Analysis of minimal sequences on JC virus VP1 required for capsid assembly

Human JC virus (JCV) belongs to the family of Polyomaviridae. The viral capsid is composed of 72 capsomeres. Five VP1 molecules make up a capsomere structure. To investigate the minimal sequences on JCV VP1 polypeptide required for capsid assembly, the first 12 (Delta N12) and 19 (Delta N19) amino acids at the N-terminus and the last 16 (Delta C16), 17 (Delta C17), and 31 (Delta C31) amino acids at the C-terminus of VP1 were truncated and expressed in E. coli. The VP1 proteins of Delta N12 and Delta C16 were able to self-assemble into a virus-like particle similar to that of wild-type (WT) VP1. However, the mutant proteins of Delta N19, Delta C17, and Delta C31 formed a pentameric capsomere structure as demonstrated by a 10-50% sucrose gradient centrifugation and electron microscopy. These results suggest that the 12 amino-terminal and 16 carboxy-terminal amino acids of VP1 are dispensable for the formation of virus-like particles, and further truncation at either end of VP1 leads to the loss of this property.

Destructive spondyloarthropathy mimicking spondylitis in long-term hemodialysis patients

A 63-year-old man with end-stage renal disease (ESRD) who had been undergoing hemodialysis for 18 years suffered persistent neck pain, progressive quadriparesis, and a deteriorating ataxic gait during the 6 months before admission. A sudden onset of aggravating quadriparesis and an inability to ambulate occurred during his trip to Sydney, Australia, 1 week before this admission. Vertebral tuberculosis osteomyelitis of the C5/6 segment was considered and treated in a hospital there. Findings from cervical magnetic resonance imaging (MRI; low signal intensity on both T1- and T2-weighted images) were diagnostic of destructive spondyloarthropathy (DSA) and distinguishable from spinal osteomyelitis preoperatively. Amyloid masses, mainly composed of B-2 microglobulin, filled in disc and paradiscal ligaments, with adjacent end-plate destruction by cytokine-mediated reactive inflammation, and appeared to be mostly related to the pathogenesis of DSA. The cervical spine, especially C5/6, is the most common site of DSA. Spinal instability and neurologic compression cause the clinical symptoms and signs. Adequate decompression and successful cervical fusion ensure the best therapeutic results.

Potential benefits of restrictions on the transport of teenage passengers by 16 and 17 year old drivers

OBJECTIVES

The presence of passengers is associated with fatal motor vehicle crashes of teenage drivers. A restriction against newly licensed teenage drivers carrying passengers has been included in some, but not all, graduated licensing systems. The purpose of this study was to predict the net effects on all types of road users, including vehicle occupants and non-occupants, of possible prohibitions against 16-17 year old drivers carrying passengers.

METHODS

Two national datasets, a census of fatal crashes and a sample of trips in the United States, were used to compute 1995 road user death rates. Potential effects of restrictions on drivers ages 16-17 carrying passengers younger than 20 were estimated, based on road user death rates and potential choices made by passengers who would have traveled with 16-17 year old drivers if there were no restrictions.

RESULTS

There were 1,181 road user deaths in 1995 involving drivers ages 16-17 whose passengers were all younger than age 20. The predicted number of lives in the United States that would be saved annually ranges from 83 to 493 (corresponding to reductions of 7-42% in road user deaths) for drivers ages 16 and 17 combined. Similar percentages of reductions (8-44%) were predicted solely for 16 year old drivers. Assuming passenger restrictions would apply to all 16 year old drivers and at least one third of 17 year old drivers, an estimated 60-344 fewer deaths per year may occur if restrictions are mandated.

CONCLUSIONS

Restrictions on carrying passengers younger than 20 should be considered for inclusion in graduated licensing systems. Even if fewer than half the drivers obey the restrictions, a substantial reduction in road user deaths would be expected. Further evaluation based on real world experience is needed to confirm their efficacy.

Dietary intake of soybean protein and menstrual cycle length in pre-menopausal Singapore Chinese women

BACKGROUND

Intake of soybean protein was associated with a reduced risk of breast cancer in a case-control study. It has also been demonstrated to increase menstrual cycle length in an experimental setting.

OBJECTIVE

To ascertain whether the association of soybean protein intakes with menstrual cycle length persists in an uncontrolled community setting.

DESIGN

Cross-sectional food frequency dietary survey, menstrual cycle survey and prospective collection of menstrual cycle data.

SETTING

A hospital clinic and a nursing college.

SUBJECTS

Two hundred menstruating women.

RESULTS

An association (P = 0.034) of higher intakes of soybean protein with increased menstrual cycle length, as recorded by self report and by prospectively recording three consecutive cycles, was observed. The risk of menstrual cycle length being greater than the median, when comparing the upper quartile (8.7-35.2 g x day(-1)) of soybean intake and the lowest quartile (0.1-3.3 g x day(-1)) was double, and this approached statistical significance (OR = 2.02, 95% CI = 0.88-4.64 and OR = 1.93, 95% CI = 0.82-4.56 for self-reported cycle length and cycle length as recorded by diary, respectively). In terms of the absolute association with cycle length, subjects in the upper quartile of soybean intake demonstrated a cycle length 1-2 days longer than did subjects in the lowest quartile.

CONCLUSIONS

It is likely that the association between dietary intake of soybean protein and length of menstrual cycle prevails in the community setting. This is shown using both self-reported cycle length and cycle length as recorded in a prospective diary.

A role for p75 neurotrophin receptor in the control of apoptosis-driven hair follicle regression

To examine the mechanisms that underlie the neurotrophin-induced, apoptosis-driven hair follicle involution (catagen), the expression and function of p75 neurotrophin receptor (p75NTR), which is implicated in apoptosis control, were studied during spontaneous catagen development in murine skin. By RT-PCR, high steady-state p75NTR mRNA skin levels were found during the anagen-catagen transition of the hair follicle. By immunohistochemistry, p75NTR alone was strongly expressed in TUNEL+/Bcl2- keratinocytes of the regressing outer root sheath, but both p75NTR and TrkB and/or TrkC were expressed by the nonregressing TUNEL-/Bcl2+ secondary hair germ keratinocytes. To determine whether p75NTR is functionally involved in catagen control, spontaneous catagen development was compared in vivo between p75NTR knockout (-/-) and wild-type mice. There was significant catagen retardation in p75NTR knockout mice as compared to wild-type controls (P<0.05). Instead, transgenic mice-overexpressing NGF (promoter: K14) showed substantial acceleration of catagen (P<0.001). Although NGF, brain-derived neurotrophic factor (BDNF), and neurotrophin 3 (NT-3) accelerated catagen in the organ-cultured skin of C57BL/6 mice, these neurotrophins failed to promote catagen development in the organ-cultured p75NTR null skin. These findings suggest that p75NTR signaling is involved in the control of kerotinocyte apoptosis during catagen and that pharmacological manipulation of p75NTR signaling may prove useful for the treatment of hair disorders that display premature entry into catagen.

