3D Capsule Networks for Brain Image Segmentation

BACKGROUND AND PURPOSE

Current autosegmentation models such as UNets and nnUNets have limitations, including the inability to segment images that are not represented during training and lack of computational efficiency. 3D capsule networks have the potential to address these limitations.

MATERIALS AND METHODS

We used 3430 brain MRIs, acquired in a multi-institutional study, to train and validate our models. We compared our capsule network with standard alternatives, UNets and nnUNets, on the basis of segmentation efficacy (Dice scores), segmentation performance when the image is not well-represented in the training data, performance when the training data are limited, and computational efficiency including required memory and computational speed.

RESULTS

The capsule network segmented the third ventricle, thalamus, and hippocampus with Dice scores of 95%, 94%, and 92%, respectively, which were within 1% of the Dice scores of UNets and nnUNets. The capsule network significantly outperformed UNets in segmenting images that were not well-represented in the training data, with Dice scores 30% higher. The computational memory required for the capsule network is less than one-tenth of the memory required for UNets or nnUNets. The capsule network is also >25% faster to train compared with UNet and nnUNet.

CONCLUSIONS

We developed and validated a capsule network that is effective in segmenting brain images, can segment images that are not well-represented in the training data, and is computationally efficient compared with alternatives.

Efficacy of laparoscopic gastric bypass vs laparoscopic sleeve gastrectomy in treating obesity combined with type-2 diabetes

OBJECTIVE

This prospective study compared the efficacy and safety of laparoscopic gastric bypass and laparoscopic sleeve gastrectomy in treating overweight and obese patients with BMI>28 kg/m² and type-2 diabetes.

METHODS

Patients were randomized into a gastric bypass group (n = 77) or a gastrectomy group (n = 80). The surgery time, intraoperative blood loss, recovery time, and hospitalization time were collected. BMI, waistline, hipline, C-peptide level, insulin resistance index (HOMA-IR), and their blood and lipid profile were also measured.

RESULTS

Surgery time and blood loss were significantly higher in the gastrectomy group, when compared to the gastric bypass group (P < 0.05). In both groups, the levels of BMI, waist circumference and hip circumference (but not their ratio) gradually and significantly decreased after surgery compared with baseline (P < 0.05), and no significant difference was found between these two groups. The C-peptide level, HOMA-IR, fasting blood glucose, 2-hour postprandial blood glucose and glycosylated haemoglobin gradually and significantly decreased after surgery compared with the values before treatment (P < 0.05). The levels of total cholesterol, triglyceride, LDL, and monocyte chemoattractant protein-1 were also lower after surgery in both groups, while HDL and glucagon-like peptide-1 were significantly higher after surgery compared with the values before treatment (P < 0.05). However, no significant difference was found between these two groups of patients.

CONCLUSION

Both laparoscopic gastric bypass and laparoscopic sleeve gastrectomy improved the BMI and diabetic conditions of overweight/obese diabetics, while laparoscopic sleeve gastrectomy had a shorter surgical time and less blood loss.

USF1 gene polymorphisms may associate with the efficacy and safety of chemotherapy based on paclitaxel and prognosis in the treatment of ovarian cancer

This study was supposed to investigate the correlation between the functional single nucleotide polymorphisms (SNPs) (rs2516839 and rs3737787) in USF1 gene and the efficacy and safety of paclitaxel-based chemotherapy and prognosis in the treatment of ovarian cancer (OC). In total 100 OC patients were selected and divided into the sensitive group and the resistantgroup according to the tumor response to paclitaxel-based chemotherapy after surgery, and the incidence of observed and recorded toxic reaction. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was applied to test the polymorphisms of rs2516839 and rs3737787 in USF1 gene after extraction of DNA. The correlation between USF1 gene polymorphisms and paclitaxel-based chemotherapy resistance was analyzed using Logistic regression analysis. Stratified analysis was used to test the incidence of toxic reaction in OC patients. Cox proportional hazard model was adapted to make a multiple-factor survival analysis. Significant differences exhibited in the genotype and the allele frequencies of rs2516839 between the sensitive and resistant groups, which showed no obvious difference in the genotype and allele frequencies of rs3737787. OC patients carrying the GA+AA genotype had higher incidence of serious toxic reaction than those carrying the GG genotype. Physical status score, tumor type, maximum tumor diameter and rs2516839 were the independent risk factors for the prognosis of OC patients. Taken together, our results suggest that the rs2516839 polymorphism in USF1 gene may associate with the efficacy and safety of paclitaxel-based chemotherapy and prognosis in the treatment of OC.

