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Biomedical subjects

M R Patel

Publications and source records attributed to M R Patel.

At least 73 records · Page 4Linked to original sources
PubMed1989

Enhancement of natural killer cell activity by Nocardia opaca fractions.

Three molecules derived from Nocardia opaca bacteria, NDCM, NWSMP, and PG, have been shown to express immunomodulating properties. The present study was aimed at assessing the effects of these derivatives on natural killer (NK) activity. Two experimental protocols were adopted, consisting of incubating whole or Percoll fractionated NK cells in vitro with those substances, and the other in which the derivatives were administered in vivo to mice and the activity assessed later. Incubation of spleen cells in vitro with NWSMP or its precursor NDCM promoted NK activity. This effect could be observed after only 2 h of incubation and continued until day 2. Percoll fractions 1-3, which contain most of the NK activity, were enhanced to a similar extent. Band 4, which is usually devoid of such activity, remained unresponsive even after contact with the N. opaca derivatives. PG was practically ineffective upon all the subsets. The results of experiments in vivo correlated with those obtained in vitro in that NWSMP and NDCM, but not PG, promoted NK activity. Bands 1-3 were similarly enhanced, the effect was observed after short treatment times, and could be partially cancelled by the concomitant administration of anti-interferon antibodies (anti-IFN Ab). All these findings suggest that the promoting effects of N. opaca derivatives are mediated through alpha/beta IFN. In contrast to the results observed on spleen NK cells, NK cells from the peritoneum displayed susceptibility mainly to PG, and much less to NWSMP or NDCM. The administration of PG to mice in vivo had a particularly marked promoting effect upon the cytotoxic activity of peritoneal cells. One logical explanation for the difference observed between PG and NWSMP or NDCM may be related to the specific IFN inducing properties of these compounds as well as to the different responsiveness of the NK cells present in the spleen and peritoneal cavity.

Animals↗
PubMed1988

Anomalous muscles of the first dorsal compartment of the wrist.

Exertion-induced pain and swelling in the distal forearm and radial aspect of the wrist were seen in two patients. Exploration revealed an anomalous muscle belly extending into the first dorsal compartment in both cases--an anomaly that we believe has not been previously reported. Surgical release of the compartment resulted in complete relief of pain in both patients.

Adult↗
PubMed1988

Patellar metastases. A case report and review of the literature.

A case of metastasis to the patella from adenocarcinoma of the lung is reported. The clinical presentation was similar to septic arthritis of the knee. Histopathologic examination established the metastatic nature of the lesion; this is the first case in which a patellar lesion was the only evidence of distant metastasis. Metastatic tumors of the patella are rare. Three cases of metastasis to the patella have been described from squamous cell carcinoma of the lung in the English literature. We report the first case of patellar metastasis from adenocarcinoma of the lung.

Adenocarcinoma↗
PubMed1988

Unfractionated spleen cells but not natural killer (NK) cells from RFM donors prevent the progression of host-versus-graft disease in murine RFM/(T6 x RFM)F1 chimeras.

Host-versus-graft (HVG) syndrome is the fatal allogenic disease which develops in susceptible strains of inbred mice following their perinatal inoculation with related F1 hybrid spleen cells. Deaths are caused by pathogenic immune complexes. It is thought that the antibody components of these complexes are produced by F1 donor B cells stimulated by the allogenic HVG reaction. To complement previous work that showed that lethal disease could be prevented if the HVG response was suppressed, the present studies tested whether or not it could also be prevented by augmenting HVG reactivity with the adoptive transfer of spleen cells syngenic with the host. The data show that unfractionated RFM spleen cells given on Days 13-14 prevented lethal disease in 86% of RFM/(T6 x RFM)F1 chimeras. Successful therapy was associated with the suppression of formation of nephropathic-immune complexes, and with the rejection of F1 donor cells or their gradual replacement by host cells. RFM spleen cells enriched for NK activity by a new improved method not only failed to prevent HVG disease but appeared to exacerbate it. This was also true of spleen cells that had been activated in vitro for 3 days with IL-2, a procedure that greatly enhanced their cytolytic activity against YAC-1 targets. It is suggested that therapy with NK cells failed, even after IL-2 activation, because they had no effect on proliferating and antibody-forming F1 donor cells that had engrafted in large numbers in the lymph nodes of the RFM hosts.

Animals↗
PubMed1987

Management of skeletal giant cell tumors of the phalanges of the hand.

Five cases of unicentric benign giant cell tumors of the phalanges of the hand are reported. Three patients were initially treated with curettage and bone grafting; two had recurrences that necessitated ray resection as the definitive treatment, and one was free of disease at 16 years' follow-up. The two patients who were primarily treated with ray resection were free of disease at follow-up of 2 and 1 years, respectively. Enneking's surgical staging system and Lodwick's x-ray grading of bone tumors were used to evaluate management methods.

Adolescent↗
PubMed1987

Osteochondritis dissecans of the patella.

