The Bedouin Infant Feeding Study: study design and factors influencing the duration of breast feeding

Summary. A longitudinal study of infant feeding practices, growth and morbidity among Bedouin Arab infants residing in the Negev, Israel, was conducted during a 3-year period (1981–1983). Follow-up samples were restricted to healthy newborns. The majority of newborns are breast fed at birth but, by 2 months, 50% are also introduced to a milk supplement. Based on the bivariate analysis using the logrank test to examine the factors associated with exclusive versus partial breast feeding during the first 6 months, those born during the wet cool months are exclusively breast fed longer than those born during the dry season. More traditional women, living in tents rather than houses or huts, exclusively breast feed for at least 6 months. In a multiple logistic regression model, parity, house type and birth season are independently associated with the odds of exclusively breast feeding for the first 6 months of life. Factors influencing the duration of any breast feeding for the first 18 months include: house type, place of residence, birthweight, and whether the infant was stunted at 6 months.     

The Bedouin Infant Feeding Study: study design and factors influencing the duration of breast feeding.

A longitudinal study of infant feeding practices, growth and morbidity among Bedouin Arab infants residing in the Negev, Israel, was conducted during a 3-year period (1981-1983). Follow-up samples were restricted to healthy newborns. The majority of newborns are breast fed at birth but, by 2 months, 50% are also introduced to a milk supplement. Based on the bivariate analysis using the logrank test to examine the factors associated with exclusive versus partial breast feeding during the first 6 months, those born during the wet cool months are exclusively breast fed longer than those born during the dry season. More traditional women, living in tents rather than houses or huts, exclusively breast feed for at least 6 months. In a multiple logistic regression model, parity, house type and birth season are independently associated with the odds of exclusively breast feeding for the first 6 months of life. Factors influencing the duration of any breast feeding for the first 18 months include: house type, place of residence, birthweight, and whether the infant was stunted at 6 months.     

Dietary fibre fermentation in the rat intestinal tract: effect of adaptation period, protein and fibre levels, and particle size

1. The fermentative breakdown of one resistant type of dietary fibre (wheat bran) and one easily-fermented fibre (low-methoxyl pectin) was studied with respect to the length of the adaptation period and fibre level in the diet. The breakdown of the resistant fibre was also studied regarding the protein level in the diet and particle size of the fibre. 2. Prolongation of the adaptation period from 4 to 18 d decreased the faecal dry weight considerably. The excretion of dietary fibre however, was similar, whereas a decrease in faecal nitrogen excretion could be seen. 3. A level of dietary protein of less than 50 g/kg impaired the fermentation of wheat-bran fibre, whereas a level higher than 100 g protein/kg did not further increase the degree of fermentation of the fibre. 4. The particle size did not change the fermentability of the fibre, equal amounts of the main components of coarse and milled bran being excreted in faeces. 5. Two different levels of wheat-bran fibre (48 and 96 g/kg) in the diet did not influence the fibre breakdown. Similar results were obtained with two levels of fibre from low-methoxyl pectin (42 and 84 g/kg), but a tendency towards a decreased percentage of faecal excretion of uronic acids was seen at the lower level of low-methoxyl pectin.     

High-level dietary fibre up-regulates colonic fermentation and relative abundance of saccharolytic bacteria within the human faecal microbiota in vitro

Background

Health authorities around the world advise citizens to increase their intake of foods rich in dietary fibre because of its inverse association with chronic disease. However, a few studies have measured the impact of increasing mixed dietary fibres directly on the composition of the human gut microbiota.

Aims of the study

We studied the impact of high-level mixed dietary fibre intake on the human faecal microbiota using an in vitro three-stage colonic model.

Methods

The colonic model was maintained on three levels of fibre, a basal level of dietary fibre, typical of a Western-style diet, a threefold increased level and back to normal level. Bacterial profiles and short chain fatty acids concentrations were measured.

