Analysis of immunoglobulin secretion by lymph organs with myasthenia gravis.

OBJECTIVES: To investigate in vitro anti-acetylcholine receptor (AChR) antibody secretion by lymph organs with myasthenia gravis (MG) with special attention to clinical status and stages. MATERIALS AND METHODS: Twenty MG patients before therapy were included in this study. Four patients were negative for serum anti-AChR antibodies (AChRAb). All patients received extended thymectomy. Thymic cells, bone marrow (BM) cells and peripheral blood mononuclear cells (PBMC) were cultured for 1 week. AChRAb secretion and IgG secretion in the culture medium were determined by immunoprecipitation assays and ELISA respectively. RESULTS: PBMC secreted AChRAb and IgG most efficiently, followed by BM cells, and then thymic cells. Even in patients whose diseases were of short duration (less than 2 months), the tendency was not changed. AChRAb secretion by BM cells and PBMC significantly correlated with serum AChRAb levels. Thymectomy did not change AChRAb or IgG secretion by PBMC within 3 months. AChRAb secretion by PBMC paralleled the clinical status. Some seronegative patients turned positive by culturing PBMC. CONCLUSION: PBMC is the most efficient site at producing AChRAb, even in patients of short duration (equal to, or less than, 2 months). Monitoring AChRAb secretion by PBMC is useful to estimate the autoimmune activity of MG.

[Relationship between identified patient (IP) with alcoholic problems and familial factors: in reference to family function, co-dependence, family group and self-help group participation].

In 1994, a survey was conducted to 105 wives of alcoholics (identified patient: IP) about levels of their family adaptability, cohesion, co-dependence, family group and self-help group participation. In 1995, a follow-up survey was conducted to the same wives. 87 wives responded to the follow-up questionnaire. 17 responses were excluded due to too many missing responses. Statistical analyses were therefore conducted to the remaining 70 subjects. The following results were found. 1) Balanced as opposed to extreme levels of cohesion were associated with abstinence. 2) Family system changes on cohesion and/or adaptability dimensions were associated with abstinence. 3) Wife's over-involvement with drinking husband somewhat appeared to be related to continuation of drinking. As for participation in family group or self-help groups, there was no significant difference between abstinence and drinking groups.

Familial neurilemoma of the spinal cord in a mother and daughter.

Neurilemoma of the spinal cord occurred in a mother and daughter. Case 1 was a 75-year-old woman with gait disturbance. Examination revealed weakness of the lower extremities, and magnetic resonance (MR) imaging showed an intradural extramedullary tumor at T12. After laminectomy, the histologic diagnosis was mixed Antoni type A and B neurilemoma. Case 2 was a 48-year-old woman (daughter of case 1). She presented with cervical pain and numbness of both hands. Examination revealed weakened intrinsic muscles of the right hand and paresthesia of the right upper arm. MR imaging showed a giant hourglass-shaped extradural tumor at C2 and C3. The histologic diagnosis was Antoni type A neurilemoma. Only six families with neurilemoma have been reported, including our patients. Gene analysis of such patients may clarify the etiology of neurilemoma.

Foreign body gonitis caused by a broken poly-L-lactic acid screw.

Poly-L-lactic acid (PLLA), a biodegradable polymer, is generally considered to be gradually degraded without causing any severe tissue reaction. However, we encountered a patient who developed foreign body gonitis caused by screw breakage after fixation of an intercondylar prominence fracture with PLLA screws. This case suggests that care should be taken when PLLA materials are used to fix intraarticular fractures.

A 17-Mer self-peptide of acetylcholine receptor binds to B cell MHC class II, activates helper T cells, and stimulates autoantibody production and electrophysiologic signs of myasthenia gravis.

