Understanding healthcare providers' preferred attributes of pediatric pneumococcal conjugate vaccines in the United States

As higher-valent pneumococcal conjugate vaccines (PCVs) become available for pediatric populations in the US, it is important to understand healthcare provider (HCP) preferences for and acceptability of PCVs. US HCPs (pediatricians, family medicine physicians and advanced practitioners) completed an online, cross-sectional survey between March and April 2023. HCPs were eligible if they recommended or prescribed vaccines to children age <24 months, spent ≥25% of their time in direct patient care, and had ≥2 y of experience in their profession. The survey included a discrete choice experiment (DCE) in which HCPs selected preferred options from different hypothetical vaccine profiles with systematic variation in the levels of five attributes. Relative attribute importance was quantified. Among 548 HCP respondents, the median age was 43.2 y, and the majority were male (57.9%) and practiced in urban areas (69.7%). DCE results showed that attributes with the greatest impact on HCP decision-making were 1) immune response for the shared serotypes covered by PCV13 (31.4%), 2) percent of invasive pneumococcal disease (IPD) covered by vaccine serotypes (21.3%), 3) acute otitis media (AOM) label indication (20.3%), 4) effectiveness against serotype 3 (17.6%), and 5) number of serotypes in the vaccine (9.5%). Among US HCPs, the most important attribute of PCVs was comparability of immune response for PCV13 shared serotypes, while the number of serotypes was least important. Findings suggest new PCVs eliciting high immune responses for serotypes that contribute substantially to IPD burden and maintaining immunogenicity against serotypes in existing PCVs are preferred by HCPs.

Real-world prevalence of microsatellite instability testing and related status in women with advanced endometrial cancer in Europe

PURPOSE

To assess the real-world prevalence of microsatellite instability (MSI)/mismatch repair (MMR) testing and related tumor status in recurrent/advanced endometrial cancer patients in Europe.

METHODS

Data were from two multi-center, retrospective patient chart review studies conducted in the United Kingdom, Germany, Italy, France and Spain: The Endometrial Cancer Health Outcomes-Europe-First-Line (ECHO-EU-1L) study and the ECHO-EU-Second-Line (ECHO-EU-2L) study. ECHO-EU-1L included recurrent/advanced endometrial cancer patients who received first-line systemic therapy between 1/JUN/2016 and 31/MAR/2020 after recurrent/advanced diagnosis. ECHO-EU-2L included patients with recurrent/advanced endometrial cancer who progressed between 1/JUN/2016 and 30/JUN/2019 following prior first-line systemic therapy. Data collected included patient demographics, MSI/MMR tumor testing and results, and clinical/treatment characteristics.

RESULTS

ECHO-EU-1L included 242 first-line patients and ECHO-EU-2L included 475 s-line patients. For all patients, median age at recurrent/advanced diagnosis was 69 years, roughly half had endometrioid carcinoma histology and over 75% had Stage IIIB-IV disease at initial diagnosis. The prevalence of MSI/MMR testing in the first-line and second-line cohorts was similar (36.4 and 34.9%, respectively). Among those tested, a majority had non-MSI-high/MMR proficient tumors (80.7 and 74.7% among first- and second-line patients, respectively). About 15% had MSI-high/MMR deficient tumors in both cohorts, and a few patients had discordant results (3.4 and 10.8% among first- and second-line patients, respectively).

CONCLUSION

Prior to the approvals of biomarker-directed therapies for recurrent/advanced endometrial cancer patients in Europe, there were low MSI/MMR testing rates for these patients of just over one-third. Given the availability of biomarker-directed therapies, increased MSI/MMR testing may help inform treatment decisions for recurrent/advanced endometrial cancer patients in Europe.

583. Preferences and Attitudes of Healthcare Providers towards Pneumococcal Conjugate Vaccines (PCVs) for Children Ages Two and Under in the United States (US)

Background

As higher-valent PCVs are currently in late-stage clinical development for pediatric use, it is important to understand how healthcare providers (HCPs) evaluate vaccine attributes when making recommendations for newer PCVs. The Advisory Committee on Immunization Practices considers feasibility and stakeholder acceptability in making vaccine recommendations; this study examined HCP preferences and attitudes towards new, higher-valent PCVs in children in the US.