Synthesis and structure-activity relationship of oleanolic mono- or di-glycosides against Magnaporthe oryzae

Saponins are naturally-occurring units with broad diversity and are usually recognized as phytoanticipins. In order to develop new saponin chemical entities with high activity against Magnaporthe oryzae, we selected oleanolic acid (OA), which has wide natural distribution and rich content in plants. We used the ability of OA to act as an aglycone for glycosylation to obtain information on the structure-activity relationship (SAR) for rational molecular pesticide design. Oleanolic mono- or di-glycosides were synthesized at either the C₃-hydroxy and/or C₂₈-carboxyl position, using trichloroacetimidate or glycosyl bromide donors, respectively. Structures were confirmed by [¹H]-,[¹³C]-NMR. Furthermore, the activity of the synthesized glycosides against M. oryzae was assessed in vitro, based on the mycelium growth rate. The twenty five oleanolic mono- or di-glycosides comprised fourteen saponins with 3-monosaccharide residue 1a-1n, six saponins with 28-monosaccharide residue 2a-2f, and five saponins with 3, 28-monosaccharide residue 3a-3e; all showed different activities against M. oryzae according to their different structures. We concluded that the optimal oleanolic mono- and di-glycoside structure for activity against M. oryzae is a C₃ connection of a hexose such as mannose, galactose, or glucose, in combination with a C₂₈ connection to a small group such as allyl or a C₃ connection to a pentose accompanied by a larger group such as another pentose or heptenyl at C₂₈.

Possible relevance of tumor-related genes mutation to malignant transformation of endometriosis

OBJECTIVE

Despite studies have suggested that endometriosis has malignant potential, the molecular mechanism underlying the malignant transformation of endometriosis is poorly understood so far. Endometriosis-associated ovarian cancer (EAOC) or ovarian cancer arising from endometriosis (OCEM) may provide an ideal model for genetic studies. To investigate the genetic alterations during transformation of ovarian endometriosis into cancer, the authors analysed mutations of tumour-related genes (PTEN and p53) in EAOC cases (n=23, group 1), including 19 cases which were detected co-existence of endometriosis and cancer and four cases which fulfilled the histological criteria in malignant transformation of endometriosis (OCEMs), and in atypical hyperplasia ovarian endometriosis (aEMs) (n = 10, group 2), as well as in solitary ovarian endometriosis (EMs) (n = 20, group 3), simultaneously, to study the correlation of the two genes in the development and progression of the ovarian endometriosis malignancy.

MATERIALS AND METHODS

Each paraffin block was sliced into serial ten-µm-thick sections. Extracted DNA was amplified by nested PCR. Mutations of PTEN and p53 were examined by bidirectional DNA sequencing.

RESULTS

It was acknowledged by experiments that the PTEN and p53 mutation frequency in EAOCs were significantly higher than that in aEMs and EMs. There was significant difference to compare EAOCs with EMs (p < 0.01, p < 0.05), and converse to compare with aEMs (p > 0.05), respectively. No definite involvement between the frequency of PTEN and p53 mutations in EAOCs and age difference, histological type, clinical stage, pathological grade, and whether accompanied by metastasis (p > 0.05); however, a decreasing trend of PTEN mutation with the increased age, decreased clinical stage and pathological grade, and when accompanied by metastasis was detected. Adversely, an increasing trend of p53 mutation was represented. In EAOCs group, the authors detected eight PTEN and four p53 mutation events, respectively. Moreover, one case occurred PTEN and p53 mutation simultaneously. With 23 EAOCs, two cases which fulfilled the histological criteria in malignant transformation of endometriosis, which may be a specific entity distinct from non-endometriosis-associated ovarian cancer, the authors named them the OCEMs, occurred PTEN or p53 mutation, respectively.

CONCLUSION

The present study suggested that the mutation and functional incapacitation of certain tumor-related genes may be involved in malignant transformation of endometriosis. PTEN mutation is the pristine event, but p53 mutation is the late.

