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Biomedical subjects

M J Merino

Publications and source records attributed to M J Merino.

At least 109 records · Page 6Linked to original sources
PubMed1992

Distribution of the 72-kd type IV collagenase in nonneoplastic and neoplastic thyroid tissue.

The 72-kd type IV collagenase (matrix metalloproteinase-2 [MMP-2]) is a neutral metalloproteinase that initiates the degradation of type IV collagen in basement membranes. Its production by tumor cells has been correlated with the invasive and metastatic potential of neoplasms. Two recently developed affinity-purified antibodies against synthetic peptides from the amino terminus (H1) and an internal domain (Ab48) of the molecule were used to investigate immunohistochemically the distribution of this enzyme in a variety of thyroid tissues. All primary carcinomas (20 papillary, seven follicular, and three medullary) as well as nine of 11 metastases were positive, with the more aggressive tumors (tall cell variant of papillary carcinomas and invasive follicular carcinomas) tending to be more reactive than the low-grade tumors (classic and microinvasive papillary carcinomas and minimally invasive follicular tumors). Negative or minimal positivity was found in six cases of normal thyroid, one goiter, and two cases of Graves' disease. Immunoreactive follicular cells were seen focally in areas of inflammation, fibrosis, and distortion of normal follicles, and in Hashimoto's thyroiditis (four cases). Five of nine adenomas showed positive cells, but this could be related to previous trauma to the area. We conclude that there is increased production of the 72-kd type IV collagenase (MMP-2) in thyroid cancer; however, this enzyme also is elevated in benign conditions that are undergoing remodeling and repair.

Adenocarcinoma↗
PubMed1992

A thyroid biopsy with histologic features of both Riedel's thyroiditis and the fibrosing variant of Hashimoto's thyroiditis.

We describe a 36-year-old woman with clinical, laboratory, and histologic features of both Riedel's thyroiditis and the fibrosing variant of Hashimoto's thyroiditis. Features of the former included a hard, fixed thyroid mass and extensive involvement of perithyroidal tissues by dense fibrosis with lymphocytes, histiocytes, and plasma cells. Features supporting Hashimoto's thyroiditis included high serum titers of antimicrosomal and antithyroglobulin antibodies and the histologic findings within the thyroid gland itself: dense fibrous bands dividing the thyroid parenchyma into nodules composed of lymphoid follicles with germinal centers, plasma cells, and oxyphilic metaplasia of follicular epithelial cells. Although Riedel's thyroiditis and the fibrosing variant of Hashimoto's thyroiditis were once considered morphologic variants of the same disease, since the 1970s these diseases have been considered as distinct clinicopathologic entities. The coexistence of both diseases in a patient is rare and is probably coincidental in this instance.

Adult↗
PubMed1992

Low-grade angiosarcoma of the skin of the breast: a complication of lumpectomy and radiation therapy for breast carcinoma.

A case of low-grade angiosarcoma arising in the skin of a breast previously irradiated for breast carcinoma is reported. Initially, an asymptomatic breast mass was detected. Excisional biopsy and axillary lymph node dissection revealed a 1.5-cm infiltrating ductal carcinoma with 21 negative lymph nodes. The neoplasm was staged as T1, N0, M0. The patient was entered in a research protocol and was treated with high-dose external beam (4,860 rad) and iridium implant (1,860 rad) irradiation. Seven years later the patient developed low-grade angiosarcoma of the breast skin. The lesion recurred following excision and eventually was treated by simple mastectomy. The patient never had evidence of lymphedema. Cutaneous angiosarcomas occurring as a complication of lumpectomy and radiation therapy for breast carcinoma are rare. In some reported cases the patients have had lymphedema, a known factor predisposing to angiosarcoma. Furthermore, almost all cases previously reported have been high grade. This case suggests that radiation therapy for breast carcinoma may also be complicated by low-grade angiosarcoma.

Breast↗
PubMed1992

Delayed endometrial maturation induced by daily administration of the antiprogestin RU 486: a potential new contraceptive strategy.

