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Biomedical subjects

G D Bos

Publications and source records attributed to G D Bos.

At least 19 recordsLinked to original sources
PubMed2001

Introital stenosis requiring pelvic resection and soft tissue reconstruction.

BACKGROUND: Introital stenosis from both bony and soft tissue contracture is an unusual clinical problem not well addressed in the literature. CASE: A woman with a history of pelvic irradiation at age 1 for malignancy presented with severe introital stenosis unresponsive to conservative topical and dilatational therapy. She ultimately required staged bony resection of her infantile pelvis and soft tissue reconstruction to reestablish her introital aperture to an adequate and functional size. CONCLUSION: Introital stenosis from childhood requires a different treatment because development of the pelvis may not have been normal, and bony narrowing may exist in conjunction with soft tissue contracture. A staged multispecialty approach is recommended to treat this interesting variant of introital stenosis.

Adolescent↗
PubMed2001

Clinicopathologic analysis of HER-2/neu immunoexpression among various histologic subtypes and grades of osteosarcoma.

Overexpression of the HER-2/neu oncogene appears to have prognostic significance in breast cancer. Recently, some have reported a relationship between increased immunohistochemical expression in osteosarcoma and poor clinical outcome. Despite limited data, a pilot trial of Herceptin, which targets the oncogene product, has been initiated for the therapy of some metastatic osteosarcomas (CCG-P9852). Archival formalin-fixed, paraffin-embedded tissue obtained from 41 patients diagnosed with osteosarcoma was examined immunohistochemically by 2 antibodies against the HER-2/neu oncogene product: CB-11 (monoclonal, 1/100) and Oncor (polyclonal, 1/200). All but one tumor (case of recurrent dedifferentiated parosteal osteosarcoma) represented primary tumor samples; when applicable, only prechemotherapy biopsies were analyzed. The study sample included the full spectrum of histologic subtypes and grades of osteosarcoma (25 conventional high grade; 3 telangiectatic; 1 small cell; 6 parosteal; 1 periosteal; and 5 low-grade intramedullary). A case of metastatic breast cancer with known overexpression of the HER-2/neu oncogene served as the positive control. Complete membranous positivity, considered prognostically significant in breast cancer, was not seen in any of our osteosarcoma cases. At least focal cytoplasmic positivity was documented in 40 (98%) tumors using the CB11 antibody and in 34 (83%) using the Oncor antibody. The intensity of the cytoplasmic staining (0, 1-3+) did not correlate with histologic subtype/grade, response to chemotherapy (<90% versus > or = 90% necrosis), metastasis, or survival. Immunohistochemical overexpression of the HER-2/neu oncogene, defined as complete membranous positivity, is not present in our series of osteosarcomas. Cytoplasmic positivity is observed in most osteosarcomas, irrespective of histologic subtype/grade, and is not associated with response to preoperative chemotherapy or disease progression.

Adolescent↗
PubMed2001

Cartilaginous extracellular matrix of failed massive osteoarticular allografts.

Osteoarticular defects present a reparative challenge to orthopaedic surgeons. Osteoarticular allografts provided a promising solution. Unfortunately, many of these allografts failed secondary to articular cartilage degeneration. To determine the role of the extracellular matrix in graft failure, the authors have characterized the proteoglycan content of cartilage from grafts that failed early (2-4 years) and grafts that failed late (approximately 8 years) and compared this with normal cartilage. Cartilage was removed from all specimens. Proteoglycans were extracted and characterized based on molecular size and reactivity with antibodies. Protein and proteoglycan contents of early and late failure grafts were significantly lower per gram of tissue than normal cartilage. Patterns of distribution of associated proteoglycans and dissociated proteoglycans differed between early and later failure grafts and both were different from normal cartilage. Early failure cartilage contained less keratan sulfate proteoglycan with a different distribution of molecular sizes. Chondroitin sulfate epitopes showed discordance between early failure and normal cartilage and concordance between normal and late failure cartilage. These data show distinct differences in proteoglycan content between failed graft and normal cartilage and also between cartilage from grafts that failed early and late. Proteoglycan content and glycosaminoglycan substitution were altered in all specimens. Maintenance of a more normal extracellular matrix will be required to preserve function in these grafts for longer periods.

Antibodies, Monoclonal↗
PubMed2001

Selective drug resistant human osteosarcoma cell lines.

