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The assessment of the possible efficacy of regional intravenous blocks or sympathetic blocks, in general, raises a number of questions that may be answered after studying the techniques of regional pharmacologic segmental blocks and their effects on the sympathetic system. The authors present an original clinical study evaluating the capacity of regional intravenous guanethidine to induce a sympathetic blockade compared with other techniques.

Since nine years multicentre, transversal and longitudinal clinical studies on hand-arm, vibration-exposed patients are being performed in cooperation with French occupational medicine centers and social security institutions. These studies are based upon current clinical assessment and standardized, temperature-measuring cooling tests. Data acquisition uses a portable, 10-channel, micro-processor-based temperature recorder and miniature thermal sensors. Temperature is monitored at the ten finger tips continuously, before, during and after a cold stress performed in strictly controlled conditions. Data from examinations performed at outlying sites are transferred through the telephonic network to a central processing unit. Data analysis uses a specific, expert-type software procedure based upon previous clinical studies on (i) 238 "normal" subjects, and (ii) 3,046 patients with vascular disturbances of the upper extremities of various etiologies. This procedure includes a staging process which assigns each finger a class representing the degree of severity of the abnormalities of response to cold ("dysthermia") related to vascular disorders. All data processing is fully automatic and results in a printed examination report. To date, over 1,623 vibration-exposed forestry, building and mechanical workers were examined. Sixty-three per cent of patients had received high dose of vibration (daily use of chain saws, air hammers, ballast tampers over many years). Typical white finger attacks or only neurological symptoms were found in 36% and 23% of patients respectively. The rate of sever dysthermia was much higher in patients with white finger attacks (83%) than in patients without (32%). In 90% of the vibration-exposed patients, the severity of dysthermia has differed greatly from one finger to another and between hands, while in non-exposed patients with primary Raynaud syndrome the dysthermia are generally similar for all fingers but the thumbs. Of 208 forestry workers who were asymptomatic but had dysthermia on a first examination, 31% have developed vascular or neural symptoms within subsequent follow-up. Of 223 symptomatic patients with more or less severe dysthermia at a first examination performed in winter, 17% had the same abnormalities in summer and microvascular lesions at capillaroscopy, while the other 83% had reversible dysthermia and only functional capillaroscopic abnormalities. These studies suggest that temperature-measuring cooling tests performed under well-defined, standard conditions provide significant data for grading the severity and assessing the reversibility of Raynaud phenomena, and for detecting subclinical vasomotor disorders in asymptomatic patients.

The authors studied two aspects of the carpal tunnel syndrome. As far as the diagnosis is concerned, clinical signs and provocative manoeuvres compared to the accepted standard of electrophysiological studies proved to be insufficient to settle a surgical indication in 85 carpal tunnel syndromes. When surgery is needed, post-operative course is frequently bothered by pillar pain and decreased strength postponing return to manual activities. The authors performed a prospective randomized study of 3 techniques in 251 carpal tunnel releases: classical technique, Agee endoscopic technique and anterior ligamentoplasty. Strength was only improved by the last technique. The only advantage for the endoscopic technique was greater post-operative comfort.

A new approach to the assessment of breast health was developed based upon continuous ambulatory recording of breast temperature for 24 hrs. A new data acquisition system consisting of a portable, multi-channel, microprocessor-based recorder worn on a belt was developed to record temperatures. Dramatic thermal fluctuations were noted during the recordings in response to multiple stimuli (physiological, behavioral, environmental). Specific algorithms and software programs were developed to process the thermobiologic and chronobiologic information. Data processing was fully automatic and included an examination report indicating a score and a chronothermodynamic class for each of the five areas examined on each breast. The preliminary clinical studies have concerned more than 450 patients with healthy or diseased breasts.

