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L K Green

Publications and source records attributed to L K Green.

At least 37 records · Page 2Linked to original sources
PubMed1994

Non-specific fluorescent whitener stains in the rapid recognition of pulmonary dirofilariasis: a report of 20 cases.

BACKGROUND: Solitary lung nodules in humans caused by the dog parasite Dirofilaria immitis are steadily increasing in number. The organisms can be easily missed in haematoxylin and eosin stained tissue when they are degenerated and pale staining. METHODS: The value of Tinopal CBS-X (TCBS-X) and Calcofluor white (CFW), two rapid, inexpensive, simple non-specific fluorescent whitening stains, were assessed in the identification of these worms. Deparaffinised rehydrated tissue slides prepared from the pulmonary nodules were stained for one minute in 1% w/v aqueous solutions of TCBS-X or CFW, counterstained, coverslipped, and viewed with a fluorescent microscope. RESULTS: The stains demonstrated the intact worm and worm fragments in 20 cases of pulmonary dirofilariasis collected from hospitals in Houston. The filariae and fragments of filariae stained bright green while the background tissue stained red, delineating the internal structures of the worm. CONCLUSIONS: Dirofilariasis should be included in the differential diagnosis of subpleural masses, and non-specific fluorescent whitening stains can help in the rapid recognition of the fragmented organism in cytological or surgical material.

Adult↗
PubMed1992

Detection of an equilibrium intermediate in the folding of a monomeric insulin analog.

To determine the conformational properties of the C-terminal region of the insulin B-chain relative to the helical core of the molecule, we have investigated the fluorescence properties of an insulin analog in which amino acids B28 and B29 have been substituted with a tryptophan and proline residue respectively, ([WB28,PB29]insulin). The biological properties and far-UV circular dichroism (CD) spectrum of the molecule indicate that the conformation is similar to that of native human insulin. Guanidine hydrochloride (GdnHCl)-induced equilibrium denaturation of the analog as monitored by CD intensity at 224 nm indicates a single cooperative transition with a midpoint of 4.9 M GdnHCl. In contrast, when the equilibrium denaturation is observed by steady-state fluorescence emission intensity at 350 nm, two distinct transitions are observed. The first transition accounts for 60% of the observed signal and has a midpoint of 1.5 M GdnHCl. The second transition roughly parallels that observed by CD measurements with an approximate midpoint of 4.5 M GdnHCl. The near-UV CD spectrum, size-exclusion, and ultracentrifugation properties of [WB28,PB29]insulin indicate that this analog does not self-associate in a concentration-dependent manner as does human insulin. Thus, the observed fluorescence changes must be due to specific conformational transitions which occur upon unfolding of the insulin monomer with the product of the first transition representing a stable folding intermediate of this molecule.

Amino Acid Sequence↗
PubMed1992

Improved insulin stability through amino acid substitution.

Insulin analogs designed to decrease self-association and increase absorption rates from subcutaneous tissue were found to have altered stability. Replacement of HB10 with aspartic acid increased stability while substitutions at B28 and/or B29 were either comparable to insulin or had decreased stability. The principal chemical degradation product of accelerated storage conditions was a disulfide-linked multimer that was formed through a disulfide interchange reaction which resulted from beta-elimination of the disulfides. The maintenance of the native state of insulin was shown to be important in protecting the disulfides from reduction by dithiothreitol and implicitly from the disulfide interchange reaction that occurs during storage. To understand how these amino acid changes alter chemical stability, the intramolecular conformational equilibria of each analog was assessed by equilibrium denaturation. The Gibbs free energy of unfolding was compared with the chemical stability during storage for over 20 analogs. A significant positive correlation (R2 = 0.8 and P less than 0.0005) exists between the conformational stability and chemical stability of these analogs, indicating that the chemical stability of insulin's disulfides is under the thermodynamic control of the conformational equilibria.

Amino Acid Sequence↗
PubMed1992

Altering the association properties of insulin by amino acid replacement.