Relationships of mortality with the fine and coarse fractions of long-term ambient PM10 concentrations in nonsmokers

In a cohort of 6338 California Seventh-day Adventists, we previously observed for males associations between long-term concentrations of particulate matter (PM) with an aerodynamic diameter less than 10 microm (PM10) and 15-year mortality due to all natural causes (ANC) and lung cancer (LC) listed as underlying causes of death and due to nonmalignant respiratory disease listed as either the underlying or a contributing (CRC) cause of death. The purpose of this analysis was to determine whether these outcomes were more strongly associated with the fine (PM2.5) or the coarse (PM2.5-10) fractions of PM10. For participants who lived near an airport (n=3769), daily PM2.5 concentrations were estimated from airport visibility, and on a monthly basis, PM2.5-10 concentrations were calculated as the differences between PM10 and PM2.5. Associations between ANC, CRC, and LC mortality (1977-1992) and mean PM10, PM2.5, and PM2.5-10 concentrations at study baseline (1973-1977) were assessed using Cox proportional hazards models. Magnitudes of the PM10 associations for the males of this subgroup were similar to those for the males in the entire cohort although not statistically significant due to the smaller numbers. In single-pollutant models, for an interquartile range (IQR) increase in PM10 (29.5 microg/m3), the rate ratios (RRs) and 95% confidence intervals (CI) were 1.15 (0.94, 1.41) for ANC, 1.48 (0.93, 2.34) for CRC, and 1.84 (0.59, 5.67) for LC. For an IQR increase in PM2.5 (24.3 microg/m3), corresponding RRs (95% CI) were 1.22 (0.95, 1.58), 1.64 (0.93, 2.90), and 2.23 (0.56, 8.94), and for an IQR increase in PM2.5-10 (9.7 microg/m3), corresponding RRs (95% CI) were 1.05 (0.92, 1.20), 1.19 (0.88, 1.62), and 1.25 (0.63, 2.49), respectively. When both PM25 and PM2.5-10 were entered into the same model, the PM2.5 estimates remained stable while those of PM2.5-10 decreased. We concluded that previously observed associations of long-term ambient PM10 concentration with mortality for males were best explained by a relationship of mortality with the fine fraction of PM10 rather than with the coarse fraction of PM10.

Gene delivery via polyomavirus major capsid protein VP(1), isolated from recombinant Escherichia coli

In this study we attempted to investigate the feasibility of transferring exogenous DNA into the recipient host via polyomavirus major capsid protein VP(1) pseudocapsids generated from recombinant Escherichia coli, designated PyVP(1,E), both in vitro and in vivo. NIH-3T3 and FR3T3 cells were transfected with pCMV beta and pPyMT-1 plasmid DNA, respectively. In vitro DNA transfection was carried out via Pseudofect- and PyVP(1,E)-mediated methods, or by co-precipitation with calcium phosphate. Expression of beta-galactosidase and PyMT reporter genes was examined by Western-blot analysis. Parallel experiments were performed in vivo by direct injection of pCMV beta and pPyMT-1 plasmid DNA, complexed with PyVP(1,E), into the livers of Wistar rats, followed by Western-blot analysis and histochemical staining. The results obtained from in vitro transfection experiments showed that expression of the reporter genes can be detected in the recipient cells at 48 h post-transfection. PyVP(1,E) was shown to exhibit similarly efficient in vitro DNA transfection properties to Pseudofect, which was obtained from recombinant baculovirus.

Interaction of combined administration of intrathecal morphine with subcutaneous morphine or buprenorphine

AIM

To analyze the mode of interaction of combined administration of intrathecal morphine with subcutaneous morphine or buprenorphine.

METHODS

Different groups of rats were scheduled to undergo administration of intrathecal (ith) morphine, subcutaneous (s.c.) morphine, s.c. buprenorphine, and the combinations of ith morphine with s.c. morphine or buprenorphine in a series of dose ratios. Nociceptive responses of hind paws of each animal were measured by means of "plantar stimulation" test. The test latency was converted to the percent of maximal possible effect (% MPE).

RESULT

Morphine ith, morphine s.c., buprenorphine s.c., as well as combinations in all dose ratios increased the % MPE in a dose-dependent manner. Isobolograms showed that the ED50 points determined for the combinations were plotted significantly left to the theoretical additive line.

CONCLUSION

The combination of morphine ith with either morphine s.c. or buprenorphine s.c. resulted in a synergistic effect. This interaction might be due to the activation of the synergistic antinociceptive mechanisms between supraspinal and spinal levels.

Carrying passengers as a risk factor for crashes fatal to 16- and 17-year-old drivers

CONTEXT

Injuries from motor vehicle crashes are the leading cause of death among teenagers. Carrying passengers has been identified as a possible risk factor for these crashes.

OBJECTIVE

To determine whether the presence of passengers is associated with an increased risk of crashes fatal to 16- and 17-year-old drivers and whether the risk varies by time of day and age and sex of drivers and passengers. DESIGN AND SETTING INCIDENCE: study of data from the Fatality Analysis Reporting System and General Estimates System (1992-1997), as well as the Nationwide Personal Transportation Survey (1995).

SUBJECTS

Drivers aged 16 and 17 years who drove passenger cars, vans, or pickup trucks.

MAIN OUTCOME MEASURE

Driver deaths per 10 million trips by number of passengers, driver age and sex, and time of day; and driver deaths per 1000 crashes by passenger age and sex.

RESULTS

Compared with drivers of the same age without passengers, the relative risk of death per 10 million trips was 1.39 (95% confidence interval [CI], 1.24-1.55) for 16-year-old drivers with 1 passenger, 1.86 (95% CI, 1.56-2.20) for those with 2 passengers, and 2.82 (95% CI, 2.27-3.50) for those with 3 or more passengers. The relative risk of death was 1.48 (95% CI, 1.35-1.62) for 17-year-old drivers with 1 passenger, 2.58 (95% CI, 2.24-2.95) for those with 2 passengers, and 3.07 (95% CI, 2.50-3.77) for those with 3 or more passengers. The risk of death increased significantly for drivers transporting passengers irrespective of the time of day or sex of the driver, although male drivers were at greater risk. Driver deaths per 1000 crashes increased for 16- and 17-year-olds transporting male passengers or passengers younger than 30 years.

CONCLUSION

Our data indicate that the risk of fatal injury for a 16- or 17-year-old driver increases with the number of passengers. This result supports inclusion of restrictions on carrying passengers in graduated licensing systems for young drivers.

Three-dimensional computer-assisted simulation combining facial skeleton with facial morphology for orthognathic surgery

The purpose of this study was to use a 3-dimensional (3D) computer-aided design (CAD) simulation system to plan surgical procedures and predict postoperative changes in orthognathic surgery patients. A computer-generated imaging model was developed by combining a 3D reconstructed cephalometric skeletal image and a laser-scanned facial surface image. Moreover, postoperative data were studied and linked to the simulator model for programming and executing simulated surgical procedures. Interactive editing capabilities allow surgeons to operate CAD surgical simulation, and predicted results can be presented graphically and numerically. The results indicate that the integration of 3D images and CAD techniques have a potential for simulating surgery and providing graphic information to patients in obtaining an informed consent.

