galactosemia

source :
http://learn.genetics.utah.edu/content/disorders/whataregd/galactosemia/

 http://en.wikipedia.org/wiki/Galactosemia

   
http://www.newbornscreening.info/Parents/otherdisorders/Galactosemia.html

metabolizm of glactose

source : http://themedicalbiochemistrypage.org/non-glucose-sugar-metabolism.php

Pentose phosphate pathway

The pentose phosphate pathway oxidizes glucose to make NADPH and other carbohydrates for biosynthesis (see Figure 1  ). The major route for reduction of NADP to NADPH is the reaction of glucose‐6‐phosphate through two successive reactions. In the first, carbon 1 of glucose is oxidized from an aldol to an esterform (actually, an internal ester, called a lactone) by glucose‐6‐phosphate dehydrogenase. In the second reaction, the same carbon is further oxidized to CO ₂and released, leaving behind a 5‐carbon sugar, in a reaction catalyzed by 6‐phosphogluconolactone‐dehydrogenase. Both reactions reduce NADP to NADPH. The 5‐carbon residue is ribulose‐5‐phosphate.


source : http://www.cliffsnotes.com/sciences/biology/biochemistry-i/carbohydrate-metabolism-ii/the-pentose-phosphate-pathway
http://en.wikipedia.org/wiki/Pentose_phosphate_pathway

Scientists discover genetic causes of pancreatitis

 

HYDERABAD: A team comprising doctors from Asian Institute of Gastroenterolgy (AIG) and scientists from Centre for Cellular and Molecular Biology (CCMB) along with international researchers have discovered hitherto unknown genetic causes for Chronic Pancreatitis in Indian populations. These findings will be published in the prestigious international journal Nature Genetics.

Addressing the media here on Sunday, CCMB director C H Mohan Rao said the study showed genetic mutations found in western populations need not necessarily be found in Indian populations. Pancreatitis is an inflammatory disorder of the pancreas, the organs which produce essential digestive enzymes in addition to producing insulin for sugar metabolism in the body.

The decade long research by Dr G R Chandak of CCMB, Dr D Nageshwar Reddy and Dr G V Rao of AIG representing India, involved genetic analysis of 300 patients, from Europe and Asia, afflicted with Tropical Calcific Pancreatitis which is one type of pancreatitis found largely in populations in south India. The research team's recent discovery was identification of a mutation in an essential enzyme producing Carboxypeptidase A1 gene (CPA1) in the Indian patients which caused functional loss of the enzyme.

Dr Chandak said, "The study has found a novel mutation in CPA 1 gene that was not found in non-Indian patients. This condition has an early onset in the patients that is many of them were young people.

The study could pave the way for improved diagnosis in India populations later."

The team's previous discoveries have included identification of mutations in two other genes corroborating the idea that pancreatitis has strong genetic factors and not just environmental or nutritional factors as was previously thought.

How skin is maintained throughout life

Washington: Researchers have tried to explain how the skin, which is our largest organ and forms a shield against the environment, is maintained throughout its life.

The skin consists of many different cell types, including hair cells, fat- and sweat glands. It protects us against microbial and chemical attacks and forms a waterproof barrier that prevents fluid loss.

Associate professor Kim Jensen` group from BRIC, University of Copenhagen, have through mapping of stem cell`s behaviour in the skin, found out that the skin uses a unique method to renew itself.

She said that until now, the belief was that the skin`s stem cells were organized in a strict hierarchy with a primitive stem cell type at the top of the hierarchy, and that this cell gave rise to all other cell types of the skin.

Jensen said that however, their results showed that there are differentiated levels of stem cells and that it is their close micro-environment that determines whether they make hair follicles, fat- or sweat glands.

She asserted that their data completes what is already known about the skin and its maintenance.

Jensen explained that researchers have until now tried to fit their results into the old model for skin maintenance.

However, the results give much more meaning when we relate them to the new model that our research proposes, says Kim Jensen.

For their endeavour, Kim Jensen`s research group has used a unique method based on new technology, to understand how the skin is maintained.

Jensen said that they have marked the early skin stem cell with shining proteins in order to map stem cell behaviour in the outer layer of the skin.

She asserted that the stain is inherited by the daughter cells, so that we can trace their origin and make a family tree.

Jensen said that the fine details of the family tree can be used to infer the stem cell`s role in normal maintenance of the skin, as well as in wound healing.

An important function of stem cells is to repair damaged tissue. Here, the results from the Jensen groups show that the different stem cell populations collaborate across their normal functions, to repair the skin as fast as possible.

However, this can also cause harm, as these changes can "wake up" genes in the stem cells and give rise to cancer. The new results consequently also contribute with new knowledge on the origin of skin cancer.

The results have just been published in the recognized journal Cell Stem Cell.

Roller mills

 

Roller mills are similar to roller crushers, but they have smooth or finely fluted rolls, and rotate at differential speeds. They are used very widely to grind flour. Because of their simple geometry, the maximum size of the particle that can pass between the rolls can be regulated. If the friction coefficient between the rolls and the feed material is known, the largest particle that will be nipped between the rolls can be calculated, knowing the geometry of the particles.

Miscellaneous milling equipment

The range of milling equipment is very wide. It includes ball mills, in which the material to be ground is enclosed in a horizontal cylinder or a cone and tumbled with a large number of steel balls, natural pebbles or artificial stones, which crush and break the material. Ball mills have limited applications in the food industry, but they are used for grinding food colouring materials.
The edge runner mill, which is basically a heavy broad wheel running round a circular trough, is used for grinding chocolate and confectionery.
Many types of milling equipment have come to be traditional in various industries and it is often claimed that they provide characteristic actions that are peculiarly suited to, and necessary for, the product.

GRINDING AND CUTTING

Grinding and cutting reduce the size of solid materials by mechanical action, dividing them into smaller particles. Perhaps the most extensive application of grinding in the food industry is in the milling of grains to make flour, but it is used in many other processes, such as in the grinding of corn for manufacture of corn starch, the grinding of sugar and the milling of dried foods, such as vegetables.

Cutting is used to break down large pieces of food into smaller pieces suitable for further processing, such as in the preparation of meat for retail sales and in the preparation of processed meats and processed vegetables.

In the grinding process, materials are reduced in size by fracturing them. The mechanism of fracture is not fully understood, but in the process, the material is stressed by the action of mechanical moving parts in the grinding machine and initially the stress is absorbed internally by the material as strain energy. When the local strain energy exceeds a critical level, which is a function of the material, fracture occurs along lines of weakness and the stored energy is released. Some of the energy is taken up in the creation of new surface, but the greater part of it is dissipated as heat. Time also plays a part in the fracturing process and it appears that material will fracture at lower stress concentrations if these can be maintained for longer periods. Grinding is, therefore, achieved by mechanical stress followed by rupture and the energy required depends upon the hardness of the material and also upon the tendency of the material to crack - its friability.

The force applied may be compression, impact, or shear, and both the magnitude of the force and the time of application affect the extent of grinding achieved. For efficient grinding, the energy applied to the material should exceed, by as small a margin as possible, the minimum energy needed to rupture the material . Excess energy is lost as heat and this loss should be kept as low as practicable.
The important factors to be studied in the grinding process are the amount of energy used and the amount of new surface formed by grinding.