Correlation between early postnatal body weight changes and lung ultrasound scores as predictors of bronchopulmonary dysplasia in preterm infants: A secondary analysis of a prospective study

Recent research links early weight changes (EWC) with bronchopulmonary dysplasia (BPD) in preterm neonates, while lung ultrasound score (LUS) has shown promise in predicting BPD. We aimed to explore the correlation between LUS and EWC as markers of extravascular lung edema and to investigate the correlation between LUS and EWC in preterm infants with respiratory distress syndrome regarding future BPD development. This secondary analysis of a prospective study involved infants ≤ 28 weeks gestation. Enrolled infants underwent lung ultrasound assessment on postnatal days 3, 7 and 14, measuring LUS. EWC was computed on the same time points. Infants were classified as either having BPD or not. Descriptive statistics, correlation coefficient, and area under the receiver operating characteristic (AUROC) curve analysis were utilized. Of 132 infants, 70 (53%) had BPD. Univariate analysis revealed statistically significant differences in LUS and EWC at days 3, 7, and 14 between BPD and no-BPD groups (p < 0.001). A statistically significant but weak positive correlation existed between LUS and EWC (r0.37, r0.29, r0.24, and p < 0.01) at postnatal days 3, 7, and 14, respectively. AUROC analysis indicated LUS having superior predictive capacity for the need for invasive mechanical ventilation at day 14 as well as the later BPD development compared to EWC (p < 0.0001).

CONCLUSION

In a cohort of extreme preterm infants, our study revealed a positive yet weak correlation between LUS and EWC, suggesting that EWC was not the major contributing to the evolving chronic lung disease.

WHAT IS KNOWN

• Recent evidence links Early Weight-Changes with bronchopulmonary dysplasia in preterm neonates. • Lung ultrasound score has shown promise in early prediction of the subsequent development of bronchopulmonary dysplasia in preterm infants. No studies have examined the correlation between Early Weight-Changes and Lung ultrasound score in preterm infants during first 2 weeks after birth.

WHAT IS NEW

• Our study demonstrated a positive and statistically significant correlation between early LUS and EWC, indicating their potential role as early predictors for the subsequent development of BPD in extreme preterm infants. • The weak correlation between the two parameters may stem from the possible restricted influence of EWC, given that it may not be the primary factor contributing to the evolving chronic lung disease.

Sex-Based Differences in the Sonographic Characterization of Diaphragm Thickness in Preterm Infants With Bronchopulmonary Dysplasia at Term Corrected Age: A Secondary Analysis of a Prospective Study

OBJECTIVE

To determine the sex-specific diaphragm thickness in infants with bronchopulmonary dysplasia (BPD) as well as in healthy term and near-term infants.

METHODS

We performed a secondary analysis of an observational study to compare the sonographic diaphragm thickness at end expiration (DTexp ) in female and male infants. The study included infants with BPD and healthy near-term and term infants. To account for differences in anthropometric measurements, we calculated the DTexp as a ratio of body surface area (BSA). Statistical analysis was performed using R statistical software.

RESULTS

Of the 111 infants included, 54 (48.6%) were female. There were no significant differences in mean (SD) birth gestation [26.2 (2.1) vs 26.3 (2.1) weeks] and mean study age [38.0 (2.0) vs 37.4 (1.1) weeks] of male vs female infants with BPD. The mean (SD) DTexp [1.5 (0.4) mm vs 1.2 (0.3) mm, P = .02] and DTexp /BSA [8.3 (2.3) mm/m2 vs 6.7 (1.6) mm/m2 , P < .01] were significantly thicker in female than male infants with BPD. In contrast, there were no significant differences in DTexp between sexes [1.5 (0.4) mm vs 1.5 (0.3) mm, P = .89] within the healthy control group. Moreover, there were no differences in inspiratory diaphragm thickness, diaphragm thickness fraction, or excursion between males and females in the BPD or healthy groups.

CONCLUSIONS

Male infants with BPD exhibit thinner diaphragm thickness compared with female infants. Its implication on higher rates of BPD in preterm males is unclear, but this finding highlights the need for further investigation.

Diaphragmatic Thickness and Excursion in Preterm Infants With Bronchopulmonary Dysplasia Compared With Term or Near Term Infants: A Prospective Observational Study

BACKGROUND

Diaphragmatic atrophy associated with mechanical ventilation is reported in pediatric and adult patients, but a similar association has not been described in preterm infants with bronchopulmonary dysplasia (BPD).

RESEARCH QUESTION

Does BPD impact the diaphragm thickness (DT) and diaphragm excursion (DE) in infants born before 32 weeks' gestation compared with healthy late preterm or term infants?

STUDY DESIGN AND METHODS

In this prospective observational case-control study, DT at end of expiration (DT_exp), DT at end of inspiration (DT_ins), DT fraction (DTF), and DE (DE) were assessed using bedside ultrasound. Two groups were compared: infants with BPD (patients) and healthy, postmenstrual age-matched infants (control participants). To account for variations in body size between groups, diaphragmatic measurements were expressed as a ratio of body surface area (BSA). Statistical analyses were conducted using SAS software version 9.4 (SAS Institute, Inc.).

