Assessing the temporal reproducibility of human esophageal motor-evoked potentials to transcranial magnetic stimulation.

BACKGROUND: Although the electrophysiological properties and reproducibility of somatic limb motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) are well characterized, little is known about the reproducibility of MEPs for viscerosomatic structures such as the esophagus. AIM: To determine the temporal reproducibility of esophageal MEPs to TMS. METHODS: MEPs to TMS were recorded from the proximal esophagus, using a swallowed catheter housing a pair of electrodes, in eight healthy subjects at five stimulus intensities (SI) (motor threshold [MT] to 20% above MT). For each SI, 20 consecutive TMS stimuli at 5-second intervals were delivered over a single scalp site (dominant hemisphere at site exhibiting MT at lowest SI) and repeated 40 and 80 minutes thereafter. MEP amplitudes and latencies were measured, and means were sequentially calculated for each SI and then log-transformed. The repeatability coefficients (RC) for the three time points were calculated across each set of 20 stimuli and presented as an exponential ratio. RESULTS: Best RC (amplitude/latency) were achieved at 120% SI relative to MT, being 1.8/1.2 (optimal = 1.0). For lower intensities of 115%, 110%, 105%, and 100% SI, the RC were 2.1/1.2, 2.1/1.1, 2.4/1.2, and 2.6/1.4, respectively. For all SI, the greatest reductions in RC occurred over the first 10 stimuli, with little additional gain beyond this number. CONCLUSIONS: Latencies of esophageal MEP to TMS across intensities are highly reproducible, whereas amplitudes are more stimulus intensity-dependent, being most reliable and reproducible at the highest stimulus strengths. SIGNIFICANCE: Using careful parameters, TMS can be used reliably in future studies of viscerosomatic structures, although the size of the response variability needs to be taken into account when assessing changes in cortico-fugal activity.

Association between parental and student smoking behaviour in a Brazilian medical school.

In a 20% random sample of University of Brasilia medical students no association was found between student and parental smoking behaviour. A low prevalence of habitual smoking (14.0%) and a low mean daily cigarette consumption (8.9 cigarettes per smoker, per day) characterized this population.

Effects of intrauterine growth and gestational age upon infants' early psychomotor development in Brazil.

In a sample of 245 Brazilian infants, the effects of intrauterine growth and gestational age upon psychomotor development were studied through ages 4 to 18 mo. Gestational age was more important than intrauterine growth in determining psychomotor development in the first 18 mo. of life. Intrauterine growth had a significant but smaller and more stable effect than gestational age upon psychomotor development at all ages. Maternal parity, interval between the birth of the child studied and the next oldest sibling, 5-min. Apgar score, and socioeconomic status were also relevant to psychomotor development at these early ages.

Is motor development really more advanced in Third World infants?

Motor and adaptive development were studied longitudinally at 4, 8, 12, and 18 mo. in Brazilian infants of low and middle socioeconomic status. No significant differences were found between these two groups. Gesell Developmental Quotients were similar to those found in American infants, which did not confirm precocious motor development in Brazilian infants.

Making sense of the hair zinc literature: where do we go from here?

The authors make a critical review on the hair zinc literature, discussing the main contributions in this field. Certain explanations, as well as some solutions aimed to put an end to the confusion which exists on this matter are suggested. As a first step, it is recommended that only endogenous zinc in hair be reliably measured. Therefore, the zinc metabolic status should be operationally defined in function of the zinc detected in hair. Each one of the variables should thus be identified, quantified and controlled. It must be added that these variables would have to include differences in zinc metabolism. Only then would it be possible to see the real baseline reference value of hair zinc. At present researchers should begin looking for a functional relation and not just a statistical significant association between hair zinc concentration and zinc metabolic status. At the same time, it would be necessary to ratify and prove findings of the great number of studies reported in the paper, through the replication of studies with experimental animals.

Psychophysiological responses to visceral and somatic pain in functional chest pain identify clinically relevant pain clusters.

BACKGROUND: Despite chronic pain being a feature of functional chest pain (FCP) its experience is variable. The factors responsible for this variability remain unresolved. We aimed to address these knowledge gaps, hypothesizing that the psychophysiological profiles of FCP patients will be distinct from healthy subjects. METHODS: 20 Rome III defined FCP patients (nine males, mean age 38.7 years, range 28-59 years) and 20 healthy age-, sex-, and ethnicity-matched controls (nine males, mean 38.2 years, range 24-49) had anxiety, depression, and personality traits measured. Subjects had sympathetic and parasympathetic nervous system parameters measured at baseline and continuously thereafter. Subjects received standardized somatic (nail bed pressure) and visceral (esophageal balloon distension) stimuli to pain tolerance. Venous blood was sampled for cortisol at baseline, post somatic pain and post visceral pain. KEY RESULTS: Patients had higher neuroticism, state and trait anxiety, and depression scores but lower extroversion scores vs controls (all p < 0.005). Patients tolerated less somatic (p < 0.0001) and visceral stimulus (p = 0.009) and had a higher cortisol at baseline, and following pain (all p < 0.001). At baseline, patients had a higher sympathetic tone (p = 0.04), whereas in response to pain they increased their parasympathetic tone (p ≤ 0.008). The amalgamating the data, we identified two psychophysiologically distinct 'pain clusters'. Patients were overrepresented in the cluster characterized by high neuroticism, trait anxiety, baseline cortisol, pain hypersensitivity, and parasympathetic response to pain (all p < 0.03). CONCLUSIONS & INFERENCES: In future, such delineations in FCP populations may facilitate individualization of treatment based on psychophysiological profiling.

Prematuridade e o peso ao nascer no relacionamento mae-filho. / Prematurity and low birth weight in mother-child relations

O estimulo do recem-nascido e tao importante na determinacao da aceitacao materna quanto e a aceitacao materna na sobrevivencia e desenvolvimento do filho. O valor-estimulo do recem-nascido prematuro ou de baixo peso para idade gestacional torna a aceitacao materna mais dificil quando nao apresentam as caracteristicas robustas esperadas. A aceitacao materna foi investigada em 132 casos de maes de recem-nascidos a termo, prematuros e de baixo peso. Uma diferenca significativa foi encontrada entre a aceitacao materna das criancas a termo de peso normal e os prematuros e de baixo peso

Adaptacao psicologica de criancas com cancer. / The psychological adaptation of children with cancer

Dezenove criancas, pacientes do Ambulatorio de Oncologia do Servico de Cirurgia Pediatrica da Universidade de Brasilia, foram estudadas longitudinalmente. A amostra inclui criancas ainda em tratamento e criancas que ja o terminaram. Cinco dimensoes de adaptacao psicologica foram analisadas: capacidade cognitiva, relacionamento familiar, relacionamento fora da familia, preocupacao com a doenca e comportamento atual. Em geral, o prognostico para o desenvolvimento psicologico dessas criancas foi favoravel e parece depender mais de outras variaveis do que da propria experiencia de ter tido cancer. Os fatores mais importantes para o prognostico psicologico foram o nivel educacional dos pais, a situacao socio-economica da familia e problemas de relacionamento intrafamilar ja existentes antes da doenca. Foi observado tambem que, em relacao ao desenvolvimento psicologico, criancas com menos de dois anos de idade foram mais prejudicadas do que criancas maiores