Anterior reconstructive spinal surgery with Zielke instrumentation for metastatic malignancies of the spine

From March 1984 to April 1996, 60 consecutive patients with spinal metastasis underwent palliative surgery by anterior corpectomy and Zielke instrumentation. Their ages ranged from 21 to 76 years (mean 54 years). Thirty-two patients had metastasis to the thoracic spine, 20 to the lumbar spine, and 8 had both thoracic and lumbar metastases. The primary malignancies were lung cancer in 12 patients, colorectal cancer in 10, hepatoma in 9, thyroid cancer in 7, breast cancer in 3, and cancers of the stomach, kidney, nasopharynx, long bones, skin, and cervix in 1 patient each. A primary carcinoma was never identified in 13 patients. In the present series, 4 patients died within 1 month, and 56 patients were followed-up. All maintained spinal stability postoperatively. Forty of 52 patients with severe pain obtained significant symptomatic relief for 3 months or more, and 33 of the 46 paralyzed patients gained neural improvement. Sphincter dysfunction became better in 10 patients, and none became worse. We conclude that anterior corpectomy to decompress neural encroachment with instrumental reconstruction to stabilize the collapsed spine is a good adjunctive treatment in these highly selected patients.

A comparative study of human muscle and brain creatine kinases expressed in Escherichia coli

We report the expression of the human muscle (CK-MM) and brain (CK-BB) creatine kinases in Escherichia coli. The proteins have been purified to apparent homogeneity and several of their physical and kinetic properties investigated. In the process, we have conclusively verified the correct DNA sequence of the genes encoding the respective isozymes, and determined the correct primary structure and mass of the gene products. Alignment of the primary sequences of these two enzymes shows 81% sequence identity with each other, and no obvious gross structural differences. However, Western blot analyses demonstrated the general lack of antigenic cross-reactivity between these isozymes. Preliminary kinetic analyses show the K(m) and k(cat) values for the creatine and MgATP substrates are similar to values reported for other isozymes from various tissues and organisms. The human muscle and brain CKs do not, however, exhibit the synergism of substrate binding that is observed, for example, in rabbit muscle creatine kinase.

Identification of a mammalian angiopoietin-related protein expressed specifically in liver

Based on searches of EST databases for signal sequences and amphipathic helices, we have identified and cloned an angiopoietin-like gene, ANGPTL3. Multiple tissue Northern blots show that ANGPTL3 is expressed principally in the liver. ANGPTL3 is expressed early during liver development, and expression is maintained in adult liver. Human ANGPTL3 is a 460-amino-acid polypeptide with the characteristic structure of angiopoietins: a signal peptide, an extended helical domain predicted to form dimeric or trimeric coiled-coils, a short linker peptide, and a globular fibrinogen homology domain (FHD). Murine ANGPTL3 is a 455-acid polypeptide encoded by seven exons on mouse chromosome 4, spanning about 11 kb of DNA. ANGPTL3 contains the four conserved cysteines implicated in the intramolecular disulfide bonds within the FHD, but it does not contain two other cysteines that are found within the FHD of angiopoietins 1, 2, and 4. ANGPTL3 also does not contain the characteristic calcium binding motif found in the other angiopoietins. By radiation hybrid mapping and the use of surrounding genes, human ANGPTL3 maps to the 1p31 region.

[Transformation of common wheat (Triticum aestivum L.) with herbicide-resistant EPSPs gene]

The herbicide-resistant EPSPs (5-enolpyruvylshikimate-3-phosphate synthase) gene was transformed into about 1,000 young spikes and 800 young embryos of wheat variety, Jinghua 1, with gene gun. Thirty-eight and four regenerated plants were obtained respectively screened with glyphosate. All regenerated plants were analysed by PCR and/or Southern blotting. The results indicated that EPSPs gene was integrated stably into the genome of Jinghua 1, and some of the transformants showed fertile. So herbicide-resistant EPSPs gene could be used as selective marker in the transformation of monocotyledon cereal crops, such as wheat.

A role for p75 neurotrophin receptor in the control of hair follicle morphogenesis

During hair follicle (HF) morphogenesis, p75 neurotrophin receptor (p75NTR) reportedly is the first growth factor receptor found to be expressed by those fibroblasts that later develop into the dermal papilla (DP) of the HF. However, the functional role of p75NTR in HF morphogenesis is still unknown. Studying HF development in fetal and neonatal C57BL/6 murine back skin, we show that p75NTR-immunoreactivity (IR) is prominently expressed by DP fibroblasts as well as by skin nerves during the early steps of HF development. In contrast, p75NTR-IR disappears from the DP in the fully developed HF and it is expressed only in the epithelial outer root sheath of the HF. Compared to age-matched wild-type animals, p75NTR knockout (-/-) mice show significant acceleration of HF morphogenesis, and DP fibroblasts of p75NTR knockout mice show reduced proliferative activity in situ, indicating alterations in their transition from proliferation to differentiation. Although no significant differences in the expression of adhesion molecules (NCAM), selected morphogens (TGFbeta-2, HGF/SF, FGF-2, KGF), or their receptors (TGFbetaR-II, m-met, FGFR-1) were seen between DP of p75NTR knockout and wild-type mice, p75NTR mutants showed a prominent upregulation of FGFR-2, a high-affinity receptor for KGF, in both follicular DP and epithelium. Furthermore, the administration of anti-KGF neutralizing antibody significantly inhibited acceleration of HF morphogenesis in p75NTR knockout mice in vivo. These observations suggest that p75NTR plays an important role during HF morphogenesis, functioning as a receptor that negatively controls HF development, most likely via alterations in DP fibroblast proliferation/differentiation and via downregulation of KGF/FGFR-2 signaling in the HF.

Combined spinal epidural for labour analgesia--duration, efficacy and side effects of adding sufentanil or fentanyl to bupivacaine intrathecally vs plain bupivacaine

AIM OF STUDY

The aim of the study was to evaluate the efficacy and side effects of adding sufentanil 10 micrograms, fentanyl 10 micrograms or a control of 1 mL saline to 2.5 mg bupivacaine given intrathecally via combined spinal epidural (CSE) for labour pain relief in the first stage.

METHOD

Sixty ASA I or II patients who requested for epidural analgesia were randomised to three groups. CSE was performed with a 16G Touhy needle and 27G Whitacre needle.

RESULTS

Patients in the sufentanil/bupivacaine group had a significantly longer duration of analgesia (162.9 min +/- 63.4) compared with fentanyl/bupivacaine (110.0 min +/- 44.6) compared with plain bupivacaine (70.0 min +/- 32.1). Pruritus was significant in patients with sufentanil (80%) and fentanyl (47.4%) but did not occur with plain bupivacaine. There was no significant difference in the incidence of nausea or vomiting, hypotension and motor blockade although blood pressures in the sufentanil group were consistently lower than the other two groups. Pain scores were lowest in the sufentanil group. Fetal heart rate changes and Apgar scores were not significantly different between the groups.

