Biomedical subjects
Publications and source records attributed to G B Thompson.
In the United States, visceral Kaposi's sarcoma most commonly occurs in association with the acquired immune deficiency syndrome (AIDS). The authors report a unique case of primary colonic Kaposi's sarcoma in a young heterosexual HIV-negative man with chronic ulcerative colitis.
Eight-year-old British children were found to be less accurate at rejecting pseudohomophones than ordinary nonwords in a lexical decision task, but 8-year-old New Zealand children did not show this effect. A subsequent homophone decision task showed that this difference was not due to the New Zealand children being unable to distinguish pseudohomophones from other nonwords. The New Zealand children, however, were less accurate than the British children in pronouncing the pseudohomophones they had identified. It was argued that the British children tended to sound out the items before making a choice in the lexical decision task, which gave salience to phonological rather than visual information, resulting in increased errors to the pseudohomophones. It was concluded that where the British children showed this dependency on use of phonological information it was a product of the teaching approach they had experienced.
Whether tolerance develops to the "anorexia" induced by haloperidol (HAL) was determined. Rats were given HAL (2.5 or 5 mg/kg) either before or after access to milk for 53 days. Controls were given injections of saline. On Day 54, when all groups received pretest injections of the drug, only rats previously given posttest injections of HAL were tolerant. The absence of tolerance in rats previously given pretest injections suggests that tolerance is suppressed when rats are given access to food in the drugged state. It is concluded that tolerance develops to HAL as a result of pharmacological exposure but is suppressed by the "anhedonic" effect of the drug. The relevance of these findings to the role of reinforcement in behavioral tolerance is briefly discussed.
We discuss some of the issues emerging from a powerful legislative movement for preventive services over the past three years. During this time an increasing number of states passed, considered, or are currently developing breast cancer screening legislation. Most of these laws require some form of third party payment for mammography or establish breast cancer screening programs. The legislation varies markedly with regard to periodicity of examinations, ages covered, type and extent of third party coverage, dosage regulation, and radiographic equipment standards. This shows a need for common standards. Legislation provides an essential incentive for a public health response to a serious problem, but more than laws are needed. Health care providers and the general public need to be aware and take advantage of the coverage provided as a result of legislation. Moreover, public health officials need to be aware that such legislation may lead to a demand for services that exceeds present capacity to deliver them.
The administrative prevalence of mental handicap at the age of 10 years was ascertained for a group of children born 1973 and 1974. There was a birth cohort prevalence of 4.35 per 1000 live births.
In order to assess the effects of anorexigenic agents on appetitive and consummatory behavior, rats were given sweetened milk either in a bottle or by infusion through an intraoral cannula. In the first experiment, amphetamine (AMP; 0, 0.25, 0.5, and 1 mg/kg) had no effect on the intake of cannula-fed rats but suppressed the intake of bottle-fed rats at the highest two doses. Although increased activity was observed at the highest dose, bottle-fed rats drank less than cannula-fed rats at each dose of the drug. Fenfluramine (FEN; 0, 2.5, 5, and 10 mg/kg) produced a dose-dependent decrease in intake with both methods of feeding, but the effect was greater in bottle-fed rats. Although FEN had marked sedative effects at the highest two doses, bottle-fed rats drank less than cannula-fed rats at each dose of the drug. In a second experiment, cannula- and bottle-fed rats were given milk adulterated with various concentrations of quinine hydrochloride (QHCl; 0, 0.0025, 0.005, 0.01, and 0.02%). QHCl had no effect on the intake of cannula-fed rats but decreased the intake of bottle-fed rats at the highest two concentrations. In a final experiment, the effect of AMP (1 mg/kg) was assessed in a conditioned aversion paradigm. Rats were given four conditioning trials in which access to a 0.1% sodium saccharin solution was followed by an injection of AMP. Again, bottle-fed rats showed greater suppression of intake than cannula-fed rats. Taken together, these results demonstrate that anorexigenic drugs affect appetitive behavior more than consummatory behavior. The implications of these findings for understanding the mechanism of behavioral tolerance are discussed.
Eight crossbred feeder steers were used in two consecutive N balance studies to investigate the effects of infectious bovine rhinotracheitis virus (IBRV) on N kinetics. Balance Study 1, which followed a 10-d acclimation phase, consisted of 7 d of sample collection referred to as the healthy phase (d -7 to d -1). Study 2, the IBRV-infected phase, began 2 d after a nasal IBRV challenge and continued for 6 d (d 2 to d 8). A stable isotope, [15N]-glycine, was used to determine N kinetics in both studies. Steers weighed 203 kg at the beginning of the study, 208 kg at IBRV infection and 194 kg at the end of study. Infection with IBRV increased (P less than .05) urinary N excretion from 17.9 to 31.5 g/d. Daily N balance was reduced (P less than .05) during infection from 21.2 to -3.3 g/d. Total serum proteins increased (P less than .05) during infection from 6.6 to 7.1 g/100 ml, the increase being predominantly in the alpha and gamma globulin fractions. Blood urea-N increased (P less than .05) during infection from 6.5 to 12.9 mg/100 ml. The urine excretion curve of the stable isotope and the N balance data indicated that IBRV infection increased N turnover and altered tissue utilization of N.
