[Observation on the effect of plasmatrix bone block applied on alveolar horizontal bone augmentation]

A retrospective case series was used to evaluate the effect of plasmatrix bone blocks on bone augmentation at the level of the alveolar ridge. From January 2021 to April 2022, a total of 25 patients who underwent horizontal alveolar ridge level bone augmentation in the Department of Implantology, Wuhan Dazhong Stomatological Hospital were included. Autologous bone chips, deproteinized bovine bone matrix and plasma matrix were used to make plasma matrix bone blocks, combined with absorbable collagen membrane and plasma matrix membrane for guided bone regeneration. Three-dimensional reconstruction was performed on the cone beam CT data before operation and 6 months after operation, and the bone width and alveolar bone volume at 2 and 8 mm from the alveolar crest were measured. The paired t test was used to compare the differences between two time points of the same measurement item. The results showed that compared with preoperative [(5.5±3.4) mm] bone width, the bone width [(9.5±2.5) mm] at 2 mm from the alveolar crest was significantly increased at 6 months after operation (t=3.40, P˂0.001); there was no significant difference in the bone width at the level of 8 mm from the alveolar crest between pre-and 6 months post-operation (t=3.13, P=0.050). The volumes of alveolar bone at 2 and 8 mm from the alveolar crest were (5 114±3 883) and (3 329±2 874) mm3 before operation, respectively, and these increased significantly to (5 999±4 318) and (4 042±3 260) mm3 (t=5.69, P˂0.001; t=5.689, P˂0.001) 6 month post-operation. The results from this study has shown that the use of plasmatrix bone blocks+absorbable collagen membrane+plasma matrix membrane for horizontal bone augmentation in guided bone regeneration has a promising bone augmentation outcome.

The broken circle method: a novel technique that enhances detection of Hill-Sachs lesions on internal rotation shoulder radiographs

AIM

To describe and test a new method that increases the conspicuity of a Hill-Sachs lesion on internal rotation (IR) radiographs.

MATERIALS AND METHODS

This study had institutional review board approval. A retrospective search for patients with a prior shoulder dislocation and a Hill-Sachs lesion documented on magnetic resonance imaging (MRI) was performed over a 10-year period identifying 256 test patients. In Part 1, the IR radiographs from test cases were randomised with controls, and three readers scored them independently for the defect. The readers were then taught the Broken Circle (BC) method and re-scored the radiographs. In Part 2, 15 cases of Hill-Sachs lesions that were missed by all readers in Part 1 were randomised with controls, and were shown to 25 radiology residents before (pre-test) and after (post-test) learning the BC method. A paired t-test was used to compare the differences in sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

In Part 1, the sensitivity increased 19.7% (54.1%-73.8%; p<0.05) and NPV increased 10.8% (62.5%-73.3%; p<0.01). In Part 2, post-test sensitivity for residents increased 16.3% (55.2%-71.5%; p<0.0001), accuracy increased 13.4% (64%-77.4%; p<0.0001), and NPV increased 13.3% (40.8%-54.1%; p<0.0001) independent of the level of training. The change in accuracy was also statistically significant for every individual class.

CONCLUSION

The BC method was an effective technique that facilitated detection of a Hill-Sachs lesion at all levels of training, and was useful as a teaching tool.

Detection and localisation of hip fractures on anteroposterior radiographs with artificial intelligence: proof of concept

AIM

To investigate the feasibility of applying a deep convolutional neural network (CNN) for detection/localisation of acute proximal femoral fractures (APFFs) on hip radiographs.

MATERIALS AND METHODS

This study had institutional review board approval. Radiographs of 307 patients with APFFs and 310 normal patients were identified. A split ratio of 3/1/1 was used to create training, validation, and test datasets. To test the validity of the proposed model, a 20-fold cross-validation was performed. The anonymised images from the test cohort were shown to two groups of radiologists: musculoskeletal radiologists and diagnostic radiology residents. Each reader was asked to assess if there was a fracture and localise it if one was detected. The area under the receiver operator characteristics curve (AUC), sensitivity, and specificity were calculated for the CNN and readers.

RESULTS

The mean AUC was 0.9944 with a standard deviation of 0.0036. Mean sensitivity and specificity for fracture detection was 97.1% (81.5/84) and 96.7% (118/122), respectively. There was good concordance with saliency maps for lesion identification, but sensitivity was lower for characterising location (subcapital/transcervical, 84.1%; basicervical/intertrochanteric, 77%; subtrochanteric, 20%). Musculoskeletal radiologists showed a sensitivity and specificity for fracture detection of 100% and 100% respectively, while residents showed 100% and 96.8%, respectively. For fracture localisation, the performance decreased slightly for human readers.

CONCLUSION

The proposed CNN algorithm showed high accuracy for detection of APFFs, but the performance was lower for fracture localisation. Overall performance of the CNN was lower than that of radiologists, especially in localizing fracture location.

[Evaluation of the intraoperative transesophageal echocardiography for the aortic valve reconstruction]

Objective: To explore the value of the intraoperative transesophageal echocardiography during the aortic valve reconstruction. Methods: The echocardiographic features were retrospectively summarized in 19 patients (male: 15 cases; female: 4 cases; age ranged from 12 to 65 years, mean age: 37.7 years) with aortic valve reconstruction at Beijing Anzhen Hospital between October 2014 and October 2016. Results: The findings of the neo-aortic valve on the transesophageal echocardiography included the slightly thickened and hyperechogenicity of the commission, especially the central coaptation point of the neo-valve. Trace aortic regurgitation was noted in 9 cases after operation, mild aortic regurgitation in 1 case and no aortic regurgitation in 9 cases. The velocity of the aortic valve increased significantly in 2 cases. Compared with pre-operation, the diameter of ascending aorta[(32.7±6.1) mm vs (36.4±6.3) mm, P<0.001]and the inner diameter of left ventricle[(48.3±6.1) mm vs (59.1±7.3) mm, P<0.001]decreased significantly after operation, the coaptation length of aortic valve[(6.6±1.3) mm vs (2.2±0.7) mm, P<0.001]significantly increased than that of pre-operation. The mean immediate velocity after operation (175 cm/s) was slightly higher than that (165 cm/s) of 3-month follow-up after surgery, but with no significant difference (P=0.367). Severe aortic regurgitation was found 15 days after operation in 1 case and 12 months after operation in 2 cases. Conclusion: Intraoperative transesophageal echocardiography is a useful tool to evaluate the result of the aortic valve reconstruction.

