Comparison of the outcomes of primary twin pregnancies and twin pregnancies following fetal reduction

High-order multifetal pregnancy is an inevitable consequence of assisted reproduction; and is associated with an increase in perinatal morbidity and mortality. Fetal reduction appears to be a safe and efficacious method for improving obstetric outcome. We made a retrospective study of study population 54 high multiple pregnancy following assisted reproduction that were reduced to twins at Shin Kong Memorial Hospital, Taipei,Taiwan from September 1992 to March 2000. Our study compares the outcome of multifetal pregnancy reduced to twins with the outcome of primary twin pregnancy. Maternal age, birth weight, gestational age at delivery and the incidence of preterm contractions were the only statistically significant differences between the two groups.     

Fetal meconium peritonitis in single and twin pregnancy. Two cases report

We present two cases of fetal meconium peritonitis in a single and twin pregnancy, respectively. The first case diagnosis was made at 30 weeks and was confirmed after delivery of the twins by cesarean section at 37 weeks. The second case diagnosis was made at 31 week and was confirmed at 37 weeks. Meconium peritonitis is a rare prenatal complication that results from intrauterine perforation of small bowel with spillage of sterile meconium into peritoneal cavity. We now report two cases of meconium peritonitis diagnosed at 30 and 31 weeks gestation. Received: 20 March 2001 / Accepted: 13 June 2001     

Rationale for osteotome selection in rhinoplasty

Proper selection of an osteotome for nasal osteotomy is important for minimizing soft tissue trauma. Radiographic analysis of the facial bony lateral wall thickness was performed to suggest a guideline for an appropriate osteotome size for Asians. Facial bone computed tomography (CT) of 100 patients (50 male, 50 female) were studied. The thickness of the facial bony lateral wall at three points along the track of a lateral osteotomy, and two points along the track of a medial osteotomy and intermediate osteotomy were measured. The average bony thickness along the track of a lateral osteotomy was 2.61 +/- 0.66 mm at the low level, 2.75 +/- 0.76 mm at the middle level, and 2.72 +/- 0.53 mm at the high level in subjects. The average bony thickness along the track of an intermediate osteotomy were 1.26 +/- 0.34 mm at the low level, and 1.31 +/- 0.32 mm at the high level in the subjects. The average bony thickness along the track of the medial osteotomy were 2.54 +/- 0.31 mm at the low level, and 2.77 +/- 0.30 mm at the high level in subjects. These results may provide a guideline for choosing an osteotome of appropriate size for the Asian population.     

Early diagnosis of ataxia-telangiectasia using radiosensitivity testing

OBJECTIVES: To utilize radiosensitivity testing to improve early diagnosis of patients with ataxia-telangiectasia (A-T). STUDY DESIGN: We established normal ranges for the colony survival assay (CSA) by testing cells from 104 patients with typical A-T, 29 phenotypic normal patients, and 19 A-T heterozygotes. We also analyzed 61 samples from patients suspected of having A-T and 25 patients with related disorders to compare the CSA with other criteria in the diagnosis of A-T. RESULTS: When cells were irradiated with 1.0 Gy, the mean survival fraction (microSF +/- 1 SD) for patients with A-T was 13.1% +/- 7.2% compared with 50.1% +/- 13.5% for healthy control patients. These data served to define a diagnostic range for the CSA (ie, <21%), a normal range (>36%), and a nondiagnostic intermediate range of 21% to 36%. The mutations of patients with A-T with intermediate radiosensitivity tended to cluster around the functional domains of the ATM gene. CONCLUSIONS: The CSA is a useful adjunctive test for confirming an early clinical diagnosis of A-T. However, CSA is also abnormal in other chromosomal instability and immunodeficiency disorders.     

Purulent pericarditis caused by group G streptococcus as an initial presentation of colon cancer

Bacterial pericarditis has been recognized as a rare disease since the development of antibiotics. Usually, the disease is associated with underlying conditions or a seeding of infection elsewhere to the pericardium. Here we describe a case of group G streptococcal pericarditis as an initial presentation of colon cancer. A 52-yr-old man was admitted because of dyspnea. An electrocardiogram showed a diffuse ST-segment elevation and a two-dimensional echocardiogram showed a large amount of pericardial effusion. A pericardiocentesis was done and purulent fluid was drained. Group G streptococci was cultured in pericardial fluid. The patient was treated with antibiotics and pericardiostomy with saline irrigation. A colonoscopy revealed a small mass with moderately differentiated adenocarcinoma in rectosigmoid colon. He underwent a mucosectomy and was recovered without any complication.     

The effect of reminiscence on the elderly population: a systematic review

Reminiscence therapy is an independent nursing intervention that may be helpful in maintaining or improving self-esteem and life satisfaction for the elderly, but the effects of reminiscence therapy are difficult to measure. For a greater understanding of reminiscence as a nursing therapeutic, this article reviewed the developmental history and theoretical basis of reminiscence and evaluated the empirical evidence concerning the use and effectiveness of reminiscence in the elderly. A lack of consist research findings resulted from selecting different therapeutic goals, different types of reminiscence, different dependent measures, different data collection tools, different sample populations, and small sample size. Future nursing research should redefine the concept and attempt to standardize the measurement of reminiscence and then forge ahead using rigorous research designs to develop a body of knowledge regarding reminiscence.     