Germline mutation analysis in the CYLD gene in Chinese patients with multiple trichoepitheliomas

Trichoepithelioma is a benign neoplasm that primarily shows follicular germinative differentiation. Classic trichoepithelioma typically presents as a skin-colored papule or nodule on the face or upper trunk; lesions have a predilection for the nose. Trichoepithelioma can be sporadic or familial and solitary or multiple. Most previously reported multiple trichoepithelioma cases are familial, and germline CYLD mutations could be detected in some patients. We performed mutational analysis of the germline CYLD gene in 8 Chinese multiple trichoepitheliomas patients, 6 of which were sporadic cases. A heterozygous missense mutation (c.1112C>A) in the 9th exon of the CYLD gene was detected in some mother-daughter patients. However, the germline CYLD mutation could not be detected in the 6 non-familial cases. The results suggest that the pathogenesis of sporadic multiple trichoepitheliomas may differ from that of familial cases. Our findings also further confirmed the genetic heterogeneity of multiple trichoepitheliomas.

Polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) monitored by tree bark in an E-waste recycling area

To investigate the environmental levels and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), tree bark samples (n=22) were collected from Luqiao, an E-waste recycling area, in east China in July 11-13, 2006. The average concentrations of PCDD/Fs, PBDEs, and PCBs determined by isotope dilution-high resolution gas chromatography (HRGC) coupled with high resolution mass spectrometer (HRMS) were 0.1+/-0.0, 1.4+/-0.2, and 6.5+/-0.8 microg g(-1) lipid weight, respectively. PCDD/F-toxic equivalent (TEQ, WHO-1998), PCB-TEQs, and total dioxin-like TEQs were 1.3+/-0.1, 0.5+/-0.0, and 1.8+/-0.2 ng g(-1) lipid weight, respectively. The profiles of these pollutants in the tree bark were also discussed. Tetra-CDFs, deca-BDE and tri-CBs were the main homologues and accounted for 47% of total PCDD/Fs, 79.3% of total PBDEs, and 33.2% of total PCBs, respectively; As for TEQs, 2,3,4,7,8-PeCDF and PCB126 were the main contributors and accounted for 36% of the total PCDD/F-TEQs and 81.2% of the total PCB-TEQs, respectively. High accumulation of PCDD/Fs, PBDEs, and PCBs detected in the tree bark indicated heavy contaminations of these pollutants in Luqiao area.

Essential role of sphingosine-1-phosphate receptor 1-bearing CD8+CD44+CCR7+ T cells in acute skin allograft rejection

A subset of naturally formed sphingosine-1-phosphate receptor 1 (S1P1)-bearing CD8(+)CD44(+)CCR7(+) memory T cells has been identified in transplant recipient BALB/c (H-2(d)) mice. The frequency of this subset of memory T cells is significantly increased in the spleen, lymph nodes and skin grafts in the recipient BALB/c mice during acute skin allograft rejections. The immune-reconstitution with CD8(+)CD44(+)CCR7(+)S1P1(+) memory T cells facilitates acute skin allograft rejection in SCID mice. Being Th1-polarized and cytotoxic, CD8(+)CD44(+)CCR7(+)S1P1(+) memory T cells proliferate and differentiate immediately into effectors upon encountering allo-antigens. A siRNA against S1P1 inhibits CD8(+)CD44(+)CCR7(+)S1P1(+) memory T cell-mediated acute skin allograft rejection in SCID mice by means of knocking-down S1P1-expression. CCL21 mutant (CCL21-DeltaCT) has been used to compete with wild-type CCL21 in the course of binding to CCR7. Combined administration of siRNA S1P1 and CCL21-DeltaCT significantly prolongs the survival of skin allograft in the recipient BALB/c mice by means of inhibiting accumulation of CD8(+)CD44(+)CCR7(+)S1P1(+) memory T cells in the spleen and the skin grafts. Our data provide direct evidence that S1P1 and CCR7 are involved in the proliferation and trafficking of CD8(+)CD44(+)CCR7(+)S1P1(+) memory T cells. S1P1 may serve as a functional marker for CD8(+)CD44(+)CCR7(+) memory T cells. Targeting CD8(+)CD44(+)CCR7(+)S1P1(+) T cells may be a useful strategy to prolong the survival of allograft transplant.

