Influence of training in the use and generation of evidence on episiotomy practice and perineal trauma

OBJECTIVE

To examine episiotomy practices before and after a multi-component intervention designed to support the use and generation of research evidence in maternal and neonatal health care.

METHODS

Set in 9 centers across 4 Southeast Asian countries, a retrospective survey was performed for 12 recommended pregnancy/childbirth practices and 13 outcomes of women in each center before and after intervention. Qualitative interviews were conducted to assess staff awareness and experience in evidence-based practice.

RESULTS

There were significant decreases in the rate of episiotomy, from 64.1% to 60.1% (risk difference [RD] -4.0; 95% confidence interval [CI], -5.8 to -2.2) for all women and from 92.2% to 80.7% (RD -11.5; 95% CI, -13.4 to -9.6) for nulliparous women. Severe trauma decreased from 3.9% to 1.9% (RD -2.0; 95% CI, -2.7 to -1.4) for all women and from 6.7% to 3.0% (RD -3.7; 95% CI, -4.9 to -2.5) for nulliparous women. The frequency of intact perineum increased from 12.4% to 15.6% (RD 3.2; 95% CI, 1.9-4.6) for all women and from 1.7% to 8.0% (RD 6.3; 95% CI, 5.0-7.5) for nulliparous women.

CONCLUSION

An intervention based on understanding and using the best available evidence can result in significant improvements in care and health outcomes.

Building capacity for evidence generation, synthesis and implementation to improve the care of mothers and babies in South East Asia: methods and design of the SEA-ORCHID Project using a logical framework approach

Background

Rates of maternal and perinatal mortality remain high in developing countries despite the existence of effective interventions. Efforts to strengthen evidence-based approaches to improve health in these settings are partly hindered by restricted access to the best available evidence, limited training in evidence-based practice and concerns about the relevance of existing evidence. South East Asia - Optimising Reproductive and Child Health in Developing Countries (SEA-ORCHID) was a five-year project that aimed to determine whether a multifaceted intervention designed to strengthen the capacity for research synthesis, evidence-based care and knowledge implementation improved clinical practice and led to better health outcomes for mothers and babies. This paper describes the development and design of the SEA-ORCHID intervention plan using a logical framework approach.

Methods

SEA-ORCHID used a before-and-after design to evaluate the impact of a multifaceted tailored intervention at nine sites across Thailand, Malaysia, Philippines and Indonesia, supported by three centres in Australia. We used a logical framework approach to systematically prepare and summarise the project plan in a clear and logical way. The development and design of the SEA-ORCHID project was based around the three components of a logical framework (problem analysis, project plan and evaluation strategy).

Results

The SEA-ORCHID logical framework defined the project's goal and purpose (To improve the health of mothers and babies in South East Asia and To improve clinical practice in reproductive health in South East Asia), and outlined a series of project objectives and activities designed to achieve these. The logical framework also established outcome and process measures appropriate to each level of the project plan, and guided project work in each of the participating countries and hospitals.

Conclusions

Development of a logical framework in the SEA-ORCHID project enabled a reasoned, logical approach to the project design that ensured the project activities would achieve the desired outcomes and that the evaluation plan would assess both the process and outcome of the project. The logical framework was also valuable over the course of the project to facilitate communication, assess progress and build a shared understanding of the project activities, purpose and goal.

Anticoagulant therapy for deep vein thrombosis (DVT) in pregnancy

BACKGROUND

Thromboembolic complications are much higher in pregnancy due to procoagulant changes. Heparin does not cross the placenta and the use of unfractionated heparin (UFH) is the current established practice in prophylaxis and treatment for thromboembolism in pregnancy.

OBJECTIVES

To compare the effectiveness of anticoagulant therapies for the treatment of deep vein thrombosis in pregnancy. The anticoagulant drugs included are UFH, low molecular weight heparin (LMWH) and warfarin.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2010) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials comparing any combination of warfarin, UFH, LMWH and placebo in pregnant women.

DATA COLLECTION AND ANALYSIS

We used methods described in the Cochrane Handbooks for Systemic Reviews of Interventions for assessing the eligibility of studies identified by the search strategy. A minimum of two review authors independently assessed each study.

MAIN RESULTS

We did not identify any eligible studies for inclusion in the review.We identified three potential studies; after assessing eligibility, we excluded all three as they did not meet the prespecified inclusion criteria. One study compared LMWH and UFH in pregnant women with previous thromboembolic events and, for most of these women, anticoagulants were used as thromboprophylaxis. There were only three women who had a thromboembolic event during the current pregnancy and it was unclear whether the anticoagulant was used as therapy or prophylaxis. We excluded one study because it included only women undergoing caesarean birth. The third study was not a randomised trial.

AUTHORS' CONCLUSIONS

There is no evidence from randomised controlled trials on the effectiveness of anticoagulation for deep vein thrombosis in pregnancy. Further studies are required.

Survey of knowledge and perception on the access to evidence-based practice and clinical practice change among maternal and infant health practitioners in South East Asia

Background

Evidence-based practice (EBP) can provide appropriate care for women and their babies; however implementation of EBP requires health professionals to have access to knowledge, the ability to interpret health care information and then strategies to apply care. The aim of this survey was to assess current knowledge of evidence-based practice, information seeking practices, perceptions and potential enablers and barriers to clinical practice change among maternal and infant health practitioners in South East Asia.

Methods

Questionnaires about IT access for health information and evidence-based practice were administered during August to December 2005 to health care professionals working at the nine hospitals participating in the South East Asia Optimising Reproductive and Child Health in Developing countries (SEA-ORCHID) project in Indonesia, Malaysia, Thailand and The Philippines.

Results

The survey was completed by 660 staff from six health professional groups. Overall, easy IT access for health care information was available to 46% of participants. However, over a fifth reported no IT access was available and over half of nurses and midwives never used IT health information. Evidence-based practice had been heard of by 58% but the majority did not understand the concept. The most frequent sites accessed were Google and PubMed. The Cochrane Library had been heard of by 47% of whom 51% had access although the majority did not use it or used it less than monthly. Only 27% had heard of the WHO Reproductive Health Library and 35% had been involved in a clinical practice change and were able to identify enablers and barriers to change. Only a third of participants had been actively involved in practice change with wide variation between the countries. Willingness to participate in professional development workshops on evidence-based practice was high.

Conclusion

This survey has identified the need to improve IT access to health care information and health professionals' knowledge of evidence-based health care to assist in employing evidence base practice effectively.

Emotional disorders among medical students in a Malaysian private medical school

INTRODUCTION

A study was done between December 2005 and January 2006 to determine the prevalence of emotional disorders among medical students in a private medical school in Ipoh, Perak, Malaysia and to determine the demographical characteristics, contributing factors and the key person consulted for emotional problems.

METHODS

Medical students in the private medical school completed the 12-item English version of the General Health Questionnaire (GHQ-12) and a demographical questionnaire. A cut-off point of 3/4 for the GHQ was used to determine negative and positive scores for emotional disorders.

