A formal selection and pruning algorithm for feedforward artificial neural network optimization

A formal selection and pruning technique based on the concept of local relative sensitivity index is proposed for feedforward artificial neural networks. The mechanism of backpropagation training algorithm is revisited and the theoretical foundation of the improved selection and pruning technique is presented. This technique is based on parallel pruning of weights which are relatively redundant in a subgroup of a feedforward neural network. Comparative studies with a similar technique proposed in the literature show that the improved technique provides better pruning results in terms of reduction of model residues, improvement of generalization capability and reduction of network complexity. The effectiveness of the improved technique is demonstrated in developing neural network (NN) models of a number of nonlinear systems including three bit parity problem, Van der Pol equation, a chemical processes and two nonlinear discrete-time systems using the backpropagation training algorithm with adaptive learning rate.

Prognostic factors and adjuvant therapy in uterine carcinosarcoma

PURPOSE OF INVESTIGATION

The objective of this retrospective study was to investigate prognostic variables and impact of adjuvant therapy in uterine carcinosarcoma.

METHODS

The clinical information and pathological confirmation were reviewed for cases with uterine carcinosarcoma from 1984 to 2005. A total of 45 patients were eligible for analysis.

RESULTS

The median follow-up for survivors was 84 months. Five-year overall survival and progression-free survival (PFS) rates were 36.5% and 33.8%, respectively for Stage I-IV. Distant site metastasis with/without pelvic failure occurred in 83.3% of those with recurrence/progression. By multivariate analysis, older age (p = 0.001) and more than half of myometrial invasion (p = 0.002) were significant predictors of death, while only myometrial invasion (p = 0.022) was significantly associated with PFS. Stratified analyses demonstrated a monotonic trend of chemotherapy or chemoradiation to decrease death.

CONCLUSIONS

Our results suggested that age and depth of myometrial invasion were significant prognostic factors, and chemotherapy or chemoradiation seemed to be beneficial for uterine carcinosarcoma.

Spatial correlation coefficient images for ultrasonic detection

In ultrasonics, image formation and detection are generally based on signal amplitude. In this paper, we introduce correlation coefficient images as a signal-amplitude independent approach for image formation. The correlation coefficients are calculated between A-scans digitized at adjacent measurement positions. In these images, defects are revealed as regions of high or low correlation relative to the background correlations associated with noise. Correlation coefficient and C-scan images are shown to demonstrate flat-bottom-hole detection in a stainless steel annular ring and crack detection in an aluminum aircraft structure.

Supraclavicular lymph node metastases in cervical cancer

PURPOSE OF INVESTIGATION

To evaluate the outcome and prognostic factors of patients with supraclavicular lymph node (SCLN) involvement at primary diagnosis.

METHODS

We reviewed the medical records of cervical cancer patients primarily treated at Chang Gung Memorial Hospital between 1987 and 2005. Thirty-three patients with histologically confirmed SCLN metastasis at primary diagnosis were eligible for analysis. Clinical and pathological features were analyzed for association with outcome.

RESULTS

The 3- and 5-year survival rates of patients with SCLN metastasis were 16.5% and 16.5%, respectively. Multivariate analysis showed the serum level of squamous cell carcinoma antigen (SCC-Ag) < 15 ng/ml at initial diagnosis (p = 0.021) and staging/restaging including [18F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) (p = 0.006) to be associated with a better prognosis.

CONCLUSION

Primary SCLN metastasis in cervical cancer is not incurable. The benefit from PET findings might help in selecting appropriate patients for curative primary and/or salvage treatment.

Peritoneal metastasis in primary cervical cancer: a case report

PURPOSE OF INVESTIGATION

Peritoneal metastasis presenting at initial diagnosis of squamous carcinoma of the uterine cervix is extremely rare. However, one such case was treated successfully with curative treatment.

CASE

A 43-year-old woman presented with FIGO Stage IVA cervical carcinoma and underwent concurrent chemoradiation (CCRT) with weekly cisplatin. During CCRT, she suffered from acute lower abdominal pain, high fever, and leukocytosis. Computed tomography (CT) favored a tubo-ovarian abscess, while [18F] fluorodeoxyglucose positron emission tomography (FDG-PET) showed a lesion midway between the umbilicus and symphysis pubis. An exploration by laparoscopy, an omental metastasis adhering to the bladder dome was excised. This patient finished CCRT encompassing the disease extent including the trochar sites and no evidence of disease was noted 50 months after initial diagnosis.