A new strategy to replace the natural vitreous by a novel capsular artificial vitreous body with pressure-control valve

PURPOSE

The current vitreous substitutes such as silicone oil, heavy silicone oil, and polymeric gels that are directly injected into vitreous cavity frequently cause severe intraocular complications. There is a very urgent need to find a more suitable artificial vitreous substitute for pars plana vitrectomy (PPV) surgery.

METHODS

We have devised a novel capsular artificial vitreous using tailor-made silicone rubber elastomer. The novel device was implanted into the vitreous cavity of rabbit after PPV and the eye was examined by ophthalmoscopy, fundus photography, and tonometry during an 8-week treatment period. B-scan ultrasonography, electroretinogram (ERG), and histological studies by light microscopy were also performed at the end of 8 weeks.

RESULTS

The novel artificial vitreous body consists of a thin vitreous-like capsule with a silicone tube-valve system. The capsule can be folded and implanted into vitreous cavity through 1.5 mm incision on sclera. Physiological balanced solution (PBS) was then injected into the capsule and inflated to support retina and control intraocular pressure (IOP) through the tube-valve system subsequently fixed under the conjunctiva. Experiments using rabbits showed that the novel vitreous body could effectively support the retina and apparently induced no significant pathological changes in the eye over 8 weeks.

CONCLUSION

This approach may provide a new research strategy in the vitreous replacement technology. The novel artificial vitreous body device can effectively support retina, control IOP, and has good biocompatibility. It may be a good alternative to injecting artificial vitreous although its tamponade properties and usefulness still have to be proven in complex vitreoretinal diseases.

Congenital nasal pyriform aperture stenosis with semilobar holoprosencephaly

We describe a child who has congenital nasal pyriform aperture stenosis with single maxillary central incisor, holoprosencephaly and central diabetes insipidus without any apparent anterior pituitary dysfunction. Conservative management of the congenital nasal pyriform aperture stenosis is adopted and management of diabetes insipidus is described. A literature review is undertaken.

Recurrent respiratory papillomatosis in a survivor of extreme prematurity

Recurrent respiratory papillomatosis (RRP) is a rare disease in children. Previous reports suggested that prematurity and early age of presentation were poor prognostic factors. We report on a 24-week premature infant who presented with stridor, weak cry, and hoarseness of voice at age 9 months (corrected age), in whom the diagnosis of RRP was not made until age 21 months (corrected age). Laser excision of RRP was subsequently performed, and the child is still surviving at age 2.5 years. RRP should be considered in the differential diagnosis of airway problems in survivors of extreme prematurity; the prognosis is not uniformly poor in premature infants.

Effect of Helicobacter pylori eradication on treatment of gastro-oesophageal reflux disease: a double blind, placebo controlled, randomised trial

BACKGROUND

The role of Helicobacter pylori eradication in the management of gastro-oesophageal reflux disease (GORD) is controversial. We hypothesised that H pylori eradication leads to worsened control of reflux disease.

METHODS

Consecutive patients with weekly reflux symptoms were prospectively recruited for endoscopy and symptom evaluation. Patients were enrolled if they had H pylori infection and required long term acid suppressants. Eligible patients were randomly assigned to omeprazole triple therapy (HpE group) or omeprazole with placebo antibiotics (Hp+ group) for one week. Omeprazole 20 mg daily was given for eight weeks for healing of oesophagitis and symptom relief. This was followed by a maintenance dose of 10 mg daily for up to 12 months. The primary study end point was the probability of treatment failure within 12 months, which was defined as either incomplete resolution of symptoms or oesophagitis at the initial treatment phase, or relapse of symptoms and oesophagitis during the maintenance phase. Predictors of treatment failure were determined by Cox's proportional hazards model.

RESULTS

A total of 236 GORD patients were screened and 113 (47.9%) were positive for H pylori; 104 (92%) patients were included in the intention to treat analysis (53 in the HpE group and 51 in the Hp+ group). Thirty one patients (30%) had erosive oesophagitis at baseline. H pylori was eradicated in 98% of the HpE group and in 3.9% of the Hp+ group. Overall, 15 patients (28.3%) in the HpE group and eight patients (15.7%) in the Hp+ group had treatment failure. The 12 month probability of treatment failure was 43.2% (95% confidence interval (CI) 29.9-56.5%) in the HpE group and 21.1% (95% CI 9.9-32.3%) in the Hp+ group (log rank test, p = 0.043). In the Cox proportional hazards model, after adjustment for the covariates age, sex, erosive oesophagitis, hiatus hernia, degree of gastritis, and severity of symptoms at baseline, H pylori eradication was the only predictor of treatment failure (adjusted hazard ratio 2.47 (95% CI 1.05-5.85)).

