Behavioral state-specific changes in human hippocampal theta activity

Although there has been extensive examination of the behavioral and physiologic correlates of hippocampal theta activity in animals, the human literature consists of a single case study. We investigated the differential effects of four behavioral states on human hippocampal theta activity in 16 epilepsy surgery patients. Behavioral conditions included resting eyes closed (RC), resting eyes open (RO), eyes open with auditory word activation (AW), and eyes open with visuospatial activation (VS). Hippocampal theta activity decreased during both RO and VS compared to both RC and AW. There were reciprocal changes in delta activity. Comparisons of RO to VS and of RC to AW were nonsignificant. The results demonstrate state-specific changes in human hippocampal theta and are consistent with the animal literature that relates hippocampal theta to sensorimotor integration and forebrain volitional mechanisms.     

Short and middle latency vestibular evoked responses to acceleration in man.

We have succeeded in recording short and middle latency vestibular evoked responses in human subjects. The head was held rigidly in a special, patented head holder, constructed individually for each subject, which gripped the teeth of the upper jaw. The stimulus consisted of 2/sec steps of angular acceleration impulses produced by a special motor with intensities of about 10,000 degrees/sec 2 and with a rise time of 1-2 msec. The electrical activity was recorded as the potential difference between special forehead and mastoid electrodes having a large, secure contact area with the skin. The activity was digitally filtered and averaged in 2 separate channels by means of a Microshev 2000 evoked response system. The short latency responses, with peaks at about 3.5 msec (forehead positive), 6.0 msec (forehead negative) and 8.4 msec (forehead positive; bandpass: 200-2000 Hz; average of 1024 trials), had amplitudes of about 0.5 microV. The middle latency responses had peaks at about 8.8 msec (forehead positive), 18.8 msec (forehead negative) and 26.8 msec (forehead positive; 30-300 Hz; N = 128 trials), with larger amplitudes (about 15 microV). These responses were consistently recorded in the same subject at different times and were similar in different normal subjects. Strenuous control experiments were conducted in order to ensure that these responses are not artefacts due to the movement of conducting media (head, electrodes and leads) in the electromagnetic field of the motor and are elicited by activation of normal labyrinths.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oral health of individuals aged 3-80 years in J?nk?ping, Sweden in 1973 and 1983. I. A review of findings on dental care habits and knowledge of oral health

The aim of the present study was to present data from dental care habits and knowledge of oral health in two cross-sectional studies carried out in 1973 and 1983. A random sample of approximately 1000 individuals evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60 and 70 years was studied for each of these two years. In the 1983-year examination 80 individuals 80 years of age were also included. All subjects were inhabitants of the community of J?nk?ping, Sweden. A questionnaire about dental care habits and knowledge was used in combination with a clinical and radiographical examination. The participants answered 23-101 questions. The same questions were raised in 1973 and 1983. For most age groups more then 80 per cent visited a dentist yearly in 1983. This yearly attendance was higher than that for 1973. In the 20-year-old group 14 per cent of the individuals received dental care in the PDS in 1973 compared to 63 per cent in 1983. The main reason to visit a dentist in 1973 was by the patient's own initiative while in 1983 the appointments were based on the dentist's initiative. The number of subjects that felt discomfort in connection with a visit to the dentist had decreased between 1973 and 1983. Knowledge about the etiology of caries had increased between 1973 and 1983 was not the case for gingivitis and periodontitis. An increase had occurred in toothbrushing frequency and the use of toothpicks and disclosing tablets but this between 1973 and 1983. In 1983, 98 to 93 per cent of the subjects in the age groups 10-30 years had been exposed to topical fluorides. The corresponding figure for 30-year-olds in 1973 was 1 per cent. It is obvious that during the period 1973 to 1983 there has been an increase in dental attendance, knowledge of dental diseases, oral health and the use of preventive measures.     

Non-endemic Burkitt's lymphoma

Burkitt's lymphoma, characterized by jaw and abdominal tumors, is the most common early childhood malignancy in Central Africa and well-known in the United States, with only sporadic reports coming from other countries. Considered to be the fastest growing tumor in man, it is thought to be of viral etiology with warm, humid climate and malaria regarded as co-factors. This is the first case of Burkitt's lymphoma reported from Greece.     

Rapid, competitive enzymoimmunoassay for albumin in urine

In this solid-phase competitive enzymoimmunoassay for albumin in human urine, antiserum to human serum albumin labeled with horseradish peroxidase (EC 1.11.1.7) is incubated with solid-phase-bound human serum albumin in the presence of sample or standard. Results obtained correlate well (r = 0.96) with those of an established fluoroimmunoassay. The present assay covers the range 0.9 to 200 mg/L and can be performed within 1 h. These characteristics, together with the simplicity of the assay protocol, make it very useful for monitoring low concentrations of albumin in urine. Detection of such minimal albuminuria allows initiation of therapy that may prevent development of clinical proteinuria and associated diabetic nephropathy.     

Necrosis of the femoral head following fracture of the femoral neck

One hundred and thirty fractures of the femoral neck treated with sliding screw-plate or sliding nail-plate were followed for up to 65 months postoperatively. Throughout the observation period the yearly incidence of necrosis of the femoral head was between 5 and 10 per cent, as estimated by the life table method, and after 5 years 37 per cent of the patients with united fractures had developed necrosis of the femoral head. The cases of necrosis were all characterized radiographically by one or more areas of subchondral cortical depression, generalized subchondral fragmentation or isolated patches of sclerosis. It is concluded that estimation of the frequency of femoral head necrosis after fracture of the femoral neck requires long-term follow-up and reliable, reproducible radiographical criteria for necrosis of the head. Because of the high mortality of patients sustaining these fractures, statistical methods employing censored data should be used.