of stress incontinence: the mesh and tacker technique]. / Preperitoneální laparoskopická retropubická kolposuspenze v lécbe stresové inkontinence: mesh & tacker technika.

UNLABELLED: The Burch procedure has enjoyed in the last decade a favourable status among open surgical repairs for stress urinary incontinence. In the last few years this technique was adapted for endoscopic application. This results in decreased recovery time and diminished postoperative patients discomfort. This endoscopic procedure was further simplified by means of extraperitoneal approach and through the use of Mesh & Tacker technique. This enables a high quality durable colposuspension in significantly shortened operational time. OBJECTIVE: Evaluation of preliminary results and experiences of the above-mentioned new laparoscopic extraperitoneal approach in the treatment of stress incontinence. SETTING: Department of Gynaecology and minimally invasive surgery Na Homolce Hospital. DESIGN: Prospective pilot study. METHODS: The patients with stress incontinence proven clinically and by means of urodynamic investigation (cystometry, stress profilometry and uroflowmetry) were included in the study. The Retzius space was dissected laparoscopically via preperitoneal distention balloon (PDB, Origin Medsystems). Colpofixation to Coopers ligaments was achieved by means of Mesh & Tacker technique, e.g. polypropylen Mesh and aplicator of helicose spirals (Origin Medsystems). RESULTS: In this pilot study of initial 8 patients we may conclude that the above-mentioned method is promising. Of note is shortened operational time (35 min), easy performance without necessity of laparoscopic endosuturing and minimal tissue damage. The small amount of patients and short follow up period would not allow definite conclusions but all the patients are sofar fully continent.

[Radical trachelectomy in the treatment of early cervical carcinoma]. / Radikální trachelektomie v lécbe casného cervikálního karcinomu.

In recent years a new less radical methods in the treatment of early cervical carcinoma has been introduced. The radical trachelectomy with laparoscopic pelvic lymphadenectomy represents one of these options. This procedure is special in that it not only treats the cervical cancer in acceptable oncological fashion but at the same time preserves the fertility potential of the patients. Thus, this surgery represents a midway point in between conisation and radical hysterectomy. Based on our initial experience in this study the technique of radical trachelectomy is analysed in detail and at the same time the current literature on the subject is reviewed. We conclude that after careful selection of the patients this more conservative approach leads to the same results comparable to classical radical surgery.

Response of dosemeters in the radiation field generated by a TW-class laser system.

State-of-the-art laser systems are able to generate ionising radiation of significantly high energies by focusing ultra-short and intense pulses onto targets. Thus, measures ensuring the radiation protection of both working personnel and the general public are required. However, commercially available dosemeters are primarily designed for measurement in continuous fields. Therefore, it is important to explore their response to very short pulses. In this study, the responses of dosemeters in a radiation field generated by iodine high-power and Ti:Sapphire laser systems are examined in proton and electron acceleration experiments. Within these experiments, electron bunches of femtosecond pulse duration and 100-MeV energy and proton bunches with sub-nanosecond pulse duration and energy of several megaelectronvolts were generated in single-shot regimes. Responses of typical detectors (TLD, films and electronic personal dosemeter) were analysed and compared. Further, a first attempt was carried out to characterise the radiation field generated by TW-class laser systems.

Interference patterns generated by a plane-parallel plate.

A simple geometrical theory is developed to evaluate the interference pattern that is generated by a plane-parallel plate illuminated with a monochromatic point source. It is shown that a specific tilt of the plate exists with respect to incident illumination, at which the spatial distribution of the interference fringes becomes uniform. Experimental evaluation of the fringe patterns by superposition moiré techniques supports the theoretical results.

[Early differential diagnosis of tumors of the lesser pelvis using an appropriate combination of noninvasive and invasive methods]. / Vcasná diferenciální diagnostika tumoru malé pánve vhodnou kombinací neinvazívních a invazívních metod.

One hundred and twenty-three female patients were subjected to ultrasound and CT examinations on account of suspected tumours in the area of the lesser pelvis, or to evaluate the postoperative situation. Twenty-five patients were subjected in addition to the mentioned examinations also to angiography of the pelvic arteries. From comparison of the results of the radiodiagnostic examination and the surgical (histological) diagnosis ensues that in patients with a malignant tumour of the ovaries and uterus and with a benign tumour of the uterus the CT examination gives-more satisfactory results than the ultrasound examination. In patients with a benign tumour of the ovaries ultrasonic and CT examinations were approximately equally satisfactory.

Screening of congenital hypothyroidism in newborns in Bohemia and Moravia.

Regular examinations of thyroid function in newborn infants were started in the district of Praha 10 in 1975. Later the incidence of congenital hypothyroidism in Czechoslovakia was assessed in a pilot study including several centers in 1981. As a screening method we used the estimation of total thyroxine (T4) in a dried spot of blood obtained from a heel prick on the fifth day after birth. A total of 45,535 newborns was screened by such method and the incidence was 1:5059 of live born infants. Since 1985 the screening of congenital hypothyroidism has been extended to cover the whole territory of Czechoslovakia. Three screening centers (in Praha, Brno and Banská Bystrica) are responsible for carrying out this screening program. The first screening method employed was the determination of total thyroxine in a dried spot of blood on filter paper as mentioned above. By the end of December 1987, 313,618 samples from newborns have been assayed in Bohemia and Moravia. The incidence of congenital hypothyroidism was found to be 1:5700 of live newborn infants. The treatment of detected cases was started before the end of the first month after birth which ensured normal development of children thus afflicted. When T4 was the first method employed, a relatively high incidence of altered TBG (thyroxine binding globulin) production (1:6400) was encountered, especially in boys.