CONCLUSION

In combined spinal epidural for labour analgesia, adding sufentanil 10 micrograms to intrathecal bupivacaine 2.5 mg provided fast onset and good analgesia for a longer duration compared with adding fentanyl 10 micrograms and with plain bupivacaine. The main side effect was pruritus. Neonatal outcome was similar.

Acute postoperative aggravation of radiculopathy as a complication of free fat transplantation in lumbar disc surgery: case report

This case report illustrates a rare case of motor weakness caused by a free fat graft herniation. A 40-year-old woman who had undergone surgery for a herniated lumbar intervertebral disc experienced right lower leg weakness. On magnetic resonance image (MRI) a herniated free fat graft was noted. An emergent operation was performed and the herniated fat graft was removed. Postoperatively, the patient recovered well with improvement of the motor weakness. MRI is a good method for diagnosis of fat graft herniation. The mechanisms of this complication have been documented, and the size of the fat graft plays an important role. The methods for prevention of this herniation are also discussed. Although the transplantation of adipose tissue has many advantages, including the prevention of postoperative epidural fibrosis, great care is needed when applying a fat graft intra-operatively. When a postoperative neurologic deficit develops, herniation of the fat graft must be considered. An emergent operation is the treatment of choice for this particular complication.

Three-dimensional virtual imaging of facial skeleton and dental morphologic condition for treatment planning in orthognathic surgery

The improvement of esthetics and function, including the occlusal relationship, needs to be carefully considered in treatment planning for the success of orthognathic surgery. Conventional lateral cephalograms and dental study casts have been used usually for the assessment of skeletal morphologic condition and occlusion, respectively, in planning procedures. However, these traditional techniques do not allow for simultaneous evaluation of the skeletal morphologic condition and the occlusal harmony. A new technique has been developed that combines the conventional clinical diagnostic materials, cephalograms, and dental study casts to produce a 3-dimensional virtual image for routine practice. A 3-dimensional graphic image of dental study casts was generated with a laser surface scanner. A 3-dimensional skeletal image was constructed based on the coordinates of anatomic landmarks registered on frontal and lateral cephalograms. The image of the study cast was then set up with the 3-dimensional skeletal image to create a 3-dimensional dataset of the virtual image. The 3-dimensional virtual image, combining the cephalometric and the dental study cast information, permits simultaneous display of skeletal morphologic condition and occlusal relationship. This 3-dimensional virtual imaging can be helpful in planning orthodontic-surgical treatment and in providing graphic information to the patient. This article describes the technique and outline. A clinical application with this imaging technique is also demonstrated.

Noggin is a mesenchymally derived stimulator of hair-follicle induction

The induction of developmental structures derived from the ectoderm, such as the neural tube or tooth, occurs through neutralization of the inhibitory activity of members of the bone-morphogenetic protein (BMP) family by BMP antagonists. Here we show that, during hair-follicle development, the neural inducer and BMP-neutralizing protein Noggin is expressed in the follicular mesenchyme, that noggin-knockout mice show significant retardation of hair-follicle induction, and that Noggin neutralizes the inhibitory action of BMP-4 and stimulates hair-follicle induction in embryonic skin organ culture. As a crucial mesenchymal signal that stimulates hair-follicle induction, Noggin operates through antagonistic interactions with BMP-4, which result in upregulation of the transcription factor Lef-1 and the cell-adhesion molecule NCAM, as well as through BMP4-independent downregulation of the 75 kD neurotrophin receptor in the developing hair follicle.

Binding and uptake of cationic lipid:pDNA complexes by polarized airway epithelial cells

To better understand the barriers associated with cationic lipid-mediated gene transfer to polarized epithelial cells, Fischer rat thyroid (FRT) cells and polarized normal human bronchial epithelial (NHBE) cells grown on filter supports at an air-liquid interface were used to study the binding and uptake of cationic lipid:plasmid DNA (pDNA) complexes. The efficiencies of binding and uptake of cationic lipid:pDNA complexes by these cell systems were monitored using fluorescence microscopy of fluorescently tagged lipid or pDNA probes. Fluorescent probe bound to the cell surface was differentiated from internalized probe by adding trypan blue, which quenched the fluorescence of bound but not internalized probes. For proliferating cells, binding and internalization of the cationic lipid:pDNA complexes were determined to be efficient. In contrast, little binding or internalization of the complexes was observed using polarized epithelial cells. However, after aspirating a small area of cells from the filter support, virtually all of the cells adjoining this newly formed edge bound and internalized the cationic lipid:pDNA complexes. To determine if their uptake in edge cells was related to the ability of the complexes to access the basolateral membranes of these cells, the binding and uptake of complexes was monitored in polarized NHBE cells that had been pretreated with EGTA or Ca2+-free media, strategies known to disrupt tight junctions. Cells treated in this manner bound and internalized cationic lipid:pDNA complexes efficiently and also expressed significant levels of transgene product. Control cells with intact tight junctions neither bound complexes nor expressed significant transgene product. These data confirm and extend earlier observations that the polarized apical membranes of airway epithelial cells are resistant to transfection by lipid:pDNA complexes. Further, in contrast to previous studies that have shown the entry step of complexes is not an important barrier for COS and HeLa cells, binding and entry of complexes in polarized NHBE cells appear to be rate limiting. These findings suggest that strategies designed to open the tight junctions of polarized epithelial cells may improve gene delivery to these cells for diseases such as cystic fibrosis (CF).

Tri-state median filter for image denoising

In this work, a novel nonlinear filter, called tri-state median (TSM) filter, is proposed for preserving image details while effectively suppressing impulse noise. We incorporate the standard median (SM) filter and the center weighted median (CWM) filter into a noise detection framework to determine whether a pixel is corrupted, before applying filtering unconditionally. Extensive simulation results demonstrate that the proposed filter consistently outperforms other median filters by balancing the tradeoff between noise reduction and detail preservation.

Motor vehicle occupant deaths among Hispanic and black children and teenagers

OBJECTIVE

To determine the risk of motor vehicle occupant deaths per unit of travel for Hispanic, non-Hispanic black, and non-Hispanic white children (aged 5-12 years) and teenagers (aged 13-19 years).

DESIGN

Comparison of 1989 to 1993 motor vehicle occupant death rates of children and teenagers by race, ethnicity, and sex by using data on mortality from the National Center for Health Statistics, travel data from the 1990 Nationwide Personal Transportation Survey, and 1990 US census data.

RESULTS

Among children 5 to 12 years old, race/ ethnicity differences per 100000 persons were unremarkable, but per billion vehicle-miles of travel, the rates were 14 for non-Hispanic blacks, 8 for Hispanics, and 5 for non-Hispanic whites. Among teenagers aged 13 to 19, the rates per 100000 persons were highest for non-Hispanic whites; however, the rates per billion vehicle-miles were 45 for Hispanics, 34 for non-Hispanic blacks, and 30 for non-Hispanic whites. Black and Hispanic male teenagers had substantially higher death rates per billion vehicle-miles of travel than either white male teenagers or female teenagers in any racial/ethnic group.