Unlike its lethal exocrine counterpart, islet cell carcinoma of the pancreas is an indolent neuroendocrine neoplasm. The majority of these tumors are hormonally active. When functioning, a number of clinical syndromes (for example, hyperinsulinism, Zollinger-Ellison and Cushing's syndromes) may be evident. Fifty-eight patients surgically treated between 1965 and 1984 were retrospectively analyzed. The purpose of this study was to determine the distribution of functioning versus nonfunctioning tumors and the response to type of therapy. Mean postoperative follow-up was 7.4 years. Survival and prognostic indices were calculated by the Kaplan-Meier method and compared with log-rank tests. Of the group, 54% had functioning and 46% nonfunctioning tumors. Gastrinomas were the most common functioning tumors encountered (19%). Of interest was the finding that nonfunctioning tumors increased steadily during the last 15 years of the study (25% to 65%). Curative resections were performed in 15 (26%) and noncurative procedures in 43 patients (74%), with an overall operative mortality rate of 3%. Symptomatic improvement was achieved in 90% (curative) and 51% (noncurative). Survival at 3 years was 87% and 66% for the curative and noncurative groups, respectively (p less than 0.1), with an overall 5-year survival of 42%. The absence of hepatic metastases was a major predictor of survival at 3 years (82% vs 56%, p less than 0.05). Survival was statistically better at 3 years in those patients with gastrinomas compared with patients with nonfunctioning tumors (91% vs 58%, p less than 0.05). Although surgical cure is rare, significant long-term palliation may be achieved in a large percentage of patients with an aggressive surgical approach, occasional total gastrectomy, combination chemotherapy, H2 blockade, when indicated, and, most recently, with the new long-acting analogue of somatostatin.
In this article, the effect of chronic injections of amphetamine on feeding and behavioral activation was analyzed. Rats were given milk either through an intraoral cannula or in a standard drinking tube, and the level of their behavioral activation was monitored before, during, and after access to the milk. Cannula- and bottle-fed rats given saline showed similar patterns of intake and activity. Bottle-fed rats given amphetamine (2 mg/kg) showed substantially greater suppression of intake than did cannula-fed rats, but recovered more rapidly, confirming earlier findings (Salisbury & Wolgin, 1985). Such recovery was accompanied by a suppression of stereotyped head scanning movements during access to milk, but not before and after milk access. In contrast, cannula-fed rats given amphetamine showed stereotyped head scans throughout the session for the duration of the experiment. These results suggest that tolerance to the suppression of intake by amphetamine involves learning to suppress stereotyped head movements. The constraints on such learning are briefly discussed.
A 33 year old woman with chronic myelogenous leukemia presented with clinical symptoms and hemodynamic signs suggestive of pulmonary embolism. Initial angiographic studies supported the diagnosis of a massive saddle pulmonary embolus, and an inferior vena cava filter was inserted. However, subsequent autopsy revealed unsuspected angioinvasive pulmonary aspergillosis with secondary in situ thrombosis. The clinical features and diagnostic considerations in immunocompromised patients presenting with the clinical picture of pulmonary embolism are discussed.
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The authors report a case of symptomatic arachnoid diverticulum, which was located anterior to the spinal cord and covered the entire length of the spinal canal. The patient underwent cervical laminectomy and cystoperitoneal shunting with subsequent neurological improvement. The causes, clinical manifestations, diagnosis, and management of spinal arachnoid diverticulum are discussed.
One hundred fifty-four patients with gastrointestinal carcinoid tumors were surgically treated at our institution between 1972 and 1982. The most frequent primary sites were the ileum (43%), rectum (30%), appendix (11%), jejunum (6%), stomach (6%), and duodenum (1%). Asymptomatic tumors were discovered incidentally in 93 patients (60%). Symptomatic tumors were common (48%) among the group with ileal carcinoid tumors. Except for endoscopy, preoperative studies were of limited value. The malignant carcinoid syndrome was present in 12 patients (nine with ileal tumors). One hundred forty-seven patients underwent surgical or endoscopic resection of the primary tumor; the overall operative mortality rate was 2.6%. Of significance was the high incidence (18%) of metastasis from ileal primary tumors smaller than 1 cm.