We have identified in an extracellular segment of the alpha1 subunit of nicotinic acetylcholine receptor (AChR) of homologous muscle a 17-residue autoantigen that, without conjugation to a carrier, activates Th lymphocytes and induces production of autoantibodies that cause electrophysiologic signs of experimental autoimmune myasthenia gravis. A panel of overlapping synthetic peptides revealed two T cell epitopes, one encompassed by residues 121-136 and the other by 129-145. Residues 129 (glutamic acid) and 130 (isoleucine) were implicated in a pathogenic B cell epitope. Peptide 129-145 (Glu-Ile-Ile-Val-Thr-His-Phe-Pro-Phe-Asp-Glu-Gln-Asn-Cys-Ser-Met-Lys, a conserved sequence in rat and human AChR) induced autoantibody production in 76% of rats. All seropositive rats had evidence of experimental autoimmune myasthenia gravis; five of five tested had electrophysiologic signs, and all had loss of immunochemically measured autologous muscle AChR. Analogues of 129-145, with single residues substituted by alanine, revealed phenylalanine 135, phenylalanine 137, and glutamic acid 139 as most important determinants of Ag/MHC-II/TCR interactions; phenylalanine 137 is critical for T cell activation. B cells were the major MHC-II-positive cell type to which the self-peptide 129-145 bound in a population of nonimmune splenic cells. More efficient processing and presentation of the Th cell epitope by an expanded population of immune B cells selected by specifically binding another epitope of the same peptide would greatly amplify the production of autoantibodies. Peptide autoantigens of this type could plausibly perpetuate the autoantibody response in myasthenia gravis, and are a rational target for strategies aimed at Ag-specific therapeutic intervention.

Does arthroscopic abrasion arthroplasty promote cartilage regeneration in osteoarthritic knees with eburnation? A prospective study of high tibial osteotomy with abrasion arthroplasty versus high tibial osteotomy alone.

The purpose of this prospective study was to determine whether or not abrasion arthroplasty promotes cartilage regeneration in osteoarthritic (OA) knees with eburnation. Patients with OA knees were divided into a group of 51 knees treated by osteotomy with abrasion arthroplasty (Group A) and another group of 37 knees treated by osteotomy alone (Group B). Regeneration of cartilage was compared between the groups both arthroscopically and histologically. The Outerbridge classification was used for arthroscopic grading with Grade 0 being normal and Grade IV representing eburnation. On arthroscopic examination, around 12 months after surgery, Group A showed a significantly higher incidence of Grade II repair (a smooth articular surface and small fissures) and a lower incidence of Grade IV repair than Group B on both the femoral (P < .001) and tibial (P < .01) joint surfaces. Age was the only factor influencing the grade of tibial cartilage in Group A. Histological examination showed that 64% of the regenerated tissue studied consisted of fibro-cartilage at around 12 months after surgery. There was no difference in the clinical outcome at 2 to 9 years postoperatively between Groups A and B.

A new method of hemostasis for cementless total knee arthroplasty.

Heavy bleeding often occurs following cementless total knee arthroplasty (TKA) and it is difficult to control. We devised a new method of hemostasis after cementless TKA. In brief, the implant was inserted after coating the exposed surface of the cancellous bone with fibrin glue. Before removal of the tourniquet after completion of the operation a cocktail of hemostatic agents (containing 25 mg of carbazochrome sodium sulfonate and 250 mg of tranexamic acid) in 50 ml of physiological saline was injected into the joint cavity via the drain tube and the drain was clamped for about 30 min after removal of the tourniquet. After removal of the clamp, standard negative pressure suction was performed. This method was used on 84 knees in 42 patients who underwent simultaneous bilateral cementless TKA and 64 knees in 64 patients who underwent unilateral TKA. The mean total amount of blood loss during and after the operation was 235 +/- 178 ml in the unilateral TKA patients and 402 +/- 208 ml in the bilateral TKA patients. No patient required blood transfusions postoperatively. This method was effective for achieving hemostasis after cementless TKA.

[Molecular immunology of voltage-gated calcium channel and Lambert-Eaton myasthenic syndrome].

Lambert-Eaton myasthenic syndrome(LEMS), an autoimmune disease that is often associated with small cell lung carcinoma(SCLC), impairs the quantal release of acetylcholine by directing antibodies against voltage-gated calcium channels (VGCC) in the motor nerve terminal. We focused attention on the P/Q type VGCC, to which there are antibodies in LEMS patients in higher frequency than antibodies to other types of VGCC. To search for antigenic sites in the molecular structure of alpha 1A subuuit of P/Q type VGCC in LEMS, we synthesized 4 peptides corresponding to the extracellular region (S5-S6 linker) of each of 4 domains that form alpha 1A subunit of VGCC. Also, LEMS patients' sera were studied by immunoprecipitation assay using these antigens. Peptides corresponding to the extracellular region (S5-S6 linker) of domains II and IV were specifically reactive with LEMS antibodies; their titiers respectively correlated with those of anti-P/Q type calcium channel (omega-conotoxin MVIIC-sensitive human cerebellum extret). Lewis rats were immunized with the domain II S5-S6 linker peptides conjugated with KLH. The immunized rats showed LEMS features characterized by reduced acetylcholine quantum content of endplate potentials and antibodies reactive with P/Q type VGCC. Our observations suggest 2 potential epitopes of LEMS antibodies. Synaptotagmin is a Ca2+ and phospholipid binding protein integrated in synaptic vesicle membranes. It plays a crucial role in neurotransmitter release, probably as a Ca2+ sensor for exocytosis of synaptic vesicles. The extracellular region of synaptotagmin was found antigenic for the induction of a rat model of LEMS. A proportion of human LEMS antibodies reacted with the recombinant synaptotagmin in immunoblot.