CONCLUSION

Though peritoneal metastasis above the pelvis seems ominous, curative treatment may still be viable in selected patients, even in surgical Stage IVB.

Role of [18F]fluoro-2-deoxy-D-glucose positron emission tomography in re-recurrent cervical cancer

Cervical cancer patients with histologically documented re-recurrence after curative salvage therapy or unexplained tumor marker elevation (negative computed tomography and/or magnetic resonance imaging [CT-MRI]) proven to be a re-recurrence when a further attempt for cure (or control of cancer) appeared feasible were enrolled. Lesion status was determined from pathology or clinical follow-up for at least 12 months. Management decisions were recorded with CT-MRI alone and incorporating [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), respectively. The benefits calculated were based on clinical impact because of the FDG-PET findings. Cox proportional hazards model was used to select independent prognostic covariates. Of the 26 patients who were eligible for analysis, 12 (46.2%) patients had positive impacts due to PET. Squamous cell carcinoma (SCC,P= 0.029), re-recurrence at distant metastasis only (P= 0.012), and level of SCC antigen ≤4 ng/mL (P= 0.005) were significantly associated with better survival. A scoring system using these covariates defined three distinct prognostic groups (P= 0.0001). Patients with score 0 had a 36-month cumulative survival rate of 80%. Using this prognostic scoring system, FDG-PET may facilitate selecting appropriate management for the individual patient with re-recurrent cervical cancer.

An ovary in luteal phase mimicking common iliac lymph node metastasis from a primary cutaneous peripheral primitive neuroectodermal tumour as revealed by 18-fluoro-2-deoxyglucose positron emission tomography

A 30-year-old female underwent surgical removal of a primary cutaneous peripheral primitive neuroectodermal tumour (PNET) of the left thigh. A subsequent 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) scan showed abnormal accumulation of FDG in the left upper pelvic region, consistent with metastasis to a left common iliac node. A series of follow-up imaging studies revealed that a cyst of the corpus luteum of ovary was responsible for the abnormal FDG accumulation.

Chemical and microbiological qualities of The East River (Dongjiang) water, with particular reference to drinking water supply in Hong Kong

Currently, about 80% of drinking water in Hong Kong is abstracted from The East River (Dongjiang) that is located in the mainland side of China. Literature records and monitoring results of 2000-2001 confirmed that the lower section of the Dongjiang had been contaminated by organic and inorganic pollutants. Statistical analyses showed that the increases of total cadmium, copper and zinc in the surface layer of sediment of Hong Kong reservoirs from 1994 to 2001 were positively correlated (significant at p<0.05) with those in the surface layer of sediments of the lower Dongjiang. Recent microbiological survey revealed that pathogens such as Salmonella spp., Vibro spp., Giardia lamblia and Cryptosporidium parvum appeared occasionally in water samples of the Dongjiang and Hong Kong reservoirs. While analytical results found that currently most of the heavy metals, trace organics and microbes were removed by the drinking water treatment plants in Hong Kong, the long-term health risk of drinking water contamination should not be overlooked. The Water Supplies Department of Hong Kong is recommended to intensify its water quality monitoring program to cover pathogenic bacteria and parasites in watercourses and reservoirs.

Sarcoidosis of the gingiva--a case report

Involvement of oral tissues by sarcoidosis is uncommon. We present a case of sarcoidosis involving the gingivae of a 60-year-old woman. The patient presents with an 18-month history of localized areas of gingival redness and swelling. She also has a previous history of sarcoidosis.

'Sites' of resistance: alternative websites and state-society relations

Much attention has been focused on Singapore's attempt to use information technology to build a knowledge-based economy. This paper examines the implications of the unintended consequences of the Internet in the restructuring of state and society relations in Singapore. We use the data on Singapore-based and Singapore-related websites to show (a) the diversity of positions expressed by civil society organizations, fringe groups and even mainstream segments of society; (b) the negotiation process between the state and civil society over various rights and how developments in cyber-space have implications for 'reality'; (c) how censorship and content regulation itself is a more complex multi-dimensional process such that while local politics is regulated, the multi-ethnic character of the resident population has led to greater religious tolerance such that religious groups banned in some countries have found a safe haven in Singapore and have used the city-state as a strategic Internet node.

