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Biomedical subjects

N Halperin

Publications and source records attributed to N Halperin.

At least 37 records · Page 2Linked to original sources
PubMed1996

Resurfacing of goat articular cartilage by chondrocytes derived from bone marrow.

The feasibility of using cartilaginous implants containing bone marrow derived chondrocytes in biological resurfacing procedures for correcting defects in articular cartilage was examined in goats. The experimental protocol included bone marrow aspiration, mesenchymal cell culturing, cell proliferation, favorable conditions inducing chondrogenic differentiation, and implantation of autogeneic and allogeneic cells. Autogeneic implant transplantations proved to be the best source for regeneration and repair of defective articular surfaces with use of densitometric computed image analysis of histochemical and immunohistochemical parameters on tissue sections. Allogeneic chondrocyte enriched cultures derived from bone marrow evoke a typical immune response in the host, expressed by the formation of fibrosis and progressive joint arthrosis. In the current study, a biological resurfacing procedure is described in detail for large mammals of similar weight and size as humans. Autogeneic mesenchymal cells derived from a bone marrow aspiration are the best cell source and when embedded in hyaluronic acid based adhesive glue make an excellent cartilaginous implant. The reparative regenerated cartilaginous tissue outcome within the defects appear different than neighboring normal articular cartilage shortly after surgery. Whether in the long term the cartilaginous remodeling process will shape the cartilage such that it more closely resembles the original articular cartilage is not known.

Animals↗
PubMed1995

[Ciprofloxacin-associated bilateral acute achilles tendinitis].

Bilateral achilles tendinitis developed in a 40-year-old man following treatment with Ciprofloxacin, 500 mg twice a day, for prostatis. The signs of tendinitis resolved 6 weeks after cessation of the drug. In recent years very few cases of this rare complication have been reported. In some cases it results in a torn achilles tendon. If diagnosed early, complete recovery usually follows about 6 weeks after cessation of the drug.

Achilles Tendon↗
PubMed1995

[Delayed diagnosis of posterior dislocation of the shoulder].

Posterior dislocation of the shoulder is rare. It may follow trauma, electroconvulsive treatment or an epileptic attack. Correct diagnosis may be delayed, as there is no obvious deformity in the shoulder region and the arm is held in a natural sling position. AP X-ray of the shoulder shows only a few minor signs. A high index of suspicion, proper physical examination, and oblique X-ray views lead to correct diagnosis. Closed reduction is possible if the dislocation is of less than 3 weeks duration. Open reduction is indicated in young patients, and in older patients when there is disability.

Humans↗
PubMed1994

Maffucci's syndrome--the result of neural abnormalities? Evidence of mitogenic neurotransmitters present in enchondromas and soft tissue hemangiomas.

BACKGROUND: Maffucci's syndrome (MS) is distinguished by the enigmatic association of benign cartilaginous bone tumors and soft tissue hemangiomas. METHODS: This study was conducted to define the distribution of nerves and neuropeptides around these tumors. Results were measured by quantitative image analysis of immunohistochemical staining. Four types of tissues were compared: connective tissues around normal muscles, solitary hemangiomas, MS hemangiomas, and MS enchondromas (the last two from a single patient). RESULTS: The number of nerves was found to be quadrupled in both types of hemangiomas as compared to normal connective tissue. A unique feature of MS tissues is the presence of an increased number of nerve fibers not only in the lesions but also in histologically normal margins of resection surrounding the lesions. Furthermore, hemangiomas of both types were found to contain a significantly higher number of calcitonin gene-related peptide-, substance P-, and methionine enkephalin-positive fibers than did normal muscle or its related fibroconnective tissue. These neuropeptides are mitogens, and their presence stimulates the growth of the abnormal blood vessels. Enchondroma fragments from an MS patient contained numerous methionine enkephalin-positive nerves. This neuropeptide is known to act as a growth factor in cartilage proliferation. CONCLUSIONS: A neural abnormality of the neuropeptidergic nervous system seems to relate to the abnormal tumors seen in MS.

Calcitonin Gene-Related Peptide↗
PubMed1994

Automated percutaneous discectomy for reherniations of lumbar discs.

Ten patients with lumbar disc reherniation at the same level as the one previously openly operated on were treated by automated percutaneous discectomy (APD). The results after follow-up for 2.5 years, on the average, showed 70% with complete or significant pain relief, 60% with motor deficit improvement, and 22% with improvement of sensory deficit. Included among the patients who had pain relief were two of three in whom discography had produced only a small amount of pain, but only one of two in whom the contrast material showed contained epidural leak. To reduce the unsuccessful results, patients with segmental instability or spinal stenosis after open surgery should not be treated by APD.

Adult↗
PubMed1994

Changes in femur dimensions in asymptomatic non-cemented hip arthroplasties. 20 cases followed for 5-8 years.

