In infants

C-6 Hydroyylation. This biotransformation is more predominant in infants than in adults, and can prevent other metabohc transformations. 

Glucuronidation. Complexation of the steroid to glucuronic acid, most predominantiy via the C-3 hydroxyl, leads to a considerable portion of the excreted metabohtes of ah. glucocorticoids. In infants, sulfurylation (formation of a sulfate ester) is also predominant (16). 

Of the water-soluble vitamins, intakes of nicotinic acid [59-67-6] on the order of 10 to 30 times the recommended daily allowance (RE)A) have been shown to cause flushing, headache, nausea, and moderate lowering of semm cholesterol with concurrent increases in semm glucose. Toxic levels of foHc acid [59-30-3] are ca 20 mg/d in infants, and probably approach 400 mg/d in adults. The body seems able to tolerate very large intakes of ascorbic acid [50-81-7] (vitamin C) without iH effect, but levels in excess of 9 g/d have been reported to cause increases in urinary oxaHc acid excretion. Urinary and blood uric acid also rise as a result of high intakes of ascorbic acid, and these factors may increase the tendency for formation of kidney or bladder stones. AH other water-soluble vitamins possess an even wider margin of safety and present no practical problem (82). 

Diagnosis and alleviation of the cause, if possible, is of primary importance. Often, however, this is not possible and therapy is used to alleviate the inconvenience and pain of diarrhea. These compounds usually only mask the underlying factors producing the problem. Diarrhea may cause significant dehydration and loss of electrolytes and is a particularly serious problem in infants. Antidiarrheals do not usually prevent the loss of fluids and electrolytes into the large bowel and, although these may prevent frequent defecation, often the serious imbalance of body electrolytes and fluids is not significantly affected. 

Primary immunodeficiencies are uncommon, and may occur in 1 in 10,000 individuals (6). Many primary immunodeficiencies are hereditary and congenital, and first appear in infants and children. Primary immunodeficiencies are classified into four main groups (7) relating to the lymphocytes (B-ceUs, T-ceUs, or both), phagocytes, or the complement cascade (8). Primary deficiency diseases result from B-ceU defects in 50% of cases, from T-ceU defects in ca 10%, and from combined B- and T-ceU defects in ca 20%. Phagocytic disorders account for 18% and complement defects occur in 2% of all cases. 

Rotavirus. Rotavims causes infant diarrhea, a disease which has major socio-economic impact. In developing countries it is the major cause of death in infants worldwide, causing up to 870,000 deaths per year. In the United States, diarrhea is stiU a primary cause of physician visits and hospitalization, although the mortaUty rate is relatively low. Studies have estimated a substantial cost benefit for a vaccination program in the United States (67—69). Two membrane proteins (VP4 and VP7) of the vims have been identified as protective epitopes and most vaccine development programs are based on these two proteins as antigens. Both Hve attenuated vaccines and subunit vaccines are being developed (68). 

Respiratory Syncytial Virus. Respiratory syncytial vims (RSV) causes severe lower respiratory tract disease in infants. It is the major cause of hospitalization in the United States (- 90,000 events/yr) and it has a high mortaUty rate in neonates and other high risk populations, such as the geriatric population (51). Development of an RSV vaccine has always been a major priority, however, earlier attempts have mostiy failed (70). 

Parainfluenza. Parainfluenza vimses (PIV) also causes viral pneumonia in infants. It is similar to RSV, therefore similar approaches are being used for developing a vaccine. A five attenuated PIV-3 vaccine has been in clinical trial (74). 

Table 5 Isoflavone levels in infants fed various forms of milk or milk substitute " ...

Nitrate is not a new problem. Excessive concentrations were recorded in many domestic wells in a survey conducted 100 years ago. What is new is the public concern about nitrate. This arises from two medical conditions that have been linked to nitrate methaemoglobinaemia ( bine-baby syndrome ) in infants, and stomach cancer in adults. Both are serious conditions, so we need to examine possible links carefully, but we need to note that these conditions are not caused by nitrate but by the nitrite to which it may be reduced. Nitrate itself is harmless and is most notable from a medical standpoint as a treatment for phosphatic kidney stones. 

Nitrate (measured as Nitrogen) 10 10 "Blue baby syndrome" in infants under six months -life threatening without immediate medical attention. Symptoms Infant looks blue and has shortness of breath. Runoff from fertilizer use leaching from septic tanks, sewage erosion of natural deposits... 

