induce vomiting, which could then cause acute dilatation from hypokalaemia. Secondly, the hyperosmolar effect of introducing a relatively large amount of fluid and food into a stomach which has become used to less will cause dilatation.Acute dilatation of the stomach is thus a recognized, if rare, complication of any patient suffering from anorexia nervosa who is beginning treatment. It seems that conservative management alone is adequate in the acute phase provided the condition is discovered before perforation of the stomach occurs. The mortality of uncomplicated gastric dilatation is low, but after perforation it is 80% (Evans, 1968).We considered whether any medication the patients received before presentation might have caused the dilatation. One patient had been treated with diazepam and the other with chlorpromazine. We consulted Side Effects of Drugs (Meyler and Herxheimer, 1968) which made no reference to such effects after diazepam therapy. The phenothiazines have, however, on rare occasions been noted to cause a depression of gastric secretion leading to paralytic ileus in psychotic patients. This was noted in four out of 720 people studied. Since only one of our patients had received phenothiazines, however, we feel it is unlikely to have been a precipitating cause of presentation.We thank Dr. N. C. Oswald and Mr. E. G. Tuckwell for permission to report these cases which were under their care and also Mr. W. M. Castleden for his commnents and help.

In children, acquired skull defects often close spontaneously. This is most likely to take place when the dura mater and the pericranium are intact. Congenital skull defects rarely close spontaneously. Cranioplasty will be needed when a bone defect has failed to close or when it is unlikely to do so. Various methods are available: autogenous bone, acrylic resin, and metal prostheses have been widely used. A series of 68 operations performed on children under the age of 15 years is reviewed. It is concluded that shaped titanium plates are usually preferable. These can be formed by hand, or in a pressure chamber; simple defects can be closed with ready-made titanium strips. Fixation by screws is recommended. Titanium plates have been used successfully even in very young children.

SummaryTitanium strips have been used to repair skull defects when preformed metal plates are not available and simple wiring would not be enough. The technique is simple, obviates the need to dissect the dura mater, and gives greater resistance to further impact injury than an inlay technique.

As a cancer treatment modality, thermal ablation offers the advantages of being less invasive and posing fewer post-procedural complications compared to traditional cancer therapies. It involves destroying cancerous cells by subjecting them to the appropriate amount of heat dose. In the present study, high frequency ultrasound (US) ablation is theoretically examined for effectiveness as a treatment modality for intraluminal and extracorporeal cancer treatment. Objectives of this study are to 1) develop thermal-damage correlations for a variety of cancer cells and 2) design US treatment devices, based on thermal damage correlations developed, and treatment planning protocols. To achieve these goals, thermal damage information for different cell types is first determined from earlier studies or pilot experiments. Required US doses for specific tissues are determined next through numerical experiments. Device design and estimation of thermal coagulation contours is then performed by comparing temperature-history data against the thermal-damage data for a range of device parameters. Treatment protocols are finally developed based on the analysis of the results for a range of applicable device parameters. Results are presented in terms of correlations for the volume and location of ablated tissue corresponding to a range of operating parameter values.

Thermal ablation in the context of this study refers to destroying cancer cells by heating them to supraphysiological temperatures for appropriate times. Once the tumor cells and a small layer of surrounding tissue cells are killed, they are absorbed by the body over time. Compared to open surgery, radiation, and chemotherapy, thermal therapy can be less expensive and pose less risk of harmful post-procedural complications, while possessing the potential to be effective [1]. Currently microwave and radiofrequency ablation are in use for local hyperthermia; however, they lack the ability to focus heat into the target zones effectively or treat larger tumors without affecting the surrounding healthy tissue. In the current study, high frequency ultrasound (US) ablation is examined as a treatment modality because of its ability to focus and control heat effectively. Objectives of this study are to 1) develop thermal-damage correlations for US thermal therapy and 2) design delivery devices and associated treatment planning protocols. To achieve these goals, thermal damage information is first evaluated for a variety of cells and tissues from published data or pilot experiments. Required US dose levels are determined next through numerical experiments, followed by device design and estimation of thermal coagulation contours by comparing the temperature-history data against the thermal-damage data. Based on the analysis of the results for a range of parameters, namely, the applicator power, geometry, frequency, coolant parameters, treatment time, and tissue perfusion, treatment protocols are developed. Intraluminal, external, and interstitial modes of delivery are considered for focal sites in a variety of target areas. In the following sections, methods followed and sample results obtained are presented.