Abstract P4-12-04: Breast cancer subtype, age and lymph node status as predictors of local recurrence following breast-conserving therapy

Purpose/Objectives: Advances in breast-conserving therapy (BCT) have yielded local control rates comparable or superior to those of mastectomy. Here, we sought to identify risk factors associated with isolated local recurrence (LR) following BCT.

Materials/Methods: This study included a multi-institutional cohort of 2,233 consecutive breast cancer patients who underwent BCT between 1998 and 2007. Patient characteristics and disease parameters were stratified by age, subtype and nodal status. Biologic subtype was approximated by receptor status and tumor grade. No patients received HER2/neu-directed therapy. The association of clinicopathologic features with LR was evaluated using Cox proportional hazards regression models.

Results: At a median follow-up of 106 months, 69 LR events (3.1%) were observed. Among the overall cohort, 10-year freedom from LR was 95.9%. On univariate Cox regression analysis, risk factors associated with LR included subtype other than luminal A (hazard ratio [HR] for luminal B = 3.01, HER2 = 6.29, triple negative [TNBC] = 4.72; p<0.001 for each), younger age (HR of oldest versus youngest quartile = 0.43; p=0.005), regional lymph node involvement (HR for 4-9 involved nodes = 3.04; >9 nodes = 5.82; p<0.01 for each), positive resection margins (HR = 2.43; p=0.005), and high-grade disease (HR = 5.37; p <0.001). Presence of LVI (HR = 1.56; p=0.06) or 1-3 involved nodes (HR = 1.55; p=0.07) approached significance. Multivariate Cox regression demonstrated an association with LR among those with non-luminal A subtypes (HR for luminal B = 2.64, HER2 = 5.42, TNBC = 4.32; p<0.001 for each), younger age (HR for age >50 = 0.56; p=0.01), and any nodal disease (HR=1.06 per involved node; p<0.004).

Conclusions: BCT yields favorable outcomes for the large majority of patients, although increased LR was observed among those with non-luminal A subtypes, younger age, and increasing lymph node involvement. Risk factors for LR following BCT appear to be converging with those following mastectomy in the current era.

Citation Format: Braunstein LZ, Taghian AG, Niemierko A, Salama L, Capuco A, Wong JS, Punglia RS, Bellon JR, MacDonald SM, Harris JR. Breast cancer subtype, age and lymph node status as predictors of local recurrence following breast-conserving therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-04.

Abstract P3-17-07: Improved long-term outcomes of breast-conserving therapy for women with ductal carcinoma in situ

Purpose: Improved mammographic and surgical techniques and pathologic evaluation, particularly greater attention to achieving negative margins, have resulted in decreased local recurrence rates for patients with ductal carcinoma in situ (DCIS). This is an updated analysis of local outcomes after breast-conserving surgery (BCS) and adjuvant radiation therapy (RT) at a single institution in the modern era.

Methods and Materials: We retrospectively reviewed the records of 245 women treated for DCIS with BCS and RT between 2001 and 2007. Competing risk analysis was used to calculate local recurrence (LR) as a first event with the development of a second non-breast malignancy, contralateral breast cancer, and death as competing first events. The median age at diagnosis was 54 (range, 32-84) and 174 (93%) women had estrogen receptor (ER) and/or progesterone receptor (PR) positive disease. Ninety-five (39%) were grade III. Specimen radiograph during surgery was obtained for 223 women (91%) and post-operative mammogram for 102 (42%). Half underwent more than one excision. The institutional goal for margins during the study period was 3 mm or greater; final margins were >2 mm in 221 (90%). All received adjuvant radiation therapy to the whole breast (median whole breast dose: 4400; range, 4000 - 5220) and nearly all (99%) received a boost to the surgical cavity (median boost dose: 1600; range, 800 – 1800). Among patients with ER and/or PR+ disease, 105 (60%) received adjuvant hormonal therapy.

Results: At a median follow-up of 10.6 years, 4 patients had a LR (2 DCIS, 2 invasive ductal carcinoma) as a first event with a cumulative LR incidence of 0.0% and 1.5% at 5 and 10 years, respectively. The 5 and 10-year cumulative incidence of the competing first events is seen in the table below. Twenty women developed a contralateral breast cancer (CBC; 8 DCIS, 12 invasive carcinoma), 13 were diagnosed with a second non-breast malignancy (3 endometrial, 2 fallopian tube, 1 gallbladder, 1 leukemia and thyroid, 4 lung, 1 ovarian, and 1 uterine), and 7 died. Family history, age at diagnosis, and receipt of hormonal therapy were not significantly associated with the development of CBC on univariable analysis (all p>0.05).

Incidence of local recurrence and competing eventsEvent5-year cumulative incidence10-year cumulative incidenceLocal recurrence0.0%1.5%Contralateral Breast Cancer2.5%7.9%Second non-breast malignancy2.6%4.5%Death1.2%3.5%

Conclusions: With longer follow-up, our rates of local recurrence following breast-conserving therapy for DCIS remain very low (1.5% at 10 years). The vast majority of patients had >2 mm margins, specimen radiographs, and received a tumor bed boost. The majority (60%) of patients with hormone receptor positive disease received adjuvant endocrine therapy. The 10-year incidence of CBC was higher than expected. Predisposing factors for the development of CBC are worthy of investigation.

Citation Format: Warren LE, Chen Y-H, Halasz LM, Capuco A, Bellon JR, Brock JE, Punglia RS, Wong JS, Harris JR. Improved long-term outcomes of breast-conserving therapy for women with ductal carcinoma in situ [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-17-07.

The State of Lipid Control in Patients with Diabetes in a Public Health Care Centre

Achieving treatment targets has been difficult in treating diabetic patients. This cross-sectional study describes the lipid profiles of patients with diabetes mellitus at a public primary health care centre in Sarawak, Malaysia. The targets for lipid control were based on the International Diabetes Federation recommendation (2002). 1031 patients (98% Type 2 Diabetes) were studied. Fasting lipid profiles were available in 990 (96%) patients. The mean total cholesterol was 5.3 ± 1.0 mmol/L, Triglycerides 1.90 ± 1.26 mmol/L, HDL-C 1.28 ± 0.33 mmol/ L and LDL-C 3.2 ± 0.9 mmol/L. Overall, 22% of patients achieved the treatment target for LDL-C level <2.6mmol/L. 67% of patients had HDL-C > 1.1 mmol/L and 42% of patients had a target TG level below 1.5 mmol/L. Of the 40% of patients who received lipid-lowering drug, 17% achieved LDL-C target, 50% had LDL-C 2.6-4.4mmol/ L and 33% have LDL-C > 4.0 mmol/L. For the remaining 60% not receiving any lipid lowering therapy, 68% had LDL-C between 2.6-4.0 mmol/L and 7% had LDL-C level > 4 mmol/L. Dyslipidemia is still under-treated despite the availability of effective pharmacological agents and the greatly increased risk of cardiovascular diseases in diabetic patients. Asia Pac J Public Health 2007; 19(3): 16-21.

Adjuvant hepatic intra-arterial iodine-131-lipiodol following curative resection of hepatocellular carcinoma: a prospective randomized trial

BACKGROUND

The purpose of the present study was to determine whether intrahepatic injection of (131)I-lipiodol (Lipiodol) is effective against recurrence of surgically resected hepatocellular carcinoma (HCC).

METHODS

From June 2001 through March 2007, this nationwide multi-center prospective randomized controlled trial enrolled 103 patients 4-6 weeks after curative resection of HCC with complete recovery (52: Lipiodol, 51: Control). Follow-up was every 3 months for 1 year, then every 6 months. Primary and secondary endpoints were recurrence-free survival (RFS) and overall survival (OS), respectively, both of which were evaluated by the Kaplan-Meier technique and summarized by the hazard ratio (HR). The design was based on information obtained from a similar trial that had been conducted in Hong Kong.

