High-risk genotype for type 1 diabetes: a new simple microtiter plate-based ELOSA assay.

The main contribution to genetic susceptibility for type 1 diabetes (T1D) is conferred by the HLA class II genes, with a major involvement of the DQB1*02 and 0302 alleles. The aim of our study was to develop a simple and rapid method suitable for identifying individuals with an HLA-associated T1D risk using whole blood as a source of DNA and reverse hybridization on microtiter plates (ELOSA). DNA was extracted from whole blood using various extraction methods. The PCR-amplified second exon of the DQB1 gene was hybridized at 37 degrees C for 1 hr to a set of 11 capture probes immobilized on a microtiter plate (eight-well strip per test) and corresponding to T1D susceptibility (S), protection (P), or neutral (N) alleles. Colorimetric analysis was then performed using specific oligonucleotides coupled to horseradish peroxidase and OrthoPhenyl Peroxidase (OPD) substrate. DNA samples corresponding to French (Rhône-Alpes area) T1D patients (n = 128) have been genotyped with the HLA-T1D prototype. A strong correlation is observed between susceptible genotypes and the disease, because 92.2% of the T1D individuals screened have at least one susceptible allele (DQB1*02 or *0302), thereby strengthening interest in analyzing DQB1 alleles as HLA-linked T1D markers in our Rhône-Alpes area population. Interestingly, clear T1D-associated genotyping results have been observed when using DNA samples extracted from dried blood spots, making it possible to envisage such genotyping in geographically dispersed affected families, for large-scale newborn screening, and for the inclusion of high-risk patients in clinical trials aimed at preventing the disease.

Influence of adenoviral fiber mutations on viral encapsidation, infectivity and in vivo tropism.

Targeting of adenovirus (Ad)-encoded therapeutic genes to specific cell types has become a major goal in gene therapy. Redirecting the specificity of infection requires the abrogation of the natural interaction between the viral fiber and its cellular receptors (CAR) and the simultaneous introduction of a new binding specificity into the viral capsid. To abrogate the natural affinity of the fiber, we have mutated residues presumed to be directly or indirectly involved in CAR-binding in the knob domain of the fiber protein. These residues are located in the AB loop (Ser408) and in the DG loop (Tyr491, Ala494, Ala503). The mutations Ser408Glu, Tyr491Asp, Ala494Asp and Ala503Asp did not prevent the incorporation of trimeric fibers in the viral capsid but led to loss of CAR binding in vitro. Infectivity of the mutant viruses could be restored in vitro by introducing a ligand at the C-terminal end of the knob, confirming that the reduced infectivity of the fiber-modified virus was due to an impaired interaction of the viral particle with the CAR receptor. However, after systemic delivery, the in vivo biodistribution of impaired CAR-binding viruses without addition of a specific ligand was not altered when compared with wild-type Ad.

Characterization of novel safe lentiviral vectors derived from simian immunodeficiency virus (SIVmac251) that efficiently transduce mature human dendritic cells.

We describe the generation and the characterization of new lentiviral vectors derived from SIVmac251, a simian immunodeficiency virus (SIV). A methodical approach was used to engineer both efficient and safe packaging constructs allowing the production of SIV viral core proteins. SIV-vectors encoding GFP (green fluorescent protein) were generated as VSV-G-pseudotyped particles upon transient expression of the vector construct and helper functions in 293 cells. The SIV vectors were able to transduce efficiently various target cell types at low multiplicity of infection, including monocyte-differentiated human dendritic cells (DCs) which retained their capacity to differentiate into mature DCs after gene transfer. Transduction of the DCs by the SIV vectors was prevented when infections were performed in the presence of AZT, a reverse-transcriptase inhibitor. After gene transfer, expression of the GFP in the target cells remained constant after several weeks, indicating that the vectors had been stably integrated into the genome of the host cells. Preparations of SIV vectors were systematically checked for the absence of replication-competent and recombinant retroviruses but remained negative, suggesting the innocuousness of these novel gene delivery vectors. Side-to-side comparisons with vectors derived from HIV-1 (human immunodeficiency virus) indicated that the SIV vectors were equally potent in transducing proliferating target cells. Finally, we have determined the infectivity of SIV vectors pseudotyped with surface glycoproteins of several membrane-enveloped viruses.

Development of minimal lentivirus vectors derived from simian immunodeficiency virus (SIVmac251) and their use for gene transfer into human dendritic cells.

