Vaccination in preterm and low birth weight infants in India

In India, the high neonatal and infant mortality rate is due in part to an increasing number of preterm and low birth weight (LBW) infants. Given the immaturity of immune system, these infants are at an increased risk of hospitalization and mortality from vaccine-preventable diseases (VPDs). In this narrative review, we screened the scientific literature for data on the risk of VPDs, vaccination delay and factors related to it in Indian preterm and LBW infants. Although routine childhood vaccinations are recommended regardless of gestational age or birth weight, vaccination is often delayed. It exposes these infants to a higher risk of infections, their associated complications, and death. After-birth complications, lack of awareness of recommendations, vaccine efficacy and effectiveness and concerns related to safety are some of the common barriers to vaccination. Awareness campaigns might help substantiate the need for (and value of) vaccination in preterm and LBW infants.

What is the context?

In India, the high neonatal mortality rate is due in part to an increasing number of pretern and low birth weight intants.

Affected infants have a poorly developed inmune system and are more susceptible to contracting vaccine-preventable diseases.

The Indian Academy of Pediatrics recommends vaccination according to the same schedule used for full term infants, following chronological (not gestational) age.

Delays in vaccinations increase the risk of preventable infections.

What is new?

Our review of the scientific literature shows that, in India:

infections have more serious conseuences in preterm and low birth weight infants

delays to vaccinate affected infants are common, mostly due to safety and effectiveness concerns from parents and healthcare pracitionrs.

What is the impact?

Improving mternal nutritional status and immunization, and perinatal care could help reduce the number of preterm and low birth weight infants.

Combining maternal immunization with vaccination of affected infants can confer safe and effective protection.

Awareness campaigns for parents and healthcare practitioners could address the issue of vaccination delay in pretern and low birth weight infants in India.

Lessons from ONTARGET

The recently published results of the ONTARGET trial shed a new light on the cardiovascular protection of patients at high risk of a cardiovascular event. Despite a number of trials looking at the efficacy of Angiotensin Converting Enzyme inhibitors (ACEis) or Angiotensin Receptor Blockers (ARBs) in the prevention of cardiovascular events in patients with specific high risk profiles, the question of the equivalence of ACEis and ARBs remained unanswered. The ONTARGET trial has shown that telmisartan 80 mg administered for a median duration of 4.5 years to patients at high risk of developing a major cardiovascular event, is equally effective to ramipril 10 mg. In addition, telmisartan was slightly better tolerated. The comparator ramipril has been chosen as it is currently the gold standard ACEi since the results of the HOPE study, in terms of the composite outcome of cardiovascular death, myocardial infarction and stroke. Moreover, ONTARGET is the first trial to test the hypothesis of superiority of adding an ARB (telmisartan 80 mg) to an ACEi (ramipril 10 mg) over the ACEi ramipril monotherapy in cardiovascular protection of the same broad range of high-risk patients. Surprisingly, despite a more pronounced blood pressure lowering, the combination of the two agents did not lead to an additional decrease in the number of events, but had significantly more side-effects compared to ramipril monotherapy. ONTARGET is a landmark study, performed according to the highest statistical and clinical standards, providing compelling evidence and clear answers to two important clinical questions.

Multidrug resistance modifies polyamines uptake in P388 murine lymphoma cells: experimental and modeling approach

Polyamines (putrescine, spermidine and spermine) are ubiquitous compounds, essential for cell growth. This paper compares the polyamine transport between sensitive P388 murine lymphoma cells and two multidrug resistant P388 sublines with the assistance of an experimental model. This new model allows the characterisation of the whole polyamines uptake and efflux. Three parameters are identified by the model: two rate constants (K+ for the uptake and K- for the efflux) which are considered as physical constants specific to the transport of one polyamine in one cell type, and Ci(o) which represents the initial intracellular concentration. This model well describes our experimental results of polyamine transport across the P388 cell plasma membrane. Multidrug resistant P388 cells exhibit spermine uptake significantly higher than that of sensitive cells when on the opposite, putrescine enters more rapidly into the sensitive P388 cells. In conclusion, comparison of polyamine transport between sensitive and multidrug resistant P388 phenotypes shows large and significant differences.

Evidence of difference between cytotoxicity, cell cycle and morphonuclear effects of polyamines on sensitive and multidrug resistant P388 cell lines

This paper reports studies on the influence of multidrug resistance (MDR) on the mechanism of polyamine toxicity. The effects of putrescine (PUT), spermidine (SPD) and spermine (SPM) on morphonuclear parameters and cell cycle were studied by means of digital cell image analysis. This reveals that only SPD and SPM condense chromatin inducing a strong decrease in the nuclear area and a cell-cycle arrest in phase G2 in P388/s and the two MDR sublines. A significant difference was observed between the sensitivity of the two phenotypes, which confirms results obtained by means of a microculture tetrazolium test which showed that SPD and SPM were highly, but very differently, cytotoxic on sensitive and MDR sublines, unlike PUT, which was not toxic. This encourages us to study more thoroughly possible differences in polyamine metabolic enzymes and uptake in these cells, to enable us to acquire a better understanding of the impact of MDR phenotype on the polyamine pathway.

Improved high-performance liquid chromatographic method for the determination of polyamines as their benzoylated derivatives: application to P388 cancer cells

A simple reversed-phase HPLC method was developed for the determination of eight polyamines or monoacetylpolyamines, as their benzoylated derivatives. Interfering products, inherent to the benzoyl chloride derivatization technique (benzoic acid, methyl benzoate and benzoic anhydride), were identified. A new derivatization procedure for their total elimination was developed without any loss of sensitivity and selectivity. Not only the HPLC method was validated, but also the choice of an internal standard was investigated. The results show that it is possible to use this HPLC assay to determine the polyamine content in P388 cancer cells. Furthermore, the method is now being used to evaluate the uptake of various polyamines by P388 cancer cells and by other cancer and parasitic cells.