CONCLUSION

H pylori eradication leads to more resilient GORD.

Feasibility of implementing a universal neonatal hearing screening programme using distortion product otoacoustic emission detection at a university hospital in Hong Kong

OBJECTIVE

To assess the feasibility of implementing a universal neonatal hearing screening programme using distortion product otoacoustic emission detection at a major teaching hospital in Hong Kong.

DESIGN

Descriptive study and questionnaire. SETTING. Teaching hospital, Hong Kong.

METHODS

A total of 1064 infants, together with their mothers, were successfully recruited for the study. The participation rate was 99.3%. A three-stage hearing screening protocol using distortion product otoacoustic emission detection was adopted. Each of the participating infants was screened on three separate occasions (day 1-4, day 5-14, and day 21-30 after birth), irrespective of the test results. A questionnaire was administered to 364 randomly selected mothers to determine whether as consumers of the hearing screening service, mothers would find screening desirable.

RESULTS

Results of the screening demonstrated an incidence of permanent bilateral hearing loss (>or=40 dB in the better ear) of 0.28%. The results also showed that 3.5% of the screened infants were referred for subsequent diagnostic audiological assessment, including those suspected with unilateral as well as bilateral hearing loss. Data obtained were comparable to other reported results obtained using multi-stage screening protocols. Taking both the false positive rate and the default rate into consideration, the most appropriate time for screening in this hospital setting appeared to be around day 5 to 14 when infants returned to the hospital's day centre as out-patients for routine medical follow-up. Since this day centre service is not generally provided by all maternity hospitals in Hong Kong, an alternative time for screening would be around day 21 to 30 when infants could return as out-patients solely for the hearing test. The results of the questionnaire suggested that most mothers thought a neonatal hearing screening would be desirable (91.35%). The majority (81.70%) indicated a preference for screening either within a few days of birth at the maternity ward prior to discharge from the hospital, or between 5 and 30 days when returning to the hospital as an out-patient.

CONCLUSION

It was concluded that a universal neonatal hearing screening programme could be readily implemented in a maternity hospital setting in Hong Kong.

The role of lamivudine and predictors of mortality in severe flare-up of chronic hepatitis B with jaundice

Patients with chronic hepatitis B (CHB) may develop severe disease exacerbations (flare) with jaundice, and some may progress to fulminant hepatic failure. Whether early administration of lamivudine can prevent liver failure and mortality is uncertain. We investigated the role of lamivudine treatment in severe hepatitis B virus (HBV) exacerbations. Consecutive patients presented with severe flare-up of HBV (new onset of jaundice plus alanine aminotransferase greater than five times upper limit of normal) treated with lamivudine and historical controls who did not receive lamivudine were studied. All patients had no hepatic encephalopathy on admission. Univariate analysis and multivariate logistic regression were performed on various clinical and laboratory factors for the prediction of mortality. Twenty-eight patients treated with lamivudine and 18 controls were identified. Overall, nine patients died and two other received liver transplants for fulminant hepatic failure. Six of 28 (21.4%) lamivudine-treated patients vs five of 18 (27.8%) controls died or received a liver transplant (P = 0.62). On multivariate analysis, platelet < or = 143 x 10E9/L (odds ratio 22.4, 95% CI 1.8-281.6) and bilirubin > 172 micromol/L (odds ratio 18.4, 95% CI 1.5-228.5) were independent predictors of liver-related mortality. The mortality of patients who had thrombocytopenia and high bilirubin, thrombocytopenia, high bilirubin, and no risk factor were 69.2%, 11.1%, 12.5% and 0% respectively. Hence lamivudine confers no survival benefit to conventional treatment in severe exacerbations of CHB. Patients with thrombocytopenia and high bilirubin should be considered for liver transplantation.

