Dose-volume histogram analysis of high dose rate intracavitary brachytherapy for uterine cervix cancer

PURPOSE: We retrospectively analyzed the relationship between dose distribution and local control using a dose-volume histogram (DVH) in patients with cancer of the uterine cervix treated by definitive radiotherapy including intracavitary brachytherapy. METHODS AND MATERIALS: Twenty-five patients with squamous cell carcinoma of the uterine cervix who underwent definitive radiotherapy between August 1987 and April 1994 were selected for the present study. They included 15 patients with local control and 10 patients with local recurrence. In principle, these patients were treated with 50 Gy of external beam pelvic radiotherapy and a point A dose of 24 Gy, in four fractions, of intracavitary brachytherapy. The DVHs of tumor volumes were calculated by superimposing three-dimensional (3D) dose distributions on computed tomography (CT) images taken before brachytherapy. RESULTS: Differential DVHs revealed a tendency for the portion of the total tumor volume to which the delivered dose was low to be larger in patients with local recurrence. The tumor volumes and the absolute dose volumes of which the absorbed dose was less than 24 Gy [DV (< 24 Gy)] were significantly larger in patients with local recurrence than those in local control patients (p = 0.02 and 0.03, respectively). The percent DV (<24 Gy) was not significantly different in the two groups. In patients with larger tumor volume, the absolute DV (<24 Gy) was also larger and a strong linear correlation was noted between them. CONCLUSIONS: The analysis of dose distribution of brachytherapy using DVH was useful to evaluate the quality of dose distribution quantitatively. The absolute dose volume was considered more important than the percent dose volume for evaluation of the clinical outcome. Our study suggested that unfavorable dose distribution for the tumor volume in brachytherapy was one of the reasons of poor local control in patients with large tumor volume.     

Analysis of conserved ambisense sequences within GB virus C

No analysis has been done of the ambisense of GB virus C (GBV-C). When the anti-genomes of 16 reported sequences of GBV-C were analyzed, nucleotide codons 1758 and 1402 within the anti-genome were conserved initiation and stop codons, respectively. Nucleotide sequences were also determined within the same region of 22 GBV-C strains. The anti-genomes of 38 sequences were translated and a consensus sequence was determined. In accordance with the consensus sequence, overlapping peptides were synthesized and used for the detection of anti-synthetic peptide antibodies by ELISA. The positivity of antibodies among sera with GBV-C RNA was significantly higher than among sera without GBV-C RNA (66.7% vs. 15.6%), regardless of the simultaneous presence of hepatitis B surface antigen or antibodies to hepatitis C virus (P < .05). These results indicated that a novel protein associated with GBV-C might be expressed from the ambisense of this virus.     

Immunological studies on PD-1 deficient mice: implication of PD-1 as a negative regulator for B cell responses

PD-1, an Ig superfamily member, contains an immunoreceptor tyrosine-based inhibitory motif in the cytoplasmic tail. It is expressed in a minor fraction of CD4-CD8- normal thymocytes and induced in peripheral lymphocytes following activation. To assess the possible roles of PD-1 in the immune responses, PD-1-deficient (PD-1-/-) mice were generated by a gene-targeting strategy. PD-1-4- mice developed and grew normally. Although the thymus was apparently normal, PD-1-/- mice showed moderate but consistent splenomegaly, which reflected the increased cellularity of both lymphoid and myeloid cells. The proliferative response of B cells by anti-IgM antibodies, but not of T cells by an anti-CD3 (145-2C11) mAb in vitro, was augmented in PD-1-/- mice as compared with control littermates. PD-1-/- mice showed increased serum levels of IgG2b, IgA and most strikingly IgG3, while those of IgM and IgG1 were comparable with control mice. Furthermore, PD-1-/- mice exhibited significantly augmented IgG3 anti-DNP antibody response to a type 2 T-independent antigen, DNP-Ficoll, with comparable IgM and IgG1 antibody responses with littermate controls. In the peritoneal cavity, the B-1 cell population in PD-1-/- mice exhibited significantly reduced expression of CD5, a negative regulator of B-1 cell activation, despite a marginal increase in the number of B-1 cells. Thus, PD-1 was suggested to be involved in the negative regulation for particular aspects of B cell proliferation and differentiation including class switching.     

Identification of Myo3, a second type-II myosin heavy chain in the fission yeast Schizosaccharomyces pombe

We cloned the myo3+ gene of Schizosaccharomyces pombe which encodes a type-II myosin heavy chain. myo3 null cells showed a defect in cytokinesis under certain conditions. Overproduction of Myo3 also showed a defect in cytokinesis. Double mutant analysis indicated that Myo3 genetically interacts with Cdc8 tropomyosin and actin. Myo3 may be implicated in cytokinesis and stabilization of F-actin cables. Moreover, the function of Myo2 can be replaced by overexpressed Myo3. We observed a modest synthetic interaction between Myo2 and Myo3. Thus, Myo2 and Myo3 seem to cooperate in the formation of the F-actin ring in S. pombe.     

