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Incidence of pulmonary tuberculosis, a contagious infectious disease, decreases in France with 4934 reported cases in 2013. Tuberculosis remains a global health problem as smear is positive in only 50% cases and culture methods require time. In such a context, genotypic diagnostic tools such as Xpert® MTB/RIF gained interest. This rapid and simple-to-use nucleic acid amplification test allows a diagnosis in two hours and prevents further invasive investigations in pulmonary and mediastinal tuberculosis. Because of its low sensitivity, it cannot be used in pleural fluid. Indirect immunologic tests are of no use to diagnose active tuberculosis disease. Another current area of interest is the emergence of resistant tuberculosis. In France, approximately 100 cases of multidrug resistant tuberculosis and a few extensively drug resistant tuberculosis have been reported in 2014. Even though these forms of tuberculosis are imported, it is crucial to identify hazardous situations and to optimize care of these patients. Xpert® MTB/RIF is again of marked interest here as it detects rifampin resistance with a 95% sensitivity and a 98% specificity. Interpretation of genotypic tests such as Genotype® MTBDR or Xpert® MTB/RIF depends on known detected mutations, although they do not always have a clinical or phenotypic expression. In multidrug resistant tuberculosis, the new drug bedaquiline obtained approval for temporarily use in combination with other molecules when there is no other treatment option. Results of bedaquiline are encouraging but adverse events like QT prolongation or the development of new specific drug resistance should convince clinicians to use it with caution.

Sentinel lymph node (SLN) is a concept but also a technical possibility that can be studied and applied to almost all organs with cancer. For colorectal cancer surgery, some possibilities of using the SLN are possible, other implausible and some completely new especially aware of possible analysis of SLN by a molecular biology technique. The orientation of dissection or "lymph road mapping" can be designed for this case or the surgeon may want to limit his actions, particularly in patients with a history of colonic surgical resection, to keep the digestive function in maintaining vascular axes considered not involved in the metastatic process. The use of the single analysis of SLN to determine the positive or negative status of the cleaning has failed because of the frequency of false negatives in part to the size of colic advanced cancers at diagnosis. The use of "ultra-stading" by multiple section or exhaustion of the block, can lead to reconsider a stage N0 to N1 as a point, if the analysis technique remains in HES. Unlike the "ultra-stading" by RT- PCR or immunohistochemistry was even more discussed and seems not equivalent in terms of prognosis and therefore no giving formally justification for adjuvant therapy. Currently, a new technique for molecular biology, named "OSNA", allows an analysis of all the SLN in less than 45 minutes. It is therefore possible to obtain during surgery analysis of a node with the same level of information than traditional analysis using HES. If this node is positive and if the strategy in case of positive lymph nodes was determined prior for this patient, it is possible to anticipate this strategy and place after colectomy during the same anesthesia, venous access quickly to start postoperative chemotherapy. This new technique for analyzing lymph applied to the SLN opens a new potential application of this concept in digestive oncology.

This review focuses on the role of new tools in the "modern" microbiological diagnosis of tuberculosis. Traditional techniques of microscopy and culture remain essential to diagnostic certainty, but some innovations replace daily the older techniques such as the identification of Mycobacterium tuberculosis complex by immunochromatography or mass spectrometry MALDI-TOF type from positive cultures, or susceptibility testing in liquid medium. New tools that use molecular techniques have become important. They all have in common to optimize the fight against tuberculosis by reducing diagnostic delay. They also allow rapid detection of drug resistance. However, the techniques of gene amplification directly from clinical samples are still less sensitive than culture. Bacteriological diagnosis of tuberculosis disease therefore still relies on the complementarities of different phenotypic and molecular techniques.

Today, microscopic examination and culture are still essential for active tuberculosis diagnosis and therapeutic decisions. Nucleic acid amplification and line probe assays speed up identification and susceptibility testing of mycobacteria in AFB smear positive specimens or in culture. They are also efficient for comparison of M. tuberculosis strains with each other (genotyping). On the other hand, today, molecular tests are not relevant for the diagnosis in smear negative specimens and even more for diagnosis of culture-negative tuberculosis.