Lentivirus-derived vectors are very promising gene delivery systems since they are able to transduce nonproliferating differentiated cells, while murine leukemia virus-based vectors can only transduce cycling cells. Here we report the construction and characterization of highly efficient minimal vectors derived from simian immunodeficiency virus (SIVmac251). High-fidelity PCR amplification of DNA fragments was used to generate a minimal SIV vector formed from a 5' cytomegalovirus early promoter, the 5' viral sequences up to the 5' end of gag required for reverse transcription and packaging, the Rev-responsive element, a gene-expressing cassette, and the 3' long terminal repeat (LTR). Production of SIV vector particles was achieved by transfecting 293T cells with the vector DNA and helper constructs coding for the viral genes and the vesicular stomatitis virus glycoprotein G envelope. These SIV vectors were found to have transducing titers reaching 10(7) transducing units/ml on HeLa cells and to deliver a gene without transfer of helper functions to target cells. The central polypurine tract can be included in the minimal vector, resulting in a two- to threefold increase in the transduction titers on dividing or growth-arrested cells. Based on this minimal SIV vector, a sin vector was designed by deleting 151 nucleotides in the 3' LTR U3 region, and this SIV sin vector retained high transduction titers. Furthermore, the minimal SIV vector was efficient at transducing terminally differentiated human CD34(+) cell-derived or monocyte-derived dendritic cells (DCs). Results show that up to 40% of human primary DCs can be transduced by the SIV vectors. This opens a new perspective in the field of immunotherapy.

Gene transfer of anti-gp41 antibody and CD4 immunoadhesin strongly reduces the HIV-1 load in humanized severe combined immunodeficient mice.

OBJECTIVE: To study the anti-HIV-1 effects of the delivery of anti-gp41 monoclonal antibody (mAb) and soluble CD4 (sCD4) immunoadhesin by genetically modified cells in HIV-1-infected, humanized severe combined immunodeficient (SCID) mice. DESIGN: The complementary DNA of mAb 2F5, an anti-HIV-1 gp41 antibody, and of sCD4-IgG chimeric immunoadhesin were transferred into 3T3 cells using Moloney murine leukaemia virus vectors. The cells were then incorporated into a collagen structure called the neo-organ, which allowed the continuous production of the therapeutic molecules. METHODS: The antiviral effects in vivo of 2F5 or sCD4-IgG or both compounds were evaluated in neo-organ-implanted SCID mice that were grafted with human CD4 CEM T cells and challenged with HIV-1 Lai or MN. RESULTS: In SCID mice implanted with 2F5 neo-organs, antibody plasma levels reached 500-2000 ng/ml. Viral loads after HIV-1 challenge were significantly reduced in neo-organ-implanted HIV-infected mice. Although 29 x 10(7) and 13 x 10(8) HIV-1-RNA copies/ml were detected at 12 days in the controls (mice injected with Lai and MN, respectively) less than 16.5 x 10(3) HIV-1-RNA copies/ml were observed in all implanted mice injected with either Lai or MN. The intracellular viral load was also reduced in CD4 cells recovered from the implanted mice. Comparable antiviral effects were obtained with CD4-IgG neo-organs. CONCLUSION: Our results confirm the anti-HIV properties of 2F5 and sCD4-IgG continuously produced in vivo after ex-vivo gene therapy in SCID mice.

[In vitro and in vivo inhibition of HIV1 replication by retroviral transfer of interferon alpha, beta, or gamma genes: application to gene therapy of AIDS]. / Inhibition in vitro et in vivo de la réplication du VIH1 par transfert rétroviral des gènes d'interféron alpha, beta ou gamma: application à la thérapie génique du sida.