RESULTS

We enrolled 111 infants, including 56 preterm infants with BPD (mean ± SD study age, 37.7 ± 1.7 weeks) and 55 healthy control participants (mean ± SD study age, 38.1 ± 1.5 weeks). DT_exp and DT_exp to BSA ratio were significantly lower in the BPD group compared with the healthy control group (mean ± SD, 1.3 ± 0.4 mm vs 1.5 ± 0.4 mm [P = .01] and 7.1 ± 1.4 mm/m² vs 7.8 ± 1.8 mm/m² [P = .03]). DTF and DE were significantly higher in the BPD group vs the healthy control group (mean ± SD, 61.8 ± 26.0 vs 43.3 ± 19.7 [P < .01] and 6.0 ± 1.7 mm vs 4.4 ± 1.6 mm [P < .01], respectively).

INTERPRETATION

In infants with BPD, DT_exp was significantly lower, whereas DTF and DE were significantly higher, compared with healthy, age-matched control participants. Future studies are required and should focus on describing the evolution of diaphragmatic dimensions in preterm infants with and without BPD.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT04941963; URL: www.

CLINICALTRIALS

gov.

High incidence of Plasmodium knowlesi malaria compared to other human malaria species in several hospitals in Malaysia

Through the regional control programme, Malaysia has been successfully reducing the incidence of Plasmodium falciparum and Plasmodium vivax infections. However, the incidence of zoonotic malaria Plasmodium knowlesi infection is increasing and now has been the major cause of malaria in Malaysia especially Malaysian Borneo. The emergence of knowlesi infection has threatened the malaria elimination programme which the government aims to reduce the overall malaria infections by 2020. Unlike other benign human Plasmodium spp., P. knowlesi can cause fatal infections. The aim of this study was to determine the incidence and distribution of five human malaria parasites including P. knowlesi in Peninsular Malaysia and Malaysian Borneo. A total of 112 blood samples were collected from seven states and district hospitals in Peninsular Malaysia and Malaysian Borneo from year 2015 to 2016. The samples were examined by microscopy and further confirmed by nested PCR assay targeting 18S rRNA gene of Plasmodium spp. Following the nested PCR assays, a total of 54 (48.2%) samples were positive for P. knowlesi infections, 12 (10.7%) cases were positive for P. vivax infections, followed by 7 (6.3%) cases of P. falciparum and 4 (3.5%) cases of P. malariae. There were 3 cases (2.7%) of mixed infections (P. knowlesi/P. vivax). However, no cases were identified as P. ovale. A total of 32 (28.6%) cases were found as negative infections. LoopMediated Isothermal Amplification Assay (LAMP) was performed to confirm inconclusive results produced by microscopy and nested PCR. P. knowlesi showed the highest prevalence in Sarawak (n= 30), Sabah (n=13), Pulau Pinang (n=5) and Pahang (n=6). PCR and LAMP was not able to detect a large number of microscopy positive samples due to DNA degradation during storage and shipping. Among all the states involved in this study, the highest prevalence of P. knowlesi infection was found in Sabah and Sarawak.

DSPECT-specific normal limits for LV measurements: a new approach to derivation

Funding Acknowledgements

Type of funding sources: None.

Background

Differences in spatial resolution and image filtering between the solid-state DSPECT and traditional Anger SPECT (A-SPECT) cameras are likely to result in differences in LV measurements. However, DSPECT- specific normal values have not been systematically derived. We used healthy organ-donor subjects from our high-volume solid organ transplant center for derivation of normal values.

Purpose

To report DSPECT-specific LV measurements normal limits derived from a unique cohort of donor subjects.

Methods

Subjects were 92 consecutive kidney or liver donors who underwent single day rest (5 mCi)- stress (15mCi) Tc-99m sestamibi gated SPECT myocardial perfusion imaging (MPI) on the DSPECT for pre-operative evaluation. Exclusion criteria included any cardiac disease or medications. LV measurements were made on the post-stress supine stress images using QGS®.

Results

Of 92 subjects (mean age 54.4 ± 15.0 and 39% men), mean EF for women and men were 77.2 ± 14.1% and 70.0 ± 14.7%, respectively. Mean end-diastolic volume for women and men were 67.0 ± 32.2 ml and 99.6 ± 51.6 ml (indexed 38.3 ± 17.2 ml/m2 and 48.1 ± 25.9 ml/m2), respectively. Mean LV wall volume for women and men were 95.9 ± 26.0 ml and 112.0 ± 48.8 ml (indexed 55.0 ± 13.8 ml/m2 and 54.1 ± 24.6 ml/m2), respectively.

Conclusion

We report DSPECT-specific LV measurements from normal subjects from which limits of normality can be derived for clinic use. Organ-donors who undergo pre-operative MPI are a suitable cohort for the derivation of normal values.

GSDME: A Potential Ally in Cancer Detection and Treatment

Gasdermin E (GSDME) is an executioner of caspase-3 mediated regulated pyroptosis, and as such plays an important role in several cancers. Recent findings highlighted the potential of GSDME as a biomarker that can be implemented in cancer diagnosis, monitoring, and therapy.

