Acute hyperthermia following stereotactic radiosurgery for pituitary adenoma

A 71-year-old male presented with a large pituitary adenoma with superior extension into the optic chiasm and suprasellar cistern. He was treated with stereotactic radiosurgery to a dose of 16 Gy. Approximately 1 h after radiosurgery he developed fever; his temperature peaked at 105.1 degrees F and normalized about 20 h later. This case demonstrates that acute hyperthermia is a potential complication following high dose stereotactic radiosurgery for large pituitary tumours.     

Tuberculosis versus lymphomas in the abdominal lymph nodes: evaluation with contrast-enhanced CT

OBJECTIVE: Tuberculosis in the abdominal lymph nodes may be difficult to distinguish from lymphomas. This study evaluated specific CT imaging criteria for differentiating these entities. MATERIALS AND METHODS: We retrospectively reviewed the anatomic distribution and CT enhancement patterns of disease in 69 patients, 26 (38%) with tuberculosis and 43 (62%) with untreated lymphomas involving abdominal lymph nodes. Of the patients with tuberculosis, five (19%) had disseminated disease and 21 (81%) had nondisseminated disease. Of the patients with lymphomas, 16 (37%) had Hodgkin's disease and 27 (63%) had non-Hodgkin's lymphoma. RESULTS: Disseminated and nondisseminated tuberculosis involved predominantly lesser omental, mesenteric, anterior pararenal, and upper paraaortic lymph nodes. Lower paraaortic lymph nodes were involved more often in Hodgkin's disease (15 patients [94%]), non-Hodgkin's lymphoma (24 patients [89%]), and disseminated tuberculosis (five patients [100%]) than in nondisseminated tuberculosis (one patient [5%]). Mesenteric lymph nodes were involved more often in disseminated tuberculosis (four patients [80%]) and nondisseminated tuberculosis (11 patients [52%]) than in Hodgkin's disease (one patient [6%]) (p < .01). Anatomic distribution was not different between disseminated tuberculosis and non-Hodgkin's lymphoma. Tuberculous lymphadenopathy commonly showed peripheral enhancement, frequently with a multilocular appearance, whereas lymphomatous adenopathy characteristically showed homogeneous attenuation (14 patients [87.5%] with Hodgkin's disease and 19 patients [70%] with non-Hodgkin's lymphoma [p < .01]). CONCLUSION: Our findings indicate that the anatomic distribution and specific enhancement patterns of lymphadenopathy seen on contrast-enhanced CT can be useful in differentiating between tuberculosis and untreated lymphomas of the abdominal lymph nodes.     

Brain metabolic changes in major depressive disorder from pre- to post-treatment with paroxetine

Functional brain imaging studies of subjects with Major Depressive Disorder (MDD) have suggested that decreased dorsolateral (DLPFC) and increased ventrolateral (VLPFC) prefrontal cortical activity mediate the depressed state. Pre- to post-treatment studies indicate that these abnormalities normalize with successful treatment. We performed [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) scans on 16 outpatients with MDD before and after treatment with paroxetine (target dose = 40 mg/day). Regions of interest (ROIs) for this analysis were drawn by a rater blind to subject identity on the magnetic resonance image of each subject and transferred onto their coregistered PET scans. We hypothesized that DLPFC metabolism would increase, while ventral frontal metabolism [in the VLPFC, the orbitofrontal cortex (OFC), and the inferior frontal gyrus (IFG)] would decrease with successful treatment. Treatment response was defined as a decrease in the Hamilton Depression Rating Scale of > 50% and a Clinical Global Improvement Scale rating of 'much' or 'very much' improved. By these criteria, nine of the subjects were classified as treatment responders. These responders had significantly greater decreases in normalized VLPFC and OFC metabolism than did non-responders. There were no significant effects of treatment response on change in the DLPFC or IFG in this sample. However, there was a positive correlation between change in HAM-D scores and change in normalized IFG and VLPFC metabolism. There were no significant interactions with laterality. On pre-treatment scans, lower metabolism in the left ventral anterior cingulate gyrus was associated with better treatment response. These findings implicate ventral prefrontal-subcortical brain circuitry in the mediation of response to serotonin reuptake inhibitors in MDD.     