RESULTS

The Lipiodol group showed a small, and nonsignificant, improvement over control in RFS (HR = 0.75; 95 % confidence interval [95 % CI] 0.46-1.23; p = 0.25) and OS (HR = 0.88; 95 % CI 0.51-1.51; p = 0.64). Only two serious adverse events were reported, both with hypothyroidism caused by (131)I-lipiodol and hepatic artery dissection during angiography.

CONCLUSIONS

The randomized trial provides insufficient evidence to recommend the routine use of (131)I-lipiodol in these patients.

Prevalence of asymptomatic atrial fibrillation in malaysian patients with hypertension

Atrial fibrillation (AF) is usually asymptomatic and often associated with established cardiovascular risk factors such as hypertension. The prevalence atrial fibrillation in patients admitted to Malaysian hospitals has been determined, but asymptomatic atrial fibrillation (AAF) in hypertensive patients in the primary care setting is not established. This study reports the prevalence of AAF in hypertensive patients in Malaysia, in a primary care setting. The overall prevalence of AAF was 0.75% with no differences between the gender. The prevalence of AAF increases with age - in the age groups of 30-39, >40-49, >50-59, >60-69, 70-79 and >80 years old were 0%, 0.17%, 0.35%, 2.32%, 2.59%, and 0% respectively. Hypertensive patients with age of ≥ 61 year old were associated with a probability of 10.6 times higher for AAF. We suggest the age threshold to screen for AAF to be age of 60. It is estimated that there are 49,029 Malaysians with AAF in 2010. A large population is at risk of AAF-related complications. There is justification for an even greater emphasis on diagnostic, primary and secondary prevention strategies.

Randomized clinical trial of open hepatectomy with or without intermittent Pringle manoeuvre

BACKGROUND

The intermittent Pringle manoeuvre (IPM) is commonly applied during liver resection. Few randomized trials have addressed its effectiveness in reducing blood loss and the results have been conflicting. The present study investigated the hypothesis that IPM could reduce blood loss during liver resection by 50 per cent.

METHODS

Between May 2008 and April 2011, patients who underwent elective open hepatectomy were randomized into an IPM or no Pringle manoeuvre (NPM) group and stratified according to the presence or absence of cirrhosis. Data on demographics, type of hepatectomy, operative blood loss, duration of operation, mortality, morbidity and postoperative liver function were recorded and analysed. The primary endpoint was operative blood loss.

RESULTS

There were 63 patients in each group. Median (range) operative blood loss was 370 (50-3600) ml in the IPM group versus 335 (40-3160) ml in the NPM group (P = 1·000). There were no differences in blood loss in different phases of the operation, blood loss per area of liver transected or blood transfusion rate, nor in total duration of operation or liver transection time. Postoperative serum alanine aminotransferase levels were higher in the IPM group (P < 0·001). There were more postoperative complications in the IPM group (41 versus 24 per cent; P = 0·036).

CONCLUSION

The IPM did not reduce blood loss, but was associated with raised levels of postoperative liver parenchymal enzymes and more complications.

REGISTRATION NUMBER

NCT00730743 (http://www.clinicaltrials.gov).

Polymyositis and dermatomyositis in Sarawak: a profile of patients treated in the Sarawak General Hospital

We performed a cross-sectional study of the demography, clinical and laboratory features of patients with polymyositis and dermatomyositis followed up in our centre from 2006 to 2009. There were 12 cases, with the majority of them (58.3%) being woman. They have a mean age of 57.8 years and mean disease duration of 11.83 (SD 9.92) months. Our patients comprised of multi-ethnic groups with predominantly Chinese (83.3%), Sarawak natives (8.3%) and Malays (8.3%). They have a mean lag time to diagnosis of 3.67 (SD 4.27) months. Nine (75%) patients had dermatomyositis and 3(25%) had polymyositis. The common clinical manifestations found in our patients were proximal myopathy (100%), neck weakness (33.3%), dysphagia (33.3%) and interstitial lung disease (33.3%). For the nine patients with dermatomyositis, the most common dermatological manifestations were shawl sign (88.9%) and V sign (88.9%). Muscle enzymes were raised in 91.7% of patients. Electromyographies were carried out in four patients, and only one of our patients had muscle biopsy. Only 41.7% of our patients have positive ANA. The majority received prednisolone (100%) and hydroxychloroquine (58.3%). Malignancy occurred in five (three nasopharyngeal carcinomas, one sigmoid colon cancer and one lung cancer) out of the nine dermatomyositis patients but none in the polymyositis group. The mortality rate in our group was 4(33.3%) over the 4-year period. This study demonstrated the rarity of PM/DM in our centre with considerable lag time to diagnosis in our patients. Despite lack of muscle biopsy in our centre, our centre achieved appropriate diagnosis and management of PM/DM.

Abstract P1-15-03: Eight-Year Update of a Prospective Study of Wide Excision Alone for Ductal Carcinoma In Situ (DCIS) of the Breast

Background: The need for radiation therapy (RT) in conservatively managed DCIS is a source of ongoing debate. This is an updated analysis of a phase II prospective study of wide excision alone for DCIS. The study was activated in May 1995 and closed in July 2002 following accrual of 158 patients because the number of local recurrences (LR) met the predetermined stopping rules. The objective of the analysis is to update the distribution and cumulative incidence of events (LR, contralateral breast cancer [CBC], second malignancy and death from other causes). Materials and Methods: A total of 158 patients had DCIS with predominant nuclear grade 1 or 2, a mammographic extent of ≥2.5 cm, and excision with final microscopic margins of ≥1 cm or a re-excision without residual DCIS. Tamoxifen was not permitted. The results presented are from the 8-year analysis (8-year minimum potential follow-up time). Twenty-six patients without recurrence who were followed less than 8 years were excluded from the analysis as were 7 first events (4 LR) that occurred beyond 8 years of follow-up; the analysis thus includes 132 patients and 36 first events. Cumulative incidence curves were generated to assess the rates of LR or other events. Median follow up time was 10 years. Results: Overall, 36/132 patients (27%) had a first event as of April 2010. Of these 36 events, 19 were LR, 13 were CBC, 1 was a second malignancy, and 3 were deaths from other causes. Of the 19 LR, 13 (68%) were DCIS only and 6 (32%) were invasive. Fourteen occurred in the same quadrant and 5 were elsewhere in the ipsilateral breast. The 8-year estimated cumulative incidence of LR was 14.4% (95% CI: 8.4-20.4%). For all other events, the 8-year estimated cumulative incidence was 12.9% (95% CI: 3.6-13.1%).

The estimated annual percentage rates of LR, CBC, and other events were 2.1%, 1.5% and 0.4%, respectively.

Discussion: The results of this prospective study demonstrate a substantial and ongoing risk of LR and CBC in patients with small, nuclear grade 1 or 2 DCIS treated with wide excision with margins of ≥1cm in the absence of RT. Most LRs occurred in the same quadrant, rather than elsewhere in the breast, suggesting that excision alone is inadequate even for this highly selected population. Further study is warranted to determine if there is a subgroup of DCIS patients with nuclear grade 1 or 2 disease who are at low enough risk of LR following wide excision that RT can be omitted safely.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-15-03.

Systemic lupus erythematosus pregnancies: the Sarawak experience and review of lupus pregnancies in Asia

We performed a cross-sessional study of all systemic lupus erythematosus (SLE) pregnancies during a 4-year period (2006-2009) to describe the clinical features, maternal and foetal outcomes in our centre. There were 48 pregnancies in 44 women with SLE. Our patients have a mean age of 30.0 years (SD 6.36) and a mean disease duration of 40.67 months (SD 48.23). Our patients have complicated pregnancies: 32.7% have SLE flares, 17.3% have preeclampsia and 48.9% needed caesarean sections. There were 20.0% foetal losses and 17.8% preterm deliveries in our patients. SLE flares contributed to 60.0% of foetal losses in our patients. Lupus pregnancies in our centre generally have a good maternal and foetal outcome comparable to developed countries in Asia. The low incidence of APS, the high usage of hydroxychloroquine and the high SLE remission rate in our patients prior to conceptions contributed to the good outcome.

