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Biomedical subjects

B J Masterson

Publications and source records attributed to B J Masterson.

17 recordsLinked to original sources
PubMed1992

Presence of epidermal growth factor, platelet-derived growth factor, and their receptors in human myometrial tissue and smooth muscle cells: their action in smooth muscle cells in vitro.

Immunohistochemical observations indicate that human myometrial smooth muscle cells express epidermal growth factor (EGF) and platelet-derived growth factor (PDGF)-AB and contain EGF and PDGF-beta receptors with no variation in intensity with phases of the menstrual cycle. Furthermore, immunofluorescent microscopic studies revealed that primary myometrial smooth muscle cell cultures also express EGF, PDGF-AB, and contain EGF and PDGF-beta, but not alpha-receptor. Incubation of subconfluent smooth muscle cells in serum-free medium leads to quiescence within 48 h as demonstrated by 3H-thymidine incorporation and labeling index. Exposure of quiescent cells to 10% fetal bovine serum stimulates resumption of DNA synthesis and proliferation in a time-dependent manner with a doubling time of 41.6 h. EGF (1.5-50 ng/ml) and PDGF-AB (1-10 ng/ml) in a dose- and time-dependent manner significantly stimulated 3H-thymidine incorporation by quiescent myometrial smooth muscle cells (P less than 0.05). Combinations of EGF (15 ng/ml) and PDGF-AB (10 ng/ml) significantly increased 3H-thymidine incorporation induced by either growth factor alone (P less than 0.05). PDGF-BB at 10 ng/ml also stimulated 3H-thymidine incorporation and its effect was similar to that induced by PDGF-AB at the same concentration. 17 beta-Estradiol (E2) at 1 microM inhibited 3H-thymidine incorporation by the smooth muscle cells (P less than 0.05). E2 also reduced the stimulatory effect of EGF (15 ng/ml) and PDGF (3 ng/ml). Progesterone at 1 microM either alone or in combination with E2 did not have any effect on 3H-thymidine incorporation or alter the mitogenic action of EGF and PDGF. The effect of EGF and PDGF on cell growth and 3H-thymidine incorporation by myometrial smooth muscle cells was independent of phases of the menstrual cycle. In summary, the results of present studies indicate that human myometrial tissue and myometrial smooth muscle cells in primary culture locally produce EGF and PDGF-AB and contain EGF and PDGF-beta, but not alpha-receptors. Moreover, the myometrial smooth muscle cells in culture respond to the mitogenic action of EGF and PDGF.

Autoradiography↗
PubMed1992

Platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and EGF and PDGF beta-receptors in human endometrial tissue: localization and in vitro action.

Human endometrial tissue and primary stromal cell culture contain immunoreactive epidermal growth factor (EGF), platelet-derived growth factor (PDGF)-AB as well as EGF and PDGF-beta receptors. The immunostaining for EGF, EGF receptor, and PDGF beta-receptor were associated with endometrial luminal and glandular epithelial and stromal cells, whereas only the stromal cells contain immunoreactive PDGF-AB. The immunostaining intensity of EGF, EGF receptor, and PDGF-AB was similar in both phases of the menstrual cycle, whereas, PDGF-beta receptor immunostaining was highest in proliferative phase and considerably reduced, particularly in luminal and glandular epithelial cells in the secretory phase. In addition primary stromal cell cultures express EGF, PDGF-AB, and contain EGF and PDGF-beta receptors, and very low levels of PDGF-alpha receptor. 3H-Thymidine incorporation indicate that after 48 h of incubation in serum-free medium approximately 75-80% of stromal cells are quiescent. Incubation of quiescent stromal cells with 10% fetal bovine serum stimulate 3H-thymidine incorporation in a time-dependent manner reaching maximal after 30-48 h, with a doubling time of 38.2 h. EGF (1.5-15 ng/ml) stimulates 3H-thymidine incorporation by quiescent stromal cells (P less than 0.001). This effect was significantly reduced at concentrations above 15 ng/ml (P less than 0.005). PDGF-AB (3-10 ng/ml) and PDGF-BB (0.5-10 ng/ml) also stimulate 3H-thymidine incorporation in quiescent stromal cells compared to controls (P less than 0.005). The action of EGF (15 ng/ml) and PDGF-AB (10 ng/ml) was time dependent, reaching maximal after 36 and 48 h of incubation (P less than 0.002). Addition of PDGF-AB (10 ng/ml) to EGF (15 ng/ml) significantly enhanced the action of EGF or PDGF-AB used individually (P less than 0.001). 17 beta-estradiol or progesterone at 1 microM did not stimulate 3H-thymidine incorporation, although they were stimulatory in combination (P less than 0.001), they did not alter the action of EGF or PDGF when added in combination. These observations provide further evidence that human endometrial tissue contains specific immunoreactive EGF receptors. It also demonstrates the presence of immunoreactive EGF, PDGF-AB, and PDGF-beta receptors in endometrial tissue as well as stromal cells in primary culture. Both EGF and PDGF are mitogenic for endometrial stromal cells, suggesting an autocrine/paracrine role in modulation of endometrial cell growth and differentiation.

