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This double-blind randomized study vs placebo in healthy male and female volunteers demonstrates the positive biologic effect on hair loss and hair regrowth of a pulsed electromagnetic field in combination with essential oils administered according to a regular treatment schedule of 26 weeks. Mean hair count comparisons within the groups significantly favor the treatment group, which exhibited a decrease in hair loss in 83% of the volunteers and a more than 20% hair count increase over baseline in 53% of patients. The process exhibited no side effects or untoward reactions. The histologic examination correlated with the clinical study. A parallel immunohistochemical examination showed an increase in the proliferation index, and when the expression of Ki67 (a cell proliferation marker) is increased, the mitoses are barely visible in the histologic examination. The rationale of this phenomenon is considered to be due to an electrophysiologic effect on the quiescent hair follicle.

The effects of testosterone on the relative proportion of Thy 1.2, CD4 (L3T4) and CD8 (Lyt-2) cells in thymus and spleen were studied after castration and administration of Depo-testosterone (DT) separately or together with cyproterone acetate (CA) (an antiandrogen) in BDF1 mice. Injection of 0.5 mg/100 g body weight of DT during 2 weeks decreased significantly the number and proportion of double positive (DP) (CD4+ CD8+) and increased the percentage of single positive (SP) CD4+ (CD4+ CD8-), whereas there was a slight decrease in the Thy 1.2+ cells in the thymus. In parallel, we observed an increase in CD8+ (CD4- CD8+) cells in the spleen. The androgen deprivation after 3 weeks of castration induced a decrease in the percentage of CD4+ cells in thymus and both CD4+ and CD8+ cells in spleen. Injection of CA (0.5 mg/100 g body weight) had the same qualitative effects as DT on the proportion of lymphocyte T subsets in castrated mice. However, the combined activities of DT and CA were greater than either alone. These data indicate the main role of testosterone in the distribution of CD4+ and CD8+ cells in male mice. The similar effects of CA and DT in the lymphoid organs may suggest a difference between androgen receptors of sexual and lymphoid organs.

We describe three cases of acute myeloid leukaemia revealed by diabetes insipidus. The patients were 42, 38 and 39 yr old and they had marked hyperleukocytosis, circulating immature granular cells and a normal or elevated platelet count. The leukaemia was type AML-M2 according to the FAB classification. Cytogenetic studies showed inversion of chromosome 3 (q21;q26) in 2 cases and a translocation (3;3)(q21;q29?) in the remaining case, both associated with monosomy 7. All the cerebral CT scans were normal. Complete remission was never achieved, and all three patients survived less than 14 months. Desmopressin therapy was active but treatment could not be reduced. The association of dysmegakaryopoiesis with a chromosome 3 abnormality and diabetes insipidus is probably not fortuitous and could represent a new entity.

In oncology, flow cytometry (FCM) and image cytometry (ICM) are commonly used to detect DNA aneuploid cell populations in solid tumors. Agreement between these two approaches is good. The use of both techniques in association minimizes the rate of FCM and ICM false negatives and gives better DNA pattern characterization, particularly for detection of any tumoral component in the FCM DNA diploid peak. Nevertheless, discrepancies exist between the FCM and the ICM DNA index values: the ICM DNA index is often greater than the FCM DNA index. The aim of the present study was to establish a cytogenetic DNA index by determining the chromosomal ploidy using a molecular cytogenetic approach and to compare it to the FCM and ICM DNA indexes. We present here the fluorescence in situ hybridization (FISH) technique we have adapted to the study of breast cancer in order to count the number of copies of the 22 + X human chromosomes in interphasic nuclei. This was achieved using a panel of 21 indirect FITC labeled probes which recognize specific chromosomic DNA sequences. Preliminary results obtained from DNA diploid and DNA aneuploid tumors are discussed.

The interrelationships between proteasomes and viral gene products are very complex. 20S proteasomes associate with a number of viral mRNAs which are cleaved by proteasome's associated endonuclease activity. In addition proteasome's endopeptidase activities are involved in the presentation of viral antigens. Viral proteins of different origin associate with the 20S and 26S complexes and interfere with their enzymatic activities. A major part of this review deals with the interactions between 20S proteasomes and the gene products of the human immunodeficiency virus (HIV) which has been studied in detail by our group.