The many faces of intraosseous haemangioma: a diagnostic headache

Intraosseous haemangioma constitutes less than ten percent of all primary bone neoplasms. Approximately 75 percent occur in the calvarium or vertebrae, with long bones, short tubular bones and ribs constituting the rest. We describe a 52-year-old woman who presented with left knee pain for 4-5 years and loss of weight over one week. An initial radiograph of the knee showed several well circumscribed isodense lesions with sclerotic rims in the medullary cavity of the distal femur and diaphysis of the left tibia. There were also lucent lesions with a slightly sclerotic rim in the diaphysis of the left tibia and proximal left fibula. In view of the clinical presentation and radiological findings, extensive investigations were made to rule out metastases and multiple myeloma. An open biopsy with segmental osteotomy of the left mid fibular lesion revealed an intraosseous haemangioma.

Systemic lupus erythematosus pregnancies: a case series from a tertiary, East Malaysian hospital

We performed a retrospective study of all systemic lupus erythematosus (SLE) pregnancies during a two-year period (2006–2007) to describe the clinical features, maternal and foetal outcomes in our centre. There were 17 pregnancies in 16 women with SLE. Our patients have a mean age of 28.31 years (SD 5.24) and a mean disease duration of 38.62 months (SD 38.03). Our patients have complicated pregnancies: 35.3% have SLE flares, 21.1% have preeclampsia and 47.4% needed caesarean sections. There were 15.8% foetal losses and 12.5% preterm deliveries in our patients. All the foetal losses occurred in patients with severe SLE flares during pregnancies. Lupus pregnancies in our centre generally have a good maternal and foetal outcome comparable with developed countries. The low incidence of antiphospholipid syndrome, the high usage of hydroxychloroquine and the high SLE remission rate in our patients before conceptions are the possible factors contributing to the good outcome.

The pattern and clinical manifestations of rheumatoid arthritis in Sarawak General Hospital

The aim of our study is to describe the pattern, clinical features, treatment regimes, and disease activity among the patients treated for rheumatoid arthritis (RA) in the Sarawak General Hospital. We performed a cross-sectional study of all patients with a diagnosis of RA who received treatment at the General Medical Clinic and the Rheumatology Clinic in Sarawak General Hospital over a 1-year period from 1st June 2006 to 31st May 2007. Demographic data, clinical features, and disease activity of all 154 patients were collected for statistical analysis. Rheumatoid arthritis afflicts all the major racial groups in Sarawak including the native population. Our patients have a mean disease duration of 5.4 years (SD 5.69) and a mean duration of delay in diagnosis RA and initiation of disease-modifying antirheumatic drug (DMARD) treatment of 42.9 months (SD 60.1). They have a low rate of interstitial lung disease (6.5%) and rheumatoid nodules (4.5%). Rheumatoid factor was positive in 65.5% of our patients. They have a mean Disease Activity Score (DAS) 28 score of 4.28 (SD 1.33). Only 12.5% of our patients are in remission with DAS 28 < 2.6 and 30.9% of our patients are having high disease activity with DAS 28 > 5.1. Despite the high usage of DMARDs in Sarawak (>80%), our patients have severe disease with high disease activity indices. This is most likely due to delay in diagnosis and initiating DMARDs in RA patients in Sarawak.

Standard of care for type 2 diabetic patients in a public hospital general medical clinic: report of a self-audit

We audited the standard of care provided to 200 consecutive type 2 diabetic patients attending our hospital general medical clinic. Data on diabetes related processes and outcome measures were collected. Annual testing rates (blood pressure 100%, fasting lipid profile 91.8%, HbA1c 69%) were higher compared to complications screening rates (Eye 69%, albuminuria 51%, foot 22.4%). Lifestyle intervention was lacking with BMI documented in 38.3% of patients and smoking history in 46%. Fifty percent and 41% of patients with HbA1c > 7.5% were referred to diabetes educator and dietitian respectively. For outcome measures, 26% of patients achieved HbA1c < or = 7%, 33% achieved BP < or = 130/80 while 56% achieved LDL < or = 2.6 mmol/L. Aspirin was prescribed in 78% and ACE inhibitor or angiotensin receptor blocker in 91.8% of patients. Lifestyle intervention and complication screening are the two major areas of deficiencies in the care of type 2 diabetic patients in our hospital general medical clinic.

Detection of the p53 response in zebrafish embryos using new monoclonal antibodies

The zebrafish has many advantages as a vertebrate model organism and has been extensively used in the studies of development. Its potential as a model in which to study tumour suppressor and oncogene function is now being realized. Whilst in situ hybridization of mRNA has been well developed in this species to study gene expression, antibody probes are in short supply. We have, therefore, generated a panel of anti-zebrafish p53 monoclonal antibodies and used these to study the p53 response in zebrafish embryos. By immunohistochemistry, we show that the exposure of zebrafish embryos to p53-activating agents such as R-roscovitine and gamma-irradiation results in the accumulation of p53 protein in the gut epithelium, liver and pancreas. A combination of R-roscovitine and gamma-irradiation results in massive p53 induction, not only in the pharyngeal arches, gut region and liver but also in brain tissues. Induction of apoptosis and expression of p53 response genes are seen in regions that correspond to sites of p53 protein accumulation. In contrast, although zebrafish tp53(M214K) mutant embryos showed a similar accumulation of p53 protein, a complete lack of a downstream p53-dependent response was observed. In this system the p53 gene is identified as a p53-responsive gene itself. Our results demonstrate that zebrafish p53 protein can readily be induced in embryos and detected using these new antibody tools, which will increase the usefulness of zebrafish as a model in compound-based screening for novel drugs in cancer research.

Intracranial aneurysms in Sarawak General Hospital over a 30-month period

This is a prospective study conducted from February 2000 to July 2002 in a single neurosurgeon neurosurgical service in the state of Sarawak, Malaysia. There were 66 cases of subarachnoid hemorrhage or intracranial aneurysm presenting to this hospital over the study period. Fifty cases had their aneurysms clipped. Eighty percent of our patients were operated within 48 h of presentation. Forty-four percent presented with poor WFNS grades of 4 and 5. We had a 20% operative mortality and 29% total management mortality. Twenty-nine (58%) of the operated cases had a favorable outcome with a mean follow-up of 32 weeks. Multiple aneurysms were less common. The diagnosis of aneuysmal subarachnoid hemorrhage and clipping of aneurysms have increased dramatically over the previous two and half years indicating an increased awareness of the diagnosis and treatment. This series supports the previously reported beliefs that the lower rate of aneurymal subarachnoid hemorrhage in developing countries is likely due to both underdiagnosis and undertreatment. Good results can be achieved in developing countries with early diagnosis and intensive management.

A rare case of subretinal cysticercosis

This is a case of a 25 year old lady whose eye had been infected by cysticercosis. This case highlighted that the inflammation was due to host immune response. She was treated with oral corticosteroid and the lesions regressed.

Proteinuria in diabetic patients in a primary health care setting in Sarawak

Diabetic nephropathy is now the number one cause of end stage renal failure in Malaysia. This places a huge burden on patients and the health care system especially in developing countries with limited health care resources, such as in Sarawak in East Malaysia. This study describes the prevalence of proteinuria/microalbuminuria in diabetic patients treated in Klinik Kesihatan Tanah Puteh. Early detection of proteinuria/microalbuminuria allows remedial measures to be taken to retard the progression of nephropathy. Forty-eight percent of the cases had proteinuria and microalbuminuria was found in 16%. Seventy-eight percent of cases with proteinuria were on treatment with angiotensin-converting-enzyme inhibitors or angiotensin-receptor blockers. Seventy-five percent of patients had hypertension but only 6% achieved the targeted BP of < 130/80 mmHg.