Results

High-level dietary fibre treatment significantly stimulated the growth of Bifidobacterium, Lactobacillus-Enterococcus group, and Ruminococcus group (p?Faecalibacterium prausnitzii in vessel 1 mimicking the proximal colon (p?p?Conclusions This study shows that high-level mixed dietary fibre intake can up-regulate both colonic fermentation and the relative abundance of saccharolytic bacteria within the human colonic microbiota. Considering the important role of short chain fatty acids in regulating human energy metabolism, this study has implications for the health-promoting potential of foods rich in dietary fibres.     

Assessment of sutures for use in colonic surgery: an experimental study

Following injury, normal colon takes approximately 30 days to regain full breaking strength. This healing period can be lengthened by local infection. Colonic anastomoses are likely to be contaminated by intraluminal organisms, and suture material in such a situation is known to potentiate the development of sepsis. Experiments were designed to evaluate six suture materials used in colonic surgery to determine which retained adequate tensile strength and which excited least inflammatory response. The results indicate that absorbable sutures, with the exception of polydioxanone, lose strength too rapidly for use alone. Braided materials, notably silk, produce a prolonged tissue response and harbour bacteria. Monofilament materials are unreactive and appear least likely to delay healing. Polydioxanone, which is monofilament and absorbable, is recommended for use in the colon.     

The effect of weaning diet on the subsequent colonic metabolism of dietary fibre in the adult rat.

The effect of the weaning diet on the subsequent colonic metabolism of bran and pectin in the adult rat has been investigated. Feeding a fibre-reduced diet on its own or supplemented with bran (WB) and pectin (P) from weaning (fibre-reduced (weaning)) was compared with introducing the same diet to age-matched rats reared on a standard laboratory diet from weaning (fibre-reduced (6 weeks)). The effects of the diets on colonic metabolism were measured by wet and dry caecal contents and stool weights, caecal sac weight, and caecal and faecal short-chain fatty acids (SCFA). Final body-weights were greater for fibre-reduced (6 weeks) and fibre-reduced (6 weeks) + P groups, but not fibre-reduced (6 weeks) + WB, than those of the fibre-reduced (weaning) rats. Rats fed on fibre-reduced (6 weeks) diet had a higher total caecal SCFA content than fibre-reduced (weaning) control rats. Fibre-reduced (weaning) + P-fed rats had a threefold higher caecal concentration of both propionate and butyrate than the matched fibre-reduced (6 weeks) + P group. Fibre-reduced (weaning) + WB animals had a significantly higher butyrate caecal concentration compared with their matched fibre-reduced (6 weeks) + WB group. Fibre-reduced (weaning) + P-fed rats had a lower faecal output than the fibre-reduced (6 weeks) + P rats. There was no difference in faecal output in rats fed on either fibre-reduced (6 weeks) + WB or fibre-reduced (weaning) + WB. The faecal concentration of SCFA was in general higher in the rats fed on fibre-reduced (weaning) alone, + P, or + WB than in those fed on fibre-reduced (6 weeks) alone, + P or + WB. Faecal output of total and individual SCFA was increased on the fibre-reduced (weaned) + WB diet compared with fibre-reduced (6 weeks) + WB-fed animals. The diet at weaning may be important in determining the pathways of caecal bacterial metabolism in the adult rat. In studying the effect of a dietary fibre on caecal metabolism and faecal output, when the diet is changed appears to be important.     

Histochemical study of asbestos fibre coating in experimental carrageenin granulomas

Governa, M., and Rosanda Vadalà, C. (1973).British Journal of Industrial Medicine,30, 248-252. Histochemical study of asbestos fibre coating in experimental carrageenin granulomas. To study the composition of asbestos body coating, asbestos particles present in experimental carrageenin granulomas were tested histochemically for mucopolysaccharides, ferric and ferrous iron, haemoglobin, and haematoidin. The stains were applied on microscopical sections both untreated and treated with iron-extracting solutions and/or enzymes. The results indicate that asbestos is rapidly coated with haematoidin, ferric iron, and hyaluronic acid.     

