[Paying attention to neuropathic changes in high myopia]

The incidence of myopia is high in China. The proportion of high myopia is also high in the myopic population. High myopia is associated with multiple fundus changes, among which the neuropathic damage is usually ignored, and thus there has been limited clinical research on the pathogenesis, standard follow-up and effective treatment of optic neuropathy in high myopia. This article focuses on the types of high myopia-associated neuropathic changes, the quantitive imaging of neuropathic damage, and the need of relevant cohort studies and pathogenesis research, aiming to attract more attention to optic neuropathic changes in high myopia.

[Optic atrophy in a patient with axonal Charcot-Marie-Tooth disease 2A2A due to MFN2 gene mutations]

A 27-year-old male patient had progressive vision loss in both eyes, which was mainly manifested by impaired ganglion cells in the macular area, accompanied by systemic muscle atrophy in limbs. A complete mitochondrial exon gene detection was performed. The final diagnosis was bilateral optic atrophy and axonal Charcot-Marie-Tooth disease 2A2A caused by mutations of the MFN2 gene. There has been no effective treatment. Applications of nutrients to restore the mitochondrial function may alleviate the clinical symptoms.

Outcomes after arthroscopic treatment for scaphoid nonunion using ipsilateral radius bone graft and a headless compression screw: a comparison between the patients with and without avascular necrosis

PURPOSE

To determine whether avascular necrosis can affect clinical outcomes or the union incidence after arthroscopic bone grafting for the treatment of scaphoid nonunion.

METHODS

This retrospective comparative study included thirty-four patients with scaphoid nonunion that underwent arthroscopic bone graft from the ipsilateral radius and internal fixation. The patients were divided into two cohorts (group A, with avascular necrosis, n = 15; group B, without avascular necrosis, n = 19) based on pre-operative magnetic resonance imaging findings. Additionally, the patients were grouped in accordance with the location of nonunion (waist, n = 27; proximal pole, n = 7). The mean follow-up was 20.7 months (range 12.0-40.0 months). Clinical outcomes, including the visual analog scale (VAS) pain score, grip strength, range of motion (ROM), Mayo Wrist Score (MWS), and Disabilities of the Arm, Shoulder, and Hand (DASH) score, were evaluated. Radiographic measurements for carpal bone alignment were assessed as well.

RESULTS

Union rates did not differ between groups (group A, 93.3%; group B, 94.7%: p = 0.863), and the post-operative VAS pain score, ROM, and MWS were similar at follow-up for a minimum of one year. DASH and grip strength were significantly better in group B, but the intergroup differences were minimal (mean DASH 11.9 versus 9.6; mean grip strength 77.5% versus 95.4% of contralateral side). There was no significant intergroup difference in mean time to achieving union (group A, 14.9 weeks; group B, 14.6 weeks; p = 0.900). In post-operative radiographic assessments, no significant intergroup differences were noted in any of the parameters. Subgroup analysis regarding the location of nonunion showed there were no significant intergroup differences in union rates, mean time to achieving union, and clinical outcome measures at the last post-operative follow-up.

CONCLUSIONS

Arthroscopic bone grafting and internal fixation in the treatment of scaphoid nonunion provided good union rates and satisfactory outcomes regardless of vascularity status.

[Update on B cell depletion therapy for demyelinating optic neuritis with disease-specific antibody]

Demyelinating optic neuritis coexisting with seropositive aquaporin-4 antibody or myelin oligodendrocyte glycoprotein antibody is different from the typical optic neuritis in immunopathological, clinical and radiological features, as well as therapeutic response. Due to the high recurrence rate and the potential risk of blindness, immunosuppressive therapy is warranted in most cases. The current review tracks and summarizes both the update and the potential controversies of B cell depletion therapy with a special focus on rituximab for demyelinating optic neuritis to optimize clinical decision-making.

[Myelin oligodendrocyte glycoprotein antibody positive optic neuritis with anti-N-methyl-D-aspartate receptor encephalitis: a case report]

A 6-year-old girl had binocular vision loss with pain for one week. The patient presented with symptoms such as non-communication, language deterioration, dysphonia, and choking when drinking and eating during the course. The serum myelin oligodendrocyte glycoprotein antibody was positive. Both the serum and cerebrospinal fluid anti-N-methyl-D-aspartate receptor antibody were also positive. The diagnoses were myelin oligodendrocyte glycoprotein antibody positive optic neuritis and anti-N-methyl-D-aspartate receptor encephalitis. High-dose intravenous glucocorticoids were given. Recurrence was not observed during the 15-month clinical follow-up.

[IgG4-related ophthalmic disease: three-case report]

The first patient complained visual loss of left eye for 1 week. The second patient complained visual loss of right eye for 2 months with conjunctival edema for more than 10 days. The third patient complained redness and swelling of both eyes for 1 year, poor appetite and fatigue for 4 months. All three patients were male with binocular involvement. Enlargement of lacrimal glands in both eyes with bulbar conjunctival edema were observed in 2 patients and binocular eyelid swelling in 1 patient, all 3 patients were associated with external orbital tissue involvement, which were diagnosed as IgG4-related ophthalmic diseases. After treatment with glucocorticoid, the symptoms of the patients were improved, and the patients were followed up for 58, 54, and 60 months, respectively. Among the 3 patients, 2 had recurrence for once, and 1 had recurrence 3 for times. (Chin J Ophthalmol, 2021, 57: 375-378).

Effect of different types of sugar on gut physiology and microbiota in overfed goose

To explored the difference of goose fatty liver formation induced-by different types of sugar from the intestinal physiology and the gut microflora, an integrated analysis of intestinal physiology and gut microbiota metagenomes was performed using samples collected from the geese including the normal-feeding geese and the overfed geese which were overfed with maize flour or overfeeding dietary supplementation with 10% sugar (glucose, fructose or sucrose, respectively), respectively. The results showed that the foie gras weight of the fructose group and the sucrose group was heavier (P < 0.05) than other groups. Compared with the control group, the ileum weight was significantly higher (P < 0.01), and the cecum weight was significantly lower in the sugar treatment groups (P < 0.001). Compared with the control group, the ratio of villi height to crypt depth in the fructose group was the highest in jejunum (P < 0.05); the trypsin activity of the ileum was higher in the fructose group and the sucrose group (P < 0.05). At the phylum level, Firmicutes, Proteobacteria and Bacteroidetes were the main intestinal flora of geese; and the abundance of Firmicutes in the jejunum was higher in the sugar treatment groups than that of the maize flour group. At the genus level, the abundance of Lactobacillus in the jejunum was higher (P < 0.05) in the sugar treatment groups than that of the maize flour group. In conclusion, forced-feeding diet supplementation with sugar induced stronger digestion and absorption capacity, increased the abundance of Firmicutes and Bacteroidetes and the abundance of Lactobacillus (especially fructose and sucrose) in the gut. So, the fructose and sucrose had higher induction on hepatic steatosis in goose fatty liver formation.