Methods

Semi-structured qualitative interviews were conducted with 13 HCPs (6 pediatricians, 3 family practitioners, 3 nurse practitioners, and 1 physician assistant). US HCPs were recruited from an online panel and were eligible if they recommended or prescribed vaccines to children ≤ 2 years and spent ≥ 2 days a week providing care to pediatric patients. Providers were asked to rate a list of PCV attributes (generated by literature search) by their importance in influencing their PCV choices (1, not important; 10, most important). Interviews were recorded, transcribed, and analyzed.

Results

Among HCPs (mean age=49 years; 62% women; 38% urban, 38% suburban; mean years in practice=18 years), three main themes emerged: 1) Preferred attributes: The three most important PCV characteristics that affect HCPs’ recommendations are effectiveness against serotype 3 (rated 9.1), percent serotype coverage for invasive pneumococcal disease (IPD) (rated 8.9), and immune response for the shared PCV13 serotypes (rated 8.2). 2) PCV choice: Most respondents are interested in having more PCV options, particularly options with higher efficacy or broader serotype coverage. 3) Immunogenicity vs serotype coverage: Between a higher immune response to certain serotypes and broader serotype coverage, 46% of HCPs prefer PCVs that elicit a higher immune response but narrower coverage, 31% prefer a PCV with broader serotype coverage, and 23% require more data before making a determination.

Conclusion

Both immune response and breadth of serotype coverage may influence HCPs decisions when recommending new PCVs. Additional analyses and interviews are underway to validate these findings and further explore other factors that may influence their preferences for recommending PCVs.

Disclosures

Salini Mohanty, DrPH, MPH, Merck & Co., Inc.: Employee Jui-Hua Tsai, MD, MHS, OPEN Health: Employee of OPEN Health, which received funding from Merck & Co., Inc. to conduct this research Ning Ning, PhD, MS, Open Health: I am an employee of OPEN Health, which received funding from Merck Ana Pena-Molina, MPH, OPEN Health: I am an employee of OPEN Health, which received funding from Merck Rishi P. Verma, MPH, OPEN Health: I am an employee of OPEN Health, which received funding from Merck Marieke Heisen, PhD, MSc, OPEN Health: I am an employee of OPEN Health, which received funding from Merck Jessica Weaver, PhD, MPH, Merck & Co., Inc.: Employee Kristen A. Feemster, MD, MPH, MSHPR, FAAP, Merck & Co., Inc.: Employee Thomas Weiss, DrPH, MPH, Merck & Co., Inc.: Employee Jordana Schmier, MA, OPEN Health: I am an employee of OPEN Health, which received funding from Merck.

Treatment patterns and outcomes among patients with recurrent or advanced endometrial cancer in Europe: Endometrial Cancer Health Outcomes Europe (ECHO EU) Study

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Background: Until recently, recurrent or advanced endometrial cancer (aEC) patients in Europe had limited treatment options, with no consensus on standard of care in such settings. Approval of novel targeted therapies in 2021 are changing the treatment landscape. However, there is little real-world evidence among aEC patients in Europe. The objective of our study was to evaluate real-world treatment patterns and clinical outcomes in aEC patients who progressed following prior systemic therapy (FPST) in clinical practice in Europe. Methods: The ECHO-EU is a multicenter, retrospective chart review study in United Kingdom (UK), Germany (GE), Italy (IT) and Spain (SP). Adult women diagnosed with aEC who received at least one prior systemic therapy and progressed between July 1, 2016 – June 30, 2019, were included. De-identified patient data extracted by treating oncologists from patients’ medical records included patient demographics, clinical and treatment characteristics, and clinical outcomes. Kaplan-Meier analyses were performed to estimate real-world overall survival (OS). Results: A total of 379 (UK=101, GE=88, IT=100, SP=90) eligible aEC patients were included in the analysis. At aEC diagnosis, patients’ median age was 69 years, 97% were White/Caucasian and most prevalent histology was endometrioid carcinoma (58%). Molecular characterization of tumors including microsatellite instability/mismatch repair (MSI/MMR) status was performed in only 37% of patients. Metastases were observed in 56% of the patients at diagnosis. Median duration of follow up from aEC diagnosis was 24 months. The majority (95%) of patients initiated 1st line with chemotherapy (most commonly with platinum chemotherapy and paclitaxel). As 2nd line therapy, 81% received mono or combination chemotherapy, and 19% received hormonal therapy. Doxorubicin was the most frequently used agent (45%) in 2nd line, and 16% of patients were re-treated with platinum therapy. At last follow-up, the majority (90%) of patients discontinued 2nd line treatment, mostly due to disease progression (54%). Median duration of 2nd line therapy was 5 months (95% Confidence Interval [CI]: 4-5). Median OS from initiation of 2nd line therapy was 11 months (95% CI: 10-13). Estimated probability of OS from initiation of 2nd line therapy at 6, 12, and 24 months were 70%, 45%, and 30%, respectively. Conclusions: Our study finds thatin Europe prior to mid-2019, available treatment options were sub-optimal for aEC patients FPST, leading to poor prognosis. The utilization of MSI/MMR testing for molecular characterization of tumors was low and needs to increase. There was a significant unmet need for novel therapies that improve clinical outcomes in this patient population. Future studies evaluating treatment patterns and clinical outcomes with more recently approved treatments are warranted.