Do mothers overestimate breast feeding duration? An example of recall bias from a study in southern Brazil

The problem of recall bias when reporting breast feeding duration is investigated. Data are presented from the follow-up of over 1,000 children from a birth cohort (1982) in southern Brazil, when they were on average 11, 23, and 47 months of age. Compared with the response given at 11 months of age, 24% of mothers misclassified the duration (grouped into 3-month categories) at age 23 months and 30% at age 47 months. Women who were richer and/or better educated were significantly more likely to report longer durations, while those poorer and less educated did not tend to misclassify more in one direction than in the other.     

Host behaviour and mosquito feeding success: an experimental study

The susceptibility of laboratory rabbits to attack by mosquitoes (Aedes aegypti) is found to be closely linked to their grooming activity. Prevention of grooming significantly increases both the percentage of mosquitoes feeding and the size of blood meals. Grooming responses intensify with parasite density, and lead to a slight decline in parasite feeding success and blood meal size. Grooming efficiency varied between individual rabbits and also a consequence of experience, with rabbits improving their ability to deter mosquitoes in response to the intensity and/or duration of previous exposures.     

Hospital practices and duration of breast feeding: meta-analysis

Clinical trials studying the influence of hospital practices on breast-feeding duration were combined in a meta-analysis. Nine studies were selected. The global quality score was poor, and varied between 11.6 and 71.5 (Chalmers' scale). The results of each study were pooled using Peto's method and showed the following findings. Supplementation demonstrated a negative clinical effect on breast-feeding duration which was not significant (OR: 0.77, 95% CI[0.59, 1.02] p greater than 0.05). Nursing support demonstrated a positive clinical effect on breast-feeding duration which was not statistically significant if there was no telephone follow-up (OR : 2.29, 95% CI [0.87, 6.02] p greater than 0.05), but was significant if there was telephone follow-up (OR : 2.01, 95% CI [1.37, 2.94] p less than 0.05). Early contact revealed a positive clinical effect which was significant (OR : 2.96, 95% CI [1.6, 5.22] p less than 0.05). In conclusion, early contact and nursing support with telephone follow-up appear as enhancing factors of breast-feeding duration.     

培本方调节哮喘大鼠HPA轴紊乱的实验研究

[目的]研究培本方对哮喘大鼠下丘脑-垂体-肾上腺(HPA)轴紊乱的调节作用。[方法]采用卵蛋白(OVA)致敏、激发复制大鼠慢性哮喘模型,以阿斯美胶囊为对照药,通过检测血清皮质酮(CORT)、血浆促肾上腺皮质激素(ACTH)及下丘脑促肾上腺皮质激素释放激素(CRH)含量的变化,探讨培本方对大鼠哮喘模型的影响。[结果]模型组较正常组CORT及CRH含量均显著降低,ACTH含量无明显改变;经培本方治疗后,CORT及CRH含量均可明显升高,且培本方高剂量组可使ACTH水平有所增高。[结论]培本方抗哮喘作用的机制之一为纠正哮喘HPA轴紊乱。     

Development of a food composition database to study complementary feeding: An Italian experience

Food Composition Databases (FCDBs) are important tools for epidemiological research, public health nutrition and education, clinical practice and nutrition declaration on food labels. The aim of this paper is to describe the methodology used to compile a FCDB for the analysis on the dietary intake of an Italian cohort of infants, and to assess its strengths and weaknesses. Dietary data were collected using a 3-DD records compiled at 6, 9 and 12 months of age of the infants. We developed a FCDB that contains data from the Italian and the USDA food composition databases and other sources. Our FCDB includes 563 food derived from the analysis of 623 3-DD records. Non-commercial products are more consumed than commercial products (25.5% vs. 9.1% at 6 months, 58.4% vs. 18.1% at 9 months and 77.8% vs. 11.3% at 12 months) but the latter are the main source of missing data (>70% in each database, with the exception of the energy components), which is one of the major weaknesses of this tool. An integrated system of data collection (NUTRIRETE.lab) that brings together food composition data from public and private laboratories will allow us to build a more complete and representative food composition database.     