[Safety and short-term efficacy of apatinib combined with oxaliplatin and S-1 in the conversion treatment for gastric cancer with peritoneal metastasis]

Objective: To investigate the safety and short-term efficacy of apatinib combined with oxaliplatin and S-1 in the conversion treatment for gastric cancer with different types of peritoneal metastasis. Methods: A prospective study "one arm exploratory clinical study of conversion therapy of apatinib with S-1 and oxaliplatin in the treatment of advanced gastric cancer" (clinical registration ChiCTR-ONC-17010430) from medical record database was retrospectively analyzed. Patients aged 18-70 years with gastric cancer peritoneal metastasis confirmed by histology and laparoscopic exploration, and had not receive radiotherapy, chemotherapy, targeted therapy or immunotherapy before were enrolled. Before operation, the patients received 6 cycles of S-1 (80-120 mg/d, d1-d14) and oxaliplatin (130 mg/m(2), d1), and 5 cycles of apatinib (500 mg/d, d1-d21) conversion regimen. Three weeks after chemotherapy, whether the operation was performed or not depending on re-evaluation and patient preference. The main outcome were adverse reactions, and the secondary outcome were objective remission rate (ORR), disease control rate (DCR), and overall survival (OS) rate. The follow-up period was up to May 2020. Results: A total of 27 patients with gastric cancer peritoneal metastasis were enrolled in this study. There were 13 males and 14 females, with a median age of 58 (30-68) years old. There were 9 cases of P1a, 5 cases of P1b, and 13 cases of P1c. There were 14 cases with 1-5 scores of PCI (peritoneal cancer index), and 13 cases with 6 scores or above. The incidence of adverse reactions was 100%. The most common adverse reactions were hematological events including leucopenia (70.4%, 19/27) and granulocytopenia (74.1%, 20/27). Non-hematological adverse events included fatigue (51.9%, 14/27) and oral mucositis (37.0%, 10/27). One patient was withdrawn due to grade 4 thrombocytopenia. Among 26 patients with feasible efficacy evaluation, 18 (69.2%) achieved partial remission, 3 (11.5%) achieved stable disease, and 5 (19.2%) disease progression. The objective remission rate was 69.2% (18/26) and the disease control rate was 80.8% (21/26). Fourteen patients underwent surgery, including 6 patients undergoing R0 resection with the R0 resection rate of 42.9% (6/14). The postoperative pathological response rate was 64.3% (9/14). The follow-up time was 12-40 months, and the follow-up rate was 100%. The 1-year OS rate was 65.2% and the survival time was (14.0±1.7) months. The 1-year OS rates of P1a/P1b group and P1c group were 81.8% and 42.0% respectively, whose difference was statistically significant (P=0.041). The 1-year OS rates of PCI 1-5 group and PCI ≥6 group were 67.3% and 38.5% respectively, whose difference was statistically significant (P=0.022). Conclusion: In the conversion treatment of gastric cancer peritoneal metastasis, the safety of apatinib combined with oxaliplatin and S-1 is acceptable, and this regimen shows a good short-term survival efficacy in patients with P1a/P1b and PCI of 1-5.

[The development history and prospect of neuro-ophthalmology in China]

Neuro-ophthalmology is an interdisciplinary subspecialty that occupies an important position in ophthalmology. We review the development history and subspecialty construction of the neuro-ophthalmology in China, showing the achievements, providing reference for the clinical and scientific research of neuro-ophthalmology in the future, commemorating the predecessors and inspiring the contemporary neuro-ophthalmology profession to forge ahead. Congratulations on the 70th anniversary of the publication of the Chinese Journal of Ophthalmology.(Chin J Ophthalmol, 2020, 56:891-894).

[Progress in the treatment of neuromyelitis optica spectrum disorders related optic neuritis]

Neuromyelitis optica spectrum disorders (NMOSD) related optic neuritis (NMOSD-ON) is a common neuro-ophthalmic disease which often results in permanent blindness. NMOSD is characterized by high recurrence rate and poor prognosis. Therefore the two key objectives of the therapeutic approach for patients with NMOSD are treatment of the acute attacks and prevention of the relapses. With the in-depth study of the pathogenesis of NMOSD, new treatments developed for different stages of the disease are emerging. This review gives an update of latest knowledge of NMOSD-ON, emphasizing both current and future therapeutic approaches. (Chin J Ophthalmol, 2020, 56: 539-543).

[The importance of combined application of visual electrophysiology examination and OCT in optic neuropathy]

This article briefly analyzes the advantages and limitations of visual electrophysiology and OCT, and explains the complementarity of visual electrophysiology and OCT and the advantages of combined application in typical optic neuropathy, so as to provide guidance on how to combine the functional and morphological inspections in the clinical diagnosis and treatment of optic neuropathy. (Chin J Ophthalmol, 2019, 55: 161-163).

[Optic nerve subarachnoid space expansion in MR imaging: a etiology study]

Objective: To investigate spectrum of causes in optic nerve subarachnoid space (ONSS) expansion by using Magnetic Resonance Imaging (MRI). Methods: A retrospective study. Twenty-six patients (46 eyes) with ONSS expansion and 20 healthy adults (40 eyes) were recruited in Neuro-ophthalmology Department of Chinese PLA General Hospital from January, 2014 to December, 2015. The diameters were measured on the optic nerve (OND) and optic nerve sheath (ONSD) 2.4 mm behind the globe. ONSS was calculated by the formula of (ONSD-OND)/2. All participants were under went ophthalmologic examinations. The patients' clinical features, MRI and final diagnosis were analyzed. Qualitative data were compared between groups by using chi square test and quantitative data were compared by independent sample t test. Results: There was no statistically significant difference between ONSS group and control group with age, BMI and mean arterial blood pressure (P>0.05). Larger space was found in ONSS group with mean±standard deviation (SD) of (1.9±0.4) mm comparing to the control group with (1.2±0. 2) mm (t=2.879, P<0.01). Bilateral ONSS expansion were found in 20 patients, 15 patients (75%) with cerebral venous sinus thrombosis (CVST), 2 patients (10%) with neurosyphilis, 2 patients (10%) with peri-neuritis and 1 patient (5%) with hydrocephalus. Unilateral ONSS expansion were seen in 6 patients, 4 patients (66.7%) with compressive lesson on anterior visual pathway, 1 patient (16.7%) with fungal infection and 1 patient (16.7%) with peri-neuritis. Conclusions: The CVST patients more frequently presented bilateral ONSS expansion. Unilateral ONSS expansion may indicate compressive lesions located on the anterior visual pathway. (Chin J Ophthalmol, 2016, 52: 911-917).