During the two last decades, the risk of viral transfusion transmission for some infectious agents (HIV, HCV, HBV and HTLV) has been markedly reduced by improved donor screening, improvements of serological assays and the implementation of minipool nucleic acid testing for HIV-1 and HCV viruses. However, implementation during the year 2010 of nucleic acid testing for the detection of HIV RNA, HCV RNA and HBV DNA in a single triplex assay may provide additional safety, especially after acute infection during the window period. New Procleix(®) Tigris(®) technology (Novartis) allow the French blood screening laboratories to answer their actual requirements in terms of security and throughput and to implement nucleic acid testing in case of emergent risks requiring a direct detection of viruses. Furthermore, Tigris(®) is a fully automated system with high level of security during the analytical process, reducing the number of invalid or non-available results observed with the previous semi-automated technologies. Moreover, renewal of material by fully automated and secure systems, especially for the critical step of sample pipeting, may provide additional safety in blood screening laboratories.

Nucleic acid testing has been routinely performed in all blood donations in France since July 1st 2001. This is the story of a controversial decision. "The unacceptable HIV risk" in the context of the early 2000s influenced the decision. The results achieved over these past 10 years are analyzed given the expected progress of this new screening tool for infectious agents in transfusion. They confirm the relevance of models used by experts in 2000. Out of 22.3 million donations over the period (2001-2009), 22 donations have been rejected because of nucleic acid testing positive for hepatitis C virus (n=11) and human immunodeficiency virus (n=11). Nucleic acid testing has contributed to improve the functioning of the transfusion chain activities in order to ensure the availability of blood products. In terms of reactivity against emerging infectious agents, its role in the West Nile virus (WNV) outbreak is exemplary, but it did not play a similar role in crises of the same order. ALT determination has been stopped thanks to nucleic acid testing. The risk of contamination of the method by amplification products has been confirmed and caution is still required. Nucleic acid testing is being maintained and reached a new milestone in 2010 with the implementation of a full automated system, meanwhile pool screening was given up and hepatitis B virus screening became widespread. Nucleic acid tests will probably be revised when all blood products are pathogen-inactivated.

This review describes current developments for the bacteriological diagnosis of active tuberculosis. It deals mainly with molecular methods, describing their performance and how they can be integrated into more traditional diagnostic approaches. At present, microscopic examination and culture are still essential for the diagnosis of TB and to guide therapeutic decisions. Nucleic acid amplification and line probe assays speed up the identification and susceptibility testing of mycobacteria in AFB smear positive specimens or in culture. They are also efficient for comparison of M. tuberculosis strains with each other (genotyping). On the other hand, at present, molecular tests are not applicable for diagnosis in smear negative specimens and even less so for diagnosis of culture-negative tuberculosis. The use of serology for antibody/antigen detection is not useful and it is not appropriate to assays based on the release of interferon-γ release as they are currently available. Notable progress has been made but more sensitive diagnostic tests for TB are still urgently needed.

From March 1998 to August 2009, 1538 non-respiratory samples collected from 1182 patients, were tested using the Gen-Probe Amplified Mycobacterium Direct Test™ (AMTD). After decontamination procedure, every sample was tested by AMTD and by culture on solid and liquid media. The "Gold-standard" was considered by the combination of culture results and clinical diagnosis. Tuberculosis was present in 17,59 % (208 patients). For theses 1538 non-respiratory samples (225 culture positive samples, 248 AMTD positive), 279 corresponded to tuberculosis. After resolving the discordant results, the sensitivity, specificity, positive and negative values were 89, 99, 99,6 and 97,3 %.

Over the last decade, molecular biology techniques for identifying mycobacteria in pulmonary secretions have become more and more sensitive and rapid, even in smear negative samples. Nuclear amplification techniques also allow the rapid detection of resistance to first or second line anti-tuberculous drugs. The sensitivity of these techniques for non respiratory samples is yet to be determined. The diagnosis of latent tuberculous infection (LTBI) has also increased in sensitivity, specificity and positive predictive value through the use of interferon-γ release assays (IGRAs), which are tending to replace the tuberculin skin test, except for children aged under five. These tests, however, do have limitations which are important for the clinician; especially their inability to distinguish active from latent tuberculosis and their inability, in most circumstances, to exclude a diagnosis of active TB.

To review the molecular genetic techniques currently available for rapid prenatal diagnosis of fetal aneuploidy, as well as those still under investigation.Limited to introductory discussion of rapid aneuploidy detection methods.Medline was searched for articles related to the topic that were published after 1992. This document represents an abstraction of the information.This update was prepared by the Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada approved by the Executive and Council of the Society of Obstetricians and Gynaecologists of Canada.This update provides information about methods of rapid aneuploidy detection using molecular techniques and the evidence supporting their use in prenatal diagnosis. These methods are reliable and cost-effective for detecting the targeted fetal aneuploidies, but are limited in their ability to detect non-aneuploid chromosome abnormalities, some of which are clinically significant.

