Evaluation of the energetic position of the lowest excited singlet state of beta-carotene by NEXAFS and photoemission spectroscopy.

In carotenoids the lowest energetic optical transition belonging to the pi-electron system is forbidden by symmetry, therefore the energetic position of the S(1) (2(1)A(g)) level can hardly be assessed by optical spectroscopy. We introduce a novel experimental approach: For molecules with pi-electron systems the transition C1s-->2p(pi*) from inner-atomic to the lowest unoccupied molecular orbital (LUMO) appears in X-ray absorption near edge spectra (NEXAFS) as an intense, sharp peak a few eV below the carbon K-edge. Whereas the peak position reflects the energy of the first excited singlet state in relation to the ionization potential of the molecule, intensity and width of the transition depend on hybridization and bonding partners of the selected atom. Complementary information can be obtained from ultraviolet photoelectron spectroscopy (UPS): At the low binding energy site of the spectrum a peak related to the highest occupied molecular orbital (HOMO) appears. We have measured NEXAFS and UPS of beta-carotene. Based on these measurements and quantum chemical calculations the HOMO and LUMO energies can be derived.

[Epidermolysis bullosa hereditaria dystrophica mutilans Hallopeau-Siemens--a complex problem]. / Epidermolysis bullosa hereditaria dystrophica mutilans Hallopeau-Siemens--eine komplexe Problematik.

Epidermolysis bullosa hereditaria dystrophica mutilans Hallopeau-Siemens is an autosomal recessive, chronically mutilating disease. Causal therapy is not known. In a five-year-old boy suffering from this disease and having the right hand completely clumped to a fist, syndactyly and contraction release was performed. The wounds healed under the care of the silicone-coated polyamide net dressing Mepitel. Under intensive postoperative physio- and ergotherapeutic care, a major part of his previous hand function could be restored. Complete epithelialization occurred within four weeks. Twelve months after the procedure, the area of the previous lesions was marked by an unexpected mechanical stability. It was very impressive to see the improvement in his psychological well-being and his sense of self-esteem during this period of partial recovery of his hand function.

Human papillomavirus DNA in cervical carcinoma--correlation with clinical data and influence on prognosis.

Human papillomavirus (HPV) is a main factor in cervical carcinogenesis. However, data on the correlation of HPV with clinical features and the prognosis of cervical carcinoma remain controversial. The HPV status (positivity, type, copy number) in unfixed tissue specimens of 205 primary invasive cervical carcinomas was determined by Southern blot hybridization. A correlation with comprehensive clinical and histopathologic data and long-time survival was evaluated. HPV DNA was detected in 73% of the cases; 83% of the HPV-positive tumors contained HPV 16. HPV 16 was predominant among squamous-cell carcinomas (SCC) (p = 0.05). HPV 16 copy number was higher in keratinizing tumors (p < 0.05), and elevated levels of the SCC antigen were more common in patients positive for HPV 16 (p < 0.03). No association was found between the HPV status and 8 other clinical and histopathologic variables. Multivariate analysis after a median follow-up of 73 months demonstrated longer survival for patients with lower clinical stage (p = 0.001) and keratinizing SCC (p = 0.005). Women with HPV-negative tumors had a higher risk of death (RR 1.51; p = 0.07). HPV analysis does not clearly define biologically distinct sub-sets of cervical carcinoma. This underlines the importance of additional factors in cervical carcinogenesis.

Human papillomavirus DNA in locally recurrent cervical cancer.

Ten vaginal and central recurrences of cervical carcinoma were analyzed by Southern blot hybridization under nonstringent and stringent conditions for the presence of human papillomavirus (HPV) type 11, 16, 18, 31, and 35 DNA. Cases judged HPV-negative by this assay were tested with the polymerase chain reaction (PCR) for HPV 16 and 18. All 10 recurrences were HPV-positive. Seven tumors contained HPV 16, one contained HPV 18, one contained HPV 16 and 18, and one contained HPV-related sequences. In three cases, where the corresponding primary tumor could be studied, the identical HPV type was contained. The consistent presence of HPV DNA in local recurrences of invasive cervical carcinoma argues in favor of a role of these viruses also in the maintenance and reappearance of malignancy.

Cognitive and hormonal factors accecting coital frequency.

Sexual behavior of female undergraduates was assessed by daily questionnaries. Of the 24 subjects, 13 were taking oral contraceptives ("pill" subjects) and 11 were using other methods of birth control ("nonpill" subjects), primarily diaphragm or male prophylactic methods. Three main results were obtained: (1) Intercourse rates were lowest during menstruation and highest immediately following menstruation. (2) Self-rated sexual arousal on a given day correlated with the type of heterosexual encouters on that day rather than with period of the menstrual cycle. (3) Pill subjects reported intercourse on more days than nonpill subjects but reported a lower number of intercourse sessions on day with intercourse than nonpill subjects. These results are interpreted within a general framework of sexual behavior which recognizes the sexual behavior of humans as primarily influenced by cultural and cognitive factors. The possibility is discussed that female sexual behavior might also be found to be affected by hormones if more sensitive measures were used.

PIP: Coital frequency was studied in 24 female undergraduate students. 13 of the women were using oral contraceptives (OC), while the remainder used more conventional methods of contraception. The frequency of coitus was lowest during menstruation and highest in the period immediately following menstruation. Self-rated sexual arousal was correlated with the type of sexual attention paid, rather than with a given day during the menstrual cycle. OC users reported coital activity on more days of the cycle than non-pill subjects, but engaged in coitus with less frequency on intercourse days than women using conventional contraception. The results indicate that hormones have very little influence on eroticism and sexual activity in humans. Rather, learning and cultural conditioning are the principal factors guiding human sexual activity.