The use of microwave hyperthermia for cancer treatment is dealt with, first analyzing the present state of the art, second from a prospective viewpoint. Follow current topics are considered: a) biological data from experiments in vitro and of animals; b) fundamental therapeutic modalities: total body hyperthermia, local hyperthermia; c) technological problems: irradiation frequency, applicators, dosimetry (non-interfering probes, microwave radiometers); d) results of preliminary clinical investigations. Prospects refer to following topics: a) technological: improvement or design of systems for producing and controlling hyperthermia; b) fundamental: models, phantoms and postoperative specimens; dielectric and thermal properties on tissues; part of the vascularization; c) clinical: treatment procedures, long-term therapeutic trials (exclusive or combined hyperthermia, cancerous and healthy tissues).

This attempt at comparison between the absorption and thermogenesis of breast tumour tissue is currently being continued using a larger group of patients and complemented by measurement of tumour thermogenesis in situ and of the acoustic properties of operative specimens. Such studies define the contributions of thermographic and ultrasonic findings in diagnosis, prognosis and indications for biopsy and treatment, by their integration and combination alongside the data obtained by palpation/inspection and radiological, cytological and histological findings.

Unlabelled: Reference was made to a series of 35 cases of malignant melanoma which had not been operated on, and contributions of thermography in the following were taken into consideration. 1., Diagnosis: the complementary nature of clinical, thermographic and histological information, both for the tumour and the lymph nodes; differentiation between less thermogenic malignant melanomas (Dubreuilh melanosis, LMM and SSM) and the forms giving rise to extensive and intense hyperthermy (NM). 2., Prognosis: proposal of a prognostical classification which permits the evaluation of malignancy and, to a certain degree, the prediction of survival in a manner which is more significant than the histo-topographical classification. 3., Follow-Up: detection of local recurrences and/or lymph-node metastases in an infra-clinical state.

Various problems are encountered during production of local, deep-seated microwave hyperthermia, involving the technology of the irradiating system, and the complexity of heat transfer in living tissues. Before starting investigations on patients, preliminary studies were conducted on different models. Taking the influence of the blood flow into account, the thermal effects of microwaves were simulated on a numerical model, and a perfused phantom. These studies were completed by investigations in animals. The analysis of findings demonstrates that, in given conditions of irradiation, the temperature distribution is strongly dependent on blood flow. This means that the phantom models are only useful to evaluate the influence of the irradiation parameters and to develop and compare the generator-applicator systems, and that accurate planning of therapeutic trials requires in vivo studies on animals as well as on patients.

Growth rate and heat production of breast carcinomas have been investigated during the natural evolution of 21 untreated cancers, all with small tumour size (greater than or equal to 3 cm) and most of them were treated by surgery (excision of growth, mastectomy). Three original facts have thus been discovered : a) the specific heat power 1 (i.e. the heat quantity generated by the tumour per untis of volume and time, computed from from intramammary temperature and thermal conductivity measurements made using of fluvographic needle probes), is typical of each cancer and re7ains remarkably constant during the growth in spite of themorphological and of the morphological and circulatory changes; b) the tumour doubling time tau2v (calculated from measurements of the tumour size effected at various stages of the evolution by assuming an exponential growth), is univocally related to 1 by a hyperbolic law so that the faster the tumour is growing themore heat generates; c) q is significanty higher and tau2v shorter in all cases where the histological examination has revealed signs of lymphatic dissemination (carcinomatous lymphangitis, lymph node metastases,...). Practically q represents a quantitative criteria useful for setting with objectivity the pre-therapeutical prognosis of cancers clinically classified T1 or T2 and of circumscribed no palpable cancers. Similar but less accurate prognostic information may also be obtained by cutaneous thermography (infrared, liquid crystals) considering the intensity, extent and topography of the skin hyperthermia frequently elicited by the cancer. Thid aid to prognosis of the thermal methods is all the more valuable as the tumour doubling time cannot be evaluated under the customary clinical conditions.

The recent technical and clinical advances in breast thermography are reviewed in this article. Emphasis is placed upon liquid crystal thermal imaging and computer-assisted analysis of breast thermograms. New data are presented concerning the value of thermography for the early detection of mammary carcinomas, the identification of women at high risk of developing breast cancer, and the detection of cancer in fibrocystic breasts.