Chemical contamination of the East River (Dongjiang) and its implication on sustainable development in the Pearl River Delta

A recent survey reveals that water quality and river sediments of Dongjiang (the East River) have been mildly contaminated by heavy metals and organic chemicals, such as copper, lead, PCBs, PAHs and HCHs. According to photogrammertic surveys, the sources of contamination are closely related to human activities, such as domestic and industrial discharges, agricultural chemical applications and soil erosion due to deforestation. The level of water and sediment contamination is most serious at the mid-river section near the urban of Weizhou. Due to natural dilution and diffusion, the levels of contamination are slightly decreased at the medium low section of the River near Qiaotou and Matan. Nevertheless, the levels of contamination increase again in the lower river section near Shenzhen, which is a highly developed economic zone. Since Dongjiang is the major source of potable water supply for Hong Kong (nearly 80% of potable water of Hong Kong is abstracted from Dongjiang) and the other parts of the Pearl River Delta (PRD), such organic and inorganic pollution merit concern. Ironically, most of the industrial and commercial activities in the watershed of Dongjiang are business investments of Hong Kong citizens. Cross-border environmental efforts should be enhanced with collaboration of different jurisdictions to achieve targets of regional sustainability.

Organization of ribosomal RNA genes from a Loofah witches' broom phytoplasma

Using the technique of integrative mapping with three vectors carrying chromosomal rDNA sequences, one of two rRNA operons of loofah witches' broom (LfWB) phytoplasma was constructed. This is the first complete rRNA operon of a phytoplasma to be reported. The operon has a context of 5'-16S-23S-5S-3' with a tRNA(Ile) gene in the ITS and tRNA(Val) and tRNA(Asn) genes downstream from the 5S rRNA gene. Although the other operon has not been cloned, the DNA sequence of a PCR-amplified product shows that it has no tRNA(Ile) gene in the ITS region. The complete nucleotide sequences of 16S, 23S, and 5S rDNA are 1538, 2864, and 113 bp, respectively. Five -10-like sequences, but no -35 sequences, were found within a 494-bp leader region. There was a TG dinucleotide two nucleotides upstream from each -10-like sequence. The existence of a TG dinucleotide at this position has been reported to enhance the efficiency of a promoter without a -35 region. The regions immediately flanking the 5' and 3' ends of 16S and 23S rDNA can form long basepaired stems that contain sites for processing by RNase III. No obvious sequence for a rho-dependent or rho-independent termination site was found downstream from the tRNA(Asn) gene. The transcription may stop within a pyrimidine-rich region, as has been reported for several polypeptide-encoding genes and rRNA operons of archaeobacteria. The presence of the tRNA genes downstream from the 5S rRNA gene in the rRNA operon of LfWB phytoplasma further supports the hypothesis that phytoplasmas are phylogenetically closer to acholeplasmas than to mycoplasmas. The phylogenetic relatedness of LfWB phytoplasma to other phytoplasmas is discussed on the basis of the nucleotide sequence of rRNA genes and ITS.

The fliU and fliV genes are expressed as a single ORF in Salmonella choleraesuis

A DNA fragment carrying flagellar genes was cloned from Salmonella choleraesuis. Compared to the corresponding DNA fragment of Salmonella muenchen, this fragment contained three ORFs instead of four shown in S. muenchen. The DNA sequence data showed that there was an insertion of nucleotide C in the ORF of the S. choleraesuis fliU gene, which resulted in the disappearance of a termination codon downstream. The recombinant plasmid pFU11 containing the coding region of the fliU gene made by PCR on S. choleraesuis genomic DNA was constructed and expressed in Escherichia coli in the presence of IPTG. As expected, a 45 kDa protein band was observed on a SDS-PAGE gel, in contrast to two with each having about a half of the molecular weight. These results demonstrated that the DNA sequence encoding one protein (FliU) in S. choleraesuis corresponded to the DNA sequence encoding two proteins (FliU and FliV) in S. muenchen. The protein encoded by this single ORF might carry out the functions of two separated proteins by folding in such a way that its conformation could function like two interdependent protein subunits.