[Clinical features of neurosyphilis with optic neuritis as an initial finding]

Objective: To study the characteristics of neurosyphilis with optic neuritis as an initial finding. Methods: Retrospective analysis of clinical data and laboratory testing results of 16 cases (27 eyes) with optic neuritis as an initial finding of neurosyphilis from October 2010 to March 2015 in General Hospital of People's Liberation Army was made. Results: Six-teen patients (12 males, 4 females) were collected, the median age of patients was 47 (range 33 to 65) years ,the mean age was (49.63±9.05) years. Treponema pallidum particle agglutination assay (TPPA) analysis was positive in all of the patients and rapid plasma reagin (RPR) test was positive in 14 patients (2 patients did not test). Lumbar puncture was requested and performed for all patients. Cerebrospinal fluid (CSF) TPPA analysis was positive in 16 patients and RPR test was positive in 12 patients. The CSF white blood cell counting increased in 9 (56.3%) patients and 10(62.5%)patients presented with increased CSF protein level. Both eyes were involved in 11 patients (68.8%). Relative afferent papillary defect was positive in 11 patients. Twenty-seven eyes were affected in 16 patients, and among them 7 eyes' pupil diameter were 2.5 mm or less. Incipient visual acuity was less than 0.1 in 22 eyes. The slit lamp examination showed vitreous opacity in 12 eyes and visible cells in 6 eyes among 27 eyes. Fundus examination found that 6 eyes had papillary edema and 15 eyes had pallordisc among 27eyes. Electro-retinogram (ERG) was tested in 24 eyes, and 18 eyes were abnormal. Visual evoked potential (VEP) were performed in 26 eyes (flash VEP in 22 eyes, pattern VEP in 4 eyes), and all were abnormal. Fourteen eyes were tested by 30-2 perimetry, and 6 eyes had diffuse visual field defect, 2 eyes had peripheral visual field defect, 4 eyes had quadrant defect and 2 eyes had center scotoma. Fundus fluorescence angiography was done in 16 eyes and choroidal hyper-fluorescent dots were found in posterior pole in 4 eyes. All patients were treated with antibiotic medicines, among them 10 cases in the General Hospital, and 6 cases in the other hospitals. During 15 months follow-up after discharge, visual acuity of 17 eyes recovered to 0.5 and above. Conclusion: Syphilitic optic neuritis is a condition that manifests with severe visual loss and tends to involve both eyes, Some patients have a smaller pupil diameter. Due to the particular infective routes of the disease, patients often conceal their sexual history. The manifestations of ocular syphilis are complicated and easy to misdiagnose or undiagnose. Clinical manifestations combining with the detailed history taking, serum and cerebrospinal fluid examination can guide to an accurate diagnosis and prevent from permanent vision loss. (Chin J Ophthalmol, 2016, 52: 898-904).

[The immunological effects of phthalanilic acid on mice]

OBJECTIVE

To explore the effects of phthalanilic acid on immune system in mice from the respects of blood, tissues, cell and cytokines. And to find sensitive index of immunological effects and offer experimental data for toxicological safety evaluation.

METHODS

60 balb/c mice were randomly divided into 4 groups. The mice in control group were given soybean oil. The mice in group 2 to 4 were given phthalanilic acid at dose 30 mg/kg, 100 mg/kg and 300 mg/kg by gavage respectively for 28 days. After 24 hours of the last contamination, the histopathology of spleen and thymus, immunologic factors and cell multiplication of lymphocyte were analysed. The data were analysed by SPSS.

RESULTS

After contamination for 28 days, 300 mg/kg phthalanilic acid could cause that the cell multiplication of lymphocyte were inhibited. Spleens were damaged at the dose of 100 mg/kg. The concentration of IFN-γ and IL-4[ (843.31±14.81) pg/ml and (1174.44±7.32) pg/ml] in thymus were increased significantly (P<0.05) at the dose of 30 mg/kg.

CONCLUSION

Different doses of phthalanilic acid may damnify the immune system of mice at different degrees for 28 days continuous contamination. Phthalanilic acid might have immunotoxicity.

Hot Topics in Research: Preventive Neuroradiology in Brain Aging and Cognitive Decline

Preventive neuroradiology is a new concept supported by growing literature. The main rationale of preventive neuroradiology is the application of multimodal brain imaging toward early and subclinical detection of brain disease and subsequent preventive actions through identification of modifiable risk factors. An insightful example of this is in the area of age-related cognitive decline, mild cognitive impairment, and dementia with potentially modifiable risk factors such as obesity, diet, sleep, hypertension, diabetes, depression, supplementation, smoking, and physical activity. In studying this link between lifestyle and cognitive decline, brain imaging markers may be instrumental as quantitative measures or even indicators of early disease. The purpose of this article is to provide an overview of the major studies reflecting how lifestyle factors affect the brain and cognition aging. In this hot topics review, we will specifically focus on obesity and physical activity.

Identification of differentially expressed genes in a pistillody common wheat mutant using an annealing control primer system

HTS-1 is a new kind of pistillody wheat. All or parts of its stamen are transformed into pistils or pistil-like structures, and it has more seed sets per floret than normal wheat under normal cultivation conditions. To investigate the expression divergence in this mutant, an annealing control primer system was used to identify differentially expressed genes (DEGs) in the young spikelets. As a result, three DEGs, including HDB2, HGF2, and HCG4, were detected, with variable expression in HTS-1 and the control. After further confirmation using real-time reverse transcription polymerase chain reaction analysis, these genes were overexpressed in HTS-1 wheat. NGF2 was identified in the double ridge to floret differentiation stages; HDB2 and HCG4 were identified in the stage of pistil and stamen-differentiating. Therefore, we inferred that the homeotic transformation of stamens into pistil-like structures occurred during the early stage of stamen development. Sequence alignment analysis revealed that HDB2 encodes a putative protein of 189 amino acids, with high homology to the DEAD-box ATP-dependent RNA helicase, and HCG4 was identical to the Chinese spring wheat cDNA clone predicted protein according to GenBank. However, NGF2 was not found to have significant similarity to any reported proteins, suggesting it is a new functional gene in wheat. The results suggest that HDB2, HCG4, and HGF2 are minor genes contributing to pistillody trait formation in HTS-1.

Visualization and body distribution of [¹³¹I]-herceptin in nude mice with BT-474 breast carcinoma

The study aimed to investigate the bio-distribution and radio-immuno-imaging features of [(131)I]-herceptin in nude mice with BT-474 breast carcinoma. [(131)I]-Herceptin was administrated by tail intravenous injection to the nude mice with BT-474 breast carcinoma. Radiocounting was performed at 4, 12, 24, 48, and 96 h after administration. The activity ratio in the tumor tissue and non-tumor tissue (T/NT) and the radiocounting percentage per gram tissue to the injected dose (%ID/g) were calculated. The nude mice with BT-474 breast carcinoma were also visualized continuously by single photon emission computed tomography at 2, 4, 8, 12, 24, 48, and 96 h after the injection of [(131)I]-herceptin. Nude mice with MDA-MB-231 used as the control group were subjected to the same analyses. Clear tumor images were obtained after the injection of [(131)I]-herceptin in nude mice with BT-474 breast carcinoma. The images were the clearest at 24 h after the injection and remained clear even at 96 h. The T/NT ratio and %ID/g in the tumor tissues of nude mice with BT-474 were both significantly higher than those of the control group (P < 0.01). [(131)I]-Herceptin displays tumors clearly in the nude mice with BT-474 and accumulates well in the tumor tissues.