RESULTS

Out of 292 medical students, 86.6 percent completed the questionnaires. A total of 117 students (46.2 percent) were found to have emotional disorders. There was no significant association of ethnicity, gender, age group, number of examinations sat, examination performances, past medical conditions and relationships with parents, siblings, course-mates and lecturers with positive GHQ scores. A significant association, however, was found between positive GHQ scores for emotional disorders and the year of study, pressure faced due to examinations, and not having a love relationship. 39 percent of the students stated friends as their main preference for consultation of any emotional problem.

CONCLUSION

The prevalence of emotional disorders among medical students was high. Further studies and diagnostic measures are recommended, including a more systematic screening and counselling programme by the medical school for early diagnosis and treatment to prevent complications.

Optimising reproductive and child health outcomes by building evidence-based research and practice in South East Asia (SEA-ORCHID): study protocol

Background

Disorders related to pregnancy and childbirth are a major health issue in South East Asia. They represent one of the biggest health risk differentials between the developed and developing world. Our broad research question is: Can the health of mothers and babies in Thailand, Indonesia, the Philippines and Malaysia be improved by increasing the local capacity for the synthesis of research, implementation of effective interventions, and identification of gaps in knowledge needing further research?

Methods/Design

The project is a before-after study which planned to benefit from and extend existing regional and international networks. Over five years the project was designed to comprise five phases; pre-study, pre-intervention, intervention, outcome assessment and reporting/dissemination. The study was proposed to be conducted across seven project nodes: four in South East Asia and three in Australia. Each South East Asian study node was planned to be established within an existing department of obstetrics and gynaecology or neonatology and was intended to form the project coordinating centre and focus for evidence-based practice activities within that region. Nine hospitals in South East Asia planned to participate, representing a range of clinical settings. The three project nodes in Australia were intended to provide project support.

The intervention was planned to consist of capacity-strengthening activities targeted at three groups: generators of evidence, users of evidence and teachers of evidence. The primary outcome was established as changes in adherence to recommended clinical practices from baseline to completion of the project and impact on health outcomes.

Discussion

The SEA-ORCHID project was intended to improve care during pregnancy and the perinatal period of mothers and their babies in South East Asia. The possible benefits extend beyond this however, as at the end of this project there is hoped to be an existing network of South East Asian researchers and health care providers with the capacity to generalise this model to other health priority areas. It is anticipated that this project facilitate ongoing development of evidence-based practice and policy in South East Asia through attracting long-term funding, expansion into other hospitals and community-based care and the establishment of nodes in other countries.

Changes in the process of care and outcome over a 10-year period in a neonatal nursery in a developing country

BACKGROUND

Over a 10-year period there was increasing involvement by clinicians in the generation and implementation of evidence-based practices in the neonatal intensive care unit (NICU). For two cohorts of very low birth weight (VLBW) babies admitted 10 years apart to a developing country, NICU were compared and changes occurring in process of care that might have contributed to any change in outcome were documented.

METHODS

Prospective data were collected on characteristics, management and complications of all VLBW infants admitted over the same 6-month period in 1993 and 2003 and examined for changes in evidence-based practices and outcome.

RESULTS

Compared to the first cohort of 69 babies, 60 babies in the second cohort were significantly more likely to have been inborn (p < 0.001), born by Caesarean section (p = 0.035), to have received antenatal corticosteroids (p < 0.001), to be intubated at birth (p < 0.001) and have a 5 min Apgar score above 6 (p = 0.034). They were also significantly lighter and of lower gestation (p = 0.005). They were significantly more likely to have received surfactant (p < 0.001), to have been ventilated and to have had double prong nasal continuous positive pressure either as a mode of ventilation or for weaning (p < 0.001). Hypothermia on admission was more common in the second cohort (p < 0.001). Survival increased from 62.3% to 81.6% (p = 0.015).

CONCLUSIONS

Although causality cannot be established, an increase in the use of evidence-based practices was associated with a significant improvement in outcomes. In spite of greater barriers to implementation there are evidence-based strategies that can be put into neonatal practice in developing countries.

Magnesium sulfate for persistent pulmonary hypertension of the newborn

BACKGROUND

Persistent pulmonary hypertension of the newborn (PPHN) occurs in approximately 1.9 per 1000 newborns and may be more frequent in developing countries. There is strong evidence for the use of inhaled nitric oxide (iNO) and extra corporeal membrane oxygenation (ECMO) in the treatment of PPHN. However, many developing countries do not have access or the technical expertise required for these expensive therapies. Magnesium sulfate is a potent vasodilator and hence has the potential to reduce the high pulmonary arterial pressures associated with PPHN. If magnesium sulfate were found to be effective in the treatment of PPHN, this could be a cost effective and potentially life-saving therapy.

OBJECTIVES

To evaluate the use of magnesium sulfate compared with placebo or standard ventilator management alone, sildenafil infusion, adenosine infusion, or inhaled nitric oxide on mortality or the use of backup iNO or ECMO in term and near-term newborns (> 34 weeks gestational age) with PPHN.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group (CNRG) was used. No language restrictions was applied. The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006) and MEDLINE (1966 to April 20, 2007) were searched for relevant randomized and quasi-randomized trials. In addition the reference lists of retrieved articles were reviewed and known experts were contacted to obtain unpublished data.

SELECTION CRITERIA

All randomised or quasi-random studies were eligible where one of the treatment groups received magnesium sulfate for PPHN.

DATA COLLECTION AND ANALYSIS

Standard methods of the Cochrane Collaboration and the CNRG were used, including independent assessment of trial quality and extraction of data by each author.

MAIN RESULTS

No eligible trials were found

AUTHORS' CONCLUSIONS

On the basis of the current lack of evidence, the use of magnesium sulphate cannot be recommended in the treatment of PPHN. Randomised controlled trials are recommended.

Helicobacter pylori, ethnicity, and the gastroesophageal reflux disease spectrum: a study from the East

BACKGROUND

Ethnic differences in gastroesophageal reflux disease (GERD) and its complications as well as racial variations in the prevalence of Helicobacter pylori infection are well documented. Nevertheless, the association between reflux disease, H. pylori, and race has not been adequately explored.

AIMS

We estimated the strength of the association between H. pylori, ethnicity, and the gastroesophageal reflux disease (GERD) spectrum, including Barrett's esophagus, in Asian patients presenting for endoscopy in a tertiary referral center.

METHODS

Prospectively, we studied 188 consecutive patients with GERD, short- and long-segment Barrett's esophagus, and controls. All patients underwent gastroscopy with gastric biopsies to assess H. pylori, gastritis, and atrophy. CagA status and H. pylori infection were determined by immunoblot assay.

