Heat stroke: opioid-mediated mechanisms

In our previous study in guinea pigs, intensive and prolonged intraperitoneal heating (IPH) caused heat stroke characterized by high mortality and accompanied by two paradoxical phenomena: ear skin vasoconstriction at a high body temperature (Tb) (hyperthermia-induced vasoconstriction) and a post-IPH Tb fall at an ambient temperature (Ta) below thermoneutrality (hyperthermia-induced hypothermia). In this study, we tested the hypothesis that the mechanisms of the two phenomena involve endogenous opioid agonists. Experiments were conducted in 24 unanesthetized, lightly restrained guinea pigs, each chronically implanted with an intraperitoneal thermode and intrahypothalamic thermocouple. The thermoregulatory effects of a wide-spectrum opioid-receptor antagonist, naltrexone (NTX; 50 or 0 mumol/kg sc), were studied in IPH-induced heat stroke and under normal conditions. IPH was accomplished by perfusing (50 ml/min; 80 min) water (45 degrees C) through the thermode. Ta was maintained at approximately 24 degrees C. Skin vasodilation occurred at the onset of IPH but later changed to vasoconstriction despite high Tb and continuing IPH. IPH-induced hyperthermia (1.8 +/- 0.1 degrees C) was followed by a post-IPH Tb fall (-5.1 +/- 0.7 degree C; calculated for the survivors only). The 48-h mortality rate was 50%. NTX prevented the hyperthermia-induced vasoconstriction and attenuated the hyperthermia-induced hypothermia (-1.8 +/- 0.4 degree C). None of the NTX-treated animals died. The effects of NTX on Tb regulation under normal conditions were minor. These results indicate that the phenomena of both hyperthermia-induced vasoconstriction and hyperthermia-induced hypothermia are opioid dependent. The latter is speculated to reflect opioid-mediated inhibition of metabolism; the former is thought to result from opioid-induced hemodynamic alterations. Because both phenomena did not occur in the NTX-treated survivors, the skin vasoconstriction at high Tb and the posthyperthermia Tb fall may be viewed as markers of the severity of heat stroke. It is suggested that opioid antagonists may have therapeutic potential in heat-induced disorders.     

Heat stroke and fluphenazine therapy: report of a case

A fatal case of heat stroke in a 21-year-old man with chronic schizophrenia is reported. Phenothiazine therapy is thought to have been a factor of major importance in the induction of this syndrome. These cases may become the responsibility of the medical examiner, and the importance of obtaining a complete drug history is stressed.     

Glomus tympanicum in infancy

A glomus tympanicum tumor, limited to the cochlear promontory, was excised from the middle ear of a 6-month-old girl. To our knowledge, there have been no reports of temporal bone paragangliomas occurring at a younger age. Diagnosis, therapy, and the special characteristics of pediatric glomus tumors are discussed.     

Topiramate efficacy in infancy

Syncytial giant cell hepatitis is a severe form of hepatitis characterized by diffuse giant cell transformation of hepatocytes. The disease may evolve to chronic cholestatic cirrhosis necessitating liver transplantation. We report the case of an adult liver transplant recipient presenting with early recurrent disease without concomitant clinicobiochemical syndrome. Early recurrence of giant cell hepatitis after liver transplantation favors the hypothesis of a transmissible agent as the etiology of the disease. Routine follow-up liver biopsy is necessary in these cases in order to gain more information about the precise incidence and aggressivity of disease recurrence in the allograft.     