Portal vein embolization improves rate of resection of extensive colorectal liver metastases without worsening survival

BACKGROUND

Most patients requiring an extended right hepatectomy (ERH) have an inadequate standardized future liver remnant (sFLR) and need preoperative portal vein embolization (PVE). However, the clinical and oncological impact of PVE in such patients remains unclear.

METHODS

All consecutive patients presenting at the M. D. Anderson Cancer Center with colorectal liver metastases (CLM) requiring ERH at presentation from 1995 to 2012 were studied. Surgical and oncological outcomes were compared between patients with adequate and inadequate sFLRs at presentation.

RESULTS

Of the 265 patients requiring ERH, 126 (47·5 per cent) had an adequate sFLR at presentation, of whom 123 underwent a curative resection. Of the 139 patients (52·5 per cent) who had an inadequate sFLR and underwent PVE, 87 (62·6 per cent) had a curative resection. Thus, the curative resection rate was increased from 46·4 per cent (123 of 265) at baseline to 79·2 per cent (210 of 265) following PVE. Among patients who underwent ERH, major complication and 90-day mortality rates were similar in the no-PVE and PVE groups (22·0 and 4·1 per cent versus 31 and 7 per cent respectively); overall and disease-free survival rates were also similar in these two groups. Of patients with an inadequate sFLR at presentation, those who underwent ERH had a significantly better median overall survival (50·2 months) than patients who had non-curative surgery (21·3 months) or did not undergo surgery (24·7 months) (P = 0·002).

CONCLUSION

PVE enabled curative resection in two-thirds of patients with CLM who had an inadequate sFLR and were unable to tolerate ERH at presentation. Patients who underwent curative resection after PVE had overall and disease-free survival rates equivalent to those of patients who did not need PVE.

Effect of liver X receptor activation on the very low density lipoprotein secretion and messenger ribonucleic acid level of related genes in goose primary hepatocytes

In this study, we investigated the role of liver X receptor (LXR) activation in hepatic assembly and in the secretion of very low density lipoprotein-triglycerides in goose primary hepatocytes. Goose primary hepatocytes were isolated and treated with the LXR agonist T0901317. Total triglyceride accumulation, intracellular and extracellular triglyceride concentrations, extracellular very low density lipoprotein concentration, and gene expression levels of LXRα, microsomal triglyceride transfer protein, acyl coenzyme A:diacylglycerol acyltransferase (DGAT) 1, and DGAT2 were measured in primary hepatocytes. We found a dose-dependent upregulation of total and intracellular TG accumulation when using 0, 0.01, 0.1, 1, and 10 μM T0901317, but the extracellular triglyceride and very low density lipoprotein concentrations were dose dependent only when the T0901317 concentration was below 1 μM; as compared with 1 μM T0901317, 10 μM T0901317 had an inhibiting effect (P < 0.05). The mRNA levels of all the detected genes increased in the presence of T0901317. The change in LXRα and DGAT1 was dose dependent, and the mRNA levels of microsomal triglyceride transfer protein and DGAT2 increased with a T0901317 concentration up to 1 μM, but decreased when treated with 10 μM T0901317 (P < 0.05). In conclusion, the secretion of very low density lipoprotein plays a role in pharmacologically activating the LXR-induced development of hepatocellular steatosis in geese.

Properties of hepatitis C virus minigenome containing mutated 5'UTR region and luciferase transgene

Sequences at the 3'UTR of Hepatitis C virus (HCV) negative-strand (-)RNA play an important role in the initiation of positive-strand (+)RNA synthesis. However, the underlying mechanism in cellular context is still unclear. In this report, we designed several cDNA-based HCV-like minigenomes containing different mutations at the 5'UTR of (+)RNA. These (+)RNAs transcribed from the minigenomes in vitro were transfected into HCV replicon cells for producing (-)RNAs with deletions of different stem loops (SL) at the 3'-end. The results showed that expression of the antisense transgene from minigenome increased, when the minigenome containing deletion of SL-C1+D1+E1 at the 3'-end of (-)RNA was transfected into the HCV replicon cells compared to that of the full minigenome. The expression of the transgene from minigenome decreased using other mutant minigenomes containing deletions SL-A1, SL-A1+B1, and SL-A1+B1+C1 at the 3'-end of (-)RNA. Finally, the transgene from SL-C1+D1+E1 of (-)RNA using CMV promoter-driven minigenome was expressed at higher level than full minigenome in HCV replicon cell lines. These results indicated that the region of (-)RNA interacting with HCV replicase may locate in the SL-C1+D1+E1 region of (-)RNA.

KEYWORDS

Hepatitis C virus; minigenome; RNA dependent RNA polymerase; replication.

Development of a cell-based assay for monitoring hepatitis C virus ns3/4a protease activity

Hepatitis C virus (HCV) NS3/4A (non-structural 3 and 4 B) protease plays a key role in the processing of polyprotein precursor and it becomes an attractive target for antiviral drug discovery. We developed a cell-based assay for monitoring of the NS3/4A protease activity in mammalian cells that is an important step in screening of specific drugs against the protease. The recombinant caspase 3 (rCasp3) was used as the specific substrate for NS3/4A protease. The endogenous cleavage sites in the procaspase 3 molecule were substituted by decapeptides specific for NS3/4A protease. The activation of rCasp3 depended on its specific cleavage by NS3/4A protease and resulted in an apoptosis of stable cells expressing the protease. The difference in cell viability between the cells expressing NS3/4A protease transfected with rCasp3 and the counterparts pretreated with NS3/4A protease inhibitors could be estimated by a spectrophotometry based on 3-(4,5-dimethylthioazol- 2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) staining of cells in microplates. Thus, we developed a simple and cost-effective colorimetric assay for evaluating NS3/4A protease activity enabling the screening of candidate NS3/4A protease inhibitors.

Al7Ag and Al7Au Clusters with Large Highest Occupied Molecular Orbital−Lowest Unoccupied Molecular Orbital Gap

The candidate structures for the ground-state geometry of the Al(7)M (M = Li, Cu, Ag, and Au) clusters are obtained within the spin-polarized density functional theory. Absorption energy, vertical ionization potential, vertical electron affinity, and the energy gap between the highest occupied molecular orbital (HOMO) level and the lowest unoccupied molecular orbital (LUMO) level have been calculated to investigate the effects of doping. Doping with Ag or Au can lead to a large HOMO-LUMO gap, low electron affinity, and increased ionization potential of Al(7) cluster. In the lowest-energy structure of the Al(7)Au cluster, the Al atom binding to the Al(6)Au acts monovalent and the other six Al atoms are trivalent. Thus, the Al(7)Au cluster has 20 valence electrons, and its enhanced stability may be due to the electronic shell closure effect.