Extended-spectrum beta-lactamases (ESBLs)produced by clinical strains of Klebsiella pneumoniae were investigated, using isoelectric-focusing and DNA amplification followed by sequencing. A predominance of SHV variants was found. Sequencing identified the genes for the SHV-2a and -12 enzymes, suggesting direct evolution of SHV-12 from SHV-2a.

We attempte through the following overall review pertaining to the basics of PCR techniques (Polymerase Chain Reaction), to introduce the main applications used in veterinary parasitology. A major problem restricting the application possibilities of molecular biology techniques is of quantitative nature. Amplification techniques represent a real revolution, for it makes possible the production of tens, even hundreds of nanogrammes of sequences when starting from very small quantities. The PCR technique has dramatically transformed the strategies used so far in molecular biology and subsequently research and medical diagnosis.

Diagnosis of atypical mycobacterial infections can be facilitated by molecular biology techniques.Two severely immunodepressed patients were admitted for deterioration of their general health status. Bacteriological analysis of histopathologic fragments showed the presence of acid- and alcohol-resistant bacilli. INNO-LiPA MYCOBACTERIA Amplification v2 made it possible to diagnose Mycobacterium genavense infection.M. genavense is a slow-growing atypical mycobacterium. The molecular biology techniques used by INNO-LiPA MYCOBACTERIA V2 permit its swift identification.

The majority of patients with Chlamydia trachomatis infection are not aware of ther infection because they do not have symptoms. Therefore, infected individuals may not be identifiable, and chlamydial infection in men may persis for long periods, and can lead to complications such as epididymitis and prostatis. The large group of asymptomatically infected patients is not only at risk of long-term sequelate but also sustains transmission within communities. In asymptomatic and in chronic or persistent chlamydial infections, the level of Chlamydia is very low, and consequently chlamydial infections have never been easy to diagnose. The diagnosis may be based on cell culture, direct detection bacterial antigens, the nucleic acid amplification tests (NAATs) which have become the method of choice, and on the evaluation of antibody titers against various antigenic constituents. Both systemic and local antibodies in secretions can be detected in C. trachomatis infection. The introduction of assays based on amplification of genetic material has subsequently increased the sensitivity of detecting chlamydial infections and offer the opportunity to use non invasive specimens such as first void urine and semen to screen infections either in asymptomatic subjects or male partners of infertile couples. Cell culture or direct detection of bacterial antigens cannot be used for semen and urine samples and are not sensitive enough to rule out infections. Advantages of NAATs are the ability to detect even a small amount of organisms. This enables a high detection rate for C. trachomatis in symptomatic patients, in asymptomatic individuals with a low number of elementary bodies, and diagnosis of persistent infections.

Nucleic acid testing is carried out in several steps: plasma pooling, nucleic acid extraction, amplification and detection. The target values of temperature, volume and incubation time are mentioned in the initial protocol without giving their limit values. The objective of this work was to determine the range of values in which the test remains positives. So we have tested: 1) the temperature and incubation time of plasma in lysis buffer (37 degrees C +/- 3 et 30 min +/- 10); 2) the influence of volume and incubation time of silica (50 mul +/- 10 et 10 min +/- 5); 3) the variation of the eluate volume after nucleic extraction. We have also studied the influence of the internal control volume variation. For each parameter the assays were performed at sensitivity limit of the technique and repeated several times. Our results showed that: 1) for all parameters evaluated the tests remain positive within a wide range of values; 2) It is not necessary to set up a sophisticated measurement process; 3) the technique is robust.