RESULTS

The overall prevalence of H. pylori infection was 52.1% (of which 77.6% were cagA(+)) and was lowest in the long-segment Barrett's esophagus group (36.7%) (p = .048). When Barrett's esophagus was present, the length of abnormality was 44.8% shorter in the presence of H. pylori (p = .015). Indians had the highest prevalence of H. pylori (75%) and Malays the lowest (19.6%) (p < .001). In Indians, increased prevalence of H. pylori and cagA-positive strains was associated with reduced severity of GERD (p < .004 and p < .001, respectively), a trend not apparent in the other races. Corpus atrophy, which was almost exclusively associated with H. pylori, was highest in Indians as compared to the other races (p = .013).

CONCLUSIONS

Presence of H. pylori was associated with a reduced severity of GERD spectrum disease in Asians, especially Indians. H. pylori infection may protect against complicated reflux disease via induction of corpus atrophy.

Loss of human leucocyte antigen class I and gain of class II expression are early events in carcinogenesis: clues from a study of Barrett's oesophagus

BACKGROUND

Human leucocyte antigen (HLA) expression is altered in oesophageal carcinomas compared with normal tissue. It is unclear, however, whether this phenotype precedes malignant transformation or results as a consequence of it.

AIM

To investigate HLA class I and II expression in Barrett's oesophagus and normal squamous oesophageal tissue.

METHODS

Asian patients with Barrett's oesophagus (n = 64) and a control group (n = 60) with a normal oesophagus but without reflux symptoms were recruited using endoscopic and histopathological criteria. Tissue samples were stained with monoclonal antibodies specific for HLA-ABC, HLA-DR alpha chain or HLA-DP/DQ/DR, and scored semiquantitatively. The results of immunohistochemical staining were correlated with clinical and histopathological characteristics of patients.

RESULTS

Marked expression of HLA-ABC was observed in 50% of Barrett's oesophagus sections as compared with 68.3% of controls (p = 0.038). HLA-DR staining was seen in 51.6% of Barrett's oesophagus samples versus 11.7% of controls (p<0.001). Expression of HLA-DP/DQ/DR was evident in 73.4% of oesophageal intestinal metaplasia tissue as opposed to 18.3% of controls (p<0.001). Importantly, a total loss of HLA-ABC and a concomitant gain of HLA-DP/DQ/DR expression were seen in 37.5% of patients with Barrett's oesophagus but in none of the controls (p<0.001). Interestingly, this phenotype was associated positively with dysplasia (adjusted p, p* = 0.031) but negatively with non-steroidal anti-inflammatory drug use (p* = 0.004).

CONCLUSIONS

HLA class I expression is down regulated and class II expression is up regulated in Barrett's oesophagus. As these changes predate malignant transformation, altered major histocompatibility complex expression may be a key event in disease progression, possibly in facilitating evasion from immune surveillance.

Prenatal detection of birth defects in a Malaysian population: estimation of the influence of termination of pregnancy on birth prevalence in a developing country

We studied 253 women with a pregnancy complicated by a birth defect and 506 controls to determine the frequency and type of prenatal tests and the types of defects detected antenatally. Most women had at least one ultrasound examination, but the frequency of other screening tests was low. Only 38 (15%) of defects were detected antenatally (37 by ultrasound). Birth prevalence is unlikely to be affected by pregnancy termination.

A population-based study of birth defects in Malaysia

Birth defects are one of the leading causes of paediatric disability and mortality in developed and developing countries. Data on birth defects from population-based studies originating from developing countries are lacking. One of the objectives of this study was to determine the epidemiology of major birth defects in births during the perinatal period in Kinta district, Perak, Malaysia over a 14-month period, using a population-based birth defect register. There were 253 babies with major birth defects in 17,720 births, giving an incidence of 14.3/1000 births, a birth prevalence of 1 in 70. There were 80 babies with multiple birth defects and 173 with isolated birth defects. The exact syndromic diagnosis of the babies with multiple birth defects could not be identified in 18 (22.5%) babies. The main organ systems involved in the isolated birth defects were cardiovascular (13.8%), cleft lip and palate (11.9%), clubfeet (9.1%), central nervous system (CNS) (including neural tube defects) (7.9%), musculoskeletal (5.5%) and gastrointestinal systems (4.7%), and hydrops fetalis (4.3%). The babies with major birth defects were associated with lower birth weights, premature deliveries, higher Caesarean section rates, prolonged hospitalization and increased specialist care. Among the cohort of babies with major birth defects, the mortality rate was 25.2% during the perinatal period. Mothers with affected babies were associated with advanced maternal age, birth defects themselves or their relatives but not in their other offspring, and significantly higher rates of previous abortions. The consanguinity rate of 2.4% was twice that of the control population. It is concluded that a birth defects register is needed to monitor these developments and future interventional trials are needed to reduce birth defects in Malaysia.

Colonic diverticular disease in a multiracial Asian patient population has an ethnic predilection

BACKGROUND

Traditionally, diverticular disease of the colon has been attributed to ageing, low dietary fibre and a high intraluminal pressure. Recently, genetic and racial factors have also been implicated.

METHODS

Four-hundred and ten consecutive multiracial Asian patients undergoing colonoscopy for a variety of bowel symptoms in a private endoscopy unit were studied for differing frequencies (if any) in colonic diverticular disease and concomitant abnormalities.

RESULTS

Forty-one patients (10%) had diverticular disease. Diverticula were present in 22/147 Chinese (15%), 14/153 Indians (9%) and 5/110 Malays (4.5%). The mean age of patients with diverticular disease was 55 years as compared with 51.3 years in those without (P = 0.12) and there was no gender difference. Thirty-six patients (88%) had diverticula in the right colon only, four patients (10%) exclusively in the left hemicolon, and one patient (2%) had bilateral involvement. Using regression analysis, Chinese ethnicity [odds ratio (OR)=2.11; 95% confidence interval (CI), 1.09-4.09; P = 0.027), constipation (OR = 2.65; 95% CI, 1.23-5.42; P = 0.007) and colorectal adenomas (OR = 2.65; 95% CI, 1.08-6.46; P = 0.033) were independently associated with diverticular disease.

CONCLUSIONS

Colonic diverticular disease in a multiracial Asian patient population has an ethnic predilection and is predominantly right-sided.

Human leucocyte antigen determinants of susceptibility to Barrett's oesophagus in Asians--a preliminary study

BACKGROUND

Characteristic immune profiles have been demonstrated in gastro-oesophageal reflux disease. However, the genetic basis of gastro-oesophageal reflux disease remains unclear.

AIM

To investigate whether certain human leucocyte antigen genes are associated with Barrett's oesophagus.

METHODS

Asian patients of Malay, Chinese and Indian descent with Barrett's oesophagus (n = 59) and those without reflux symptoms and a normal oesophagus (n =60) were recruited prospectively using endoscopic and histopathological criteria. Human leucocyte antigen class I and II typing was performed using a polymerase chain reaction sequence-specific primers method.

RESULTS

The HLA-B7 allele was present in 17% (10 of 59) of patients with Barrett's oesophagus when compared with 0% (zero of 60) of controls [P = 0.0006, corrected P = 0.0171, OR = 25.67]. Subgroup analysis revealed that the HLA-B7 allele was confined almost exclusively to Indians with Barrett's oesophagus, 43% (nine of 21) vs. 0% (zero of 19) Indian controls (P = 0.0014, corrected P = 0.0406, OR = 29.64). No class II associations, protective human leucocyte antigens or extended haplotypes for disease susceptibility were identified.