Meningococcal disease in South African goldmines--epidemiology and strategies for control

OBJECTIVES

To describe the epidemiology of meningococcal disease in South African goldmines and to suggest strategies for the prevention and control of further outbreaks.

DESIGN

We prospectively investigated a meningococcal outbreak that occurred in 1996 and describe the control measures that were implemented. In addition, we conducted a retrospective analysis of routinely collected data on meningococcal disease in these mines from 1972 to 1996.

SETTING

Four goldmines in Gauteng, employing 30,000 workers who live in hostels.

SUBJECTS

All cases of meningococcal disease at the mine hospital.

RESULTS

Between 1972 and 1976, 588 cases were diagnosed, with peaks in 1972 (203 cases, 727/100,000) and 1975 (147 cases, 564/100,000). Since 1978 less than 5 cases have been reported in most years, but smaller outbreaks occurred in 1990 (30 cases, 89/100,000) and 1996 (14 cases, 50/100,000). The 1996 outbreak (group A, clone I-1) was part of a larger outbreak in Gauteng that originated in Mozambique and began in one mine in July 1996, after which a mass vaccination campaign was implemented. This was followed by a smaller outbreak among non-vaccinated workers at an adjacent mine. Five patients were new recruits.

CONCLUSIONS

Despite a dramatic reduction in meningococcal disease over the last 25 years due mainly to changes in the work force, there are still outbreaks in this community. Those most at risk are young men who are new to the industry. Suggestions for prevention include effective surveillance, routine vaccination of new recruits and a rapid response to outbreaks, with mass vaccination and provision of chemoprophylaxis to close contacts.

Liquid phase parallel synthesis of guanidines

Combinatorial synthesis of N,N'-di(Boc)-Protected guanidines containing piperazine and pyrrolidine scaffolds has been developed. We initiate a preliminary study on the reactivity of several guanylating reagents with soluble polymer-bound diamines in liquid phase. Guanidines are liberated from the polymer support under mild conditions in high yields and high purity by simple precipitation and washings. This combinatorial liquid-phase methodology proves to be a useful tool for constructing guanidine libraries containing diamine scaffolds.

Meningitis in a community with a high prevalence of tuberculosis and HIV infection

OBJECTIVES

To evaluate the spectrum of aetiologies, and distinguishing clinical and laboratory features, of meningeal infection in a community with a high prevalence of tuberculosis (TB) and HIV infection.

SETTING

A hospital serving mineworkers, originating from rural areas of Southern Africa.

DESIGN

Prospective cohort of 60 consecutive lumbar punctures (LPs), performed for suspected meningitis.

MEASUREMENTS

Clinical history and examination; concurrent cerebrospinal fluid (CSF) and blood samples; mortality status six months after entry to study.

RESULTS

38 of 57 patients (66.7%) were HIV-1 positive, 59.5% of whom had a CD4 count <200 cells/mm3. Nine patients had tuberculous meningitis (TBM) and two had tuberculomas; four developed disease while on TB therapy. There was one case of multidrug, and two of isoniazid-resistant TBM. There were nine episodes of cryptococcal meningitis (seven patients), nine of aseptic meningitis, two of neurosyphilis and 20 normal LPs, including four with AIDS dementia complex (ADC). Ten patients with meningococcal infection, part of a larger outbreak, were significantly younger (p=0.004). All patients with tuberculous, cryptococcal (most immune-suppressed p<0.001) and aseptic meningitis were HIV-1 positive. Within six months, 19 patients had died. Death was associated with HIV positivity (p=0.004), low CD4 count (p<0.001) and a diagnosis of cryptococcal meningitis, CNS TB or ADC.

CONCLUSION

HIV has a major impact on the burden of disease and mortality, with a predominance of opportunistic chronic meningitides, despite a meningococcal outbreak, in this community. Of concern is the development of TBM despite therapy, and the emergence of drug-resistant strains.

