Acute heat stress and adrenal cortex: biochemical, histological and ultrastrureal study in albino rats

Stress can be defined as a state of threatened balance induced by external stressor and appear as the display of somatic, and psychic reaction, struggling to regain homeostasis. Among stressful stimuli, heat stress is an environmental factor capable of causing a wide range of physiological alteration chiefly at the level of the hopothalamic- pituitary-adrenocortical [HPA] axis. The objective of the present study was to evaluate the effect of acute heat exposure on the ACTH and cortisol levels as well as structurally and ultrastructurally changes of the adrenal cortical glands in rats. Twenty normal adult male albino rats, weighting 180-200 grams, were divided into two equal groups. Group A represented the control rats and group B acted as a heat stressed rats that were exposed to hear at 38-40[degree sign]C for sixty minutes. At the end of experiment, rats were anesthetized, blood sample withdrawn for hormonal study and suprarenal glands were dissected out and prepared for microscopical and ultrasctructural examinations. A significant increase in ACTH and cortisol levels were reported in heat stressed group when compared with control group. Light microscopic examination of suprarenal cortical layers of heat-stressed rats revealed foamy cytoplasm with pyknotic nuclear changes as compared to control rats. In addition, ultrastructure examination of group B showed mitochondrial changes in all zones especially zona reticularis, decreased number of lipid droplets in both zona fasciculate and reticularis, and prominent dilatation of smooth endoplasmic reticulum vesicles when compared with group A. In conclusion, acute heat exposure was a stressful condition affecting the suprarenal glands as evidenced by the altered biochemical hormonal levels along with both structural and ultra structural changes

Medicolegal aspects of deaths due to fatal traumatic heart injuries

Traumatic injuries account for the majority of unnatural deaths throughout the world with cardiac trauma being the leading cause of death among these victims. Understanding the mechanisms of injury as well as complications associated with cardiac trauma is important from both clinical and legal point of view. Traumatic cardiac injuries are considered one of the most commonly overlooked injuries in patient who died from trauma. This study aimed to investigate the cases of fatal traumatic heart injuries that had been received at morgue of Cairo during the period from January 1st 1996 to December 1st 2000. The aim was to find out the incidence of fatal traumatic heart injuries, the type of traumatic heart injuries, the causative agent, the manner of infliction in fatal traumatic heart injuries and if there is a pattern of fatal traumatic heart injuries, whether it could be possible to find out the risk factors of these injuries. In this study, the incidence of cardiac injury have constituted [183] 7.5% of all cases [2, 410] that were dissected in the same period of the study. The mean age of the cardiac injuries victims was 29.7 years. Male represent 167 [91.3%] of 183 cases whereas female represent 16 [8.7%] cases. Penetrating trauma form 171 [93.4%] of all cases, whereas blunt trauma have constitute 12 [6.6%] of all cases. The causes of cardiac injuries were: stabbing 140 [76.6%], firearm [shooting] 31 [16.9%], fall from height [5 = 2.7%], other blunt [5 = 2.7%] and traffic Accident [2 = 1.1%]. Knife was the main causal instruments represent 138 [75.5%]. Manner of death in fatal cardiac injuries was: homicide in 159 [86.9%] of cases, accidental in 15 [8.2%] of cases, suicidal in 8 [4.4%] of cases and undetermined in 1 [0.5%] of cases. The left ventricle was the most common wounded chamber. Represent 82 [44.8%] followed by right ventricles 60 [32.8%] then Right atrium 7 [3.8%] and lastly Left Atrium 2 [1.1%.] About 118 [64.5%] of cardiac injuries victims died at scene of crime and 22 [12.0%] during transportation whereas 43 [22.5%] reach hospital alive and then died. Regard Iry cases of death the isolated cardiac injury represent 157 [85.8%]. At the end of our study we noticed that cardiac Injuries are very important due to: high incidence low mean age of the victims and high prevalence of homicidal cases