Mimetics of caloric restriction include agonists of lipid-activated nuclear receptors

The obesity epidemic in industrialized countries is associated with increases in cardiovascular disease (CVD) and certain types of cancer. In animal models, caloric restriction (CR) suppresses these diseases as well as chemical-induced tissue damage. These beneficial effects of CR overlap with those altered by agonists of nuclear receptors (NR) under control of the fasting-responsive transcriptional co-activator, peroxisome proliferator-activated co-activator 1alpha (PGC-1alpha). In a screen for compounds that mimic CR effects in the liver, we found statistically significant overlaps between the CR transcript profile in wild-type mice and the profiles altered by agonists of lipid-activated NR, including peroxisome proliferator-activated receptor alpha (PPARalpha), liver X receptor, and their obligate heterodimer partner, retinoid X receptor. The overlapping genes included those involved in CVD (lipid metabolism and inflammation) and cancer (cell fate). Based on this overlap, we hypothesized that some effects of CR are mediated by PPARalpha. As determined by transcript profiling, 19% of all gene expression changes in wild-type mice were dependent on PPARalpha, including Cyp4a10 and Cyp4a14, involved in fatty acid omega-oxidation, acute phase response genes, and epidermal growth factor receptor but not increases in PGC-1alpha. CR protected the livers of wild-type mice from damage induced by thioacetamide, a liver toxicant and hepatocarcinogen. CR protection was lost in PPARalpha-null mice due to inadequate tissue repair. These results demonstrate that PPARalpha mediates some of the effects of CR and indicate that a pharmacological approach to mimicking many of the beneficial effects of CR may be possible.

Glycaemic control of diabetic patients in an urban primary health care setting in Sarawak: the Tanah Puteh Health Centre experience

Achieving glycaemic goals in diabetics has always been a problem, especially in a developing country with inadequate facilities such as in Sarawak in Malaysia. There are no reported studies on the control of diabetes mellitus in a diabetic clinic in the primary health care setting in Sarawak. This paper describes the profile of 1031 patients treated in Klinik Kesihatan Tanah Puteh Health Centre. The mean age was 59 years, the mean BMI 27 kg/m2. There was a female preponderance and mainly type-2 diabetes. Mean HbA1c was 7.4%. Glycaemic control was optimal in 28% (HbA1c <6.5%), fair in 34% (HbA1c 6.5-7.5%) and poor in 38% (HbA1c >7.5%). Reasonable glycaemic control can be achieved in the primary health care setting in Sarawak.

Gene expression changes induced in mouse liver by di(2-ethylhexyl) phthalate

Increasing chemical use necessitates a better understanding of how pollutants, such as di(2-ethylhexyl) phthalate (DEHP), a peroxisome proliferator and a phthalate plasticizer, affect human health. To understand the effects of DEHP exposure, we utilized microarray technology to identify novel DEHP targets in livers of male C57BL/6 mice treated with 1.0% dietary DEHP for 13 weeks. We identified 51 DEHP-regulated genes; these genes are involved in, but not limited to, peroxisome proliferation, xenobiotic detoxification, oxidative stress response, immune function, steroid hormone metabolism, testis development, and pheromone transport. The reproductive toxicity mechanism of DEHP may be due to its effects on steroid hormone metabolism and sexual development. Confirmation of microarray results with Northern blots demonstrated that both low- and high-dose DEHP treatments altered the expression of genes associated with testis development and steroid hormone synthesis. Vanin-1, a regulator of testis development, was upregulated after exposure to 0.2 and 1.0% DEHP by 1.8- and 2.9-fold, respectively. Several genes involved in hormone metabolism were also regulated by DEHP. 11betaHSDI was downregulated 1.8- and 3.1-fold by 0.2 and 1.0% DEHP, respectively, while HSD3b5 was suppressed similarly by 0.2% DEHP, 1.5-fold, and more severely by 1.0% DEHP, 8.0-fold. Interestingly, food restriction had a similar effect to DEHP on several genes, including HSD3b5. In addition, steroidogenic gene cyp7B1 was downregulated while phospholipid transfer protein and cyp2B9 were induced. Genes peripherally associated with steroid hormones were also affected: ALDH3, GSTtheta2, and Id2. Collectively, our data validate the concern for DEHP as a reproductive developmental toxicant.

Effect of a peroxisome proliferator on 3 beta-hydroxysteroid dehydrogenase

To better understand the changes that occur following exposure to peroxisome proliferators, we utilized mRNA differential display and microarray to screen for peroxisome proliferator target genes apart from those involved in lipid metabolism in male C57B6 mice by using the ubiquitous plasticizer, di(2-ethylhexyl)phthalate (DEHP). One noted change was the dose-dependent suppression of the mouse hormone metabolizing 3 beta-hydroxysteroid dehydrogenase V (HSD3b5), which is specifically expressed in the male mouse liver. Northern analysis showed that HSD3b5 mRNA levels decreased dramatically upon one-day exposure to 2.0% dietary DEHP, and were nearly undetectable by one week of treatment. Food restriction also significantly suppressed HSD3b5 expression; however, in this case the suppression was delayed and to a lesser extent. Another mouse 3 beta-hydroxysteroid dehydrogenase, HSD3b4, predominantly expressed in kidneys, was also regulated by DEHP and food restriction. The sex-specific gene, HSD3b5, was affected more by DEHP and food restriction than the tissue-specific gene, HSD3b4.

Systemic considerations in the management of diabetic retinopathy

PURPOSE

To highlight the systemic factors which affect onset and/or progression of diabetic retinopathy (DR) and to emphasize the role and responsibilities of ophthalmologists and other eye care providers to ensure that appropriate systemic medical evaluation of the patient with diabetes is being pursued.

DESIGN

Literature review of publications relevant to diabetic retinopathy, blood glucose control, diabetes mellitus type, hypertension, renal disease, elevated serum lipids, exercise, pregnancy, anticoagulation, thrombolysis, smoking, anemia and antioxidant ingestion.

FINDINGS

Intensive blood glucose control and control of systemic hypertension reduce the risk of new onset DR and slow the progression of existing DR. Severe DR may be an indicator of renal disease while severe renal disease and its treatment can affect the progression of DR. Elevated serum lipids are associated with macular exudate and moderate visual loss. Certain types of excessive exercise in patients with advanced stages of retinopathy may aggravate vitreous hemorrhage. During pregnancy, DR should be monitored closely as transient progression of DR can occur. Therapeutic anticoagulation and thrombolysis are not contraindicated at any stage of DR. Anemia can result in progression of DR, smoking in general should be discouraged, and the role of antioxidant therapy requires further study.

CONCLUSIONS

Blindness from diabetic retinopathy is now largely preventable with timely detection and appropriate interventional therapy. Routine, repetitive, lifelong, expert clinical retinal examination is essential for the fundamental ophthalmic care of the patient with diabetes. However, diabetes mellitus is a systemic disease and thus optimal ophthalmic care must include diligent evaluation and treatment of concomitant systemic disorders that influence the development, progression and ultimate outcome of diabetic retinopathy. Optimization of these systemic considerations through an intensive, multi-disciplinary, healthcare team-based approach will maximize the ophthalmic and general health of these patients. Ophthalmologists and other eye care providers are critical members of this team with unique responsibilities to ensure that appropriate systemic medical evaluation is being pursued.

Composition and ultrastructure of size subclasses of normal human peripheral lymph lipoproteins: quantification of cholesterol uptake by HDL in tissue fluids

Peripheral lymph lipoproteins have been characterized in animals, but there is little information about their composition, and none about their ultrastructure, in normal humans. Therefore, we collected afferent leg lymph from 16 healthy males and quantified lipids and apolipoproteins in fractions separated by high performance-size exclusion chromatography. Apolipoprotein B (apoB) was found almost exclusively in low density lipoproteins. The distribution of apoA-I, particularly in lipoprotein A-I (LpA-I) without A-II particles, was shifted toward larger particles relative to plasma. The fractions containing these particles were also enriched in apoA-II, apoE, total cholesterol, and phospholipids and had greater unesterified cholesterol-to-cholesteryl ester ratios than their counterparts in plasma. Fractions containing smaller apoA-I particles were enriched in phospholipid. Most apoA-IV was lipid poor or lipid free. Most apoC-III coeluted with large apoA-I-containing particles. Electron microscopy showed that lymph contained discoidal particles not seen in plasma. These findings support other evidence that high density lipoproteins (HDL) undergo extensive remodeling in human tissue fluid. Total cholesterol concentration in lymph HDL was 30% greater (P < 0.05) than could be explained by the transendothelial transfer of HDL from plasma, providing direct confirmation that HDL acquire cholesterol in the extravascular compartment. Net transport rates of new HDL cholesterol in the cannulated vessels corresponded to a mean whole body reverse cholesterol transport rate via lymph of 0.89 mmol (344 mg)/day.