A density-functional study of Al-doped Ti clusters: TinAl (n=1–13)

Equilibrium geometries, stabilities, and electronic properties of TinAl (n = 1-13) clusters have been studied by using density-functional theory with local spin density approximation and generalized gradient approximation. The ground-state structures of TinAl clusters have been obtained. The resulting geometries show that the aluminum atom remains on the surface of clusters for n < 9, but is slowly getting trapped beyond n = 9, meanwhile, the Al atom exhibits a valent transition from monovalent to trivalent. The geometric effects and electronic effects clearly demonstrate the Ti4Al cluster to be endowed with special stability. The studies on the bonds indicate the change from ionic to metalliclike.

Effect of different conditioning protocols on adhesion of a GIC to dentin

PURPOSE

This study examined the ultrastructure and microtensile bond strength (microTBS) of a restorative glass-ionomer cement (GIC; Dentsply) to sound dentin that was conditioned with various techniques.

MATERIALS AND METHODS

Dentin surfaces from extracted human third molars were abraded with 180-grit SiC paper. Five groups of three teeth each were prepared: C - no acid pretreatment (control); P - 10% polyacrylic acid (PAA) for 10 s, no rinsing; R - 10% PAA for 20 s, rinsed; K - 25% PAA for 25 s, rinsed; and H -32% phosphoric acid for 15 s, rinsed. TEM was performed on a bonded specimen from each group, using unstained, undemineralized sections. GIC buildups were made on the remaining teeth, and after storage at 100% humidity for 24 h, the teeth were sectioned for microTBS and SEM evaluation.

RESULTS

TEM revealed the presence of a structure known as the intermediate layer in all groups. This layer contains metallic salts contributed by both the GIC and dentin. In group C, this layer was restricted to the smear layer. In groups P and R, intermediate layers could be found above partially demineralized zones within the intertubular dentin. In groups conditioned with more aggressive protocols (K and H), the intermediate layers shifted downward to reside within the superficial portions of completely demineralized collagen. Group C had statistically lower microTBS (p < 0.05), while the other groups were not significantly different from each other. SEM revealed adhesive failures along the dentin surface in group C and mixed failures in the other groups.

CONCLUSION

The lower microTBS observed in the control group reflects the weakness of the smear layer attachment to dentin. The higher microTBS in the other groups probably represent the cohesive strength of GIC under tension, rather than its true adhesive strength to dentin. Acid pretreatment dissolves the smear layer, creates a zone of partially demineralized dentin, and allows the PAA to interact with dentin via the intermediate layer. Overly aggressive conditioning renders the dentinal tubules patent, and leaves deeper demineralized dentin that does not form part of the intermediate layer.

Primary spinal epidural non-Hodgkin's lymphoma in a child

Non-Hodgkin's lymphoma usually involves the central nervous system by metastatic disease. Primary spinal epidural non-Hodgkin's lymphoma (PSENL) is a relatively rare cause of spinal cord compression. It mainly occurs in adults past the 4th or 5th decades. This entity is even rarer in children. The proper treatment modalities are controversial in adults with PSENL. Radiotherapy is the main strategy after surgery; the role of chemotherapy is uncertain. Therapeutic experience in childhood PSENL is extremely limited. We report a 10-year-old boy presenting with backache and bilateral lower leg weakness after minor trauma. Small non-cleaved cell non-Hodgkin's lymphoma of the epidural space was proven after subtotal tumor removal. Other investigations including computed tomography of the chest and abdomen, bone scan, gallium scan, bone marrow aspiration, and cerebrospinal fluid study were all negative for occult disease. The patient received combined therapy with irradiation and chemotherapy after surgery. Esophageal stricture resulting from radiotherapy developed during treatment and colon interposition was performed. He has remained disease free 42 months after the diagnosis with normal functional status.

Dissecting complex epigenetic alterations in breast cancer using CpG island microarrays

It is now clear that aberrant DNA methylation observed in cancer cells is not restricted to a few CpG islands, but affects multiple loci. When this epigenetic event occurs at the 5'-end of the regulatory region of genes, it is frequently associated with transcriptional silencing. To investigate further this widespread event in the tumor genome, we developed a novel microarray containing 7776 short GC-rich tags tethered to glass slide surfaces. This DNA chip was used to study 17 paired tissues of breast tumors and normal controls. Amplicons, representing differential pools of methylated DNA fragments between tumors and normal controls, were cohybridized to the microarray panel. Hypermethylation of multiple CpG island loci was then detected in a two-color fluorescence system. Approximately 1% (on average, 83 loci) of these CpG islands examined were hypermethylated in this patient group. Hierarchical clustering segregated these tumors based on their methylation profiles and identified a group of CpG island loci that corresponds to the hormone-receptor status of breast cancer. This observation was independently confirmed by examining a single locus, the promoter of the human glypican 3 gene, which was predominately hypermethylated in the hormone receptor-negative tumors. Our findings support the notion that hypermethylation of critical CpG island loci influences cancer development and produces distinct epigenetic signatures for particular tumor subtypes.

Clinical investigation of two glass-ionomer restoratives used with the atraumatic restorative treatment approach in China: two-years results

OBJECTIVE

To compare the clinical performance of two glass-ionomer cements, ChemFlex (Dentsply DeTrey) and Fuji IX GP (GC), when used with the atraumatic restorative treatment (ART) approach in China.

METHODS

Eighty-nine school children aged between 6 and 14 years who had bilateral matched pairs of carious posterior teeth were included. A split-mouth design was used in which the two materials were randomly placed on contralateral sides. The performance of the restorations was assessed directly and also indirectly from die-stone replicas at baseline and after 6, 12, and 24 months.

RESULTS

The 24-month cumulative survival rates of ART restorations in the primary teeth were 93 and 90% for the ChemFlex and Fuji IX GP class I restorations, respectively, while 40 and 46% of class II restorations placed with the respective materials were satisfactory. In the permanent dentition, only class I restorations were involved and the cumulative survival rates were 95 and 96% for ChemFlex and Fuji IX GP. For the primary teeth after 24 months, net mean occlusal wear was 87 microm for ChemFlex and 85 microm for Fuji IX GP. The occlusal wear in the permanent teeth was 75 microm for ChemFlex and 79 microm for Fuji IX GP.

CONCLUSION

The clinical performance of both materials over a 24-month period was similar and the survival rates of class I ART restorations in both primary and permanent teeth were high.