Favorable scanning electron microscopic findings of stapled saphenous vein-carotid artery anastomoses

BACKGROUND

In the progress toward "off-pump" endoscopic coronary artery surgical procedures, new techniques for coronary artery anastomoses are being developed. One such approach is the use of nonpenetrating titanium clips. We evaluated the quality of anastomoses achieved using this technique in a porcine model of saphenous vein-carotid artery grafting using scanning electron microscopy.

METHODS

Bilateral saphenous vein-carotid artery interposition grafts were implanted in 10 "white race" pigs, using the nonpenetrating clips in one side of the neck and conventional hand suturing on the opposite side. One week after operation, the grafts were harvested.

RESULTS

All grafts were patent 7 days after operation, and 40 anastomoses underwent scanning electron microscopic study. In all samples, the luminal surfaces of both the carotid artery and vein graft were covered by a continuous layer of endothelial cells up to the anastomosis. Anastomotic sites in all clipped samples and most of the sutured anastomoses were completely endothelialized, and anastomotic clefts were indistinguishable. However, in 25% of sutured specimens, the suture material remained clearly visible inside the lumen of the vessel, and the subendothelial matrix remained exposed, with extensive fibrin, red blood cells, and platelet deposition on its surface.

CONCLUSIONS

Because the endothelial coverage consistently appeared to be complete and the subendothelial matrix was not exposed, it is likely that the risk of early anastomotic thrombosis is reduced by using the nonpenetrating titanium clips.

Single-voxel proton MR spectroscopy of nonneoplastic brain lesions suggestive of a neoplasm

BACKGROUND AND PURPOSE

MR spectroscopy is used to characterize biochemical components of normal and abnormal brain tissue. We sought to evaluate common histologic findings in a diverse group of nonneoplastic diseases in patients with in vivo MR spectroscopic profiles suggestive of a CNS neoplasm.

METHODS

During a 2-year period, 241 patients with suspected neoplastic CNS lesions detected on MR images were studied with MR spectroscopy. Of these, five patients with a nonneoplastic diagnosis were identified retrospectively; a sixth patient without tissue diagnosis was added. MR spectroscopic findings consistent with a neoplasm included elevated choline and decreased N-acetylaspartate and creatine, with or without detectable mobile lipid and lactate peaks.

RESULTS

The histologic specimens in all five patients for whom tissue diagnoses were available showed significant WBC infiltrates, with both interstitial and perivascular accumulations of lymphocytes, macrophages, histiocytes, and (in one case) plasma cells. Reactive astrogliosis was also prominent in most tissue samples. This cellular immune response was an integral component of the underlying disorder in these patients, including fulminant demyelination in two patients, human herpesvirus 6 encephalitis in one patient, organizing hematoma from a small arteriovenous malformation in one patient, and inflammatory pseudotumor in one patient. Although no histologic data were available in the sixth patient, neoplasm was considered unlikely on the basis of ongoing clinical and neuroradiologic improvement without specific therapy.

CONCLUSION

Nonneoplastic disease processes in the CNS may elicit a reactive proliferation of cellular elements of the immune system and of glial tissue that is associated with MR spectroscopic profiles indistinguishable from CNS neoplasms with current in vivo MR spectroscopic techniques. Such false-positive findings substantiate the need for histologic examination of tissue as the standard of reference for the diagnosis of intracranial mass lesions.

Fulminant progression of demyelinating disease after valproate-induced encephalopathy

We report the clinical, radiologic, and pathologic features of a patient who had fulminant demyelinating disease and who experienced acute progression of his disease after an episode of valproate-induced hyperammonemic encephalopathy. The role hyperammonemia played in the progression of the demyelination is uncertain. This case raises concern of a possible risk with the use of valproic acid in the subset of patients with fulminant demyelinating disease.

Contrast media of high and low molecular weights in the detection of recurrent herniated disks

PURPOSE

Our goal was to compare contrast enhancement of recurrent herniated disk fragments and scar after intravenous injection of a new high-molecular-weight contrast medium, Gadomer 17 (gadomer), with that after injection of a low-molecular-weight contrast medium, (gadopentetate dimeglumine).