The present study has focused attention essentially on the Parsis, an ethnic group with high breast cancer incidence. We have investigated the potential use of prosomes, compared to Ki-67 and PCNA, as an additional cell proliferation marker. We also addressed the question whether or not breast tumors of Parsis differed in their DNA index and in the proportion of the S-phase fraction, compared to that of non-Parsi and European patients. We observed that the benign tumors of Parsis and non-Parsis were hyperdiploids, whereas in case of malignant tumors the Parsis showed essentially diploid characteristics while hyperdiploidy prevailed in the non-Parsis. Tetraploidy was seen as a common feature in the non-Parsis, whereas aneuploidy seemed to be the more common type in the Parsis. The cell cycle analysis also revealed some interesting differences between the cell proliferation compartments of these two populations. A high number of cells in G2+M and S-phases was seen for non-Parsi malignant tumors while only the S-phase had a large cell count in the Parsis malignant tumors. The malignant tumors of Parsis and non-Parsis showed, as would be expected, a high expression of Ki-67 in the proliferation compartment. Surprisingly high Ki-67 expression was also a feature seen in the benign tumors of Parsis only and not any other group. We observed that expression of Ki-67, a proliferation marker directly related to the degree of malignancy, paralleled that of prosomal protein expression. In addition the prosomal monoclonal antibodies appeared to be more sensitive than Ki-67 in detecting a larger quantum of cells in the proliferation compartment.

The core of the 26S proteasome, the 20S prosome, is a highly organized multi-protein complex found in large amount in malignant cells. Differentiation of several cell lines, including the monoblastic U937 and the lymphoblastoid CCRF-CEM, is accompanied by a general decrease in the prosome concentration when phorbol-myrirtic-acetate (PMA) and retinoic acid plus dihydroxyvitamine D3 (RA+VD) are used. Incubation of U937 cells for three days with PMA or RA+VD causes differentiation, but the resulting patterns of prosome labeling in the cell and on the plasma membrane are not the same. In contrast, the same kind of prosome changes occur in U937 and CCRF-CEM cells when PMA is used as inducer. The intracellular distribution of prosomes is also linked to malignancy and differentiation. Prosomes are found in the nucleus and the cytoplasm of cancer cells; and treatment with RA+VD decreases the prosomes in the nucleus whereas PMA causes various prosome proteins changes. These results indicate that prosomes are important in cell regulation and in the expression of malignancy.

Epidemiological studies have revealed that Parsi women have a higher incidence of breast cancer than non-Parsis and that they are more susceptible to breast cancer. We have studied the cellular distribution of two prosomal proteins p23K in parallel to the p30.33K and proliferation marker Ki-67 as potential markers to identify high risk population for breast cancers. Flow cytometry data demonstrated that the Parsi benign and non-Parsi malignants have a higher number of cells labelled with these two prosomal protein antibodies than the non-Parsi benign and European 'normals'. Using immunohistochemical methods, p23 K was found to be significantly higher in Parsi and non-Parsi malignants as well as in non-Parsi benigns. In our FCM analysis, intergroup comparison showed, interestingly, a significantly higher expression of both p23K and p30.33K in Parsi benigns as compared to non-Parsis, raising the possibility that benign tumors of Parsis represent already premalignant lesions. The present study, in addition, proposes the prosomal antigens as likely cell proliferation markers comparable to Ki-67.

The inflammation is characterized by a multifrequency time structure described both in the edematous reaction and in the migration of neutrophilic polymorphonuclear (PMN) in the inflammatory site. The circadian rhythm of PMN migration appears to be similar when the migration was induced by BCG, LPS or carrageenan. The corticosteroids play an important role in the mechanisms in the circadian rhythm of PMN, but recent data in intact and castrated mice indicated that testosterone is also involved in these mechanisms. In arthritic patients, the signs and symptoms of the diseases varied as a function of time of day and of the type of arthritic diseases. Human data with indomethacin, ketoprofen and piroxicam indicated that it is possible to find an optimal time of day for the administration of these non-steroidal anti-inflammatory agents (NSAID). Clinicians can use these chronopharmacological data to maximize the analgesic effect and to minimize the side effects of the NSAID. The research on biological rhythms in inflammation and in the effects of NSAID lead to a better understanding of the mechanisms of inflammation and to the rational use of the drugs in arthritic patients.

