Mathematical Simulation and Numerical Computation of the Temperature Profiles in the Peripherals of Human Brain during the Tepid Sponge Treatment to Fever.

BACKGROUND: Fever is one of the frequently occurring diseases in human beings, and the body is said to have befallen in fever if the arterial or internal body temperature rises to 38°C. The patient who suffers from fever is either given paracetamol or tepid sponging or both. OBJECTIVE: This paper is aimed at studying the effects of the tepid sponge in normalizing the high temperature of the human body during fever. Among the various available methods for tepid sponging, the impact of holding a cool wet cloth on the forehead for reducing the fever is analyzed and pictured graphically. METHOD: For analyzing the effects of tepid sponge on the temperature distribution of the domain consisting of scalp, skull, and cerebrospinal fluid (CSF), a cool wet cloth is brought in contact with the skin allowing the heat to transfer from the brain to the wet cloth through these layers. The heat transfer in living biological tissues is different from ordinary heat transfer in other nonliving materials. Therefore, a model based on the bioheat equation has been constructed. The model has been solved by numerical methods for both steady- and unsteady-state cases. The domain, which consists of the scalp, skull, and CSF layers of the human head, has been discretized into four equal parts along the axes of the three-dimensional coordinate system. The forward difference and forward time centered space approximations were employed for numerical temperature distribution results at the nodal points. RESULTS: The effects of tepid sponge in reducing the body temperature with fever at 38°C, 39.5°C, and 41°C have been numerically calculated, and the results were pictured graphically. For transient cases, the corresponding calculations have been carried out at times t = 2 minutes, 4 minutes, and 6 minutes. CONCLUSION: Among all the available remedies to fever, tepid sponging has shown a significant effect in controlling fever.

[Efffect of baicalin on antipyresis and influence on cytokine].

OBJECTIVE: To study the antipyretic effect of baicalin in inhibiting yeast-induced fever in rats and the influence on inflammatory cytokine, then explore the possible mechanism of baicalin in inhibiting yeast-induced fever in rats. METHODS: Rat modles of pyrexia were established by subcutaneous injection of yeast (2 g x kg(-1)); the rats of were divided into the normal control, model, baicalin high, medium and low-dose group and the effect of baicalin on the changes of the rats' temperature were observed. Dual antibody ELISA method was used to test the changes of IL-6, IL-1beta and TNF-alpha contents in in serum , hypothalamus and cerebral spinal fluid (CSF). Then analyze the correlation between the inhibition ratio of temperature heighten on three different dose of baicalin and the inhibition ratio of the contents heighten on IL-6, IL-1beta and TNF-alpha. RESULT: The high dose of baicalin significantly inhibited the yeast-induced fever of rats, and decresesed IL-6, IL-1beta and TNF-alpha contents in serum, hypothalamus and CSF. The inhibition ratio of temperature heighten of baicalin had direct correlation with the inhibition ratio of the heighten on IL-1beta content in serum, hypothalamus and CSF (r = 0.873, P < 0.05), also dose TNF-alpha (r = 0.862, P < 0.01). CONCLUSION: Baicalin may have obvious antipyretic effect by decreasing the increasing contents of IL-1beta and TNF-alpha in rats.

Characterization and pharmacological evaluation of febrile response on zymosan-induced arthritis in rats.

The present study investigated the febrile response in zymosan-induced arthritis, as well as the increase in PGE(2) concentration in the cerebrospinal fluid (CSF), along with the effects of antipyretic drugs on these responses in rats. Zymosan intra-articularly injected at the dose of 0.5 mg did not affect the body core temperature (Tc) compared with saline (control), whereas at doses of 1 and 2 mg, zymosan promoted a flattened increase in Tc and declined thereafter. The dose of 4 mg of zymosan was selected for further experiments because it elicited a marked and long-lasting Tc elevation starting at 3 1/2 h, peaking at 5 1/2 h, and remaining until 10 h. This temperature increase was preceded by a decrease in the tail skin temperature, as well as hyperalgesia and edema in the knee joint. No febrile response was observed in the following days. In addition, zymosan-induced fever was not modified by the sciatic nerve excision. Zymosan increased PGE(2) concentration in the CSF but not in the plasma. Oral pretreatment with ibuprofen (5-20 mg/kg), celecoxib (1-10 mg/kg), dipyrone (60-240 mg/kg), and paracetamol (100-200 mg/kg) or subcutaneous injection of dexamethasone (0.25-1.0 mg/kg) dose-dependently reduced or prevented the fever during the zymosan-induced arthritis. Celecoxib (5 mg/kg), paracetamol (150 mg/kg), and dipyrone (120 mg/kg) decreased CSF PGE(2) concentration and fever during zymosan-induced arthritis, suggesting the involvement of PGE(2) in this response.