Somatic gene therapy is defined as the transfer of a heterologous gene into an organism for the purpose of correcting a genetic defect or providing a new therapeutic function to the target cell and thus inducing a cure or improving associated symptoms. While encouraging results have been generated by recent clinical evaluation of combination of anti-viral drugs, Aids still constitute an obvious candidate among the infectious diseases which might be treated by gene therapy. We have therefore chosen to develop and evaluate a gene therapy strategy based on the transfer into human target cells of HIV1-inducible interferon (IFN) alpha, beta or gamma genes. In a preliminary study, myeloïd U937 cell lines transfected with expression vectors containing the IFN alpha, beta or gamma genes under the control of the long terminal repeat (LTR) sequences of HIV1 were shown to be strongly resistant against an in vitro and in vivo (in HIV1 challenged SCID mice model) HIV1 infection. This cellular resistance was correlated with a strong induction of transgenic IFN synthesis and for IFN gamma, with a defect of HIV particles maturation. Secondly, construction and production of high titer retroviral vectors containing Tat-inducible IFN genes allowed efficient transduction of lymphoïd cell lines and human primary lymphocytes. These transduced cells were shown to be highly resistant against laboratory and primary HIV isolates. Taken together, our in vitro and in vivo results suggest that HIV1 inducible IFN gene therapy can be beneficial to HIV-infected individuals provided the fact that methods are developed that allow the efficient transduction of human hematopoïetic stem cells.

Prenatal diagnosis of Walker-Warburg syndrome in three sibs.

Walker-Warburg syndrome (WWS) is an autosomal recessive condition characterized by diffuse neurodysplasia, resulting in brain and eye abnormalities. We report on 3 prenatally diagnosed cases of this syndrome born to a consanguineous couple. An ultrasonographic examination showed hydrocephalus at the 27th week of the first pregnancy. Amniocentesis documented a normal male karyotype. The couple opted for termination of the pregnancy but declined an autopsy. Seven months later, hydrocephalus was observed at 20 weeks of the second pregnancy. Termination of pregnancy was performed at the 22nd week. Autopsy of this male fetus showed dilated ventricles, thin cortex, and type II lissencephaly with microscopic evidence of chaotic architecture. Eye examination showed retinal dysplasia. Notwithstanding the lack of demonstrable muscle change, the diagnosis of Walker-Warburg syndrome was made. Ten months later, hydrocephalus was discovered in the third fetus, a female, at 13 weeks of gestation. Termination of pregnancy was performed at 20 weeks. At autopsy, brain, eye, and muscular findings were similar to those of the previous case. In addition, cystic changes and a stenosis of the pyelo-ureteral junction were found in the right kidney. Type II lissencephaly and retinal dysplasia are characteristic of WWS. Muscular dystrophy has been pointed out as an additional abnormality in postnatal cases. By contrast, the lack of demonstrable muscle changes in the fetal period must be emphasized. Those cases illustrate practical problems in the ultrasound and pathologic diagnosis of WWS in the fetal period.

Experimental gene therapy: the transfer of Tat-inducible interferon genes protects human cells against HIV-1 challenge in vitro and in vivo in severe combined immunodeficient mice.

OBJECTIVES: To evaluate in vitro and in vivo a strategy for gene therapy for AIDS based on the transfer on interferon (IFN)-alpha, -beta and -gamma genes to human cells. DESIGN: Human U937 promonocytic cells were stably transfected with Tat-inducible IFN expression vectors conferring an antiviral state against infection with HIV. METHODS: Transfected cells were either infected by HIV-1 in vitro or transplanted into severe combined immunodeficient (SCID) mice for an HIV challenge in vivo. RESULTS: U937 cell lines stably carrying IFN transgenes under the positive control of the HIV-1 Tat protein were highly resistant to HIV-1 replication in vitro. This antiviral resistance was associated with a strong induction of IFN synthesis immediately following the viral infection. HIV-1 proteins were found to be specifically trapped within the genetically modified cells. In contrast, all IFN-U937 cells permitted full HIV-2 replication. Transfected cells injected into SCID mice and challenged against HIV-1 were strongly resistant to infection when cells were transduced with IFN-alpha of IFN-beta genes. However, IFN-gamma-transfected cells permitted HIV-1 infection in vivo despite the induction of a high level of IFN-gamma secretion. The quantity of proviral DNA was 10(5)-fold lower in IFN-alpha- or IFN-beta-transfected U937 cells collected from these SCID mice than that in non-transfected cells. CONCLUSIONS: Our results substantiated the validity of a strategy, bases on the transfer of HIV-1-inducible IFN-alpha or IFN-beta genes, to confer antiviral resistance to human cells.

The diagnosis of carpal tunnel syndrome. Sensitivity and specificity of some clinical and electrophysiological tests.