We have previously shown that the chemical agent of myeloid differentiation, dimethyl sulfoxide (DMSO), causes apoptosis in human leukemic U937 cells (Château et al. Anal. Cell. Pathol. 1996;10:75-84). Activation of protein kinase C (PKC) by phorbol 12-myristate 13-acetate (PMA) led to inhibition of the DMSO-induced apoptosis, suggesting that PKC helps regulate this mechanism by preventing cell death. However, specific inhibitors of PKC (bisindolylmaleimide, D sphingosine), neither triggered apoptosis themselves, nor affected the DMSO-induced apoptosis. Surprisingly, herbimycin A, a potent inhibitor of tyrosine kinases, did not trigger apoptosis itself, but it did prevent DMSO-induced nuclear fragmentation, whereas okadaic acid, an inhibitor of protein phosphatases, triggered apoptosis in U937 cells. These results suggest that DMSO-induced apoptosis requires the activation of an unidentified tyrosine kinase that is probably down-regulated by PKC activation.

Dimethyl sulfoxide (DMSO), which induces differentiation of myeloid cells, was found to cause apoptosis in human leukemic U937 cells. Apoptosis was assessed by DNA electrophoresis and flow cytometry. The time needed to induce apoptosis varied from a few hours to 2-3 days, depending on the concentration of DMSO used. The plasma membrane remained intact long after DNA fragmentation had occurred. DMSO-induced apoptosis was inhibited by zinc ions and, to a lesser extent, by the protein kinase C activator: phorbol 12-myristate 13-acetate (PMA). Cycloheximide and actinomycin D did not prevent DMSO-induced apoptosis, showing that U937 cells do not require protein or RNA synthesis to undergo apoptosis. DMSO induced apoptosis despite the expression of the anti-apoptotic Bcl-2 protein in U937 cells. The amount of Bcl-2 remained unchanged during DMSO-induced apoptosis.

The DNA content of lepidopteran cell lines infected with densovirus was determined by flow cytometry. Vital DNA production was monitored and in vitro viral cytopathogenic effects were analyzed. The increased fluorochrome binding was linked to an increase in viral DNA content and to alteration in the nucleus structure observed under electron microscopy. The information provided by flow cytometry was complemented by ultrastructural studies.

The inflammatory reaction is characterized by a multifrequency time structure with prominent circadian, ultradian and circannual rhythms in cell proliferation and cell function. The chemotaxis of polymorphonuclear neutrophil leukocytes (PMN) appears to be an important effector mechanism in the defenses against external antigenic agents. Granulocytes are present in large numbers in inflammatory reactions and their numbers are also increased in chronic inflammatory diseases. Numerous models have been used for analyzing the mechanisms of inflammation because any single one cannot express the whole inflammatory process of disease. Many pharmacology studies indicate circadian and circannual changes in drug effectiveness and toxicity. The mechanisms underlying these changes are not fully understood yet, but there is evidence indicating that time-dependent variations in the metabolism of drugs and in drug pharmacokinetics may partly explain them.

The activities of three mycotoxins isolated from the hyphomycete Metarhizium anisopliae: destruxin A, B, and E (DA, DB and DE) are described and compared in vitro on leukemic cells. Their antitumor effect was investigated by flow cytometry on growth, cell viability and cell cycle perturbation 48 h after destruxin exposure. Against P388 leukemic cells, DE displayed greater antiproliferative activity than DA and DB. The minimum concentration required to inhibit 50% of cell proliferation is 0.33 microgram/ml for DE, 11.7 micrograms/ml for DA and 9.4 micrograms/ml for DB. Cell cycle modifications were only observed with DE at 50 and 10 micrograms/ml and consisted in an accumulation of the cells in G0/1 phase. DA and DB did not modify the number of cells in G0/1 of the cell cycle. Nevertheless a decrease in the number of cells in G2+M phase was induced by the three destruxins.

The time course of polymorphonuclear neutrophil (PMN) migration in an experimental inflammatory granuloma induced by carrageenan in the mice was studied at 6 different times of the day. Compared to saline, the number of PMN increased as soon as 240 min and reached high level at 480 min when migration was induced by carrageenan. The data showed circadian variations in the time course of cell migration. After 240 and 360 minutes of migration, the number of PMN was highest in the cell trap implanted at 09.00 whereas minimum values were obtained at 01.00. After 480 minutes of implantation, the PMN migration was maximal when the carrageenan experiment was performed at 05.00 and minimum values were obtained at 13.00. Thus, a significant rhythm was demonstrated in the time course of PMN migration.