CONCLUSIONS

Black and Hispanic children and teenagers are at higher risk of dying in motor vehicle crashes when they travel. Greater public health attention is needed to address these increased risks.

Spinal fusion and pedicle screw instrumentation in the treatment of spondylolisthesis over the age of 60

BACKGROUND

Spinal fusion or instrumentation for the treatment of spondylolisthesis in elderly people is still an issue of controversy. The purpose of this study was to assess the clinical results of laminectomy, posterolateral fusion, and pedicle screw instrumentation in patients over age 60.

MATERIALS AND METHODS

From 1993 through 1994, 94 spondylolisthesis patients over age 60 underwent laminectomy, posterolateral fusion and pedicle screw instrumentation. All the patients had follow-up examinations 3 months, 6 months, 1 year and then annually after the operation. At each follow-up visit, the clinical results and complications were evaluated and a radiographic assessment was performed. The follow-up period ranged from 2 to 4 years. At the final follow-up visit, we administered a questionnaire designed for clinical evaluation.

RESULTS

Seventy-five patients (80%) obtained improvement in back pain, 75 patients (80%) got improvement in leg pain, and 65 patients (69%) needed no medications. The average distance the patients were able to walk, at one time was 2.2 km. Sixty-seven patients (71%) could walk more than 500 m at a time. Seventy-four patients (79%) showed solid fusion, 20 patients inadequate fusion, and no psuedoarthrosis was found. Complications were rare.

CONCLUSION

Laminectomy with spinal fusion and instrumentation is a good method for the treatment of spondylolisthesis in elderly people, and it can achieve a satisfactory clinical outcome.

Effects of fish oil on cytokines and immune functions of mice with murine AIDS

The effects of fish oil, which is rich in n-3 fatty acids, on cytokine levels in a murine model of acquired immune deficiency syndrome (AIDS) were studied. Thirty-two C57BL/6 female mice were divided into two dietary groups and fed either a corn oil diet or a fish oil diet. After 4 weeks, each diet group was further divided into two subgroups, and mice in one subgroup were injected i.p. with LP-BM5 murine retrovirus (MAIDS) stock. After 4 weeks, all mice were killed, blood samples were collected, and the spleens and the livers were excised. Splenocytes were isolated immediately and cultured in RPMI-1640 medium and stimulated by either lipopolysaccharide (LPS) or Concanavalin A (ConA) for 24 h. The supernatant was collected for cytokine assays. The results showed that MAIDS infection increased the levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1beta), while fish oil partially prevented this elevation. MAIDS infection depressed interleukin-2 (IL-2) and interferon-gamma (IFNgamma), while fish oil partially prevented the depression of IL-2. In addition, MAIDS infection depressed LPS- and ConA-stimulated cell proliferation, while fish oil partially prevented the depression. The results suggest that fish oil may slow down the progression of murine AIDS by modulating levels of cytokines including TNF-alpha, IL-1beta, and IL-2.

Pyomyositis in childhood: a case report

Pyomyositis is a primary infection of skeletal muscle. We report the case of a previously healthy six-year-old who suffered from pyomyositis in the right lower back. He presented with lower back pain and low-grade fever for one week. After a series of laboratory and imaging studies, the diagnosis of right multifidus muscle pyomyositis with abscess formation was made. The patient recovered rapidly after incision and drainage therapy, accompanied by antibiotic treatment. Methicillin-resistant Staphylococcus aureus was cultured from the abscess discharge. It was strongly suspected that herbal medicines and common cold medication the patient had been prescribed before admission to our hospital produced a masking effect that delayed the diagnosis.

Intrathecal sufentanil as the sole agent in combined spinal-epidural analgesia for the ambulatory parturient

PURPOSE

To compare the effect of a combination of intrathecal (i.t.) sufentanil plus bupivacaine with i.t. sufentanil alone, on the incidence of hypotension and the success of ambulation in parturients.

METHODS

This was a controlled, double-blind prospective trial involving 50 parturients in early labour who had received combined spinal-epidural analgesia (CSE). They were divided equally into two groups; group A received 10 micrograms i.t. sufentanil while group B received i.t. 10 micrograms sufentanil plus 2.5 mg plain bupivacaine. The blood pressure, pain scores, the highest sensory block and the degree of motor blockade were documented over the first 30 min by an unbiased anaesthetist. The ability and the desire to ambulate was studied 30 min after CSE. The side effects were documented throughout labour.

RESULTS

Group B had a higher incidence of hypotension; (12 vs 3: P < 0.01). Fewer parturients in group B could ambulate (19 vs 25: P < 0.05). Group B also had a higher sensory blockade than group A (median T4 VS T7-8: P < 0.01). Of all the 44 parturients who could ambulate, 13 desired not to do so, usually due to sedation.

CONCLUSION

The quality of analgesia in all subjects in the study was excellent. Side effects were more common in the i.t. sufentanil-bupivacaine combination group.

Solitary osteochondroma of the lumbar spine with cord compression: a case report

Solitary osteochondromas are usually of little significance. However, if they are located near neurologic structures, they may cause irritation due to compression. Spinal cord compression is a rare but potentially catastrophic manifestation of solitary osteochondromas. As far as can be ascertained, a solitary osteochondroma in the lumbar region with spinal cord compression has not been reported in Taiwan. This article includes the treatment of an 11-year-old girl with osteochondromas which was complicated by the late development of kyphoscoliosis and a review of the literature.

Creatine kinase: essential arginine residues at the nucleotide binding site identified by chemical modification and high-resolution tandem mass spectrometry

Phenylglyoxal is an arginine-specific reagent that inactivates creatine kinase (CK). Previous results suggest that modification of the dimeric enzyme at a single arginine residue per subunit causes complete inactivation accompanied by the loss of nucleotide binding; the actual site of modification was not identified. Here, high-resolution tandem mass spectrometry (MS/MS) was used to identify three phenylglyoxal-modified Arg residues in monomeric rabbit muscle CK. Electrospray ionizaton Fourier-transform MS of the phenylglyoxal-modified CK that had lost approximately 80% activity identified three species: unmodified, once-modified (+116 Da), and twice-modified (+232 Da) enzyme in a ratio of approximately 1:4:1. MS/MS restricts the derivatized sites to P122-P212 and P283-V332, whereas MS of Lys-C digestions revealed two modified peptides, A266-K297 and G116-K137. The only Arg in A266-K297 is Arg-291 (invariant), whereas MS/MS of modified G116-K137 shows that two of the three sites Arg-129, Arg-131, or Arg-134 (all invariant) can contain the modification. The recently reported x-ray crystal structure for the octameric chicken mitochondrial CK indicates that its nucleotide triphosphate-binding site indeed contains the equivalent of R291, R129, and R131 reported here to be at the active site of rabbit muscle CK.

