Understanding the phases of vaccine hesitancy during the COVID-19 pandemic

Vaccine hesitancy is an important feature of every vaccination and COVID-19 vaccination is not an exception. During the COVID-19 pandemic, vaccine hesitancy has exhibited different phases and has shown both temporal and spatial variation in these phases. This has likely arisen due to varied socio-behavioural characteristics of humans and their response towards COVID 19 pandemic and its vaccination strategies. This commentary highlights that there are multiple phases of vaccine hesitancy: Vaccine Eagerness, Vaccine Ignorance, Vaccine Resistance, Vaccine Confidence, Vaccine Complacency and Vaccine Apathy. Though the phases seem to be sequential, they may co-exist at the same time in different regions and at different times in the same region. This may be attributed to several factors influencing the phases of vaccine hesitancy. The complexities of the societal reactions need to be understood in full to be addressed better. There is a dire need of different strategies of communication to deal with the various nuances of all of the phases. To address of vaccine hesitancy, an understanding of the societal reactions leading to various phases of vaccine hesitancy is of utmost importance.

Do proximal hip geometry, trabecular microarchitecture, and prevalent vertebral fractures differ in postmenopausal women with type 2 diabetes mellitus? A cross-sectional study from a teaching hospital in southern India

This study from southern India showed that the trabecular microarchitecture and proximal hip geometry were significantly impaired in postmenopausal women with diabetes as compared to age and BMI matched non-diabetic controls. This is despite there being no significant difference in bone mineral density at the femoral neck and hip not between both groups. One-third of the study subjects with type 2 diabetes had prevalent vertebral fractures. Bone mineral density assessment as a standalone tool may not adequately reflect bone health in subjects with diabetes.

INTRODUCTION

There is limited information with regard to bone health in Indian postmenopausal women with type 2 diabetes. We studied the bone mineral density (BMD), trabecular bone score (TBS), prevalent vertebral fractures (VF), proximal hip geometry, and bone mineral biochemistry in ambulatory postmenopausal women with and without type 2 diabetes mellitus (T2DM).

METHODS

This was a cross-sectional study conducted at a tertiary care center. BMD, TBS, prevalent vertebral fractures, and hip structural analysis (HSA) were assessed using a dual-energy X-ray absorptiometry (DXA) scanner. Bone mineral biochemical profiles were also studied.

RESULTS

A total of 202 ambulatory postmenopausal women known to have type 2 diabetes mellitus with mean (SD) age of 65.6 (5.2) years and 200 age and BMI matched non-diabetic controls with mean (SD) age of 64.9 (4.7) years were recruited from the local community. Although the prevalence of lumbar spine osteoporosis was significantly lower among cases (30.7%) as compared to controls (42.9%), the prevalence of degraded bone microarchitecture (TBS < 1.200) was significantly higher among cases (51%) than in controls (23.5%); P < 0.001. Prevalent vertebral fractures were not significantly different in cases and controls. The various geometric indices of the proximal hip were significantly impaired in subjects with diabetes as compared to controls.

CONCLUSION

This study may highlight the utility of the trabecular bone score and hip structural analysis in subjects with diabetes, where the bone mineral density tends to be paradoxically high, and may not adequately predict fracture risk.

Vitamin D assessment and precision of clinical referrals: Insights gained from a teaching hospital in southern India

Objective:

Vitamin D deficiency is widely prevalent worldwide. This has led to a significant surge in referrals for vitamin D assessment in recent years. The cost-effectiveness and rationalization of this practice is uncertain. This study aimed to evaluate the referral pattern for vitamin D testing from a tertiary center in southern India.

Materials and Methods:

This was a cross-sectional study done over a period of one year (2017). A total of 95,750 individuals, referred for vitamin D screening were included in this study. Details regarding referring departments and indications for referral were obtained from the computerized hospital information processing system (CHIPS).

