Implicit motor learning is impaired in strabismic adults.

Binocular vision disorders (BVD) are quite common in subjects with cerebellar dysfunctions. Also individuals with strabismus often suffer from many motor deficits, such as impaired body balance and walking. It is known that the cerebellum is necessary to maintain proper body posture but also to learn motor skills. It is conceivable that subjects with BVD would also have deficits in procedural (implicit) motor learning, one of the primary cerebellar functions. The primary aim of this study was to explore motor learning abilities in subjects with BVD (strabismic group, SG). Modified versions of a single reaction time task were used in the scheme proposed by Molinari et al. in 1997. A set of three different tasks (Experiment 1) were performed under dominant eye viewing to investigate (a) procedural (implicit) motor learning, (b) declarative (explicit) learning, and (c) simple stimulus-response associative learning. Because each task examined different aspects of motor learning abilities, it could be revealed which motor learning pathway is impaired in SG. Results showed that the SG had slower reaction times in all three tasks and demonstrated poor implicit motor learning ability compared to controls. To verify if these results were caused by reduced binocular vision or cerebellar deficits, per se, a nonstrabismic binocular anomalies group (NSG) was introduced, and all the same tests were performed (Experiment 2). These results revealed that there were no differences between the NSG and the control group with good binocularity. To conclude, the poor procedural learning ability and slower reaction times in strabismic subjects should not be explained as an effect of incomplete binocular vision that influences the maturity of the visual cortex and transformation of visual information into a motor program because binocular anomaly individuals without strabismus have motor learning abilities close to the controls. Some cerebellar deficits appear to be the origin of observed anomalies.

Coincidence and awareness of oral parafunctions in college students.

OBJECTIVE: The aim of the study was to determine the prevalence and awareness of particular types of oral parafunctions in young healthy students and any association with temporomandibular disorders (TMD). MATERIAL AND METHODS: The study was performed in a randomly selected group of 303 healthy students (mean age 18.8 years) from the vocational technical school in Wroclaw, Poland, who underwent a routine clinical examination and functional analysis of the mouth. On taking the history all subjects were asked about their awareness of various forms of parafunctional activity in their mouth. RESULTS: Almost all subjects revealed various oral parafunctions such as: bruxism, nail and pen biting, chewing gum, and biting the mucosa of lip or cheek. These habits were present singly or as double, triple or even fourfold coincidences in a single person. The most frequent oral parafunctions were habitual gum chewing and bruxism. Subjects were very seldom aware of the last parafunction. TMDs were more prevalent in the presence of bruxism than in other oral parafunctions. CONCLUSIONS: The studied students revealed various types of oral parafunctions, however most of them were not aware of clenching and grinding their teeth.

Effects of caffeine on human health.

Caffeine is probably the most frequently ingested pharmacologically active substance in the world. It is found in common beverages (coffee, tea, soft drinks), in products containing cocoa or chocolate, and in medications. Because of its wide consumption at different levels by most segments of the population, the public and the scientific community have expressed interest in the potential for caffeine to produce adverse effects on human health. The possibility that caffeine ingestion adversely affects human health was investigated based on reviews of (primarily) published human studies obtained through a comprehensive literature search. Based on the data reviewed, it is concluded that for the healthy adult population, moderate daily caffeine intake at a dose level up to 400 mg day(-1) (equivalent to 6 mg kg(-1) body weight day(-1) in a 65-kg person) is not associated with adverse effects such as general toxicity, cardiovascular effects, effects on bone status and calcium balance (with consumption of adequate calcium), changes in adult behaviour, increased incidence of cancer and effects on male fertility. The data also show that reproductive-aged women and children are 'at risk' subgroups who may require specific advice on moderating their caffeine intake. Based on available evidence, it is suggested that reproductive-aged women should consume

[Free vascularized joint transfer during surgery for hypoplastic thumb]. / Wolny unaczyniony przeszczep stawu w leczeniu operacyjnym wrodzonej hipoplazji kciuka.

Hypoplasia and aplasia of the thumb constitute approximately 11% of congenital disorders of the upper extremity. Surgical treatment depends on type of disorder in Blauth classification used in our Department. Soft tissue procedures and pollicisations are performed most often. Microsurgical transplantation of interphalangeal joint from the toe is an alternative. This paper describes a case of microsurgical treatment in 20 years old patient with hypoplastic thumb. Two months after surgery the range of motion in transplanted joint was between 20 and 75 degrees.

Teratogenic, biochemical, and histological studies with mice prenatally exposed to 2.45-GHz microwave radiation.

Pregnant CD-1 mice were exposed to 2.45-GHz continuous wave microwave radiation at an incident power density of 30 mW/cm2. The local specific absorption rate near the uterine area (deep colonic location), as determined from time-temperature profiles measured with a Vitek thermistor probe, was 40.2 mW/g. Groups of mice were exposed 8 hr per day through Days 1-6 or 6-15 of pregnancy. Other groups of animals were exposed to an elevated ambient temperature of 31 degrees C which increased the colonic temperature 2.3 degrees C, the same as that produced by the microwaves. Sham-irradiated groups of animals were treated exactly the same as the microwave-exposed animals. For the two conditions, temperature exposed and sham exposed, two groups of animals were used. One group was handled in the same manner as the microwave-irradiated group and the other group was not handled so as to evaluate the effects of stressing the animals by handling. Eleven groups of animals were used in the complete study: five groups for gestational Days 1-6, five groups for gestational Days 6-15, and one group of cage control animals. On Day 18 of gestation the dams of all experimental groups were sacrificed and their reproductive status was determined. The fetuses were examined for visceral and skeletal alterations. Brain cholinesterase activity and histology were evaluated in the groups exposed on Days 6-15. The results show that microwave radiation increases embryo lethality at the early stages of gestation (exposure Days 1-6). Fetal toxicity and teratogenicity were not significantly increased by exposure to microwaves on either Days 1-6 or 6-15 of gestation. Cholinesterase activity and histology of the brain of 18-day-old fetuses were not adversely affected.

