Evaluation of cisplatin treatment given concurrently with pulsed irradiation in cisplatin sensitive and resistant human ovarian carcinoma cell lines.

The aim was to investigate the effect of combined treatment of cisplatin with acute or pulsed radiation in human ovarian carcinoma cells sensitive and resistant to cisplatin. Human ovarian cancer cell parental line A2780s and a derivative cisplatin-resistant line A2780cp were given cisplatin treatment before a single acute dose irradiation or concurrently during a pulsed-dose irradiation sequence. Cells were irradiated in the confluent state, trypsinized and plated after treatment. When the combined treatment for cisplatin was given before acute irradiation, the results showed additive to superadditive effects for both cell lines. However, the superadditivity was only significant in the sensitive cell line. For the concomitant treatment of cisplatin during pulsed-dose irradiation the results were additive, except for the highest cisplatin dose in the A2780cp line where subadditivity was observed. The results indicate that the combined treatments could be clinically useful even though the results are mostly not superadditive. However, high-dose cisplatin (3 microg ml(-1)) caused a subadditive effect in the resistant cell lines for pulsed irradiation. Thus, high-dose cisplatin to overcome resistance is not effective. Cisplatin with both acute and pulsed irradiation showed additive effects indicating no advantage of using cisplatin in pulsed irradiation where sublethal damage repair may be greater.

[Radiation sensitivity testing and late neurological complications following radiosurgery for AVM: the use of SF2 from fibroblasts as a predictive factor]. / Radiosensibilité et séquelles neurologiques tardives suite à la radiochirurgie de malformation artérioveineuse : la SF2 comme nouveau facteur prédictif.

PURPOSE: To identify SF2 as a prognostic factor of late complications from radiosurgery in patients treated for AVM. PATIENTS AND METHODS: Five patients with AVM treated in three canadian institutions and who suffered clinically significant neurological sequelaes secondary to radiosurgery were identified. Their fibroblasts were cultured and their radiation sensitivity tested to determine the SF2 for each patient. RESULTS: Patients who developed a neurological complication from radionecrosis, secondary to radiosurgery had an SF2 different than the two control patients with AVM and no complications and also from a group of five cancer patients without late radiation complications (P = 0.005). CONCLUSION: Radiosurgery is an elective procedure. The identification of a subgroup of patients who are radiosensitive and at a higher risk of radiation induced complications can allow the treatment team to reduce the risk of such complications. SF2 as a new predictive factor should be incorporated in predictive models of risk from treatment of AVM by radiosurgery. This work needs to be confirmed in a larger cohort of patients.

Detection of Chlamydia trachomatis in semen of artificial insemination donors by the polymerase chain reaction.

OBJECTIVE: To assess the feasibility of detecting Chlamydia trachomatis in cryopreserved donor semen by a specific, direct polymerase chain reaction (PCR). DESIGN: Cryopreserved donor semen was tested for the presence of C. trachomatis by a specific PCR, directly applied to semen without prior DNA purification. SETTING: Tertiary care fertility center in a teaching hospital and university-based laboratory for molecular pathology. PARTICIPANTS: Cryopreserved semen from 30 donors was investigated. These semen samples had previously given negative results in cell culture for C. trachomatis. Two different ejaculates of each donor, cryopreserved with an interval of 2 years, were retrospectively analyzed. INTERVENTIONS: None. MAIN OUTCOME MEASURE: The presence of C. trachomatis as demonstrated by PCR. RESULTS: In 3 of 30 donors C. trachomatis was detected in both ejaculates, whereas in 2 additional donors only one of the two samples tested positive. Additional samples from 2 positive donors, together with samples from 3 negative donors, were studied more extensively, to test the reproducibility and reliability of PCR results. All ejaculates of the donors, previously positive for C. trachomatis by PCR, indeed appeared to be positive, whereas the samples of the negative donors remained negative. CONCLUSIONS: The direct PCR is a reliable, sensitive, and valuable method for detection of C. trachomatis in semen. The incidence of contamination of donor semen with C. trachomatis in the donor population in this study stresses the need for rigorous screening of donor semen before artificial insemination, preferably using a sensitive method such as the PCR.

General primer polymerase chain reaction in combination with sequence analysis for identification of potentially novel human papillomavirus genotypes in cervical lesions.

We recently described the detection of potentially novel human papillomaviruses (HPV) genotypes (HPV types X [HPV X]) in cervical smears (A. J. C. van den Brule, C. J. L. M. Meijer, V. Bakels, P. Kenemans, and J. M. M. Walboomers, J. Clin. Microbiol. 28:2739-2743, 1990) by using the general primer-mediated polymerase chain reaction method (GP-PCR). In this study, the HPV specificities of GP-PCR products were determined by sequence analyses. M13 bacteriophage clones of PCR products derived from cloned unsequenced HPV genotypes 13, 32, 35, 43, 44, 45, 51, and 56 were subjected to dideoxy sequencing. Analyses of the putative amino acid sequences of these HPV types in addition to published HPV sequence data revealed stretches of highly conserved amino acid residues present in all HPV types, resulting in an HPV amino acid consensus sequence. Subsequently, HPV X-specific PCR products found in premalignant cervical lesions (n = 3), carcinomas in situ (n = 6), and invasive cancer (n = 6) were analyzed for their nucleotide sequences. Comparison of these sequences with published HPV nucleotide sequences and data obtained in this study revealed three HPV type 35, two HPV type 45, one HPV type 51, two HPV type 56, and six unique HPV X sequences, of which three types were present in four cases of carcinomas (in situ). The nucleotide sequences determined appeared to be unique after a data bank search. Furthermore, the sequences of all HPV X isolates matched the HPV amino acid consensus sequence, thus confirming HPV specificity. This study illustrates the power of GP-PCR in combination with sequence analysis to determine HPV specificity and genotyping of PCR products derived from sequenced as well as unsequenced HPVs, including novel, not yet identified HPV types.

Human papillomavirus type 33 in a tonsillar carcinoma generates its putative E7 mRNA via two E6* transcript species which are terminated at different early region poly(A) sites.

Human papillomavirus type 33 (HPV-33)-specific early region transcripts in a tonsillar carcinoma were analyzed by using the RNA polymerase chain reaction method. A total of five cDNA species including species with potential to encode E6*I, E6*II, and E6*III, could be identified. As determined by 3' cDNA end mapping, one E6*I cDNA species was found to utilize a novel early region poly(A) site and was polyadenylated at or near the putative initiation codon of the E1 open reading frame (ORF). Compared with the HPV-16 and HPV-18 E6* mRNAs, the HPV-33 E6*I and E6*II species utilize different splice acceptor sites, the latter being localized within the E7 ORF. Furthermore, HPV-33 E6* mRNAs were found to contain a short overlapping ORF resulting in alternative coding potentials if translation were to start at an internal AUG codon within the E6 region. These results indicate that like HPV-16 and HPV-18, HPV-33 generates E6* mRNAs which may serve as efficient mRNAs for E7. However, HPV-33 has the ability to generate its putative E7 mRNAs by the utilization of two early region poly(A) sites, which offers the possibility of expressing E7 in different ways.

Complications of microwave hyperthermia treatment of psoriasis.

Three healthy men with psoriatic plaques unresponsive to tar, anthralin, and UVB were treated with 2450 MHz microwave heating for 30 minutes at 42 degrees C. Two patients had plaques over bony prominences. Pain developed in both patients, and one had a hypotensive episode during the first treatment. The third patient, whose plaque was greater than 2 cm and was not located over a bony prominence, completed the 5 weeks of biweekly treatments with complete resolution of the plaque and no complications.