The physiological and nutritional importance of dietary fibre.

Fibrous material is an integral part of the daily diet, and it exerts direct physiological effects throughout the gastrointestinal tract, in addition to affecting metabolic activities more indirectly. The interplay of these effects is responsible for the presumed desirable influence of fibre on weight regulation, carbohydrate and lipid metabolism, and on colon function. Numerous mechanisms of action have been identified which are related to the type and the physicochemical nature of the fibre. This review concentrates mainly on the serum cholesterol-lowering effect of dietary fibre, its colonic fermentation, and finally on some possible adverse effects that one should be aware of when consuming high amounts of dietary fibre.     

Calcitonin gene related peptide stimulates adenylate cyclase activity in rat striated muscle

Summary Rat calcitonin gene related peptide (CGRP) and salmon calcitonin (CT) stimulated adenylate cyclase activity in a dose-dependent manner in the rat diaphragm and in the kidney. The ED₅₀ value of rat CGRP was lower and that of salmon CT was higher in the diaphragm than in the kidney. These results suggest that CGRP stimulates adenylate cyclase activity in the striated muscle by reacting with sites distinct from the site in the kidney.     

Mitochondrial DNA deletions in human brain: regional variability and increase with advanced age.

We have examined the role of somatic mitochondrial DNA (mtDNA) mutations in human ageing by quantitating the accumulation of the common 4977 nucleotide pair (np) deletion (mtDNA4977) in the cortex, putamen and cerebellum. A significant increase in the mtDNA4977 deletion was seen in elderly individuals. In the cortex, the deleted to total mtDNA ratio ranged from 0.00023 to 0.012 in 67-77 year old brains and up to 0.034 in subjects over 80. In the putamen, the deletion level ranged from 0.0016 to 0.010 in 67 to 77 years old up to 0.12 in individuals over the age of 80. The cerebellum remained relatively devoid of mtDNA deletions. Similar changes were observed with a different 7436 np deletion. These changes suggest that somatic mtDNA deletions might contribute to the neurological impairment often associated with ageing.     

New human and simian HIV-related retroviruses possess functional transactivator (tat) gene

New human retroviruses antigenically related to HIV and even more closely to STLV-III have been recently isolated from individuals from some West African countries. One of these viruses, HTLV-IVP, was reportedly isolated from lymphocytes of a healthy female prostitute. Another isolate, LAV-2FG, was obtained from an AIDS patient and third, SBL-6669, from an individual with lymphadenopathy. Current epidemiological studies indicate that some of these virus isolates cause immune deficiency whereas others may not or may be less efficient at inducing immune deficiency. Similarly, STLV-III apparently does not cause immune deficiency in its natural host, African green monkey. A novel feature of HIV is the possession of a gene termed tat, which is implicated in its pathobiology. We report here that, like HIV, HTLV-IVP, LAV-2FG (HIV-2) and SBL-6669, as well as STLV-IIIAGM possess the putative tat gene, irrespective of their pathogenic potential in vivo. Interestingly, HTLV-IVP/LAV-2FG long terminal repeat (LTR) is equally well transactivated by the HTLV-IVP/LAV-2FG and HTLV-IIIB tat function, HTLV-IIIB LTR responds better to its own tat function.     

Modelling peak electricity demand

This paper estimates a forecasting equation for the hourly peak electricity demand one day in the future. The models incorporate deterministic influences such as holidays, stochastic influences such as average loads by building bivariate models, and exogenous influences such as the weather which is given a careful non-linear formulation. Out-of-sample comparisons are made using an additional year of data.     

Identical point mutations of PMP-22 in Trembler-J mouse and Charcot-Marie-Tooth disease type 1A.

We have investigated the peripheral myelin protein gene, PMP-22, in a family with Charcot-Marie-Tooth disease type 1A (CMT1A). The DNA duplication commonly found in CMT1A was absent in this family, but strong linkage existed between the disease and the CMT1A marker VAW409R3 on chromosome 17p11.2. We found a point mutation in PMP-22 which was completely linked with the disease. The mutation, a proline for leucine substitution in the first putative transmembrane domain, is identical to that recently found in the Trembler-J mouse. The presence of this PMP-22 defect in this CMT1A family and the location of PMP-22 within the DNA duplication associated with CMT1A suggest that both structural alteration and overexpression of PMP-22 may lead to the disease.