Knowledge of heat waves and practice of protective measures against it in a rural West African

Background

Heat wave has a direct linkage to global climate change and is associated with increased morbidity and mortality. Between March and May 2019, Nigeria experienced severe heat waves. Understanding heat waves provides an opportunity for individuals to proactively take measures to prevent its negative health impacts. However, illiteracy levels in rural Sub-Saharan Africa are higher than in urban areas.This study was therefore conducted to assess knowledge of heat waves and practice of protective measures against it in an affected rural community of Nigeria.

Methods

A cross-sectional, community based descriptive study conducted among household heads in Nasarawan Buhari, a rural agrarian community in Nigeria. An interviewer-administered questionnaire was used to collect data from 104 household heads, selected using systematic random sampling technique. Data was analyzed using SPSS (version 20).

Results

A majority of the respondents were males (79.8%) and most of them (89.4%) had poor knowledge of heat waves. Farming occupation was significantly associated with knowledge of heat waves (P = 0.025). Awareness of measures needed to protect against the negative health impacts of heat waves was also poor. Hence fluid intake and cold showers were the only protective measures used by majority of respondents to reduce effect of the extreme heat.

Conclusions

Both knowledge of heat waves and practice of protective measures against it were poor among respondents. A health education intervention on heat waves and how to prevent its negative health impacts was conducted in the community.

Key messages

Due to poor knowledge of heat waves and its negative health effects, practice of protective measures against it was poor among respondents. There is need for more public health response to address this rural public health challenge.

Serial electrophysiology in Guillain-Barré syndrome: A retrospective cohort and case-by-case multicentre analysis

OBJECTIVES

To assess the usefulness of serial electrophysiology in Guillain-Barré syndrome (GBS) in a multicenter setting and the reasons for change in electrodiagnostic subtypes with serial studies.

METHODS

We retrospectively analysed serial electrophysiology of 51 patients with GBS from 4 European centres. Proportions of subtypes were determined at each timing. Individual case analyses were also performed where diagnostic changes occurred with either criteria, to ascertain if changes were due to disease progression or criteria inadequacy.

RESULTS

At first study, comparing old vs new criteria, acute inflammatory demyelinating polyneuropathy (AIDP) was diagnosed in 70.6% vs 51%, axonal GBS in 15.7% vs 39.2%, equivocal forms in 11.8% vs 7.8%. At second study, AIDP was diagnosed in 72.5% vs 52.9%, axonal GBS in 9.8% vs 33.3%, equivocal forms in 15.7% vs 11.7%. Subtype proportions were unchanged, indicating serial studies did not, in the cohort, alter diagnostic rates for each subtype irrespective of criteria used. Individual review of cases where subtype electrodiagnosis changed indicated suboptimal specificity for AIDP/sensitivity for axonal GBS as main cause of diagnostic shifts with old criteria, whereas disease progression explained most changes with new criteria (55.6% vs 81.8%; P = .039).

CONCLUSIONS

Serial electrophysiology is unhelpful in GBS. Repeat studies cannot represent the gold standard as electrodiagnosis may alter due to disease progression. Changes in electrodiagnosis relate more often to disease progression with new criteria but are more frequently due to suboptimal sensitivity/specificity with old criteria. A single electrophysiological study using the most accurate available criteria appears sufficient in GBS.

House Dust Mites in Human ear

A study was carried out to investigate the presence of mites in human ear in 58 patients (113 ears). Ear scrapings were examined under the microscope by a parasitologist for the presence of house dust mites. Results showed the presence of house dust mites in 8 (7.1%) ears. We can conclude that mites are normal commensals of the external ears in tropical countries.

Nanoplasmonics tuned "click chemistry"

Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised "click" reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the "click" chemistry.

Acanthamoeba genotype T4 detected in naturally-infected feline corneas found to be in homology with those causing human keratitis

A total of 10 out of 65 cornea swab samples from cats with eye symptoms showed Acanthamoeba-like morphology after cultivation. By PCR and DNA sequencing of Acanthamoeba diagnostic fragment 3 (DF3), all 10 isolates from the positive samples were categorized into two homologous groups of AfC1 (PM1, PM2, PM3, PF6, KM7, KF8, KMK9) and AfC2 (PM4, PM5, KFK10) due to the presence of bases A(354) and G(354), respectively. Furthermore, DF3 of AfC1 and AfC2 showed 100% similarity with Genbank reference isolates with the accession numbers DQ087314, EU146073 and U07401, GU808323, which were Acanthamoeba castellanii strains genotype T4 originating from human keratitis. This finding suggests that A. castellani strains have the capability to infect cats and human under favorable conditions.

Psychatric morbidity among third year medical students at Ain Shams University, Cairo, Egypt

Background

Mental distress among medical students is often reported. Different psychiatric disorders are found to be under recognized yet common and treatable among medical students. Various previous studies have shown that medical students are subjected to considerable stress over the last decades. The aim of this study was to determine the presence of clinically significant psychiatric morbidity among third year medical students, to explore the effects of the socio demographic background for these outcomes and to analyze gender differences regarding selected psychiatric morbidities.

Methods

A cross sectional study is carried out among third year medical students from Ain Shams University. They were assessed using Social Classification Scale and Structured Clinical Interview for DSM-IV (SCID I) to assess psychiatric morbidity.

