[Selective and non-invasive monitoring of the posterior columns and pyramidal tract during surgery of the spine and spinal cord]. / Monitorage non invasif et sélectif des cordons postérieurs et de la voie pyramidale pendant les chirurgies du rachis et de la moelle épinière.

For intra-operative neurophysiological monitoring during spine and spinal cord surgery, the challenge is to detect, in real-time, the occurrence of neurological impairment at onset in order to remedy the problem as quickly as possible before it becomes definitely acquired and irreversible. The past three decades were marked by considerable technical progress. Feasibility and reliability have now reached a very high level. A multimodal approach combining simultaneous monitoring of somatosensory and motor pathways has enabled a considerable decline in the rate of false negatives reported in the 80s when somatosensory evoked potentials (SSEP) were monitored alone. Several methods of monitoring are described in the literature. Combining transcranial electric stimulation of muscle motor evoked potentials (mMEP) and cortical SSEP allows non-invasive and selective monitoring of the posterior columns and pyramidal tract. One of the most widely used techniques internationally backed by a broad consensus within the International Society of Intra-operative Neurophysiology (ISIN), this technique remains exceptional in French-speaking countries. We expose here the methodological aspects for the readers of La Revue Neurologique.

Multiple bcl-2/Ig gene rearrangements in persistent polyclonal B-cell lymphocytosis.

Persistent polyclonal B-cell lymphocytosis is a benign lymphoproliferative disorder of unknown aetiology occurring exclusively in women, characterized by typical binucleated lymphocytes, polyclonal expansion of B cells and elevated serum IgM. Owing to the role of Bcl-2 oncogene in inhibition of apoptosis, we have investigated the presence of the bcl-2/Ig gene rearrangement. Bcl-2/Ig gene rearrangement was determined by polymerase chain reaction targeting the usual breakpoint regions of the t(14;18). Bcl-2/Ig gene rearrangement was identified in all six patients and, more importantly, multiple rearrangements were present in five patients. The frequency of the bcl-2/Ig gene rearrangement is estimated to be of one translocation in 1 x 10(2) to 1 x 10(3) peripheral blood mononuclear cells. We conclude that persistent polyclonal B-cell lymphocytosis is associated with bcl-2/Ig gene rearrangement. These findings are of clinical importance because these patients may be misdiagnosed as having a leukaemic expression of non-Hodgkin's lymphoma.

Familial hemolytic-uremic syndrome and homozygous factor H deficiency.

Inherited hemolytic-uremic syndrome (HUS) is unusual. We report the occurrence of HUS in two siblings; one died at an early age while the other (the proband) has presented with three episodes of HUS since the age of 19 years. The finding of a persistently low serum C3 level in this patient led to a thorough evaluation of her complement cascade and a family investigation. The proband and her asymptomatic younger sister were found to have very low serum levels (5% of normal) of factor H, a regulatory protein of the alternative complement pathway. Both patients had low levels of serum C3, factor B, CH50 and VAH50, reflecting persistent alternative pathway activation. The father and mother both had half-normal serum factor H levels but an otherwise normal complement profile. Other members of the extended pedigree were also found to have half-normal serum factor H levels. In conclusion, in this family, factor H deficiency appears to be associated with HUS and is transmitted as an autosomal recessive trait. Persistent C3 hypocomplementemia in the setting of familial and/or recurrent HUS should be a clue to a possible inherited complement deficiency.

The classical and alternate pathways of complement in oral contraceptive users.

Whole complement (CH50), C3, C4, the alternate pathway activity of complement (APH50) and factor B were measured in 159 women currently taking oral contraceptives and in 186 women who were not taking the pill. The mean levels of all components of the complement, except APH50, were found to be elevated in current users compared to non-users. The elevation in serum levels was seen in the first year after initiation of oral contraceptive use. Thereafter, levels changed little with duration of use. Among women who stopped using oral contraceptives, complement levels were similar to those of women who had never used the pill. Results appeared to be similar irrespective of the type of progestagen included in the oral contraceptive. These data provide support for the view that oral contraceptives have no adverse effect on the classical and the alternate pathways of complement.

Erythrocyte mean corpuscular volume during cytotoxic therapy is a predictive parameter of secondary leukemia in Hodgkin's disease.