Cell Division↗
PubMed1991

Selection of incisions for gynecologic procedures.

Progress is being made in the employment of abdominal incisions. The use of mass closure has greatly decreased the incidence of disruption. The avoidance of subcutaneous sutures has likewise decreased the rate of wound infections, and modern aggressive management has lessened the time that patients must contend with incisional abscesses when they do occur. There will always be considerable discussion and debate on the choice of an abdominal incision. However, the primary consideration remains always to choose and construct a surgical incision large enough to operate through comfortably and effectively.

Abdomen↗
PubMed1990

Tissue reactivity and degradation patterns of absorbable vascular ligating clips implanted in peritoneum and rectus fascia.

Absorbable vascular ligating clips are finding increasing use in intraabdominal surgery. We report the results of a light and scanning electron microscope investigation of the tissue reactivity and clip degradation patterns of two such materials, Absolok (polydioxanone) and Lactomer (copolymer of glycolic and lactic acid), implanted in the fascia and peritoneum of rabbits for intervals of 2 to 70 days. Cellular response to the clips, defined as the number of inflammatory cells/10(4) microns 2, was maximum at day 4 postimplantation, then gradually declined as the duration of implantation increased. This pattern, seen with both types of clips, was similar to that seen with polydioxanone (PDS) suture, but significantly greater than that associated with polypropylene (Prolene) suture. Although cellular response to the clips was greater in peritoneum than in fascia, especially on two occasions associated with adhesion formation, this was not statistically significant. Based on our morphological observations, the signs of clip degradation which were indicated by the appearance of surface crazing and cracks occurred earlier in peritoneum than in fascia.

Abdomen↗
PubMed1990

Stress relaxation of organic suture materials.

Sutures fabricated from synthetic polymeric materials exhibit the phenomenon of stress relaxation, that is, when held under tension at a fixed elongation, there is a gradual realignment of the microstructure to accommodate the developed tensile stress. This property has been characterized for three modern suture materials, polypropylene, polydioxanone and poly(glycolic acid). All three materials exhibited stress relaxation but to different degrees, with polypropylene exhibiting the greatest stress relaxation (to approximately 40% of the initial load). The initial rate of stress relaxation increased with the rate of loading but the residual stress level was found to be independent of elongation rate except at extremely low rates of loading.

Biocompatible Materials↗
PubMed1990

In vivo and in vitro degradation of monofilament absorbable sutures, PDS and Maxon.

Two new absorbable monofilament suture materials polydioxanone and Maxon are being employed increasingly in abdominal surgery because of increased strength retention and decreased tissue reactivity compared with previously available materials. As part of our investigation of the behaviour of suture materials, 3-0 sutures of polydioxanone and Maxon were enclosed in nylon pouches, a technique developed for in vivo experiments to prevent cellular interaction with implanted devices. The pouched sutures were gas sterilized, then implanted in either the extrafascial space or peritoneal cavity for periods of 1-5 wk. Sterilized sutures were also incubated in Ringer's lactate at 37 degrees C. Tensile strength of the exposed sutures was measured. For a given suture material and duration of incubation, there was no significant difference in tensile strength degradation among the three test environments. Although the strength of unexposed Maxon is greater than that of polydioxanone, the residual strength of Maxon decreases more rapidly in use, so that, after 2 wk, the strength of polydioxanone is greater. Scanning electron microscope examination of the suture surfaces reveals that polydioxanone develops surface crazing with time, whereas the surface morphology of Maxon remains relatively unaltered.