OBJECTIVE: Our objective was to determine if a progesterone antagonist might interdict the development of a secretory endometrium. STUDY DESIGN: Eleven normally cycling women not at risk for pregnancy received RU 486 (1 mg/day orally) or placebo throughout one menstrual cycle in a randomized, double-blind, crossover fashion. Estradiol, progesterone, and placental protein 14 were measured every 3 days; luteinizing hormone was measured until the midcycle surge was detected. An endometrial biopsy was performed on luteal phase day 7 to 9 and interpreted with Noyes' criteria. Differences between treatment groups were analyzed by the Student t test. RESULTS: RU 486 delayed ovulation, retarded endometrial maturation, and reduced peak levels of placental protein 14 without affecting gonadal steroid production. The abnormalities in endometrial morphology and function are similar to those seen in infertile women with luteal phase defects. CONCLUSION: We hypothesize that this regimen of antiprogestin administration may prevent implantation and offer a novel strategy for fertility control.

Adult↗
PubMed1992

Immunotherapy with interleukin-2 and alpha-interferon in patients with metastatic renal cell cancer with in situ primary cancers: a pilot study.

A total of 12 patients with stage 4 renal cell carcinoma and primary renal tumors in situ was entered into a pilot study using treatment with interleukin-2 and alpha-interferon followed by radical nephrectomy. Of the patients 11 underwent nephrectomy after an initial course of immunotherapy. Ten patients were able to receive a second course of immunotherapy given after nephrectomy. One patient achieved a complete response of lung and mediastinal metastases without any change in the primary renal tumor but after nephrectomy the patient remained in complete remission for greater than 11 months. A total of 3 patients achieved a partial response at some extrarenal sites but they had progression elsewhere. Toxicity was similar to previous experience with this immunotherapy regimen. Therefore, we demonstrated that metastatic tumor regression is possible with primary renal tumors in situ and that aggressive interleukin-2-based immunotherapy can be tolerated in the presence of a large renal tumor.

Adult↗
PubMed1992

Successful treatment of systemic Exophiala dermatitidis infection in a patient with chronic granulomatous disease.

Exophiala dermatitidis, one of the saprophytic dematiaceous fungi, is a rare cause of human infection that, when invasive, is nearly always fatal. Besides the more common subcutaneous infection usually caused by traumatic inoculation, infection can also spread hematogenously, in which case the organism has a distinct neurotropism. A patient with autosomal recessive chronic granulomatous disease of childhood who was found to have a progressive pulmonary and central nervous system infection with E. dermatitidis responded to an aggressive, multifaceted therapeutic approach. Scanning electron microscopy of the cultured conidiogenous cells confirmed that the manner of conidiogenesis is typical of the genus Exophiala. We report the first successful treatment of an infection involving the lungs and central nervous system by a combination of surgical resection of the pulmonary source and medical therapy with amphotericin B, flucytosine or ketoconazole, and transfused white cells, followed by a prolonged course of fluconazole.

Adult↗
PubMed1992

Evaluation of basement membrane components and the 72 kDa type IV collagenase in serous tumors of the ovary.

We studied the distribution of the basement membrane components laminin and type IV collagen in 46 serous tumors of the ovary, including a group of low malignant potential tumors with microinvasion. The findings were correlated with the expression of the 72 kDa type IV collagenase, an enzyme that initiates the degradation of type IV collagen and consequently may play a role in the process of invasion. Benign cystadenomas and tumors of low malignant potential without microinvasion showed a continuous basement membrane; whereas invasive carcinomas, peritoneal implants, and lymph node metastasis had frequent disruptions and extensive areas without basement membrane components. Early invasion in tumors of low malignant potential was characterized by focal disruptions in basement membranes and complete absence of laminin and type IV collagen around single or clusters of microinvasive cells. Type IV collagenase was negative or minimally expressed in cystadenomas, whereas in invasive carcinomas and metastasis the reactivity was moderate to intense. Microinvasive cells in tumors of low malignant potential were strongly positive. The collagenase IV was also localized in cell clusters elsewhere in the tumors where the basement membrane was still preserved. These cells had a similar morphology to that of the microinvasive cells. We conclude that detection of basement membrane components may be useful in recognizing early invasion in this group of ovarian neoplasms. The correlation between progressive anomalies of the basement membrane and expression of type IV collagenase suggests that this enzyme functions directly in the degradation of basement membrane components and facilitates the invasive process.