This study was performed to determine whether temporal variations could exist in polymorphonuclear neutrophil (PMN) migration induced by LPS or BCG in mice. LPS- and BCG-impregnated cell traps were implanted at 6 different times of the day and removed after 480 min. The PMN number per square unit (mm2) was counted and the results were expressed as means +/- S.E. in 8-10 mice. The results showed that nycthemeral variations occurred in both LPS- and BCG-induced PMN migration. Between 5.00 and 9.00 h a maximum value of 4210 +/- 270 and 1920 +/- 486 PMN/mm2 were obtained with BCG and LPS respectively; at 17.00 h a minimum value of 1300 +/- 270 with BCG and 396 +/- 127 PMN/mm2 with LPS were observed. There was no significant nycthemeral variation in saline-induced PMN migration.

The cervical cytologic screening is responsible for the overall decline in the incidence of cervical cancer. Despite this apparent success, the cytologic assessment by light microscopy of cervical smear has recently been shown to have deficiencies particularly in cervical intraepithelial neoplasia (CIN). Now, this pathology of the uterine cervix is increasingly becoming recognized as a major health problem in young women because of its high frequency and its association with the development of cervical carcinoma. Flow cytometry (FCM) is widely used as a rapid method to analyse DNA content of a great number of cells on a cell by cell basis. The authors have applied FCM to CIN in order to reinforce the cytologic screening of cervical smears. Three abnormal DNA patterns have been observed: increased and heterogeneous DNA pattern; increased S and G2+M phases; abnormal DNA content. The statistical calculation has emphasized the significant relation linking these DNA patterns with the cytologic diagnosis and the severity of CIN. Therefore, FCM is a powerful complementary tool in cervical pathology.

The thymic and splenic reactions, following injections of BCG and living Brucella M. in the guinea pigs, were studied. Both microorganisms injected intravenously produced thymic involution, maximal after BCG inoculation, followed by regeneration that was complete by day 10 in Brucella M.-treated guinea pigs, and by day 15, in BCG injected guinea pigs. Increase of mitotic index was more accentuated and more persistent after Brucella M. than after BCG treatment in the thymus. After a short involution period the spleen of injected animals increased in size in both groups. The splenic enlargement was dramatic and occurred at an accelerated rate in animals given BCG. It appeared to be the result of a conspicuous involvement of the red pulp by multiple granulomas. In Brucella M. treated guinea pigs the splenic enlargement was less obvious, but the splenic white pulp was more abundant in BCG-treated guinea pigs. Granulomas were observed only in the periarterial sheaths of the white pulp. These observations provide evidence for the hypothesis that injections of both BCG and Brucella M. provoke a proliferation of B and T lymphocytes, a migration of T lymphocytes from the thymus to the T-dependent area of the spleen which seems, perhaps, more marked after injection of Brucella M., and a strong granulomatous histiocytic reaction which is more conspicuous in animals given BCG.

A new method, employing a skin-implanted cell trap already used to study chemotaxis in cancer patients, was applied to 35 healthy volunteers and 12 psoriatic patients. A dacron disk impregnated with 10 microliters of 4-6.10(6) live BCG suspension was implanted in the deep dermis. After 24 h the disk was removed, and five sections of each disk were counted for polymorphonuclear leukocytes (PMNs) and monocytes. Involved and uninvolved psoriatic skin showed a decrease of PMN migration into the disk as compared with controls. No difference could be demonstrated between involved and uninvolved skin. Mononuclear cell chemotaxis was the same in psoriasis as in controls. These results are in agreement with other in vivo data using mainly the skin chamber technique indicating a decrease of PMN chemotaxis in psoriatic skin at 24 h.

Three types of laser radiation were compared as to their capabilities in hepatic surgery using 17 New Zealand rabbits. In four animals, subtotal scalpel lobectomy was performed, the hepatic pedicle being clamped. Hemostasis is obtained by means of argon or Nd YAG laser as long as the internal diameter of the vessels encountered is less than 4.5 mm. Nd YAG laser requires a power output four times higher than argon laser to obtain hemostasis. In six animals limited resection was performed by means of Nd YAG and CO2 lasers. CO2 radiation supplied insufficient hemostasis whenever the vessel diameter was more than 1 mm despite an excellent cutting power. Nd YAG radiation created an important necrosis zone due to thermal diffusion. In seven animals various focal hepatic lesions produced by the three types of laser were compared. Argon laser induced superficial and regularly round lesion, Nd YAG laser deeper, cauliflower-like lesions with thermal diffusion following especially vessels. Veins presented thrombosis of their blood content and coagulation necrosis of their wall. The amount of glycogenic granulation discreased. The CO2 laser induced very sharp punctual lesion without necrosis. Electron-microscopic sections revealed faint shadowy liver cells closet to the thermal source and bubbled mitochondria containing disrupted critea around the lesion. In later lesions Nd YAG laser produced more extensive fibrosis than argon or CO2 laser. After first clinical trials we believe that laser irradiation is actually an adjuvant safety factor in current hepatic surgery, whereas the Nd YAG laser could be of real interest in metastatic carcinoma destruction in liver.