Animals↗
PubMed1990

Chromic gut pelviscopic loop ligature. Effect of the number of pulls on the tensile strength.

The failure load of a pelviscopic loop ligature (PLL) was determined after tightening the slip knot with one, two or three pulls. The PLL showed a significant decrease in strength when tightened with three or more pulls. In each group some PLLs failed from slippage rather than from fracture of the suture material at the base of the knot. Slippage occurred more frequently with each additional pull. The findings indicate that the surgeon should apply only one pull on the device for the most secure knot. In addition, there was no strength difference between the suture material itself and the junction of the suture and its plastic tail grip. The plastic tail grip of the PLL will not release the tail end of the suture material before either the suture material or the slip knot fails.

Catgut↗
PubMed1979

Extraspinal ependymomas. Report of three cases.

Spinal ependymomas may rarely arise from heterotopic ependymal cell clusters and thus occur in an extraspinal location. Presentation of three cases and a review of the literature reveal that these tumors have characteristic radiographic and clinical features. They occur mainly in patients in the third decade of life, and present either in the soft tissue posterior to the sacrum or in the pelvis. In the case of posterior tumors, the patient exhibits a mass which is usually mistaken for a pilonidal cyst. Patients whose tumor is pelvic in location present with sphincter disturbances or dysfunction of the sacral nerve roots. Conventional and computerized tomographic studies will reveal erosion of the sacrum. Myelography will demonstrate an extradural mass indenting the thecal sac from below. The protein in the cerebrospinal fluid will be normal. A combined posterior and anterior approach with the goal of complete tumor removal is the procedure of choice. If this is not feasible, then radiation therapy should be employed. Because of the increased incidence of systemic metastases, the average postoperative survival is approximately 10 years.

Adolescent↗
PubMed1978

Treatment of cervical intraepithelial neoplasia with the carbon dioxide laser beam. A preliminary report.

Forty-five patients with histologically proved cervical dysplasia or carcinoma in situ were treated by the carbon dioxide-laser method. The carbon dioxide laser induces cell vaporization by causing intracellular steam combustion stimulated by the emission of a mixture of carbon dioxide, nitrogen, and helium. This method of treatment is easily performed in the outpatient clinic without anesthesia, is inexpensive, and is effective in the treatment of cervical intraepithelial neoplasia. The treatment allows preservation of the transformation zone, thus permitting future colposcopic visualization.

Adult↗
PubMed1977

Role of tumor immunity in ovarian cancer.

Antigens associated with ovarian cancer tissue have been identified by the use of heteroantisera. It has also been reported that lymphocytes from patients with ovarian cancer responded to phytohemagglutinin (PHA) and keyhole-limpet hemocyanin (KLH) but had failed to respond to autologous tumor extracts. In our series, pretreatment sera from 37 patients with stage III and IV ovarian cancer failed to react with ovarian cancer antigen preparations. After therapy, serum from only three patients was reactive: all three patients were treated by chemoimmunotherapy. Preliminary data from this clinical trial for treating stage III and IV ovarian cancer with chemotherapy, immunotherapy, or combined chemoimmunotherapy show that survival of patients treated by chemotherapy or immunotherapy corresponded to that of nonresponders to L-PAM therapy as described in another study. Interestingly, combined chemoimmunotherapy produced a survival curve depicting significant improvement, similar to that for the responders to L-PAM therapy reported in that study.

Antibodies, Neoplasm↗
PubMed1977

Giant uterine tumors: case report and review of the literature.

This is a case report of the management and surgical removal of a 65-lb uterine leiomyoma. This is the 56th reported case of a giant uterine tumor (25 lb or over) and the eighth such case reported in the last 35 years. The literature concerning these large tumors is reviewed, and a discussion of some of the important aspects of surgical management is presented.

Female↗