Plasma metabolite changes in dairy cows during parturition identified using untargeted metabolomics

The metabolic responses of cows undergo substantial changes during the transition from late pregnancy to early lactation. However, the molecular mechanisms associated with these changes in physiological metabolism have not been clearly elucidated. The objective of this study was to investigate metabolic changes in transition cows from the perspective of plasma metabolites. Plasma samples collected from 24 multiparous dairy cows on approximately d 21 prepartum and immediately postpartum were analyzed using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes. In conjunction with multidimensional statistical methods (principal component analysis and orthogonal partial least squares discriminant analysis), differences in plasma metabolites were identified using the t-test and fold change analysis. Sixty-seven differential metabolites were identified consisting of AA, lipids, saccharides, and nucleotides. The levels of 32 plasma metabolites were significantly higher and those of 35 metabolites significantly lower after parturition than on d 21 prepartum. Pathway analysis indicated that the metabolites that increased from late pregnancy to early lactation were primarily involved in lipid metabolism and energy metabolism, whereas decreased metabolites were related to AA metabolism.

Effect of the Fusarium toxins, zearalenone and deoxynivalenol, on the mouse brain

The aim of this study was to find effects of Fusarium toxins on brain injury in mice. We evaluated the individual and combined effect of the Fusarium toxins zearalenone and deoxynivalenol on the mouse brain. We examined brain weight, protein, antioxidant indicators, and apoptosis. After 3 and 5days of treatment, increased levels of nitric oxide, total nitric oxide synthase, hydroxyl radical scavenging, and malondialdehyde were observed in the treatment groups. This was accompanied by reduced levels of brain protein, superoxide dismutase (apart from the low-dose zearalenone groups), glutathione, glutathione peroxidase activity, and percentage of apoptotic cells. By day 12, most of these indicators had returned to control group levels. The effects of zearalenone and deoxynivalenol were dose-dependent, and were synergistic in combination. Our results suggest that brain function is affected by zearalenone and deoxynivalenol.

The Fusarium toxin zearalenone and deoxynivalenol affect murine splenic antioxidant functions, interferon levels, and T-cell subsets

This study aimed to evaluate the effects of the Fusarium toxin zearalenone (ZEA) and deoxynivalenol (DON) on splenic antioxidant functions, IFN levels, and T-cell subsets in mice. Herein, 360 mice were assigned to nine groups for a 12-day study. Mice were administered an intraperitoneal injection for 4 consecutive days with different concentrations of ZEA alone, DON alone, or ZEA+DON. Spleen and blood samples were collected on days 0, 3, 5, 8, and 12. Mice in each of the experimental groups showed dysreglated splenic antioxidant functions, IFN levels, and T-cell subset frequencies, suggesting that the immune system had been affected. The ZEA+DON-treated groups, especially the group that received a higher concentration of ZEA+DON (Group D2Z2), showed more obvious effects on the dysregulation of splenic antioxidant functions, IFN levels, and T-cell subsets. This finding suggested that DON and ZEA exerted synergistic effects.

Bidirectional and multi-user telerehabilitation system: clinical effect on balance, functional activity, and satisfaction in patients with chronic stroke living in long-term care facilities

Background

The application of internet technology for telerehabilitation in patients with stroke has developed rapidly.

Objective

The current study aimed to evaluate the effect of a bidirectional and multi-user telerehabilitation system on balance and satisfaction in patients with chronic stroke living in long-term care facilities (LTCFs).

Method

This pilot study used a multi-site, blocked randomization design. Twenty-four participants from three LTCFs were recruited, and the participants were randomly assigned into the telerehabilitation (Tele) and conventional therapy (Conv) groups within each LTCF. Tele group received telerehabilitation but the Conv group received conventional therapy with two persons in each group for three sessions per week and for four weeks. The outcome measures included Berg Balance Scale (BBS), Barthel Index (BI), and the telerehabilitation satisfaction of the participants.

Setting

A telerehabilitation system included “therapist end” in a laboratory, and the “client end” in LTCFs. The conventional therapy was conducted in LTCFs.

Results

Training programs conducted for both the Tele and Conv groups showed significant effects within groups on the participant BBS as well as the total and self-care scores of BI. No significant difference between groups could be demonstrated. The satisfaction of participants between the Tele and the Conv groups also did not show significant difference.

Conclusions

This pilot study indicated that the multi-user telerehabilitation program is feasible for improving the balance and functional activity similar to conventional therapy in patients with chronic stroke living in LTCFs.

Influence of different mixing ratios on in-vessel co-composting of sewage sludge with horse stable straw bedding waste: maturity and process evaluation

Composting sewage sludge alone would reduce the decomposition efficiency due to free limited porosity in sludge. To alleviate this, the use of horse stable straw bedding waste (HSB) was evaluated as a co-composting material with sewage sludge in a 10 tonnes day(-1) in-vessel composter for a period of 7 days before curing in a static aeration pile. Sludge was mixed with HSB at 1 : 1.5 (HSL) and 1 : 2.9 (LSL) on a fresh weight basis. After a composting period of 56 days, both mixing ratios demonstrated to be feasible with LSL having a better organic decomposition and a shorter time to reach maturity. The overall decomposition rates were 52.0 and 58.9% (dry weight basis) for HSL and LSL, respectively. In both treatments, temperature in the in-vessel composters could reach 65°C, which was sufficient to remove the pathogens. Although both products were free of pathogens, HSL exhibited a higher ammoniacal nitrogen contents but a lower seed germination index than that of LSL indicating a higher phytotoxicity and a longer curing period would be required. It can be concluded that HSB provided a better composting conditions at a mixing ratio of 1 : 2.9.