Results

Response rate was 98.9%. Prevalence of psychiatric morbidity among our medical students sample was 59.9%. No significant statistical association between psychological morbidity and any of the socio demographic variables. The most prevalent psychiatric diagnosis was found to be depression (47.9%), followed by Generalized Anxiety Disorder (GAD) (44.9%) & Obsessive Compulsive Disorder (OCD) (44.4%). The least prevalent of which was Anorexia Nervosa (0.7%).

Conclusion

Significantly high proportion of medical students (59.9%) had ongoing psychiatric condition and that proactive interventions should be addressed to encourage those medical students to seek help for their psychiatric problems. Counseling and preventive mental health services should be an integral part of the routine clinical facilities caring for medical students.

Interstitial deletion of proximal 8q including part of the centromere from unbalanced segregation of a paternal deletion/marker karyotype with neocentromere formation at 8p22

BACKGROUND/AIMS

The 'McClintock mechanism' of chromosome breakage and centromere misdivision, in which a deleted chromosome with its concomitant excised marker or ring chromosome is formed, has been described in approximately one dozen reports. We report a case of a girl with short stature, developmental delay, and dysmorphic features.

METHODS

Analysis was performed on the proband and father using cytogenetic chromosome analysis and the Affymetrix 6.0 SNP microarray. Fluorescence in situ hybridization (FISH) using a chromosome 8 alpha-satellite probe and immunofluorescence with antibodies to CENP-C were used to examine the centromere positions in these chromosomes.

RESULTS

An abnormal chromosome 8 with a cytogenetically visible deletion was further defined by SNP array as a 10.6-Mb deletion from 8q11.1→q12.1. FISH with a chromosome 8 alpha-satellite probe demonstrated that the deletion removed a significant portion of the pericentromeric alpha-satellite repeat sequences and proximal q arm. The deleted chromosome 8 appeared to have a constriction at 8p22, suggesting the formation of a neocentromere, even though alpha-satellite sequences still appeared at the normal location. Chromosome analysis of the phenotypically normal father revealed the same deleted chromosome 8, as well as an apparently balancing mosaic marker chromosome 8. FISH studies revealed that the majority of the chromosome 8 alpha-satellite DNA resided in the marker chromosome. Immunofluorescence studies with antibodies to CENP-C, a kinetochore protein, proved the presence of a neocentromere at 8p22. The excision of the marker from the deleted chromosome 8 likely necessitated the formation of a new kinetochore at the 8p22 neocentromere to stabilize the chromosome during mitosis.

CONCLUSION

This case clearly illustrates the utilization of classic cytogenetics, FISH, and array technologies to better characterize chromosomal abnormalities and provide information on recurrence risks. It also represents a rare case where a neocentromere can form even in the presence of existing alpha-satellite DNA.

Engineering a safe landing: engaging medical practitioners in a systems approach to patient safety

BACKGROUND

Several event studies, including the Australian Safety and Quality in Healthcare Study, emphasize gaps in safety for hospitalized patients. It is now recognized that system-based factors contribute significantly to risk of adverse events and this has led to a shift in focus of patient safety from the autonomous responsibility of medical clinicians to a systems-based approach. The aim of this study was to determine medical practitioner awareness of, level of engagement in and barriers to engagement in a systems approach to patient safety and quality.

METHODS

Information from acute and subacute care medical practitioners at a metropolitan public hospital was collected within an anonymous structured electronic survey, a discussion group and key informant interviews.

RESULTS

There were 73 survey respondents (response rate 7.6%). Fifty-one (69.9%) were unaware of the Institute of Medicine report 'To Err is human'. Thirty-six (49.3%) were unaware of the Australian Quality in Healthcare Study and 12 (16.4%) had read the article. There was a positive relation identified between awareness and seniority. There was a low level of participation in systems-focused quality and safety activities and limited understanding of the role of systems in medical error causation. There was uncertainty about the changing role of medical practitioners in patient safety and perceived lack of skills to effectively engage with hospital management about safety and quality issues.

CONCLUSION

Several factors are limiting engagement of medical practitioners in a systems approach to patient safety. Increased educational support is needed and may be best focused within clinical effectiveness activities pertinent to practitioner interest and expertise.

Adulticidal activity of some Malaysian plant extracts against Aedes aegypti Linnaeus

The adulticidal activity of methanol extracts from three Malaysian plants namely Acorus calamus Linn., Litsea elliptica Blume and Piper aduncum Linn. against adult of Aedes aegypti (L.) were studied. Standard WHO bioassay tests were used to evaluate the effectiveness of these plant extracts. The hexane fraction from methanol extract of Acorus calamus rhizome was the most effective, exhibiting LC50 and LC90 values of 0.04 mgcm(-2) and 0.09 mgcm(-2) respectively. For L. elliptica, the methanol fraction also displayed good adulticidal property with the LC50 and LC90 values of 0.11 mgcm(-2) and 6.08 mgcm(-2) respectively. It is found that hexane fraction of the P. aduncum crude extract was the least effective among the three plants showing LC50 and LC90 values of 0.20 mgcm(-2) and 5.32 mgcm(-2), respectively. However, although A. calamus showed lowest LC values, the LT50 results indicated that the methanol fraction of L. elliptica was most potent extract among the extracts tested.

