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Children with autism spectrum disorder (ASD) have difficulties perceiving and producing skilled gestures, or praxis. The inferior parietal lobule (IPL) is crucial to praxis acquisition and expression, yet how IPL connectivity contributes to autism-associated impairments in praxis as well as social-communicative skill remains unclear. Using resting-state functional magnetic resonance imaging, we applied independent component analysis to test how IPL connectivity relates to praxis and social-communicative skills in children with and without ASD. Across all children (with/without ASD), praxis positively correlated with connectivity of left posterior-IPL with the left dorsal premotor cortex and with the bilateral posterior/medial parietal cortex. Praxis also correlated with connectivity of right central-IPL connectivity with the left intraparietal sulcus and medial parietal lobe. Further, in children with ASD, poorer praxis and social-communicative skills both correlated with weaker right central-IPL connectivity with the left cerebellum, posterior cingulate, and right dorsal premotor cortex. Our findings suggest that IPL connectivity is linked to praxis development, that contributions arise bilaterally, and that right IPL connectivity is associated with impaired praxis and social-communicative skills in autism. The findings underscore the potential impact of IPL connectivity and impaired skill acquisition on the development of a range of social-communicative and motor functions during childhood, including autism-associated impairments.

A novel method has been developed for optimally processing biopsy specimens combining freeze-substitution with low-temperature plastic embedding. Immunohistochemistry and conventional histochemical stains were all readily performed on tissue displaying high-quality morphologic preservation. Labile antigens, especially lymphoid cell surface antigens, were well preserved. This new method avoids the need for tissue fixation and combines the superior morphologic preservation of fixed embedded tissue with the reactivity of cryostat sections. This method ensures that diagnostic information from even the smallest biopsy specimen is maximized because a wide range of phenotypic markers can be applied and evaluated in relation to high-quality morphologic preservation of tissue. Biopsy specimens are stored at room temperature without loss of tissue-specific characteristics during storage.

The potential value of DNA aneuploidy, in distinguishing benign from malignant follicular thyroid neoplasms, was studied. The nuclear DNA content of 65 follicular thyroid neoplasms (52 adenomas and 13 carcinomas) was determined by flow cytometric analysis of paraffin embedded material; in 58 cases preparations were technically satisfactory. In 22 follicular neoplasms DNA analysis was also performed on fresh material obtained by fine needle aspiration of surgical specimens. Cell cycle analysis was performed on both fresh and fixed specimens. An aneuploid DNA profile was found on analysis of fixed tissue in eight of 45 (18 per cent) follicular adenomas and four of 13 (31 per cent) follicular carcinomas. DNA aneuploidy was also found in six of the 22 (27 per cent) fresh preparations from follicular adenomas. The frequency of DNA aneuploidy in apparently benign and malignant follicular neoplasms was similar. Follicular thyroid neoplasia are best regarded as a single entity with a low incidence of local and distant spread. All follicular neoplasia are therefore best excised.

The preoperative diagnosis of some thyroid neoplasms remains difficult even with the routine use of fine-needle aspiration cytology. The potential of nuclear magnetic resonance imaging (MRI) to discriminate between different thyroid pathologies was explored prospectively and compared with the final pathology in a series of 37 patients. MRI yielded high-quality images of the thyroid swelling but did not provide additional information to differentiate benign from neoplastic lesions. MRI does not contribute to the routine management of thyroid swellings.

In response to internal parasitization by Banchus flavescens Cresson, larvae of the cabbage looper and, to somewhat lesser degrees, larvae of the celery looper and the alfalfa looper, form a bubble-like cyst between the cuticle and epidermis on the dorsum of the penultimate segment. Larvae of the flax bollworm and the clover cutworm do not respond in this way; rather, they promptly and effectively encapsulate the parasites within their haemocoele. The stimulant for cyst formation in the loopers seems to be produced by the acid (= poison) accessory gland of the female wasp; this same secretion(s) serves to protect the parasite from haemocytic encapsulation.

Six patients are described to illustrate the operative management of tubulovillous neoplasms of the duodenum. Pancreaticoduodenectomy is appropriate for associated invasive carcinoma. Transduodenal submucosal excision of tubulovillous neoplasms with resection and reconstruction of the distal bile and pancreatic ducts if necessary is a satisfactory alternative when the neoplasm has not penetrated the muscularis mucosae.

In response to internal parasitization by Banchus flavescens Cresson, larvae of Trichoplusia ni (Hubner) form a bubble-like cyst between the cuticle and epidermis on the dorsum of the penultimate segment. After the parasite egg hatches, its larva migrates to and enters the cyst and is then sluffed off with the exuviae at the next moult. The nature and development of the cyst is discussed. We propose that this unique and successful defense reaction by T. ni be called cuticular encystment.

Summary.— A patient with histologically proven Crohn's disease of the ileum and caecum presented with unusual ulceration of the mouth 3 years after subtotal colectomy. Worsening of bowel symptoms was associated with exacerbation of oral ulceration on several occasions. The areas of ulceration in the mouth were in relation to a sarcoid reaction typical of Crohn's disease.

SUMMARY.— A case of generalized muscle weakness due to prolonged chloroquine ingestion is described. The clinical and histological findings are discussed. Eventual recovery of function can be expected.