Chemotherapy in combination with surgery has been shown to be effective for the control of osteosarcoma. Development of resistance to chemotherapeutic agents is a recurring clinical problem. To investigate this phenomena, human osteosarcoma cells, TE-85, were exposed to increasing doses of Taxol or Taxotere during a 9-month period. Highly resistant subclones (TE-85TXL; TE-85TXR, respectively) were developed. Chemosensitivities are presented for TE-85 cell line and these new lines to Taxol, Taxotere, doxorubicin, cisplatin, and topotecan. Drug concentrations that inhibited cell growth by 50% compared with untreated cells were determined. The TE-85TXL cells showed resistance greater than 1,000-fold to Taxol and Taxotere and 60-fold to doxorubicin. The TE-85TXR cells showed resistance greater than 1,000-fold to Taxol, 800-fold to Taxotere, and 90-fold to doxorubicin. There was little cross resistance to topotecan and enhanced sensitivity to cisplatin. The role of P-170 glycoprotein in Taxol and Taxotere resistance was explored. Coincubation with verapamil, to block the actions of P-170 glycoprotein, partly reversed resistance to Taxol, Taxotere, and doxorubicin in both cell lines. Anti-P-170 glycoprotein antibodies revealed positive staining in TE-85TXL and TE-85TXR cell lines. Flow cytometry revealed reduced accumulation of doxorubicin in resistant cells. These data indicate that a human osteosarcoma cell line will develop resistance to Taxol and Taxotere, which is mediated in part by the P-170 glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Is fine-needle aspiration biopsy a practical alternative to open biopsy for the primary diagnosis of sarcoma? Experience with 140 patients.

We reviewed the clinicopathologic features of 145 consecutive fine-needle aspiration biopsy (FNAB) specimens from 140 patients without a previous diagnosis of sarcoma. Among 138 adequate specimens, 42 bone sarcomas and 80 soft tissue sarcomas were recognized as sarcomas; histologic subtyping was easier in bone than in soft tissue sarcomas and in pediatric than in adult cases. There was no correlation in accuracy of subtyping in low- vs high-grade sarcomas. FNAB was most accurate for subtyping of skeletal osteosarcoma, pediatric small round cell bone/soft tissue sarcomas, synovial sarcoma, skeletal chondrosarcoma, and adult myxoid soft tissue sarcomas. Although almost always recognized as sarcoma, subtyping of adult pleomorphic soft tissue sarcomas generally was not possible but did not influence therapy; all were considered high-grade sarcomas for treatment purposes. There were 4 misinterpretations of subtype in soft tissue sarcomas; none resulted in a change in therapy. Cytogenetic analysis on aspirated material confirmed t(11;22) in 2 Ewing and t(X;18) in 3 synovial sarcomas. No procedure-related complications occurred. Among bone and soft tissue sarcomas, FNAB was sufficient for initiation of definitive therapy in 87% and 83% of patients, respectively. Most FNAB specimens from bone and soft tissue sarcomas are recognized easily as sarcoma, but subtyping seems more accurate in bone sarcomas. Although histologic subtyping of adult soft tissue sarcomas is often impossible, no influence on initial therapy is usually observed. In contrast, subtyping of pediatric sarcomas by FNAB seems highly accurate and is necessary for appropriate therapy.

Biopsy↗
PubMed2001

Calcifying tendinitis of the gluteus maximus.

A case of calcifying tendinitis of the insertion of the gluteus maximus tendon is presented. Plain-film roentgenograms showed amorphous calcific densities extending from the posterior border of the femur. Computed tomography showed cortical erosion associated with the calcified mass. The patient responded well to needle lavage and injection with local anesthesia and corticosteroids. Fifteen-month follow-up roentgenograms showed resolution of the calcification. Recognition of this entity may make a workup and a biopsy unnecessary.

Buttocks↗
PubMed2000

The value of fine-needle aspiration biopsy in the differential diagnosis of adult myxoid sarcoma.