Nurses' experience of violence in Alberta and British Columbia hospitals

This study examined responses to a survey on violence in the workplace from a sample of 8,780 registered nurses practising in 210 hospitals in the Canadian provinces of Alberta and British Columbia. Findings relate to the frequency of violence against nurses, reported as the number of times they experienced a violent incident in the workplace. Nearly half (46%) of those surveyed had experienced 1 or more types of violence in the last 5 shifts worked. Frequency varied by type: emotional abuse 38%, threat of assault 19%, physical assault 18%, verbal sexual harassment 7.6%, sexual assault 0.6%. Further, 70% of those who had experienced violence indicated they had not reported it. Patients constituted the main source of all types of violence. The most prevalent type, emotional abuse, was further explored for its possible determinants. This was also the type of violence most evenly distributed among sources (patients, families, co-workers, physicians). Multiple regression modelling using the individual nurse as the unit of analysis showed the significant predictors of emotional abuse to be age, casual job status, quality of care, degree of hospital restructuring, type of unit, relationships among hospital staff, nurse-to-patient ratios, and violence-prevention measures; using the hospital as the unit of analysis the predictors were found to be quality of care, age, relationships with hospital staff, presence of violence-prevention measures, and province. These findings illustrate important differences in models that use the individual and the institution as the unit of analysis. Implications include targeting prevention strategies not only at the nurse but, perhaps more importantly, at the hospital. Overall, the findings suggest that health-care institutions are not always healthy workplaces and may increasingly be stressful and hazardous ones.

Vascular patterns in pterygium and conjunctival autografting: a pilot study using indocyanine green anterior segment angiography

AIMS

To characterise the vasculature of pterygium using indocyanine green (ICG) anterior segment angiography and to demonstrate the pattern of revascularisation following conjunctival autografting.

METHODS

ICG anterior segment angiography was performed on nine patients with pterygium. Angiography was repeated at 1-2 weeks and 2 months following conjunctival autografting in these patients.

RESULTS

Angiography showed a single feeder vessel originating from the anterior conjunctival circulation in six cases (66.7%). This vessel branched to form the radial vessels of the pterygium. Following conjunctival autografting, reperfusion of the vessels in the conjunctival autograft was demonstrable as early as 1 week postoperatively from the episcleral bed. At 2 months postoperatively, the graft appeared well perfused with mild leakage demonstrable at the edges of the graft.

CONCLUSIONS

A single feeder vessel from the anterior conjunctival circulation branches to form the radial vessels in pterygium. Reperfusion of conjunctival autografts occurs as early as 1 week postoperatively from the episcleral bed.

Indocyanine green anterior segment angiography for studying conjunctival vascular changes after trabeculectomy

BACKGROUND

The aim of the study was to evaluate the use of indocyanine green (ICG) for angiography of the anterior segment to characterize conjunctival and episcleral vasculature changes after trabeculectomy.

METHODS

This was a prospective evaluation of anterior segment ICG angiography in 10 eyes of 10 patients undergoing trabeculectomy for the first time. Trabeculectomy was performed with intraoperative sponge application of 5-fluorouracil (5 cases) or mitomycin C (5 cases). Anterior segment ICG angiography was performed prior to surgery, then at 2 weeks and 2 months after surgery.

RESULTS

With ICG, the anterior segment vessels were well delineated, including deep episcleral veins, which have not been clearly shown in previous angiographic techniques. Late phases of the angiogram could also be studied. The vascular alterations after trabeculectomy noted included oss of vascularity over the bleb area and vascular anastomoses along the perimeter of the avascular bleb.

CONCLUSIONS

Angiography using ICG has potential as an investigative tool to study the conjunctival and episcleral vasculature changes after trabeculectomy.

Importance of local tumour control in breast cancer

The overall importance of local tumour control in the management of breast cancer, specifically the influence of local control on survival, remains one of the fundamental questions for oncologists. This review addresses the issues surrounding local tumour control, including the evolution of the concept of disease spread, the rationale for local control, the results of studies of radiotherapy after breast-conserving surgery and after mastectomy, and an interpretation of the recent data on post-mastectomy radiotherapy.

Resistance to diet-induced hypercholesterolemia and gallstone formation in ACAT2-deficient mice

The importance of cholesterol ester synthesis by acyl CoA:cholesterol acyltransferase (ACAT) enzymes in intestinal and hepatic cholesterol metabolism has been unclear. We now demonstrate that ACAT2 is the major ACAT in mouse small intestine and liver, and suggest that ACAT2 deficiency has profound effects on cholesterol metabolism in mice fed a cholesterol-rich diet, including complete resistance to diet-induced hypercholesterolemia and cholesterol gallstone formation. The underlying mechanism involves the lack of cholesterol ester synthesis in the intestine and a resultant reduced capacity to absorb cholesterol. Our results indicate that ACAT2 has an important role in the response to dietary cholesterol, and suggest that ACAT2 inhibition may be a useful strategy for treating hypercholesterolemia or cholesterol gallstones.

Diabetic retinopathy

INTRODUCTION

To provide a review of the current standard of care in diabetic eye management.

METHODS

A non-systematic evidence-based review utilising available data and consensus statements on the subject matter.

RESULTS

Diabetes mellitus affects some 9.0% of Singaporeans, and more than 60% of patients with diabetes in this population remained undiagnosed. Diabetic retinopathy is an important complication among diabetic patients and adverse visual outcome associated with this condition can be reduced by more than 95% by taking measures including good glycaemic control, timely and appropriate laser therapy, and vitrectomy surgery when indicated. An important aspect of management is the accurate disease classification which is essential for prognostication, appropriate follow-up schedule, and timing of therapeutic intervention purposes.

CONCLUSION

Diabetic retinopathy will remain a significant problem if the current trend in diabetes among Singapore residents prevails. As the severe visual impairment associated with diabetic retinopathy can be largely prevented with appropriate and timely intervention, the major challenge to the health care providers today is the identification and education of patients with diabetes, and the enrollment of these patients in a life-long comprehensive ophthalmic management programme in order to minimise visual morbidity.

Accuracy of clinical estimates of intraocular pressure in Chinese eyes

PURPOSE

To investigate the validity of clinical estimates of intraocular pressure (IOP) in Chinese people.

DESIGN

Prospective, cross-sectional, hospital-based in vivo study.

PARTICIPANTS

Twenty-three ethnic Chinese adults (aged 35-82 years) undergoing routine phacoemulsification surgery were examined.

TESTING

"True" IOP was measured with a solid-state hemodynamic monitor through a cannula in the anterior chamber. IOP was set successively to 10, 20, and 30 mmHg in each subject, using a reservoir of balanced salt solution. Intraocular pressure was simultaneously estimated by use of a hand-held applanation tonometer (Perkin's) and a Tono-Pen. The association between ocular biometric variables and measurement error was examined.

MAIN OUTCOME MEASURES

The median of three readings at each IOP level was taken as the IOP estimate of each instrument. Measurement error was calculated as the mean difference (tonometer minus direct measurement).

RESULTS

The error for the hand-held applanation tonometer was -1.6, -4.3 and -5.7 at 10, 20, and 30 mmHg, respectively. For the Tono-Pen the measurement error was +0.4, -2.0, and -4.1 at 10, 20, and 30 mmHg, respectively. We could identify no association between measurement error and corneal thickness or curvature, anterior chamber depth, or axial length.

CONCLUSIONS

The applanation tonometer and Tono-Pen underestimate the true IOP in Chinese eyes. Error increases as true IOP increases. These tonometers do not give an accurate estimate of IOP in East Asians.