We assessed changes in proximal femur diameter during 5-8 years follow-up of 20 clinically successful press-fit cementless isoelastic implants. Total bone diameter, medullary diameter and cortical thickness were measured over the distal half of the prosthesis and just beyond the prosthesis tip. During the follow-up period total bone diameter did not change. However, cortical thickness declined by an average of 1 mm, while the size of the medullary canal increased by the same amount. As the patients remained asymptomatic during this period, the phenomenon observed did not appear to be related to loosening. We concluded that age-related changes in bone diameter can lead to widening of the tight interface between the stem and the femur.

Adult↗
PubMed1993

In vitro construction of cells-containing implants for articular cartilage regeneration.

Regeneration of destroyed articular cartilage can be induced by transplantation of cartilage cells into the defects. The best results are obtained by the use of either fetal allogeneic cells or autogenic ones. Induction of chondrogenesis in residual mesenchymal cells is optimal for obtaining large amounts of autogenic chondrocytes. Further modification of the technique is needed to reconstruct large defects. The cells are grown on biodegradable scaffolds and are later implanted into joint defects.

Animals↗
PubMed1993

Implants composed of carbon fiber mesh and bone-marrow-derived, chondrocyte-enriched cultures for joint surface reconstruction.

The current study integrates two distinct approaches in joint resurfacing into a combined type of implant, composed of carbon fiber mesh impregnated and coated with a hyaluronic-acid-based delivery substance containing cultured cells. Rabbit autogeneic chondrocyte-enriched cultures obtained from mesenchymal stem cells (chondroprogenitor cells) derived from adult rabbit bone marrow were grown in vitro under conditions favoring chondrogenesis. The improvement in quality of repair when a combined implant containing both cells and a carbon scaffold was used, in comparison to the utilization of carbon fiber mesh alone, was clearly demonstrated using clinical, histological, biochemical, and biomechanical examinations. Evaluations of the joints were performed at 6 weeks and 6 months after implantation. The repair tissue in the cell-implanted joints consisted of a typical hyaline cartilage, which was more cellular and thicker than the repair tissue in the hyaluronic-acid-impregnated carbon-fiber-implanted control joints. The hyaline cartilage in the experimental group formed a superficial layer above the carbon fibers, flush with the joint surface. In the controls, in which carbon fiber and the delivery substance alone were implanted, a histologically and biochemically fibrous tissue that was inferior biomechanically to the new cartilage was formed by the cells containing implants.

Animals↗
PubMed1993

Bone density in old chickens' metaphyses, as affected by local trauma and chondrocyte implantation.

Resurfacing of joints by chondrocyte implants often leads to an increased subchondral bone density. To further evaluate this phenomenon, this study analyzed bone density and bone formation in three groups of 3-year-old chickens (90 animals, 30 per group): (1) implantation of chondrocytes embedded in hyaluronic acid (HA) into the tibial metaphysis; (2) implantation of delivery substance only; (3) sham-operated control group. Results were assessed biochemically, histologically, and histomorphometrically at 6 weeks and 6 months postimplantation. A 1.5-fold increase in the metaphyseal bone density was observed in the HA-implanted controls, as compared to sham-operated/normal joints. A further increase in bone density to twice the density of the sham-operated joints was achieved by implantation of chondrocytes. In bones implanted with cells, long-lasting (6 weeks) cartilage nodules were observed, which eventually underwent hypertrophy. The implanted chondrocytes were surrounded by a dense inflammatory infiltrate, which did not prevent the induction and formation of new bone. Based on these findings, it was concluded that chondrocyte implantation into bones results in an increase in local bone density due to a prolonged process of endochondral ossification. Further studies are necessary to evaluate the possible application of this implantation procedure in osteoporosis.

Animals↗
PubMed1992

Neuropeptidergic innervation of intramuscular hemangiomas.

Intramuscular hemangiomas are idiopathic lesions which are either tumoral or developmental in origin. A close association of abnormal blood vessels with nerve fibers is found and may suggest that nerves have a primary inciting role in the development of these lesions. In the current study, the number of nerve fibers in different zones around the tumors, as well as the type of neuropeptides present in these fibers, was quantitatively assessed by computer-assisted image analysis of immunohistochemical staining of histological slides. The number of nerve fibers as determined by positive staining by anti-protein S-100 antibodies was found to be elevated in the immediate vicinity of the abnormal blood vessels. The density of the nerve fibers rapidly declined with increasing distance from the hemangiomas, reaching normal values at distances of over 2 mm. Furthermore, hemangiomas contain a significantly higher number of calcitonin gene-related peptide (CGRP), substance P, and Met-enkephalin-positive fibers. The most significant rise in number is that of CGRP-positive fibers. This neuropeptide is a known mitogen, which could be responsible for the growth of the hemangiomatous blood vessels. Substance P is a nociceptive neurotransmitter and its presence can explain the pain which often accompanies even tiny intramuscular hemangiomas.

Adolescent↗
PubMed1992

Medial epicondylectomy in cubital tunnel syndrome: an electrodiagnostic study.