Vasorelaxation of Rat Thoracic Aorta Caused by Two Ca2+-Channel Blockers, HA-22 and HA-23

The pharmacological effects of HA-22 (2-(4′methoxyphenylmethyl)-3,4-dimethylpyrano[2,3-c]pyrazol-6(2H)-one) and HA-23 (2-(2′-thienylmethyl)-3,4-dimethylpyrano[2,3-c]pyrazol-6(2H)-one) on rat isolated thoracic aorta have been examined. In high potassium medium (60 Mm), Ca2+ (0·03–3 Mm)-induced vasoconstriction was inhibited by HA-22 and HA-23 (10–100 μg mL−1). Cromakalim-relaxed aortic rings precontracted with 15 Mm but not 60 Mm K+. However, HA-22, HA-23 and verapamil produced a greater relaxation in 60 Mm than in 15 Mm K+-induced contraction. The tonic contractions elicited by KCl (60 Mm) and Bay K 8644 (10−7  m) were also relaxed by the addition of HA-22 and HA-23. The phenylephrine concentration-response curves displayed antagonism by HA-22 and HA-23 (10–100 μg mL−1) in a non-competitive manner. The caffeine (10 Mm)-induced contraction and cAMP or cGMP levels were not affected by HA-22 or HA-23. It is concluded that HA-22 and HA-23 relaxed the rat aorta by suppressing the Ca2+ influx through both voltage-dependent and receptor-operated Ca2+ channels.

Self-incompatibility genes of Brassica oleracea: Expression, isolation, and structure

We demonstrate by in situ hybridization the cell-type-specific expression of transcripts encoded by the self-incompatibility (S) locus of Brassica oleracea. These transcripts are not detected early in stigma development, their expression is switched on in the papillar cells of the stigma surface, and their levels increase in these cells in correlation with the acquisition by the stigma of the self-incompatibility response. By using a probe derived from the untranslated sequences at the 3' end of S cDNA, an S-gene copy expressed in the papillar cells has been isolated from among the multiple S-related copies that occur in the Brassica genome. Structural analysis of this gene shows that it lacks introns. In light of the strict spatial and temporal regulation of S-gene expression in precisely the cells that constitute the barrier to self-pollination, the self-incompatibility response may be viewed as a cell-cell interaction between one pollen grain and one papillar cell.

Protein markers in the microcyst of the posteroventral cochlear nucleus of the gerbil

Microcysts are most evident in the posteroventral and anteroventral cochlear nuclei (PVCN and AVCN) of the Mongolian gerbil. The origin and contents of the microcyst are not elucidated at present. The present study investigated the possible inclusions in the microcyst by employing immunocytochemical labeling to localize the existence of various protein markers. Thirty and 100 microm thick sections were used to substitute and reconstruct between 6 and 20 paraffin serial sections, respectively. In 30-microm-thick slice sections, immunoreactivity of glial fibrillary acidic protein (GFAP-IR), mitochondria inner membrane (MCA-In-IR), S-100 (S-100-IR), serotonin (5-HT-IR), myelin proteolipid protein (PLP-IR) and substance P (SP-IR) abutted on the perimeter of the microcyst. The immunolabeled SP-positive cells were adjacent to the evagination of the microcyst. In 100-microm-thick slice sections, immunoreactivity of nitric oxide synthase (NOS-IR) and somatostatin (SOM-IR) mainly precipitated as flocculent structures in the small to medium-sized microcysts. 5-HT-IR also precipitated as an elongated flocculent stalk adjacent to the large microcyst or randomly distributed in the neuropil. The findings suggest that GFAP, MCA-In, S-100, 5-HT, PLP, SP, NOS and SOM may be involved in modulating the physiological functions and maintaining micro-environmental homeostasis of the microcyst in the cochlear nucleus of the gerbil.

Cerebral response to patient's own name in the vegetative and minimally conscious states

BACKGROUND

A challenge in the management of severely brain-damaged patients with altered states of consciousness is the differential diagnosis between the vegetative state (VS) and the minimally conscious state (MCS), especially for the gray zone separating these clinical entities.

OBJECTIVE

To evaluate the differences in brain activation in response to presentation of the patient's own name spoken by a familiar voice (SON-FV) in patients with VS and MCS.

METHODS

By using fMRI, we prospectively studied residual cerebral activation to SON-FV in seven patients with VS and four with MCS. Behavioral evaluation was performed by means of standardized testing up to 3 months post-fMRI.

RESULTS

Two patients with VS failed to show any significant cerebral activation. Three patients with VS showed SON-FV induced activation within the primary auditory cortex. Finally, two patients with VS and all four patients with MCS not only showed activation in primary auditory cortex but also in hierarchically higher order associative temporal areas. These two patients with VS showing the most widespread activation subsequently showed clinical improvement to MCS observed 3 months after their fMRI scan.

CONCLUSION

The cerebral responses to patient's own name spoken by a familiar voice as measured by fMRI might be a useful tool to preclinically distinguish minimally conscious state-like cognitive processing in some patients behaviorally classified as vegetative.

Treadmill Training Effects in Different Age Groups following Middle Cerebral Artery Occlusion in Rats

BACKGROUND

Despite the increased understanding of treadmill training on stroke patients, its effects on different age groups are not clearly known. The present study presents such effects through a model of cerebral ischemia on young and old groups of rats.

OBJECTIVES

To investigate the effect of treadmill training on young and old rats after cerebral ischemia caused by middle cerebral artery occlusion (MCAO).

METHODS

Forty old (22-24 months of age) and 32 young (3-4 months of age) rats underwent the MCAO procedure for 60 min. Rats that survived the procedure were randomly assigned to a 1- or a 2-week treadmill training group, or a time-matched control group (n=6-8 for each group). The infarct volume was compared between the treadmill training and the control groups for both the young and old rats at 1 or 2 weeks.