Basement Membrane↗
PubMed1992

Role of tumor necrosis factor in oxygen toxicity.

mRNA from lungs of mice exposed to high-dose oxygen (greater than 95%) for 3 days demonstrated increased expression of the genes for tumor necrosis factor (TNF), interleukin-1, and interleukin-6 compared with mRNA from lungs of mice exposed to room air. Daily treatment of mice exposed to high-dose oxygen with an antibody to TNF improved survival compared with mice receiving a similar dose of control immunoglobulin G. Pretreatment of mice with repetitive sublethal intraperitoneal doses of recombinant human TNF for 3 days or a single intravenous dose followed by exposure to high-dose oxygen afforded a significant survival advantage compared with high-dose oxygen-exposed mice pretreated with vehicle or interleukin-1. The repetitive intraperitoneal TNF pretreatment reduced the development of interstitial pneumonitis, pulmonary edema, and lung weight gain associated with oxygen toxicity and enhanced expression of the gene for the free radical protective enzyme manganous superoxide dismutase in lung tissue, a gene that is augmented as mice are exposed to high-dose oxygen. Furthermore a single intravenous dose of TNF 24 h after oxygen exposure was still protective. The results suggest that the toxicity of oxygen therapy can be partially ameliorated by either treatment with anti-TNF antibody or pretreatment and early treatment with TNF. These findings are consistent with the hypothesis that oxygen exposure induces TNF, which causes part of the toxicity of high-dose oxygen, and that pretreatment or early treatment with TNF induces the gene for an enzyme that recently has been shown to be very effective in protecting mice from the toxicity of oxygen.

Animals↗
PubMed1992

Patterns of basement membrane laminin distribution in nonneoplastic and neoplastic thyroid tissue.

Laminin, a major basement membrane component, is typically absent or partially lost around the epithelial elements of most invasive carcinomas. To evaluate the distribution of laminin in both primary and metastatic thyroid tumors, we studied 14 benign thyroid lesions (eight adenomas, two Graves' disease, two Hashimoto's thyroiditis, one adenomatous hyperplasia, one nodular goiter), 20 carcinomas (seven papillary, six tall cell variant, four follicular, three Hürthle), and eight metastases (five tall cell variant, three follicular) utilizing a polyclonal antibody against highly purified, nidogen-free laminin. All benign lesions showed positive, linear immunostaining along basement membranes. Partial loss or absence of laminin was seen in the solid areas of all types of thyroid carcinomas examined; well-differentiated papillary and follicular tumors, as well as papillary and follicular areas of more poorly differentiated neoplasms, maintained linear laminin immunostaining in the papillary cores beneath the epithelial cells and around follicles. A similar correlation between laminin deposition and architectural organization was seen in metastatic lesions. Hürthle cell carcinomas had a unique fragmented, pericellular immunostaining pattern around individual tumor cells, suggesting uncontrolled laminin synthesis. Our findings suggest that preservation of laminin production in thyroid tumors reflects their degree of differentiation and that absence of laminin correlates with lack of structural organization rather than reflecting invasive and metastatic potential.

Basement Membrane↗
PubMed1992

Immunohistochemical profile of basement membrane proteins and 72 kilodalton type IV collagenase in the implantation placental site. An integrated view.

An immunohistochemical study was performed to investigate the interactions between trophoblast and the extracellular matrix in the implantation site of early pregnancies. Two basement membrane-related proteins (type IV collagen and laminin), as well as the expression of the 72 kilodalton type IV collagenase, were studied with affinity-purified antibodies. human placental lactogen, human chorionic gonadotropins, and AE1/AE3 cytokeratins were used to identify the different cell populations involved in the implantation process. All types of trophoblastic cells, from villous cells to the different types of intermediate trophoblast, expressed the 72 kilodalton type IV collagenase. Decidual cells, Hofbauer's cells, villous fibroblasts, and amnion were also positive. Laminin and type IV collagen were expressed in all basement membranes, including large decidual and intermediate trophoblast cells, and the villous stroma. Nitabuch's layer, an acellular degradative zone at the site of initial attachment, showed positivity for type IV collagen. The extracellular matrix in the implantation site seems to be a meshwork of, among other components, laminin and type IV collagen, in which the invading trophoblastic cells are embedded. The invasive capacity of these cells in vivo may be, at least in part, mediated by their type IV collagenolytic activity along with that of the decidual cells, thus regulating the permeability of the extracellular matrix.