The impact of induction duration and the number of high-dose cycles on the long-term survival of women with metastatic breast cancer treated with high-dose chemotherapy with stem cell rescue: an analysis of sequential phase I/II trials from the Dana-Farber/Beth Israel STAMP program

Although high-dose chemotherapy (HDC) with stem cell rescue for the treatment of women with metastatic breast cancer (MBC) is currently a controversial strategy, we report the long-term outcomes of women undergoing high-dose therapy for MBC over the past 12 years while participating in a sequence of research studies transitioning between a single to a double intensification approach. Univariate and multivariate analyses provide a framework to understand the prognostic factors important for event-free and overall survival. Between May 1988 and April 1998, we enrolled 188 women with MBC into 3 trials of previously reported sequential transplantation strategies. Trial I (long induction/single transplantation) accepted 62 women in partial or complete response to an unspecified induction therapy and treated them with high-dose CTCb (cyclophosphamide, thiotepa, and carboplatin) supported by marrow or peripheral blood progenitor cells (PBPC). Trial II (long induction/double transplantation) accepted 68 women in partial or complete response to an unspecified induction therapy, and mobilized stem cells with 2 cycles of AF (doxorubicin and 5-fluorouracil) with granulocyte colony-stimulating factor (G-CSF). These women then received 1 cycle of high-dose single-agent melphalan followed 3 to 5 weeks later by CTCb, each with marrow or PBPC support. Trial III (short induction/double transplantation) enrolled 58 women prior to chemotherapy treatment for metastatic disease. Induction/mobilization consisted of 2 cycles given 14 days apart of doxorubicin and G-CSF. In contrast to trials I and II, patients with stable disease or better response to induction were eligible to proceed ahead with 2 cycles of HDC, 1 being CTCb and the other being dose escalated paclitaxel together with high-dose melphalan (TxM). These 2 HDC regimens were administered 5 weeks apart. TxM was given first in 32 patients and CTCb was given first in 26 patients. The median follow-up periods for trials I, II, and III were 98, 62, and 39 months from the initiation of induction chemotherapy and 92, 55, and 36 months from last high-dose therapy, respectively. The patient characteristics upon entry into these trials were similar. Important differences were that only those patients achieving a partial response or better to induction therapy were enrolled and analyzed for trials I and II, but all patients were analyzed on an intent-to-treat basis for trial III, including those who did not receive intensification. The median event-free survival (EFS) times from induction chemotherapy were 13, 19, and 27 months for trials I, II, and III, respectively (III versus I + II, P = .0004; III versus I, P = .0005; III versus II, P = .005; II versus I, P = .25). The median overall survival (OS) times from induction chemotherapy were 30, 29, and 57 months for trials I, II, and III, respectively (III versus I + II, P = .002; III versus I, P = .003; III versus II, P = .009; II versus I, P = .47). By multivariate Cox regression, participation in the short induction/double transplantation trial III and having no prior adjuvant chemotherapy remained favorable prognostic factors for both EFS and OS. The presence of visceral disease shortened EFS, and hormone sensitivity was of borderline significance. No substantive differences in the characteristics of the patient populations between the 3 trials appeared to interact with outcomes. In conclusion, we found that single transplantation in responding patients after long induction achieves a small cohort of long-term survivors, similar to the results reported by other transplantation centers. Adding a cycle of single-agent high-dose melphalan in this context delayed median time to relapse but did not affect long-term EFS or OS. The double transplantation approach using CTCb and TxM early in the course of treatment was associated with the best EFS and overall survival and was safe, feasible, and tolerable. Treatment duration was only 14 weeks, and this treatment option eliminated lengthy induction chemotherapy. Although selection biases may have in part contributed to this effect, a randomized comparison of standard therapy versus short induction/double transplantation is warranted.

Structural characterization of a 2'F-RNA aptamer that binds a HIV-1 SU glycoprotein, gp120

Here we describe the isolation of specific 2'F-substituted RNA ligands for the SU glycoprotein, gp120, of HIV-1 strain HXB2. These aptamers bind the target protein with an affinity of the order of 10(-7) M. Binding was specific to SU glycoprotein and directed to a non-neutralizing epitope that was not shared with the related strain, HIV-1(BaL). The structure of one aptamer was defined by a combination of deletion analysis and enzymatic probing studies, revealing a 42 nt minimal element comprising a three-helix junction that retained the binding affinity of the parental sequence. Interestingly, binding to SU glycoprotein was accompanied by structural changes in the aptamer that stabilized the weakest of the 3 helices.

Implications of microscopic satellites of the primary and extracapsular lymph node spread in patients with high-risk melanoma: pathologic corollary of Eastern Cooperative Oncology Group Trial E1690

PURPOSE

To correlate the presence of extracapsular spread (ECS) of regional nodal metastases, and micrometastasis near the primary tumor, with disease outcome in the intergroup study E1690 in relation to the impact of recombinant interferon-alfa (rIFN alpha)-2b.

PATIENTS AND METHODS

E1690 included 642 patients with American Joint Committee on Cancer stage IIB or III cutaneous melanoma. Patients were randomized into high- and low-dose rIFN alpha-2b treatment arms and an observation arm. Pathologic slides were reviewed for selected parameters from at least half of the subjects in all three arms. Evaluation of the primary tumor included notations regarding ulceration, mitotic activity, thickness, microscopic satellites (MS), and nodal ECS on a standardized pathology form. These data were collated in relation to relapse-free survival (RFS) and overall survival (OS) at 50 months' follow-up and studied using Cox regression analysis.