Role of vascular endothelial growth factor in diabetic vascular complications

BACKGROUND

Much of the morbidity and mortality associated with diabetes mellitus predominantly reflects its deleterious effects on microcirculation and macrocirculation. During the past few years, rapid advancement has been made in our understanding of the mechanisms and molecules involved in the pathogenesis of diabetic microvasculopathy. This is particularly true with regard to retinal vascular disease and the role of the angiogenesis- and vasopermeability-inducing molecule, vascular endothelial growth factor (VEGF).

METHODS

Biochemical studies in many relevant cell types have been performed. Effects of VEGF action and inhibition have been evaluated in animals. Interventions that block the biochemical pathways initiated by VEGF have been tested both in culture and in animals. Human clinical trials have begun.

RESULTS

VEGF induces vascular endothelial cell proliferation, migration and vasopermeability in many cells and tissues. In vivo, VEGF has been identified as a primary initiator of proliferative diabetic retinopathy, and as a potential mediator of nonproliferative retinopathy. In addition, VEGF has been implicated in the development of neuropathy and nephropathy in the patient with diabetes. In patients with diabetes and coronary artery or peripheral vascular disease, VEGF may induce development of cardiac and limb vascular collateralization, respectively. Many biochemical processes mediating these actions have now been elucidated.

CONCLUSIONS

VEGF appears to play a central role in mediating diabetic vasculopathy in many organs. Improved understanding of the molecular mechanisms underlying these processes has permitted development of novel therapeutic interventions, several of which are now in human clinical trials. These scientific advances and various implications for the future care of vasculopathy associated with diabetes will be discussed.

Combined effect of isoflurane and esmolol on sympathetic responses to tracheal intubation

BACKGROUND

Influences of isoflurane and esmolol on endotracheal intubation induced sympathetic changes could be different. The effect of isoflurane and its combination with esmolol on catecholamine, blood pressure and pulse during endotracheal intubation were investigated.

METHODS

Thirty patients were anesthetized with 3.0% isoflurane and tracheal intubation was carried out at the 5th min following the exposure to isoflurane. Half of them received intravenous saline and the other half received esmolol 2 mg/kg at the 4th min. Cardiovascular parameters were recorded and venous blood samples were taken for measurement of catecholamines every min.

RESULTS

One min after administration of isoflurane, there was increase of heart rate (P < 0.05), while at the same time the epinephrine level fell (P < 0.05) and norepinephrine level remained unaltered. Both catecholamines raised after intubation (P < 0.05). The sympathetic responses to and the beta-antagonistic effect of esmolol on intubation were not significantly changed in the presence of isoflurane.

CONCLUSIONS

Isoflurane increased heart rate while paradoxically decreased epinephrine. Norepinephrine was more specifically related to endotracheal intubation, for its serum level had little change before the event. Based on catecholamine findings, the mechanism of isoflurane effect on the sympathetic system is probably different from that of endotracheal intubation.

Endogenous bacterial endophthalmitis: an east Asian experience and a reappraisal of a severe ocular affliction

PURPOSE

To report 32 eyes of 27 patients with endogenous bacterial endophthalmitis seen over a 4 year period. Features and outcomes of this condition in the current series and the cases reported in the literature from 1986-1998 were reviewed.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

All patients with this condition seen at the three participating general hospitals were included.

INTERVENTION

A review of the systemic and ocular characteristics, therapeutic methods, and final outcomes in patients afflicted with this condition.

MAIN OUTCOME MEASURES

Features studied included patients' demographic characteristics, microbiology, source of infection, ocular features, therapeutic interventions, final visual and anatomic outcomes.

RESULTS

Nineteen (70%) of the 27 incriminating organisms in this case series were gram negative microbes, with Klebsiella pneumoniae infections alone being responsible in 16 (60%) cases. Hepatobiliary tract infection was the source of bacteremia in 13 (48%) patients. Only nine (28%) eyes obtained good final visual acuity (20/120 or better), and two eyes were enucleated/eviscerated. A literature review of 209 patients with endogenous endophthalmitis over a 12 year period showed a similar increase in the frequency of gram negative microbes as the responsible organism, especially among the East Asian population. Overall, 22% had bilateral involvement; two thirds of patients had predisposing factor(s) or underlying illness(es), and diabetes mellitus was present in 46%. Thirty-four percent of all eyes obtained counting finger or better final vision, and 16% had their eyes eviscerated or enucleated. Infections with virulent organisms (gram negative rods, Serratia, Bacillus) usually denoted a grave visual prognosis; however, a media that was not opaque on presentation was usually associated with a good prognosis.

CONCLUSION

Metastatic ocular infection is not uncommon despite the availability of modern antibiotic therapy. Among the East Asian population, the patient at highest risk is a diabetic patient with Klebsiella pneumoniae hepatobiliary infection. In contrast, in the Caucasian population, this condition occurs in predisposed patients with gram-positive bacteremia arising from endocarditis or skin/joint infections. The final visual outcome in patients with endogenous bacterial endophthalmitis in the recent 12 years has not differed significantly from five decades ago.

The relationship between lymphatic vessell invasion, tumor size, and pathologic nodal status: can we predict who can avoid a third field in the absence of axillary dissection?

PURPOSE

Tangential (2-field) radiation therapy to the breast and lower axilla is typically used in our institution for treating patients with early-stage breast cancer who have 0-3 positive axillary nodes, as determined by axillary dissection, whereas a third supraclavicular/axillary field is added for patients with 4 or more positive nodes. However, dissection may result in complications and added expense. We, therefore, assessed whether clinical or pathologic factors of the primary tumor could reliably predict, in the absence of an axillary dissection, which patients with clinically negative axillary nodes have such limited pathologic nodal involvement that they might be effectively treated with only tangential fields. This would eliminate both the complications of axillary dissection and the added complexity and potential morbidity of a supraclavicular/axillary field.

METHODS AND MATERIALS

In this study, 722 women with clinical Stage I or II unilateral invasive breast cancer of infiltrating ductal histology, with clinically negative axillary nodes, at least 6 lymph nodes recovered on axillary dissection, and central pathology review were treated with breast-conserving therapy from 1968 to 1987. Pathologic nodal status was assessed in relation to clinical T stage, the presence of lymphatic vessel invasion (LVI), age, histologic grade, and the location of the primary tumor.

RESULTS

LVI, T stage, and tumor location were each significantly correlated with nodal status on univariate analysis. Ninety-seven percent of LVI-negative patients had 0-3 positive axillary nodes compared to 87% of LVI-positive patients. There was no association between T stage and extent of axillary involvement within LVI-negative and LVI-positive subgroups. In a logistic regression model, only LVI remained a significant predictor of having 4 or more positive nodes, although tumor size was of borderline significance. The odds ratio for LVI (positive vs. negative) as a predictor of having 4 or more positive nodes was 3.9 (95% CI, 2.0-7.6).

CONCLUSION

For patients with clinical T1-2, N0, infiltrating ductal carcinomas, the presence of LVI is predictive of having 4 or more positive axillary nodes. Only 3% of patients with clinical T1-2, N0, LVI-negative breast cancers had 4 or more positive nodes on axillary dissection. Such patients may be reasonable candidates for treatment with tangential radiation fields in the absence of axillary dissection.

Nipah viral encephalitis or Japanese encephalitis? MR findings in a new zoonotic disease

BACKGROUND AND PURPOSE

An epidemic of suspected Japanese encephalitis occurred in Malaysia in 1998-1999 among pig farmers. In neighboring Singapore, an outbreak occurred among pig slaughterhouse workers. It was subsequently established that the causative agent in the outbreak was not the Japanese encephalitis virus but a previously unknown Hendra-like paramyxovirus named Nipah virus.

METHODS

The brain MR images of eight patients with Nipah virus infection were reviewed. All patients tested negative for acute Japanese encephalitis virus. Seven patients had contrast-enhanced studies and six had diffusion-weighted examinations.

RESULTS

All patients had multiple small bilateral foci of T2 prolongation within the subcortical and deep white matter. The periventricular region and corpus callosum were also involved. In addition to white matter disease, five patients had cortical lesions, three had brain stem involvement, and a single thalamic lesion was detected in one patient. All lesions were less than 1 cm in maximum diameter. In five patients, diffusion-weighted images showed increased signal. Four patients had leptomeningeal enhancement and four had enhancement of parenchymal lesions.