We reviewed 13 cases of osteochondritis dissecans of the patella followed-up for 18 months to 19 years. Two were treated conservatively with excellent results, and 11 by operation with six excellent, four good and one fair result. There was complete radiographic healing of the defect in 10 cases and partial healing in three. The size of the osteochondritic lesion appeared to be of prognostic significance. Osteochondritis dissecans of the patella is the result of repeated minor injuries to the articular surface. Operation is indicated for persistent pain, intra-articular loose bodies and subchondral sclerosis; excision of the fragment and curettage of the crater, with or without drilling, is recommended.

Adolescent↗
PubMed1986

Suppression of cytolytic T-cell activity by staphylococcal enterotoxin B-induced suppressor cells: role of interleukin 2.

We have previously shown that staphylococcal enterotoxin B (SEB) is a potent inducer of suppressor T cells which function to inhibit antibody production in vitro. In the present paper we extend these studies and show that the SEB-induced suppressor cells also inhibit the development of cytotoxic lymphocytes in mixed-lymphocyte reaction (MLR) cultures. Since further analysis also showed that the level of interleukin 2 (IL-2) in cultures of SEB-primed cells was significantly reduced, experiments were carried out to determine the role of IL-2 in the inhibition of cytotoxic cell activity. Attempts to neutralize the suppression by supplementing MLR cocultures with delectinated supernatants from concanavalin A (Con A)-stimulated rat splenocytes were not successful. In addition, MLR cocultures supplemented on Day 0 with 50 units of affinity-purified IL-2 were also suppressed. Further analysis showed that the IL-2 activity in the supplemented MLR cocultures containing suppressor cells were significantly reduced by Day 3. However, repeated supplementation of the MLR cocultures with exogenous IL-2 was successful in achieving (and maintaining) "normal" levels of IL-2. The cytotoxic cell activity in these MLR cocultures remained suppressed. These results suggest that the inhibition of cytotoxic cell activity by SEB-induced suppressor cells is independent of IL-2 levels in the MLR coculture.

Animals↗
PubMed1986

Functional limb salvage with multimodality treatment in epithelioid sarcoma of the hand: a report of two cases.

Two cases of epithelioid sarcoma in the hand are reported. The first presented as a space-occupying lesion causing carpal tunnel syndrome, which has not been previously reported. The second case presented with a tumor in the palm that was initially misdiagnosed as a benign tumor and was treated inadequately and recurred. With treatment consisting of surgical excision, adjuvant local radiotherapy, and pulsed systemic chemotherapy combined with early detection and aggressive treatment of distant metastases, both patients have functional hands without local recurrence. They are presently free of obvious disease and remain under close observation at short follow-up of 6 and 4 years, respectively.

Adult↗
PubMed1986

Conservative treatment of mallet thumb.

Four cases of mallet thumb were treated conservatively by splinting the interphalangeal joint of the thumb in extension using the Stack splint. Two patients had sharply cut the extensor tendon on the dorsum of the proximal phalanx and two had avulsion of the extensor tendon from the base of the distal phalanx. Eight weeks of continuous splinting was followed by 2 weeks of night splinting. Six months of follow-up revealed excellent range of motion in all four cases.

Adolescent↗
PubMed1986

Pseudomalignant osseous tumor of soft tissue: a case report and review of the literature.

Pseudomalignant osseous tumor of soft tissues is a rare tumor of the hand. Histopathologic differentiation of this benign lesion from malignant lesions is difficult because mitotic figures are common in typical cases, but bizarre pleomorphic and hyperchromatic nuclei never occur. Wide excision is adequate in most cases, but ray resection is indicated when this benign lesion recurs after wide excision, invades the vital structures, or causes severe functional impairment. Review of the literature revealed 15 cases of this lesion in the digits of the hand, including our case. Of these 15 cases, misdiagnosis of malignancy in three cases and loss of function in an additional four cases led to ray resection.

Adult↗
PubMed1986

Stress fracture of the ulnar diaphysis: review of the literature and report of a case.

A 22-year-old athlete developed chronic pain in the forearm aggravated by weight lifting. Physical examination revealed localized tenderness at the junction of the middle and distal third of the ulnar diaphysis. X-ray films revealed an osteolytic lesion at the same level. The patient developed an overt fracture at the same site when he failed to stop sports activities against advice. The fracture healed uneventfully with immobilization in a sleeve cast.

Adult↗
PubMed1986

Conservative management of chronic mallet finger.

Ten cases of chronic mallet fingers that were 4 to 18 weeks old were treated conservatively by immobilization of the distal interphalangeal joint in extension for 8 continuous weeks and for 2 more weeks at night. With a stringent rating system, there were five excellent, four good, and one fair end result. Two patients had recurrence of the deformity within a week after treatment, and both fully recovered after 8 weeks of further splinting. Splinting is a predictable, safe, and simple method of treatment for chronic mallet fingers.

Adolescent↗
PubMed1986

Median nerve neuralgia caused by a fibrovascular band in the distal forearm.

A 67-year-old woman had experienced exquisite focal pain and tenderness for more than 1 year in the distal forearm 4.5 cm proximal to the distal wrist crease. Surgical exploration showed a venous fibrovascular band adherent to and transversing the epineurium of the median nerve precisely at the point of maximal tenderness. Resection of the fibrovascular band completely relieved the symptoms of focal pain and tenderness.

Aged↗