Early stage nasopharyngeal carcinoma: radiotherapy dose and time factors in tumor control

OBJECTIVE

To evaluate radiotherapy dose and length of treatment in the control of early stage nasopharyngeal carcinoma (NPC) treated with a combination of external radiotherapy and brachytherapy,

MATERIALS & METHODS

We reviewed the records of 133 patients with early stage nasopharyngeal carcinoma (stage I or II, AJC/UICC staging system) who received definitive radiotherapy in Chang Gung Memorial Hospital from 1979 to 1991. The median follow-up time was 7.1 years with a minimum of 2 years. All patients were treated with megavoltage external radiotherapy to the nasopharynx area (63-72 Gy) followed by high dose rate intracavitary brachytherapy (5-16.5 Gy in one to three fractions, spaced 1-2 weeks apart). The median total dose and time of irradiation was 75 Gy (69.8-81.4 Gy) and 11.6 weeks (7.8-20 weeks) respectively. Survival analysis was used to examine the effect of several variables on prognosis.

RESULTS

The 5-year rates were 86.4% for local control, 84.7% for disease free survival, 88.5% for actuarial survival and 84.2% for overall survival. The treatment group (combination of time and dose of irradiation) was the most important prognostic factor according to Cox's proportional hazard model. Patients receiving radiation at a total dose of < or = 75 Gy completed in < 12 weeks showed the best prognosis.

CONCLUSION

Treatment time and total treatment dose are both important factors in treating early stage NPC. Decreasing the total radiation time to < 12 weeks and not exceeding a radiation dose of 75 Gy gave the best results.

Ankle arthrography and chronic lateral ankle instability

Sixty-five ankle arthrograms of the patients who underwent surgical reconstruction for their chronic ankle instability from 1987 to 1995 were studied retrospectively by comparing their operative findings. There were 15 cases (23.1%) with definite positive arthrographic findings. In the remaining 50 cases (76.9%), the arthrograms showed a "tear-drop" extravasation of dye beneath the fibular tip which we called "suspectable positive". Of these all but one, which had normal ligament, proved to correspond to the operative finding. As there was only one false positive finding among our surgical cases with both the "definite" and "suspectable" positive arthrograms, we concluded that ankle arthrography is relatively reliable and may be worth doing even in chronic cases if only for reference. Even when other diagnostic methods are negative, arthrography might help surgeons make surgical decisions in clinical symptomatic cases.

Effect of infection brain edema on NMDA receptor binding in rat brain in vivo

The purpose of this study was to determine the effect of infection brain edema (IBE) in the rat model induced by injecting pertussis bacilli (PB) into the left carotid artery. The specific binding of N-methyl-D-aspartate (NMDA) receptor with [3H] MK-801 was measured in the neuronal membrane of cerebral cortex. The Scatchard plots were performed. The Bmax values were 0.623 +/- 0.082 and 0.606 +/- 0.087 pmol/mg protein in the group that received normal saline (NS) and PB respectively (P < 0.05). The Kd values were 43.1 +/- 4.2 and 30.5 +/- 3.0 nM in the groups NS and PB respectively. The results indicated that the affinity of NMDA receptor was significantly higher in the group PB than group NS, whereas the total number of NMDA receptors had not changed in the IBE model. The increase of affinity of NMDA receptor can be blockaded by MK-801 pretreatment in vivo.

Surgical treatment for pilon fracture of the ankle-open reduction and internal fixation

From 1991 to 1994, 39 ankles of 38 patients underwent surgical open reduction and internal fixation for pilon fractures. These patients included 29 males and 9 females with an average age of 38.6 y/o (range 28 y/o-58 y/o). The follow up and evaluation period averaged 31.7 months (range 22Ms-44Ms), during which time a standing x-ray for arthrosis grading and functional scale was used for clinical evaluation. Complications included 1 case of infection, 1 case of loss reduction, 2 cases of partial skin necrosis and 2 cases of delayed union. Post-traumatic arthritis occurred in 23 ankles (59%) but only 4 ankles of grade 4 arthrosis resulted in poor functional scale and the overall satisfactory rate was 82%. It was found that anatomic reduction, rigid fixation and early motion exercise are important to successful treatment of ankle fractures. Regarding pilon fracture, specifically the severity of fracture pattern and delay of reduction are important problems to overcome to ensure successful results. Therefore, adequate surgical approach for entire view of ankle joint, reduction and fixation of fibula, sufficient bone graft for articular support, intraoperative x-ray check and postoperative immobilization are essential for the achievement of better clinical results.

The efficacy of intrathecal coadministration of morphine and bupivacaine for labor analgesia

BACKGROUND

Intrathecal (i.t.) opioids can provide labor analgesia, but the onset of pain relief is slow. Bupivacaine has the beneficial property of less motor blockade than other local anesthetics. This study retrospectively examined the efficacy of concomitant use of i.t. morphine and bupivacaine for labor pain relief.

METHODS

Fifty five nulliparas who requested analgesia in the active phase (IA group) prior to a cervical dilation 3.9 +/- 0.6 cm and received i.t. morphine 0.5 mg and 0.1% bupivacaine 2.5 mg served as the treatment group, and 88 similar nulliparas who did not request and receive analgesia served as the control group.

RESULTS

The mean onset time of analgesia was 2.6 +/- 0.5 min, the duration was 4-12 h and 93% of parturients did not request additional analgesia after a single injection of i.t. morphine and bupivacaine. The active phase of the first and second stages of labor in the treatment group were significantly longer [318 +/- 214 min vs. 176 +/- 120 min; 74 +/- 29 min vs. 37 +/- 26 min]. Frequency of instrument-assisted vaginal delivery was higher compared with the control group (30.9% vs. 14.1%). However, there were no significant differences in the rate of cesarean section and the Apgar scores of newborns at 1 min and 5 min between the treatment and control group. The major side effects of the treatment group included pruritus (48%), nausea (40%), vomiting (37%), somnolence (27%), shivering (27%), urinary retention (21%), hypotension (15%), and bradycardia (13%). Most of the side effects were mild and could be alleviated by naloxone. Neither post-spinal headache nor respiratory depression was noted.

CONCLUSIONS

Our results showed that a single injection of i.t. morphine and bupivacaine provided rapid onset and effective analgesia with manageable side effects and without major complications. Thus, i.t. morphine and bupivacaine provides an alternative to epidural analgesia for most women in labor.

Salvage operation for neglected ankle fractures

From 1986 to 1993, 49 cases of untreated or poorly treated ankle fractures who received salvage surgery were followed up for an average of 36.4 months. The patients included 31 males & 18 females with an average age of 41.6y/o and the time interval from initial injury to reconstructive surgery average due 17.6 months. They were classified and treated according to their grade of reduction and degree of arthrosis. The surgical methods included arthrotomy & joint debridement, revised open reduction, lower tibial osteotomy and ankle arthrodesis, depending on different individual conditions. After surgery, all cases had symptomatic relief and functional improvement with an average score increased from 26.3 preoperatively to 86.8 at follow up. The goals of ankle fractures is as articular fractures, they are treated by surgical anatomic reduction with rigid fixation as early as possible in order to provide good functional results. Nevertheless they are varied in neglected ankle fractures according to their individual conditions: open reductions were performed on cases with no or little arthritic change even though arthrosis might occur later because, if necessary, future conversion to osteotomy or arthrodesis would be easier. As for late cases with advanced arthritis, ankle arthrodesis were done by compressive arthrodesis with necessary bone graft to secure fusion in an optimal position.

