Endogenous Cryogens Existing in the Blood of a Hypothermic Patient

Abstract

tions except hypothermia-associated symptoms such as bradycardia, hypotension and slow body movement. In the laboratory data, however, there were some abnormal findings, e.g., slight increases in plasma levels of the BUN, electrolytes (Na and Cl), and energy substrates (total cholesterol, triglyceride, and blood sugar). The hematological changes were judged to be induced by hemoconcentration or hypometabolism associated with hypothermia. The plasma levels of TSH and some liver enzymes (GOT, GPT, and LDH) were slightly increased, indicating the possibility of hypothyroidism. However, plasma concentrations of free thyroxin and free triiodothyronine were within normal ranges; furthermore, l-thyroxin replacement therapy did not improve hypothermia. There were no other abnormal findings, e.g., in pituitary function tests or in magnetic resonance imaging studies of the head, especially in the hypothalamo-pituitary region. So even though we performed various physical, psy- Abstract:We treated a young female patient who suffered from severe hypothermia. The etiology of the hypothermia was not identified, though various medical examinations were performed. Intraperitoneal (i.p.) injections of the patient's serum produced a significant and profound hypothermia in rats that was not associated with circulatory shock. The patient's serum was separated into 4 fractions by the use of various types of centrifugal filtration units according to molecular weights (MW), i.e., below 10 kDa, 10-30 kDa, 30-100 kDa, and beyond 100 kDa. The first two fractions never induced hypothermia in rats, but the i.p. injections of the fraction with MW from 30 to 100 kDa consistently produced hypothermia. The fraction with MW beyond 100 kDa caused marked hypothermia in one out of 3 rats tested. The results suggest that the patient was excessively producing endogenous cryogenic substances of which MW may be greater than 30 kDa.

Possible Human Endogenous Cryogens

“…Intraperitoneal injections of the patient's serum in a volume of about 1.0 ml produced a consistent and profound hypothermia in rats Fig. (2) [33]. Interestingly, sera from two of 14 healthy controls caused hypothermia in rats.…”

“…Thus, substances causing the second type of anapyrexia may be more useful for maintaining a low T cor . Since human endogenous cryogens we have reported here [27,33,34] appear to have less adverse effects, identification of the cryogens could be beneficial.…”

“…To identify molecular weights (MW) of possible cryogens, the patient's serum was separated into 4 fractions by the use of various types of centrifugal filtration tubes and membranes according to MW, i.e., below 10 kDa, 10 -30 kDa, 30 -100 kDa, and beyond 100 kDa [33]. The first two fractions never induced hypothermia in rats, but the i.p.…”

Proyecto lázaro (2016): de la criopreservación celular a humana. Mito y realidad para la formación docente en el área de ciencias de la salud

“…La anapirexia se define como la caída regulada de la temperatura central, siendo esta beneficiosa para los animales y los seres humanos cuando el suministro de oxígeno en diferentes condiciones (como hipoxia e isquemia) es limitado, como una estrategia para reducir el consumo de oxígeno. Además de la hipoxia, la anapirexia puede ser inducida por diversas sustancias exógenas y endógenas capaces de producir hipotermia, denominadas criógenos 5,6 . El conocimiento para la sobreexpresión de estas proteínas criógenicas endógena se podrían considerar de gran utilidad en diferentes actividades humanas como la estasis espacial y en terapias de hipotermia cerebral.…”