Amino Acid Sequence↗
PubMed1992

Recombinant interleukin-1 receptor antagonist (IL-1ra): effective therapy against gram-negative sepsis in rats.

BACKGROUND: Morbidity and mortality from bacterial sepsis remain high despite aggressive diagnostic and therapeutic intervention. Interleukin-1 has been implicated as mediator of the lethal effects of endotoxemia or bacterial sepsis. The current experiments were designed to evaluate the therapeutic efficacy of a human recombinant interleukin-1 receptor antagonist (IL-1ra) against polymicrobial gram-negative septicemia in rats. METHODS: Male rats underwent placement of indwelling carotid arterial and superior vena caval catheters followed by cecal ligation and puncture (CLP). After 3 hours rats received either IL-1ra (10 mg/kg intravenous bolus followed by 5 mg/kg/hr) or an equal volume of vehicle intravenously for 24 hours. Heart rate, respirations, mean arterial blood pressure, and temperature were recorded at frequent intervals, and survival was assessed for 30 hours after CLP. RESULTS: There were no differences in vital signs between groups at baseline or before treatment, and all animals appeared ill with huddled posture, piloerection, and hyperventilation. Twenty-four hours after CLP, IL-1ra significantly ameliorated bradycardia (p = 0.01), hypothermia (p = 0.001), and hypotension (p = 0.05), and 30-hour survival was significantly improved (71% vs 20%, p less than 0.05). CONCLUSIONS: IL-1ra lessens the acute hemodynamic, hypothermic, and mortal effects of gram-negative sepsis induced by CLP in rats. These data suggest that IL-1 receptor blockade may be an important new treatment strategy against overwhelming bacterial sepsis.

Animals↗
PubMed1992

Pelvic radioiodine uptake in a rectal wall teratoma after thyroidectomy for papillary carcinoma.

A 30-yr-old woman with previously resected papillary thyroid carcinoma was found to have a pelvic lesion which concentrated radioiodine. By performing simultaneous 131I whole-body and 99mTc-methylene diphosphonate bone scans, we found the lesion to be in soft tissue between the sacrum and bladder. Radioiodine therapy was postponed so that the lesion, a benign teratoma of the rectal wall, could be surgically removed. Prior to laparotomy, the patient received a second tracer dose of 131I so that the lesion could be located at surgery with a hand-held gamma detector. A postoperative whole-body 131I scan confirmed that the lesion had been removed, thus reducing the absorbed radiation that would have been received by the ovaries during radioiodine therapy. Although the lesion contained both thyroid and gastric epithelium, accumulated 131I was limited to the area with thyroid follicles.

Adult↗
PubMed1992

A prospective study of the value of core needle biopsy and fine needle aspiration in the diagnosis of soft tissue masses.

We prospectively sampled 38 large soft tissue masses in 37 patients with both core needle biopsy (CNBX) and fine-needle aspiration (FNA) to determine the diagnostic utility of these biopsy methods. In 27 cases the histologic diagnosis made from the resected specimen was compared with the diagnosis based on the biopsy. CNBX correctly identified 16 of 16 malignant sarcomas and 10 of 11 benign masses (one was indeterminate). The grade of the sarcoma was determined correctly in every case. There were no false malignant or false benign CNBX diagnoses. FNA correctly classified 12 of 14 malignant sarcomas and four of 11 benign lesions. Diagnoses based on FNA were limited by a high proportion of samples, especially from benign lesions, that were inadequate for definitive diagnosis and by an inability to grade many malignant sarcomas. There were no significant complications resulting from the biopsies. We conclude that CNBX is a highly accurate, easily performed method for the diagnosis of large soft tissue masses that can be accomplished with minimal morbidity.

