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Biomedical subjects

B Howard

Publications and source records attributed to B Howard.

At least 19 recordsLinked to original sources

Congenital pseudarthrosis.

Five cases of congenital pseudarthrosis of the clavicle were treated with open reduction and fixation with appropriate-sized contoured plates and screws. Iliac bone grafts were used to bridge the gap in four patients; local bone graft was used in the fifth patient. Consolidation was noted an average of 3 months postoperatively in all five cases. The plate and screws were removed in all patients at an average of 16 months postoperatively. Average length of follow-up for the five patients is 4 years. Roentgenograms demonstrate that the clavicle has continued to grow normally. All five patients have pain-free full range of motion and are engaged in unrestricted activities.

Bone Plates

A patient with Werner's syndrome and osteosarcoma presenting as scleroderma.

Werner's syndrome (WS) is often mistaken for scleroderma. We describe a patient with WS who presented with an enlarging, painful mass of the right knee that proved to be a juxtaarticular osteosarcoma of the distal femur. Recognition of WS and prompt investigation of any painful, enlarging masses to exclude sarcomatous degeneration will benefit these patients.

Bone Neoplasms

Evaluation of the accuracy of the home ovulation detection kit, Clearplan, at predicting ovulation.

A home ovulation testing kit, Clearplan, that detects the urinary luteinizing hormone (LH) surge was compared with basal body temperature (BBT) charts and cervical scoring as a method of ovulation prediction in 54 consecutive patients. The accuracy of all these methods was evaluated using daily serum LH measurements. Clearplan was shown to be significantly more accurate at timing ovulation than were BBT charts (P less than 0.0001) and cervical scoring (P less than 0.025). In 82%-88% of cases the kit predicted ovulation within one day and in 89%-96% of cases within two days of the serum LH surge. The kits were found to be easy to use and their potential place in clinical practice is discussed; home ovulation testing may ultimately replace serum LH assays as the method of choice in timing ovulation.

Body Temperature

Bacteria-lectin interactions in phytohemagglutinin-induced bacterial overgrowth of the small intestine.

The mechanism of phytohemagglutinin-induced bacterial overgrowth of the small bowel in the rat was studied. Interaction of the lectin with bacterial isolates selected at random from those that comprised the major population of the overgrowth was determined. In both bacterial agglutination assays and glycocalyx stabilization, no specific association between lectin and bacteria was seen. In three independent binding assays phytohemagglutinin was not found to increase bacterial adherence to washed intestinal mucosa. Phytohemagglutinin would not appear to act, therefore, as a direct ligand to mediate bacterial adherence or to modify the mucosal surface to increase bacterial adherence.

Agglutination Tests

Spontaneous osteonecrosis of the tarsal navicular in adults: imaging findings.

We encountered five otherwise healthy adults with alterations of the tarsal navicular bone compatible with spontaneous osteonecrosis. Four women had bilateral involvement and one man had unilateral involvement. The patients were 23-71 years old. The disorder was initially described by Mueller and Weiss and should not be confused with Koehler disease (osteochondrosis of the tarsal navicular in children). This group of patients was compared with five other patients (29-74 years old) with similar radiographic and clinical changes in whom an underlying disease (rheumatoid arthritis, renal failure, trauma, and lupus erythematosus) associated with osteonecrosis was known. Routine radiography in both groups defined characteristic abnormalities of the navicular bone (decreased size, a comma-shaped configuration, increased radiodensity, fragmentation, and medial or medial and dorsal osseous protrusion). MR in three patients confirmed alterations consistent with osteonecrosis. Three of the patients without underlying disease had bilateral involvement on plain films, with flat feet and hindfoot valgus deformity, leading to local pain and deformity. In a fourth patient, bilateral distribution was documented by MR as marrow alterations. Although no certain pathogenic explanation for spontaneous osteonecrosis of the tarsal navicular is known, trauma and chronic stress changes caused by physiologic pressure on the medial longitudinal arch in hindfoot valgus and increased tension forces of the plantar aponeurosis during weight-bearing (in pes planus) may be important. Discrimination of primary from secondary osteonecrosis of the tarsal navicular bone is not possible by radiologic means alone, although bilateral distribution, particularly in women, favors the diagnosis of spontaneous disease.

Adult

Septic arthritis.

Infectious arthritis is a commonly encountered clinical problem which may result from articular contamination by a wide variety of organisms. Involvement of an articulation may occur by one of four mechanisms: hematogenous spread, spread from a contiguous source of infection, direct implantation, or postoperative contamination. Distribution is typically monoarticular with a swollen, erythematous, and painful joint. The radiographic differential diagnosis includes limited rheumatoid arthritis, gout, synovial osteochondromatosis, and pigmented villonodular synovitis. In order to prevent complications, including growth disturbances, articular destruction with ankylosis, osteomyelitis, or soft tissue extension, early diagnostic arthrocentesis is important. Radiographic abnormalities, which include soft tissue swelling, joint space loss, periarticular osteopenia, and central or marginal osseous erosions, may be delayed following clinical onset of infection. Advanced imaging techniques such as scintigraphy, CT, or MRI may allow accurate diagnosis of the infectious process at an earlier stage.

Arthritis, Infectious

Arthrography, tenography, and bursography of the ankle and foot.

A brief description of normal anatomy and common arthrographic, tenographic, and bursographic procedures is presented. The described procedures are important diagnostic tools and do not carry major risk. Therefore, these procedures can be performed on an outpatient basis.

Ankle

Primary rat embryo cells transformed by one or two oncogenes show different metastatic potentials.

Second-passage rat embryo cells were transfected with a neomycin resistance gene and the activated form of the c-Ha-ras I gene, or with these two genes plus the adenovirus type 2 E1a gene. Foci of morphologically transformed cells were observed in both cases; however, the frequency of transformation was at least ten times higher with two oncogenes than with the ras gene alone. All the transformed cell lines gave rise to rapidly growing tumors when injected subcutaneously into nude mice. All but one of the cell lines transformed by the ras oncogene alone formed metastatic nodules in the lungs of animals that had been injected subcutaneously with transformed cells. When transformed cells were injected intravenously, all the ras single-gene transformants gave rise to many metastatic lung nodules. In contrast, cell lines transformed with ras and E1a did not generate metastases after subcutaneous injection and gave rise to very few metastatic lung nodules after intravenous injection. These data demonstrate that a fully malignant cell with metastatic potential, as measured in an immunodeficient animal, can be obtained from early passage embryo cells by the transfection of the ras oncogene alone.

Animals

The 5'-flanking sequences of human globin genes contribute to tissue specific expression.

The specificity of expression of the isolated 5'-flanking sequences of the human beta- and epsilon-globin genes was examined in the K562 human erythroleukemia cell line, the murine erythroleukemia (MEL) cell, and in nonerythroid cell lines CV-1, HeLa-S3, and WI-38. Globin flanking sequences were active only in the erythroid K562 and MEL cell lines. Furthermore, the upstream sequence of the adult, beta-globin gene was active in MEL cells which express adult globin and not in K562 cells which express embryonic and fetal globins suggesting that tissue specificity resides in these upstream sequences. No expression was observed in K562 cells which have an embryonic-fetal hemoglobin phenotype.

Acetyltransferases