CONCLUSIONS

Barrett's oesophagus in Asians, particularly Indians, is strongly positively associated with HLA-B7; reinforcing a genetic component to gastro-oesophageal reflux disease. A larger sample size and different ethnic populations should be genotyped to further confirm this association and identify possible additional risk factors in the human leucocyte antigen locus.

Risk of colorectal adenomas in a multiethnic Asian patient population: race does not matter

BACKGROUND

Ethnic differences have been reported for colorectal polyps and large bowel cancer; although the supporting data is weak and insufficient to draw firm conclusions.

AIM

We undertook this study to determine whether such racial disparity in colorectal adenomas exists in an ethnically mixed non-migrant population. The prevalence, histology and distribution of colonic polyps were documented as well as other known risk factors for colorectal malignancy.

METHODS

In this prospective cross-sectional study, 311 consecutive referred and self-referred multiracial patients attending for colonoscopy over a 41-month period in a private endoscopy center were recruited. The mean age of the study population was 51.8 +/- 14 years (range 16-91). The male to female ratio was 1.1 and an ethnic breakdown as follows: 87 Malays, 115 Chinese and 109 Indians.

RESULTS

Sixty-three adenomas were recorded in 36 patients: six Malays, 19 Chinese and 11 Indians. Of these adenomas, 59 were polypoid, three flat and one depressed. The majority of adenomas 42/63 (67%) were distal to the splenic flexure as were all (10/10) the Duke's A carcinomas and 6/8 (75%) of the advanced cancers. Patients with adenoma(s) compared with those without (controls) were significantly older (P = 0.005), more likely to have a family history of colorectal cancer (P = 0.005), and showed a trend towards significance for ethnic group (P = 0.09) on univariate analysis. Using logistic regression analysis, only family history (P = 0.05) and age > or = 50 years (P = 0.011) were found to be significantly associated with adenomas.

CONCLUSION

Risk factors for colonic adenoma(s) in our cohort of symptomatic multiethnic patients attending for colonoscopy do not seem to differ from those reported elsewhere and, in particular, race does not appear to be a factor.

Folic acid in the prevention of neural tube defect--a programme for Malaysia?

There is good evidence that folic acid is safe and efficacious for reducing neural tube defect (NTD). All women capable of becoming pregnant should take 400 microgram daily. This can be given in the form of a daily vitamin supplement, by food fortification, or by increasing natural dietary folates. Compulsory grain fortification has been shown to reduce NTD in a population but supplementation and dietary advice have not. Malaysia should work towards a programme of grain fortification and use alternative strategies to reach sections of the population that would not be covered but several research questions need to be answered before a programme could be implemented in Malaysia.

Continuous distending pressure for respiratory distress syndrome in preterm infants

BACKGROUND

Respiratory distress syndrome (RDS) is the single most important cause of morbidity and mortality in preterm infants (Greenough 1998, Bancalari 1992). Intermittent positive pressure ventilation (IPPV) with surfactant is the standard treatment for the condition. The major difficulty with IPPV is that it is invasive, resulting in airway and lung injury and contributing to the development of chronic lung disease.

OBJECTIVES

In spontaneously breathing preterm infants with RDS, to determine if continuous distending pressure (CDP) reduces the need for IPPV and associated morbidity without adverse effects.

SEARCH STRATEGY

The standard search strategy of the Neonatal Review group was used. This included searches of the Oxford Database of Perinatal Trials, Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2002), MEDLINE (1966-January 2002), and EMBASE (1980-January 2002), previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants, journal hand searching mainly in the English language.

SELECTION CRITERIA

All trials using random or quasi-random allocation of preterm infants with RDS were eligible. Interventions were continuous distending pressure including continuous positive airway pressure (CPAP) by mask, nasal prong, nasopharyngeal tube, or endotracheal tube, or continuous negative pressure (CNP) via a chamber enclosing the thorax and lower body, compared with standard care.

DATA COLLECTION AND ANALYSIS

Standard methods of the Cochrane Collaboration and its Neonatal Review Group were used, including independent assessment of trial quality and extraction of data by each author.

MAIN RESULTS

CDP is associated with a lower rate of failed treatment (death or use of assisted ventilation) [summary RR 0.70 (0.55, 0.88), RD -0.22 (-0.35, -0.09), NNT 5 (3, 11)], overall mortality [summary RR 0.52 (0.32, 0.87), RD -0.15 (-0.26, -0.04), NNT 7 (4, 25)], and mortality in infants with birthweights above 1500 g [summary RR 0.24 (0.07, 0.84), RD -0.281 (-0.483, -0.078), NNT 4 (2, 13)]. The use of CDP is associated with an increased rate of pneumothorax [summary RR 2.36 (1.25, 5.54), RD 0.14 (0.04, 0.23), NNH 7 (4, 24)].

REVIEWER'S CONCLUSIONS

In preterm infants with RDS the application of CDP either as CPAP or CNP is associated with benefits in terms of reduced respiratory failure and reduced mortality. CDP is associated with an increased rate of pneumothorax. The applicability of these results to current practice is difficult to assess, given the intensive care setting of the 1970s when four out of five of these trials were done. Where resources are limited, such as in developing countries, CPAP for RDS may have a clinical role. Further research is required to determine the best mode of administration and its role in modern intensive care settings

Early versus delayed initiation of continuous distending pressure for respiratory distress syndrome in preterm infants

BACKGROUND

The application of a continuous distending pressure (CDP) has been shown to have some benefits in the treatment of pre-term infants with respiratory distress syndrome (RDS). CDP has the potential to reduce lung damage, particularly if applied early before atelectasis has occurred. Early application of CDP may better conserve an infant's own surfactant stores and consequently be more effective than CDP applied later in the course of RDS.

OBJECTIVES

In pre-term infants with RDS to determine if early compared with delayed initiation of CDP results in lower mortality and reduced need for intermittent positive pressure ventilation.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Oxford Database of Perinatal Trials, Cochrane Controlled Trials Register (Issue 1, 2002), MEDLINE (1966-2001), previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants, journal hand searching mainly in the English language.

SELECTION CRITERIA

Trials among pre-term infants with respiratory distress syndrome spontaneously breathing at trial entry, which used random or quasi-random allocation to either early or delayed CDP.

DATA COLLECTION AND ANALYSIS

Standard methods of the Cochrane Collaboration and its Neonatal Review Group were used, including independent assessment of trial quality and extraction of data by two authors.

MAIN RESULTS

In six studies on a total of 165 infants, early CDP was associated with a significant reduction in subsequent use of intermittent positive pressure ventilation, typical RR 0.55, RD -0.16, NNT 6, but there was no evidence of effect on overall mortality. There was no evidence of effect on the rates of pneumothorax (five studies) or bronchopulmonary dysplasia (one study). Early CDP resulted in a reduction in duration of oxygen therapy in the single study reporting this outcome.