Every 10 seconds, one person in the world dies of tuberculosis (TB). It is estimated that one third of the world's population is latently infected with Mycobacterium tuberculosis. The proportion of multidrug-resistant strains of M. tuberculosis is increasing at an alarming rate in some parts of the world linked in part with the human immunodeficiency virus epidemic. For these reasons, TB remains a major public health problem, both in less-developed countries and in many industrialized countries, with 8-10 million new cases and 2 million deaths yearly in the world. Clinical, radiological and histological signs are not specific for tuberculosis or for other mycobacterial infections and allow only a presumptive diagnosis. In the same way, the tuberculin skin test is useful if the reaction is strong or phlyctenular because this test depends on various factors as previous BCG vaccination, contact or primary infection and host immune responses. The diagnosis of mycobacterial infection is proved only when bacilli are present in biological samples. Nevertheless, only 50% of cases in adults and 30% in infants have a positive bacteriological result. It seems necessary to develop new methods for a rapid and efficient diagnosis to optimize the therapy and the control of the epidemic. Laboratory testing in the mycobacterium field is experiencing more changes today than ever before. Determining what assays will be most useful to the clinician is a challenge, and acceptance of the new technology is under discussion. Progress in future will be linked probably to the progress of the genomic area. However the incidence rate is higher in less-developed countries, it is also important to develop now techniques possible to use in these countries. This review focuses on the current state-of-the-art resources useful for accurate and rapid laboratory diagnosis of mycobacterial infections.

xxxi, 118 p., 6 appendices ill.

S1: ii, 52 p., S2: ii, 29 p., S3: ii, 24 p., S4: ii, 2 ill.

The male of Phlebotomus (Anaphlebotomus) fontenillei n. sp. is described from Namoroka area (Madagascar). Its belongs to the subgenus Anaphlebotomus: style with four spines, coxite without basal process and paramere with two branches. It shares with P. berentiensis an original and exclusive antennal formula: 2/III-XII which distinguishes them from P. fertei. P. fontenillei n. sp. differs mainly from P. berentiensis by about 40 setae in tuft on the ventral face of the coxite, the length of the genital ducts and the position of the spines on the style. Sequence of the second internal transcribed spacer (ITS2) of the ribosomal DNA (rDNA) is very informative: the male of P. fontenillei n. sp. cannot be linked to the female of P. huberti (male unknown) regarding the size of amplified DNA fragment (459 bp versus 600 respectively) and the high degree of variability. There are few differences (10 mutations) between the sequences of P. fontenillei n. sp. and P. berentiensis which are closely related species.

Mycobacteria are responsible for many human infections, especially species of tuberculosis complex, causative agents of tuberculosis. With nine millions new cases every year, this disease is responsible for more than two millions of deaths. Nontuberculous mycobacteria (e.g. Mycobacterium avium-intracellulare, Mycobacterium kansasii, Mycobacterium xenopi or Mycobacterium ulcerans) can cause infections too, usually in particular clinical settings. Standard diagnosis of mycobacterial infections relies on direct examination and culture. Although culture in liquid media allows the detection of mycobacterial growth at an earlier stage, isolation and phenotypic identification requires several weeks, as does antimicrobial susceptibility testing. Nowadays, molecular tools are available, allowing quicker accurate diagnosis. Detection of Mycobacterium tuberculosis complex by amplification-based tests can be performed directly from clinical samples, although most identifications are successfully after isolation. Several commercial techniques are now available but identification is limited to selected species, at a high cost. Sequencing of genomic targets (such as rrs, rpoB, gyrB, 16S-23S intergenic spacer or hsp65) allows accurate and quick identifications but requires access to a sequencer. Eventually, our better knowledge of the action mechanisms of the different drugs allows genotypic detection of most antibiotic resistances. Indeed, characterization of mutations in specific target genes (such as rpoB, katG, embB, pncA, gyrA or rrl) should be an effective tool for rapid detection of resistance, although this method has only been used so far for rifampin resistance detection. Nevertheless, this approach, limited to reference laboratories, should always be performed in conjunction with antibiogram.

Neurological manifestations of tuberculosis are rare, especially in immunocompetent subjects. The heterogeneity of clinical and radiological features induces frequently a delay for diagnosis. The aim of the study was to describe clinical and radiological presentation of 11 cases of neuro-tuberculosis and to evaluate clinical outcome. We performed clinical, CSF, MRI and outcome evaluation in all patients. We also performed a mycobacterium analysis by polymerase chain reaction (PCR). Patients were 6 men and 5 women with a mean age of 45.4 years. Clinical presentations were meningeal symptoms in 9 cases and focal manifestations in 4 cases. CSF was abnormal in 82 p.cent of cases (protein increase in 73 p.cent, pleiocytosis in 73 p.cent, hypoglycorrhachia in 45 p.cent and hypochlorrhachia in 36 p.cent). The best diagnostic test was PCR (positive in 45 p.cent of cases). CSF cultures were positive in only 2 cases (18 p.cent). Only 2 patients had chest involvement. MRI was abnormal in 64 p.cent of cases showing pseudo-tumor, arachnoiditis, vascular lesions or medullar involvement. Outcome was good in all cases but two (one patient died and one patient had paraplegia possibly related to late diagnosis). Neurological manifestations of tuberculosis are extremely various in terms of clinical and radiological presentation. The best diagnostic test seems to be tuberculosis PCR. Outcome is frequently favorable if late diagnosis is avoided.