The study group consisted of 100 persons referred with suspected carpal tunnel syndrome. Clinical and neurophysiological examinations were performed blinded from each other. The gold standard for the carpal tunnel syndrome (CTS) diagnosis was based on the results of these examinations but relief of CTS symptoms after surgery was also required. The sensitivity and specificity for the combined results of the clinical examinations were 94% and 80% respectively, and for the neurophysiological examinations, 85% and 87%. Of the neurophysiological methods used, the quotient of sensory nerve conduction velocity between palm to wrist and wrist to elbow was best and the cut-off for this test was studied by means of an ROC-curve. According to our results clinical examination by an experienced doctor seems to be sufficient if there are typical symptoms of carpal tunnel syndrome, but if there is a history of pain, atypical symptoms or earlier fractures in the arm, wrist or hand, it is important to add a neurophysiological examination.

Myoelectric activity in the stomach and duodenum after epidural administration of morphine or bupivacaine.

BACKGROUND: Gastric emptying is delayed in patients receiving postoperative pain relief with epidural morphine compared to patients receiving epidural bupivacaine. The electrophysiological basis for this effect is unknown. The aim of this study was to compare the effects of epidural morphine with epidural bupivacaine on gastroduodenal myoelectric activity (EMG) in patients after surgery. METHODS: Fourteen patients with epidural analgesia who underwent open cholecystectomy were randomly assigned to receive either epidural morphine (EM) or epidural bupivacaine (EB) for postoperative pain relief. During surgery EMG electrodes were placed in the subserosa in the antrum and duodenum and the EMG registration started 3.5 hours after the end of surgery. Gastric emptying measured with the acetaminophen test was studied in the morning the day after surgery. RESULTS: The spike activity in the antrum was significantly lower 160-340 minutes after the administration of morphine in the EM-group compared to the activity in the EB-group (P < 0.04). The incidence of regular slow wave rhythm in the antrum was significantly lower 160-520 minutes after the administration of morphine in the EM-group compared to the EB-group (P < 0.03). Duodenal Phase III activity measured with EMG was significantly more frequent during 160-520 minutes after the morphine administration in the EM-group compared to the EB-group (P < 0.02). The acetaminophen absorption was significantly delayed in the epidural morphine group compared to the epidural bupivacaine group. CONCLUSIONS: Gastroduodenal electromyographic activity was significantly changed during epidural morphine compared to epidural bupivacaine. The delayed gastric emptying during epidural morphine may be explained by decreased and uncoordinated contractile activity in the antrum, shown by decreased spike activity and irregular slow wave rhythm. The increased pressure activity in the duodenum, shown by increased Phase III activity, may also impair gastric emptying.

Evaluation of epidural sensory block by thermal stimulation, laser stimulation, and recording of somatosensory evoked potentials.

BACKGROUND AND OBJECTIVES: The existence of differential sensory block during epidural analgesia has been confirmed by some authors and disputed by others. This study attempts to elucidate this issue by using quantitative methods for evaluation of sensory block. METHODS: A single epidural injection of 20 mL 0.5% bupivacaine with epinephrine was administered at the L1-T12 level in 11 male volunteers. Sensory block was evaluated by two qualitative (pinprick and light touch) and two quantitative methods (thermal stimulation with Thermotest [Somedic, Stockholm, Sweden] and argon laser stimulation). For measurement of motor block in the lower extremities and in the rectus abdominis muscle, quantitative methods were used. Sensory block was also assessed by somatosensory evoked potentials recorded during electrical and laser stimulation at the most cranial analgesic dermatome (loss of sharpness in pinprick perception) and the anesthetic dermatome L2 (loss of light touch perception). RESULTS: The zone of anesthesia was smaller than the zone of any other investigated variable. The cranial spread of analgesia and motor block was lower than that of laser-assessed block. Partial block of laser perception and thermal perception lasted longer than analgesia and motor block. No consistent segmental or temporal differences were found between the Thermotest and laser methods. During epidural block, prolongation of latencies and reduction in amplitudes of somatosensory evoked potentials produced at the most cranial analgesic dermatome did not differ significantly from those produced at the anesthetic dermatome. CONCLUSIONS: No differential block of small nerve fibers was found during epidural analgesia by Thermotest and argon laser stimulation. Recording of somatosensory evoked potentials did not demonstrate significant difference between responses from the sites with most superficial and with most intense sensory block.

F response and H reflex for monitoring nerve block during epidural analgesia with ropivacaine.

