Standardizing analysis of circulating microRNA: clinical and biological relevance

Circulating microRNAs (c-miRNAs) provide a new dimension as clinical biomarkers for disease diagnosis, progression, and response to treatment. However, the discovery of individual miRNAs from biofluids that reliably reflect disease states is in its infancy. The highly variable nature of published studies exemplifies a need to standardize the analysis of miRNA in circulation. Here, we show that differential sample handling of serum leads to inconsistent and incomparable results. We present a standardized method of RNA isolation from serum that eliminates multiple freeze/thaw cycles, provides at least three normalization mechanisms, and can be utilized in studies that compare both archived and prospectively collected samples. It is anticipated that serum processed as described here can be profiled, either globally or on a gene by gene basis, for c-miRNAs and other non-coding RNA in the circulation to reveal novel, clinically relevant epigenetic signatures for a wide range of diseases.

Treatment of postmenopausal women with topical progesterone creams and gels: are they effective?

Topical progesterone creams and gels can be obtained over the counter and/or by prescription from custom-compounding pharmacies and are used by thousands of postmenopausal women for hormonal treatment. However, the effectiveness of these preparations for protecting the endometrium from unopposed estrogen is controversial, due largely to the very low serum progesterone levels that are achieved. Despite these low serum levels, salivary and capillary blood levels are very high and a protective endometrium has been reported in a limited number of studies. Topical alcohol-based, but not water-based, gels appear to yield luteal-phase serum progesterone levels but studies with these preparations are scant. Long-term studies with percutaneous progesterone creams and gels are likely to provide valuable information for treatment of postmenopausal women with this popular route of administration.

Serum Amino Acids (Glutamine, Glutamate, Methionine, and Arginine) Flux after Cutaneous Thermal and Smoke Inhalation injuries in rats

Smoke inhalation injury remains a major co-morbid complication in burn patients. The mortality rate of patients with burns and smoke inhalation injury is reported to be much higher than that of patients with either injury alone. Patients with this combined injury need a more intensive and aggressive nutrition supply to help them survive. The present study, using rats, was designed to test amino acid flux in cases of combined injury (smoke inhalation injury and cutaneous burns). The purpose was to understand the amino acid flux after this combined injury. We tested four different amino acids, i.e. glutamate, glutamine, arginine, and methionine, and hypothesized that different amino acids would be affected differently. Our preliminary results showed that smoke inhalation injury alone did not cause a significant change in amino acid flux during the first five days after injury, but only some increase in arginine three days after injury. In the cutaneous burn and smoke inhalation injury group, all four amino acids decreased immediately and significantly. This result suggests that these four essential amino acids are all conditionally essential amino acids in this combined injury. However, in the simple smoke inhalation injury group, the amino acid supply was not as important, at least in the first five days after injury.

The intrinsic viscosity of mixed protein systems, including studies of plasma and serum

Experimental evidence is presented that the intrinsic viscosity of solutions of mixed proteins obeys the additive equation See PDF for Equation. The datum serves to characterize the system, and combined with other analytical techniques and fractionation procedures, enables one to analyze and characterize subfractions. The plasmas and sera of clinically "normal" individuals give intrinsic viscosity values agreeing with calculated values. The intrinsic viscosity values for pathological plasmas and sera in all cases are greater than normal and reflect the augmented levels of those proteins fibrinogen, α₂-globulins, and γ-globulins occurring in the pathological state. The method is readily adaptable to routine clinical use and furnishes a measure of the departure from normal of protein levels in serum and plasma.

The effects of various horse serum fractions in producing cardiovascular and renal lesions in rabbits

Five groups of 10 rabbits each were injected intravenously 2 times at 15 day intervals with either whole horse serum or one of its cold alcohol-precipitated fractions. Suitable serological and general observations were made at appropriate intervals before and after each injection. All animals were sacrificed on the 22nd day of the experiment. A study of the antemortem and pathological findings led to the following conclusions. 1. Allergie arteritis, valvulitis, and to a lesser degree, focal pericarditis, Aschoff-like nodules, and glomerulitis can be produced by several of the cold alcohol-precipitated fractions of horse serum as well as by whole serum. 2. Most of the acute arteritis was seen in rabbits receiving fraction V (albumin). These rabbits showed the largest amounts of circulating antigen, low antibody titers, low tissue sensitivity, and slight elevation in sedimentation rate and temperature. 3. There was a high incidence of chronic arteritis in the rabbits receiving fraction III which is almost devoid of albumin, suggesting that the alpha and beta globulins in addition to albumin may produce arteritis. 4. A state most nearly resembling that of acute rheumatic fever was produced by either fractions III or IV-3,4 (alpha and beta globulins). Pancarditis (pericarditis, Aschoff-like lesions, and valvulitis) was found relatively frequently. Many of the rabbits developed a high sedimentation rate, elevated temperature, and high tissue sensitivity, but little acute arteritis was found in this group. 5. Gamma globulin (fraction II) produced little reaction either in the antemortem determinations or histopathologically. 6. Glomerulitis of an acute necrotizing type was seen in a few rabbits without particular correlation to the fraction injected. 7. The frequency of involvement of heart valves in rabbit serum disease follows a pattern very similar to that of rheumatic heart disesae. 8. Attempts to correlate antemortem observations and pathological findings either on a group basis or for individual animals failed.

The effect of various experimental states

Further studies are presented on the enzyme in rat serum which hydrolyzes tripropionin, tributyrin, and ethyl butyrate. There is an increase from low levels at birth to normal adult serum lipase activity by about the fourth week of life. The concentration of the enzyme remains quite constant from day to day providing the animals are not bled too frequently, i.e. not more often than once a day. Starvation for a week does not alter serum lipase activity. Additional studies confirm the earlier finding that the lipolytic activity of rat serum ia elevated by alloxan diabetes, and it is shown that insulin, administered over a 24 hr. period, produces a partial return toward normal activity of the enzyme. Decreased serum lipase levels resulted from castration of male and female rats, injection of diethylstilboestrol into normal and gonadectomized animals of both sexes, and late pregnancy. These decreases were all significant, although some of them were transient. It appears that some profound hormonal disturbances may be responsible for these changes.

Effect of the removal of lipids on specific precipitation

Horse antisera to rabbit albumin and globulins and to Type III pneumococci were extracted at low temperatures with alcohol-ether. The precipitin reactions given by these sera deprived of lipids were studied by quantitative analytical methods. With longer periods of standing and slightly higher speeds of centrifugation than those usually required for lipid-containing sera, precipitation may be made complete in immune sera from which the lipids have been removed. The function of lipids in immune reactions is discussed, as well as the effects on antibody globulin of the procedures used in their removal.