RESULTS

After treadmill training for 1 week, the mean infarct volume was 7.26+/-0.49 and 9.51+/-0.84% for the young and old rats, respectively. The 1-week treadmill training effect was significant in the young rats (p=0.0207) but not in the old rats (p=0.0840). The mean infarct volume was 6.84+/-0.51 and 7.63+/-0.52% for the young and old rats, respectively, after the 2-week treadmill training. Both the young and old rat groups demonstrated a significant reduction in the infarct volume compared with that of the control group (p=0.021 for the young group and p=0.039 for the old group) after 2 weeks of treadmill training.

CONCLUSION

The present findings clearly demonstrate the different training effects of locomotor activity in reducing ischemic infarction in young and old rats. The delayed reduction in ischemic infarction in old rats was notable and may be attributable to the slow response of angiogenic and neurogenic mechanisms in the old rats.

Elevation of plasma and cerebrospinal fluid osteopontin levels in patients with atypical teratoid/rhabdoid tumor

Osteopontin, a cancer metastasis-associated gene, is specifically up-regulated in central nervous system (CNS) atypical teratoid/rhabdoid tumor (AT/RT), but its biological behavior in the progression of CNS AT/RT has never been studied. We obtained plasma, cerebrospinal fluid (CSF), and brain tissue specimens from lobectomy or hemispherectomy samples from 39 patients (medulloblastoma, 16; AT/RT, 8; epilepsy, 6; hydrocephalus, 9). By enzyme-linked immunosorbent assay, the median osteopontin levels in plasma and CSF in AT/RT (852.0 and 1,175.0 ng/mL, respectively) were significantly higher than in medulloblastoma (492.5 and 524.5 ng/mL, respectively) and hydrocephalus and epilepsy (208.0 and 168.0 ng/mL, respectively) (P < .05). The results of real-time reverse transcriptase-polymerase chain reaction and immunohistochemical analysis demonstrated that osteopontin expression in AT/RT (n = 5) was significantly higher than in medulloblastoma (n = 8) samples. The differences in osteopontin expression in plasma, CSF, and tumor samples in AT/RT and medulloblastoma correlated with survival differences. In 5 patients with AT/RT, plasma osteopontin levels decreased after treatment but increased with relapse. Osteopontin might be a potential marker to aid in identifying AT/RT recurrence.

Treadmill training effects on neurological outcome after middle cerebral artery occlusion in rats

BACKGROUND

Treadmill training is used for promoting rhythmical vigorous walking and for task-related training in patients with stroke. The neurological impact of treadmill training has not been established. The present investigation is aimed at (1) examining neurological changes over a four-week period after middle cerebral artery occlusion (MCAO) in rats and (2) assessing the impact of one-week, two-week and four-week treadmill training in MCAO rats.

METHODS

Male Sprague-Dawley rats were subjected to 60-minute right MCAO. All rats were randomly assigned to one of seven groups. Infarct volume and neurological score were measured.

RESULTS

Rats sacrificed 24 hours post MCAO had the largest infarct volumes (171.4 +/- 14.4 mm3) and the highest neurological score (median: 2, range: 1-3). We noted that without treadmill training, infarct sizes and neurological score diminished with time. Treadmill training for at least one week further reduced infarct volume and significantly improved neurologic function in MCAO rats.

CONCLUSION

Treadmill training after focal cerebral ischemia significantly improves neurological outcome in MCAO rats. Treadmill training may be beneficial for ischemic brain recovery.

Confinement-induced order of tethered alkyl chains at the water/vapor interface

Packing of tethered alkyl chains in Langmuir monolayers of a hairy-rod polypeptide poly[gamma-4-(n-hexadecyloxy)benzyl alpha,L-glutamate] on water has been studied by x-ray scattering measurements at room temperature. The rods lie parallel to the surface while the alkyl side chains segregate toward the vapor. Results indicate that the herringbone order of the alkyl chains is established initially by one-dimensionally confined chains between aligned rods and grows laterally with compression.

Thermal and structural properties of biologically derived monodisperse hairy-rod polymers

Monodisperse derivatives of poly(gamma-4-(hexadecyloxy)benzyl alpha,L-glutamate) (PHBG-X, X = 3 or 4) with backbone sequence GluAsp(Glu17Asp)xGluGlu were prepared by reaction of 4-(hexadecyloxy)phenyldiazomethane with the corresponding monodisperse poly(alpha,L-glutamate) (PLGA) derivatives (PLGA-X, X = 3 or 4). PHBG-3 and -4 exhibited strong endotherms near 45 degrees C and weak endotherms near 86 degrees C when analyzed by differential scanning calorimetry. X-ray diffraction suggested that these polymers aggregate to form layerlike solid structures at room temperature, with extended alkyl side chains forming paraffinlike crystallites. Most of the side chain order disappears at the first melting transition; however, the layerlike structure remains. Both polymers are isotropic above the second melting transition; no ordered melts were observed at higher temperatures, possibly due to the small aspect ratios of PHBG-3 and -4. In contrast, polydisperse poly(gamma-4-(hexadecyloxy)benzyl alpha,L-glutamate) (PDI = 1.2, DP = 98) (PHBG-P1), prepared from commercial PLGA, formed liquid crystalline (LC) phases between 97 and 105 degrees C.