REVIEWER'S CONCLUSIONS

Early application of CDP has a clinical benefit in the treatment of RDS in that it reduces subsequent use of IPPV and thus may be useful in preventing the adverse effects of this treatment. However, many of the trials were done in the 1970s and 1980s and re-evaluation of the strategy of early CDP in the era of antenatal steroid use and early surfactant administration is indicated.

Use of the Griffiths Mental Scales in normal 2 year old Malaysian children

The Griffiths Scales for Mental Development were used to assess a group of 60 normal 2-year old Malaysian children (25 Indian, 23 Malay and 12 Chinese). The mean GQ was 104.2 (SD 9.3). This was significantly higher than the test mean of 100, p < 0.001. The mean score for Malaysian children was significantly higher on the locomotor, personal social, performance and practical reasoning subscales while they were significantly lower on the hand eye subscale and did not differ from the test mean on the hearing and speech subscale. There was a significant correlation between GQ and social class, r = -0.39, p < 0.05. Scores were lower than those currently obtained on British children, p < 0.001. Minor difficulties due to language and cultural factors arose over the interpretation of several items but with standardisation of these items the test is useful in Malaysian children.

Mortality from congenital abnormality in Malaysia 1991-1997: the effect of economic development on death due to congenital heart disease

An analysis was done of available data from the Department of Statistics Malaysia, on the type of congenital abnormality contributing to death, to determine whether progress in health care over recent years was associated with any decline in mortality from congenital abnormality. A significant decline in death due to congenital abnormality was observed between 1991 and 1996. This was attributable to a decline in deaths due to congenital heart disease occurring because of improvements in cardiac surgical services for infants. In 1997 death due to congenital heart disease increased significantly. This could be attributed to improvements in the diagnosis of congenital heart disease in the neonate.

Late onset infection in very low birth weight infants in Malaysian Level 3 neonatal nurseries. Malaysian Very Low Birth Weight Study Group

BACKGROUND

The purpose of this study was to examine the rate and mortality from late onset infection occurring in very low birth weight infants admitted to Malaysian nurseries.

METHODS

Data on all infants 1500 g or below admitted to the 20 participating Level 3 nurseries were analyzed for late onset infection (clinical infection and positive blood or cerebrospinal fluid culture occurring after 48 h of life).

RESULTS

The overall survival of the 962 study infants was 69%. The rate of late onset infection was 19.3%. The mortality in those with late onset infection was 30.8%. The most common infecting organism was Klebsiella pneumoniae, accounting for 38.3% of infections and 46.9% of deaths in infants with infection, followed by coagulase-negative staphylocci, 17.6 and 12.2%, respectively. On logistic regression analysis risk factors for late onset gram-negative compared with gram-positive infection were endotracheal intubation at birth and blood transfusion. Hypoglycemia was associated with gram-positive infection.

CONCLUSION

The late onset infection rate in Malaysian very low birth weight infants does not differ from that reported from developed countries, but the mortality is higher. This could be because of an excess of gram-negative infections.

Recurrent ocular herpes simplex keratitis following excimer laser photorefractive keratectomy in a rabbit model

PURPOSE

Reactivation of latent herpes simplex virus (HSV) by excimer laser photorefractive keratectomy(PRK) has been reported previously in the literature. This study evaluates the extent of such HSV reactivation and determines whether corneal de-epithelialization prior to PRK or the laser treatment itself induces this response.

METHODS

Twenty three normal 1.5-2.5 kg New Zealand white rabbits were infected on the surface of the cornea with HSV-1, strain RE. The animals were monitored until resolution and then divided into two treatment groups: 1) de-epithelialization alone, and 2) de-epithelialization plus laser. Animals were evaluated in a masked fashion by clinical examination and viral cultures twice a week through day 28.

RESULTS

The reactivation rate for group 1 (de-epithelization alone) was 0.0%, and for group 2 (PRK) was 67% by slit lamp biomicroscopy. Viral culture positivity rate matched these findings.

CONCLUSIONS

Excimer laser (193 nm) treatment can trigger viral shedding and reactivation of herpetic ocular disease in the latently infected rabbit. De-epithelialization alone is not sufficient to cause such viral reactivation or keratitis. Our findings suggest that patients with a history of herpetic keratitis undergoing PRK are at increased risk of HSV reactivation as a result of exposure to the excimer laser.

Mucin gene and antigen expression in biliopancreatic carcinogenesis

Mucins are high molecular weight glycoproteins which are heavily glycosylated with many carbohydrate side chains. In epithelial cancers such as biliopancreatic cancer, both quantitative and qualitative alterations in carbohydrate and polypeptide moieties of mucin glycoproteins occur. These changes in mucin glycoproteins are one of the most common phenotypic markers of biliopancreatic carcinogenesis and may play an important pathobiological role. The expression of some of the sialylated carbohydrate antigens appears to correlate with a poor prognosis and increased metastatic potential in biliopancreatic cancer. The increased exposure of peptide epitopes of mucin glycoproteins in biliopancreatic cancer appears to be due to either abnormal glycosylation and/or altered levels of mucin gene transcription. In addition, dysregulation of tissue specific mucin gene expression occurs in biliopancreatic cancer. This information is currently being exploited for further elucidation of the molecular mechanisms involved in carcinogenesis, tumor progression and metastasis, and the development of novel methods of diagnosis and therapy of biliopancreatic cancer.

Mucins in the diagnosis and therapy of pancreatic cancer

Mucins are large glycoproteins that form a protective layer along the lumens of the organs of the gastrointestinal and reproductive tracts. Frequently in tumors of the pancreas there are changes in the structure of mucin carbohydrates and/or levels of apomucin types. Originally mucins were of interest clinically because diagnostic tests could be based on their levels in circulation. More recently mucin directed monoclonal antibodies have been used to target tumors with cytotoxic agents. There is now a considerable literature on the development of mucin-based vaccines. Both monoclonal antibodies and vaccines could be powerful tools to specifically target tumor cells in distant metastases. Gene therapy based upon the MUC1 gene promoter is being investigated to target therapeutic genes to MUC1 expressing cells. The carbohydrates of mucins on the surface of tumor cells have been reported to inhibit cells of the immune system. These carbohydrates also act as ligands during the process of tumor cell metastasis. Another approach to therapy is to block interactions between the ligands and their receptors.