CONCLUSION

The brain MR findings in patients infected with the newly discovered Nipah paramyxovirus are different from those of patients with Japanese encephalitis. In a zoonotic epidemic, this striking difference in the appearance and distribution of lesions is useful in differentiating these diseases. Diffusion-weighted imaging was advantageous in increasing lesion conspicuity.

Corneal transmissibility of diode versus argon lasers and their photothermal effects on the cornea and iris

PURPOSE

Diode laser (810 nm) may possess theoretical advantages over the argon blue-green laser (488 nm) for iridotomy/iridoplasty in an eye with oedematous cornea, such as the acute angle-closure glaucoma (AACG) patient, because of better diode laser tissue penetration in opaque media. We assessed the transmissibility of diode and argon lasers through corneas of varying clarity and evaluated the histopathological features of cornea and iris burns produced by these lasers.

METHODS

The transmission of diode and argon lasers through human donor corneal buttons of three grades of clarity--clear, intermediate, and hazy--were compared. Corneal buttons of these varying levels of clarity were also treated with argon and diode lasers, with the beams deliberately focused onto the mid-stroma to assess their photothermal effects. Exposed pigmented irides from whole human eyes were treated directly with argon and diode lasers. The lasers were delivered via slit-lamp systems and the energy settings used were 1000 mW for argon and 980 mW for diode; spot sizes for both lasers were 100 microm, with exposure durations of 0.1 s. Light microscopy studies of these tissues were performed.

RESULTS

Transmissibility of diode laser in clear, intermediate, and hazy corneas were 89, 87 and 85% respectively and was significantly superior to argon laser (78, 73 and 70% respectively; P < 0.001, paired Student's t-test). Diode laser did not produce morphological changes in all three grades of corneas whereas argon-laser-treated hazy corneas showed photothermal damage. Both lasers produced deep iris burns, with the diode laser tending to produce deeper burns.

CONCLUSION

Our findings suggest that diode laser may be the ideal laser for iridotomy/iridoplasty in the AACG patient with hazy cornea.

Spontaneous suprachoroidal haemorrhage in a patient receiving low-molecular-weight heparin (fraxiparine) therapy

Spontaneous suprachoroidal bleeding is a rare event. Of the six previously reported cases, five had identifiable mechanisms for the development of choroidal bleeding in addition to concurrent systemic anticoagulation/thrombolytic therapy. We report a case of spontaneous suprachoroidal haemorrhage in a patient who received subcutaneous low-molecular-weight heparin therapy but without any identifiable ocular condition predisposing to choroidal bleeding.

Apolipoprotein B-related gene expression and ultrastructural characteristics of lipoprotein secretion in mouse yolk sac during embryonic development

In mice, the yolk sac appears to play a crucial role in nourishing the developing embryo, especially during embryonic days (E) 7;-10. Lipoprotein synthesis and secretion may be essential for this function: embryos lacking apolipoprotein (apo) B or microsomal triglyceride transfer protein (MTP), both of which participate in the assembly of triglyceride-rich lipoproteins, are apparently defective in their ability to export lipoproteins from yolk sac endoderm cells and die during mid-gestation. We therefore analyzed the embryonic expression of apoB, MTP, and alpha-tocopherol transfer protein (alpha-TTP), which have been associated with the assembly and secretion of apoB-containing lipoproteins in the adult liver, at different developmental time points. MTP expression or activity was found in the yolk sac and fetal liver, and low levels of activity were detected in E18.5 placentas. alpha-TTP mRNA and protein were detectable in the fetal liver, but not in the yolk sac or placenta. Ultrastructural analysis of yolk sac visceral endoderm cells demonstrated nascent VLDL within the luminal spaces of the rough endoplasmic reticulum and Golgi apparatus at E7.5 and E8.5. The particles were reduced in diameter at E13.5 and reduced in number at E18.5;-19. The data support the hypothesis that the yolk sac plays a vital role in providing lipids and lipid-soluble nutrients to embryos during the early phases (E7;-10) of mouse development. secretion in mouse yolk sac during embryonic development.

Survival advantage in Asian American end-stage renal disease patients

Survival advantage in Asian American end-stage renal disease patients.

BACKGROUND

An earlier study documented a lower mortality risk for end-stage renal disease (ESRD) patients in Japan compared with the United States. We compared the mortality of Caucasian (white) and Asian American dialysis patients in the United States to evaluate whether Asian ancestry was associated with lower mortality in the United States.

METHODS

The study sample from the U.S. Renal Data System census of ESRD patients treated in the United States included 84,192 white or Asian patients starting dialysis during May 1995 to April 1997, of whom 18,435 died by April 30, 1997. Patient characteristics were described by race. Relative mortality risks (RRs) for Asian Americans relative to whites were analyzed by Cox proportional hazards regression models adjusting for characteristics and comorbidities. Population death rates were derived from vital statistics for the United States and Japan by age and sex.

RESULTS

Adjusting for demographics, diabetes, comorbidities, and nutritional factors, the RR for Asian Americans was 0.75 (P = 0.0001). Race-specific background population death rates accounted for over half of the race-related mortality difference. For whites, mortality decreased as the body mass index (BMI) increased. For Asians, the relationship between BMI and survival was u-shaped. The ratio of Asian American/white dialysis death rates and the ratio of Asian American/white general population death rates both varied by age in a similar pattern. The population death rates of Asian American and Japanese were also similar.

CONCLUSION

Among dialysis patients, Asian Americans had a markedly lower adjusted RR than whites. The effect of BMI on survival differed by race. Compared with the respective general population, dialysis patients had the same relative increase in death rates for both races. The difference in death rates between the United States and Japan does not appear to be primarily treatment related, but rather is related to background death rates.

A rapid calcium precipitation method of recovering large amounts of highly pure hepatocyte rough endoplasmic reticulum

We sought a rapid and non-ultracentrifugal method of recovering large amounts of highly pure rough endoplasmic reticulum (RER) membranes from livers. By substantially modifying a 20-year-old calcium precipitation technique, we obtained a RER fraction from rat liver and established its high degree of purity by quantitating classic membrane markers for different subcellular organelles. This RER fraction is highly enriched in four known proteins (or enzyme activities) required for lipoprotein assembly: apolipoprotein B, microsomal triglyceride transfer protein, acyl CoA:diacylglycerol acyltransferase, and acyl CoA:cholesterol acyltransferase, when compared to two classical RER markers, RNA and glucose-6-phosphatase. From one 10-12 g rat liver, we recover ten to twelve RER pellets of 1.5-1.6 cm in diameter containing approximately 110-125 mg of total protein, about half of which is sodium carbonate-releasable. By electron microscopy, these large RER pellets from rat livers are homogeneously comprised largely of non-vesiculated short strips of ribosome-rich membranes. This novel technique for isolating RER membranes from liver may provide a useful tool for future studies on the assembly of apolipoprotein B-containing lipoproteins as well as for research focused on mechanisms of secretory and membrane protein translation, translocation, and folding.

Analysis of the role of microsomal triglyceride transfer protein in the liver of tissue-specific knockout mice

A deficiency in microsomal triglyceride transfer protein (MTP) causes the human lipoprotein deficiency syndrome abetalipoproteinemia. However, the role of MTP in the assembly and secretion of VLDL in the liver is not precisely understood. It is not clear, for instance, whether MTP is required to move the bulk of triglycerides into the lumen of the endoplasmic reticulum (ER) during the assembly of VLDL particles. To define MTP's role in hepatic lipoprotein assembly, we recently knocked out the mouse MTP gene (Mttp). Unfortunately, achieving our objective was thwarted by a lethal embryonic phenotype. In this study, we produced mice harboring a "floxed" Mttp allele and then used Cre-mediated recombination to generate liver-specific Mttp knockout mice. Inactivating the Mttp gene in the liver caused a striking reduction in VLDL triglycerides and large reductions in both VLDL/LDL and HDL cholesterol levels. The Mttp inactivation lowered apo B-100 levels in the plasma by >95% but reduced plasma apo B-48 levels by only approximately 20%. Histologic studies in liver-specific knockout mice revealed moderate hepatic steatosis. Ultrastructural studies of wild-type mouse livers revealed numerous VLDL-sized lipid-staining particles within membrane-bound compartments of the secretory pathway (ER and Golgi apparatus) and few cytosolic lipid droplets. In contrast, VLDL-sized lipid-staining particles were not observed in MTP-deficient hepatocytes, either in the ER or in the Golgi apparatus, and there were numerous cytosolic fat droplets. We conclude that MTP is essential for transferring the bulk of triglycerides into the lumen of the ER for VLDL assembly and is required for the secretion of apo B-100 from the liver.