Mean corpuscular volume (MCV) evolution during cytotoxic therapy was studied in 32 patients with Hodgkin's disease (HD) who developed therapy-related acute nonlymphocytic leukemia (t-ANLL) and in 64 HD controls matched for age, therapy duration, and MOPP (mechlorethamine, vincristine, procarbazine, and prednisone) administration. Maximum MCV during therapy reached 108.3 +/- 8.2 fl in t-ANLL patients and 103.4 +/- 9.1 fl in the controls (P = 0.001). Maximum MCV increase was 26.7 +/- 8.3 fl in t-ANLL patients and 16.6 +/- 8.3 fl in the controls (P = 10(-9). The greatest 3-month increase observed during therapy was 14.8 +/- 6 fl in the t-ANLL patients and 10.1 +/- 4.8 fl in the controls (P = 0.0001). During initial MOPP therapy, the greatest 3-month increase reached 14.1 +/- 5.3 fl in t-ANLL patients and 9.8 +/- 4.5 fl in the controls (P = 0.01). The relative risk of developing t-ANLL was 9 for a MCV maximum increase over 24 fl during therapy, which was observed in 71% of the patients with t-ANLL and in only 22% of the controls. For the greatest 3-month MCV increase over 15 fl observed in 57% of the t-ANLL patients and in 17% of the controls, the relative risk reached 15. This suggests that there is at least one factor, independent from therapy, which predisposes to t-ANLL. MCV evolution during therapy appears useful in determining which HD patients have a high risk of developing t-ANLL.

Preleukemic changes in cases of nonlymphocytic leukemia secondary to cytotoxic therapy. Analysis of 105 cases.

Peripheral blood changes preceding therapy-related leukemia were studied in 105 patients who had received cytotoxic therapy, 53 for Hodgkin's disease and 52 for other cancers. Preleukemic anomalies were observed in 74.3% of the cases, appearing after a mean interval of 68.7 months after diagnosis of the initial cancer. This interval was only 57.5 months in patients aged 50 years or older and only 42.3 months in patients with Hodgkin's disease having received cytotoxic therapy for 6 months or less. The first changes most frequently observed were pancytopenia (24.8%) and isolated erythrocyte abnormalities such as anemia or macrocytosis (18.1%). Involvement of two cell lines, isolated thrombocytopenia or leukopenia, circulating immature cells, monocytosis, leukocytosis, or thrombocytosis were also observed. Therapy-related myelodysplastic syndrome was recognized in 19 patients and myelofibrosis in 3. Median duration of the preleukemic phase was 6 months; 9 months in cases of isolated erythrocyte involvement and 5 months in the other cases. Myelomonocytic or monoblastic leukemia appeared less frequently when the first sign involved erythrocytes only. Hematological surveillance thus appears necessary in all patients having received cytotoxic therapy. Bone marrow study with cytogenetic examination should be performed in cases of persistent peripheral blood abnormalities.

Erythrocyte mean corpuscular volume during cytotoxic therapy and the risk of secondary leukemia.

Erythrocyte mean corpuscular volume (MCV) evolution during cytotoxic therapy of Hodgkin's disease, lymphoma, multiple myeloma, ovarian cancer, and breast cancer was studied. The fastest and the highest MCV increases were observed in the diseases and with the therapies the most frequently involved in secondary leukemia: Hodgkin's disease treated with MOPP (mechlorethamine, vincristine, procarbazine, prednisone), and multiple myeloma and ovarian cancer treated with melphalan. On the contrary, with cytotoxic regimens not linked to a high frequency of secondary leukemia such as CMF (cyclophosphamide, methotrexate, 5-fluorouracil) used in ovarian or breast cancer, MCV increase was moderate. As the MCV increase reflects the bone marrow reaction to cytotoxic therapy, an unusually high increase could indicate bone marrow damages which could lead to secondary leukemia.

Study of erythrocyte mean corpuscular volume during cytotoxic therapy as a predictive parameter of the risk of secondary leukemia in Hodgkin's disease.

