Medical residence in pediatrics: in the field of practice

The study focuses on how specificity of pediatric practice at the Fernandes Figueira Institute, Oswaldo Cruz Foundation, contributes to the development of clinical reasoning, the ability to detect evolution in serious illness, and the capacity to use diagnostic and therapeutic techniques. Data were collected using a thematic interview and analyzed by a semiotic model. The results showed a common view of medicine as both science and art, the doctor-patient relationship as legitimating medical knowledge, pediatrics as having its own peculiarities (thus being defined as a medical specialty), and a severity postulate that hinders the development of clinical reasoning and thus the ability to detect evolution in serious illness.     

Giant cavernous angioma: report of two cases

Cavernous angiomas or haemangiomas or yet cavernomas are malformations of the central nervous system classified as occult vascular brain lesions. These rare lesions are clinically silent. They are defined by the presence of abnormally large vascular cavities or sinusoids channels of variable size, with sharp walls, located inside but not invading the brain parenchyma. They can occur at any age, including the neonatal period. Most of the small lesions are located inside the brain parenchyma. No abnormal circulation can be demonstrated in angiography and CT scan can be helpful for diagnosis only in rare occasions. Magnetic resonance is the best exam to demonstrate the lesion. Despite the benign character some lesions may cause neurologic dysfunction when their removal may be difficult. Complete extirpation is the best treatment if the lesion is favorable located and is causing neurological dysfunction. Two cases of giant cavernomas with good outcome after total removal are present. Only three cases of giant cavernomas were reported in the literature.     

Reversible posterior encephalopathy syndrome: case report

The posterior reversible leukoencephalopathy syndrome (PRES) is a recently proposed cliniconeuroradiologic entity.The most common causes of PRES are hypertensive encephalopathy, eclampsia, cyclosporin A neurotoxicity and the uremic encephalopathies.Most patients are markedly hypertensive at presentation, although some have only mildly elevated or even normal blood pressure. Symptoms may include headache, nausea, vomiting, altered mental status, seizures,stupor, and visual disturbances. On CT and MR studies, edema has been reported in a relatively symmetrical pattern, typically in the subcortical white matter and occasionally in the cortex of the occipital and parietal lobes. These often striking imaging findings usually are resolved on follow-up studies obtained after appropriate therapy. Diffusion-weighted images would not show hyperintense signal because of the presence of interstitial rather than cytotoxic edema. We report a case of PRES due to hypertensive encephalopathy studied by CT and MRI.     

Drugs of Abuse, Immune Modulation, and AIDS

Illicit drugs such as amphetamines, cocaine, marijuana, and opiates alter immune function and decrease host resistance to microbes in vitro and in experimental animal models. Effects on the immune system may be mediated indirectly as a result of drug interactions in the central nervous system (CNS) or directly through activation of cognate receptors on various immune cell types. For marijuana and opioids, seven-transmembranal G protein-coupled receptors have been identified in the CNS and in the immune system that may play a functionally relevant role in immune modulation. There is accumulating evidence that sigma₁ receptors play a comparable role in cocaine-mediated alteration of immune responses. A mode by which these exogenously introduced substances affects immunity and host resistance may be by perturbing the balance of Th₁ proinflammatory versus Th₂ anti-inflammatory cytokines and lipid bioeffectors. However, while illicit drugs have been documented to alter immune functions in vitro and in animal models, there is a paucity of controlled longitudinal epidemiological studies that definitively correlate immunosuppressive effects with increased incidence of infections or immune disorders in humans, including infection with the human immunodeficiency virus (HIV) or disease progression to AIDS.     