Intravitreal gas injection diminishes hyaluronic acid

OBJECTIVES: To determine if compression of the vitreous by an intraocular gas bubble diminishes the concentration of hyaluronic acid (NaHA). MATERIALS AND METHODS: Eighteen albino rabbits had air, xenon or perfluoroethane (C2F6) injected into the vitreous to displace 12.5% to 90% of the vitreous volume. After the gas was absorbed, the vitreous was analyzed for NaHA by the Carbazole method (1, 13). RESULTS: A 90% displacement diminished the NaHA concentration by 18.6%. Lesser displacements caused a lesser loss, but the differences are not significant. CONCLUSION: Intraocular gas injections, both large and small, reduce the concentration of NaHA and destabilize the vitreous structure.     

Inhibition and substrate activity of conformationally rigid vigabatrin analogues with gamma-aminobutyric acid aminotransferase

Several cyclopentene GABA analogues were synthesized as conformationally rigid analogues of the epilepsy drug vigabatrin and tested as inhibitors and substrates of gamma-aminobutyric acid aminotransferase (GABA-AT). None of these compounds produced time-dependent inhibition. (1R, 4S)-(+)-4-Amino-2-cyclopentene-1-carboxylic acid ((+)-3), (4R)-(-)-4-amino-1-cyclopentene-1-carboxylic acid ((-)-4), and d, l-3-amino-1-cyclopentene-1-carboxylic acid (6) are good substrates. The K(m) and k(cat) values for the latter two compounds are very similar to those of GABA, suggesting that they bind in an orientation similar to that of GABA. The K(m) value for (+)-3 is 24 times lower than that for GABA, although its k(cat) value is only one-fourth that for GABA; nonetheless, it is a better substrate for GABA-AT than is GABA. All of these compounds, as well as the enantiomers of 3 and 4 and d, l-trans-4-amino-2-cyclopentene-1-carboxylic acid (5), are competitive inhibitors of GABA-AT. These results demonstrate the effects of the carboxylate group orientation and the stereochemistry of the amino and carboxylate groups on the substrate activity and inhibitor activity, and this should be important to the future design of inhibitors of GABA-AT.     

Cancer in the elderly patient. Unique aspects of presentation, management and screening.

The high incidence of cancer in the rapidly expanding geriatric population presents a major challenge to the health care field. Since most cancers present and behave similarly in both older and younger persons, similar approaches to management must be considered in both. The elderly, however, are a heterogeneous group with individuals demonstrating varying degrees of comorbidity and physiologic change. Decisions, therefore, should be based on a sound knowledge of geriatric assessment and the factors important for "successful" aging rather than on chronological age alone.     

Effect of retinoids on the induction of colon cancer in F344 rats by N-methyl-N-nitrosourea or by 1,2-dimethyihydrazine

The possible modifying effect of synthetic and natural retinoidson the incidence of colon cancer in rats induced by 2 intrarectaldoses of 2.5 mg of N-methyl-N-nitrosourea (MNU) given once aweek for 2 successive weeks or a single 150 mg/kg body weightdose of 1,2-dime-thylhydrazine (DMH), s.c. was investigated.Emphasis was on the effect of the development of early tumorsas visualized by endoscopy. With the retinoids N-ethyl-retinamide,N-2-hydroxyethylretinamide, N-(4-hydro- xyphenyl)-all-trans-retinamide(RAHA), and retinyl acetate (RA) administered orally after thecarcinogens, significant differences in early developing tumorswere not found. At histopathological examination of the tumorsthe RAHA + DMH group had significantly fewer adenomas per animal.The percentage of adenoma bearing rats was significantly lowerin groups receiving RAHA + DMH or RA + DMH. However, food consumptionwas lower in rats consuming either RAHA or RA. Retinyl palmitate(RP) and RAHA was administered intrarectally to MNU-inducedrats either before or after the carcinogen. When administeredbefore MNU, RP caused a significant increase in the percentageof tumor bearing animals and the average number of tumors peranimal as visualized endos copically. At histopathological examination,all retinoid groups except RAHA given after the carcinogen,produced significantly more adenomas per animal and a significantlygreater adenoma incidence than did the control groups. Thus,in two systems, the oral administration of retinoids did notclearly inhibit the early or later stages of colon tumor development.Inirarectal infusion of two retinoids had no effect on colonicmor phology but at histopathological examination of later stagetumors there was an enhanced adenoma response.     