Forskolin increases the expression of the pancreatic tumor antigen, Nd2, and uptake of Nd2 antibody

Nd2 antibody recognizes an antigen that is tumor specific in pancreas. It has been used successfully in clinical radioimmunodetection studies to identify exocrine pancreatic tumors. In the present study we show that the uptake of radiolabeled Nd2 antibody by SW1990 pancreatic carcinoma cells was increased by the adenyl cyclase activator, forskolin. Dibutyryl cyclic AMP and forskolin were both effective in increasing the level of Nd2 antigen in SW1990 cells. Immunoprecipitation studies showed that the Nd2 epitope is associated with MUC1 mucin. Forskolin increased Nd2/MUC1 antigen in both a membrane fraction and a high buoyant density mucin-like fraction. Nd2 immunoreactivity was reduced by treatment of mucins with proteases and beta-mercaptoethanol. Immunohistochemical studies showed that periodate catalyzed beta-elimination greatly reduced Nd2 immunoreactivity. These results suggest that the Nd2 epitope is unusual in having characteristics of both a peptide and a carbohydrate, protease and conformation sensitivities and involvement of O-linked oligosaccharides. Nd2 antibody does not react with several known pancreatic cancer antigens. In summary, activation of the cyclic AMP pathway increased cellular uptake of Nd2 antibody and the cellular expression of the tumor-specific, mucin-associated Nd2 antigen. These results suggest a means of improving the effectiveness of monoclonal antibodies in targeting tumor antigens for the diagnosis and treatment of malignancy.

Long-term expression driven by herpes simplex virus type-1 amplicons may fail due to eventual degradation or extrusion of introduced transgenes

In gene therapy applications employing herpes simplex virus amplicon-based vectors, a prevailing problem is the down-regulation of transgene expression over time. We have applied a combined immunocytochemistry and fluorescent in situ hybridization method to determine whether down-regulation of transgene expression at the single-cell level correlates with loss of vector DNA from the host cell nucleus. Utilizing separate fluorescent labels (i.e., rhodamine, fluorescein, and 4',6'-diamidino-2-phenlindole), we were able to simultaneously detect transgenes, their products, and their locations relative to the nuclear compartment of a single cell. Detection of the reporter gene lacZ and its encoded protein beta-galactosidase (beta-gal) was accomplished in in vivo experiments of the dentate gyrus of rats. A time course study of the expression of the transgene post-stereotactic microinfusion up to 60 days was made. Expression reached maximal levels within 12-24 h after infection, and lacZ presence was reduced to less than 3% of its maximal levels within 36 h after infection. In comparing days 1 and 60 post-stereotactic microinfusion, only one-fifth of the original DNA was observed in the area of a 100-mm radius around the site of microinfusion at day 60. Moreover, by comparing the locations of the reporter gene in cells that expressed the encoded protein versus those that did not, we found that introduced transgenes were preferentially localized in the nuclear periphery of down-regulated host cells, compared to expressing host cells. These results suggest that nuclear compartmentalization may play a role in the down-regulation of our reporter gene by means of peripheralization, extrusion, and/or degradation.

Neuroprotective potential of a viral vector system induced by a neurological insult

Gene transfer into neurons via viral vectors for protection against acute necrotic insults has generated considerable interest. Most studies have used constitutive vector systems, limiting the ability to control transgene expression in a dose-dependent, time-dependent, or reversible manner. We have constructed defective herpes simplex virus vectors designed to be induced by necrotic neurological insults themselves. Such vectors contain a synthetic glucocorticoid-responsive promoter, taking advantage of the almost uniquely high levels of glucocorticoids-adrenal stress steroids-secreted in response to such insults. We observed dose-responsive and steroid-specific induction by endogenous and synthetic glucocorticoids in hippocampal cultures. Induction was likely to be rapid enough to allow transgenic manipulation of relatively early steps in the cascade of necrotic neuron death. The protective potential of such a vector was tested by inclusion of a neuroprotective transgene (the Glut-1 glucose transporter). Induction of this vector by glucocorticoids decreased glutamatergic excitotoxicity in culture. Finally, both exogenous glucocorticoids and excitotoxic seizures induced reporter gene expression driven from a glucocorticoid-responsive herpes simplex virus vector in the hippocampus in vivo.

Antibody-dependent cytotoxicity mediated by chimeric monoclonal antibody Nd2 and experimental immunotherapy for pancreatic cancer

In a previous study, mouse monoclonal antibody (MoAb) Nd2 (m-Nd2, mouse IgG1) labeled with (131)I exhibited efficacy in in vivo radioimmunotherapy against pancreatic cancer. In this study we prepared mouse / human chimeric antibody Nd2 (c-Nd2, human IgG1) for clinical use and examined whether c-Nd2 induced antibody-dependent cell-mediated cytotoxicity (ADCC). Cytotoxicity to pancreatic cancer (PC) cell lines, including Nd2 antigen-positive (SW1990, RWP-1, Capan-1) and Nd2 antigen-negative (Panc-1, MiaPaca-2, Capan-2) lines, was evaluated by mixed human leukocyte and tumor cell culture (MLTC) at an effector cell to target cell (E / T) ratio of 50 with or without Nd2. Cytotoxicities to SW1990 with no antibody, m-Nd2 and c-Nd2 (1 microg / ml) were 26.7%, 38.0% and 55%, respectively; to RWP-1, 28%, 41% and 70%; to Capan-1, 26%, 30% and 52%; to Panc-1, 24%, 28% and 30%; to MiaPaca-2, 18%, 20% and 27% and to Capan-2, 29. 7%, 35.0% and 40.6%. Cytotoxic capacity during MLTC with c-Nd2 was significantly higher than during MLTC with m-Nd2 or with no antibody. These findings indicated that cytotoxicity to Nd2-positive PC cells during MLTC is induced by ADCC. Intraperitoneal injection of c-Nd2 inhibited the tumor growth of SW1990 xenografted subcutaneously in nude mice and prolonged the survival of nude mice in which SW1990 tumor was transplanted orthotopically at the tail of the pancreas. These findings suggested that, because of its ability to induce ADCC, c-Nd2 may be clinically useful for the immunotherapeutic treatment of pancreatic cancer.

Forskolin and phorbol ester have opposite effects on the expression of mucin-associated sialyl-Lewis(a) in pancreatic cancer cells

The carbohydrate antigen sialyl-Lewis(a) is important to pancreatic tumour biology because the circulating antigen is used in serological tests for malignancy and because cell surface antigen is involved in tumour cell binding to the endothelial adhesion molecule, E-selectin, in extravasation. In this study, we examined the effects of the adenylyl cyclase activator, forskolin, and the diacylglycerol analogue, phorbol 12-myristate 13-acetate (PMA), on the expression and release of sialyl-Lewis(a) in human pancreatic cancer cells. Increases in the release of sialyl-Lewis(a) from SW1990 cells produced by forskolin and PMA were associated with increases in the activities of protein kinases A and C, respectively, and could be blocked by inhibitors specific for these enzymes. Immunoprecipitation experiments showed that sialyl-Lewis(a) was associated with MUC1 mucin. Forskolin also increased the cellular content of antigen and MUC1 mRNA. Actinomycin D and a protein kinase A inhibitor, H8, blocked these effects. In contrast, PMA reduced cellular antigen and MUC1 mRNA levels, although it produced a temporary increase in release of the antigen. The effects of PMA were blocked by the protein kinase C inhibitor, H7. PMA also reduced cell binding to the adhesion molecule E-selectin. In summary, PKA and PKC alter cell MUC1-associated sialyl-Lewis(a) in opposite directions. These changes may have clinical utility in the diagnosis of pancreatic cancer and the prevention of metastases.