The impact of sea water flushing on biological nitrification-denitrification activated sludge sewage treatment process

The process performance of the two largest activated sludge processes in Hong Kong, the Sha Tin and the Tai Po Sewage Treatment Works (STW), deteriorated in the initial period after the introduction of seawater flushing in 1995 and 1996, respectively. High effluent ammonia nitrogen (NH4-N) and total suspended solids (TSS) in excess of the discharge standards resulted from incomplete nitrification and changes in floc characteristics. A desktop study on the inhibitory effects of salinity, particularly on nitrification, was subsequently conducted using the Tai Po STW operating data. To assist the upgrade of the Sha Tin STW a five-month extensive bench-scale investigation on a simple but flexible modified Ludzack-Ettinger configuration with bio-selector was conducted to quantify the inhibitory effects due to the saline concentration. The Sha Tin STW upgrade consists of restoration of its original design capacity (conventional process) of 205,000 m3/day from its currently much reduced capacity as a Bardenpho process. Only the volume of the existing biological process and clarifier is to be utilized. The saline concentration ranges from 3,500 up to 6,500 mg Cl-/L, both daily and seasonally. High and greatly fluctuating saline concentrations have been known to inhibit nitrification. Design consideration should also be given to the peak daily and seasonal TKN loading of up to three times the average. Although the nitrifiers maximum specific growth rate was significantly reduced to a low 0.25 day(-1), the inhibition was considered to be tolerable with effluent NH4-N and NO3-N consistently at < 1 and < 6 mg/L. The bio-selector was demonstrated to be efficient in control of sludge foaming and bulking with SVI consistently < or = 125 mL/g. Results from the IAWO Model No. 1 and the hydraulic model of the secondary clarifiers allowed overall process capacity maximization. With an anoxic mass fraction of 25-30%, operating sludge age of 9-14 days and SVI < or = 125 mL/g, both the design requirements and the effluent discharge standards could be met. Without these investigations, an unnecessarily large reaction basin and secondary clarifier volume, and hence capital investment, would have resulted.

Protective effects of treadmill training on infarction in rats

This study was undertaken to determine the protective effects of treadmill training on brain ischemic lesions caused by middle cerebral artery (MCA) occlusion in male rats. Rats were divided into four groups: control, 1-week treadmill pre-training, 2-week treadmill pre-training, and 4-week treadmill pre-training. Cerebral infarction was induced by MCA occlusion for 60 min, followed by reperfusion. After 24 h, rats were killed and brain slices were then stained to assess lesion size. Treadmill training at least for 2 weeks can reduce the infarction size and edema caused by MCA occlusion (P<0.01). The present study provides evidence that treadmill training reduces ischemic brain damage in an animal model of cerebral ischemia.

Factors associated with use of preventive dental and health services among U.S. adolescents

PURPOSE

To examine adolescents' use of preventive medical and dental services and its relationship to demographic characteristics and other variables reflecting access to and need for care.

METHODS

Self- and parent-reported data from a sample of 5644 adolescents aged 11 to 21 years from the National Longitudinal Study of Adolescent Health (Add Health). Variables studied include the influence of both the adolescents' demographic and socioeconomic characteristics (age, race/ethnicity, place of birth, acculturation, insurance status, and perception of health), as well as those of their parents (race/ethnicity, income, level of education, place of birth) on their lifetime use and use within the past year of medical and dental services. Bivariate and logistic regression analyses were conducted using SAS and SUDAAN.

RESULTS

Approximately 32% of respondents had not had a physical examination in the year before the survey, and the same percentage had not had a dental examination. Approximately 2% reported never having had either a physical or a dental examination. Logistic regression reveals that lack of insurance, low family income, and low parental education level are significantly associated with the lack of preventive medical care. Lack of an annual dental visit was associated with male gender; black, Hispanic, or mixed race/ethnicity; and lack of insurance. Never having had a dental visit was the only dependent variable found to be associated with place of birth.

CONCLUSIONS

Health insurance and family income are most consistently related to adolescents' use of preventive medical and dental care. However, the relationship between lack of dental care and place of birth emphasizes the need to improve access to dental services for immigrant teens. These findings are particularly relevant as states design systems of care for adolescents under the State Children's Health Insurance Program.

Prenatal care use among selected Asian American groups

OBJECTIVES

This study examined the predictors of 3 patterns of prenatal care use (no care, late initiation of care, and inadequate use after early initiation) for 4 Asian American ethnic groups in the United States.

METHODS

Single live births to US resident mothers of Chinese, Japanese, Korean, and Vietnamese ancestry (n = 273 604) were selected from the 1992-1996 US natality files. Logistic regression was used to analyze the effects of maternal characteristics on the 3 use measures.

RESULTS

Korean Americans and Vietnamese Americans had the lowest levels of prenatal care use. Young or single motherhood, high parity for age, and low educational attainment were the main risk factors for low use.

CONCLUSIONS

Considerable variability exists in prenatal care use among Asian American ethnic groups.

The health status of rural and urban ambulatory elderly in Taipei County

BACKGROUND

To study the differences in the health status of rural and urban ambulatory elderly in Taipei County.

METHOD

Non-compulsory general health check-up for elderly people over 65 years old in rural and urban areas. The content of the health examination included past medical history, health behavior, physical examination, laboratory examination, electrocardiogram and x-ray. Chi square test, t-test and logistic regression were applied for analysis. Risk factors relating to the cardiovascular system were included in the study. Gender differences affecting the prevalence of diseases and health behavior were also considered in the analysis.

RESULTS

Significantly higher proportions of the rural elderly men smoked, drank alcohol, and had hypertension and impaired renal function. On the other hand, higher proportions of rural elderly women were obese and had diabetes, hypertension and renal impairment. The mean plasma glucose level of newly-diagnosed diabetic patients in the rural area was significantly higher than that in the urban area (p < 0.05). Diabetes, obesity, hypercholesterolemia and smoking were significantly associated with hypertension. The odds ratio for hypertension between rural and urban areas was 1.45 (p < 0.0001). The cardiovascular risk-rating score of rural elderly was statistically higher than that of urban elderly (p < 0.001).

CONCLUSION

There were some minor differences in health status between urban and rural elderly. Health promotion should be varied according to the needs of various communities and various risk groups. Further studies should concentrate on prospective cohort research with well-defined determinants to evaluate whether cost-effective biopsychosocial intervention is necessary.

An improved tripod amphiphile for membrane protein solubilization

Intrinsic membrane proteins represent a large fraction of the proteins produced by living organisms and perform many crucial functions. Structural and functional characterization of membrane proteins generally requires that they be extracted from the native lipid bilayer and solubilized with a small synthetic amphiphile, for example, a detergent. We describe the development of a small molecule with a distinctive amphiphilic architecture, a "tripod amphiphile," that solubilizes both bacteriorhodopsin (BR) and bovine rhodopsin (Rho). The polar portion of this amphiphile contains an amide and an amine-oxide; small variations in this polar segment are found to have profound effects on protein solubilization properties. The optimal tripod amphiphile extracts both BR and Rho from the native membrane environments and maintains each protein in a monomeric native-like form for several weeks after delipidation. Tripod amphiphiles are designed to display greater conformational rigidity than conventional detergents, with the long-range goal of promoting membrane protein crystallization. The results reported here represent an important step toward that ultimate goal.