METHODS

Recurrent herniated disks were modeled in dogs by placing a fragment of intervertebral disk cartilage in the epidural space at laminectomy. MR imaging was performed with one of the contrast media at 20 and 50 days and with the other medium at 22 and 52 days. The changes in signal intensity from baseline in the disk fragment and in the adjacent scar tissue was measured at 2, 22, and 45 minutes. Differences were tested for significance with a student t-test.

RESULTS

At 50 days after surgery, signal intensity in the intervertebral disk fragment increased by an average of 0.52 at 2 minutes after injection of gadomer and by an average of 0.90 after injection of gadopentetate. For scar, the increases in signal intensity were 1.41 (gadomer) and 1.62 (gadopentetate). At 22 and 45 minutes after injection, the signal intensity change in the disk fragment continued to be significantly greater after gadopentetate than after gadomer injection. In comparison with the changes at 50 days, both scar and disk fragment tended to show greater signal intensity changes at 20 days. Signal intensity changes in the disk fragments were significantly less after gadomer than after gadopentetate. Signal intensity changes in scar were slightly less with gadomer than with gadopentetate.

CONCLUSION

Greater contrast is achieved between scar and recurrent herniated disk with a higher-molecular-weight contrast medium than with one of lower molecular weight. The difference between the high- and low-molecular-weight contrast media increases with maturation of the scar tissue.

CuTira brachytherapy: a new combination of radioactive copper isotopes and the hypoxic cytotoxin, tirapazamine, for targeted tumor therapy

We previously showed a significant enhancement of tirapazamine-induced cytotoxicity and DNA damage after binding with copper. This result suggests that conjugates of tirapazamine with radioactive copper, i.e., 64Cu and 67Cu, may offer potential for targeted therapy of a wide range of advanced stage tumors including a possible treatment for patients with solitary hepatocellular carcinoma by intrahepatic arterial infusion. Major supporting considerations include: (a) tirapazamine having a high selective toxicity against hypoxic cells; (b) the nature of radioactive decay of these copper isotopes and obtainable high specific activity; and (c) simple procedure for the production of copper-tirapazamine complex.

Bilateral choroidal metastases as the initial presentation of a small breast carcinoma: a case report

Most ocular tumors metastasize from systemic origins in breast carcinoma in females, and bronchial carcinoma in males. Here, we report a case of choroidal carcinoma metastasis from the breast with visual problems being the only initial manifestations. In this case, both eyes were involved at almost the same time, with initial manifestation of blurred vision which progressed to complete visual loss. At first, the patient was diagnosed with malignant melanoma, and enucleation of the right eye was performed in another hospital. However, the tumor had already metastasized rapidly to numerous organs, including the lungs, brain and bone, although it had not affected the liver. Clinical presentations were, therefore, not compatible with those of malignant melanoma, which has usually been reported to metastasize to the liver. Persistent hypercalcemia and raised carcinoembryonic antigen (CEA) concentrations prompted investigations into the possibility of systemic malignancy. A very small breast nodule was finally located by thorough physical examination, and a lumpectomy was performed. A detailed review of the histopathology showed the tumors from the breast and the right eye to have the same origin. Simultaneous bilateral choroidal metastases from other malignancies is not uncommon; however, it is quite rare for breast carcinoma to present with visual problems as a first manifestation. Detailed history taking and physical examination are therefore essential when searching for a primary tumor, so that appropriate therapy can be given earlier.

Epstein-Barr virus LMP1 modulates the malignant potential of gastric carcinoma cells involving apoptosis

