Effects of a gastric implant on body weight and gastrointestinal hormones in cafeteria diet obese rats

In order to evaluate the effectiveness of a gastric implant in an animal model of dietary obesity, silicone implants (2.5 ml) were inserted into the stomachs of male rats maintained on a chow or "cafeteria" diet. At the time of implantation, the cafeteria fed rats weighed 14% more than chow fed controls. Overweight cafeteria fed animals lost weight in response to the gastric implant, whereas control chow fed animals did not. Both implant groups had significant increases in stomach weights in contrast to sham implant groups, but the increase was much less in the cafeteria diet group. The fasting plasma levels of the gastrointestinal hormones, gastrin and pancreatic polypeptide, and oxytocin (a marker of vagal afferent function) were measured by radioimmunoassay. Cafeteria fed sham or implanted animals had significantly higher fasting levels of plasma oxytocin and gastrin, and significantly lower plasma levels of pancreatic polypeptide than the chow fed groups. These studies demonstrate that the gastric implant has more effect on weight in overweight animals on a palatable mixed diet, perhaps related to both mechanical and neural factors.     

Substance P and somatostatin content and transport in the vagus and sciatic nerves of the aging Fischer 344 rat

The two widely distributed neuropeptides, substance P (SP) and somatostatin (SS), are synthesized in cell bodies of the sensory ganglia of the vagus and sciatic nerves and transported bidirectionally toward the central nervous system and sites of sensory innervation. In this study, the content of both peptides was measured in the vagus and sciatic nerves of Fischer 344 rats aged 4, 12 and 25 months. In addition, as an indicator of biosynthesis within the sensory ganglia, the quantity of neuropeptide transported during 22 hours in a peripheral orthograde direction was measured using the ligation technique in animals age 12, 18 and 25 months. The content and transported quantity of SP was unchanged or slightly increased in both nerves as a function of age. Somatostatin content was unchanged and transport increased in the vagus of older rats. In contrast, in the sciatic nerve, SS content was reduced by more than 30% in older rats (p less than 0.01); transported somatostatin was proportionately reduced (p less than 0.05). These findings demonstrate that neuropeptide levels in the sensory vagus are not reduced as a function of age. Somatostatinergic dorsal root ganglion neurons may be selectively vulnerable in the aging Fischer rat.     

Child psychiatry: one nation

This essay discusses the position of child psychiatry as a subspecialty in Canada today. Proceeding from a review of a paper written by Dr. Quentin Rae-Grant in 1970 "Adult and Child Psychiatry--One or Two Nations?" the author, using the concept of a nation as a metaphor, explores the evolution of child psychiatry as a subspecialty in Canada. The history of child psychiatry in Canada is reviewed briefly; from its early beginnings to an increased understanding of its uniqueness as a subspecialty, finally through to the formation of the Canadian Academy of Child Psychiatry in 1980. The essay stresses the mutuality of our dependence on the Canadian Psychiatric Association. The author emphasizes our mutual dependence on the greater organizational body of psychiatrists, and encourages a greater participation of child psychiatrists within the Canadian Psychiatric Association. The author also emphasizes the need to have a closer relationship with the Canadian Paediatric Society. In addition, the author discusses in some detail the more complex and controversial relationship between child psychiatry and the Royal College of Physicians and Surgeons of Canada. Finally the author emphasizes the importance of a close working relationship with the American Academy of Child and Adolescent Psychiatry. All of these relationships are emphasized in terms of mutual dependence.     

Genetic Analysis Workshop II: combined segregation, linkage, and association analysis

A combined segregation, linkage, and association analysis using the program COMBIN was performed on the simulated pedigree data prepared for the Second Genetic Analysis Workshop. The model used in COMBIN is described and the presented results illustrate its effectiveness in the analysis of such data. Linkage analysis was performed and maps for each linkage group are presented.     

Osteosarcomatosis

A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.     

Treatment of Vitamin B12 Deficiency after Gastric Surgery for Severe Obesity

Background: Vitamin B₁₂ deficiency after gastric surgery for obesity is due to a failure of separation of vitamin B₁₂ from protein foodstuffs and to a failure of absorption of crystalline vitamin B₁₂ in the presence of intrinsic factor. The purpose of this study was to determine which of four oral doses of crystalline vitamin B₁₂ was most effective in treating vitamin B₁₂ deficiency in 102 patients. Methods and Results: At time of entry into the study, the patients had a serum vitamin B₁₂ < 100 pmol L ⁻¹, were 29.9 ± 21.7 months post-op, were 37 ± 8 years old and had a body mass index of 30 ± 6 kg m⁻². Eight (8%) had had a vertical banded gastroplasty and 94 (92%) a gastric bypass. For the first 3 months all patients received 350 μg per day of crystalline vitamin B₁₂ and all increased their serum vitamin B₁₂ levels to over 100 pmol L⁻¹. The patients were then assigned to receive for a further 3 month period one of four oral doses of crystalline vitamin B₁₂-100 μg, 250 μg, 350 μg and 600 μg. Serum vitamin B₁₂ levels were greater than 150 pmol L⁻¹ after 6 months in 83.3% of patients who received 100 μg; 92.3% of patients who received 250 μg; 94.7% after 350 μg and 95.2% after 600 μg (p%0.525). Conclusion: At least 350 μg per day is the appropriate oral dose of crystalline vitamin B₁₂ after gastric surgery for obesity to correct low serum vitamin B₁₂ levels in 95% of patients.     

Brain activity and language assessment using event-related potentials: development of a clinical protocol

To test the validity of a new computerized task to assess children's receptive vocabulary, event-related potentials (ERPs) were recorded from 56 typically developing children ranging in age from 5 to 12 years. This ERP-computerized vocabulary task does not require a child to give a verbal or motor (i.e. pointing) response. Single pictures, from an existing standardized test of receptive vocabulary, were presented on a computer screen and simultaneously named either correctly (congruent) or incorrectly (incongruent) via a computer. As predicted, the N400 amplitude was found to be significantly higher to the incongruent picture-word pair (i.e. the child knew it was an incorrect pairing) than to the congruent picture-word pair (i.e. the child knew it was a correct pairing). This effect was found for each of the four age groups (5 to 6 years, 7 to 8 years, 9 to 10 years, 11 to 12 years). This task accurately estimated current receptive vocabulary in typically developing children. Although still in the development stage, it may eventually serve as an adjunct to a thorough neurological and neurodevelopmental assessment of some children presenting with moderate to severe cerebral palsy.