[Differences between effects of hypoxia on rabbit aorta and pulmonary artery]

The difference of morphological injury between rabbit aorta and pulmonary artery was compared after the animal was exposed to the altitude 5 km (PO2 = 10.8 kPa) for 24 h. Hypoxia caused subendothelial edema, increased vacuoles and injured mitochondria and endoplasmic reticulums in both kinds of endothelial cells. The impairment of pulmonary artery was obviously more severe than aorta and its smooth muscle cells were also affected. Forthermore, the exposure increased mitochondria in pulmonary artery endothelial cells. Bubbled with a mixture air of 95% N2-5% CO2 (PO2 = 4 kPa) led to an increase of pulmonary in tension, while hypoxia to the same extent induced aorta relaxation. These results indicate that hypoxia produces the differential effects on these two kinds of vessels, providing a possible explanation for the production of hypoxic pulmonary hypertension.

A CAD/CAM technique for fabricating facial prostheses: a preliminary report

A computer-aided designing and manufacturing (CAD/CAM) technique for clinical fabrication of facial prostheses was developed. Laser surface scanning was applied to acquire three-dimensional imaging data of the patient's facial defect. The three-dimensional imaging data was then transferred to a CAD/CAM interactive program for image processing, which then mathematically designed and produced a model for fabrication of the facial prosthesis. This CAD/CAM technique has the potential to simplify the procedure and decrease the laboratory work required compared to that required for the conventional plaster-cast method. This new technique also provides a novel approach to the fabrication of prostheses for the reconstruction of facial defects. Two alternative three-dimensional modeling processes, laser lithographic modeling and numerically controlled milling modeling, were integrated in this study. The possibilities and current limitations of the techniques are also discussed.

Concurrent 5-fluorouracil, leucovorin, etoposide, cisplatin and radiotherapy for locally advanced non-small cell lung cancer

BACKGROUND

The prognosis of Stage III unresectable non-small cell lung cancer may be improved by concurrent chemoradiotherapy. In this study, we attempted to evaluate the feasibility, tolerance, efficacy and toxicities of the combination of thoracic radiation and chemotherapy with a novel regimen that included 5-fluorouracil, leucovorin, etoposide and cisplatin (the FLEP regimen) in the treatment of this group of patients.

PATIENTS AND METHODS

From July 1995 to September 1996, 20 untreated patients with locally advanced non-small cell lung cancer were enrolled in the study. Radiation at a dose of 44 Gy was initially delivered in daily fractions of 2 Gy 5 days a week to the tumor and mediastinum, followed by a boost to the tumor (20 to 26 Gy according to patients tolerance). Concurrently with thoracic irradiation, patients were treated with chemotherapy consisting of cisplatin at the dose of 60 mg/m2/d for 1 day, etoposide at the dose of 60 mg/m2/d for 2 days, and 5-FU 500 mg/m2/d plus leucovorin 50 mg/d infusion for 48 hours. Cycles of chemotherapy were repeated every 3 weeks for a maximum of 3 cycles.

RESULTS

Seventeen of 20 patients were assessable. The overall response rate was 70.6% (95% confidence interval = 49-92%). No complete response was achieved. The median response duration for all responding patients is not yet estimable, with a range of 3.5 to 15.5+ months. Eleven patients remain progression-free for 4 to 15 months. The median survival for the entire group is not estimable. The major toxicity was esophagitis. Other grade 3 or 4 toxicities were not frequently observed.

CONCLUSION

Combined-modality therapy with FLEP regimen and radiation is a promising treatment with a high response rate and acceptable toxicity for locally advanced non-small cell lung cancer.

Surgical treatment of pathologic fracture of the femur

A retrospective study of the surgical treatment of 32 metastatic lesions of the femur in 30 patients at the Kaohsiung Medical College Hospital was performed from 1987 to 1994. There were 16 women and 14 men with an average age of 61 years. A surgical technique combining internal fixation or prosthesis and methylmethacrylate cement was used in all cases. Adequate pain relief was achieved in thirty-one cases (97 %). Of the entire group, 20 cases (62%) remained ambulatory, 10 cases (31%) were confined to a wheelchair, only two cases had implant failure and one suffered from infection.

Survivorship analysis of DKS instrumentation in the treatment of spondylolisthesis

This retrospective study analyzed the survivorship of DKS instrumentation and the clinical outcomes in 185 patients with spondylolisthesis. These patients were treated with Zielke DKS instrumentation for a mean followup period of 3.5 years. Eight (4.3%) patients had late removal of implants, 25 (14%) had rod breakage, three (1.7%) had screw breakage, and 16 (8.7%) had nut loosening. The survivor rate of DKS instrumentation was 96% within 3 months after operation, 80% at 2 years, and 61% at 5 years after surgery. One hundred sixty-three (88%) patients had solid posterolateral fusion, and 167 (90%) patients had good to excellent results. Adjacent instability developed in 18 (9.7%) patients. Although Zielke DKS instrumentation has a smaller rod and relatively insecure locking system between the rod and screw, it is an effective implant for the treatment of spondylolisthesis.

Acute toxicities and feasibility of altered fractionated radiotherapy in nasopharyngeal carcinoma

BACKGROUND

Altered fractionated radiotherapy (AFR) has been used for many years in the treatment of cancer. Although AFR therapy improves tumor control, it also increases acute radiation toxicities, which may make patients withdraw from treatment. Here, we report on the efficacy of AFR in the treatment of nasopharyngeal cancer (NPC).

METHODS

From September 1993 to October 1994, 68 NPC patients received AFR in Chang Gung Memorial Hospital-Linkou. The efficacy of two types of AFR were studied: (a) Hyperfractionated radiotherapy (HFT) in which irradiation was given twice a day throughout the radiotherapy course with a total radiation dose of 81.6 Gy/68 fractions in 7 weeks; and (b) Concomitant boost radiotherapy (CBT) in which additional concommitant radiotherapy was administered only during the last 2 weeks of the radiotherapy course. The total radiation dose of CBT was 72.3 Gy/42 fractions in 6 weeks. Twenty-six patients received HFT and 42 received CBT.

RESULTS

The percentage of grade 3 complications was 73% in CBT and 65% in HFT. The mean number of treatment days was 57.1 in HFT (median, 53; range 48-63) and 43.9 in CBT (median, 43; range 40-60). No patient withdrew from or prolonged the treatment because of acute radiation toxicities.

CONCLUSION

Our results demonstrated that NPC patients can tolerate HFT and CBT radiotherapy with sufficient psychological support. Further randomized trials will be continued in our institution.