Predictability of transcutaneous bilirubinometry in late preterm and term infants at risk for pathological hyperbilirubinemia

BACKGROUND

The aim was to assess the predictability of transcutaneous bilirubinometry in late preterm and term neonates at risk for pathological hyperbilirubinemia, and to identify the neonatal population in which transcutaneous bilirubin most accurately predicts serum bilirubin level (SB, mg/dl).

METHODS

The correlations between transcutaneous bilirubin (TCB, mg/dl) and SB in different neonatal population subsets; and between ΔTSB (TCB-SB) and relevant neonatal variables and clinical groups were analyzed.

RESULTS

TCB correlated with SB (r = 0.82, p < 0.05) in the cohort (n = 350) and in population subsets (r = 0.81-0.9, p < 0.001). Black infants with gestational age (GA) >35 weeks and chronological age (CA) >3 days recorded strongest correlation (r = 0.9, p < 0.001) followed by Blacks, and non-Black infants with CA >3 days and GA >35 weeks. ΔTSB was positive in Blacks, and in infants with CA <3 days, or with no phototherapy. ΔTSB was negative in non-Blacks, in infants with positive direct Coombs test (DC+) or those receiving phototherapy. Black race [beta (SE) = 1.3(0.33), p < 0.001] had positive, while CA [beta (SE) =-1.74 (0.36), p < 0.001], DC + status [beta (SE) =-0.72 (0.25), p = 0.004] and receipt of phototherapy [beta (SE) =-0.84 (0.21), p < 0.001] each had negative correlation with ΔTSB. ΔTSB for Blacks was >Whites, Hispanics and Asians.

CONCLUSION

SB is best predicted by TCB in Black infants with CA over 3 days and GA over 35 weeks. Variability in SB estimation by TCB is race, CA and immune mediated hemolysis specific.

Screening difficult-to-reach populations for tuberculosis using a mobile medical unit, Punjab India

BACKGROUND

In India, the National Health Mission has provided one mobile medical unit (MMU) per district in the state of Punjab to provide primary health care services for difficult-to-reach populations.

OBJECTIVES

To determine the number of patients with presumptive tuberculosis (TB) and the number of TB cases detected and treated among patients who used the MMU services from May to December 2012 in Mohali district, Punjab, India.

METHODS

A cross-sectional study was conducted and registers of the out-patient, laboratory, radiology, and TB departments of the MMU were reviewed to determine the number of persons presumed to have TB and the number of persons diagnosed with TB.

RESULTS

Of 8346 patients who attended the MMUs, 663 (8%) had symptoms suggestive of TB. Among those with TB symptoms, 540 (81%) were evaluated for pulmonary TB using sputum examination or chest X-ray. In total, 58 (11%) patients had clinical or laboratory evidence of pulmonary TB, of whom 21 (36%) started anti-tuberculosis treatment.

CONCLUSION

As MMUs are an integral part of the general public health system, these units have the potential to detect TB cases among difficult-to-reach populations. Additional research is required to optimise the diagnosis of TB at MMUs and to increase rates of TB treatment initiation.