Medicolegal aspects of maternal deaths of obstetrical origin

Understanding the extent of maternal deaths especially those due to medicolegal causes as homicide, suicide, accidents, illegal abortion and medical malpractice in women of childbearing age, may lead to improved identification of preventable problems that contribute to maternal morbidity and mortality. Maternal death due to unnatural [medicolegal] causes i.e. deaths due to violence, sudden and unexpected deaths, deaths due to medical malpractice and, in particular, those due to trauma- are increasing and forming the main causes of the maternal deaths. Maternal deaths due to natural causes i.e. direct or indirect obstetrical causes are decreasing nowadays, as a result of rapid progress in the methods of diagnosis and treatment of the various medical conditions affecting women during pregnancy, delivery and puerperium. Medical malpractice represented an important cause of the maternal deaths, especially with the development of the medical care standards. Because of this, if an accident happens the obstetrician more than any other doctor perhaps can find himself in the courts. To avoid this he has to know very well the causes of maternal mortality in order to avoid them as far as possible

Induction of apoptosis by aflatoxicosis and its modulation by ascorbic acid and sequential biochemical and histopathological changes in albino rats

Based on the DNA fragmentation profile in gel electrophoresis and histopathological and biochemical changes induced by acute toxicity of aflatoxin B1 [AFB1], this study aimed to clarify the protective effect of ascorbic acid [A.A.] on aflatoxicosis in albino rats. Forty rats were used in this work and divided into four groups, ten in each one. The 1st group was served as reference group [R-gr] where the rats in this group feed on basal diet only, rats of the 2nd group were given daily dose of ascorbic acid [A.A.] 300 mg/kg I.P. for three weeks, rats of the 3rd group were given single dose of AFB1 [1 mg/kg] I.P. after pretreated with daily dose of A.A. 300 mg/kg I.P, while rats of the last group were given single dose of AFB1 [1 mg/kg] I.P. after pretreated with daily dose of A.A. 300 mg/kg I.P. for three weeks. The results showed that acute aflatoxicosis induced DNA fragmentation pattern [DNA ladder] i.e. induced apoptosis, while no DNA fragmentation profiles were detected in the other three groups. The results also showed that AFB1 has a hepatotoxic and nephrotoxic effects as shown from the histopathological evaluation of liver and kidney and from the biochemical results very highly significant increase in serum levels of AST, ALT and ALP and the highly significant increase in serum creatinine and BUN levels

Electron microscopic study of the toxicological effects of sodium fluoride on lungs of adult albino rats

Since sodium fluoride [NaF] is implicated in the acute respiratory failure, the toxic effects of NaF ingestion on lung tissues were investigated. This experimental study was conducted on 40 adult albino rats. Experimental fluorosis was induced by daily oral administration of 18 mg/kg NaF for three successive months to twenty rats, while the other twenty rats were served as reference group with no medication. Electron microscopic study of the lung revealed injury of type I and II pneumocytes, haemorrhage, increase collagen fibers and apoptotic changes in alveolar macrophages in the form of fragmentation of nuclei. It was concluded that prolonged fluoride ingestion damages pulmonary tissues of rats

Immunohistochemical detection of alveolar macrophages and pulmonary giant cells and their diagnostic value in some types of asphyxia