Results:

The study population exhibited a female preponderance (54.1%) with mean (SD) age of 40.3 (18.5) years. Overall, 44% were found to have vitamin D deficiency. Most of the referrals were from nephrology (15.4%), neurology (10.1%), and orthopedics (9.1%). Nevertheless, dermatology, the staff-clinic, and hematology which contributed to 3.3%, 1.7%, and 1.7% of referrals, had a higher proportion of vitamin D deficiency of 59.1%, 57.7%, and 64.6%, respectively. Although the most common indications for referral were generalized body aches (20.5%) and degenerative bone disorders (20.1%), the proportion of subjects with vitamin D deficiency referred for these indications were 46.1% and 41.6%, respectively. In contrast, chronic steroid use that accounted for 3.3% of the referrals had 59.1% of subjects who were deficient in vitamin D.

Conclusion:

To ensure a rational approach to vitamin D testing, clinicians ought to use their discretion to screen those truly at risk for vitamin D deficiency on a case to case basis and avoid indiscriminate testing of the same.

Prevalence of cirrhotic cardiomyopathy and its relationship with serum pro-brain natriuretic peptide, hepatorenal syndrome, spontaneous bacterial peritonitis, and mortality

OBJECTIVES

This study aims at estimating the prevalence of cirrhotic cardiomyopathy in a cohort of cirrhosis patients in northern India using the World Congress of Gastroenterology 2005 criteria and its relationship with grades of cirrhosis, its complications, and all-cause mortality.

METHODS

This was a prospective study in which 53 cirrhosis patients underwent the 2D color Doppler, and tissue Doppler echocardiography. Echocardiography findings were compared with thirty age- and sex-matched healthy controls. Additionally, serum pro-brain natriuretic peptide (pro-BNP) and troponin-T levels were measured. Patients were followed up for 6 months to look for complications and mortality.

RESULT

2D echocardiography findings revealed that diastolic cardiomyopathy with no gross systolic dysfunction was significantly prevalent in cirrhosis patients. Using the Montreal criteria, we found the incidence of diastolic cardiomyopathy to be 56.6%. Tissue Doppler echocardiography findings were also correlated. Diastolic dysfunction correlated with the severity of cirrhosis, and patients with higher Child score had more diastolic dysfunction. Serum pro-BNP levels and QTc interval were also higher in patients with diastolic dysfunction. On survival analysis, patients with cirrhotic cardiomyopathy had shorter survival and greater frequency of encephalopathy and hepatorenal syndrome (HRS) episodes as compared with cirrhotic patients without cardiomyopathy, though the differences were not statistically significant.

CONCLUSION

The study showed that diastolic dysfunction was highly prevalent (56.6% of the study population) in cirrhosis patients. QTc interval and pro-BNP were also significantly raised. Also, complications of cirrhosis like HRS, spontaneous bacterial peritonitis, and hepatic encephalopathy were more common in the cirrhotic cardiomyopathy group.

Implementation of "health systems approach" to improve vaccination at birth in institutional deliveries at public health facilities; experience from six states of India

INTRODUCTION

Newborn vaccination is an integral part of routine immunization program in India, but program implementation gaps exist. The focus of this article is to identify and describe an implementation strategy which could improve the newborn vaccination at the facility level.

MATERIALS AND METHODS

A situation analysis was conducted through a mixed-methods approach to identify the lacunae in the health system and the same was used to develop an implementation strategy to improve newborn vaccination coverage across the six priority states.

RESULTS

Issues in stewardship and human resource, vaccine-related stock-outs, and poor service delivery were some of the reasons for low facility-level vaccination coverage. After implementation of a health system-based strategy, the new born vaccination improved from 55% to 88% across 10 quarters of program implementation. Factors such as sensitization of stakeholders, vaccination on holidays, rigorous documentation, and supportive supervision of health staff were primary reasons for improvement in service delivery.

CONCLUSION

Importance of newborn immunization at birth is well established. The results from six states prove that "health systems approach" as an implementation strategy is a viable tool to improve newborn immunization at birth.

Remote ischemic preconditioning attenuates EGR-1 expression following myocardial ischemia reperfusion injury through activation of the JAK-STAT pathway

BACKGROUND/OBJECTIVES

Remote ischemic preconditioning (RIPC) protects the myocardium from ischemia/reperfusion (I/R) injury however the molecular pathways involved in cardioprotection are yet to be fully delineated. Transcription factor Early growth response-1 (Egr-1) is a key upstream activator in a variety of cardiovascular diseases. In this study, we elucidated the role of RIPC in modulating the regulation of Egr-1.