An in silico expert system for the identification of eye irritants

This report describes development of an in silico, expert rule-based method for the classification of chemicals into irritants or non-irritants to eye, as defined by the Draize test. This method was developed to screen data-poor cosmetic ingredient chemicals for eye irritancy potential, which is based upon exclusion rules of five physicochemical properties - molecular weight (MW), hydrophobicity (log P), number of hydrogen bond donors (HBD), number of hydrogen bond acceptors (HBA) and polarizability (Pol). These rules were developed using the ADMET Predictor software and a dataset of 917 eye irritant chemicals. The dataset was divided into 826 (90%) chemicals used for training set and 91 (10%) chemicals used for external validation set (every 10th chemical sorted by molecular weight). The sensitivity of these rules for the training and validation sets was 72.3% and 71.4%, respectively. These rules were also validated for their specificity using an external validation set of 2011 non-irritant chemicals to the eye. The specificity for this validation set was revealed as 77.3%. This method facilitates rapid screening and prioritization of data poor chemicals that are unlikely to be tested for eye irritancy in the Draize test.

Risk factors and clinical outcomes of pulmonary interstitial emphysema in extremely low birth weight infants

OBJECTIVE

We studied the ante- and postnatal risk factors and clinical outcomes associated with pulmonary interstitial emphysema (PIE) in extremely low birth weight infants (ELBW, <1000 g at birth) in the present era of tocolytics, antenatal steroid and postnatal surfactant administration.

STUDY DESIGN

This was a retrospective case-controlled study of all ELBW admitted consecutively during a designated study-period in a level III nursery. Data were analyzed by performing univariate and multivariate analysis as applicable.

RESULTS

Infants with PIE had lower 1 and 5 min Apgar scores (P=0.04 and 0.003 respectively), increased surfactant utilization (P=0.004), higher maximum inspired oxygen concentration (P=0.04) and mean airway pressure administration (P=0.02) during the first week of life, and increased neonatal mortality (P=0.01). They received higher antenatal doses of magnesium sulfate (MgSO(4)) (P=0.02). 56% of infants with PIE were exposed to more than 10 g of MgSO(4) (Mg10), compared to 15% in non-PIE group (P=0.01). The multivariate logistic regression analysis including significant co-variates revealed an independent association between Mg10 and PIE (P=0.01, Odds ratio 19.8, 95% CI 1.5-263).

CONCLUSION

Pulmonary interstitial emphysema is associated with increased mortality in ELBW infants. Mg10 is an independent risk factor for PIE in this population.

Inhibition of neutrophil elastase and thrombin activity by caffeic acid esters

Natural and synthetic caffeic acid esters were assayed for their enzymatic activity versus neutrophil elastase (EC 3.4.21.37) and thrombin (EC 3.4.21.5). Lipophilic caffeic acid esters inhibited neutrophil elastase activity and the inhibition rate was enhanced with increasing length of the aliphatic chain of the alcohol component. The geometry of the chain seems to be more important than the number of carbon atoms. The most inhibitory compound was n-octylcaffeic acid ester with an IC50 value of 1.0 microM. Thrombin activity was only weakly inhibited by the caffeic acid esters thus demonstrating a specificity for neutrophil elastase. Because of its critical role in inflammatory processes, inhibition of neutrophil elastase by caffeic acid esters might be of importance in the treatment of inflammation.

QSAR: then and now

In this review, the evolution of QSAR is traced from the insightful observations of Crum-Brown and Frazier to Hammett's critical equations and finally Hansch's seminal contributions on hydrophobicity and modelling of biological activity based on extrathermodynamic principles. Today's QSAR models can stand alone, augment other graphical approaches or be examined in tandem with equations of a similar mechanistic genre to truly reveal the power of the paradigm. This review will focus on the three standard classifications routinely used in QSAR analysis electronic, hydrophobic, and steric, as well as topological indices. Electronic parameters will focus on Hammett sigma constants and their numerous variations. Dipole moments, hydrogen bond descriptors and quantum chemical indices as well as applications of their utilization will be described. The hydrophobicity parameter will be examined by tracing its early history, its operational definition and its determination by either experimental methods or computational calculations. Steric parameters, which run the gamut from size to shape, will be described by Taft's, Hancock's, Charton's, Fujita's, Verloop's and Simon's contributions. Topological effects, delineated by connectivity indices, kappa shape and electrotopological indices of Kier and Hall are also described. Examples of QSAR models incorporating most of these parameters are reviewed. In cases where the 95% confidence intervals of variables are available, they are listed in parentheses. A brief Comparative QSAR analysis of non-nucleoside reverse transcriptase inhibitors (NNRTI's) is outlined and various models obtained by different groups examining 4, 5, 6, 7-tetrahydro-5-methylimidazo [4, 5,1-j,k][1,4] benzodiazepin-2(1H)-ones (TIBO) and 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine (HEPT) derivatives are compared for mechanistic insight that could be useful in the process of inhibitor design.