Phenylpyruvic acid can cause mental retardation in infants who are deficient in the enzymes necessary to convert L-phenylalanine to L-tyrosine. This disorder is called phenylketonuria, or PKU disease. PKU disease can be detected by a simple test routinely administered to newborns. It cannot be cured, but is controlled by restricting the dietary intake of L-phenylalanine. In practice this means avoiding foods such as meat that are rich in L-phenylalanine. 

S100B Sensitive marker of hypoxic brain damage in infants and children undergoing open-heart surgery... 

A seizure is an abnormal behavioral (often motoric) activity caused by abnormal electrical activity of the brain. Seizures can be the symptom of a chronic neurological malfunction, i.e. epilepsy, or can appear as single events, e.g. during fever in infants. 

As the above mentioned studies with high supplementation dosages exemplarily show, there is no known toxicity for phylloquinone (vitamin Kl), although allergic reactions are possible. This is NOT true for menadione (vitamin K3) that can interfere with glutathione, a natural antioxidant, resulting in oxidative stress and cell membrane damage. Injections of menadione in infants led to jaundice and hemolytic anemia and therefore should not be used for the treatment of vitamin K deficiency. 

Rl 0AVIRIN. This drug can cause worsening of the respiratory status. Sudden deterioration of respiratory status can occur in infants receiving ribavirin. It is important to monitor respiratory function closely throughout therapy. The nurse should immediately report any worsening of respiratory function to the primary health care provider. 

Loop diuretics are contraindicated in patients with known hypersensitivity to the loop diuretics or to the sulfonamides, severe electrolyte imbalances, hepatic coma, or anuria, and in infants (ethacrynic acid). 

Haemophilus influenzae type b (Hib) conjugate vaccine. Three Hib conjugate vaccines are licensed for infant use. If PRP-OMP (PedvaxHIB or ComVax) is administered at ages 2 and 4 months, a dose at age 6 months is not required. DTaP/Hib combination products should not be used for primary immunization in infants at ages 2, 4 or 6 months, but can be used as boosters following any Hib vaccine. 

The keratolytics are contraindicated in patients with known hypersensitivity to the drugs and for use on moles, birthmarks, or warts with hair growing from them, on genital or facial warts, on warts on mucous membranes, or on infected skin. Prolonged use of the keratolytics in infants or patients with diabetes or impaired circulation is contraindicated. Salicylic acid... 

Once widely used in over-the-counter products, hexachlorophene is now available by prescription only, due to incidents of overdose in infants in France during the 1970s. It has been largely replaced by the related compound triclosan. 

Short-chain acyl-CoA dehydrogenase (SCAD) deficiency has been recorded in only a few patients and these show wide variation in clinical presentation. The defect has been seen in infants with a syndrome of psychomotor retardation and failure to thrive. These infants showed abnormal organic aciduria, and drastically decreased SCAD activity was demonstrable in cultured fibroblasts. Muscle symptoms were only part of a wider syndrome in all infants and children so far reported to have SCAD deficiency, but were the sole presenting feature in two adult patients, in whom lipid storage was demonstrable in skeletal muscle. The gene encoding for human SCAD has been mapped to chromosome 12. 

Although NOT is not usually thought of as a "toxic" chemical, it does cause several health problems including methemoglobinemia in infants (blue-baby syndrome) and may also be linked to stomach cancer. Agricultural runoff can lead to significant, potentially harmful, concentrations of NOT in ground or surface water. 

Sex and age differences in stable isotopes of nitrogen and carbon are not pronounced. There is no evidence that males and females were eating different foods and the only evidence for age differences, higher 8 N in infants, has been explained by the trophic level shift during the time the infant derives most of its protein from, breast milk. The small amount of variation in both and 5 N values supports the historical sources, which indicate that while food was plentiful, the diet was rather monotonous. 

An FDA study of pesticide residues in infant and adult foods eaten by infants/children for the period 1985-1991 reported results for methyl parathion as total parathion (Y ess et al. 1993). Of the 2,464 apples analyzed, total parathion was detected in 158 samples at a maximum of 1.3 ppm. Of the 862 oranges analyzed, total parathion was detected in 25 samples at a maximum of 1.4 ppm. Of the 571 pears analyzed, total parathion was detected in 8 samples at a maximum of 0.12 ppm. 

Schilter B, Renwick AG, Huggett AC. 1996. Limits for pesticide residues in infant foods A safety-based proposal. Regul Toxicol Pharmacol 24 126-140. 

Tikhonova ON, Obert AS, Vinokurov YI. 1995. [Influence of environmental factors upon the frequency and severity of intestinal dysbiosis in infants] (Russian). Pediatriya 5 61-62. 

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