Osteoporosis: should there be a screening programme in Hong Kong?

OBJECTIVE

Osteoporosis is rapidly becoming a major health problem in Hong Kong with the ever-increasing population of elderly people. Its importance lies in the predisposition to fragility fractures of patients with the disease. These fractures incur morbidity and mortality to the elderly. Measures are needed to reduce the prevalence of osteoporosis and the incidence of osteoporotic fractures. A screening programme is potentially the way forward in achieving such a goal.

STUDY SELECTION AND DATA EXTRACTION

The need for, and the feasibility of, a screening programme for osteoporosis in Hong Kong were evaluated. A comprehensive examination of the relevant issues was carried out within the framework of the World Health Organization criteria on screening of diseases. Major studies from abroad and Hong Kong were discussed and the strength of evidence was assessed.

DATA SYNTHESIS

Osteoporosis satisfies some of the World Health Organization criteria for screening of diseases: it is a significant health problem, the natural history is fairly well understood, and early detection is possible. Nevertheless, there remain unresolved issues related to the screening tests, the treatments currently available, and the selection criteria for treatment. Several therapeutic options have been tested in trials. However, more work is needed to determine whether, in addition to increasing bone mass, they reduce the incidence of fracture. Moreover, the duration of therapy needed to achieve long-term benefit has yet to be established. More studies are also needed to evaluate the cost-effectiveness of such a programme.

CONCLUSION

There undoubtedly needs to be a means of identifying individuals who have osteoporosis and are susceptible to fragility fractures. However, based on the currently available evidence, large-scale screening is not a valid option. Before instituting such a programme in Hong Kong, more studies are needed to determine the most appropriate and cost-effective way forward.

Eradication of Helicobacter pylori and risk of peptic ulcers in patients starting long-term treatment with non-steroidal anti-inflammatory drugs: a randomised trial

BACKGROUND

Whether Helicobacter pylori increases the risk of ulcers in patients taking non-steroidal anti-inflammatory drugs (NSAIDs) is controversial. We hypothesised that eradication of H pylori infection would reduce the risk of ulcers for patients starting long-term NSAID treatment.

METHODS

Patients were enrolled if they were NSAID naïve, had a positive urea breath test, had dyspepsia or an ulcer history, and required long-term NSAID treatment. They were randomly assigned omeprazole triple therapy (eradication group) or omeprazole with placebo antibiotics (placebo group) for 1 week. All patients were given diclofenac slow release 100 mg daily for 6 months from randomisation. Endoscopy was done at 6 months or if severe dyspepsia or gastrointestinal bleeding occurred. The primary endpoint was the probability of ulcers within 6 months. Analyses were by intention to treat.

FINDINGS

Of 210 arthritis patients screened, 128 (61%) were positive for H pylori. 102 patients were enrolled, and 100 were included in the intention-to-treat analysis. H pylori was eradicated in 90% of the eradication group and 6% of the placebo group. Five of 51 eradication-group patients and 15 of 49 placebo-group patients had ulcers. The 6-month probability of ulcers was 12.1% (95% CI 3.1-21.1) in the eradication group and 34.4% (21.1-47.7) in the placebo group (p=0.0085). The corresponding 6-month probabilities of complicated ulcers were 4.2% (1.3-9.7) and 27.1% (14.7-39.5; p=0.0026).

INTERPRETATION

Screening and treatment for H pylori infection significantly reduces the risk of ulcers for patients starting long-term NSAID treatment.

The murine cysteinyl leukotriene 2 (CysLT2) receptor. cDNA and genomic cloning, alternative splicing, and in vitro characterization