Antibodies to recombinant synaptotagmin and calcium channel subtypes in Lambert-Eaton myasthenic syndrome.

Several proteins have been postulated as possible targets of immune attack in Lambert-Eaton myasthenic syndrome (LEMS). Heterogeneity of autoantibodies in sera from 20 LEMS patients was studied by comparing their reactivity to synaptotagmin, a synaptic vesicle protein, and voltage-gated calcium channels (VGCCs). Six patients' sera (1 with small cell lung carcinoma (SCLC)) contained antibodies specifically recognizing the recombinant synaptotagmin on immunoblots. Thirteen (11 with SCLC) and 16 (11 with SCLC and 1 with poorly differentiated cell carcinoma in the lung) patients' sera immunoprecipitated omega-conotoxin GVIA-labeled N-type and omega-conotoxin MVIIC-labeled Q-type VGCCs, respectively. Three of 6 synaptotagmin-positive sera had cross-reactivity with N and/or Q subtypes of VGCC; the remaining 3 showed no cross-reactivity with VGCCs. Results indicate that LEMS sera are heterogeneous in the spectrum of containing antibodies, and suggest that this heterogeneity reflects the immune response to various synaptic proteins including not only multiple VGCCs but also synaptosecretory complex proteins.

[Age changes in the lumbar spine: radiological follow-up studies over more than ten years].

To determine the morphological changes due to aging in the lumbar spine and lumbar intervertebral disc, radiological follow-up studies were performed for 245 subjects over more than 10 years. The results were as follows: 1) Disc narrowing increased with age and was not related to sex or occupation, 2) the occurrence and progression of disc narrowing were different between the upper and the lower lumbar discs. Severe disc degeneration was noted in the L4/5 disc. The growth of osteophytes in the lumbar spine was more progressive in males and in physical laborers but was not related to disc narrowing. Since all discs did not become narrow at a constant rate with aging, then disc degeneration should not be considered as a purely aging change, but should be regarded as partly related to aging. Causal factors of disc degeneration should be further investigated on genetic and environmental aspects in each individual case. The occurrence of ankylosing spinal hyperostosis (ASH, Forestier) was not related to disc narrowing. This study supported the concept that ASH was a different entity from disc narrowing although both changes sometimes occurred in combination together.

S-adenosyl-L-methionine ameliorates reduced local cerebral glucose utilization following brain ischemia in the rat.

The average values of the local cerebral glucose utilization (LCGU) were approx. 35-110 mumols/100 g/min in various nuclei in the brain of sham-operated animals. The values, however, were decreased by 25-75% in all areas examined at 24 hr after 4-vessel occlusion (forebrain ischemia) for 0.5 hr. Particularly, the LCGU values in the forebrain nuclei such as the cerebral cortices and thalamus were severely reduced, while that in the nuclei in the midbrain and hindbrain such as the red nucleus, chochlear nucleus and vestibular nucleus were slightly reduced. In rats treated with S-adenosyl-L-methionine (SAM, 100 mg/kg, i.p.) every 1 hr for 6 times from the recirculation, however, the LCGU values were increased in all brain structures by 35-195% in the forebrain ischemic rat. A significant increase was observed in the cerebral neocortices, caudate-putamen, lateral septal nucleus, thalamic nuclei, substantia nigra, cerebellum and some other nuclei. In some forebrain structures whose LCGU were mildly reduced to approx. 60-70% by the ischemia, SAM recovered the LCGU to more than 90% of the value in the sham-operated group. Thus it was concluded that SAM ameliorated widely ischemia-induced reduction of LCGU in the rat.