Trabeculectomy survival with and without intra-operative 5-fluorouracil application in an Asian population

PURPOSE

To define and compare the trabeculectomy survival with regard to intra-ocular pressure (IOP) control without further surgery or anti-glaucoma medication n an Asian population.

METHODS

A retrospective review of two consecutive groups of patients who had trabeculectomy surgery in a university eye department setting. The first group of patients (group A) did not receive any adjunctive 5-fluorouracil (5-FU), while the second group (group B) had intra-operative sponge application of 5-FU. Only the first trabeculectomy of patients who had bilateral trabeculectomy and the first trabeculectomy performed in patients who had repeated surgery was analysed. Combined procedures were excluded. Survival analysis was performed using the Kaplan-Meier product limit method.

RESULTS

Eighty-nine patients (51 in group A and 38 in group B) were studied, with a mean follow up of 37.5 and 27.0 months, respectively (P = 0.014). There were no statistical differences in age, gender, mean pretreatment IOP, pre-operative medication, proportion of patients with previous ocular surgery, or proportion of primary compared with secondary glaucoma between the two groups. The probability of trabeculectomy survival (IOP < 22 mmHg without additional medication/surgery) at 12 and 36 months was 54.3 and 36.4%, respectively, in group A and 75.8 and 65.8%, respectively, in group B. The differences in survival were significant (P = 0.006, log rank test).

CONCLUSIONS

Our experience with trabeculectomy survival in the Asian population showed poorer success when compared with Caucasian populations reported by other investigators. The survival of trabeculectomy surgery was improved significantly with intra-operative 5-FU. There may be justification for advocating a more liberal use of intra-operative 5-FU in such a population.

Chylomicron-sized lipid particles are formed in the setting of apolipoprotein B deficiency

The mechanisms for packaging large quantities of neutral lipids into apolipoprotein (apo) B-containing lipoproteins (chylomicrons or VLDL) are incompletely understood. However, several lines of evidence have suggested that the addition of core lipids to apoB to form a lipoprotein particle within the endoplasmic reticulum (ER) may involve two steps: first, the addition of small amounts of core lipids to membrane-bound apoB, generating a lipid-poor, small apoB-containing particle, and second, the fusion of that particle with a larger, independently formed triglyceride-rich and apoB-free "lipid particle." We sought to test this two-step hypothesis of apoB core lipidation by using electron microscopy to compare chylomicron assembly in mice that are genetically deficient in the ability to synthesize apoB in the intestine to control mice. In 19-day gestational mice (fasting setting) that were deficient in intestinal apoB synthesis, chylomicron-sized lipid particles in the lumen of the enterocyte ER were even more abundant and were 2- to 3-fold larger than those in the enterocytes of normal control mice. However, there were fewer lipid-staining particles in the Golgi apparatus, and many fewer particles in the extracellular space, compared with normal control mice. In both types of newborn suckling mice, much larger lipid particles were assembled within the lumen of the ER. They were however, less abundant and rarely reached the Golgi apparatus in fatty enterocytes of intestines deficient in apoB synthesis. These observations provide in vivo evidence that chylomicron formation could involve the synthesis of apoB-free triglyceride-rich particles within the endoplasmic reticulum (ER) lumen, and that the transport of these lipid particles out of the ER to Golgi apparatus and interstitium is facilitated by the acquisition of apoB.

Knockout of the abetalipoproteinemia gene in mice: reduced lipoprotein secretion in heterozygotes and embryonic lethality in homozygotes

Abetalipoproteinemia, an inherited human disease characterized by a near-complete absence of the apolipoprotein (apo) B-containing lipoproteins in the plasma, is caused by mutations in the gene for microsomal triglyceride transfer protein (MTP). We used gene targeting to knock out the mouse MTP gene (Mttp). In heterozygous knockout mice (Mttp+/- ), the MTP mRNA, protein, and activity levels were reduced by 50%, in both liver and intestine. Compared with control mice (Mttp+/+), chow-fed Mttp+/- mice had reduced plasma levels of low-density lipoprotein cholesterol and had a 28% reduction in plasma apoB100 levels. On a high-fat diet, the Mttp+/- mice exhibited a marked reduction in total plasma cholesterol levels, compared with those in Mttp+/+ mice. Both the livers of adult Mttp+/- mice and the visceral endoderm of the yolk sacs from Mttp+/- embryos manifested an accumulation of cytosolic fat. All homozygous embryos (Mttp-/-) died during embryonic development. In the visceral endoderm of Mttp-/- yolk sacs, lipoprotein synthesis was virtually absent, and there was a marked accumulation of cytosolic fat droplets. In summary, half-normal MTP levels do not support normal levels of lipoprotein synthesis and secretion, and a complete deficiency of MTP causes lethal developmental abnormalities, perhaps because of an impaired capacity of the yolk sac to export lipids to the developing embryo.

Genes for apolipoprotein B and microsomal triglyceride transfer protein are expressed in the heart: evidence that the heart has the capacity to synthesize and secrete lipoproteins

BACKGROUND

Expression of both the apolipoprotein B (apoB) gene and the microsomal triglyceride transfer protein (MTP) gene is required for the assembly and secretion of triglyceride-rich lipoproteins in the liver and intestine. Both genes have been assumed to be silent in the heart.

METHODS AND RESULTS

Northern blot and RNase protection analyses showed that the apoB and MTP genes were expressed in the hearts of mice and humans. In situ hybridization studies revealed that the apoB mRNA was produced in cardiac myocytes. Electron microscopy of human cardiac myocytes revealed lipid-staining particles of relatively small diameter (approximately 250 A) within the Golgi apparatus.

CONCLUSIONS

These studies strongly suggest that the heart synthesizes and secretes apoB-containing lipoproteins.

Allosteric effectors of hemoglobin as modulators of chemotherapy and radiation therapy in vitro and in vivo

INTRODUCTION

A series of molecules designed to be allosteric effectors of hemoglobin were examined for their potential as radiation sensitizers in vitro and in vivo and for their potential as chemosensitizers in vivo as well as for their antimetastatic effect.

RESULTS

At a concentration of 100 microM for 1 h prior to, during and for 1.5 h after radiation exposure, the allosteric effectors decreased the shoulder of the radiation survival curve of normally oxygenated EMT-6 cells and increased the slope of the radiation survival curves of hypoxic EMT-6 cells resulting in dose-modifying factors of 1.8 to 2.1. In vivo the allosteric effectors had antitumor activity against the Lewis lung carcinoma and produced primarily additive tumor growth delay when administered along with fractionated radiation therapy. When administered on days 4 through 18 after tumor implantation, the allosteric effectors, especially JP-7, RSR-13 and RSR-4, were highly effective antimetastatic agents in animals bearing Lewis lung carcinoma. In cell culture, simultaneous exposure to the allosteric effectors (at 100 microM) effectively sensitized EMT-6 cells to the effects of 4-hydroperoxycyclophosphamide, thiotepa and carboplatin. The allosteric effectors were not very cytotoxic toward EMT-6 tumor cells from tumors treated in vivo with single doses of each molecule nor were these agents very cytotoxic toward bone marrow CFU-GM taken from the same animals.

CONCLUSIONS

It is likely that the allosteric effectors have a molecular target in addition to hemoglobin. Other possible targets include hydroxymethyl-glutaryl-CoA reductase or microsomal cytochrome b5.