Two classes of cysteinyl leukotriene receptor, CysLT(1) and CysLT(2), have been identified and pharmacologically characterized in human tissues. Although the CysLT(1) receptor mediates the proinflammatory effects of leukotrienes in human asthma, the physiological roles of CysLT(2) receptor are not defined, and a suitable mouse model would be useful in delineating function. We report here the molecular cloning and characterization of the mouse CysLT(2) receptor (mCysLT(2)R) from heart tissue. mCysLT(2)R cDNA encodes a protein of 309 amino acids, truncated at both ends compared with the human ortholog (hCysLT(2)R). The gene resides on the central region of mouse chromosome 14 and is composed of 6 exons with the entire coding region located in the last exon. Two 5'-untranslated region splice variants were identified with the short form lacking exon 3 as the predominant transcript. Although the overall expression of mCysLT(2)R is very low, the highest expression was detected in spleen, thymus, and adrenal gland by ribonuclease protection assay, and discrete sites of expression in heart were observed by in situ hybridization. Intracellular calcium mobilization in response to cysteinyl leukotriene administration was detected in human embryonic kidney 293T cells transfected with recombinant mCysLT(2)R with a rank order of potency leukotriene C(4)(LTC(4) ) = LTD(4)>>LTE(4). [(3)H]LTD(4) binding to membranes expressing mCysLT(2)R could be effectively competed by LTC(4) and LTD(4) and only partially inhibited by LTE(4) and BAYu9773. The identification of mCysLT(2)R will be useful for establishing CysLT(2)R-deficient mice and determining novel leukotriene functions.

[Speech discrimination with bilateral cochlear implants in noisy conditions]

OBJECTIVE

To investigate the speech discrimination abilities of patients with bilateral cochlear implants.

METHODS

The speech discrimination scores of Cantonese lexical tones were compared between two patients with unilateral and bilateral cochlear implants at different signal to noise (S/N) ratios.

RESULTS

At favorable listening conditions with S/N ratios of +15, +10, and the mean binaural speech discrimination scores were 96%, 92% and 88%, but the mean monaural speech discrimination scores from the left and right ear were 86%, 83% and 74% respectively. At unfavorable listening conditions with adverse S/N ratios of 0, -5, -10 and -15, almost no speech discrimination scores could be obtained from monaural hearing but 80%, 72%, 68% and 54% respectively from binaural stimulation.

CONCLUSION

Bilateral cochlear implants improve the discrimination of Cantonese lexical tones better than unilateral cochlear implant at various S/N ratios This study confirms the benefits of binaural hearing even in patients using bilateral cochlear implants.

[Vitrectomy and photocoagulation for treatment of proliferative diabetic retinopathy]

PURPOSE

To evaluate the efficacy of vitreous surgery and photocoagulation for treatment of a series of patients with proliferative diabetic retinopathy(PDR).

METHODS

A consecutive series of PDR treated with vitrectomy and photocoagulation during February 1997 to May 2000 was retrospectively analyzed.

RESULTS

The series included 79 cases (38 male and 41 female) and 104 eyes [oculus dexter(OD), 26; oculus sinister(OS), 28; oculus uterque(OU), 25] with diabetic history for 0.5-37 (8.5 +/- 6.5) years and eye symptoms for 15 days to 1.5 years (1.5 +/- 1.5 years). Retinal photocoagulation was performed in 30 eyes with only once in 26 eyes before vitrectomy. Surgical techniques included standard vitrectomy, neovascular membrane peeling and fragmentation, endo--diathermy and endolaser. Silicone oil was injected in 59 eyes with active bleeding, retinal detachment, or severe ischemia. Cataract extraction was done in 63 eyes, of which 27 eyes with intraocular lens implantation. Visual acuity was light perception(LP), hand movement(HM), count fingers(CF), and > or = 0.02 in 15, 38, 22, and 29 eyes, respectively before operation. Visual improvement achieved in 84 eyes (80.8%) with > or = 0.1 in 41 eyes (39.4%). Visual acuity remained unchanged or decreased in 20 eyes (20.2%). Neovascular glaucoma occurred in two eyes after surgery.

CONCLUSIONS

Although the series of patients with PDR without sufficient retinal photocoagulation before operation, vitrectomy and endolaser improved the visual outcome in the majority of eyes. Silicone oil injected in eyes with severe ischemia, active bleeding or retinal detachment may provide chance for prompt laser coagulation after surgery in order to prevent progression of PDR.

[Observation of phagocytosis and cell junction of rabbit IPE in vitro]

PURPOSE

To study the phagocytosis and cell junctions of iris pigment epithelium(IPE) in vitro.

METHODS

Chicken red blood cells were added to culture medium of IPE, the numbers of IPE phagocyting chick red blood cells were counted; cell junctions were observed with transmission electron microscope.

RESULTS

The phagocytotic rates of IPE and retinal pigment epithelium (RPE) were 5.4% and 8.8% respectively; there were various tight junctions in IPE.

