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Biomedical subjects

A Gross

Publications and source records attributed to A Gross.

At least 163 records · Page 9Linked to original sources
PubMed1988

Induction of macrophage motility by a T-cell line from Balb/c mice specific for Plasmodium berghei malaria.

A long-term antimalaria T-cell line (AMTL) expressing a helper phenotype (Thy 1.2+, Lyt 2.2-) was established from Plasmodium berghei-recovered Balb/c mice. The ability of this T-line to induce macrophage motility was measured in vivo and in vitro. Adoptive transfer of AMTL cells to normal Balb/c mice showed an increased delayed hypersensitivity response to the homologous antigen, i.e., parasitized erythrocytes (PE). In vitro, AMTL culture supernatant (AMTL-SUP) augmented chemotactic locomotion of macrophages derived from both normal and infected mice. However, the effect on normal macrophages was significantly higher. AMTL cells adoptively transferred to normal mice had no effect on parasitemia levels or mortality rate after subsequent infection with P. berghei. Partial characterization of the AMTL-SUP indicated the involvement of a protein of about 12,600 Daltons in the enhancement of chemotaxis. These findings suggest that the AMTL cells and chemoattractants produced by them can induce macrophage motility, and that the macrophage malfunction in Balb/c with P. berghei infection is not due to defects at the T-lymphocyte level.

Animals↗
PubMed1988

Distal femoral varus osteotomy for valgus deformity of the knee.

Twenty-four patients who had degenerative arthritis of the lateral compartment of the knee that was associated with a valgus deformity and a superolateral tilt of the joint line were treated by distal femoral varus osteotomy. A surgical technique that was designed to produce a horizontal joint line and a tibiofemoral angle of zero degrees is described. At an average length of follow-up of four years, twenty-two of twenty-four patients had a successful result as judged by our protocol for evaluation. One osteotomy had to be revised for failure of fixation, and one patient had a pulmonary embolism that had a satisfactory outcome after the administration of anticoagulants. One patient required manipulation of the knee at six months. The simple surgical technique that we used was effective in realigning the femoral with the tibial axis in patients who had a valgus deformity of the knee, a superolateral tilt of the joint line, and osteoarthritis of the lateral compartment.

Adult↗
PubMed1988

Supracondylar fractures of the femur adjacent to resurfacing and MacIntosh arthroplasties of the knee in patients with rheumatoid arthritis.

Twelve cases of supracondylar fracture of the femur in rheumatoid arthritis patients with previously implanted resurfacing or MacIntosh arthroplasty of the knee had long standing severe polyarticular rheumatoid arthritis (duration, ten to 41 years; mean 24.8 years). The fractures occurred following a long interval after implantation of the prosthesis (five to 204 months; mean, 92.3 months). Two fractures were treated by stable and two by unstable fixation; eight were treated nonoperatively. The fractures healed in a normal time with one exception, but the femur was shortened in ten cases (mean, 2.8 cm), and axially malaligned in nine. The ability to walk long distances decreased in eight cases and pain increased in seven; two prostheses were loosened and displaced. Because of the poor results of nonoperative management, internal fixation of these fractures is recommended in selected cases.

Adult↗
PubMed1988

Cytochemical demonstration of enzymatic activities of the parotid, submandibular, and sublingual glands of Praomys (Mastomys) Natalensis.

Histochemical techniques were applied to salivary glands removed from adult multimmate rodents (Praomys) of either sex to detect and localize the following enzymatic activities: acid and alkaline phosphatase, arylsulphatase, ali-esterases, beta-glucuronidase, N-acetyl-betaglucosaminidase, and L-leucyl-aminopeptidase. No reaction was observed for alkaline phosphatase and glucuronidase. The glands reacted differently to the other enzymatic activities. Alkaline phosphatase and glucosaminidase were present only in one glandular type whereas arysulphatase and esterases were present in all types although demonstrating a variable staining intensity in different glands. Sharp differences in some enzymatic activities of the submandibular and parotid glands were related to the sex of the animal.

Acid Phosphatase↗
PubMed1987

Relationship of a Mr 140 fibronectin receptor and other adhesion-related glycoproteins to tumor cell-cell interaction.

Primary melanocytes attach poorly to collagen type IV and laminin, in contrast to their firm attachment to collagen type I/III and fibronectin [Gilchrest et al., In vitro (Rockville), 21: 114-120, 1985]. We have now found that metastatic B16 melanoma cells attach well to collagen type IV, laminin, vitronectin, and fibronectin but show a selective defect in attachment and cell aggregation on native collagen type I. Both flattened and aggregated melanoma cells revealed the presence of a Mr 120,000 surface-iodinated species with affinity for a matrix containing the hexapeptide (glycylarginylglycylaspartylserylproline) which includes the fibronectin cell attachment sequence, but only flattened cells showed significant exposure of a Mr 140,000 iodinated component with affinity for a large cell attachment-promoting fibronectin polypeptide. Decrease of the Mr 140,000 fibronectin-binding external protein in the collagen-cultured melanoma cells was also associated with an inability to respond to the cell attachment activity of fibronectin, laminin, or vitronectin added to the collagen gels. Metabolic labeling with [3H]glucosamine and electrophoretic analysis showed that lack of attachment and cell aggregation was associated with an increase in high molecular weight wheat germ agglutinin-binding glycoconjugates and an increase in Mr 55,000 concanavalin A-binding glycoprotein species. Our data suggest that: (a) melanoma cell attachment requires the expression of the Mr 140,000 fibronectin receptor which appears to be down regulated in cells exposed to poorly adhesive substrates; (b) expression of the Mr 120,000 iodinated species with affinity for the fibronectin attachment sequence (arginylglycylaspartic acid) may be necessary but not sufficient for firm cell-substratum interactions; (c) increased tumor cell-cell interaction may involve a decreased attachment to substrate and the expression of different glycoproteins which may modulate cell-cell association.