The results indicated that i.v. injection of fresh BCG induced in the guinea-pig thymus a transient increase of lymphocyte mitosis associated with an epithelial hyperplasia in the cortex on day 10. Changes in the medulla were more obvious on day 15. The hyperplasia of Hassall's corpuscles and epithelial cells in the medulla reached its maximum level at a time when many lymphocyte masses appeared in the splenic red pulp and in the T area of the spleen. Evidence suggesting an active secretory function in their external cells was recorded. These findings were consistent with the hypothesis that BCG produces an increase of new lymphocytes input into the T lymphocyte cycle.

When a small dacron sponge disc containing live BCG was implanted subcutaneously in healthy subjects it became infiltrated with leukocytes which at 24 hours mainly involved neutrophils. this mycobacterial-induced inflammatory response was markedly impaired in patients with cancer. This inhibitory effect could be reproduced by injecting the plasma of these patients into guinea-pigs bearing identical discs. The differences in inflammatory reactions in the indirect technique were less marked than in the direct test, though a parallelism between the two was seen. The fact that the plasma from cancer patients interferes with neutrophil responses in this way does not exclude the possibility that abnormal cellular functions were also operative. Since tumour growth control depends on effective inflammation these data further underline the importance in cancer patients of a defect at this level.

The authors study the epidemiological conditions of the appearance of Burkitt's disease on the Ivory Coast. This condition represents 4.12% of cancers observed in this country. From a thorough study of the differences in temperature, relative humidity, vapour pressure, hours of sunlight, amount of rainfall, they were able to pick out that equatorial forest zones are more at risk than the savannah zones. The climatic conditions in the forest render intervention by a vector plausible, either directly or indirectly via malaria or other parasitic infestations.

The migration of inflammatory cells and fibroblasts into dacron mesh tissue (Mersilene), immersed in a suspension of live BCG and implanted s.c. into intact male and female guinea-pigs treated with either commercial or purified human chorionic gonadotropin was investigated. Cell counts showed that in treated animals a significant reduction (about 70%) of whole cells occurred. The effect was maximal on neutrophil granulocytes (a reduction of 85%) by Day 5 after grafting. No significant differences appeared between males and females or between commercial and purified human chorionic gonadotropin.

Monthly changes in the migration of polymorphonuclear leucocytes (PMN) produced by subcutaneous implantation of BCG-impregnated rayone-made disks was examined over a period of 15 months. In experiments carried out at 90h00, the highest PMN count of 40.2 +/- 8.4 PMN/10,000 micrometers2 10,000 micrometers2 was obtained in April. Mechanisms that could explain the circannual variation are suggested.

The activity of destruxin E, a cryptogamic toxin isolated from the hyphomycete Metarhizium anisopliae, was studied on mouse leukemia cells (L 1210 and P 388) in culture. Besides a cytotoxic effect, a cytostatic effect (increase of diploïd cells proportion) was observed with all doses for P 388 (from 10 micrograms/ml to 0.001 microgram/ml) and to a concentration of 0.1 microgram/ml for L 1210. At the lower doses, the effect on cellular DNA content appears distinctly.

The morphological effects of liver resection in 15 pigs performed with a Nd-YAG laser beam are reported. A regular cut surface was obtained and overlayed an ischemic layer which was thinnest at a 80 W power output and a short exposure time. Hemostasis was satisfying when the encountered vessels did not exceed 4,5 mm in diameter. Semi-thin and electron microscopic examination showed "ghost" cells in the layer of coagulation necrosis, shrunken hepatocytes and red blood cells in oedematous layer and "swollen" mitochondria in the deepest layer. Clamping of the hepatic pedicle - increasing local hyperthermia by suppression of cooling vascular inflow - majorated the depth of cellular alterations and the intensivity of the post-operative inflammatory reaction. Numerous biliary ductules and active hepatocytes meant parenchymal regeneration. Good healing evolution free of complications was observed after a one year's follow up.