The effect of a single epidural injection of ropivacaine on the motor and sensory function controlled from the L5/S1 level was investigated in 28 male volunteers. Concentrations of 1%, 0.75%, or 0.5% ropivacaine, 20 mL, administered at the L2/3 level were studied. Motor function was assessed quantitatively (measurement of muscle force by mechano-transducers), and sensory function by the pinprick method. In addition, F response and H reflex, tests which measure the conduction velocity in the central parts of peripheral nerves, were used. Epidural ropivacaine caused dose-dependent prolongation of the latencies of both these variables. F response latency recovered significantly later than motor function measured by mechano-transducers in the two lower concentration groups. H reflex latency recovered significantly later than sensory function assessed by the pinprick method in all three concentration groups. The time needed for recovery of F and H latencies was not significantly longer than the time from epidural injection to mobilization. At the time when the subjects could go through the mobilization procedure, 12 of 28 subjects were not completely recovered. In 5 of these 12 subjects, the H reflex latency was persistently prolonged at the end of the investigation, long after the subjects felt "normal" again. On follow-up recordings 5 mo later, the baseline latency had been regained in all five subjects. We conclude that F response and H reflex latencies are good indicators of the inhibition of nerve impulse conduction induced by epidural analgesia.

Blockade of the abdominal muscles measured by EMG during lumbar epidural analgesia with ropivacaine--a double-blind study.

A single shot of 20 ml of 1%, 0.75% or 0.5% ropivacaine was administered epidurally (at L2/3 level) to 30 volunteers, in a double-blind manner. The blockade of the rectus abdominis muscle was measured quantitatively by registration of the average rectified electromyographic signal (AREMG) at the T7, T9 and T11 motor segmental levels and with a qualitative test for blockade of the rectus abdominis muscle (the so-called RAM test). The maximal cranial spread of analgesia, evaluated by the pin-prick method, was not significantly different for the three concentrations (T8-T10 dermatome; median value). The intensity of motor blockade, measured by the AREMG method, increased progressively from the T7 segment and caudally with all three concentrations. The blockade was partial (i.e. 85-25% of baseline AREMG activity was present at its maximum) in all subjects. When the effect of the three concentrations of ropivacaine was compared at the same segmental level, the intensity and duration of maximal motor blockade seemed to be dose-dependent, but the difference was not statistically significant. The total duration of motor blockade was shorter with the 0.5% solution than with the higher concentrations. The AREMG method gave a more exact and graded picture of blockade of the rectus abdominis muscle than the RAM test. The duration of sensory blockade did not outlast motor blockade at any level. In half of our subjects the maximal spread of sensory blockade was either equal to or higher than the spread of partial motor block. In the other half, this relationship was reversed--the maximal cranial level of partial motor block was 1-4 segments higher than the maximal level of analgesia.

Epidemiology of neuromuscular diseases, including the postpolio sequelae, in a Swedish county.

The epidemiology of neuromuscular diseases was studied in the county of Orebro, Sweden (study population 270,000). Several different sources of data were utilized, compared and validated. On the prevalence of day (January 1, 1988) 474 patients were identified. The rate per 100,000 population was 92 for the postpolio sequelae (PPS) and 84 for the other neuromuscular diseases (motor neuron disease 9, hereditary neuropathies 9, myoneural disorders 16, myotonic disorders 19, muscular dystrophies 20 and myositis 11). Of the patients with the PPS, 80% reported late-onset symptoms. On the basis of an expanded survey including all medical records in one health care district, the prevalence of the PPS was estimated to be 186/100,000 population.

Behavioral medicine treatment in chronic constipation with paradoxical anal sphincter contraction.

Nine women and five children with severe chronic constipation received behavioral medicine therapy. Before treatment, all patients had a paradoxical contraction of the external anal sphincter at defecation attempts as demonstrated with electromyography and/or anorectal manometry. An electromyographic biofeedback device connected to an anal probe was used for the training that was performed on a regular toilet seat during five 1-hour sessions. Thirteen of the patients improved considerably and could learn to defecate spontaneously, and the use of laxatives ceased or diminished. Simultaneously with improvement, the paradoxical anal contraction disappeared. The results remained after 6 months, although two of the patients had received booster sessions of biofeedback training during follow-up.

The serum reserve albumin concentration for monoacetyldiaminodiphenyl sulphone and auditory evoked responses during neonatal hyperbilirubinaemia.