The occurrence of numerous alveolar macrophages and pulmonary giant cells has been reported in both fatal asphyxia and other causes of death Pulmonary giant cells as a significant diagnostic tool in cases of asphyxia is still a controversial discussion. In the present study we investigated experimentally some types of asphyxia to detect both alveolar macrophages and pulmonary giant cells by immunohistochemical method using a monoclonal antibody Ki-Mlp, and to estimate the frequency,. of these cells microscopically in each group examined to evaluate the statistical differences which may help in differentiation between the various causes of death from asphyxia. Forty two adult albino rats were divided into 7 groups each contained 6 animals. The first group were sacrificed by decapitation and act as a control group. The animals of the 2nd and 3rd. groups were killed by obstructive asphyxia as strangulation and hanging respectively, while those of the 4th group were asphyxiated by drowning. The 5th 6 th and 7th groups included deaths of asphyxia due to inhalation of irritant gases as methanol either and butagaz respectively. Serial sections were prepared from formalin-fixed paraffin-embedded tissue specimens of lungs and brains, and were used for Hx and E and immunostaining. Alveolar macrophages and pulmonary giant cells in all groups of asphyxia stained positively with a monoclonal antibody Ki-Mlp. The frequency of these reactive cells showed a variation between the different types of asphyxia which may be useful in. the differentiation between the asphyxiated cases as this immunostaining method was easily and rapidly performed. No histiocytes could be observed in the brain tissues which served as a good negative control

Cardiotoxic and genotoxic effects of doxorubicin in albino rats

Doxorubicin [DXR] is a potent chemotherapeutic agent used in the treatment ofneoplastic diseases. To evaluate its cardiotoxicity and genotoxicity, it wasadministered orally for three successive weeks [three days a week] at a dailydose of 3.6 mg/kg body weight to a group of normal adult albino rats. At theend of the experiment, examination of the cardiac muscle of the treated ratsby light microscopic process showed areas of myocardial damage with separatedfoci of degenerated fibers, dilatation of blood vessels with increasedvasculature and areas of vascular degenerative changes between separatedirregular myofibrils. Electron microscopic study revealed, in addition to the above changes, a partial loss of myofibrils in some areas and degeneration in others, besides a disorganization of the nuclear membrane with nucleolusalternation and distension of blood capillaries. Increased vasculardegeneration and alternation of the interlocated discs were noted in manyareas with increased glycogen particles in-between the myofibrils. DXRinduced structural chromosomal aberration in the form of increased breaks andring chromosome formation, deletion of the short arm of acrocentricchromosome, and duplication of the long arm of metacentric chromosome, whilethe main numerical aberration was polyploidy chromosomal pattern

Light and electron microscopic studies of rabbit lungs in fresh water drowning and near-drowning

This study was designed to investigate the light and electron microscopic changes which occur in the lung of the rabbit in case of drowning and near-drowning. Thirty male healthy adult rabbits were used in this work. They were divided into three equal groups. The first group was used as a control group. The second group was anesthetized and endotracheal tube was introduced and 6 ml/kg of fresh water was instilled into the endotracheal tube. The animals were sacrificed after 29 minutes. The third group was also anesthetized and intubated, and fresh water was instilled into the endotracheal tube. Specimens from the lungs of the three groups were taken and processed for both light and electron microscopic processes. The results showed mainly vascular damage in near-drowning and marked alveolar cell damage in case of drowning

Toxicological impact of lead and/or rodenticide diphacinone I. Changes in bleeding time, body weight, amino acid and protein contents and food and water consumption in albino rats

An observable depression in food consumption accompanied with a decrease of body weight were noticed in animals exposed to lead in various time intervals of the study. Water consumption showed a decrease in initial periods of exposure to lead but it tended to elevate by the 4[th] week of intoxication. This parameter also decreased during the period of diphacinone group and of lead treated animals followed by diphacinone were higher than those of the control group, however liver weights of both treated groups decreased compared to those of controls. Kidney weight did not change due to treatments. Bleeding time increased through the later periods of lead acetate treatment. Exposure of animals to diphacinone preceded by lead acetate for 4 weeks caused futher increase in the bleeding time compared to control or lead treated groups. Animals treated with only diphacinone showed an elongate bleeding time which was longer than those of other experimental groups. Total protein contents decreased significantly in the liver kidney and brain during the second week of intoxication. In contrast serum showed substantial elevations especially during the initial periods of the treatment. Amino acid analysis indicated a general initial decrease in various organs followed by marked elevations by termination of the experiment