The HER2 proto-oncogene encodes a transmembrane protein, which is considered to function as a growth factor receptor. Overexpression of this protein found by immunohistochemistry in about 20% of infiltrating breast carcinomas, has a predictive value of response to treatment by trastuzumab, an anti-HER2 humanized monoclonal antibody. Search for HER2 gene amplification is necessary to adapt the immunohistochemical technique quality and also in the cases of delicate analysis or weak overexpression. It is usually carried out by Fluorescence In Situ Hybridization (FISH). A more recent hybridization technique, named CISH because of its chromogenic revelation is an alternative method, which gives highly correlated results with FISH. We present details of this technique, which may be more familiar for the pathologists than FISH, because reading analysis is similar to that of immunohistochemical staining.

Monitoring trends in residual risk of transfusion-transmitted viral infections is important to assess improvements in blood safety. These trends were analysed over nine overlapping periods of 3 years from 1992 to 2002. The 2000-2002 estimates were compared to the results of HIV-1 and HCV NAT implemented on all blood donations in July 2001.As risk is mainly associated with the window period, residual risks were estimated by multiplying incidence rates by the durations of the window periods. For the first seven periods, incidence rates were calculated from data collected by the blood centres belonging to the Transfusion-Transmissible Agents Working Group which collect more than 50% of blood donations in France, and for the two last periods, on the overall blood supply.On the 2000-2002 period, residual risks without NAT were estimated at 1 in 1,400,000 for HIV, at 1 in 1,000,000 for HCV and at 1 in 400,000 for HBV. With minipool NAT, the residual risk become nearly two times lower for HIV (1 in 2.5 million donations) and seven times lower for HCV (1 in 6.65 million donations). For HIV, of the 4.9 million donations screened with NAT between July 2001 and June 2003, two were remote thanks to the NAT, which is consistent with the NAT expected yield. Concerning HCV, one out of the four WP predicted cases was detected with NAT. Without NAT, the overall residual risk for the three viruses combined (HIV, HCV, HBV) decreased from 1 in 65,000 to 1 in 235,000 donations between 1992 and 2002. Since the implementation of NAT, the current overall residual risk is 1 in 325,000 donations (28% less than without NAT).NAT results confirm the validity of residual risk estimates given by the model, and the limited benefit of genomic screening due to the very low level of residual risk at the time of its implementation.

We report the results of a systematic direct detection screening protocol for Chlamydia trachomatis in urine samples from young women.The study included 1026 patients aged 13 to 30 years. Urine samples were tested with a molecular biology assay: AMP-CT.Thirty-five patients (3.4%) were positive: 80% of the positive patients were aged less than 25 years, 48.6% less than 20 years. All these patients were treated and post treatment controls were negative.This study suggests that national screening programs for Chlamydia trachomatis could be beneficial for women aged between 15 and 25 years and that the "Calmat" law could be modified in consequence.

The nucleic acid amplification methods: Amplicor (Roche diagnostic) and AMTD Amplified Mycobacterium tuberculosis Test Direct-(Gen-Probe) were tested in 278 specimens from 231 patients suspect to be affected by mycobacterial infection. When results of both methods: Amplicor and AMTD were compared with culture results (specimens grow M tuberculosis) and clinical characteristics, the sensitivity and specificity were 91.4% and 97.9% respectively for pulmonary specimens and 61.1% and 98.6% respectively for extrapulmonary specimens. Detection of amplification inhibitors reduce false-negative reactions and control of specimen with microscopic negative and amplification positive, reduce the false-positive reactions. Amplicor and AMTD kits can be used in clinical laboratories. Both assays have the potential to reduce the time of tuberculosis diagnosis to one day.