Dynamic impact stress analysis of a bileaflet mechanical heart valve

BACKGROUND AND AIMS OF THE STUDY: Mechanical heart valves (MHV) are widely used to replace dysfunctional and failed heart valves. The bileaflet MHV is very popular due to its superior hemodynamics. At present, bileaflet MHVs account for about two-thirds of the prosthetic heart valve market. Since their introduction in 1977, the hemodynamics of bileaflet prostheses has been extensively studied. New technologies used to develop MHV include better design concepts, materials, manufacturing processes, and post-design verification. The study aim was to investigate the dynamic impact stress of a newly designed bileaflet MHV under normal physiological conditions. METHODS: Pro/Engineer was used to generate a 3-D model of the designed valve. ANSYS 5.5 and LS-DYNA were used to calculate stress and deformation of the valve. Due to symmetry, a one-half orifice and one leaflet were modeled using the eight-noded hexahedral elements. When valve leaflets are in the fully closed position, the static contact stress between leaflet and orifice was predicated under typical heart valve closing pressure of 80 mmHg. To study the dynamic effects of the closing valve, LS-DYNA was used to simulate leaflet motion. Typical physiological pressure waveform was employed to initiate this leaflet motion. Two types of valve were investigated: Test valve A (size 19, flat leaflet); and test valve B (size 19, tapered leaflet 1.5 degrees, with the same thickness at pivot as valve A). The non-invasive laser sweeping technique was used to measure leaflet closing velocity in a mock flow test rig. The closing velocity of test valve A was compared by experimental and computed results. The corresponding dynamic contact stress on the leaflet was obtained for different modes of loading, simulated under angular velocity, acceleration, and especially under representative pressure waveform. RESULTS: The experimental closing velocity of test valve A was 1.07 +/- 0.05 m/s; the computed value was 1.130 m/s. During full closure, the leaflets showed a slight rebound, and this was also seen experimentally. For test valve B, the computed closing velocity was 1.039 m/s. In the dynamic impact analysis, the physiological pressure waveform was obtained at a normal heart rate of 70 beats/min from the mock flow test rig. Dynamic stress and displacement of the model valve were calculated as the valve was closing. The time step of calculation was determined by the wave propagation velocity and element size. With an interhinge distance of 4.966 mm based on the geometric design of the valve, maximum dynamic von Mises stress appeared near the hinge of the leaflet (26.92 MPa for valve A; 22.36 MPa for valve B). By varying the position of the hinge/pivoting axis (+/- 10%), an optimized valve geometry could be obtained based on minimal impact stress on the valve leaflet. CONCLUSION: Based on closing velocity comparison of valve A, the calculated model and loading conditions were seen to be reasonable. Computational accuracy was satisfied. The tapering feature of the leaflet is designed especially for minimal impact stress at the leaflet contact areas upon impact with the inner walls of the BMHV. These points provide an optimum structure design for the Nanyang Technological University BMHV.     

Production and characterization of an anti-idiotypic single chain Fv that recognizes an anti-DNA antibody

A well-characterized recombinant anti-idiotype to an anti-DNA antibody can be useful for studies of the regulation of anti-DNA-producing B cells. Using a hybridoma technique, a monoclonal anti-idiotypic antibody, designated O2F3, was obtained, and its scFv gene was constructed. O2F3 single chain Fv (scFv) was produced against an idiotope of a monoclonal anti-DNA antibody, 3D8, that was obtained from an autoimmune-prone mouse, MRL-lpr/lpr. Here we describe the production and in vitro characterization of the O2F3 scFv, and compare it with its parent monoclonal antibody, O2F3 IgM. To characterize O2F3 scFv and O2F3 IgM, we generated recombinant 3D8 fragments, including 3D8 scFv, 3D8 VH, and 3D8 VL, that were used as antigens in several assays. ELISA and Western blot analysis showed that both O2F3 scFv and O2F3 IgM recognized a conformational determinant formed by the association of the variable region heavy and light chains of the 3D8 antibody, suggesting that O2F3 scFv retained a similar binding pattern to its parent O2F3 antibody. The idiotope recognized by O2F3 was shown by competitive ELISA to be outside of the DNA binding site of the 3D8 antibody. This characterized O2F3 scFv could be applied for the regulation of anti-DNA antibody production and the manipulation of recombinant antibody-based proteins to which toxins, enzymes, and chemical agents can be connected.     

Increasing Social Interaction Between General Education High School Students and Their Peers with Mental Retardation

We used a multiple-baseline design across participants to assess the effects of a verbal directive on the social interactions of general education high school students enrolled in a peer buddy program and their peers with mental retardation. General education students were asked to interact as friends with their peers while they engaged in leisure activities. Delivery of the directive was associated with increases in occurrence of social interaction, improvement in quality and reciprocity of interaction, and increases in range of communication behaviors performed by students with mental retardation. In addition, students discussed a greater variety of conversational topics. Findings are discussed with respect to strategies for increasing social interaction among high school students.