METHODS

This study subjected rats to transient blockade of the left anterior descending (LAD) coronary artery with or without prior RIPC of the hind-limb muscle and thereafter excised the heart 24h following surgical intervention. In vitro, rat cardiac myoblast H9c2 cells were exposed to ischemic preconditioning by subjecting them to 3cycles of alternating nitrogen-flushed hypoxia and normoxia. These preconditioned media were added to recipient H9c2 cells which were then subjected to 30min of hypoxia followed by 30min of normoxia to simulate myocardial I/R injury. Thereafter, the effects of RIPC on cell viability, apoptosis and inflammatory markers were assessed.

RESULTS

We showed reduced infarct size and suppressed Egr-1 in the heart of rats when RIPC was administered to the hind leg. In vitro, we showed that RIPC improved cell viability, reduced apoptosis and attenuated Egr-1 in recipient cells.

CONCLUSIONS

Selective inhibition of intracellular signaling pathways confirmed that RIPC increased production of intracellular nitric oxide (NO) and reactive oxygen species (ROS) via activation of the JAK-STAT pathway which then inactivated I/R-induced ERK 1/2 signaling pathways, ultimately leading to the suppression of Egr-1.

Vaccine hesitancy: understanding better to address better

Vaccine hesitancy is an emerging term in the socio-medical literature which describes an approach to vaccine decision making. It recognizes that there is a continuum between full acceptance and outright refusal of some or all vaccines and challenges the previous understanding of individuals or groups, as being either anti-vaccine or pro-vaccine. The behaviours responsible for vaccine hesitancy can be related to confidence, convenience and complacency. The causes of vaccine hesitancy can be described by the epidemiological triad i.e. the complex interaction of environmental- (i.e. external), agent- (i.e. vaccine) and host (or parent)- specific factors. Vaccine hesitancy is a complex and dynamic issue; future vaccination programs need to reflect and address these context-specific factors in both their design and evaluation. Many experts are of the view that it is best to counter vaccine hesitancy at the population level. They believe that it can be done by introducing more transparency into policy decision-making before immunization programs, providing up-to-date information to the public and health providers about the rigorous procedures undertaken before introduction of new vaccines, and through diversified post-marketing surveillance of vaccine-related events.

Improvement over time in outcomes for patients undergoing endoscopic therapy for Barrett's oesophagus-related neoplasia: 6-year experience from the first 500 patients treated in the UK patient registry

BACKGROUND

Barrett's oesophagus (BE) is a pre-malignant condition leading to oesophageal adenocarcinoma (OAC). Treatment of neoplasia at an early stage is desirable. Combined endoscopic mucosal resection (EMR) followed by radiofrequency ablation (RFA) is an alternative to surgery for patients with BE-related neoplasia.

METHODS

We examined prospective data from the UK registry of patients undergoing RFA/EMR for BE-related neoplasia from 2008 to 2013. Before RFA, visible lesions were removed by EMR. Thereafter, patients had RFA 3-monthly until all BE was ablated or cancer developed (endpoints). End of treatment biopsies were recommended at around 12 months from first RFA treatment or when endpoints were reached. Outcomes for clearance of dysplasia (CR-D) and BE (CR-IM) at end of treatment were assessed over two time periods (2008-2010 and 2011-2013). Durability of successful treatment and progression to OAC were also evaluated.

RESULTS

508 patients have completed treatment. CR-D and CR-IM improved significantly between the former and later time periods, from 77% and 56% to 92% and 83%, respectively (p<0.0001). EMR for visible lesions prior to RFA increased from 48% to 60% (p=0.013). Rescue EMR after RFA decreased from 13% to 2% (p<0.0001). Progression to OAC at 12 months is not significantly different (3.6% vs 2.1%, p=0.51).

CONCLUSIONS

Clinical outcomes for BE neoplasia have improved significantly over the past 6 years with improved lesion recognition and aggressive resection of visible lesions before RFA. Despite advances in technique, the rate of cancer progression remains 2-4% at 1 year in these high-risk patients.

TRIAL REGISTRATION NUMBER

ISRCTN93069556.