We reviewed the case histories of 350 patients who were diagnosed as having intracranial meningeal tumor between 1960 and 1981. Of these, four patients (1.1%) had meningiomas during childhood. The patients were two boys and two girls, and postoperative observation ranged from 6.5 to 38.5 years. All four patients presented with seizures. In three out of four patients, the tumors were located in the convexity regions; the other was intraventricular. One of the four tumors demonstrated histologic malignancy, and the patient subsequently died; radiation therapy may have prolonged the survival of this particular child, however. The other three children with benign meningeal tumors have all enjoyed good-quality, long-term survival since the excisions of their tumors and the tumors' dural attachments.
The authors report two patients who suffered ischemic necrosis of their scalps after preoperative therapeutic embolic occlusion of the external carotid artery and its terminal branches for highly vascular meningeal tumors. Local anesthesia, selective catheterization of the external carotid artery, and radiopaque polyvinyl alcohol and Gelfoam as embolic agents were used. The various complications of external carotid artery embolization are reviewed. The importance of preserving normal branches of the external carotid artery (especially the superficial temporal artery) during embolization and of careful design of the scalp flap to avoid ischemic necrosis is emphasized.
The authors report 257 patients who underwent 338 craniotomies for the removal of meningiomas. The average duration of observed survival was 9.0 years, while that with acceptable quality of life was 8.3 years. Multiple factors including the size and location of tumors, the degree of tumor excision, the histological features, and the preoperative condition of the patients are important in both duration of survival and quality of life following surgery for intracranial meningiomas. Computerized tomography permits early diagnosis and is invaluable in follow-up assessment. It allows for recognition of small recurrent tumors, and offers a better opportunity for complete removal and, subsequently, a longer duration of reasonable survival. Radiation therapy may prolong survival time in patients with malignant meningiomas, but it fails to delay further tumor recurrences following its delivery to patients with recurrent tumors. There are multiple predisposing factors responsible for the development of postoperative seizures. These include tumor recurrence involving highly functional anatomical areas of the brain, history of preoperative seizures, and intraoperative factors such as excessive brain retraction and the sacrifice of major draining or bridging veins. Intraoperative complications may be decreased by using osmotic diuretics and subarachnoid drains, meticulous dissection, and with the increased awareness and preservation of the important venous structures.
Subarachnoid hemorrhage (SAH) was induced in 50 rabbits by injecting 1.25 cc/kg of autologous, well heparinized, fresh arterial blood into the cisterna magna, followed by suspending the animals in a head-down position at 30 degrees for 15 minutes. The animals were evenly divided into five groups: a control group, or groups receiving post-SAH prostacyclin (PGI2), carbacyclin, thromboxane A2 (TXA2) synthetase inhibitor (OKY-1581), or nutralipid. Radiographic vertebrobasilar arterial spasm was demonstrated on the 3rd day post-SAH in the control animals. This was decreased in the prostacyclin and the carbacyclin groups and was absent in the OKY-1581 and the nutralipid groups. Cerebral blood flow (CBF) measurements on the 4th day post-SAH using the xenon-133 technique failed to reveal any significant difference between the prostacyclin, the carbacyclin, and the control groups, but flows in the nutralipid and the OKY-1581 groups were significantly higher. There was a good correlation between the clinical status and the CBF. Intracytoplasmic vacuolation and detachment of the vascular endothelium, seen ultrastructurally, may account for the impaired synthesis of prostacyclin. Exogenous prostacyclin and carbacyclin decreased vasospasm but failed to improve cerebral perfusion. OKY-1581 blocked the synthesis of the potent vasoconstrictor, TXA2, which is not only formed during platelet aggregation but also induces platelet aggregation. Nutralipid contains linolenic acid, a precursor of eicosapentaenoic acid (EPA), which is more potent in inhibiting platelet aggregation and in blocking TXA2 production. The various fatty acid constituents of nutralipid bind to albumin and thereby shorten the half-life of TXA2.
Colloid cysts may be found in any part of the third ventricle. The authors report that four out of 12 patients with colloid cysts of the third ventricle suffered acute neurological deterioration, and unilateral ventriculostomy resulted in dramatic recovery in two patients. Unilateral ventriculostomy followed by clinical assessment and computed tomographic scanning is an acceptable approach in emergency situations; computed tomographic scanning allows early detection of third ventricular colloid cysts. Ventriculoperitoneal shunting provides a laternative measure to surgical removal of the cyst. Definitive management soon after diagnosis and before acute neurological deterioration is recommended. The cases presenting with sudden death in the literature are reviewed.