High prevalence of lactase non-persistence among indigenous nomadic Nenets, north-west Russia.

Objectives: The frequency of adult-type hypolactasia (lactase non-persistence) varies widely among different ethnic groups. The cultural historical hypothesis assumes a link between the occurrence of hypolactasia and the distribution of dairy farming. The nomadic Nenets have been reindeer herders for generations and have therefore not consumed any dairy products.

Lactase non-persistent genotype influences milk consumption and gastrointestinal symptoms in Northern Russians.

Background: Milk is an important source of nutrients. The consumption of milk, however, may cause abdominal complaints in lactose intolerant individuals. The frequency of -13910C/C genotype is known to be high among Northern Russians, exceeding the prevalence in northern Europe.

The -13914G>A variant upstream of the lactase gene (LCT) is associated with lactase persistence/non-persistence.

Background: Adult-type hypolactasia (lactase non-persistence) is a common cause of gastrointestinal symptoms. Several DNA sequence variants have been identified for the lactase-persistence/non-persistence (LP/LNP), the most common being the C to T residing -13910 bp upstream of the lactase gene (LCT). We have analysed sequence variants of LP/LNP in subjects originating from Northern Russia.

Prevalence of lactase persistent/non-persistent genotypes and milk consumption in a young population in north-west Russia.

Aim: To estimate the prevalence of the lactase non-persistent genotype (C/C-13910) in a northern Russian population in accordance with ethnicity, and to evaluate self-reported milk consumption depending on lactase activity.

Methods: Blood samples for genotyping lactase activity, defining the C/T-13910 variant by polymerase chain reaction, and direct sequencing were taken from 231 medical students of Russian origin aged 17-26 years. We analyzed milk product consumption by questionnaire which was specially designed for the estimation of milk consumption and abdominal complaints.

Use of quality improvement methods in Finnish health centres in 1998 and 2003.

Objective: To evaluate how widely quality improvement methods are used in Finnish primary health centres and how the use has changed over five years.

Design: Two national cross-sectional postal enquiries.

Setting And Subjects: The questionnaire in 1998 was sent to every other physician graduated during the years 1977-1986, and the questionnaire in 2003 to every other physician graduated during the years 1982-1991.