Status of DDT and pyrethroid resistance in Indian Aedes albopictus and absence of knockdown resistance (kdr) mutation

BACKGROUND & OBJECTIVES

Aedes albopictus is one of the vectors for dengue and chikungunya and emergence of pyrethroid resistance in this species could be of a major concern in controlling the vector. This study reports insecticide susceptibility status of Ae. albopictus to DDT and pyrethroids in some Indian populations and status of presence of knockdown resistance (kdr) mutations.

METHODS

Three to four day old adult female Ae. albopictus collected from Delhi, Gurgaon (Haryana), Hardwar (Uttarakhand), Guwahati (Assam) and Kottayam (Kerala) were bio-assayed with DDT (4%), permethrin (0.75%) and deltamethrin (0.05%) impregnated papers using WHO standard susceptibility test kit. Mosquitoes were PCRgenotyped for F1534C kdr-mutation in the voltage-gated sodium channel (VGSC) gene. DDT and pyrethroid resistant individuals were sequenced for partial domain II, III and IV of VGSC targeting residues S989, I1011, V1016, F1534 and D1794 where kdr mutations are reported in Ae. aegypti.

RESULTS

Adult bioassays revealed varying degree of resistance against DDT among five populations of Ae. albopictus with corrected mortalities ranging between 61 and 92%. Kerala and Delhi populations showed incipient resistance against permethrin and deltamethrin respectively. All other populations were susceptible for both the synthetic pyrethroids. None of the kdr mutations was detected in any of DDT, deltamethrin and permethrin resistant individuals.

INTERPRETATION & CONCLUSION

Ae. albopictus has developed resistance against DDT and there is emergence of incipient resistance against pyrethroids in some populations. So far, there is no evidence of presence of knockdown resistance (kdr) mutation in Ae. albopictus.

Core attributes of stewardship; foundation of sound health system

Stewardship is not a new concept for public policy, but has not been used to its optimum by the health policy-makers. Although it is being practiced in most successful models of health system, but the onus to this function is still due till date. Lately, few experts in World Health Organization (WHO) have realized its importance and have been raising the issue at different platforms to pursue the most important function of the health system i.e. stewardship. The core attributes of stewardship need to be understood in totality for better understanding of the concept. These core attributes, required for hassle free functioning of a health system, include responsible manager, political will, normative dimension, balanced interventionist and proponents of good governance.

Endoscopic ablation of Barrett's neoplasia with a new focal radiofrequency device: initial experience with the Halo60

Radiofrequency ablation (RFA) is an accepted treatment for the eradication of dysplastic Barrett's esophagus (DBE) and residual Barrett's esophagus after endoscopic resection of intramucosal adenocarcinoma. Circumferential balloon-based and focal catheter-based RFA devices are currently used (the Halo360 and Halo90). However, a new smaller focal ablation device (the Halo60) has been developed, which may be of benefit in patients with short tongues of Barrett's neoplasia, small residual islands, difficult anatomy, or strictures. We report the first use of this device in 17 patients with either DBE or residual Barrett's esophagus after endoscopic resection of intramucosal adenocarcinoma.

Elevated dark adaptation thresholds in traumatic brain injury

PRIMARY OBJECTIVE

To expand upon earlier findings of elevated dark adaptation (scotopic) thresholds in photosensitive individuals with traumatic brain injury (TBI).

METHODS AND PROCEDURES

To assess scotopic thresholds in individuals with TBI (n = 17) manifesting varying degrees of photosensitivity (mild, moderate or marked), but without retinal dysfunction, to those of non-photosensitive, visually-normal individuals (n = 21) using a hand-held dark adaptometer.

MAIN OUTCOMES AND RESULTS

The group mean scotopic threshold for the TBI group was significantly higher than that of the visually-normal group. Over 50% (nine out of 17) of the TBI group exhibited elevated thresholds. There was no correlation between the threshold value and degree of photosensitivity.

CONCLUSION

The elevated scotopic thresholds suggest an abnormality in cortical gain control. An anomalous adaptive response may develop due to cortical damage, thereby attenuating subjective light sensation.