Auditory brainstem evoked responses (ABR) were recorded in 9 neonates with hyperbilirubinaemia. Pathological recordings were found in two children showing absence of waves and prolonged latencies. There was no correlation between latencies to waves and the total serum bilirubin concentration. The serum reserve albumin concentration for monoacetyldiaminodiphenyl sulphone (MADDS) was, however, inversely related to the latencies in the ABR recordings. Our findings suggest that the binding properties of serum albumin contribute to the risk of bilirubin toxicity and that, in this study, the reserve albumin concentration for MADDS seemed to be of greater significance than the total bilirubin concentration.

Influence of intravenous local anaesthetics upon quadriceps muscle function.

This study was undertaken to assess the effects of intravenous administration of mepivacaine and etidocaine on muscle function. Seven male volunteers were given mepivacaine (5 mg/kg) and etidocaine (50 mg) intravenously, on separate occasions. A reference group of 11 male volunteers received 0.9% saline solution intravenously. Muscle function was tested by measurements of isometric muscle force of knee extension and by quantitative electromyographic (EMG) recordings from the quadriceps muscle during knee extension at different degrees of isometric muscle force. At the end of the mepivacaine and etidocaine infusions, the mean venous plasma concentrations of the two anaesthetic agents were 2.9 and 1.2 micrograms/ml, respectively. The muscle strength remained unchanged during infusion of the two local anaesthetics. Mepivacaine had a minor effect on the mean rectified EMG amplitudes at the end of the infusion at maximal voluntary muscle contraction, but no such effect was observed at submaximal knee extension force. However, at the plasma concentrations mentioned above, the clinical influence of intravenous infusion of the local anaesthetics on muscle function was negligible.

Motor blockade and EMG recordings in epidural anaesthesia. A comparison between mepivacaine 2%, bupivacaine 0.5% and etidocaine 1.5%.

In a double-blind study young volunteers randomly received 20 ml of mepivacaine 2%, bupivacaine 0.5% or etidocaine 1.5% epidurally, all solutions with adrenaline. The mean cephalad spread of pin-prick analgesia was equal (T10) in the groups, but the duration was longest for bupivacaine and etidocaine. The motor blockade of the rectus abdominis muscles was assessed quantitatively by rectified integrated electromyographic recordings (RIEMG) and as number of turns in EMG recordings [changes in the direction (rise/fall) of the EMG; TURNS] from three different segmental levels, T7, T9 and T11. The motor blockade of the quadriceps muscles was estimated by EMG recordings simultaneously with muscle force measurements at maximal isometric knee extension. Motor blockade was also evaluated by the Bromage scale. There was good correlation (correlation coefficient 0.91) between RIEMG values and muscle force in knee extension during epidural anaesthesia. TURNS showed a non-linear relationship to isometric force during epidural anaesthesia and added no further information. At the lower parts of the abdomen (T11), etidocaine gave more profound and longer motor blockade than mepivacaine. For quadriceps muscle function, motor blockade was almost complete with all three local anaesthetics; the duration of maximum motor blockade was short (45-60 min) for mepivacaine, but about 5 h with etidocaine. At the time when the Bromage scale indicated complete regression of motor blockade, the muscle force of knee extension was only 30% and the quadriceps RIEMG 35% of control values and 1-3 h remained until the time of mobilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of motor blockade by isometric force measurement and electromyographic recording during epidural anaesthesia--a methodological study.

Methods for assessing motor blockade by means of isometric force measurements and surface electromyographic (EMG) recordings in the lower extremities and abdominal wall were evaluated in 30 volunteers. The coefficients of variation were 10% for force measurements and 14% and 20% for average rectified EMG (RIEMG) recordings over the quadriceps muscle and abdominal muscles, respectively, and 8% overall for TURNS (the number of changes in the sign of the direction of the EMG signal). Seven of the 30 volunteers received epidural anaesthesia with 20 ml of mepivacaine 2% with adrenaline. The mean maximal cephalad analgesic level was T9. At that abdominal segment, RIEMG showed a reduction of 50% and TURNS of 20%. Isometric force and RIEMG recorded simultaneously in the quadriceps muscles during epidural anaesthesia displayed a linear relationship with a correlation coefficient of 0.91. TURNS was insensitive to force variations above 60% of maximum voluntary contraction. During the regression phase, 90% of both the initial force and RIEMG value was noted 180 min after the epidural injection. It is concluded that recording of RIEMG is a good method for quantitative assessment of motor blockade during epidural anaesthesia.