The importance of ProB28 and LysB29 on the self-association of insulin was established by systematically truncating the C terminus of the B chain. The relationship between structure and association was further explored by making numerous amino acid replacements at B28 and B29. Association was studied by circular dichroism, size-exclusion chromatography and ultracentrifugation. Our results show that the location of a prolyl residue at B28 is critical for high-affinity self-association. Removal of ProB28 in a series of C-terminal truncated insulins, or amino acid replacement of ProB28, greatly reduced association. The largest disruption to association was achieved by replacing LysB29 with Pro and varying the amino acid at B28. Several of the analogs were predominantly monomers in solutions up to 3 mg/ml. These amino acid substitutions decreased association by primarily disrupting the formation of dimers. Such amino acid substitutions also substantially reduced the Zn-induced insulin hexamer formation. The formation of monomeric insulins through amino acid replacements was accompanied by conformational changes that may be the cause for decreased association. It is demonstrated that self-association of insulin can be drastically altered by substitution of one or two key amino acids.

Amino Acid Sequence↗
PubMed1991

Primary angiosarcoma of the cuboidal bone: a case report.

Primary angiosarcoma of bone is a rare neoplasm. The unique cytomorphologic and ultrastructural aspects of a primary angiosarcoma of the cuboid bone diagnosed by fine-needle aspiration are presented. Smears and cell block preparations revealed single and clustered large, pleomorphic, and spindle-shaped cells with a markedly hemorrhagic background. Electron microscopy revealed characteristic features of endothelial cells including rare Weibel-Palade bodies. The clinical, cytologic, histologic, and ultrastructural aspects of the case are discussed.

Aged↗
PubMed1991

The use of immunohistochemistry in metastatic prostatic adenocarcinoma to the breast.

Since the introduction of hormonal therapy for the treatment of metastatic prostatic adenocarcinoma, there have been 33 reports of metastases of prostate carcinoma to the breast. We report two cases of diethylstilbestrol (DES)-treated patients with metastatic prostate adenocarcinoma who developed breast masses. The lesions had infiltrative patterns simulating primary breast carcinoma. Immunoperoxidase stains, prostate-specific antigen (PSA), and prostatic acid phosphatase (PAP) were positive, identifying these cases as metastatic prostatic carcinoma to the breast. Differentiating primary from secondary tumors in these patients is difficult since there have been 10 reports of primary breast carcinoma occurring in DES-treated patients with prostatic adenocarcinoma. Their differentiation is important to direct appropriate therapy, and PSA and PAP immunoperoxidase stains are important in their correct classification.

Acid Phosphatase↗
PubMed1991

Peripheral mucoepidermoid tumour of the lung.

Mucoepidermoid tumours of the bronchial tree are uncommon neoplasms, which are believed to arise from terminal ducts of the proximal tracheobronchial tree. The first case of a peripheral mucoepidermoid tumour of the lung is reported.

Carcinoma↗
PubMed1990

Hematogenous metastases to the stomach. A review of 67 cases.

Metastatic tumors to the mucosa of the stomach are unusual occurrences that can cause clinical and pathologic problems in diagnosis. The authors report 67 cases from the files of the Veterans Administration Center at Houston. Ten cases were found on endoscopic biopsy and 57 at necropsy. Each patient endoscopically evaluated presented with upper gastrointestinal tract symptoms, including bleeding, abdominal pain, anorexia, and vomiting. At endoscopic examination, characteristic "volcano-like" ulcers were noted. Clinical gastrointestinal symptoms were present in 30 of the necropsy cases, and in four cases the gastric metastases led to the patients' deaths. Tumors primary in the lung accounted for most of the metastases (55%), followed by other gastrointestinal malignancies. A correct diagnosis is important to direct therapy and is facilitated by the characteristic clinical, endoscopic, and histologic findings.

Female↗
PubMed1990

The use of gastric salvage cytology in the diagnosis of malignancy: a review of 731 cases.