Identification and cloning of a key insecticide-metabolizing glutathione S-transferase (MdGST-6A) from a hyper insecticide-resistant strain of the housefly Musca domestica

Strains of the housefly, Musca domestica, highly resistant to organophosphate (OP) and other insecticides are known because they overproduce glutathione S-transferases (GSTs). Previous work has shown that overproduction in these strains involved numerous isozymes with glutathione conjugating activities (Pesticide Biochem. Physiol., 25 (1986) 169; Mol. General Genetics, 227 (1991) 355; J. Biol. Chem., 267 (1992) 1840; Mol. General Genetics, 245 (1994) 236; J. Mol. Evol., 43 (1996) 236). The current work describes the purification and identification of a M. domestica GST isozyme (pI 7.1) broadly specific for substrates from a housefly strain, Cornell-HR, that is highly resistant against OP-insecticides, and the isolation of two new MdGST genes using the antibody made against it. This isozyme, which was identified from amongst more than 20 isoelectric forms of GSTs of the same subunit size, was highly active for conjugating GSH to the model substrate 3,4-dichloronitrobenzne (DCNB). When expressed in Escherichia coli, one of the cloned GSTs, MdGST-6A, produces an enzyme that conjugates glutathione to the insecticides methyl parathion and lindane. On indication that it was the most active isozyme toward several xenobiotics among several MdGSTs tested, we advance the notion that MdGST-6A probably plays an important role in M. domestica Cornell-HR's resistance towards OP-insecticides. MdGST-6A and a second closely related one found in this work, MdGST-6B, are members of the traditional insect class I family (theta-class) and share the greatest homologies with a cluster of Drosophila GSTs on locus 55. In addition to having the unusually broad substrate specificity, the sequence of the new group of enzymes reveals that it has a highly diverged hydrophobic motif in its active site as compared to other class I GSTs from insects.

Steps on As-terminated Ge(001) revisited: theory versus experiment

We examine the double-layer B-type steps on As-terminated vicinal Ge(001) surfaces. The currently accepted structure is a chemically inert bulklike structure without any gap state, and with all the chemical bonds of the Ge and As atoms being satisfied. However, we show that the need for optimizing the p(3) pyramidal angles of the threefold coordinated As atoms drives unusual atomic rearrangement. This leads to a more stable reconstruction involving odd-membered (5-7-5) rings at the step edge. Comparison between theoretical and experimental scanning tunneling microscopy images yields excellent agreement.

A new mode of percutaneous upper thoracic phenol sympathicolysis: report of 50 cases

OBJECTIVE

Our previous study demonstrated that a high concentration of phenol (75-90%) with minimal volume (0.02 ml) can elicit serious degeneration of ganglion cells of the stellate ganglia in cats. Another previous study in our clinical patients demonstrated that approximately 84 to 90% of the upper thoracic (T2-T3) sympathetic trunks can be found under an endoscope on the ventral side of the T2-T3 rib heads. In this report, we present a new mode of dorsal percutaneous thoracic phenol sympathicolysis (PTPS) for the treatment of palmar hyperhidrosis or axillary bromidrosis.

METHODS

Fifty patients with palmar hyperhidrosis or axillary bromidrosis were injected with 75% phenol into a total of 98 sides of the T2-T3 or T3-T4 sympathetic trunks and ganglia. The injected volume was 0.6 to 1.2 ml (average, 0.8 ml) for each side. The technique of dorsal percutaneous injection was performed under local anesthesia or local with intravenous general anesthesia and under the guidance of a C-arm fluoroscope.

RESULTS

Forty patients (80%) showed satisfactory results, including cessation of sweating. The success rates of PTPS were 83.7% (41 of 49 patients) on the left side and 91.8% (45 of 49 patients) on the right side. The skin temperature of the thumb increased by 5.3 to 5.4 degrees C approximately 1 hour after the phenol injection in patients with satisfactory results, whereas it increased by only 1.3 to 2.7 degrees C in patients who had unsatisfactory results.

CONCLUSION

PTPS may be a good alternative to endoscopic sympathectomy to treat palmar hyperhidrosis and axillary bromidrosis. The skin temperature of the thumb is still a useful index to evaluate preliminarily whether PTPS has been successful.

Indirect posterior restorations using a new chairside microhybrid resin composite system

A plethora of choices is available as potential tooth-colored restoratives for the posterior dentition. Advances in adhesive technology and esthetic chairside microhybrid composite resins have permitted clinicians to perform inlay/onlay restorations. The use of adhesive indirect procedures offers advantages such as better control of polymerization shrinkage and anatomical form, when compared to conventional, direct restorative techniques. This article describes the use of a new chairside microhybrid composite system as an indirect restorative material, using semidirect and indirect techniques that can be accomplished within the realm of a dental operatory.

Management of median diastema

In mixed and early permanent dentitions, median diastema can be a major esthetic concern for patients and/or their parents. The space can be transient or created by developmental, pathological, or iatrogenic factors. Different treatment techniques have been proposed to manage the situation. This paper reviews the common causes of median diastema and presents four cases to illustrate a range of restorative and orthodontic options.

Biodegradation of phenanthrene in soil

We investigated the potential of an aerobic polycyclic aromatic hydrocarbon (PAH)-adapted consortium to degrade phenanthrene in soil. Optimal degradation conditions were determined as pH7.0 and 30 degrees C with a water content of 100% wt soil/wt water (w/w). At a concentration of 5 microg/g, phenanthrene degradation (k1) was measured at 0.0269 l/hr with a half-life (t(1/2)) of 25.8 hrs. Our results show that the higher the phenanthrene concentration, the slower the degradation rates. Phenanthrene degradation was enhanced by treatment with yeast extract, glucose, or pyruvate, but was not significantly improved by the addition of acetate. Degradation was delayed by the addition of either compost or potassium nitrate and enhanced by the addition of nonionic surfactants (Brij30, Brij35, Triton X100 or Triton N101) at critical micelle concentration (CMC). Phenanthrene degradation was delayed at levels above CMC.

Nitrogen solubility and induced defect complexes in epitaxial GaAs:N

Thermodynamic calculation suggests that the formation of bulk GaN pins N chemical potential mu(N)< or =mu(max)(N), resulting in low equilibrium N solubility [N] in bulk GaAs:N. In epitaxial growth, however, a fully relaxed GaN phase cannot form prior to the spontaneous formation of a N-rich layer on the surface. First-principles total-energy calculations show that in the epitaxial regime one can increase mu(max)(N) considerably from equilibrium mu(max)(N) without triggering the spontaneous formation of such a N-rich layer. This enhances [N] by 8 orders of magnitude to about 4% at T = 650 degrees C in agreement with experiments. The dominant defects at high N concentration are qualitatively different from those at low [N].