Disturbances of folic acid metabolism can bring about the appearance of characteristic displastic cells, FD cells, in the cervico-vaginal epithelium. A study of the colpocytogram in a series of patients who had trophoblastic tumours treated with methotrexate shows that the administration of an antifolic agent can provoke under certain conditions the appearance of FD cells or an increase in their number when they are present before chemotherapy has been started. These cells are in a variable percentage of cases, transitory in nature but when methotrexate treatments are repeated they often return as a regular feature. The cytomorphologic aspect of these FD cells when they appear after chemotherapy is identical to those that exist spontaneously in certain deficiency conditions occuring in pregnancy and the puerperium.

The inflammatory reaction is characterized by a multifrequency time structure with prominent circadian, ultradian and infradian rhythms in cell proliferation and cell function. The circulating blood cells show highly reproducible circadian rhythms in human and in animals. Daily fluctuations of concentrations of haematologic chemical and endocrinological parameters are described. Circannual variations of several hematologic parameters are presented. Chronobiological studies of plasma exudation in carrageenan paw oedema show a circadian and a circannual rhythm. Daily and annual changes in migration of polymorphonuclear leucocyte produced by BCG are studied in mice. Differences in response are observed in adrenalectomized and castrated animals. The susceptibility of cells and tissues at different stages of their circadian or circannual rhythms lead to the development of a chronotherapy of inflammation.

Liver resection is performed in 15 pigs by means of low divergent Nd YAG laser, the hepatic pedicle being clamped and not. Clamping does not modify the efficiency of laser hemostasis during resection but increases the thickness of the ischemic layer underlying the cut liver edge. The coagulation necrosis and the edematous layer are more thickened. Migration of inflammatory cells and young fibrosis present at day 3 are gaining ground until day 15. During the same period, biliary neoductules and nodules of hepatic regeneration appear. Hepatic inflow being conserved, these reactions are delayed and less intensive. The hyperthermia, the inflammatory cellular reaction and the deepness of parenchymal damages induces by pedicle clamping are suitable for antitumoral surgery. Cooling effects of hepatic inflow are better for traumatic surgery.

Flow cytometric analysis of cell DNA content in the mouse C 57 BL/6 shows better results with fine needle aspiration than with mechanical dissociation of the tissues. There is no difference fresh and deep frozen stored tissues. In the liver, it has been found two cell populations with different DNA content including diploid and tetraploid cell lines. In the spleen and the thymus, only diploid cells are encountered with different cell cycles belonging to the organ.

The infiltration by inflammatory cells of dacron mesh tissue containing live BCG, implanted under the skin of male and female guinea-pigs treated with normal control and cancer patients' plasmas, was investigated. These cells migrated from the blood vessels to the peri-implant region under the influence of local chemotactic mechanisms generated by the bacilli. Animals given normal or cancer patients' plasmas were unable to produce normal levels of cellular infiltration. This was more markedly reduced with plasma from patients with malignant disease. Cell counts in treated animals have shown significant reduction in while-cell counts but the more marked effect was seen on the polymorphonuclear neutrophil level. Ketoprofen restored normal infiltration responses to animals simultaneously given plasma from cancer patients. These observations further underline the importance of prostaglandins in both inflammation and malignant disease.

Through flow cytometry cells are investigated by optical, electrical and electronic components. On a rate of several hundred cells per second, quantitative multiparametric cells studies are realized on a cell by cell basis. Cells in monodisperse suspension are drawn by a stream of fluid which aligns them before their interception by a beam of light, generally produced by Laser. The generated optical signals (diffused lights and emitted fluorescences), related to biological properties of the cells, are conveyed to photomultipliers which transform light energy into electric currents. The signals are quantified by electronic and processing components which can drive cell sorting. Flow cytometry is playing an increasingly significant role in the practice of the clinical laboratory in several areas i.e. oncology (DNA content measurement) or immunology (lymphocytes phenotyping).

Two properties of the laser beam can be used in medicine: coagulating and sectionning. The possibility for the beam to reach its target through an optic fibre, adaptable to the broncho-fibroscope, enables its use in bronchology. Two patients with a malignant tracheo-bronchial tumour received this treatment. Results were encouraging. Some practical applications are proposed.

Monthly changes in the migration of polymorphonuclear leucocytes (PMN) produced by subcutaneous implantation of BCG-impregnated rayone-made disks was examined over a period of 15 months. In experiments carried out at 90h00, the highest PMN count of 40.2 +/- 8.4 PMN/10,000 micrometers2 10,000 micrometers2 was obtained in April. Mechanisms that could explain the circannual variation are suggested.