Since its introduction a decade ago, the polymerase chain reaction (PCR) has been largely utilized as a powerful research tool in microbiology. More recently, the simplification and the automatization of the PCR coupled with the recent development of several other nucleic amplification techniques has brought the introduction of molecular biology into the routine clinical laboratory. The PCR techniques offer new exciting perspectives in the field of microbiology in terms of clinical diagnosis and there are at least three areas in which this technology is expected to have a significant impact in the clinical microbiology laboratory over the next decade : 1) direct detection and identification of organisms that are slow-growing or those currently lacking a system for in vitro cultivation; 2) identification of genotypic markers of microbial resistance to specific antibiotics; 3) direct identification of microorganisms based upon amplification and sequence analysis of common sequence elements. This review also briefly discusses the various problems that must be overcome prior to routine use of PCR in the clinical laboratory.

Progress in molecular biology has led to the development of new tools for bacteriological diagnosis. Sporadic genes coding for virulence factors can be detected with highly specific genetic probes applied to cultured bacteria. Such genetic probes can also be used to specifically identified cultured bacteria whose general taxonomic classification is known. Another advantage of molecular genetics is the possibility that the cell culture step may not be needed, bacteria being identified directly in the sample specimen. Such techniques are particularly interesting to identify bacteria which are difficult to culture (for example: Borrelia burgdorferi, Chlamydia trachomatis) or which grow slowly (mycobacteria). The bacterial DNA must be isolated and amplified with an enzyme reaction. This is a critical step in the method: several positive and negative controls are required. When performed under optimal conditions, amplification techniques are excellent methods which can offer results similar to culture methods in culturable bacteria. Finally, molecular biology can be used to identify previously cultured bacteria for which there is no taxonomic orientation. Here the ribosome 165 DNA must be amplified and sequenced. The sequence is then compared with a data bank allowing classification. One could image future techniques applied to certain pathology samples for the detection and identification of bacteria without need for a culture step. However, direct microscope examination and bacterial culture remain the basic methods for bacteriologic diagnosis, the advantages and disadvantages of molecular biology leading to its use a complementary method for improving the quality of the diagnosis.

The study of the molecular biology of infectious agents involves the examination of their genomes and the products of those genomes. Molecular biology methods may therefore allow us to study either DNAs or RNAs. The study of genomic RNAs (viruses) or messenger RNAs (all infectious agents) is used increasingly in infectious disease pathology. The hepatitis C virus was identified in 1989 and was shown to be responsible for a large number of chronic hepatitis cases in France and worldwide. This virus is a good model for the development of technologies to study RNAs, which will later be applied to the study of other viruses. The molecular biology methods used to study hepatitis C virus RNA may be classified into 3 categories. a) Detection methods evidence nucleic acids in fluid or tissue samples, mainly using the polymerase chain reaction (PCR), but also newly developed techniques, such as the NASBA (nucleic-acid-sequence-based amplification), the Q-beta reaction, and the LCR (ligase chain reaction), and techniques that localize viral RNAs in tissue (in situ hybridization, in situ PCR). b) Quantitative methods determine the amount of RNA present in a sample. These include quantitative PCR and new technologies based on signal amplification, such as the 'branched DNA' assays which have recently been developed. c) Qualitative analysis of the genome uses genotyping methods to classify viral strains into different genotypes and subtypes.

For immunocompetent patients, ocular toxoplasmosis is the most frequent infectious cause of chorioretinal inflammation. Nowadays, the laboratory diagnosis of ocular toxoplasmosis requires serological tests and anterior chamber puncture to detect the local production of specific antibodies. The authors describe a new technique to detect toxoplasma in aqueous humor by a polymerase chain reaction in which the target is a 88 bp specific rDNA fragment. 31 patients were concerned (23 highly suspect of ocular toxoplasmosis and 8 controls). The presence of the parasite in aqueous humor was found in 7 cases. No false positive was detected. The sensitivity of the test is reduced by the poor volume of the sample. The combination of this technique with Desmont's coefficient gives a better positive predictive value. We emphasize the pathophysiological value of this technique by suggesting the presence of tachizoites in the anterior chamber. According to our knowledge, this finding has never been demonstrated. In the future, this should be a very promising technique for the diagnosis of ocular toxoplasmosis.

We extracted and visualized DNA from ancient human teeth and bones of 150 to 5,500 years B.P. from three deposits from the south of France. The DNA extracted was used as template for PCR with specific primers corresponding to a portion of the human mitochondrial genome. In our samples, we have amplified a specific DNA fragment of 121 bp which, in the case of one bone of 150 years B.P. has been cloned and sequenced. We show that this sequence is identical to the homologous region of human mitochondrial DNA. The striking implications of this new method for archaeological and paleontological studies are exposed.