RESULTS

Ulceration, mitotic activity, thickness, and size of tumor-bearing lymph nodes did not show a statistically significant correlation with either OS or RFS across all treatment arms. The presence of MS was correlated with RFS (P =.0008) and OS (P =.05). ECS correlated with RFS (hazard ratio = 1.44, P =.032) but not OS (P =.11).

CONCLUSION

The presence of MS (in 6% [18 of 308 patients]) had a significant adverse impact on both RFS (P =.0008) and OS (P =.053). Ulceration, mitotic activity, thickness, and number of positive lymph nodes had no significant effect on OS in this subset study (univariate or multivariate Cox analysis). The presence of ECS in lymph nodes had a significant adverse effect on RFS (P =.032) but not on OS.

A short course of induction chemotherapy followed by two cycles of high-dose chemotherapy with stem cell rescue for chemotherapy naive metastatic breast cancer: sequential phase I/II studies

Two cycles of high-dose chemotherapy with stem cell support (HDC) may increase the total dose delivered and dose intensity. A brief induction phase and different non-cross-resistant agents for each HDC cycle were used to avoid drug resistance. Twenty-six women with metastatic BC had induction and stem cell mobilization with two cycles of doxorubicin/G-CSF given every 14 days. Patients with stable disease or better after induction received HD CTCb followed by HD melphalan and dose-escalated paclitaxel. At 475 mg/m(2) of paclitaxel by 24-h infusion, dose-limiting transient peripheral sensory neuropathy was encountered. No toxic deaths occurred. Complete and near complete response after completion of therapy was achieved in 22 (85%) of 26 patients. The median EFS was 38 months. The median OS has not yet been reached. At a median follow-up of 33 (25-43) months, actuarial EFS and OS were 54% (95% confidence interval (CI), 39-69%) and 69% (95% CI, 56-79%), respectively. This double transplant approach lasts only 14 weeks and is feasible, safe, and tolerable. Whilst selection biases may in part contribute to favorable EFS and OS, a randomized comparison of standard therapy vs double transplant in both metastatic and locally advanced breast cancer is warranted.

Testing for bias in weighted estimating equations

It is very common in regression analysis to encounter incompletely observed covariate information. A recent approach to analyse such data is weighted estimating equations (Robins, J. M., Rotnitzky, A. and Zhao, L. P. (1994), JASA, 89, 846-866, and Zhao, L. P., Lipsitz, S. R. and Lew, D. (1996), Biometrics, 52, 1165-1182). With weighted estimating equations, the contribution to the estimating equation from a complete observation is weighted by the inverse of the probability of being observed. We propose a test statistic to assess if the weighted estimating equations produce biased estimates. Our test statistic is similar to the test statistic proposed by DuMouchel and Duncan (1983) for weighted least squares estimates for sample survey data. The method is illustrated using data from a randomized clinical trial on chemotherapy for multiple myeloma.

Toxocara seroprevalence and childhood asthma among Malaysian children

BACKGROUND

The larva of Toxocara spp., a common animal roundworm, may infect non-compatible hosts, causing a profound immunological reaction with marked eosinophil and IgE responses, not unlike in atopy. In this study, we determined the seroprevalence of Toxocara exposure in 66 asthmatic and 58 non-asthmatic children.

METHODS

Exposure to Toxocara was determined by examining the serum samples of the children for specific IgG antibodies to L2 Toxocara larvae, using a commercially available diagnostic kit.

RESULTS

There was no significant difference in the mean age, sex, social class, residence type and presence of domestic pets at home between the two children groups. Children with bronchial asthma were observed to have higher Toxocara seropositivity than that of the non-asthmatic controls (21.2 vs 8.6%, P=0.047).

CONCLUSION

The observed relationship between exposure to Toxocara infection and bronchial asthma in Malaysian children warrants further evaluation. An understanding of any possible contribution to the pathogenesis of childhood asthma provides a potential avenue for prevention.

Genetic and dietary factors affecting human metabolism of 1,3-butadiene

The objective of this project was to determine the factors associated with differences in butadiene (BD) inhalation uptake and the rate of metabolism for BD to epoxy butene by monitoring exhaled breath during and after a brief exposure to BD in human volunteers. A total of 133 subjects (equal males and females; four racial groups) provided final data. Volunteers gave informed consent and completed a questionnaire including diet and alcohol use. A venous blood sample was collected for genotyping CYP2E1. Subjects received a 20 min exposure to 2.0 ppm of BD, followed by a 40 min washout period. The total administered dose was 0.6 ppm*h, which is in the range of everyday exposures. Ten, 1 or 2 min exhaled breath samples (five during and five after exposure) were collected using an optimized strategy. BD was determined by GC-FID analysis. Breathing activity (minute ventilation, breath frequency and tidal volume) was measured to estimate alveolar ventilation. After the washout period, 250 mg of chlorzoxazone were administered and urine samples collected for 6 h to measure 2E1 phenotype. The total BD uptake during exposure (inhaled BD minus exhaled) was estimated. A three-compartment PBPK model was fitted to each subject's breath measurements to estimate personal and population model parameters, including in-vivo BD metabolic rate. A hierarchical Bayesian PBPK model was fit by Monte Carlo simulations to estimate model parameters. Regression and ANOVA analyses were performed. Earlier data analysis showed wide ranges for both total uptake BD and metabolic rate. Both varied significantly by sex and age, and showed suggestive differences by race, with Asians having the highest rates. The analyses reported here found no correlation between total BD uptake and metabolic rate. No significant differences were found for oxidation rates by 2E1 genotype or phenotype, but the rates showed trends consistent with reported differences by genotype and phenotype for chlorzoxazone metabolism. No effects on metabolic rate were observed for long-term alcohol consumption, or consumption in the past 24 h. Overall, neither dietary factors nor genetic differences explained much of the wide variability in metabolic rates. Population characteristics, age, sex, and race, were the most important explanatory variables, but a large fraction of the total variability in metabolism remains to be explained.