Erythrocyte mean corpuscular volume (MCV) evolution was studied during cytotoxic therapy in 12 patients with Hodgkin's disease who developed secondary acute leukemia and in 83 patients with Hodgkin's disease without secondary leukemia as control group. Significant differences were observed in the maximum MCV and in the MCV maximum increase during therapy between the two groups of patients. These differences remained significant between the patients treated with chemotherapy alone and those treated with chemotherapy and radiotherapy. MCV maximum increase greater than 23.9 fl was observed in all patients with secondary leukemia and in only 20% of those without secondary leukemia; it was reached 46.3 months before the first sign of preleukemia. Its value in predicting the leukemic risk in Hodgkin's disease is discussed.

An enzyme-linked immunosorbent assay for the detection of complement components on red blood cells.

A new technic using the principle of enzyme-linked immunoassay (ELISA) has been developed for the detection of complement components on red blood cells sensitized in vivo or in vitro. Using a double-antibody technic, anticomplement antisera (anti-C3c or anti-C3c/C3d) produced in rabbits was incubated with the red blood cells, followed by incubation with antirabbit alkaline phosphatase conjugated antiglobulin. The amount of the enzyme fixed was measured spectrophotometrically by the enzymatic hydrolysis of the substrate PNPP. A calibration curve was made from red blood cells on which complement was deposited by the method of Fruitstone . The technic showed a greater sensitivity than the standard antiglobulin tests and allowed simultaneous qualitative and semiquantitative estimates. The technic can be performed in any laboratory equipped with the standard equipment found in a blood bank, including a spectrophotometer. The authors made a modification of Alsever 's solution, which allowed the safe and stable preservation of complement coated red blood cells for 15 days. Significant positive results were obtained clinically using this technic, while negative or weakly positive reactions were obtained by the conventional antiglobulin tests.

[Changes in the mean corpuscular volume during the cytotoxic treatment of cancer and risk of secondary leukemia. Preliminary results]. / L'évolution du volume globulaire moyen pendant le traitement cytotoxique des cancers et le risque de leucémie secondaire. Résultats préliminaires.

Changes in mean corpuscular volume (MCV) were studied in cancer patients. Vitamin B12 or erythrocyte folate deficiencies were observed in only 9% of macrocytic patients (MCV greater than or equal to 100 fl). Bone marrow study in seven macrocytic patients with normal hemograms and normal levels of vitamin B12 and folic acid, on per os daily cyclophosphamide single agent therapy, showed myelodysplastic features. The highest MCV and MCV increases during therapy among 203 patients were observed in those cancers and cytotoxic therapies most commonly followed by secondary leukemia: Hodgkin's disease treated with MOPP and radiotherapy, and multiple myeloma and ovarian cancer treated with Melphalan. 21 patients who developed secondary leukemia had a higher MCV and a greater MCV increment than the control patients. Differences were significant in Hodgkin's disease. This preliminary report strongly supports monitoring MCV changes during cytotoxic therapy to attempt identification of patients at high risk of secondary leukemia.

C3b inactivator deficiency with immune complex manifestations.

We report a complete C3b inactivator deficiency in a 28-year-old patient referred for bronchiectasis and recurrent pneumonia. In addition to these recurrent infections, previously described with this deficiency, he also had several immune complex manifestations (rheumatoid factor, circulating immune complexes and one episode of serum sickness). The consequences of C3b inactivator deficiency on complement activation, chemotaxis and opsonization, clearance of immune complexes, and on red blood cell sensitization are discussed. The study of the parents showed an autosomal dominant transmission.

Simultaneous occurrence of hereditary C6 and C2 deficiency in a French-Canadian family.

The sera of four sisters were found to lack the sixth component of complement (C6) and the serum of one was also partially deficient in the second component (C2). Two other blood relatives were found to be heterozygous for both deficiencies, while only one sibling had normal values. The father of these eight siblings was heterozygous for C2D and C6D and in the third generation, six children were heterozygous for C6 deficiency was treated for chronic active brucel-transmitted; the C6 deficiency was not linked to the HLA system, while the C2-deficiency segregated with the haplotype A10,B18. The proband, homozygous for C6 deficiency was treated for chronic active Brucellosis and in another sibling with C6 deficiency, toxoplasmosis was diagnosed. Neither bleeding disorders nor a tendency to collagen diseases have been observed and the opsonic activity was normal in the sera of all family members.