Nucleated red blood cells in normal bone marrow for transplantation

AIM

Nucleated red blood cells (nRBCs) are indistinguishable from white cells, and therefore are counted by standard electronic cell counters as white cells. We sought to find a correlation between the number of nRBCs and the age of the bone marrow donor, and determine when to correct the total nucleated cell count (TNCC), when reporting graft data.

MATERIAL AND METHODS

Presence of nucleated red blood cells was evaluated in 117 samples of normal bone marrow from the donors aged 3 months to 52 years. The nRBCs were counted manually on the smear of bone marrow as the numbers of nucleated RBCper 100 of white cells. The TNCC was obtained from the automated hematological counter Sysmex 9500.

RESULTS

The number of nRBCs was substantial in the bone marrow of older donors (up to 44 per 100 of white cells). There was significantly higher number of nRBCs in the bone marrow of older donors. There was no statistically significant difference in the number of nRBCs between female and male bone marrow. The presence ofnRBC in Hematopoietic Progenitor Cell, Marrow (HPC, Marrow) products gives a falsely high cell dose as well as a falsely high dose of total and CD34+ cells per kg, when the flow cytometric dual platform count based on International Society ol Hematotherapy and Graft Eunineering guidelines is utilized (ISHAGE).

CONCLUSIONS

The outcome of the bone marrow transplantation depends on the total nucleated cells dose, and the dose of CD344 cells/kg. It is therefore important to evaluate correctly the quality of the graft. We propose, that the rule of correction for nRBCs in bone marrow for transplantation should be applied if the number of nucleated red blood cells is > or = 5 per 100 of white blood cells.

Predictive value of alarm features in a rapid access upper gastrointestinal cancer service

AIMS

(i) To determine the value of individual alarm features for predicting cancer in subjects referred to a rapid access upper gastrointestinal cancer service; and (ii) to develop a clinical prediction model for cancer and to prospectively validate this model in a further patient cohort.

METHODS

Patient demographics, referral indications, and subsequent diagnosis were recorded prospectively. Logistic regression analyses were employed to determine the predictive value of individual alarm features in an evaluation cohort of 1852 consecutive cases. The potential impact of applying a modified set of referral criteria was then examined in a validation cohort of 1785 patients.

RESULTS

Evaluation cohort: mean age was 59 years; cancer prevalence 3.8%; and serious benign pathology 12.8%. Dysphagia (odds ratio (OR) 3.1), weight loss (OR 2.6), and age >55 years (OR 9.5) were found to be significant predictive factors for cancer but the value of other accepted alarm features was more limited. In particular, uncomplicated dyspepsia in those over 55 years was a negative predictive factor for cancer within this high risk cohort (OR 0.1). Validation cohort: the clinical prediction model would have selected 92% of cancer patients for fast track investigation while reducing the "two week rule" workload by 572 cases (31%).

CONCLUSIONS

Fast track endoscopy in subjects fulfilling current criteria for suspected upper gastrointestinal malignancy results in a significant yield of cancer ( approximately 4%) and serious benign diseases such as peptic ulceration, strictures, and severe oesophagitis (13%). However, the predictive value of individual features for cancer varies widely. Uncomplicated dyspepsia in older subjects was a poor predictor of cancer. Application of narrower referral criteria for accessing fast track services may reduce pressures while retaining high sensitivity for cancer.

Transformation of solitary osteochondroma calcaneum to chondrosarcoma--a case report

Solitary osteochondroma of calcaneum is an uncommon benign tumor. Its malignant transformation to chondrosarcoma is rarely encountered. Pain and recent enlargement are clinical manifestations of this complication. Magnetic resonance imaging is a valuable tool to detect this change.

Dissatisfaction with consent for diagnostic gastrointestinal endoscopy

INTRODUCTION

Little is known about patients' perspectives on the amount of information they receive prior to diagnostic gastrointestinal endoscopies. Our unit's policy for obtaining consent consists of initially posting an information leaflet to the patient followed by subsequent explanation of the procedure on arrival for the test. The consent form is signed by the patient immediately prior to the test.

METHODS

A questionnaire survey was conducted to assess patient perception and satisfaction with the amount of information received before diagnostic endoscopy.