Over an 8-yr period at the Houston Veterans Hospital, 731 endoscopic gastric salvage cytologies were performed in 671 patients, with surgical biopsy also done in 660. Seventy-six patients subsequently had tissue biopsy-proven or resection-proven malignancies. Salvage cytology had a sensitivity of 91% and a specificity of 100% for the detection of primary adenocarcinoma. Biopsy alone had a sensitivity of 92%; endoscopic gastric salvage cytology and surgical biopsy combined had a sensitivity of 100% in both primary and metastatic neoplasms. This study shows that the combination of endoscopic biopsy and salvage cytology increases the diagnostic accuracy for gastric carcinoma. Gastric salvage cytology requires minimal disruption of the routine endoscopic procedure and is therefore an easier and more rapid cytologic technique than gastric brushing cytology.

Adenocarcinoma↗
PubMed1990

Diagnosis of metastatic lesions to the stomach by salvage cytology. A report of three cases.

Secondary neoplasms of the stomach are rare and are often clinical and diagnostic problems. Three patients with bleeding "volcano-like" ulcers were diagnosed by combined endoscopic "salvage" cytology and surgical biopsy as having metastatic submucosal lesions from hematologic spread. The combination of endoscopic appearance, clinical findings, and tissue and cytologic examination can lead to the correct diagnosis. The results from these cases support the utility of this cytologic technique in combination with biopsy in this clinical setting.

Aged↗
PubMed1990

Gastritis in the elderly.

The elderly have an increased prevalence of gastritis and the complications associated with it. The two major classes of acute and chronic gastritis, type A and B, are discussed as they relate to clinical findings, histologic features, and pathogenesis. An age-related increase in the frequency of Helicobacter pylori (formerly Campylobacter pylori) infection in the elderly parallels the known age-related increase in the prevalence of gastritis. The close association between gastritis in the elderly and hypochlorhydria and gastric carcinoma is also explored.

Achlorhydria↗
PubMed1989

Renal cell carcinoma metastatic to the thyroid.

Metastatic renal cell carcinoma to the thyroid is an uncommon occurrence that can cause clinical and pathologic problems in diagnosis. The authors report seven cases from the files of The University of Texas M.D. Anderson Cancer Center, Houston, Texas. Each presented clinically as a palpable thyroid nodule months or years after the primary renal cell carcinoma had been resected. Although renal cell carcinoma is more common in men, we found a female predominance of 6:1 in this series. These lesions appear as solitary "cold" nodules on iodine 131 scans and may be misdiagnosed as primary thyroid neoplasms, especially if the renal primary is still unrecognized. A correct diagnosis is important because surgical management can be curative. The diagnosis is facilitated by the use of fat stains, electron microscopic study, and immunoperoxidase stains.

Aged↗
PubMed1989

DNA flow cytometry as a predictor of outcome of stage I renal cell carcinoma.

The features most frequently used in predicting the outcome of renal cell carcinoma are stage at presentation and nuclear grade. Recently DNA ploidy pattern, as detected by DNA flow cytometry has also been shown to be predictive. In this study DNA flow cytometry was performed on formalin-fixed paraffin-embedded tissue from 50 patients with Stage I renal cell carcinoma for whom long-term follow-up data were available. Two were eliminated for technical reasons. Of the 48 evaluable tumors, 25 (52%) were diploid, 19 (40%) were nondiploid, and in four, (8%) the ploidy was uncertain. The ploidy pattern was statistically significantly associated with nuclear grade (P less than 0.02), and primary tumor size (P less than 0.05) but did not correlate with cell type, microscopic growth pattern, or the presence or absence of mitotic activity. In the group as a whole, ten patients (21%) died of renal cell carcinoma, seven of 19 (37%) with nondiploid tumor patterns, and two of 25 (8%) with a diploid pattern (P less than 0.03). One of four patients (25%) with tumors of uncertain ploidy also died. However, only two factors, nuclear grade and primary tumor size, were independent predictors of outcome. For Stage I renal cell carcinoma, ploidy can significantly predict patient outcome and correlates with nuclear grade and tumor size, but is not an independent predictive variable.

