Last lecture; Caloric restriction= live longer, fewer cancers, more resistant to disease, toxic molecules, etc. Time magazine: What normal person would want to eat 30% less? (Studies: 40% less.) CRAN: Caloric restriction with adequate nutrition. Collective loss of NCTR researchers= 2400 lbs. Test new drugs in caloric restricted rodents?

Microbiology Lecture 19 Chapter 19 Diagnostic Immunology p.490-504

Early pregnancy test unmarketable? Costs of licensing new drugs, tests often enormous! Orphan Drug Act. Should 3^rd World patients be guinea pigs? Should dumping of outdated drugs in 3^rd World be illegal? Should all new drug data be generated in U.S.?

Marrack's Hypothesis: Precipitation occurs at equivalence. Antigen/antibody excess; no precipitation

Ouchterlony patterns: identity, partial identity, no identity, partial identity, partial nonidentity.

Ouchterlony = "quick and dirty" analysis.

Radial immunodiffusion: Ab in agar, Ag in wells. Large zone = lots of Ag.

[Ag] vs. Log zone diameter = straight line function.

Immunoelectrophoresis fig.19.6. Not in text: Rocket immunoelectrophoresis and CIE (counterimmunoelectrophoresis).

Sensitive = low false negatives, higher false positives. Specific = low false positive, higher false negative rates

best of both worlds: HIV ELISA (sensitive). HIV Western Blot (specific)

Hemagglutination, hemagglutination inhibition, passive hemagglutination, reverse passive hemagglutination, etc. Why so many tests? Each works best for different applications.

Complement fixation.

Monoclonal antibodies: Immortal, uniform sensitivity, uniform specificity. Lots of work to get functioning hybridoma. Immortality = recessive. 1/15,000 penetrance

Various "sandwich" configurations for immunoassays. RIA: disposal of radioisotopes = NIMBY problem. ELISA, EIA = reporter can be Horseradish peroxidase (OPD carcinogenic?)

Indirect immunoassays: Pale antibody in fig. 19.2 actually multiple copies, so, amplify signal.

Rhodamine and fluorescene isothiocyanate for direct, indirect immunofluorescence.

http://benbest.tempdomainname.com/calories/weight.html

Weight Loss for CRAN by Ben Best CALORIES AND WEIGHT LOSSFor a person who is neither gaining nor losing weight, the calories being consumed will equal the sum of calories burned & excreted. It follows that for a person who chooses to reduce calorie intake, a weight loss will occur until a new equilibrium position is reached in which calorie intake again equals calorie consumption/elimination.Individuals with a larger body mass naturally require more energy to maintain that mass. However the calorie-burning effect of a larger body mass is not simply linear, because overweight individuals also have an elevated metabolic rate. For each kilogram of weight lost, metabolic rate has been seen to drop by 20 calories per day [AMERICAN JOURNAL OF CLINICAL NUTRITION 45:1035-1036 (1987)]. Thus, a person beginning a program of Caloric Restriction with Adequate Nutrition (CRAN) should plan for a period of weight loss. CRAN practitioners will either target a new weight or a new level of daily caloric intake, but neither the choice of a target nor the route to the target are obvious. The questions arise: how much weight loss should occur and how rapidly should the weight loss occur? It is impossible to answer these questions with any precision using current scientific knowledge. People vary greatly in initial weight, age, height, health status and bone structure. For a given weight, a person with heavy bone structure will have less muscle&fat than a person of light frame. People of the same weight, height & frame will have a different distribution of lean & fat tissue.

More fundamentally, it has not currently been proven that CRAN extends the lifespan of humans, much less what the optimal CRAN or transition to CRAN is for any specific individual. The best we can expect from current scientific knowledge is information on avoiding the detrimental effects often seen with weight loss.

ADEQUATE NUTRITION: CALORIC REDUCTION VERSUS WEIGHT LOSS

Some CRAN practitioners attempt to trivialize the significance of Adequate Nutrition in Caloric Restriction, but the most knowledgeable researchers in the field rarely speak of restricting calories without emphasizing the importance of sufficient nutrient. Dr. Walford has used the phrase "high/low diet", but never "low diet". There is a good reason for this, not the least of which is the fact that a significant proportion of researchers prior to 1970 failed to properly demonstrate the life-extending properties of Caloric Restriction due to insufficient attention to Adequate Nutrition. Even today, many otherwise-capable scientists still equate CRAN with "starvation". And if scientists do this, what can be expected of the general public?

I am strident about this point not because it is a marketing issue, but because it is an issue of public health. It is known that a majority of those afflicted with anorexia nervosa are young women of high intelligence, yet the damage these women do to themselves is invariably associated with inadequate nutrition. I believe that if interest in CRAN continues to grow in the general public, then there will be increasing numbers of people attempting to practice it. Under these conditions it is socially irresponsible to risk the health & lives of would-be emulators by not emphasizing with every reference that Caloric Restriction MUST be practiced with ADEQUATE NUTRITION.

Moreover, although researchers have demonstrated that Caloric Restriction extends maximum lifespan when Adequate Nutrition is given to prevent deficiency disease, I have doubts that sufficient attention has been given to the nutritional requirements of weight loss. Adequate Nutrition during weight loss is not the same as Adequate Nutrition during steady-state Caloric Restriction. And since adult-onset CRAN invariably results in weight loss, insufficient attention to these additional nutritional requirements -- even in experiments performed with laboratory animals -- may mean that we are still ignorant of the full potential benefits and hazards of adult-onset CRAN.

CALORIES AND WEIGHT LOSS

Weight loss typically means a loss of both fat and lean tissue. The relative proportion of fat and lean loss are most significantly determined by (1) the initial body composition of the subject and (2) whether Caloric Restriction is in an initial or a long-term stage. Concerning (1), lean individuals lose proportionately more lean tissue and obese individuals lose proportionately more fat. A fasting obese person (overweight by more than 50 kilograms -- 110 pounds) will show a 10 gram/kg nitrogen loss compared to a 20 gram/kg nitrogen loss for a fasting normal (nonobese) person. [AMERICAN JOURNAL OF CLINICAL NUTRITION 32:1570-1574 (1979)]. Moreover for a given rate of Caloric Restriction, lean individuals lose weight more rapidly than obese individuals. (This stands to reason, since at 9 calories per gram, a pound of fat represents about 4,000 calories -- in contrast to a pound of protein which would be about 2,000 calories at 4 calories per gram.)

Concerning (2), under conditions of high Caloric Restriction of long duration, after the first week the weight loss in obese individuals will be 10% protein, 40% fat and 50% water, whereas after the first month (and thereafter) something closer to 10% protein, 70% fat and 20% water is seen [ANNUAL REVIEW OF NUTRITION 7:465-484 (1987)]. Not surprisingly, the rate of weight loss during the initial stages of very low calorie diets is much higher than in the later stage. Losses of potassium & sodium are particularly high during the initial state, as is nitrogen loss. Muscle is high in potassium, which is why anorexic patients with severe lean-tissue loss often show potassium depletion [HUMAN BODY COMPOSITION, A.Riche, S.Heymsfield & T.Lohman, Editors (1996), p.275-283 ]. Potassium is the only electrolyte which has been shown to have a clinically significant effect on arrhythmias [CIRCULATION 42:408-419 (1973)].

Loss of lean tissue does not spare the heart. Left ventricular mass of anorexic patients has been seen to be between one-half and two thirds that of age/sex-matched normal subjects [CIRCULATION 72:991-1000 (1985)]. Ventricular arrhythmias are frequently associated with these heart-tissue losses [CIRCULATION 58:425-433 (1978)].