BACKGROUND: The usefulness of fine-needle aspiration biopsy (FNAB) for the histologic subtyping of specific sarcomas still is somewhat controversial but is becoming increasingly popular in the U.S. METHODS: To determine the accuracy and usefulness of FNAB in the differential diagnosis of myxoid sarcoma, the authors retrospectively reviewed 18 FNAB specimens (16 primary tumors, 1 local recurrence, and 1 metastasis) in 18 patients. The study sample included myxoid/round cell liposarcoma in six patients, myxofibrosarcoma in six patients, myxoid chondrosarcoma in five patients, and myxoid leiomyosarcoma in one patient. RESULTS: All but one tumor were recognized correctly as malignant. With regard to primary tumors, a specific cytologic diagnosis was rendered in 13 of 16 patients (81%). Problematic areas included the diagnosis of high grade myxofibrosarcoma with minimal amounts of myxoid stroma, myxoid liposarcoma with a predominant round cell component, and the single case of myxoid leiomyosarcoma. CONCLUSIONS: FNAB represents a valuable diagnostic tool for the differential diagnosis of myxoid sarcoma, especially myxofibrosarcoma, low grade myxoid liposarcoma, and myxoid chondrosarcoma. Due to its prognostic and therapeutic significance, the presence of a predominant round cell component in myxoid liposarcoma should be documented adequately. Other sarcomas (e.g., leiomyosarcoma) rarely may exhibit a prominent myxoid stroma and therefore should be considered in the differential diagnosis of adult myxoid sarcoma.

Adult↗
PubMed2000

Management of metastatic disease of other bones.

Metastases to the scapula and distal sites on the upper and lower extremities are infrequent. Although these metastases tend to occur in patients with advanced disease, a distal metastasis is occasionally the sole metastatic location. Distal metastases do not pose an immediate threat to a patient's life; however, they may cause significant pain and disability. Appropriate management can considerably enhance function, quality of life, and, occasionally, survival. Seven cases of distal metastasis are presented in this article with discussion of operative and nonoperative approaches to management.

Aged↗
PubMed1999

Fine-needle aspiration biopsy of soft tissue sarcomas. A cytomorphologic analysis with emphasis on histologic subtyping, grading, and therapeutic significance.

Because therapy for sarcoma often incorporates histologic subtype, grade, stage, and anatomic location, establishing a specific histologic subtype often is essential. To evaluate the effectiveness of fine-needle aspiration biopsy (FNAB) in histologic subtyping of soft tissue sarcomas, we retrospectively reviewed 73 consecutive aspirates from 67 patients, none of whom had a previously established sarcoma diagnosis. Sarcoma cases were subgrouped according to predominant cytomorphologic features: pleomorphic cell, 19; small round cell, 18; spindle cell, 18; myxoid, 10; epithelioid/polygonal cell, 7; 1 case of well-differentiated liposarcoma was analyzed separately. Ancillary studies were used for 25 cases. Among adequate specimens, 61 tumors were recognized as sarcoma. A specific and accurate histologic subtype was determined in 34 cases. Ancillary studies were most useful for histologic subtyping of small round cell and spindle cell sarcomas. Myxoid sarcomas were subtyped easily based solely on histomorphologic features. Pleomorphic cell and epithelioid/polygonal cell sarcomas were recognized easily as malignant but difficult to subtype by FNAB. With the exception of small round cell sarcomas, histologic subtyping of a sarcoma usually did not directly influence therapy. With meticulous attention to clinicopathologic features and ancillary techniques, many sarcomas, especially small round cell, spindle cell, and myxoid types, may be subtyped successfully by FNAB, within limitations.

Adolescent↗
PubMed1991

Total knee arthroplasty at a Veterans Administration Medical Center.

Total knee arthroplasty (TKA) was evaluated in 256 consecutive knees in a Veterans Administration hospital. Patient satisfaction and the effect of intercurrent illness were studied in addition to standard clinical and roentgenographic parameters. Evaluation of results show the superiority of condylar knee designs. In general, TKA was successful with a high degree of patient satisfaction.

Adult↗
PubMed1988

Biopsy proven eradication of an aneurysmal bone cyst treated by superselective embolization: a case report.

A large aneurysmal bone cyst of the upper tibia in a 17-year-old patient was treated by superselective embolization with excellent clinical and radiological results. Extensive curettage and detailed pathologic analysis performed 2 years following embolization revealed only healing bone. The presented case and reviewed cases in the literature indicate that embolization is a promising method for definitive therapy of the aneurysmal bone cyst.

Adolescent↗
PubMed1988

Epithelioid sarcoma. An analysis of fifty-one cases.

Analysis of the cases of fifty-one consecutive patients who had an epithelioid sarcoma revealed the five-year rate of survival to be approximately 70 per cent and the ten-year rate, approximately 50 per cent. The five-year rate of survival was about 40 per cent for the male patients and about 80 per cent for the female patients. If the primary tumor was more than three centimeters in diameter or was deeply situated, the patients had a reduced life-span, as did the patients in whom the tumor was focally necrotic. More male than female patients had necrosis of the tumor, as seen on the pathological specimens. No significant difference in life-span was noted among the patients in whom the resection had a marginal, wide, or radical surgical margin. The data indicate that wide or radical resection should be done as soon as epithelioid sarcoma is diagnosed.