Inhibition of interleukin-1 beta-induced pyresis in the rabbit by peptide 204-212 of lipocortin 5.

The intracerebroventricular administration of interleukin-1 beta (12.5 ng/kg) in rabbits caused a prompt rise of prostaglandin E2 concentration (+ 632.6 +/- 243.9%) in the cerebrospinal fluid followed by hyperthermia (+ 1.61 +/- 0.14 delta degrees C). The intracerebroventricular administration of an anti-inflammatory nonapeptide (amino acids 204-212, SHLRKVFDK) derived from lipocortin 5, thereafter referred to as lipocortin 5-(204-212)-peptide, inhibited in a significant manner both the increase in cerebrospinal fluid [prostaglandin E2] and the febrile response induced by the cytokine. This inhibitory effect is probably due to interference by the peptide with phospholipase A2 activity. A control peptide (FKRVHDLKS) formed by the same amino acids in a randomly shuffled sequence had no effect. These results show that, in addition to the anti-inflammatory effect previously reported, the peptide 204-212 of lipocortin 5 possesses, like glucocorticoids, anti-pyretic activity. The research on lipocortin-derived peptides may lead to the development of novel anti-inflammatory and anti-pyretic compounds.

[Analysis of changes in serotonin, histamine, and prostaglandin E2 levels in cerebrospinal fluid and body tissues during hyperthermia of various origins]. / Analiz izmenenii soderzhaniia serotonina, gistamina i prostaglandina E2 v spinomozgovoi zhidkosti i tkaniakh organizma pri gipertermiiakh razlichnogo proiskhozhdeniia.

Physical hyperthermia caused distinct increase in content of serotonin in liquor and its decrease in hypothalamus of rabbits and rats, while histamine and PGE2 were unaltered in liquor of these animals. Considerable increase of PGE2 in liquor simultaneously with unaltered content of serotonin and histamine were detected in rabbits with pyrogenal-caused fever. A decrease in PGE2 content and elevation of serotonin were found in animals liquor after normalization of body temperature within 7 hrs of the pyrogenal treatment. The biogenic amines studied appear to serve as constituents of the natural antipyretic body system in animals, whereas PGE2 belongs to factors responsible for elevation of body temperature.

[Effect of Rheum tanguticum Maxim ex Balf on cAMP in the central nervous system].

Rabbit model of fever was produced by means of subcutaneous inoculation of pneumocci. Third ventricular intubation and irrigation were carried out in rabbits. Irrigation fluid was collected during the stage of normal temperature, at the peak of fever and when the temperature was lowered by rhubarb. cAMP was detected with RlA in each of the three portions of the irrigated CSF. The result showed that cAMP level was raised during fever and decreased after rhubarb administration. Irrigation of CSF without medication had no significant influence on cAMP level.

Prostaglandin E2 and fever: a continuing debate.

Prostaglandin (PG) E2 is a potent hyperthermic agent and has been assigned an intermediary function in the response of thermoregulatory neurons to pyrogens. Though attractive, this idea has been challenged on several grounds. The present study confirms that brain PGE2 synthesis increases during fever, the time course of the elevation according with a causative role of the compound. Our experimental data also argue against the involvement of a second cyclooxygenase product, specifically thromboxane (TX) A2, in the action of pyrogens. The sequence of events leading to PGE2 production and fever differs depending on the pyrogen, bacterial vs. leucocytic, and its route of administration. Blood-borne interleukin-1 (IL-1) acts on a discrete site in the central nervous system (CNS) which is tentatively identified with the organum vasculosum laminae terminalis (OVLT). The same site may also be the target for blood-borne endotoxin. In addition, endotoxin may promote PGE2 synthesis in the cerebral microvasculature. Both pyrogens, on the other hand, act diffusely throughout the CNS when given intrathecally. We conclude that PGE2 is well suited for an intermediary role in the genesis of fever and ascribe the reported inconsistencies to methodological factors.

Evidence for the involvement of adenosine 3',5'-cyclic monophosphate in fever genesis.

In rabbit cerebrospinal fluid (CSF) during fever induced by endotoxins, myxoviruses, or endogenous pyrogen, concentrations of adenosine 3',5'-cyclic monophosphate (cyclic AMP) and prostaglandin E (PGE) are about 2-fold higher in comparison to normal values. In endotoxin treated animals paracetamol reduced the fever reaction and both PGE and cyclic AMP levels. Administration of theophyllin together with endotoxin enhanced the fever reaction and cyclic AMP levels in CSF, but had no influence on stimulation of PGE synthesis. Following injection of PGE2 into the lateral cerebral ventricles increased cyclic AMP concentrations were found in CSF. The results suggest, that the pyrogenic effect of PGE is mediated by stimulation of cerebral cyclic AMP synthesis.