Scimitar syndrome in infancy

OBJECTIVES: The objectives of this study were to determine the anatomic and physiological factors most responsible for the severe symptoms and poor prognosis of infants with scimitar syndrome. BACKGROUND: Whereas the diagnosis of scimitar syndrome is often made incidentally in older children and adults who undergo chest radiography for diverse reasons, infants in whom the diagnosis is made typically present with severe symptoms and have a poor prognosis. METHODS: The clinical, catheterization and imaging data of 13 consecutive infants with scimitar syndrome who underwent cardiac catheterization in the 1st 6 months of life were reviewed, with emphasis on the pulmonary artery pressure, pulmonary and cardiovascular anatomy, therapeutic interventions and outcome. RESULTS: Twelve of the 13 infants had pulmonary hypertension at the time of diagnosis. Six patients died despite specific treatment. Eleven of 13 infants had associated cardiac malformations and 9 had large systemic arterial collateral channels to the right lung. Seven patients had anomalies involving the left side of the heart, especially varying degrees of hypoplasia of the left heart or aorta, and six of these patients died. Ten patients underwent surgical or transcatheter therapy in the 1st year of life. Systemic arteries to the right lung were ligated in three patients and occluded by transcatheter embolization in four. Balloon angioplasty was carried out in two patients, one with stenosis of the left-sided pulmonary veins and one with stenosis of the anomalous right pulmonary vein. The latter had placement of a balloon-expandable stent. In both patients, pulmonary vein stenosis progressed. Six patients had surgical repair of associated cardiovascular anomalies, and two required repair of extracardiac congenital anomalies. Occlusion of the anomalous systemic arteries was generally associated with clinical improvement, but congestive heart failure and pulmonary hypertension recurred in those patients with associated cardiovascular anomalies, whose condition subsequently responded after correction of the shunt lesions. CONCLUSIONS: The severe symptoms and pulmonary hypertension found in infants with scimitar syndrome have many causes. Anomalous systemic arterial supply, pulmonary vein stenosis and associated cardiovascular anomalies play a significant role, and the ultimate outcome of individual infants depends on the feasibility of treating these anomalies in early infancy.     

Paracetamol poisoning in infancy

An eight-week old infant with alcohol embryopathy, weighing 3,700 g, was found to have abnormal liver functions (GPT 312 U/l, Quick value 25%) after surgical repair of a stenosis of the left ureter at its origin. The hospital notes indicated that the infant had been given a total of 1.6 g paracetamol over 60 hours for postoperative restlessness and pain. The serum paracetamol level was 60 mg/l 8 hours after the last dose of the drug. Blood exchange transfusion lowered the paracetamol level to 11 mg/l within 14 hours. After the exchange transfusion further signs of poisoning, namely renal impairment and a severe encephalopathy were noted, and Candida was demonstrated in urine, tracheal secretion and ascites. The renal and hepatic damage proved reversible under symptomatic treatment. But the child, now 1 year old, is severely retarded mentally and in its motor functions. These sequelae may be a residue of the paracetamol poisoning, complications of the clinical course or a combination of the two.     

Self-perception and action in infancy

By 2-3 months, infants engage in exploration of their own body as it moves and acts in the environment. They babble and touch their own body, attracted and actively involved in investigating the rich intermodal redundancies, temporal contingencies, and spatial congruence of self-perception. Recent research is presented, which investigates the spatial and temporal determinants of self-perception and action infancy. This research shows that, in the course of the first weeks of life, infants develop an ability to detect intermodal invariants and regularities in their sensorimotor experience, which specify themselves as separate entities agent in the environment. Recent observations on the detection of intermodal invariants regarding self-produced leg movements and auditory feedback of sucking by young infants are reported. These observations demonstrate that, early in development and long before mirror self-recognition, infants develop a perceptual ability to specify themselves. It is tentatively proposed that young infants' propensity to engage in self-perception and systematic exploration of the perceptual consequences of their own action plays an important role in the intermodal calibration of the body and is probably at the origin of an early sense of self: the ecological self.     

Maternal language in infancy.