High-dose interferon alfa-2b does not diminish antibody response to GM2 vaccination in patients with resected melanoma: results of the Multicenter Eastern Cooperative Oncology Group Phase II Trial E2696

PURPOSE

High-dose interferon alfa-2b (IFNalpha2b) is the only established adjuvant therapy of resectable high-risk melanoma. GM2-KLH/QS-21 (GMK) is a chemically defined vaccine that is one of the best developed of a range of vaccine candidates for melanoma. A single-institution phase III trial conducted at Memorial Hospital served as the impetus for an intergroup adjuvant E1694/S9512/C509801 trial, which recently completed enrollment of 880 patients. To build on the apparent benefit of IFNalpha2b in resectable high-risk American Joint Committee on Cancer (AJCC) stage IIB or III melanoma, this phase II study was designed to evaluate the combination of GMK and IFNalpha2b. The E2696 trial was undertaken to evaluate the toxicity and other effects of the established adjuvant high-dose IFNalpha2b regimen in relation to immune responses to GMK and to evaluate the potential clinical and immunologic effects of the combined therapies.

PATIENTS AND METHODS

This trial enrolled 107 patients with resectable high- or very high-risk melanoma (AJCC stages IIB, III, and IV).

RESULTS

The results demonstrate that IFNalpha2b does not significantly inhibit immunoglobulin M or G serologic responses to the vaccine and that the combination of high-dose IFNalpha2b and GMK is well tolerated in this patient population.

CONCLUSION

Cox analysis of the results of the combination with IFNalpha2b show improvement in the relapse-free survival of patients with very high-risk melanoma (including those with resectable M1 disease).

Incidence of post transplant myelodysplasia/acute leukemia in non-Hodgkin's lymphoma patients compared with Hodgkin's disease patients undergoing autologous transplantation following cyclophosphamide, carmustine, and etoposide (CBV)

Secondary malignancies, particularly myelodysplasia (MDS), are serious events following high dose therapy with autologous stem cell support. We observed a higher frequency of secondary malignancies in patients with Hodgkin's disease (HD) than in patients with non-Hodgkin's lymphoma (NHL) undergoing high dose therapy with the same non-TBI conditioning regimen. Three hundred patients with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) were treated with cyclophosphamide, carmustine and etoposide and autologous stem cell support from 1986 through 1994. Median follow up of survivors is 3.9 years. Five-year survival is 51% for HD and 48% for NHL. Eleven patients developed second malignancies (9/150 treated for HD vs. 2/150 treated for NHL) a median of 2.4 years from transplantation and 5.2 years from initial diagnosis. Six patients had myelodysplasia or acute leukemia (MDS/AML) and 5 had lymphomas or solid tumors. Actuarial risk of MDS/AML at five years for patients transplanted for non-Hodgkin's lymphoma is 3% (95% CI 0.6-9.6%). HD patients had significantly different pretreatment characteristics than patients with NHL. A Cox model showed that greater number of prior relapses and prior radiation therapy were significant risk factors for the development of MDS/AML. These data suggest that CBV is associated with a lower risk of secondary MDS/AML than TBI containing regimens and that much of the risk is associated with the pre-transplantation therapy. The use of autotransplantation early in the course of therapy for relapsed lymphoma might prevent some cases of MDS/AML.

A short course of induction chemotherapy followed by two cycles of high-dose chemotherapy with stem cell rescue for chemotherapy naive metastatic breast cancer