Adolescent↗
PubMed1992

Spin trap salvage from endotoxemia: the role of cytokine down-regulation.

BACKGROUND: The spin trap alpha-phenyl-N-tert-butyl-nitrone (PBN) affords protection from the lethality of septic (lipopolysaccharide) shock. We hypothesized that PBN may work through down-regulation of the sepsis-induced cytokine cascade. METHODS: C3H/HEN mice received 30 mg/kg lipopolysaccharide 15 minutes after pretreatment with PBN or vehicle. Animals were monitored for differences in behavior, histopathologic studies, survival, and serum levels of tumor necrosis factor (TNF-alpha), interferon-gamma (IFN-gamma), and interleukin-6 (IL-6) after lipopolysaccharide. Northern blot analyses of TNF, IFN-gamma, c-fos, and IL-6 transcripts were also performed. RESULTS: Seventy-two-hour survival was significantly higher in the PBN-treated (59/60) compared with the saline-treated animals (13/60; p2 less than 0.005), and the PBN group exhibited a blunted endotoxemic response. TNF levels were significantly lower in the PBN-treated animals at 1 to 6 hours, whereas IFN-gamma levels were depressed at 8 hours. PBN down-regulated TNF transcription at 30 minutes, with maximum lowering of all cytokine transcripts at 6 hours. PBN depressed c-fos transcription within 15 minutes of lipopolysaccharide injection. CONCLUSIONS: Spin trap protection from endotoxemia may be related to interruption of the cytokine network, with profound effects on transcription and protein elaboration. Such compounds may prove useful in not only sepsis but also other cytokine-free radical-related pathophysiologic alterations.

Animals↗
PubMed1991

Activating mutations of the stimulatory G protein in the McCune-Albright syndrome.

BACKGROUND: The McCune-Albright syndrome is a sporadic disease characterized by polyostotic fibrous dysplasia, café au lait spots, sexual precocity, and hyperfunction of multiple endocrine glands. These manifestations may be explained by a somatic mutation in affected tissues that results in activation of the signal-transduction pathway generating cyclic AMP (cAMP). We analyzed DNA from tissues of patients with the McCune-Albright syndrome for the presence of activating mutations of the gene for the alpha subunit of the G protein (Gs alpha) that stimulates cAMP formation. METHODS: Genomic DNA fragments encompassing regions (exons 8 and 9) previously found to contain activating missense mutations of the Gs alpha gene (gsp mutations) in sporadically occurring pituitary tumors were amplified in tissues from four patients with the McCune-Albright syndrome by the polymerase chain reaction. The amplified DNA was analyzed for mutations by denaturing gradient gel electrophoresis and allele-specific oligonucleotide hybridization. RESULTS: We detected one of two activating mutations within exon 8 of the Gs alpha gene in tissues from all four patients, including affected endocrine organs (gonads, adrenal glands, thyroid, and pituitary) and tissues not classically involved in the McCune-Albright syndrome. In two of the patients, histidine was substituted for arginine at position 201 of Gs alpha, and in the other two patients cysteine was substituted for the same arginine residue. In each patient the proportion of cells affected varied from tissue to tissue. In two endocrine organs, the highest proportion of mutant alleles was found in regions of abnormal cell proliferation. CONCLUSIONS: Mutations within exon 8 of the Gs alpha gene that result in increased activity of the Gs protein and increased cAMP formation are present in various tissues of patients with the McCune-Albright syndrome. Somatic mutation of this gene early in embryogenesis could result in the mosaic population of normal and mutant-bearing tissues that may underlie the clinical manifestations of this disease.

Adolescent↗
PubMed1991

Endometrial carcinoma with trophoblastic differentiation. An aggressive form of uterine cancer.

Three cases of poorly differentiated endometrial adenocarcinoma showing trophoblast-like differentiation are reported. The multinucleated, syncytiotrophoblast-like cells were strongly positive for beta-human chorionic gonadotropin (beta-HCG) by immunohistochemical study. High levels of beta-HCG were also present in the patients' serum, but dropped significantly after treatment. The patients had an unusually rapid and progressive clinical course with widespread dissemination and death by tumor.

Adenocarcinoma↗