Problem-based, small-group tutorial learning in clinical neurology for second-year medical students

BACKGROUND

Problem-based learning (PBL) in small-group tutorials has been a trend in medical education. Chinese students are known to be reserved and passive; thus, they may not be adaptable to PBL. Neuroanatomy, important to clinical neurology, is difficult to learn. We incorporated clinical neurology with PBL, complementary to the traditional neuroanatomy curriculum, to evaluate the feasibility of PBL for Chinese students in Taiwan.

METHODS

Forty-two second-year medical students and seven tutors participated in the clinical neurology PBL small-group tutorials. Twelve case reports were discussed weekly beginning in February, 1999. Each case was designed to meet the progressive curriculum of the neuroanatomy course. The tutors evaluated the students by the degree of their preparation, participation, key-point comprehension and interaction. All tutors and students filled out questionnaires at the end of each session.

RESULTS

The majority of the students and tutors agreed that the case materials were clearly written. Ninety percent of the students agreed that the case materials matched the traditional content of neuroanatomy. Eighty-five percent of students and 71% of tutors were satisfied and found the class rewarding. Ninety-one percent of students and 74% of tutors were in favor of PBL being continued.

CONCLUSIONS

This preliminary PBL, small-group tutorial learning in clinical neurology showed satisfactory results and was, indeed, complementary to a traditional neuroanatomy course. The students, as early as during the second year of their medical school education, were able to learn through the PBL. More integration of basic and clinical sciences by PBL may be considered in future curricula designs.

Prepregnancy body mass index and pregnancy weight gain: associations with preterm delivery. The NMIHS Collaborative Study Group

OBJECTIVE

To examine associations between rate of pregnancy weight gain and preterm delivery among women of varying prepregnancy body mass indices (BMI).

METHODS

Subjects were 3511 mother-infant pairs from the 1988 National Maternal and Infant Health Survey. Prenatal weight measured between 14 and 28 weeks' gestation was used to calculate rate of pregnancy weight gain for each woman. Weight gain (lb/week) was categorized as low (under 0.5), average (0.5-1.5), or high (above 1.5). Prepregnancy BMI was calculated as weight divided by height in (kg/m(2)) and categorized as low (under 19.8), average (19.8-26.0), and high (above 26). Delivery before 37 weeks' gestation was considered preterm. Associations between BMI, weight gain, and preterm delivery were examined before and after exclusion of medically indicated preterm deliveries and pregnancies complicated by maternal medical conditions potentially related to weight gain or fetal growth restriction. Associations were expressed as odds ratios (OR) adjusted for several potential confounding factors.

RESULTS

Women with low pregnancy weight gain were at increased risk of preterm delivery. The magnitude of risk varied according to a woman's prepregnancy BMI. After all exclusions and adjustments for confounders, ORs, and 95% confidence intervals (CI) for low pregnancy weight gain were 6.7 (1.1, 40.6) for underweight women, 3.6 (1.6, 8.0) for average-weight women, and 1.6 (0.7, 3.5) for overweight women compared with average-weight women with average pregnancy weight gain.

CONCLUSIONS

Low weight gain in pregnancy was associated with increased risk of preterm delivery, particularly if women were underweight or of average weight before pregnancy.

Cloning and functional characterization of a constitutively expressed nitrate transporter gene, OsNRT1, from rice

Elucidating how rice (Oryza sativa) takes up nitrate at the molecular level could help improve the low recovery rate (<50%) of nitrogen fertilizer in rice paddies. As a first step toward that goal, we have cloned a nitrate transporter gene from rice called OsNRT1. OsNRT1 is a new member of a growing transporter family called PTR, which consists not only of nitrate transporters from higher plants that are homologs of the Arabidopsis CHL1 (AtNRT1) protein, but also peptide transporters from a wide variety of genera including animals, plants, fungi, and bacteria. However, despite the fact that OsNRT1 shares a higher degree of sequence identity with the two peptide transporters from plants (approximately 50%) than with the nitrate transporters (approximately 40%) of the PTR family, no peptide transport activity was observed when OsNRT1 was expressed in either Xenopus oocytes or yeast. Furthermore, contrasting the dual-affinity nitrate transport activity of CHL1, OsNRT1 displayed only low-affinity nitrate transport activity in Xenopus oocytes, with a K(m) value of approximately 9 mM. Northern-blot and in situ hybridization analysis indicated that OsNRT1 is constitutively expressed in the most external layer of the root, epidermis and root hair. These data strongly indicate that OsNRT1 encodes a constitutive component of a low-affinity nitrate uptake system for rice.

Multiple mode regulation of a cysteine proteinase gene expression in rice

In many plants, cysteine proteinases play essential roles in a variety of developmental and physiological processes. In rice (Oryza sativa), REP-1 is a primary cysteine proteinase responsible for the digestion of seed storage proteins to provide nutrients to support the growth of young seedlings. In the present study, the gene encoding REP-1 was isolated, characterized, and designated as OsEP3A. An OsEP3A-specific DNA probe was used to study the effect of various factors on the expression of OsEP3A in germinating seeds and vegetative tissues of rice. The expression of OsEP3A is hormonally regulated in germinating seeds, spatially and temporally regulated in vegetative tissues, and nitrogen-regulated in suspension-cultured cells. The OsEP3A promoter was linked to the coding sequence of the reporter gene, gusA, which encodes beta-glucuronidase (GUS), and the chimeric gene was introduced into the rice genome. The OsEP3A promoter is sufficient to confer nitrogen regulation of GUS expression in suspension-cultured cells. Histochemical studies also indicate that the OsEP3A promoter is sufficient to confer the hormonal regulation of GUS expression in germinating seeds. These studies demonstrate that in rice the REP-1 protease encoded by OsEP3A may play a role in various physiological responses and processes, and that multiple mechanisms regulate the expression of OsEP3A.