Observations of 36 preterm infants and their English-speaking mothers suggest that maternal language to the infant varies as a function of the age and ordinal position of the infant and maternal education. The relationship between maternal language at 1 mo of age and the mother's verbal style to her older infant allows for early identification of maternal language input styles and, therefore, has important implications for mother–infant intervention programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies in inductive inference in infancy

Imitation of events was used to explore the inductive generalizations that 14-month-olds have made about animals, vehicles, and household artifacts. In Experiment 1 infants generalized domain-specific properties such as drinking to animals but not to vehicles, whereas they generalized domain-neutral properties such as going into a building to exemplars from both domains. The next four experiments showed that infants tend to interpret animal events very broadly, for example, construing a dog merely as a land animal rather than as a differentiated kind in its own right. Infants were somewhat more selective in their construals of vehicles. Experiment 6 showed that 14-month-olds also generalize "basic-level properties" very broadly. For example, they chose a pan to demonstrate drinking almost as often as a cup and fed a bone to a bird as often as to a dog. By 20 months, their selections narrowed appropriately for artifacts, but were still overgeneralized for natural kinds. The experiments indicate that infants tend to generalize their early experiences broadly across domains, often across exemplars that have a variety of different surface characteristics. The data suggest that it is the conceptual meaning of objects, rather than their physical features, that controls early associative learning.     

Individual differences in emotionality in infancy

In this multimethod investigation of early emotionality, we observed 112 8- to 10-month-olds' responses to standard procedures consisting of multiple brief episodes that elicited joy, fear, anger, and discomfort to aversive stimulation. We obtained parental reports about the infants' temperament and observed their emotional tone during naturalistic interactions with their mothers. Parameters of emotional response to the standard procedures (latency, discrete behaviors, and average and peak intensity across facial, vocal, and bodily channels) cohered strongly within each episode. To a lesser extent and with the exception of anger, they also cohered across episodes targeting the same emotion. The four emotions appeared orthogonal, except for the peak intensity of response, which cohered modestly across the 3 negative emotions. The emotionality measures converged to some extent: responses to the standard procedures and father-reported temperament related meaningfully to the infant's emotional tone in mother-child interactions. As predicted, infants' capacity for focused or effortful attention was modestly associated with better modulated negative emotionality.     

Ruptured left ventricular diverticulum in infancy

Congenital diverticulum of the left ventricle is rare, and rupture of such a diverticulum is even more rare. We describe successful surgical repair of a ruptured left ventricular diverticulum in an 11-month-old infant.     

Hydrocele and testicular tumors in infancy

A long-term schistosomiasis control programme was initiated on Pemba Island, Tanzania in 1986 with the aim of eliminating morbidity due to Schistosoma haematobium infection. The programme used haematuria as a community indicator of morbidity for surveillance and for identifying individuals for selective population chemotherapy. Analysis of the first 3 evaluation studies showed that the prevalence of microhaematuria was linearly related to the prevalence of infection, and that visually detectable haematuria was a marker of the intensity of infection and risk of morbidity in a community. These relationships remained consistent during repeated community-based chemotherapy, suggesting that measures of haematuria may be useful tools for surveillance.     

Sexology of ictal masturbation in infancy

In 1952, under the title of "Masturbation in Infants," Bakwin reported three cases of females all younger than one year of age. Bakwin's type of so-called masturbation has been considered in the differential diagnosis of epilepsy in several papers published since 1975. The cases reported display a great similarity and underscore an ictal explanation of the syndrome.     

Learning about tools in infancy.

These experiments explored the role of prior experience in 12- to 18-month-old infants' tool-directed actions. In Experiment 1, infants' use of a familiar tool (spoon) to accomplish a novel task (turning on lights inside a box) was examined. Infants tended to grasp the spoon by its handle even when doing so made solving the task impossible (the bowl did not fit through the hole in the box, but the handle did) and even though the experimenter demonstrated a bowl-grasp. In contrast, infants used a novel tool flexibly and grasped both sides equally often. In Experiment 2, infants received training using the novel tool for a particular function; 3 groups of infants were trained to use the tool differently. Later, infants' performance was facilitated on tasks that required infants to grasp the part of the tool they were trained to grasp. The results suggest that (a) infants' prior experiences with tools are important to understanding subsequent tool use, and (b) rather than learning about tool function (e.g., hammering), infants learn about which part of the tool is meant to be held, at least early in their exposure to a novel tool. (PsycINFO Database Record (c) 2010 APA, all rights reserved)