CONCLUSION

IPE possessd phagocytosis and barrier functions in vitro.

Effect of hypericin on confocal imaging of Ca2+ signaling in cultured human retinal pigment epithelium

PURPOSE

To investigate the mechanism of the Ca2+ signaling in cultured human retinal pigment epithelial (RPE) cells with the protein kinase C(PKC) specific inhibitor-hypericin stimulation.

METHODS

Cultured human RPE cells were analyzed using the fluorescence Ca2+ dye fluo-3 AM and laser scanning confocal microscope(LSCM) after stimulation with 100 nM phorbol 12-myristate 13-acetate(PMA) and (or) 5 concentrations of hypericin(1, 2, 3, 4 and 5 microM).

RESULTS

The normal fluorescence in RPE cells was strong and distributed throughout the cells. The nucleus appeared to be more fluorescent than the cytoplasm. After stimulation with PMA alone or 5 concentrations of hypericin, a rapid decrease in flurescence intensity was observed. There was no obvious difference in decreased curve among 5 concentrations. However, after stimulation with a 24 hr preincubation of PMA and 5 concentrations of hypericin, a further decrease was not observed.

CONCLUSION

Fluo-3 AM appears to be a good indicator of the change in Ca2+ occurring in RPE cells and hypericin is a strong inhibitor of Ca2+ influx channel. Hypericin has potential as a therapeutic drug for proliferative vitreoretinopathy(PVR), the inhibitory effect on PVR might be caused by blocking the PKC activity and inhibiting Ca2+ influx pathway.

[Expression of vimentin in lens epithelial cells of age-related cataract]

OBJECTIVE

To observe the expression of vimentin in the lens epithelial cells and superficial cortex of age-related cataract.

METHODS

Twenty-six paraformaldehyde-fixed flat preparations of human lens epithelium attached to the anterior capsule and obtained during extracapsular cataract extraction were studied. Of these, 22 were studied and compared to the 10 samples from normal lenses with antibody to vimentin by avidinbiotinylated peroxidase complex (ABC) method and observed with a light microscope, and 6 (4 cataractous and 2 normal) were used for pre-embedding immunoelectron microscopy. Vimentin in superficial layers (epithelium and superficial cortex) of 4 cataractous lenses were analysed by SDS-polyacrylamide gel electrophoresis (PAGE) and Western blot method.

RESULTS

The average gray level values for expression of vimentin were 143.84 +/- 8.52 and 134.87 +/- 14.27 in cataract and normal group, respectively (t = 2.0948, P < 0.05). Ultrastructure of epithelial cells showed a decrease of intermediate filaments, accumulation of vimentin in bundle and organelle degeneration. Vimentin was identified in the superficial layers of normal and immature cataractous lenses by SDS-PAGE and Western blot. In another two mature cataractous lenses, little vimentin was detected.

CONCLUSION

Decrease of vimentin may be initiated by damage to the epithelial cells leading to degradation of cytoskeleton, and appears to be related with the formation of age-related cataract.

Synthesis of steroidal glycosides bearing the disaccharide moiety of OSW-1 and their antitumor activities

Nine glycosides bearing the disaccharide of OSW-1, namely 2-O-(4-methoxybenzoyl)-beta-D-xylopyranosyl-(1-->3)-2-O-acetyl-alpha-L-arabinopyranosides, were synthesized, and their antitumor activities were tested.

Synthesis of OSW-1 analogues and a dimer and their antitumor activities

Five analogues, including a 16-epi-isomer (6), and a 3-terephthalic acid linked dimer (8) of OSW-1 were synthesized. Their inhibitory activities on P388 and A-549 cells were detected.

Glomangiomyoma of the nasal cavity

Glomus tumor is a rare neoplasm that typically occurs in soft tissue of the extremity, particularly the subungual region of the finger tip. It rarely occurs in the nasal septum. Glomangiomyoma is a rare histologic variant of glomus tumor. The authors describe a case of glomangiomyoma of the nasal septum that presented as nasal obstruction. The histologic, immunohistochemical, and electronmicroscopic findings are described. The otolaryngologist and surgical pathologist should be aware of such an entity, and should not confuse it with the totally unrelated glomus jugulare tumor, or paraganglioma of the middle ear.