Amino Acid Sequence↗
PubMed1987

Keller arthroplasty: a prospective review.

A prospective study of the Keller procedure for hallux valgus was carried out on 44 female patients (75 feet) with an average age of 66 years. The average follow-up was 31 months (range, 12-64 months). The operation was effective in improving symptoms (joint pain and bunion tenderness), cosmesis, function (footwear and level of activity) and in decreasing the deformity. The operation did not have an influence on metatarsal calluses. Cock-up deformity was common postoperatively but did not affect the results. The overall patient satisfaction rate was 77%.

Aged↗
PubMed1987

Mononuclear cell subpopulations and infiltrating lymphocytes in erythema dyschromicum perstans and vitiligo.

Erythema dyschromicum perstans (EDP) and vitiligo are two cutaneous pigmentary dermatoses of unknown etiology. In the present study, the leukocyte infiltrates in the affected skin of EDP and vitiligo patients were studied using the avidin-biotin (ABC) immunoperoxidase technique and monoclonal antibodies which recognise the following mononuclear cell subgroups: T-suppressor/cytotoxic (CD8-Leu-2), T-helper (CD4 = OKT4), T-suppressor + macrophages (Leu-15), Pan T (CD3 = Leu-4), macrophages (Leu-M3) and Langerhans cells (CD1 = Leu-6), and other cellular markers such as Ia antigens and the Interleukin-2 receptor (CD25 = TAC). The immunocytochemical analysis showed a selective accumulation of CD3+, CD8+, Leu-15-, T-cytotoxic cells in the epidermis of both EDP and early lesions of vitiligo. In addition, an increase in the number of epidermal Langerhans cells (CD1+) was observed in some cases of EDP and vitiligo. The CD4/CD8 ratios in affected and uninvolved skin for both disorders were not significantly different, although values lower than unity were only observed in the infiltrates of affected skin. Ia antigen positivity was observed in the dendritic cells of the dermis and epidermis, as well as in most of the lymphoid cells within the infiltrates for both diseases. Macrophages (Leu-M3) in EDP dermal infiltrates were generally found adjacent to extracellular melanin pigment. Lymphocytes expressing TAC (CD25) surface antigens were also present in the dermal infiltrates. These morphological observations suggest a possible immune cell participation in the dyschromia of such cutaneous disorders.

Adult↗
PubMed1986

Autism and the fragile X syndrome.

The fragile X chromosome is an important factor in inherited mental retardation in males. It has also been reported that infantile autism is associated with fragile X. Recently, an article reported an examination of a small sample of autistic children in whom the fragile X chromosome was not found. Its authors concluded that if an association between fragile X and autism exists, it is infrequent. In the present study of 144 autistic male subjects, 18 were found to have the fragile X chromosome, supporting other (epidemiological) findings that the association between fragile X and autism occurs relatively frequently.

Adolescent↗
PubMed1985

An evaluation of temporomandibular joint sounds.

The purpose of this study was to obtain authoritative opinion on the importance of joint noises. Experts in the areas of orthopedics, rheumatology, and arthritis were asked four questions to evaluate the importance of clicking and crepitus in joints other than the temporomandibular joint (TMJ). The general response of these experts indicated that clicking in the absence of other symptoms is not important, clicking in the presence of other symptoms may be important, crepitus in the absence of other symptoms may be important, and crepitus in the presence of other symptoms is important. Caution is advised in treating clicking when it is the only sign.

Diagnosis, Differential↗
PubMed1984

Cell-mediated immunity in rats injected with an antimalaria T-cell line.

The aim was to develop a pure T-cell line which would enable the study of some aspects of the cellular immunity of malaria-injected rodents. For this purpose a long-term proliferative antimalaria T-cell line (AMTL) was established. The line was developed from splenocytes of rats recovered from a Plasmodium berghei infection. After adoptive transfer of the AMTL, some protection was demonstrated either by a lower mortality rate after challenge with the parasite or by decreased parasitemia in the T-cell injected versus control groups. Specific delayed-type hypersensitivity (DTH) was elicited by the AMTL: normal rats injected with the AMTL showed a DTH reaction to malaria antigens similar to the response observed in convalescent animals. Specificity was demonstrated by a marked response of the AMTL injected rats compared to rats injected with a control line (anti-purified protein derivative of tuberculin).

Animals↗
PubMed1983

Enzymatic synthesis of S-adenosyl-L-methionine from L-methionine and ATP.

S-Adenosyl-L-methionine (SAM) has been synthesized on 7-mmol scale from L-methionine and ATP. The ATP was generated in situ from AMP, and the synthesis of SAM was catalyzed by the enzyme ATP:L-methionine S-adenosyltransferase (EC 2.5.1.6). Although substantial effort was required to obtain even small quantities of enzyme, it has good stability once isolated and immobilized. The SAM produced by this procedure contains 89% of the (-) diasterioisomer and 11% of the (+) diasterioisomer.

Adenosine Monophosphate↗
PubMed1983

A prevalence study of the clinical signs associated with mandibular dysfunction.

A prevalence study was made of the most common clinical signs of mandibular dysfunction in a sample population of 1,000 patients in a general dental practice. Palpable joint irregularities (joint sounds) were found in about a third of the sample. All other frequencies were relatively low. Females had consistently higher frequencies than males, although the differences were generally not significant. A methodology that was quantified for the first time in relation to muscle palpation was used. Results of this study would indicate that the prevalence of the major clinical signs of mandibular dysfunction in the population expected to be seen in a general dental practice is not high and, furthermore, that their occurrence in the absence of pain does not necessarily indicate a need for treatment.

Adolescent↗