RESULTS

The information was obtained from 127 of the 175 questionnaires that were distributed. Whereas 97% had read the information leaflet, only 52% had read the consent form before signing it. 64/127(51%) felt dissatisfied because they would have wanted more information while 3% were dissatisfied because they would have liked less information relating to one or more aspects of the test. Dissatisfaction was higher in patients who had not read the consent form (p < 0.001) and those with some formal education (p = 0.01).

CONCLUSIONS

Patients who did not read the consent form were more dissatisfied. Strategies to improve the rate of reading this document may increase patient satisfaction.

Alteration in ouabain-sensitive sodium potassium pump of erythrocytes during pregnancy induced hypertension: a kinetic study

The erythrocytes are widely used as model cells for studies of sodium-potassium pump (Na(+)-K(+) pump) in health and disease. Hence, to explore the possible role of the Na(+) transport across the cell membrane in the pathogenesis of pregnancy-induced hypertension (PIH), the present study was conducted to assess the Na(+)-K(+) pump functions in relation to its intrinsic kinetic properties using erythrocytes (RBC). Erythrocyte sodium concentration in pregnancy-induced hypertensive women was significantly (p<0.01) lower in comparison to normotensive pregnant women. On the contrary erythrocyte potassium was significantly higher (p<0.01) in PIH women as compared to normotensive pregnant women. Observed alterations in Na(+) and K(+) concentrations in erythrocytes were associated with significantly (p<001) increased Ouabain-sensitive sodium efflux rate and rate constants in erythrocytes from PIH women. Further, kinetic studies revealed that increased Ouabain-sensitive efflux rate constant in RBC from PIH women was accompanied by increased maximal velocity (V(max)) of Na(+)-K(+) pump. However, the affinity constant (K(m)) was unaltered in both the groups. Therefore, these findings suggest that increased Na(+)-K(+) pump activity in RBC of PIH women could be due to either increased numbers of Na(+)-K(+) pump units of increased numbers of active subunits of Na(+)-K(+) pump possibly due to specific plasma factors in PIH women.

Adenoviral infections and a prospective trial of cidofovir in pediatric hematopoietic stem cell transplantation

Adenoviral (ADV) infections are increasingly recognized as a cause of morbidity and mortality in pediatric hematopoietic stem cell transplantation (HSCT). We reviewed our experience with ADV infections in HSCT patients hospitalized for transplantation at Childrens Hospital Los Angeles January 1998 through December 1998. ADV was detected in 47% of patients, with recipients of HSCT from alternative donors (matched unrelated, unrelated cord, and mismatched related donors) being more frequently culture positive than recipients of HSCT from matched siblings (62% versus 27%, P = .04). Detection of ADV from 2 or more sites was associated with organ injury, eg, hemorrhagic cystitis, enteritis, and hepatitis. Because of the high incidence of ADV culture-positive patients and the lack of effective anti-ADV therapy, we initiated a prospective trial to evaluate cidofovir (CDV) in the treatment of ADV infections in HSCT recipients. Eight patients were enrolled on a dosage schedule of 1 mg/kg 3 times weekly. AD of these patients eventually achieved long-term viral suppression and clinical improvement, although 6 patients needed prolonged CDV therapy for up to 8 months before CDV could be stopped without ADV recurrence. We did not observe dose-limiting nephrotoxicity, and the discontinuation of the drug was not required in any patients. Prospective controlled trials to further define the role of CDV in the treatment of ADV infections in HSCT patients are warranted.

Hematopoietic stem cell transplantation: current status of old issues

Since 1968 hematopoietic stem cell transplantation (HSCT) has progressed from an experimental to standard therapeutic procedure. There are many obstacles to the successful outcome of HSCT procedures. Some of these obstacles are lack of healthy histocompatible donors, graft versus host disease, graft rejection and infections. Many advances have been made to overcome these obstacles with significant success. However, these issues and associated problems continue to persist at different levels as the field evolves with expanding indications for HSCT, use of alternative sources for hematopoietic stem cells and alternative transplant procedures. Newer interventions have allowed us to overcome some of these obstacles.

Hematopoietic stem cell transplantation for severe combined immune deficiency

Hematopoietic stem cell transplantation (HSCT) has been the definitive therapy for severe combined immune deficiency (SCID) since the first successful transplant for SCID in 1968. Improvements in the use of HSCT to treat patients with SCID are continuing. For example, during the last 5 years, the first successful in-utero HSCT, and the first success with gene therapy have occurred in patients with SCID. Debate still continues about the role of pretransplantation therapy for SCID patients, and the biology of post-HSCT immune reconstitution is under investigation.

