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While impairments in reward learning have been observed in depression, individual differences also exist among healthy normative populations and these differences have been parametrically mapped onto naturally occurring inter-individual variability in neuroanatomy. To date, alterations of cortical thickness as a function of reward learning have not been studied. Structural MRI and behaviourally assessedrobabilistic reward learning data from 103 participants (nmale = 35, nfemale = 68, age = 19.0 ± 1.0 years) from the Duke Neurogenetics Study were used in our analysis. The relationship between reward learning and vertex-wise cortical thickness was tested with a multiple linear regression including gender, age, and reward task stimulus discriminability as nuisance variables. Reward learning was significantly, positively associated with cortical thickness in the right medial superior frontal cortex (t = 4.469, pFWER = .048). This is the first study exploring the relationship between cortical thickness and probabilistic reward learning. It implicates a novel region in reward learning and can thereby inform future mechanistic studies.

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A Burmese family with congenital hypertrichosis lanuginosa had an eventful history in the nineteenth century. The earlier members of this family were employed at the court of Ava, but the later ones spent their lives in show business, being widely exhibited for money in the 1880s. Their extraordinary hairiness attracted much curiosity, and they were photographed several times. The hairy Burmese are the only example of a four-generation pedigree of congenital hypertrichosis lanuginosa, which is consistent with an autosomal dominant mode of inheritance. There is good evidence that, when the members of this family were hairy, their dentition was also deficient.

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Julia Pastrana (1834-1860) has gained immortality as one of the most extreme cases of generalized hypertrichosis upon record. When she was exhibited for money in the United States and Europe during the years 1855-1860, people thronged to see her, and she was several times described in the medical press of the day. After Julia Pastrana's death in childbirth, her corpse was embalmed in a very life-like manner, and exhibited all over Europe for several decades. Later, the mummy was believed to be lost, but in 1990 it was discovered at the Oslo Forensic Institute. Some writers have included Julia Pastrana among the cases of congenital hypertrichosis languinosa. However, a microscopic examination of hair samples from the mummy shows that her hairy growth is unmistakably terminal in character, and we propose that she instead was an example of congenital, generalized hypertrichosis terminalis with associated gingival hyperplasia. While many earlier writers have asserted that Julia Pastrana's dentition was abnormal, a radiographic examination of the mummy has shown that she had a complete permanent dentition.

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The results of an 18-month prospective clinical trial of external fixation in the management of open tibial fractures at Groote Schuur Hospital, Cape Town, are reported. Liaison with the Department of Mechanical Engineering at the University of Cape Town has resulted in the development of significant improvements on the methods previously described. The value of external fixation in the management of tibial fractures is confirmed; problems encountered with this particular method are described.

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The effect of incubation temperature on the behavior of neonatal rat palatal mucosa maintained in a chemically defined medium in organ culture for periods up to 7 days was investigated. Explant survival was optimal at 37 degrees C with increasing mortality at temperatures of 34 degrees C and 30 degrees C. There was a transient increase in the epithelial mitotic activity at all temperatures, but at all time intervals mitotic activity was greatest at 37 degrees C. While the mitotic activity at 37 degrees C after 5 hr in vitro was comparable with previously described in vivo values, it was subsequently increased, only returning to values approximating those at the start of the experiment at 6 days. At 30 degrees and 34 degrees C the epithelial mitotic activity increased more slowly than at 37 degrees C; then it followed a similar pattern with time and after 5 days in vitro had fallen to values approximating initial values. At the cut edges of the explants, the rate of epithelial migration and subsequent keratinization increased with increasing temperature. It is suggested that survival of neonatal rat palatal mucosa is optimal in this organ culture system when maintained at 37 degrees C.

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A safe, effective method of large-bowel preparation is outlined, the emphasis being on a standardized technique for the average patient. The rationale for the use of the technique is briefly described, and there is a further section on the preparation of the bowel in a patient with a colostomy. The importance of a residue-free fluid diet and adequate saline purgation is stressed.

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An argon ion laser beam was tested experimentally with regard to its histological effect on and penetration of the gastric mucosa of the rat and man and its ability to induce haemostasis in traumatically produced gastric lesions and transected small blood vessels. Localized laser photocoagulation for periods of up to 5 minutes at 1 watt produced a coagulative necrosis of the gastric mucosa and half of the muscularis propria, but transmural necrosis required prolonged exposure. Laser phototherapy markedly reduced the bleeding time in experimental ulcers and small blood vessels, provided the superficial blood could be adequately dispersed from the direct beam of the laser.

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Palatal mucosa from neonatal rats was maintained under organ culture conditions in a chemically defined medium for periods up to 28 days. The histological state of the cultured palatal mucosa was compared with that of control tissue from growing animals of comparable age. The control tissues showed an increase in epithelial thickness, first noticeable at 17 days. Whilst the general structure of the tissues in organ culture was preserved for the duration of the experiment, some changes in epithelial behavior were evident. There was an increase in epithelial thickness up to 6 days, followed by a reduction in the nucleated cell layer of the epithelium to a thickness comparable with that at the start of the experiment. There was a loss of epithelial glycogen within the first day, with occasional reappearance of patchy and irregular deposits. Whereas the control of epithelial thickness appeared to be restored after 10 days in vitro, disturbances in the maturation of the keratinocytes, manifested as epithelial pearls and dyskeratotic cells, were evident at subsequent stages. Epiboly never occurred. The connective tissue component showed continued development, indicated by an increase in the thickness of collagen fibres. The overall palatal growth seen in vivo did not occur in organ culture. We suggest that the improved maintenance reported is partly the result of explanting tissues in such a way as to minimize trauma, and partly the result of incorporating serum albumin into the chemically defined medium.

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