Differential scanning calorimetric study of poly(3-hydroxyoctanoate) inclusions in bacterial cells

Medium chain length polyhydroxyalkanoates, MCL-PHAs, produced by bacteria as inclusion bodies or granules were analyzed in situ by differential scanning calorimetry (DSC) without isolation from the cells. The kinetic DSC study of PHA granules, which contained mostly 3-hydroxyoctanoate units (PHO), in Pseudomonas putida BM01 cells showed that the polymer within the granules existed in an amorphous state, but it crystallized after dehydration of the cells under freeze-drying condition (below -50 degrees C) followed by annealing at ambient temperature. In this manner, PHO within the cells readily crystallized to the maximum degree of crystallinity within 24 h at room temperature, which was much faster than for the same polymer isolated by solvent extraction. This observation suggests that the polymer within the cellular granules may be well organized. The DSC endothermic melting peak areas for the room-temperature annealed polymers within the cells were directly proportional to the amount of polymer in the cell, and the results from this type of quantitative analysis were essentially identical to those obtained by gas chromatographic and gravimetric analysis of the polymers. X-Ray diffraction analysis of the polymer in the freeze-dried, whole cells and of the isolated, fully crystallized polymer showed that the two types of PHO samples had similar crystal structures, but the polymer in the granules exhibited better side-chain packing and higher crystallinity.

The 3' untranslated region of a rice alpha-amylase gene mediates sugar-dependent abundance of mRNA

A decrease in transcript stability is one of the important mechanisms that control the sugar repression of alpha-amylase gene expression in rice suspension cells. In this study, we investigated the function of the 3' untranslated region (3'UTR) of a rice alpha-amylase gene, alpha Amy3, in relation to sugar-dependent accumulation of mRNA. By examining the transient expression of chimeric genes in rice protoplasts, we were able to demonstrate that the alpha Amy3 3'UTR mediated the sugar-dependent repression of fused heterologous gene expression. The same kinetics of accumulation of alpha Amy3 mRNA and reporter mRNA carrying the alpha Amy3 3'UTR in response to glucose deprivation were observed, suggesting that the alpha Amy3 3'UTR is sufficient, and probably the major determinant for controlling the abundance of these transcripts. Functional analysis of two subdomains of alpha Amy3 3'UTR by insertion into a sugar-inducible chimeric gene confirmed their roles in sugar repressibility. The regulatory sequences in the alpha Amy3 3'UTR may act as potent determinants of mRNA stability in response to sugar availability. This finding has important implications for studying the regulatory mechanism of sugar repression in eukaryotes.

The 3' untranslated region of a rice alpha-amylase gene functions as a sugar-dependent mRNA stability determinant

In plants, sugar feedback regulation provides a mechanism for control of carbohydrate allocation and utilization among tissues and organs. The sugar repression of alpha-amylase gene expression in rice provides an ideal model for studying the mechanism of sugar feedback regulation. We have shown previously that sugar repression of alpha-amylase gene expression in rice suspension cells involves control of both transcription rate and mRNA stability. The alpha-amylase mRNA is significantly more stable in sucrose-starved cells than in sucrose-provided cells. To elucidate the mechanism of sugar-dependent mRNA turnover, we have examined the effect of alphaAmy3 3' untranslated region (UTR) on mRNA stability by functional analyses in transformed rice suspension cells. We found that the entire alphaAmy3 3' UTR and two of its subdomains can independently mediate sugar-dependent repression of reporter mRNA accumulation. Analysis of reporter mRNA half-lives demonstrated that the entire alphaAmy3 3' UTR and the two subdomains each functioned as a sugar-dependent destabilizing determinant in the turnover of mRNA. Nuclear run-on transcription analysis further confirmed that the alphaAmy3 3' UTR and the two subdomains did not affect the transcription rate of promoter. The identification of sequence elements in the alpha-amylase mRNA that dictate the differential stability has very important implications for the study of sugar-dependent mRNA decay mechanisms.

The 3' untranslated region of a rice alpha-amylase gene functions as a sugar-dependent mRNA stability determinant

In plants, sugar feedback regulation provides a mechanism for control of carbohydrate allocation and utilization among tissues and organs. The sugar repression of alpha-amylase gene expression in rice provides an ideal model for studying the mechanism of sugar feedback regulation. We have shown previously that sugar repression of alpha-amylase gene expression in rice suspension cells involves control of both transcription rate and mRNA stability. The alpha-amylase mRNA is significantly more stable in sucrose-starved cells than in sucrose-provided cells. To elucidate the mechanism of sugar-dependent mRNA turnover, we have examined the effect of alphaAmy3 3' untranslated region (UTR) on mRNA stability by functional analyses in transformed rice suspension cells. We found that the entire alphaAmy3 3' UTR and two of its subdomains can independently mediate sugar-dependent repression of reporter mRNA accumulation. Analysis of reporter mRNA half-lives demonstrated that the entire alphaAmy3 3' UTR and the two subdomains each functioned as a sugar-dependent destabilizing determinant in the turnover of mRNA. Nuclear run-on transcription analysis further confirmed that the alphaAmy3 3' UTR and the two subdomains did not affect the transcription rate of promoter. The identification of sequence elements in the alpha-amylase mRNA that dictate the differential stability has very important implications for the study of sugar-dependent mRNA decay mechanisms.