Prospective analysis of 27 medial epicondylectomies in 22 patients with McGowan grade I ulnar neuropathy demonstrated an improvement in clinical symptoms. In all patients a N.C.V. study, in which compression of the ulnar nerve at the cubital tunnel was evident, has been a prerequisite for operation. Conduction velocity across the cubital tunnel averaged 48% of normal (26.4 +/- 8.7 metres per second) preoperatively and increased to 85% of normal (46.7 +/- 9.7 metres per second) postoperatively. A preoperative N.C.V. study allows the achievement of a high success rate, especially in the less well clinically defined group of patients with grade I neuropathy (subjective complaints without any objective signs of muscle atrophy). Medial epicondylectomy is safe and predictable in the treatment of cubital tunnel syndrome.

Adult↗
PubMed1992

Restoration of pinch in ulnar nerve palsy by transfer of split extensor digiti minimi and extensor indicis.

Subcutaneous transfer of the ulnar slip of the extensor digiti minimi (EDM) to the adductor tubercle across the dorsum of the hand restores pinch, and index finger abduction is reproduced by re-routing extensor indicis proprius around the thumb extensor tendons. Six patients with post-traumatic ulnar palsy have been treated by this method with a minimum follow-up period of 40 months. Pinch was improved from an average of 5% to 40-50% of the normal side, and index abduction to 30-40%. There was no donor morbidity.

Adult↗
PubMed1992

The use of the transpillar posterolateral approach to resect cervical osteoid osteomas: operative technique and results.

Osteoid osteomas located in the cervical spine are a rare cause of cervical and shoulder pain. However, successful diagnosis of these tumors has become more frequent in the recent years. This is due to more available diagnostic modalities as well as to physician awareness of the possibility that such lesions can cause cervical pain syndrome. Resection of osteoid osteomas located close to the vertebral artery is often technically difficult, and poses significant risk to the patient. We describe resection of such tumors using a posterolateral transpillar approach in three patients. The advantage of this approach is the direct and relatively easy visualization of the tumor, without the need for an extensive dissection. The stability of the cervical spine is not compromised by this approach. However, extension of the operative field is difficult, should the need arise.

Cervical Vertebrae↗
PubMed1992

Anterior compartment syndrome of the thigh in athletes--indications for conservative treatment.

Anterior compartment syndrome of the thigh resulting from blunt contusion without an accompanying fracture is rare. The treatment advocated for it by most authors has been surgical. However, because wound infection rates are high and loss of knee range of motion is frequent, we considered conservative treatment in selected patients. Six athletes who developed an anterior thigh compartment syndrome shortly after sustaining a blunt contusion to the quadriceps with an accompanying massive hematoma were studied prospectively. Tissue pressure, renal function, and creatinine phosphokinase (CPK) levels were closely monitored. Fasciotomy was not performed, despite sustained pressure elevations above 50 mm Hg. Neurologic function was not affected. At follow-up examination 1 year later, no limitation of joint motion nor weakness of the quadriceps were observed. Thus in selected young patients in whom an isolated anterior compartment syndrome of the thigh occurs, conservative treatment yielded results superior to fasciotomy.

Adult↗
PubMed1992

Devascularization of the anterior cruciate ligament by synovial stripping in rabbits. An experimental model.

In rabbits, synovial stripping of the anterior cruciate ligament was performed, and histologic and mechanical changes were followed up to 2 months. The operation did not immediately affect the strength of the ligament or its histological structure. However, a gradual deterioration of mechanical properties, associated with collagen necrosis and an ineffectual reparative response, was evident. Thus, synovial stripping of the ligament with the attendant concomitant devascularization leads to ligamentary insufficiency despite the lack of structural damage to the ligament by the contusion itself.

Animals↗
PubMed1991

Abductor pollicis longus tendon arthroplasty of the trapezio-metacarpal joint: surgical technique and results.

Tendon interposition resection arthroplasty of the trapezium is a valuable tool in treating osteoarthrosis of the first carpometacarpal joint. A previously unreported modification of such an operation is described in which a part of the abductor pollicis longus tendon is used as an interposition material. This technique was employed in a series of thirty-nine thumbs. After a minimal follow-up period of 2 years, the results of the operation are graded excellent in 48% of the patients, good in 35%, and average in the rest. Grip strength, as well as pinch strength, is about three quarters of the normal average. No patient needed a further operation.

Aged↗
PubMed1991

Active knee joint subluxation: its influence on the prognosis of ligament reconstruction.

Voluntary subluxation of the knee, known as active pivot shift, can be observed in a minority of patients with anterior cruciate ligament deficiency knees. We compared a group of 7 patients exhibiting voluntary subluxation of the knee joint with a group of 61 patients undergoing a similar operative procedure who did not demonstrate this sign. Despite similar age and similar operative procedures, the former group remained handicapped and regained the ability to subluxate the knee. We conclude that patients who exhibit voluntary subluxation of the knee joint are poor candidates for knee-ligament reconstruction.

Adult↗