Biodegradation of polycyclic aromatic hydrocarbons by a mixed culture

We investigated the potential biodegradation of polycyclic aromatic hydrocarbons (PAHs) by an aerobic mixed culture utilizing phenanthrene as its carbon source. Following a 3-5 h post-treatment lag phase, complete degradation of 5 mg/l phenanthrene occurred within 28 h (optimal conditions determined as 30 degrees C and pH 7.0). Phenanthrene degradation was enhanced by the individual addition of yeast extract, acetate, glucose or pyruvate. Results show that the higher the phenanthrene concentration, the slower the degradation rate. While the mixed culture was also capable of efficiently degrading pyrene and acenaphthene, it failed to degrade anthracene and fluorene. In samples containing a mixture of the five PAHs, treatment with the aerobic culture increased degradation rates for fluorene and anthracene and decreased degradation rates for acenaphthene, phenanthrene and pyrene. Finally, it was observed that when nonionic surfactants were present at levels above critical micelle concentrations (CMCs), phenanthrene degradation was completely inhibited by the addition of Brij 30 and Brij 35, and delayed by the addition of Triton X100 and Triton N101.

Dynamic joint and muscle forces during knee isokinetic exercise

Isokinetic exercise has been commonly used in knee rehabilitation, conditioning and research in the past two decades. Although many investigators have used various experimental and theoretical approaches to study the muscle and joint force involved in isokinetic knee extension and flexion exercises, only a few of these studies have actually distinguished between the tibiofemoral joint forces and muscle forces. Therefore, the objective of this study was to specify, via an eletromyography(EMG)-driven muscle force model of the knee, the magnitude of the tibiofemoral joint and muscle forces acting during isokinetic knee extension and flexion exercises. Fifteen subjects ranging from 21 to 36 years of age volunteered to participate in this study. A Kin Com exercise machine (Chattecx Corporation, Chattanooga, TN, U.S.A.) was used as the loading device. An EMG-driven muscle force model was used to predict muscle forces, and a biomechanical model was used to analyze two knee joint constraint forces; compression and shear force. The methods used in this study were shown to be valid and reliable (r > 0.84 andp < 0.05). The effects on the tibiofemoral joint force during knee isokinetic exercises were compared with several functional activities that were investigated by earlier researchers. The muscle forces generated during knee isokinetic exercise were also obtained. Based on the findings obtained in this study, several therapeutic justifications for knee rehabilitation are proposed.

Clinical evaluation of polyacid-modified resin composite posterior restorations: one-year results

OBJECTIVE

The aim of this investigation was to evaluate the clinical performance of a new compomer restorative system, Dyract AP, placed in combination with Non-Rinse Conditioner and Prime & Bond NT in permanent posterior teeth.

METHOD AND MATERIALS

Fifty Class II and 41 Class I restorations were placed in 39 patients by 1 dentist. The restorations were evaluated directly, with modified US Public Health Service criteria, and indirectly, with color slides and polyvinyl siloxane impressions, at baseline and 6 months and 1 year after placement. Preoperative and 1-year postoperative bitewing radiographs were also taken.

RESULTS

All 82 restorations available for 1-year evaluation were in situ. No postoperative sensitivity or pulpal problems were reported. Four Class II restorations (4.9%) failed because of partial fracture or recurrent caries. The percentages of Alfa score for each criterion were color match, 95.1%; marginal discoloration, 57.3%; marginal integrity, 35.4%; anatomic form, 98.8%; and surface texture, 91.5%. The average wear rate of Dyract AP was low (18.5 +/- 11.7 microns at 6 months and 35.7 +/- 13.6 microns at 12 months).

CONCLUSION

The excellent handling characteristics, the good clinical performance, and the improved wear resistance suggest that this compomer will provide reliable direct tooth-colored restorations in stress-bearing areas.

Marginal adaptation of a new compomer under different conditioning methods

OBJECTIVES

This in vitro study evaluated the marginal adaptation of compomer restorations placed using three different conditioning protocols.

MATERIALS AND METHODS

Thirty extracted caries-free molars with 3mm diameter cylindrical cavity preparations were divided randomly into three groups based upon the conditioning treatment used: (I) 36% phosphoric acid; (II) non-rinse conditioner (NRC, Dentsply DeTrey); and (III) no conditioning. Cavities were restored with Dyract AP using Prime&Bond NT (Dentsply DeTrey) as an adhesive. Silicone impressions of the briefly etched enamel surfaces were taken after finishing the restorations. Each sample was then longitudinally sectioned and impressions were taken. Epoxy resin replicas were prepared for SEM analysis. Qualitative and quantitative assessment were performed separately for the enamel- and dentine-restorative interface.

RESULTS

Enamel fractures and open margins along the enamel-restorative margin were observed in some specimens in each group. No statistically significant difference was found in the percentage of gaps/cohesive failures between specimens prepared using different conditioning methods. For the dentine-restorative interface, uniform hybrid layers and long resin tags were often observed in Groups I and II. The hybrid layer in Group III was irregular and discontinuous along the interface. A significant difference (p<0.01) in the proportion of marginal gap was found between Group I (2%) and Group III (30%).

CONCLUSIONS

Pre-treating the cavity with 36% phosphoric acid significantly improved the adaptation of the compomer and adhesive to dentine compared with no etching. The marginal quality at the enamel-compomer interface was not affected by the conditioning method used.

Clinical considerations for reattachment of tooth fragments

Trauma to anterior teeth is relatively common among children and teenagers; it has been estimated that approximately one quarter of the population under the age of 18 years sustain traumatic injury in the form of anterior crown fracture. Reattachment of a fractured fragment to the remaining tooth can provide esthetically pleasing results provided that the fragment is available. In this report, a systematic clinical approach through evaluation of periodontal, endodontic, coronal, and occlusal aspects is presented to help dentists analyze the factors affecting selection of techniques and materials. In addition, use of adhesive materials for tooth fragment reattachment is illustrated. Modifications of the reattachment process, including placement of veneer and radicular post, are also discussed.

The effect of different commercial dentifrices on enamel lesion progression: an in vitro pH-cycling study

AIMS/OBJECTIVES

To evaluate and compare the de/remineralization effects of dentifrices manufactured locally in some developing countries.

DESIGN

Utilisation of the in vitro single-section and the pH-cycling model.

SETTING

Laboratory. TEST MATERIALS: Dentifrices: Maxam DFP, Maxam Tartar Control, First, Tianqi Medicated from China; Vicco Vajradenti from India; Colgate MFP2, Crest Tartar Control from USA; and one non-fluoride dentifrice as control.

METHODS

Sound molars were painted, leaving a 1 mm wide 'window' on the buccal and/or lingual surface and placed in a demineralisation solution for 96 h to produce artificial caries lesion approximately 80-100 mm deep. The teeth were then longitudinally sectioned (approximately 100 mm thick), and randomly divided into 8 groups (22 sections/group). The pH cycling model was utilised for 10 days.

OUTCOME MEASURES

Polarised light microscopy and microradiography were used to evaluate the lesion progression before and after treatment.

RESULTS

The control group showed an increase in lesion depth of 70 per cent and was statistically different from some test groups which ranged from -2 per cent to 68 per cent (P < 0.01, t-test). Statistically significant differences were also observed among some of the fluoride containing groups.