A single cycle of high-dose chemotherapy with stem cell support (HDC) in women with responsive metastatic breast cancer (BC) consistently achieves over 50% complete and near complete response (CR/nCR). This significant cytoreduction results in a median event-free survival (EFS) of 8 months, and approximately 20% 3-year and 16% 5-year EFS in selected patients. To improve long-term outcomes, new strategies to treat minimal residual tumor burden are needed. Increased total dose delivered can be achieved with two cycles of HDC. Critical design issues include shortening induction chemotherapy to avoid development of drug resistance and the use of different agents for each HDC cycle. We have determined the maximum tolerated dose (MTD) for paclitaxel combined with high-dose melphalan in the context of a double transplant and explored the impact of a short induction phase. Between June 1994 and August 1996, we enrolled 32 women with metastatic BC on to this phase I double transplant trial. Induction consisted of doxorubicin 30 mg/m2/day days 1-3 given for 2 cycles every 14 days with G-CSF 5 microg/kg s.c. days 4-12. Stem cell collection was performed by leukapheresis in each cycle when the WBC recovered to above 1000/microl. Patients with stable disease or better response to induction were eligible to proceed with HDC. HDC regimen I (TxM) included paclitaxel with dose escalation from 0 to 300 mg/m2 given on day 1 and melphalan 180 mg/m2 in two divided doses given on day 3. HDC regimen II was CTCb (cyclophosphamide 6 g/m2, thiotepa 500 mg/m2, and carboplatin 800 mg/m2 total doses) delivered by 96-h continuous infusion. At the first dose level of 150 mg/m2 paclitaxel by 3 h infusion, four of five patients developed dose-limiting toxicity consisting of diffuse skin erythema and capillary leak syndrome. Only two of these five completed the second transplant. Subsequently, paclitaxel was delivered by 24-h continuous infusion together with 96 h of dexamethasone and histamine receptor blockade. This particular toxicity was not observed again. No toxic deaths occurred and dose-limiting toxicity was not encountered. Three patients were removed from study prior to transplant: one for insurance refusal and two for disease progression. All others completed both cycles of transplant. Complete and near complete response (CR/nCR) after completion of therapy was achieved in 23 (72%) of 32 patients. The median EFS is 26 months. The median overall survival has not yet been reached. At a median follow-up of 58 months, EFS and overall survival are 41% and 53%, respectively. This double transplant approach is feasible, safe, and tolerable. Treatment duration is only 14 weeks and eliminates lengthy induction chemotherapy. The observed event-free and overall survivals are promising and are better than expected following a single transplant. Whilst selection biases may in part contribute to this effect, a much larger phase II double transplant trial is warranted in preparation for a potential randomized comparison of standard therapy vs single vs double transplant.

Prognostic factors in metastatic melanoma: a pooled analysis of Eastern Cooperative Oncology Group trials

PURPOSE

To identify factors that are prognostic for survival in patients with metastatic melanoma treated in eight Eastern Cooperative Oncology Group (ECOG) trials conducted over the past 25 years.

METHODS

We identified common, significant patient characteristics collected at baseline on 1,362 eligible patients for inclusion in a pooled analysis. Proportional hazards models were used to examine simultaneously the effects of multiple covariates on survival.

RESULTS

Median survival was 6.4 months (95% confidence interval, 6.1 to 6.9 months.) Factors conferring the greatest increased risk of death included number of metastatic sites (relative risk [RR] = 1.12), ECOG performance status of 1 or more (RR = 1.49), or metastatic disease in the gastrointestinal (GI) tract (RR = 1.49), liver (RR = 1.44), pleura (RR = 1.35), or lung (RR = 1.19). Prior immunotherapy (RR = 0.84) and female sex (RR = 0. 87) were associated with prolonged survival. Although only 12% of patients responded to protocol treatment, landmark analysis showed this to be a significant prognostic factor (RR = 0.57). A model based on three recent studies in which baseline values for alkaline phosphatase, lactate dehydrogenase (LDH), and platelets were available identified an increased number of sites of metastasis (RR = 1.30), abnormal LDH (RR = 1.89), abnormal alkaline phosphatase (RR = 1.76), abnormal platelets (RR = 1.63), and GI metastases (RR = 1. 66) as prognostic for poorer survival. Response to treatment, when examined by landmark analysis of studies with laboratory parameters, was associated with decreased risk of death (RR = 0.47).

CONCLUSION

This study demonstrates the importance and utility of laboratory parameters as prognostic factors for survival and confirmed the deleterious effects of multiple metastatic sites. Prior immunotherapy and female sex were associated with improved prognosis. Prognostic factors identified in this analysis are consistent with the findings of prior published studies and argue for the adoption of laboratory findings in the staging systems that are used for entry and stratification of clinical trials in the future.

Action of angiotensin II on DNA synthesis by human saphenous vein in organ culture

Angiotensin II (Ang II), an effector peptide of the renin-angiotensin system, has been reported to stimulate growth of blood vessels in vivo and smooth muscle cells in culture. In this study, the effect of Ang II on DNA synthesis was examined in deendothelialized human saphenous vein in organ culture. After 7 days' exposure to medium containing 0.4% fetal calf serum plus Ang II, there was a marked increase in DNA synthesis. The effect of Ang II was comparable to the response to platelet-derived growth factor. Responses to Ang II were partially inhibited by the AT(1) receptor antagonist candesartan. An AT(2) receptor antagonist, PD123319, had no effect on Ang II-induced DNA synthesis, either alone or in combination with candesartan. The Ang II peptide analogues [Sar(1), Ile(8)]-Ang II (saralasin) and [Sar(1),Thr(8)]-Ang II (sarthran) acted as agonists, increasing DNA synthesis. In the presence of saralasin, responses to Ang II were inhibited. Tyrphostin-23, a tyrosine kinase inhibitor, prevented Ang II-induced DNA synthesis and reduced DNA synthesis in tissues incubated in medium containing only 0.4% fetal calf serum. In conclusion, Ang II stimulates DNA synthesis in human saphenous vein in organ culture. The effect of Ang II was more marked than has been previously reported in isolated cultured saphenous vein smooth muscle cells, and this effect is mediated in part by an angiotensin type 1 receptor. It is possible that an undefined receptor for Ang II may also be involved in the stimulation of DNA synthesis in this preparation.