Expression of MUC1 and MUC2 mucin antigens in intrahepatic bile duct tumors: its relationship with a new morphological classification of cholangiocarcinoma

Our previous immunohistochemical study on intrahepatic bile duct tumors showed that invasive cholangiocarcinoma (ICC) with a poor outcome expressed MUC1 mucin but was negative for MUC2 mucin, whereas bile duct cystadenocarcinoma (BDCC) with a favorable outcome was MUC1 negative and MUC2 positive. In the present study, ICC was further subdivided into 2 subtypes: intraductal growth type and/or periductal infiltrating type (ICC-IP) and mass forming type (ICC-M). The survival of patients with BDCC or ICC-IP is significantly better than that of patients with ICC-M. We examined these subtypes (ICC-IP and ICC-M) and BDCC for their expression of MUC1 mucins of different glycoforms. ICC-M showed significantly higher MUC1 expression rates (90%, 95%, and 85% positive rates as measured with the DF3, MY.1E12, and MUC1-Glycoprotein antibodies, respectively) than BDCC and ICC-IP (14% and 33%, 58% and 58%, and 0% and 50% positive respectively, as measured by the same antibodies). In contrast, BDCC (86% positive) and ICC-IP (67% positive) showed significantly higher MUC2 expression rates than ICC-M (25% positive) as measured with the anti-MRP antibody. Thus, the immunohistochemical staining pattern of ICC-IP resembled the pattern of BDCC more than they resembled ICC-M. In general, MUC1 expression is associated with poor patient outcome, irrespective of the glycosylation status. In particular, high expression of more sialylated forms of MUC1 mucins was correlated with poor survival. In contrast, expression of non-sialylated MUC2 mucin is a favorable prognostic indicator. These results suggest that ICC-IP is a different entity from ICC-M. This reclassification may have value in determining prognosis and treatment method.

Phorbol ester reduces phosphorylation of epidermal growth factor receptor in pancreatic cancer cells by activation of a tyrosine phosphatase

In this study we report that phorbol 12-myristate 13-acetate (PMA) transiently reduced the level of EGF receptor tyrosine phosphorylation in three pancreatic cancer cell lines (HPAC, SW1990, and UCVA-1) in response to EGF. The effect was maximal at 40-90 min. Pretreatment with the protein kinase C inhibitor GF 109203X reduced the PMA effect. Flow cytometry experiments showed that PMA produced only a slight reduction in the surface expression of EGF-R. The phosphotyrosine phosphatase inhibitor bpV(phen) returned phosphorylation to almost control levels. Moreover, homogenates of PMA treated pancreatic cells reduced the phosphorylation of activated receptor that was immunoprecipitated from A431 epidermoid cells. A combination of orthovanadate and NaF or bpV(phen) inhibited the effect of the homogenates. These results suggest that PMA activates a phosphotyrosine phosphatase activity that reduces the steady-state level of tyrosine phosphorylation of the receptor that is induced by EGF.

Preoperative clinical radioimmunodetection of pancreatic cancer by 111 In-labeled chimeric monoclonal antibody Nd2

The present study was carried out with the purpose of evaluating the clinical usefulness of radioimmunodetection (RAID) with 111In-labeled murine/human chimeric monoclonal antibody, Nd2 (c-Nd2) in patients with pancreatic cancer. Nineteen patients suspected to have pancreatic cancer were administered intravenously 74 MBq/2 mg 111In-labeled c-Nd2 in 100 ml of saline containing 2% albumin over 30 min. A scintigram was obtained on the 3rd day after infusion by using single photon emission computed tomography (SPECT) imaging. Of the 14 patients finally diagnosed as having pancreatic cancer on the basis of surgical specimens or progress of disease, specific focal uptake at the site of the tumor was detected in 12 (true positive cases), representing a sensitivity of 85.7% (12/14), and liver metastasis was found in one case with metastasis. Of the 5 patients diagnosed with tumor-forming pancreatitis (TFP), 4 patients demonstrated true negative imaging, but one patient whose tumor demonstrated interesting findings in histology and immunostaining, showed false positive imaging. Of patients investigated for human anti-chimeric antibody (HACA) response, none showed HACA response, and no allergic reaction was seen in any of the patients administered c-Nd2. These results suggest that RAID with 11In-labeled c-Nd2 is useful for differential preoperative diagnosis between invasive pancreatic cancer and TFP.

Biliopancreatic malignancy: future prospects for progress

Several key areas are targeted by novel therapies. Growth factors and their receptors are overexpressed in a high percentage of pancreatic tumors. These factors are critical to tumor cell growth and development. They also promote tumor growth by stimulating angiogenesis. Mutations in other molecules that regulate cell growth, such as the ras protein and the tumor suppressor p53, contribute to a state of continuously stimulated cell proliferation. Other types of molecules such as mucins are also altered or overexpressed in tumors. Mucins are immunosuppressive and are important in tumor cell metastasis. A number of promising new therapeutic strategies are now being tested. Ribozymes or antisense nucleic acids can prevent synthesis of growth factor receptors or ras protein. Monoclonal antibodies block interaction between receptor and its ligand. Newly developed drugs prevent tyrosine phosphorylation of growth factor receptors or farnesylation of ras protein. Gene therapy is another approach that is under investigation. Transduction or transfection of genes for wild-type tumor suppressors could correct defects in growth regulation. Vaccines developed against tumor antigens provide hope for the control of not only the primary tumor, but also of the metastatic lesions as well.

Neurodevelopmental outcome of very low birth weight babies admitted to a Malaysian nursery

OBJECTIVE

To examine the prevalence and pattern of neurodevelopmental handicap at 2 years of age in very low birth weight infants (VLBW) admitted in 1993 to a level 3 Malaysian nursery.

METHODS

All VLBW babies born in the hospital or referred for neonatal care during 1993 were enrolled prospectively in the study. At 2 years of age development was assessed using the Griffiths mental scales. Neurological, hearing and visual assessments were graded into five groups according to functional handicap. Control infants were randomly selected during attendance at a primary health care clinic.

RESULTS

One hundred and fifty VLBW infants were admitted and 82 (54.6%) survived to 2 years, of whom 77 (93.9%) were assessed. The mean General Quotient (GQ) on the Griffiths Scales was 94 (15.7) for the study group and 104 (8.3) for the 60 controls. For GQ, 21 (27.3%) of the study population were 1 or more SD below the mean (18 between 1 and 2 SD and 3 > 2 SD) compared with 1 (1.6%) of the controls who was 1-2 SD below the mean. Visual impairment occurred in 2 study infants and none of the controls. There was no hearing impairment in either group. Cerebral palsy occurred in 3 (1 mild and 2 moderate-severe) of the study group and none of the controls. Functionally 18 (23.3%) of the study group had mild handicap, 1 (1.3%) moderate, 2 (2.5%) severe, 2 (2.5%) multiply severe and 54 (70.2%) were normal.