Familial type V hyperlipoproteinemia with hyper-remnant-like particle-cholesterol accompanied with apolipoprotein E3/E4 phenotype

From November 1993 to December 1994, a prospective multi-centre phase II clinical trial was done in 137 patients with advanced cancer on China-made pepleomycin (PEP). PEP was effective in patients with cancer of the head and neck, malignant lymphmo and lung cancer, with response rate of 66.7%, 50% and 30%, respectively. The major adverse reactions were fever and mild gastrointestinal reaction. In the controlled study of combination chemotherapy with China-made and Japan-made PEP, the response rates and side effects were similar. The results indicate that China made PEP can be used in lieu of that made in Japan.     

On the nonlinear behavior of the analog phase-locked loop:synchronization

The synchronization, in the presence of time delay, of a nonlinear analog phase-locked loop (PLL) with an analog multiplier as phase detector (PD) and a lag filter is investigated. A nonlinear model for the voltage-controlled oscillator (VCO) is suggested and the sum frequency component at the PD output is taken into account. Simple expressions of the hold-in range of both the main synchronization and the synchronization at the third harmonic are derived. These expressions point out the effect of the time delay and the filter time constant on the hold-in range. Some conclusions of the presented analysis are not anticipated by the PLL classic theory and allow a better understanding of the loop behavior     

Clinical features of small hepatocellular carcinomas as assessed by histologic grades

This paper outlines three important issues in the clinical management of sexually transmitted diseases (STDs) in Papua New Guinea which have, until now, gone unrecognized or been neglected. Suggestions for possible solutions are made. The high prevalence of both chlamydial and trichomonal infections in women cannot be ignored. Both of these infections have been shown to increase the transmission of HIV. The current algorithm for the treatment of vaginal discharges does not include treatment for trichomonal infection in the first instance, yet trichomoniasis has been shown to be the most common STD in community studies both here and elsewhere. Trichomoniasis is usually asymptomatic in men, but still increases the risk of HIV transmission; furthermore, it causes illness in their female partners and thus needs to be treated. The current recommended regimens for the treatment of gonococcal and chlamydial infection are complex due to the number of drugs recommended for gonorrhoea to combat the problem of drug resistance, and the length of therapy for chlamydia. Compliance with such a regimen is likely to be poor, particularly in asymptomatic partners. We need to consider the relative advantages provided by a drug which could be given as a single oral dose for chlamydia, and perhaps for both infections. Azithromycin is one possibility, as it has been shown to be effective for chlamydial infection in numerous studies, and has been found satisfactory for gonorrhoea where local isolates were susceptible. Testing of a small number of isolates from Papua New Guinea has shown that azithromycin may be suitable for use here, but further susceptibility testing needs to be performed. Utilization of services for STDs, particularly by women, is extremely low. This is due to a combination of factors involving limited knowledge of symptomatology and its significance, the asymptomatic nature of many infections, the structure of the services, health worker behaviour, and social attitudes. To address these issues we must make modifications to STD service provision, as well as provide widespread information about the potentially serious consequences of contracting STDs, including both infertility and AIDS. Possible modifications to the services are discussed, and include making routine screening available for women through currently existing services such as family planning and antenatal clinics and considering the possibility of establishing Women's Health Clinics which would provide all primary reproductive health services in an integrated manner.     

Martensitic transformations in NiMnAl β phase alloys

Martensitic transformation characteristics in a wide range of alloy compositions in the NiMnAl system have been investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results indicate that while the NiMnAl alloys with relatively high Al and Mn contents transform martensitically to either the 14M(7R) or the 10M phase with a long-period stacking-order structure, those with low Al or Mn contents transform to the L1₀(3R:2M) structure. TheM _s temperature and thec/a ratio of the L1₀ martensite increase with decreasing Al or Mn content. In the Ni-30Mn-20Al alloy, typical premartensite microstructures, such as needlelike, modulated, and tweed structures, are observed and it is also found that a distorted B2 structure is formed as an intermediate phase prior to transformation to the 10M martensite.     

Rapidly progressive T-cell angiocentric lymphoma with CD56+ phenotype involving bilateral orbits and skin in a patient with anti-HTLV-I antibody

The pressure dependent or myogenic contraction of arterioles is one of the most fundamental control mechanisms of microvascular perfusion. While many experimental observations have been obtained on the myogenic response, no generally accepted biomechanical model has been formulated. A novel biomechanical theory is proposed based on two fundamental assumptions: the arteriolar wall exhibits viscoelastic properties before and during myogenic contractions, and the contraction is achieved by a pressure dependent change of reference length. The formulation of the model and its application to different experimental procedures on microvascular smooth muscle in the literature is presented. The model describes closely a broad spectrum of steady and unsteady pressure dependent diameter variations of arterioles under a pressure dependent stimulus.