Effects of 2.45 GHz CW microwave radiation on embryofetal development in mice.

The embryofetal toxicity and teratogenicity of plane-wave 2.45 GHz continuous wave (CW) microwave radiation at different intensities were investigated in the CD-1 mouse. Mice were exposed on days 1-15 of gestation to an incident power density of 5 mW/cm2 (specific absorption rate of 6.7 mW/gm) and either on days 1-6 or 6-15 of gestation to 21 mW/cm2 (specific absorption rate of 28.14 mW/gm) or to 30 mW/cm2 (specific absorption rate of 40.2 mW/gm) for 8 hours daily. Exposure either on days 1-6 or 6-15 of gestation to a power density of 21 or 30 mW/cm2 caused an increase in colonic temperature of exposed dams of 1 degree C and 2.3 degrees C, respectively. To distinguish between "thermal" and "nonthermal" effects of 21 or 30 mW/cm2, groups of mice were also exposed to elevated ambient temperature to raise their body temperature to the level of those animals exposed to microwave. Ambient temperatures of 30 degrees C and 31 degrees C increased the deep colonic temperature to that obtained with the 21 and 30 mW/cm2 microwave exposure, respectively. The temperature-exposed mice were handled in exactly the same manner as the microwave-exposed mice. A significant reduction in maternal weight gain, either during treatment on days 1-6 or 6-15 of gestation was observed in females of all handled groups. Handling plus exposure to elevated ambient temperature (30 degrees C or 31 degrees C) during days 6-15 of gestation increased this reduction in maternal weight gain. A significant decrease in implantation sites per litter and reduction in fetal weight was noted in the group exposed to 30 mW/cm2 during days 1-6 of gestation. Exposure of mice to a power density of 30 mW/cm2 (days 6-15 of gestation) resulted in a slight, but significant increase in the percentage of malformed fetuses, predominantly with cleft palate, when compared to all other groups.

Embryotoxicity of broadband high-frequency noise in the CD-1 mouse.

The teratogenic and embryofetotoxic potential of a broad band of high-frequency (16-42 kHz), high-intensity (110 dB sound pressure level), temporally uniform noise was evaluated in CD-1 mice. The frequency band of the noise overlapped the most sensitive region of the mouse's auditory system. The exposure period (d 6-15) included the period of major organogenesis. Decreased fetal weight, pregnancy rate, and increased late-stage fetal mortality were observed in the offspring of exposed dams, but the statistical significance of these effects was low (p less than 0.1).

Embryotoxicity of various noise stimuli in the mouse.

Different noise exposure paradigms were studied to determine their teratogenic and embryo-fetotoxic potential in the CF-1 mouse. Female mice were exposed from days 1-6 or from days 6-15 of gestation to one of three noise exposure paradigms which differed widely in level, spectral, and temporal characteristics. Paradigms for noise exposure were chosen to represent semi-continuous exposure to extremely high-intensity noise (jet engine noise at 126 dBA, from noon to midnight); to represent startling type noise composed of alarm bells, jet engine noise, or narrow band warning devices at 110 dBA, with pseudorandom onset and duration of each controlled by a microprocessor (exposure time of 18% over each 24 hour period); and finally to represent very high frequency noise (18-20 kHz tones, derived from a device commercially marketed for repelling rodents, with exposure from noon to midnight). On day 18 of gestation the females were sacrificed, their reproduction status determined, and the concepti were examined for toxicity and for external, visceral, and skeletal alterations. Maternal plasma corticosterone levels were measured at different periods of gestation. Significantly decreased pregnancy rate was noted in all groups exposed to noise except in the group exposed to the very high frequency noise from days 6-15 of gestation. Significant embryolethal effects occurred in the group exposed to the extremely high intensity jet noise paradigm, from days 1-6 of gestation, and significant fetolethal effects occurred in the group exposed to the very high frequency noise paradigm from days 6-15 of gestation. No significant noise-related changes were noted in the incidence of structural alterations or in the concentration of plasma corticosterone.

Arthrogryposis: an inherited defect in newborn calves.

Arthrogryposis, frequently associated with cleft palate, scoliosis and kyphosis, has been investigated in pure and crossbred Charolais calves. During a 3-year study, a total of 76 congenitally malformed arthrogrypotic calves from 41 purebred and commercial Charolais herds was investigated. Investigations of the management, feeds, water and poisonous pasture plants in 6 herds reporting deformed calves did not reveal any factors which could be associated with the appearance of the defect. Analysis of pedigrees and matings which produced arthrogrypotic calves revealed that the arthrogryposis syndrome in the Charolais breed and its crosses in Canada is genetic in origin and caused by an autosomal recessive gene with complete penetrance in the homozygous state.