About 10% of gastric carcinomas including lymphoepithelioma-like carcinoma and adenocarcinoma are associated with Epstein-Barr virus (EBV) infection. In EBV-associated gastric carcinomas, the tumor cells express Epstein-Barr nuclear antigen 1 (EBNA-1) but not EBNA-2, -3A, -3B, or -3C, leader protein, or latent membrane proteins (LMPs) because of gene methylation. Only a few exceptional cases have LMP1 expression in tumor cells as demonstrated by immunohistochemical studies. To elucidate the biological effects of LMP1 and the significance of its restricted expression in EBV-associated gastric carcinomas, the LMP1 gene was transferred into EBV-negative gastric carcinoma cell lines (SCM1 and TMC1) and into EBV-negative nasopharyngeal carcinoma (NPC) cells (HONE-1) as a control. The biological effects of LMP1 in gastric carcinoma cells were monitored in vitro and in vivo. These results showed that the consequence of LMP1 expression is a growth enhancement in NPC cells, but it is a growth suppression in gastric carcinoma cells. The LMP1-expressing gastric carcinoma cells had a reduced growth rate, colony-forming efficiency, mean colony size, and tumorigenicity and a lower malignant cytological grade. The reduced growth rate, colony-forming efficiency, and mean colony size were partially reversible in vitro with treatment with LMP1 antisense oligonucleotide. In addition, enhanced apoptosis was found in the LMP1-expressing gastric carcinoma cells. This suggests that LMP1 may negatively modulate the malignant potential of gastric carcinoma cells via an enhancement of apoptosis. We concluded that the restriction of LMP1 expression in EBV-associated gastric carcinomas may lead to a growth advantage for tumor cells by avoiding LMP1 apoptotic effects and immunologically mediated elimination.

Cytochrome oxidase in Alzheimer's disease: biochemical, histochemical, and immunohistochemical analyses of the visual and other systems

Defects in oxidative metabolism have been implicated in Alzheimer's disease (AD). The present study evaluated the level of cytochrome oxidase (C.O.), an indicator of neuronal oxidative capacity, in various brain regions of post-mortem AD and control patients. We found a statistically significant reduction in C.O. levels in all cortical areas examined, including the primary and secondary visual cortices. In addition, all layers of the dorsal lateral geniculate nucleus and sublaminae of the primary visual cortex in AD cases examined suffered a reduction in their relative C.O. activity and protein amount. Our results suggest a generalized suppression of oxidative metabolism throughout the cortex, as well as in a major subcortical visual center in AD. Such hypometabolism may form the basis for not only deficits in higher cortical functions, but also a variety of visual dysfunctions known to occur in AD.

Malignant lymphomas of sinonasal region, including cases of polymorphic reticulosis: a retrospective clinicopathologic analysis of 34 cases

BACKGROUND

Lymphomas occurring in nasal cavities and paranasal sinuses are uncommon neoplasms in Western, but are reported to be higher in Oriental, countries. A retrospective study was performed to analyze the clinical and pathological characteristics of sinonasal lymphomas/polymorphic reticulosis at Taichung Veterans General Hospital during a 14-year period.

METHODS

At Taichung Veterans General Hospital, 37 patients with sinonasal lymphomas (including three patients with polymorphic reticulosis) were seen from November 1982 through September 1996. Excluding three patients without sufficient data, a total of 34 patients with their clinical records were reviewed. Clinical information regarding characteristics of the tumors, histological studies, treatment modalities and follow-up was collected for analysis.

RESULTS

The 34 patients who underwent review showed a male-to-female ratio of 2.1:1. Median age was 60 years (range 13-83 years). The most common symptoms were nasal obstruction, nasal discharge/rhinorrhea and epistaxis. Median duration of symptoms at the time of diagnosis was two months. The most frequently involved sites were nasal cavities (right more than left side). There were 31 non-Hodgkin's lymphomas and three polymorphic reticuloses. The pathological classifications revealed 13 diffuse large cell lymphomas, 14 diffuse mixed small and large cell lymphomas and four pleomorphic T-cell lymphomas. Of the 21 adequately staged patients, 13 patients were in stage I; four, stage II; two, stage III and two, stage IV. The immunophenotypic study was performed in 20 patients. Eighteen (90%) of them were T-cell lymphomas and only two cases (10%) derived from B-cell. Though approach to therapy and follow-up periods varied during the time period covered by this study, the differences in survival according to treatment modalities were not statistically significant. The follow-up period ranged from 9 days to 130 months. The mean survival was 84.2 months. The overall five-year survival rate was 63%.

CONCLUSIONS

The majority of the cases here were T-cell lymphomas. Most histologic grading by Working formulation belonged to the intermediate grade. Optimal treatment for such a group of patients still has no consensus, but adequate local control is important. If diagnosed and treated early, primary sinonasal lymphomas can be associated with a favorable outcome even with local treatment alone.