Toxicology of benzyl alcohols: a QSAR analysis

There is an evidence that benzyl alcohols may exhibit toxicity via a radical mechanism. To test this possibility, we studied the toxicity of para substituted benzyl alcohols on rapidly dividing cancer cells (L1210 leukemia). This system has previously found utility in studying the apparent radical toxicity of a variety of phenols. However, no evidence could be found for an electronic effect and the cellular toxicity was associated primarily with hydrophobicity. Comparison of this quantitative structure-activity relationships (QSAR) with others for the reactions of benzyl alcohols in diverse systems provides insight into mechanisms of action. A QSAR for the interaction of benzyl alcohols with protozoa yields an equation that is dependent on both hydrophobicity and acidity of the OH group versus a mixture of bacteria and fungi, the critical dependence on hydrophobicity prevails with a small dependence on a resonance-stabilized, radical mediated electronic effect. The chloramphenicols provide an instructive example, where the radical mediated electronic effect overshadows the hydrophobic contribution to bacterial toxicity. These various QSAR for benzyl alcohols indicate that mechanisms of growth inhibition in vitro vary depending on cell/organism type, the strength of the bond and lability of the hydrogen, and the strength of the initiating radical reagent.

Early neonatal urinary tract infection: a case report and review

We report the earliest case of urinary tract infection (UTI) so far described in term uncomplicated newborn infants. The unusual features of this case included early massive hematuria as the only presenting symptom and a host with no risk factors for either sepsis or localization of infection in the genitourinary tract. Reports of urinary analysis, urine cultures, renal ultrasound, and renal scan established the diagnosis of UTI. Massive hematuria in this case was probably precipitated by mild renal venous thrombosis. Ampicillin-resistant Escherichia coli was cultured from the urine, which responded promptly to appropriate treatment. A urine culture was done because of the predominantly urinary signs and symptoms. Although urine culture analysis is not routinely performed for the evaluation of possible sepsis before 72 hours of age, this investigation may be important in critically ill neonates who present with predominantly genitourinary signs and symptoms.

Vitamin A deficiency and severe bronchopulmonary dysplasia in very low birthweight infants

Preterm infants often have abnormally low serum vitamin A concentrations. Persistence of vitamin A deficiency for a prolonged postnatal period may contribute to the development of bronchopulmonary dysplasia. We retrospectively analyzed data from 22 infants with birthweight < or = 1250 g who had hyaline membrane disease requiring mechanical ventilation with oxygen and in whom serum vitamin A concentrations had been measured at the onset of enteral feeding and every 2 weeks thereafter. Thirteen infants (low serum vitamin A group) had one or more serum vitamin A concentrations < or = 11 mcg/dL at > 10 days of age. In 9 infants (higher serum vitamin A group) all serum vitamin A concentrations were > 11 mcg/dL at > 10 days of age. Mean birthweight, mean gestational age, sex, race, incidence of antenatal maternal glucocorticoid treatment and ventilatory support on the first day of life were similar for the two groups. Severe bronchopulmonary dysplasia was as defined as characteristic radiographic changes and either discharge from the hospital with supplemental oxygen or death from respiratory failure at > 28 days of age following mechanical ventilation with oxygen since birth. The incidence of severe bronchopulmonary dysplasia was significantly higher in the low serum vitamin A group (11/13, 3 deaths vs. 1/9, no deaths; p=0.001). The incidence of pulmonary air leak, the number of ventilator days, the number of days of postnatal glucocorticoid treatment for chronic lung disease, the number of episodes of suspected sepsis and the number of days of antibiotic treatment also were higher in the low serum vitamin A group. Low serum vitamin A group infants were older at the onset of enteral feeding (21 days vs. 8 days; p = 0.001) and during feeding their average daily enteral intake of vitamin A was lower (713 IU vs. 1255 IU; p = 0.001) when compared with infants in the higher serum vitamin A group. Our retrospective analysis of data from these infants confirms earlier reports from other workers that persistent marked vitamin A deficiency in very low birthweight infants is associated with a high incidence of severe bronchopulmonary dysplasia, delayed onset of enteral feeding and low enteral intake of vitamin A.