Sugar response sequence in the promoter of a rice alpha-amylase gene serves as a transcriptional enhancer

Expression of alpha-amylase genes in both rice suspension cells and germinating embryos is repressed by sugars and the mechanism involves transcriptional regulation. The promoter of a rice alpha-amylase gene alphaAmy3 was analyzed by both loss- and gain-of-function studies and the major sugar response sequence (SRS) was located between 186 and 82 base pairs upstream of the transcription start site. The SRS conferred sugar responsiveness to a minimal promoter in an orientation-independent manner. It also converted a sugar-insensitive rice actin gene promoter into a sugar-sensitive promoter in a dose-dependent manner. Linker-scan mutation studies identified three essential motifs: the GC box, the G box, and the TATCCA element, within the SRS. Sequences containing either the GC box plus G box or the TATCCA element each mediated sugar response, however, they acted synergistically to give a high level glucose starvation-induced expression. Nuclear proteins from rice suspension cells binding to the TATCCA element in a sequence-specific and sugar-dependent manner were identified. The TATCCA element is also an important component of the gibberellin response complex of the alpha-amylase genes in germinating cereal grains, suggesting that the regulation of alpha-amylase gene expression by sugar and hormone signals may share common regulatory machinery.

Inhibition of nitric oxide synthase expression by PPM-18, a novel anti-inflammatory agent, in vitro and in vivo

We studied the effect of PPM-18, a chemically synthesized naphthoquinone derivative and also an anti-inflammatory agent, on the lipopolysaccharide (LPS)-activated inducible NO synthase (iNOS) expression in rat alveolar macrophages. Pretreatment of macrophages with PPM-18 (0.1-10 microM) significantly inhibited nitrite production, iNOS protein expression and iNOS mRNA accumulation. PPM-18 did not directly affect the enzymic activities of iNOS and other constitutive NOS forms. The LPS-induced increase in nuclear transcription factor kappaB (NF-kappaB) p65 and p50 in nucleus was suppressed by PPM-18 (10 microM). Moreover electrophoretic mobility-shift assays demonstrated that PPM-18 inhibited DNA binding to NF-kappaB induced by LPS in whole cells but not when added in the nuclear extract, suggesting that PPM-18 did not interfere directly with the binding of NF-kappaB to DNA and that some events had to be processed before NF-kappaB could bind DNA. Examination of NF-kappaB showed that PPM-18 stabilized the NF-kappaB inhibitor, IkappaBalpha, by preventing its degradation from NF-kappaB. Therefore the stabilization of IkappaBalpha might have contributed to the inhibition of NF-kappaB activation. These results also indicate strongly that NF-kappaB is involved in the production of NO on stimulation by LPS. PPM-18 significantly decreased the production of tumour necrosis factor alpha in response to LPS. PPM-18 protects mice against LPS-induced lethal toxicity. These results also indicate that PPM-18 is a potent inhibitor of iNOS expression by blocking the binding of NF-kappaB to promoter and exerts a beneficial effect in the mouse model of sepsis.

Vitamin-mineral supplement use among preschool children in the United States

OBJECTIVE

To estimate the prevalence of recent supplement use in a national sample of preschool children and to examine the relationship of maternal and child characteristics, past maternal supplement use practices, familial, health services, and child health factors associated with supplement use.

METHODS

We used data on 8285 preschool children whose mothers were interviewed for the 1991 Longitudinal Follow-up to the 1988 National Maternal and Infant Health Survey. Data collection was conducted either by telephone or personal interview. The sample is representative of the estimated 3. 8 million US born children in 1988 and alive in 1991. The outcome measures are whether the child was given any vitamin and mineral supplements at least 3 days a week in the 30 days before the interview and the type of supplement received. Statistical techniques included bivariate and weighted multiple logistic regression analysis.

RESULTS

More than half of all US 3-year-olds (54.4%) were given some vitamin and mineral supplement. The most common supplements consumed were multivitamin-mineral with iron (59% of supplement users) and multivitamin-mineral without iron (26.4%). Children who received any supplements tended to have mothers who are non-Hispanic White, older, more educated, married, insured, receiving care from a private health care provider, have greater household income, and took supplements during pregnancy. Child health characteristics associated with supplement use included first birth order and having eating problems or poor appetites.

CONCLUSIONS

More than half of US preschool children used vitamin and mineral supplements. The sociodemographic and health predictors identified for supplement use suggest that groups at risk for nonuse are likely the same groups whose circumstances may predispose a need for supplementation.

Bioactive constituents of Morus australis and Broussonetia papyrifera

The biological activities of the active principles of two plants in the Moraceae have been investigated. A new prenylflavonoid, australone A (1), and a new triterpenoid, 3 beta-[(m-methoxybenzoyl)oxy]urs-12-en-28-ioc acid (2) were isolated from the root bark of Morus australis, and their structures determined by spectroscopic methods. Also isolated from this plant were seven known compounds, morusin (3), kuwanon C (4), betulinic acid, beta-amyrin, quercetin, ursolic acid, and compound A. Morusin (3) showed significant effects on arachidonic acid-, collagen-, and PAF-induced platelet aggregation, while kuwanon C (4) was active in the arachidonic acid- and PAF-induced platelet aggregation assays. In biological work on a second plant, Broussonetia papyrifera, broussoflavonols F (5) and G (6), broussoflavan A (7), and broussoaurone A (8) potently inhibited Fe(2+)-induced lipid oxidation in rat-brain homogenate. Compounds 5-7 also significantly inhibited the proliferation of rat vascular smooth muscle cells.

Smectic ordering in solutions and films of a rod-like polymer owing to monodispersity of chain length

Solutions and melts of stiff ('rod-like') macromolecules often exhibit nematic liquid crystalline phases characterized by orientational, but not positional, molecular order. Smectic phases, in which macromolecular rods are organized into layers roughly perpendicular to the direction of molecular orientation, are rare, owing at least in part to the polydisperse nature (distribution of chain lengths) of polymers prepared by conventional polymerization processes. Bacterial methods for polypeptide synthesis, in which artificial genes encoding the polymer are expressed in bacterial vectors, offer the opportunity to make macromolecules with very well defined chain lengths. Here we show that a monodisperse derivative of poly(gamma-benzyl alpha,L-glutamate) prepared in this way shows smectic ordering in solution and in films. This result suggests that methods for preparing monodisperse polymers might provide access to new smectic phases with layer spacings that are susceptible to precise control on the scale of tens of nanometres.