Carcinoma, Renal Cell↗
PubMed1989

Role of nuclear grading in stage I renal cell carcinoma.

Through a retrospective histologic analysis of 55 cases of Stage I renal cell carcinoma, we evaluated the usefulness of the nuclear grading system (Fuhrman, Lasky, Limas) in identifying those tumors that will eventually metastasize and kill the patient. The difference in five-year survival rates between patients with combined nuclear grade 1-3 tumors (n = 50, 91%) and grade 4 tumors (n = 5, 9%) was significant (P less than 0.0046). Other predictors of death due to renal cell carcinoma included: tumor size greater than 8 cm (P less than 0.001) and mitoses greater than one per 10 high-power field (P less than 0.01). Within Stage I tumors, therefore, nuclear grade is an important morphologic variable for predicting long-term survival. Identification of nuclear grade 4 neoplasms may become prognostically indispensable to determine the metastatic potential of early-stage tumors and thereby to institute appropriate systemic therapy.

Adult↗
PubMed1989

Hepatoblastoma in an adult with metastasis to the ovaries.

A 19-year-old female had ascites, an enlarged liver, pelvic masses, and an alpha-fetoprotein level of 397,000 micrograms/L with a normal beta-human chorionic gonadotropin serum level. Abdominal exploration revealed a large solitary liver mass with bilateral ovarian masses, and bilateral salpingo-oophorectomy and wedge liver biopsy were performed. The tumor was composed of cords, nests, and pseudorosettes of polyhedral cells with eosinophilic cytoplasm and nuclei with prominent nucleoli. The clinical, light microscopic, and immunocytochemical features indicate that the primary liver neoplasm and ovarian metastases were a purely epithelial hepatoblastoma. To the authors' knowledge, this is the first reported case of this type.

Adolescent↗
PubMed1989

Histopathologic findings in ectopic tubal pregnancy.

In 141 consecutive cases of tubal ectopic pregnancy at Hermann Hospital in Houston, Texas, the histologic appearance of 129 surgically removed fallopian tubes containing ectopic pregnancies was reviewed and compared with an age- and race-matched control population. There was a higher incidence of chronic salpingitis (88 versus 2%) and salpingitis isthmica nodosa (SIN) (43 versus 5%). The ectopic pregnancy patients had a higher incidence of pelvic inflammatory disease, gonorrhea, previous abortions, bitubal ligation, intrauterine device use, and previous abdominal surgery. In our population, chronic salpingitis was the most commonly associated finding. The increase in SIN was associated with postinflammatory changes (89%). We also found that ectopic tubal pregnancies may grow either intratubally or extratubally by villous invasion into the wall and blood vessels; therefore, surgical salvage of the fallopian tube by extracting the products of conception will not always be curative.

Adolescent↗
PubMed1988

Pemphigus vulgaris. Combined treatment with intravenous corticosteroid pulse therapy, plasmapheresis, and azathioprine.

A 13-year-old child is described who presented with generalized pemphigus vulgaris associated with extraordinarily high titers of circulating autoantibodies against the pemphigus antigen. Because of the lack of response to treatment with reasonably high doses of oral corticosteroids, as well as the very high titer of circulating autoantibodies observed, this patient was treated with intravenous corticosteroid pulse therapy followed by plasmapheresis and then by combination immunosuppressive therapy (prednisone and azathioprine). A rapid clinical response was induced, correlating with reduction and subsequent elimination of the circulating pemphigus autoantibodies. Using such combination therapy, a remission of 12 months was achieved, and prednisone therapy was completely, albeit temporarily, tapered and then discontinued. Subsequent disease flare was then easily controlled with a short course of low-dose oral corticosteroid therapy.

Adolescent↗