Adolescent↗
PubMed1987

Biology of cancellous bone grafts.

Despite 30 years of experimental bone grafting research, the fresh cancellous bone graft remains the most osteogenic and reliable bone grafting material. Recent experimental data suggest that modification of the graft-host interaction by antigen matching or immune manipulation may allow increasingly successful use of allografts.

Animals↗
PubMed1985

Bone grafting: role of histocompatibility in transplantation.

The role of histocompatibility matching in bone allografting was studied in two canine bone graft models. In a cancellous ulnar segmental replacement model, frozen bone allografts exchanged between closely matched dogs were significantly better incorporated by radiographic and histologic criteria than were strongly incompatible grafts. Frozen allografts from disparate donors in recipients receiving immunosuppression appeared indistinguishable 6 months later from those in the untreated closely matched groups and from fresh autografts. Fresh vascularized orthotopically placed fibular bone grafts were evaluated by quantitative blood flow assessment, microangiography, and fluorochrome histomorphometry. Revascularized grafts exchanged between untreated closely matched dogs demonstrated preservation of blood flow and a pattern of repair that was delayed but not otherwise different than vascularized autografts. These results suggest that fresh vascularized grafts in the judiciously matched or immunosuppressed recipient offer attractive clinical possibilities.

Animals↗
PubMed1984

Improved acceptance of frozen bone allografts in genetically mismatched dogs by immunosuppression.

UNLABELLED: We studied the role of immunosuppressive therapy in improving the incorporation of frozen bone allografts exchanged across strong transplantation barriers in a canine cancellous ulnar segmental replacement model. Dogs receiving frozen bone from donors with major histocompatibility differences received one of three different immunosuppressive treatments. In two groups, azathioprine and prednisolone were administered for either twenty-eight or fifty-six days; anti-lymphocyte globulin was added for another twenty-eight-day group in a third regimen. Frozen bone was evaluated radiographically and histologically by criteria that quantified the biological characteristics of the bone itself and union between the graft and host at thirteen and twenty-six weeks after grafting. Graft incorporation in these animals was compared with graft acceptance in a similar group of untreated animals and in untreated animals in which bone was exchanged across weak transplantation barriers. Complications of immunosuppression included wound drainage, infection, weight loss, and falling white-blood-cell counts. Seven of the original thirty-seven animals died as a direct result of these complications. After twenty-six weeks the grafts in the recipients receiving immunosuppression appeared radiographically and histologically indistinguishable from those in the untreated, genetically closely matched group and from autografts. They were significantly better incorporated than identical allografts placed in untreated, genetically disparate recipients. There was no difference in the effectiveness of any of the immunosuppressive programs. CLINICAL RELEVANCE: Immunosuppression improves the biological outcome of otherwise poorly performing frozen bone allografts in dogs. This finding suggests that treatments that modify the immunological response of the host without major side effects may be useful clinically in improving the success of massive frozen bone allografts.

Animals↗
PubMed1983

Mortality in an european cohort occupationally exposed to epichlorohydrin (ECH).

A study was undertaken on the mortality of workers exposed to ECH at four European sites with plants producing epichlorohydrin (ECH), epoxy resins, glycerin, and other specialty chemicals derived from ECH. The vital status of 606 individuals with at least one year of exposure to ECH, starting at least 10 years before the final date of the study on 31 December, 1978, were collected. Mortality was analysed for a subgroup with 10 or fewer years of exposure, and another subgroup with more than 10 years of exposure. Four deaths from different cancers were observed against five expected. No excess mortality from cancer was observed in either subgroup or the complete cohort, which could be related to ECH exposure. The small size of the cohort and the limited number of deaths due to low average age (42 years), as well as the short duration of the observation period, do not allow a firm conclusion to be reached regarding the potential carcinogenicity of ECH in man. Current exposure levels are low, but exposure in the early days of production occasionally reached levels high enough to be irritating. We recommend updating the study 5 years from the final date of the present study, i.e. on 31 December, 1983. Within their limitations this and other epidemiological studies so far provide no evidence for an association between occupational exposure to ECH and the occurrence of malignant neoplasms in man.

Chlorohydrins↗