Bronchoscopic instillation of surfactant in acute respiratory distress syndrome

Abnormalities of surfactant action in acute respiratory distress syndrome (ARDS) result in decreased lung compliance and significant hypoxemia. Several case reports and small studies suggest that there is an improvement in patients with ARDS following the administration of surfactant. However, there is no clear-cut ideal method for surfactant administration. The bronchoscopic administration of surfactant may represent an effective method of surfactant delivery in ARDS. Bronchoscopic instillation offers the theoretical advantages that the surfactant may be distributed directly to the desired regions of the lung, a more economical use of surfactant, and the opportunity to lavage leaked serum proteins prior to instillation. Surfactant has been administered in adults with success. We present a case of initial improvement in oxygenation index, ventilation index, and mechanical ventilatory support in a pediatric patient with ARDS following the bronchoscopic administration of surfactant.

Contour interaction in fovea and periphery

It has been known for some time that both foveal and peripheral visual acuity are higher for single letters than for letters in a row. Early work showed that this was due to the destructive interaction of adjacent contours (termed contour interaction). It has been assumed to have a neural basis, and a number of competing explanations have been advanced that implicate either high-level or low-level stages of visual processing. Our previous results for foveal vision suggested a much simpler explanation, one determined primarily by the physics of the stimulus rather than the physiology of the visual system. We show that, under conditions of contour interaction or crowding, the most relevant physical spatial-frequency band of the letter is displaced to higher spatial frequencies and that foveal vision tracks this change in spatial scale. In the periphery, however, beyond 5 degrees, the physical explanation is not sufficient. Here we show that there are genuine physiological lateral spatial interactions, which are due to changes in the spatial scale of analysis.

T cell depleted haploidentical bone marrow transplantation for the treatment of children with severe combined immunodeficiency

Severe combined immunodeficiency (SCID) is fatal in early childhood if unrecognized and if not treated. The aim was to determine the efficacy of T cell depleted bone marrow transplantation (TCD BMT) in the treatment of children with SCID. Eleven children diagnosed with SCID received histocompatible related donor bone marrow transplantation--HRD BMT (group I). Thirty seven children diagnosed with SCID who did not have histocompatible donors were treated with TCD haploidentical parental bone marrow transplantation (BMT) (group II). TCD was performed by in vitro soybean lectin agglutination followed by E-rosette depletion. Patients were longitudinally assessed for the presence and function of T and B lymphocytes. In group I all children survived. The mean age of children in this group at the time of HRD BMT was 15.4 months. All surviving patients normalized their specific T cell function. Two out of 11 require treatment with intravenous immunoglobulin i.v. Ig. In group II 17 out of 37 (46%) children survived. At the time of TCD BMT the mean age of survivors was 7.5 months, vs. 11.4 months in patients who died. Death was caused most commonly by opportunistic infections, Epstein-Barr virus induced lymphoproliferative disease (EBV-LPD), and graft versus host disease (GvHD). Seventeen out of 17 surviving patients recovered normal numbers of CD3+ cells and antigen specific T cell function. Five out of 17 never recovered their B cell function and require i.v. Ig injections. Early diagnosis, prevention or treatment of opportunistic infections, and enhancement of immune recovery will be necessary to improve survival in patients with SCID treated with TCD BMT.

The foveal 'crowding' effect: physics or physiology?

It has been known for some time that both foveal and peripheral visual acuity is higher for single letters than for letters in a row. Early work showed that this was due to the destructive interaction of adjacent contours (termed 'crowding' or contour interaction). It has been assumed to have a neural basis and a number of competing explanations have been advanced which implicate either high-level or low-level stages of visual processing. Our results suggest a much simpler explanation, one primarily determined by the physics of the stimulus rather than the physiology of the visual system. We show that, under conditions of contour interaction or 'crowding', the most relevant physical spatial frequency band of the letter is displaced to higher spatial frequencies and that foveal vision tracks this change in spatial scale.