[Role of cytosolic calcium balance on cell injury in cultured bovine aortic endothelial cells during hypoxia and reoxygenation]

Making use of an in vitro model of bovine aortic endothelial cell monolayers, the cell viability and changes of intracellukar calcium concentration of the preparation were submitted to hypoxia with or without reoxygenation. It was shown that the cell viability declined under hypoxia but increased under reoxygenation when the endothelial cells were incubated in calcium-free HBSS, as compared with control HBSS incubation. It was observed that a significant reduction of intracellular calcium from 99 to 69 nmol/L during 2 h of hypoxia, which was further decreased in Ca(2+)-free HBSS medium. After 4 h hypoxia followed by 40 min reoxygenation, [Ca2+]i recovered to the nomal concentration. It is speculated that the calcium homeostasis may be an important condition for cells to carry out normal function and either decrease or increase of [Ca2+]i may injury bovine aortic endothelial cells.

Three cases of fatal pulmonary embolism in obstetrics

We conducted a retrospective analysis of maternal deaths in our hospital from January 1992 to December 1995. Cases of fatal pulmonary embolism were identified and analysed with respect to their past history, antenatal and peripartum progress, clinical presentation and investigation. There were 7 maternal deaths during this period and autopsies were performed in all cases. Pulmonary embolism was the leading cause of maternal mortality, responsible for 3 deaths. The incidence of fatal pulmonary embolism was 4.9 per 100,000 maternities. One case occurred antepartum and 2 occurred postpartum. The antepartum case occurred after a period of immobilisation, and both postpartum cases occurred after emergency Caesarean sections. Dyspnoea and sudden cardiovascular collapse were the commonest presentations. Electrocardiograph and arterial blood gases were abnormal in both patients in whom the tests were performed. Death occurred within 11 hours of presentation of symptoms in all 3 cases. Pulmonary embolism was more common among our population than previously reported, and was the leading cause of maternal mortality in our institution over the last 4 years. Immobilisation and Caesarean section were the major risk factors. Identification of high risk situation, antithrombotic prophylaxis and a high degree of suspicion were the key to reducing the incidence of fatal pulmonary embolism in obstetric patients.

Human methionine synthase. cDNA cloning, gene localization, and expression

Human cDNAs for methionine synthase (5-methyltetrahydrofolate:L-homocysteine S-transmethylase; EC 2.1.1. 13) have been isolated from fetal and adult liver and HepG2 libraries. The cDNAs span 7.2 kilobases (kb) and consist of a 394-base pair upstream untranslated region, a 3795-base pair open reading frame encoding a 1265-residue 140.3-kDa protein, and about 3 kb of 3' region. The deduced protein sequence shares 53 and 63% identity with the Escherichia coli and the presumptive Caenorhabditis elegans proteins, respectively, and contains all residues implicated in B12 binding to the E. coli protein. Several potential polymorphisms and a cryptic splice deletion were detected in the coding region of the cDNAs. A polymorphism that results in a D919G modification in the protein is fairly common in human DNA samples. Northern analyses of poly(A) mRNA indicated two major species of about 8 and 10 kb in human tissues and some minor, partially spliced species. mRNA levels were highest in the pancreas, skeletal muscle, and heart of the adult and in the kidney in the fetus and were low in adult liver. Genomic clones were isolated and the 5' region was analyzed. Exon 1 is preceded by a number of potential promoter sites, including an E box, CAAT boxes, and a GC box, but this region lacks a TATA element. The human methionine synthase gene was localized to chromosome region 1q42.3-43 by in situ hybridization.

Molecular cloning, characterization, and regulation of the human mitochondrial serine hydroxymethyltransferase gene

The human mitochondrial serine hydroxymethyltransferase (mSHMT) gene was isolated, sequenced, and characterized. The 4.5-kilobase gene contains 10 introns and 11 exons, with all splice junctions conforming to the GT/AG rule. The 5' promoter region contains consensus motifs for several regulatory proteins including PEA-3, Sp-1, AP-2, and a CCCTCCC motif common to many genes expressed in liver. Consensus TATA or CAAT sequence motifs are not present, and primer extension and 5'-rapid amplification of cDNA ends studies suggest that transcription initiation occurs at multiple sites. The mitochondrial leader sequence region of the deduced mRNA contains two potential ATG start sites, which are encoded by separate exons. The intervening 891-base pair intron contains consensus promoter elements suggesting that mSHMT may be transcribed from alternate promoters. 5'-Rapid amplification of cDNA ends analysis demonstrated that the first ATG is transcribed in human MCF-7 cells. However, transfection of Chinese hamster ovary cells deficient in mSHMT activity with the human mSHMT gene lacking exon 1 overcame the cell's glycine auxotrophy and restored intracellular glycine concentrations to that observed in wild-type cells, showing that exon 1 is not essential for mSHMT localization or activity and that translation initiation from the second ATG is sufficient for mSHMT import into the mitochondria. Mitochondrial SHMT mRNA levels in MCF-7 cells did not vary during the cell cycle and were not affected by the absence of glycine, serine, folate, thymidylate, or purines from the media.

A fast motion estimation algorithm based on the block sum pyramid

In this correspondence, a fast approach to motion estimation is presented. The algorithm uses the block sum pyramid to eliminate unnecessary search positions. It first constructs the sum pyramid structure of a block. Successive elimination is then performed hierarchically from the top level to the bottom level of the pyramid. Many search positions can be skipped from being considered as the best motion vector and, thus, the search complexity can be reduced. The algorithm can achieve the same estimation accuracy as the full search block matching algorithm with much less computation time.

[Metastatic spine disease: surgical treatment by anterior corpectomy and Ziekel's VDS fixation]

The spine is the common site of skeletal metastases. The goal of surgical treatment of metastatic spine disease is to improve the quality of remaining life, by relief of pain, the preservation or restoration of neurologic function, and reconstruction of the spinal stability. From 1984 through June 1993, 40 consecutive patients underwent surgical treatment by anterior corpectomy, and bone cement with VDS fixation for corporal metastatic diseases. There were 28 men and 12 women. The average age was 53.2 years, range from 21 to 76 years. Twenty-four patients had metastasis to the thoracic spine, 12 to the lumbar spine, and 4 had both thoracic and lumbar metastases. The primary malignancies were lung cancers in 10 cases, colorectal carcinomata in 6, hepatomas in 5, thyroid cancers in 4, cancer of stomach, renal, breast, nasopharynx, long bone, skin, cervical in 1 case respectively. A primary carcinoma was never identified in 8 patients. In the present series, 4 patients died within one month, 36 patients were allowed for follow-up study. Thirty-two patients (89%) attained pain relief. Thirty patients presented with neurologic compromise. After operation, neurologic improvement was noted in 21 (70%). No patient's neurologic function deteriorated secondary to surgical intervention. We conclude that anterior corpectomy to decompress neural encroachment with VDS and cement fixation to stabilize the collapsed spine is an adjunctive treatment to reduce pain and restore the neurologic function in these highly selected patients.