Cannabinoid-Induced Immune Suppression and Modulation of Antigen-Presenting Cells

The study of marijuana cannabinoid biology has led to many important discoveries in neuroscience and immunology. These studies have uncovered a new physiological system, the endocannabinoid system, which operates in the regulation of not only brain function but also the regulation of the immune system. Studies examining the effect of cannabinoid-based drugs on immunity have shown that many cellular and cytokine mechanisms are suppressed by these agents leading to the hypothesis that these drugs may be of value in the management of chronic inflammatory diseases. In this report, we review current information on cannabinoid ligand and receptor biology, mechanisms involved in immune suppression by cannabinoids with emphasis on antigen-presenting cells, and preclinical and clinical models analyzing the therapeutic potential of cannabinoid-based drugs.     

Exposure to different intrauterine environments: implications for telomere attrition in early life

Objective: Studies focusing on telomere attrition in newborns and what factors could be involved in this issue are sparse; most reports have been in adult populations. Thereby, the aim of this study was to present an overview of what is currently known about the relationship between environmental exposure of the fetus during pregnancy and telomere length outcomes in early life.

Methods: The MEDLINE (via PubMed) and Bireme databases were searched for studies published until 1 June 2016. Studies that reported telomere length measurement from birth to age 1 year were included.

Results: Fifteen articles were selected that evaluated possible relationships between maternal smoking, hyperglycemia, hypertension, sleep apnea, psychological stress, folate concentration in early pregnancy, and radiation, in addition to small-for-gestational-age status and preterm birth. We found that sleep apnea, psychological stress, and folate concentration in early pregnancy were associated with telomere shortening in the newborn. No association was found with radiation, small-for-gestational-age status, or preterm birth. Results for maternal smoking, hyperglycemia, and hypertension were conflicting, and further studies should be considered.

Conclusion: The actual clinical implications of these findings have yet to be investigated.     

The roles of age at treatment and dose in carcinogenesis in C3Hf/Dp mice with a single administration of N-nitroso-N-methylurea.

C3Hf/Dp mice were given a single i.p. injection of 50, 25 or 5 mug/g N-Nitroso-N-Methylurea (NMU) at either 1 or 70 days of age or 50 mug/g at 21 days of age. They were observed until death or until 120 weeks of age. The two highest doses of NMU produced tumours in a wide spectrum of organs, including the thymus, forestomach, lung, liver (only in males), kidneys, ovaries and orbital glands. The only two tumour types which appeared to be closely related to the occurrence of death were thymic lymphomata (most of which were found in mice dying before 40 weeks after treatment) and carcinomata of the forestomach. Lifetime analyses are presented concerning the occurrence of these two tumour types as well as the occurrence of any tumour after 40 weeks of age or since treatment. Incidences of thymic lymphomata were 67.6%, 39.0% and 21.2% in mice receiving 50 mug/g NMU at 1, 21 and 70 days respectively and 17.1% in mice receiving 25 mug/g at 1 day. In the other groups the incidence of thymic lymphomata was zero or negligible. The rate of progression of thymic lymphomata until death was related to both earliness of treatment and dose. On the contrary, incidences and progression of carcinomata of the forestomach were unrelated to age at treatment. Since breakdown of NMU is very rapid and does not require enzymes, these results are considered as evidence that host-tumour interaction differs from organ to organ. No excess of tumours over the controls was found in mice receiving 5 mug/g either at 1 or 70 days of age.     

Experimental carcinoma of liver in macaque monkeys exposed to diethylnitrosamine and hepatitis B virus.

The effects of treatments with diethylnitrosamine (DENA) and hepatitis B virus (HBV) on macaque monkeys were investigated by virus serology and by light and electron microscopy. The experimental groups comprised 43 newborn or juvenile cynomolgus and rhesus monkeys of both sexes. HBV neither had a carcinogenic effect nor increased the oncogenic effect of DENA. However, HBV given to juvenile primates before treatment with DENA resulted in subsequent gross and microscopic alterations consistent with mild hepatitis and postnecrotic cirrhosis; multifocal liver carcinoma apparently developed within these cirrhotic nodules. The pathologic findings in the experimental animals were strikingly similar to those observed in liver cancer patients.