Passive immunization against nicotine prevents nicotine alleviation of nicotine abstinence syndrome.

Passive immunization against nicotine interferes with its locomotor and pressor effects. The current study determined whether immunization could prevent another nicotine action: the reversal of nicotine abstinence syndrome. IgG containing 4.4-5.6% nicotine-specific antibody was isolated from rabbits immunized with 3'-amino-methyl-nicotine conjugated to a carrier protein. Twenty rats were rendered dependent by 7 days of subcutaneous infusion of 3.15 mg/kg/day nicotine (expressed as the base). Upon termination of nicotine infusion, each rat was injected intraperitoneally with 150 mg of IgG from normal serum (n=13) or from nicotine antiserum (n=7). Twenty-two and one-half hours later, all rats were observed over 15 min for baseline nicotine abstinence signs. Two and one-half hours after baseline observations, seven of the 13 rats pretreated with control IgG and all seven rats pretreated with nicotine-specific IgG were then challenged by 0.12 mg/kg (sc) nicotine. The remaining six rats pretreated with control IgG were challenged with saline alone. All rats were then observed again for abstinence signs. Nicotine injection caused significantly less reduction of abstinence signs in the immunized rats. The nicotine effect in immunized rats was comparable to the saline effect in nonimmunized rats. Immunization also significantly reduced free serum nicotine concentration and nicotine distribution to the brain. These results raise the possibility that immunization might prevent nicotine consumption from relieving the discomforts of smoking cessation.

[The maternal-neonatal characteristics of intrauterine growth retardation in a term pregnancy based on a national curve of intrauterine growth]. / Características materno-neonatales del retardo de crecimiento intrauterino en la gestación de término según curva nacional de crecimiento intrauterino.

Using a national curve of fetal growth development, clinical and laboratory characteristics of 100 term neonates small for dates and 130 term adequate for gestational age newborns are studied. A 91% of the small for dates were classified by the ponderal index as having symmetrical growth retardation. At the same time in the 230 mothers we look for clinical features that have been mentioned to produce intrauterine growth retardation. Results showed marked differences (with statistic significance) between both groups of women in relation to: nutritional factors, maternal height, labor activity and presence of oligoamnios. The newborns of both groups didn't show differences, with exception of congenital malformation. The incidence of the classical morbidity of small for dates (asphyxia, hypoglycemia, polycythemia) was no different in both groups. We believe the explanation is that the national curve is more exigent and neonates with higher weight fall under the 10th percentile. We think that in the study group a high percentage of small for dates, are constitutional small and not really growth retarded. We suggest the possibility to use the 5th percentile for better sensibility.