An experimental design for the simulation of combined-acting pollutants

A short review is given of concepts which are used to evaluate effects from combined-acting agents. To explore those effects exactly a high multiplicity of experiments must be performed, as an algebraic derivation from the effects of the single-acting agents is not usually possible. For practical purposes (as, for instance, to establish threshold limit values with respect to occupational health standards) a more pragmatic concept is proposed. Accordingly, an experimental setup has been developed which enables us to expose four groups of rodents simultaneously to two different single-acting chemical and/or physical stress parameters, both separately and in combination, and to control conditions.     

Mechanism of the damage to myelinated axons in experimental Creutzfeldt-Jakob disease in mice: An ultrastructural study

We report the ultrastructural pathology of myelinated axons in mice infected experimentally with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD). Initially the myelin sheath was separated into several concentric bands, and cellular processes penetrated between layers of myelin and lifted away the outermost lamella. Then a complicated labyrinth of the concentric cellular processes, clearly belonging to either astrocytes or macrophages, invested myelinated axons. In terminal stages axons completely denuded of myelin were seen in the center of concentric networks of cellular processes. Myelin remnants were seen within astrocytes and macrophages. We conclude that the mechanism(s) of damage to myelinated axons in CID may be similar to that operating in immunologically mediated demyelinating disorders.Corresponding author.     

An experimental study on the duration of a single spell of work on VDT (visual display terminal) performance

The relation between work load and the duration of a single spell of work on VDT performance studied in an experimental word processing task. Nine healthy male college students performed 2-hour visual tasks under the following three sets of work conditions. In the first set, subjects performed VDT work for two hours without intermission. In the second set, subjects had a 10-minute intermission after a 1-hour task. In the third set, there was a 5-minute intermission after a 30-minute task. Critical flicker fusion, near point distance, subjective fatigue symptoms, heart rate, respiratory rate, blinking counts, electromyogram in upper limb and performance score were measured. Results are as follows. Decrease in critical flicker fusion, increase in near point distance and subjective fatigue symptoms appeared in all three sets of experimental conditions after two hour tasks. Increased slow wave components on electromyogram and increased errors in performance appeared after 60-minute or more tasks without intermission. Effects on the critical flicker fusion, near point distance, subjective fatigue symptoms, electromyogram, blinking counts and errors in performance were least in the third set. The results of this study suggest that in order to reduce operators' fatigue on VDT work of the conversation type, countermeasures such as shortening the duration of a single spell of work to less than 60 minutes and taking frequent short intermission are necessary.     

Pulmonary retention of lead: An experimental study in man

This human investigation of lead absorption from the lungs utilized two forms of lead, lead chloride and lead hydroxide; the former was used in picogram amounts and the latter at microgram levels. These two species of lead were selected in an attempt to simulate the range of physicochemical properties found in atmospheric lead (urban air). Aerosols labeled with lead-203 were made of comparable aerodynamic size (MMAD 0.25 μm ± 0.1) by using sodium chloride as the deposition-determining aerosol. After brief, mouthpiece exposures, 17 subjects were followed by serial counting with a thoracic array of 12 2-in. scintillation detectors and two 2-in. leg counters, all coupled to single channel analyzers. Serial blood samples were also taken. The two exposure groups showed similar total deposition values (23 vs 26%) and the same biological retention halftimes, viz., 22.6 hr. When the retention data were “corrected” for blood-borne ²⁰³Pb, the biological halftimes for lung lead retention averaged 13.1 and 14.2 hr, respectively, and were not significantly different. Blood build-up data were also indistinguishable in the two groups. The authors discuss these findings in relation to other inhalation studies and conclude the collective evidence supports the view that atmospheric lead is rapidly and completely absorbed from the human lungs.