Respiratory distress syndrome of the newborn infant

Pulmonary immaturity, including deficiency in the surfactant system, incomplete structural/functional development of lungs and high chest wall compliance contribute to the pathogenesis of respiratory distress syndrome (RDS). Pulmonary edema and overperfusion, resulting from a patent ductus arteriosus, may further worsen the respiratory failure, and aggravate the surfactant deficiency. Infants born prematurely present with respiratory distress within the first few minutes of life. This quickly becomes life-threatening, and may result in death from severe respiratory failure if appropriate respiratory and general supportive therapy are not immediately instituted. The oxygenation deficit in RDS is secondary to V/Q mismatch and right-left shunting of blood via pulmonary and extrapulmonary routes. Hypoxemia induced pulmonary vasoconstriction further contributes to V/Q mismatch and R-L shunting. Hypoventilation in RDS is due to decreased tidal volume, increased dead space ventilation, and finally, decreased minute ventilation. Characteristically, pulmonary compliance, both static and dynamic, are greatly reduced resulting in a high work of breathing, whereas airway resistance is normal or only slightly increased. This combination of abnormal pulmonary mechanics results in lower respiratory time constant in respiratory units, and helps in achieving ventilation and oxygenation by using low inspiratory time in the ventilator. Management of RDS starts with prenatal identification of the risk, prolongation of pregnancy by tocolysis and prenatal administration of pharmacological agents, like betamethasone. These agents increase the pulmonary gas exchange surface area and induce endogenous pulmonary surfactant in the fetus. Advances in ventilatory and general management techniques have strikingly improved the outcome and prognosis of children suffering from RDS since the 1960s. Recent advancements in the prevention and treatment of RDS, e.g., acceleration of lung development by prenatal pharmacological manipulations and postnatal provision of exogenous surfactant, have significantly contributed to the decrease in mortality from RDS. Pharmacological induction of lung maturation by drugs in combination, and improved technology in lung ventilation are expected to further improve the course and outcome of the disease in future.

Body electrolytes in bronchopulmonary dysplasia and the effects of diuretic therapy

Body electrolytes and their regulatory hormones were studied in preterm infants who suffered from bronchopulmonary dysplasia under two groups: those who were not treated with diuretics (Group II), and those who were treated with diuretics (Group III). The values were compared with a group of matched healthy controls (Group I). Lower serum Na levels, a need of higher Na intake, and higher urinary Na concentrations and urinary specific gravity were found in Group II infants. FeNa was normal and the urinary flow rate was lower than the controls. These data suggest an inability of these infants to dilute urine. Group III infants who were treated with diuretics showed higher serum Na levels and lower urinary specific gravity than Group II infants. These values, as well as water and Na intake/output ratios, were all similar to the control values. Serum aldosterone level was highest in Group II but did not reach significance. Intracellular K concentration was not different between the groups indicating an optimum total body K balance. A significant negative correlation between serum Na and aldosterone levels was found in Group II infants, which was not noted in the controls. Significant correlations were also found between FeNa and plasma aldosterone level in the BPD groups, unlike the controls. The control group of infants showed significant positive correlation between Na balance and serum Na levels. Our results suggest that inability to dilute urine appropriately might be the reason for the BPD patients to retain body water. Water restriction and diuretic therapy therefore are reasonable therapeutic approaches in such cases.

