Characterization of choline compounds with in vitro 1H magnetic resonance spectroscopy for the discrimination of primary brain tumors

RATIONALE AND OBJECTIVES

The authors sought to compare 1H magnetic resonance spectroscopy (MRS) spectra from extracts of low-grade and high-grade gliomas, especially with respect to the signals of choline-containing compounds.

METHODS

Perchloric acid extracts of six high-grade and six low-grade gliomas were analyzed by 1H MRS at 9.4 Tesla.

RESULTS

The signals of glycerophosphocholine (GPC) at 3.23 ppm, phosphocholine (PC) at 3.22 ppm, and choline (Cho) at 3.21 ppm were identified in both types of tumors. The absolute concentrations of all Cho-containing compounds (GPC + PC + Cho) in high-grade and low-grade gliomas were significantly different. The relative contributions of each of the Cho-containing compounds to the total choline signal were also statistically different. For high-grade gliomas, the choline signal is composed of GPC, PC, and Cho in a well-balanced contribution, whereas in low-grade gliomas, the signal is largely due to GPC with a small involvement of PC and Cho.

CONCLUSIONS

The differences in the concentration and the repartition of Cho-containing compounds seem to be a marker of high-grade gliomas. They could also help to discriminate between high- and low-grade gliomas in some difficult cases, especially if there is histologic uncertainty between anaplastic astrocytomas and low-grade oligodendrogliomas.

Placebo-controlled double-blind food challenge in asthma

To determine the prevalence of food allergy as a cause of exacerbation of asthma, we studied 300 consecutive patients with asthma (7 months to 80 years of age) who attended a respiratory clinic. Each patient was screened for possible food allergy by means of a questionnaire and by skin prick tests with the six food allergens most common in our area. Patients with either a suggestive history and/or a positive prick test and/or RAST underwent double-blind food challenge with lyophilized food in capsules or food mixed in a broth to disguise its taste. Pulmonary function tests and symptoms were followed for 8 hours after each challenge. Of the 300 patients screened, only 25 had either a history or skin prick tests or RAST responses suggestive of food allergy. Twenty patients had interpretable food challenges. In these 20 patients, food challenge caused asthma in six and caused other symptoms (atopic dermatitis and gastrointestinal symptoms) in five. On rechallenge after pretreatment with disodium cromoglycate (300 mg 30 minutes before the food challenge), the asthmatic response was blocked in four of five subjects. The patients with asthma with food allergy were generally young, had a current or past history of atopic dermatitis, and high total serum IgE levels. Our findings confirm that food allergy can elicit asthma, but its incidence is low, even in the population attending a specialty clinic. Food elimination diets should not be prescribed for all patients reporting an adverse reaction to foods or having a positive skin prick test and/or RAST with food allergens. In patients with asthma caused by food allergy, disodium cromoglycate may be used to complement elimination diets.

[Evaluation of the medical and therapeutic theorical cost of bronchial asthma during the first year of its treatment (author's transl)]

The medical and therapeutic cost of type II allergic asthma, was determined during the first year of its diagnosis and its treatment. The cost ranges from 4 000 up to 10 000 French francs. In every case, the basic treatment represents about three quarters of the total cost; whereas the initial assessment doesn't exceed one fifth. The most changing modules according to the patient and the physician (symptomatic contribution treatment, antibiotherapy, corticotherapy), are as well and by far the cheapest.

[Experimental basis of acupuncture analgesia]

The research realised at INSERM, Unité 103, on the acupuncture analgesia in animal has brought to light certain phenomenon concerning physical, histological and physiological facts. The acupuncture point is a point having the least electrical resistance in relation to the surrounding teguments. The analgesia points studied has an even lower resistance than the other points of the same dermatoma. This is not bound to the phenomenon of surface, as it is also found in cadaver after having cleared the skin with alcohol, ether or acetone. The microscopic analysis of certain points in man and in animal has shown specific elements of the acupuncture point, under the form of a thickness of the epiderm, a modification of the collagen fibers of the derma, of the vascular spiral vessels surrounded by a network of a amyelinic fibers of the cholinergic type, with interlaced myelinic fibers. The acupuncture analgesia of the hind limb can be reproduced experimentally in rabbit, in a proportion of 72 percent in 58 rabbits. The algometric method chosen was the pin prick of the skin. This territorial analgesia can be transmitted by the serum on another rabbit.