Risk factors and costs associated with an asthma attack

BACKGROUND: A study was undertaken to identify asthma patients at risk of an attack and to assess the economic impact of treatment strategies. METHODS: A retrospective cohort analysis of a representative data set of 12 203 patients with asthma in the UK over a one year period was performed. Logistic multiple regression was used to model the probability of an attack occurring using a set of categorised predictor factors. Health service costs were calculated by applying published average unit costs to the patient resource data. The main outcome measures were attack incidence, health service resource use, drug treatment, and cost estimates for most aspects of asthma related health care. RESULTS: Children under five years of age accounted for 597 patients (5%), 3362 (28%) were aged 5-15 years, 4315 (35%) 16-44, 3446 (28%) 45-74, and 483 (4%) were aged over 74 years. A total of 9016 patients (74%) were on some form of prophylactic asthma medication; 2653 (22%) experienced an attack in the year data collection occurred. Overall health care expenditure was estimated at pound2.04 million. The average cost per patient who had an attack was pound381 compared with pound108 for those who did not, an increase of more than 3.5 times. In those aged under five and those over 75 years of age there were no significant markers to identify risk, but both groups were small in size. The level of treatment step in the British Thoracic Society (BTS) asthma guidelines was a statistically significant factor for all other age groups. Night time symptoms were significant in the 5-15, 16-44 and 45-74 age groups, exercise induced symptoms were only significant for the 5-15 age group, and poor inhaler technique in the 16-44 age group. CONCLUSIONS: Patients at any treatment step of the BTS asthma guidelines are at risk of an asthma attack, the risk increasing as the treatment step increases. Poorly controlled asthma may have a considerable impact on health care costs. Appropriate targeting of preventive measures could therefore reduce overall health care costs and the growing pressures on hospital services associated with asthma management.     

Outcomes of a randomized trial of hyperfractionated cranial radiation therapy for treatment of high-risk acute lymphoblastic leukemia: therapeutic efficacy and neurotoxicity.

PURPOSE: We evaluated 8-year survival and late neuropsychologic toxicity in children with acute lymphoblastic leukemia treated in a randomized clinical trial to test whether hyperfractionated (twice daily) cranial radiation therapy (CRT) can reduce incidence and severity of late toxicities associated with 18 Gy of CRT. PATIENTS AND METHODS: Between 1987 and 1995, 369 children treated on two consecutive Dana-Farber Cancer Institute Consortium protocols for high-risk acute lymphoblastic leukemia were randomly assigned to conventionally fractionated CRT (CFX) or hyperfractionated CRT (HFX) to a total dose of 18 Gy. Neuropsychologic testing was completed for 125 of 287 children in continuous complete remission. Event-free and overall survival, as well as neuropsychologic function, were compared for the two arms of the protocol. RESULTS: Eight-year event-free survival (+/- SE) was 80% +/- 3% for children randomly assigned to CFX and 72% +/- 3% for HFX (P =.06). Overall survival was 85% +/- 3% for CFX and 78% +/- 3% for HFX (P =.06). CNS relapses occurred in 2.8% of patients receiving CFX and 2.7% receiving HFX (P =.99). Cognitive function for both groups was solidly in the average range, with no group differences in intelligence, academic achievement, visuospatial reasoning, or verbal learning. Children on the HFX arm exhibited a modest advantage for visual memory (P <.05). CONCLUSION: HFX provides no benefit in terms of cognitive late effects and may compromise antileukemic efficacy. HFX should not be substituted for conventionally dosed CRT in children who require radiation therapy for treatment of acute lymphoblastic leukemia.