Maturational response of colonic and renal Na+,K(+)-ATPase activity to K+ load and betamethasone in preterm rats

Preterm human infants demonstrate high fecal K+/Na+ ratio that is inversely related to maturation. Renal and colonic basolateral membrane-located Na+,K(+)-adenosine triphosphatase (Na+,K(+)-ATPase) governs K+ excretion and is enhanced by both steroid administration and K+ loading. However, the response of premature kidney or colon to these stimuli is not well studied. We measured basal as well as stimulated levels of renal and colonic Na+,K(+)-ATPase activity in response to betamethasone and K+ load given separately and betamethasone given after K+ load in premature, mature, and 4-day-old Sprague-Dawley rats. Although preterm rats showed a higher basal level in the kidneys (p < 0.004), an increase in enzyme activity in response to the stimuli was achieved only in the colon (p < 0.001 for betamethasone, p < 0.0001 for K+ load, and p < 0.0007 for the combination). At term and at 4 days of postnatal age, however, the kidneys showed much higher levels than the colon in response to stimuli (p < 0.0001 for all) except for betamethasone at term. The response of colonic tissue of preterm and term rats to betamethasone given 4 days after a K+ load was less marked than response to betamethasone or K+ load given separately (p < 0.001). The stimulated levels achieved in the preterm colon were higher than the basal preterm renal values (p < 0.001). The tissue K+ content increased in response to K+ load in only the preterm colon (p < 0.05). We have demonstrated a tissue specificity in the development of Na+,K(+)-ATPase activity in K+ excretory organs of rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Fecal sodium and potassium losses in low birth weight infants

We measured 24-hour fecal losses of sodium (Na) and potassium (K) in immediate post natal period of preterm neonates to determine the role of this route in the electrolyte imbalances seen in such infants. The values from preterm infants were compared to a group of age matched term infants. Eleven studies were done on unfed extremely low birth weight infants (group I, birth weight < 1200 gms), seven on fed preterm infants (group II, birth weight 1201-2500 gms) and nine on fed term infants (group III, birth weight 2501-4000 gms). Measured and derived variables compared between the groups were 24 hour fecal volume, total fecal electrolyte contents, Na or K lost per kg of body weight and per gm. of stool and Na or K losses as percent of intake. Although 24 hour fecal volume was lowest in group I, none of the variables related to Na differed between groups I and II whereas all of them were significantly lower in group I when compared with group III. Groups II and III differed only in terms of Na loss/gm stool which was lower in the previous group. Conversely K loss/gm of stool was significantly higher in group I when compared with both groups II and III and the only variable that differed between groups II and III was a higher fecal K content as fraction of intake. Fecal K/Na ratio was highest in group I, and decreased progressively with advancing gestational age, whereas creatinine clearance was lowest in group I and increased along with gestational age.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial calcification in an extremely low birth weight infant with chronic renal failure and secondary hyperparathyroidism

Myocardial calcification has been rarely described in premature infants after myocardial infarction and myocarditis with coxsackievirus B1. In adults and older children, metastatic myocardial calcification has been reported in chronic renal failure. We report a case of myocardial calcification in a 680-gm preterm infant after a prolonged course of renal failure complicated by secondary hyperparathyroidism. Subclinical myocardial injury was evidenced by a high serum creatine phosphokinase MB band concentration, which probably provided a susceptible substrate for the deposition of calcium crystals, because the multiplication product of serum calcium and inorganic phosphorus levels transiently exceeded 75 mg x mg/100 ml, indicating serum saturation during the course of secondary hyperparathyroidism. We report this case as an unusual complication of renal immaturity in extremely low birth weight infants and an indication of a relatively intact parathyroid glandular function in them. Hypoxia, myocardial dysfunction, and renal failure are common complications in such infants, and in the presence of renal failure, the serum levels of calcium and inorganic phosphorus should be maintained below the pathologic level to avoid ectopic calcification of the tissues, including the myocardium.

The allelic relationship of genes giving resistance to mungbean yellow mosaic virus in blackgram

The allelic relationship of resistance genes for MYMV was studied in blackgram (V. mungo (L.) Hepper). The resistant donors to MYMV - 'Pant U84' and 'UPU 2', and their F1, F2 and F3 generations - were inoculated artificially using an insect vector, whitefly (Bemisia tabaci Genn.). The two recessive genes previously reported for resistance were found to be the same in both donors.