CONCLUSION

Although survival was low, overall rates of functional handicap were similar to those reported in developed countries but the proportion with moderate or severe handicap was low.

Human immunodeficiency virus prevalence in women at delivery using unlinked anonymous testing of newborns in the Malaysian setting

OBJECTIVE

To determine the community prevalence of human immunodeficiency virus (HIV) in women at the time of delivery in a Malaysian setting.

METHODOLOGY

Cord blood samples from a pilot screening programme for congenital hypothyroidism in 1995 at Ipoh city and surrounding district hospitals were screened anonymously for HIV 1 and 2. HIV status was determined using chemiluminescent technology. Positive samples were retested using the Genelavia Mixt assay.

RESULTS

A total of 4927 samples were tested. The ethnic breakdown included 51.7% Malays, 18.9% Chinese, 14.3% Indian, 2.3% Others and 12.9% unknown. The geographical distribution of samples was 73.9% urban, 24.2% rural and 1.9% unknown. The seroprevalence of HIV positivity was 3.25 per 1000 deliveries (95% CI: 1.92-5.16). Seroprevalence was higher for samples from rural and Malay mothers.

CONCLUSION

The high seroprevalence in this study suggests that the spread of HIV is far wider than that anticipated by mandatory national reporting. It also supports antenatal screening and the use of antiretroviral therapy as an important strategy to reduce perinatal transmission.

Radioimmunotherapy of orthotopically transplanted pancreatic cancer with 131I-labeled chimeric monoclonal antibody Nd2

Recombinant mouse/human chimeric antibody Nd2 was previously reported to have the same specificity and reactivity against pancreatic cancer as murine Nd2 without HAMA production which induced serious problems in clinical application. We established orthotopic SW1990 transplanted mice to represent the progression of pancreatic cancer. We examined anti-tumor effect of 131I-labeled chimeric Nd2 in an orthotopic transplant model. 131I-labeled chimeric Nd2 inhibited the growth of orthotopically transplanted tumors and extended the survival time of the mice. These results suggest that 131I-labeled chimeric Nd2 has high clinical applicability in the therapy of pancreatic cancer.

Switching transient analysis of a metal/ferroelectric/semiconductor switch diode with high speed response to infrared light

A thin PbTiO(3)-n-p(+) silicon switch diode has been developed, in which the switching voltage (the turned-on voltage) changes in proportion to the infrared light power. The diode has a rapid response time of 0.65 mus compared with other conventional infrared sensors. It is attributed to the rapid switching device structure and the smaller pyroelectric layer thickness, 50 nm. In this paper, we have analyzed the rapid switching transient response by using heat conduction and switching theory successfully. The experimental results are in agreement with the theoretical analysis.

MUC3 human intestinal mucin. Analysis of gene structure, the carboxyl terminus, and a novel upstream repetitive region

MUC3 is a large mucin glycoprotein expressed by the human intestine and gall bladder. In this manuscript, we present details of the deduced protein structure of MUC3. The MUC3 carboxyl-terminal domain is 617 residues in length, including 511 residues of a non-repetitive mucin-like domain (27% Thr, 22% Ser, and 11% Pro) and a 106-residue Cys-rich domain with homology to the epidermal growth factor (EGF) -like structural motifs found in many proteins. The region of MUC3 located upstream of the previously described 51-base pair (bp) tandem repeats, which encode a major Ser and Thr-rich domain, consists of a second type of repetitive structure with an imperfect periodicity of approximately 1125 bp. This domain is also mucin-like and appears to be considerably larger than 2000 residues (6000 bp). The MUC3 gene itself is large and complex. Using pulse field gel electrophoresis and blot analysis, the smallest fragment found that contained all human genomic DNA hybridizing to the 51-bp tandem repeat probe was 200 kilobases with restriction enzyme SwaI. Both PvuII and PstI produced two sets of hybridizing fragments that were hypervariable within the human population with a pattern suggestive of both a variation in the number of tandem repeats (VNTR) and sequence polymorphism. These fragments varied independently of each other, but no genetic recombination was detected in a study of 40 human families. Thus, the MUC3 gene encodes a very large glycoprotein with a structure very different from that of any mucin currently described.

Expression of mucin-associated tumor antigens is altered by cell density

Mucin-associated sialylated Lewis antigens are implicated in tumor cell metastasis and are used in several tests for pancreatic cancer. Despite their clinical importance, little is known about the structures of the oligosaccharides of pancreatic cancer mucins or about the regulation of their synthesis or of the synthesis of their protein cores. In this study, we examined the effects of culture at high cell density on the expression of these antigens in the SW1990 human pancreatic cancer cell line. Mucins from cells that were 2.5 weeks post-confluent had increased expression of sialyl-Lewis(a) and Lewis(x) antigens but reduced expression of the DU-PAN-2 antigen (NeuAc alpha2,3Galbeta1,3GlcNAc-Gal-R) when compared to mucins from 1 day post-confluent cells. Sialyl-Lewis antigens differ from the DU-PAN-2 antigen by the presence of an additional fucose. Mucins from 2.5-week cells also had increased binding to lectins specific for fucose, such as AAL and UEAI, with no apparent change in the binding of lectins specific for sialic acids. Metabolically radiolabeled O-linked oligosaccharides with sialyl-Lewis(a) antigenic reactivity eluted from Bio-Gel P-10 in the region of sialylated and sulfated oligosaccharides. Oligosaccharides eluted from QAE-Sephadex (2 mM Tris base) in a pattern suggesting the presence of 1, 2 and 3 or more negative charges per oligosaccharide. Even after desialylation and desulfation, oligosaccharides eluted from Bio-Gel P-10 with apparent molecular sizes greater than glucose oligomers of 12 units. Culture of SW 1990 cells at high density also increased the steady-state levels of mRNA for mucins MUC1, 2, 4, 5 and 6. In summary, after prolonged culture at high cell density, SW1990 cells have qualitative changes in their oligosaccharides that may be due to up-regulation of fucosyltransferases.

Radioimmunodetection with 111In-labeled monoclonal antibody Nd2 in patients with pancreatic cancer

This report summarizes results from an initial clinical evaluation of radioimmunodetection (RAID) in patients with pancreatic cancer using murine monoclonal antibody Nd2, directed against mucins from pancreatic cancer. Nd2 (2 mg) was labeled with 111In (2 mCi) and injected into 19 patients suspected of having pancreatic cancer. Planar scintigrams were taken 3 days post-infusion. As for final diagnoses after surgery, 14 cases were pancreatic cancer, and one case each was chronic pancreatitis, neurilemmoma, islet cell carcinoma, cholangioma, and apparent absence of suspected recurrent lesion of pancreatic cancer. Of 14 patients with pancreatic cancer, RAID was positive in 10 cases (71.4%). Cases other than pancreatic cancer were all negative, so the specificity was 100%. These results demonstrate that RAID using 111In-Nd2 can be useful in differentiating exocrine pancreatic cancer from benign conditions and other types of carcinomas in the pancreatoduodenal regions.