CONCLUSIONS

This study suggests that, when compared to 'multinational dentifrices', Chinese and Indian dentifrices manufactured locally failed to show 'healing' efficacy even though they claimed to contain varying levels of fluoride.

Clinical investigation of a high-strength glass ionomer restorative used with the ART technique in Wuhan, China: one-year results

OBJECTIVE

To evaluate the safety and effectiveness of a new glass ionomer restorative, ChemFlex, and to compare its clinical performance and wear to another popular material, Fuji IX GP, when used with the atraumatic restorative treatment (ART) approach in posterior teeth in school children.

METHODS

Ninety-two subjects aged between 6 and 14 years who had bilateral matched pairs of carious posterior teeth were selected. A split-mouth experimental design was used in which the two restorative materials were randomly placed on contralateral sides. The restorations were assessed directly and also indirectly from color transparencies and die replicas.

RESULTS

After one year, the success rates of ART restorations in the primary teeth were 96.6% for ChemFlex restorations and 89.7% for Fuji IX GP restorations placed in the Class I cavity preparations, whereas only 46.2% (ChemFlex) and 61.5% (Fuji IX GP) of Class II restorations were assessed as clinically satisfactory. In the permanent dentition, the success rates were 94.6% and 98.2% for ChemFlex and Fuji IX GP, respectively; however, there was no statistically significant difference between the two restoratives for either the permanent or primary teeth. The mean occlusal wear after one year in the permanent teeth was 53.2 microns for ChemFlex and 56.3 microns for Fuji IX GP. Again, there were no statistically significant differences in wear between the two materials (P > 0.05).

CONCLUSION

The clinical performance of both ChemFlex and Fuji IX GP over a 12-month period was highly satisfactory and completely adequate for the ART technique, particularly in Class I cavities.

Morphology of initial lesions of enamel treated with different commercial dentifrices using a pH cycling model: scanning electron microscopy observations

The aim of this study was to evaluate and compare the 'calcium fluoride-like reaction products' formed, both on the surface and in the subsurface caries-like lesions of enamel, from different commercial dentifrices manufactured locally from developed and developing countries. The experiment was conducted by using the in vitro single-section technique under the pH-cycling system used for 10 days. The tested dentifrices include; Maxam DFP Maxam Tartar Controls, First, Tianqui Medicated (China); Vicco Vajradenti (India); Colgate MFP2. Crest Tartar Control (USA); and a non-fluoride dentifrice, Jie Yin (China) used as control. The surface and subsurface of the lesions, before and after treatment, were examined using scanning electron microscopy. Varying degrees of fine globular patterns of calcium fluoride-like material were observed on the enamel surfaces of five out of eight groups and in the subsurface of four groups. Two treatment groups showed a 'similar appearance' compared with the control and untreated groups. This study suggests and supports that, when compared with 'multinational dentifrices', some Chinese and Indian dentifrices manufactured locally failed to induce the typical morphological appearance of globules as seen with fluoride dentifrices.

The influence of rehabilitation therapy on the prognosis for stroke patients--a preliminary study

The purpose of this prospective study was to investigate the influence of rehabilitation therapy on the prognosis for stroke patients. Sociodemographic and clinical factors were collected in a sample of 147 stroke patients (81 men and 66 women) admitted to the inpatient rehabilitation department at our university hospital over 10 days between January 1, 1997 and December 31, 1997. Functional Independence Measure (FIM) scores at discharge and gains during rehabilitation period were used as the prognosis index. Statistical techniques with univariate and multiple regression analyses indicated that significant predictors of discharge FIM scores include age, previous attacks twice or over, medical comorbidities, sensory and orientation impairments, and dementia. In addition, previous stroke attacks twice or over and sensory impairment were significant predictors of FIM gains during rehabilitation period. We concluded that: 1) age is a critical factor to determine the rehabilitation outcome, but may not be an important factor to predict the ability for the improvement through rehabilitation therapy; 2) the delay of rehabilitation therapy may not affect the potential for further improvement; 3) patients with low initial functional level may have poor final outcome, they may still have good rehabilitation potential to improve the functional level; 4) complications of stroke may affect the rehabilitation outcome and should be prevented; and 5) patients with impaired mental status should not routinely be excluded from rehabilitation programs.

Resin-ionomer restorative materials for children: a review

Hybrid restorative materials comprising resins and components of conventional glass ionomers have been widely introduced and accepted by the dental profession in recent years. These include the resin-modified glass ionomer cements and the polyacidmodified resin composites or compomers. They are developed in an attempt to overcome the problems of traditional restoratives, such as moisture sensitivity and reduced early strength, while at the same time maintaining their clinical advantages of command setting, adhesion to tooth structures, adequate strength to occlusal load, fluoride release and aesthetics. This paper reviews the development, composition and properties of these new materials. Their clinical performance appears to be promising and they should be considered as good alternatives to amalgam and other conventional restorative materials in the future.

Micromorphological spectrum of acid-conditioned dentin following the application of a water-based adhesive

OBJECTIVES

The goal of this study was to illustrate the micromorphological spectrum along the resin-dentin interface when a water-based, dentin adhesive (Scotchbond Multi-purpose) was applied to acid-conditioned dentin under different dry and wet bonding conditions.

METHODS

Twenty-eight 1 mm dentin discs were each conditioned with 10% maleic acid for 15 s. Twenty-four of these discs were randomly divided into four groups, based upon the status of the remaining surface moisture: Group I (30 s dry); Group II (3 s dry); Group III (visibly moist) and Group IV (overwet). They were bonded using Scotchbond Multi-purpose. The remaining four discs were bonded using an experimental water-based primer containing 35 vol.% HEMA (Group V). Laminated dentin disc pairs were prepared for transmission electron microscopic examination.

RESULTS

In all groups, diffusion of the polyalkenoic acid copolymer component of the primer into acid-conditioned dentin was localized to the surface region of the hybrid layer. The remaining part of the hybrid layer (the subsurface region) appeared variable. In Group I (30 s dry), collagen fibrils were collapsed. In Group II (3 s dry) and Group III (visibly moist), stained collagen fibrils were surrounded by wide electron-lucent interfibrillar spaces. In Group IV (overwet), a marked diffusion gradient was observed representing dilution of part of the primer components. In addition, an electron-dense primer phase, containing electron-lucent globular domains was invariably observed, irrespective of the hydration status of the demineralized collagen matrix. This electron dense phase was absent when HEMA alone was used as the primer (Group V).

SIGNIFICANCE

With the use of a water-based adhesive, one could briefly air-dry the acid-conditioned dentin and allow the water in the primer to rehydrate the collapsed collagen matrix, without the risk of incomplete hybridization or tubular seal along the resin-dentin interface. However, care should be exercised to minimize dilution of the water-soluble primer component.