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H S Smith

Publications and source records attributed to H S Smith.

At least 19 recordsLinked to original sources
PubMed1992

ERBB2 amplification in breast cancer analyzed by fluorescence in situ hybridization.

We illustrate the use of fluorescence in situ hybridization (FISH) for analysis of ERBB2 oncogene copy number, the level of amplification (here defined as the ratio of ERBB2 copy number to copy number of chromosome 17 centromeres), and the distribution of amplified genes in breast cancer cell lines and uncultured primary breast carcinomas. The relative ERBB2 copy number determined by FISH in 10 breast cancer cell lines correlated strongly with Southern blot results (r = 0.98) when probes for an identical reference locus were used in the two methods. Metaphase analysis of cell lines showed that amplified ERBB2 copies always occurred in intrachromosomal clusters but that the number and chromosomal location of these clusters varied among the cell lines. In interphase nuclei of primary tumors showing ERBB2 amplification (10/44), ERBB2 copies were seen as one to four clusters, also suggesting intrachromosomal localization. Regardless of the average level of amplification, all these tumors contained highly amplified cell subpopulations with at least 25, and sometimes more than 100, ERBB2 copies per cell. Tumors that did not show amplification by FISH (34/44) had an average of one to five ERBB2 copies scattered randomly in the nuclei and completely lacked cells with high copy levels. FISH results on primary tumors were concordant with slot blot results on amplification and with immunohistochemical detection of overexpression. Quantitative analysis of ERBB2 amplification by FISH may improve prognostic assessments based on the pattern of amplification and detection of heavily amplified tumor cell subpopulations.

Breast Neoplasms↗
PubMed1992

Deletion of chromosome 17p loci in breast cancer cells detected by fluorescence in situ hybridization.

Allelic loss of tumor suppressor genes on chromosome 17p has been implicated in the progression of breast cancer. This is in principle detectable by fluorescence in situ hybridization if the loss occurs by deletion. In order to determine if detectable deletions occur in primary breast cancer, we used dual-color hybridization with chromosome 17 pericentromeric and region-specific DNA probes to study 19 primary breast cancers. The copy numbers of 17 centromere and 17p13.1 sequences were compared with the loss of heterozygosity (LOH) for probe YNZ22 at 17p13.3 detected by restriction fragment length polymorphism. Nine of 11 cases showing LOH also showed the major population of nuclei with a deletion. The remaining two tumors with LOH were trisomic for both the centromere and 17p13.1 cosmid. In contrast, seven of eight tumors without LOH had no deletions by fluorescence in situ hybridization. These data suggest that the dominant mechanism of allelic loss at 17p in breast cancer is a physical deletion and that analysis of deletions by fluorescence in situ hybridization is a rapid and sensitive approach to studying chromosomal aberrations.

Alleles↗
PubMed1992

Heterogeneity for allelic loss in human breast cancer.

BACKGROUND: Loss of heterozygosity (LOH) at specific chromosomal regions in the tumor cells implicates the presence of tumor suppressor genes. However, it is also possible for an LOH to be randomly acquired and irrelevant to tumor development. PURPOSE: To determine whether a particular LOH in human breast carcinomas represents a loss of tumor suppressor gene or merely a random loss, we analyzed untreated primary breast cancers for LOH. METHODS: Ninety-eight primary human breast cancers from previously untreated patients were analyzed for LOH at 12 chromosomal regions including five randomly selected regions and seven regions previously reported in other cancer types and/or breast cancers. RESULTS: The baseline incidence of LOH was five out of 124 tests (4%) using randomly selected probes on chromosomes 1p, 2p, 4p, 11q, and Xq. Incidences of LOH significantly greater than background were seen in the following chromosomal regions: 22q (10 of 26 cases, 38%); 18p (five of 24 cases, 21%); 17p (30 of 59 cases, 51%); 13q (five of 14 cases, 36%); 3p (13 of 28 cases, 46%); and 1q (18 of 70 cases, 26%). In contrast to previous reports, the incidence of LOH was not significantly different from background for 11p15. In all cases, results were the same for metastatic lymph nodes and primary tumors, suggesting that the losses occurred early in the malignant progression. In cases with LOH at more than one locus, the same DNA sample often varied in degree of signal reduction for the missing alleles. CONCLUSION: These observations indicate the presence of both intertumor and intratumor heterogeneity for LOH.

Adult↗
PubMed1992

Hepatobiliary scintigraphy in pediatric liver transplant recipients.

The clinical usefulness of hepatobiliary scintigraphy was evaluated in pediatric liver transplant recipients. One hundred fifteen hepatobiliary scintigraphic studies were performed in 30 patients who received 22 whole liver and 16 segmental grafts. Parameters that were useful in predicting an adverse outcome were failure to visualize excreted radiopharmaceutical at or beyond the biliary anastomosis on a study performed within 24 hours after transplant, and persistent or increasing delay in the time of visualization of excreted radiopharmaceutical. Abnormalities of liver uptake and excretion were seen in rejection, but they were also seen in patients who remained well without rejection or parenchymal disease. Significant biliary leaks were identified in the three cases in which they were known to be present. In liver transplant recipients, hepatobiliary imaging is useful in predicting graft survival and identifying biliary leaks.

Adolescent↗
PubMed1992

I-131 MIBG imaging after bone marrow transplantation for neuroblastoma.

Thirty-one children with stage III and IV neuroblastoma were studied with iodine-131 metaiodobenzyl-guanidine (MIBG) scintigraphy, technetium-99m medronate scintigraphy, skeletal plain radiography, and computed tomography (CT) before and after bone marrow transplantation (BMT). Twenty-six pre-BMT and 90 post-BMT studies were reviewed. Fourteen patients were alive without tumor, and one patient died at 4 months while free of tumor. I-131 MIBG scans obtained before and after BMT were negative in eight of the 15 patients. Seven had positive I-131 MIBG scans obtained before BMT that became negative after BMT. Six of 15 patients had small, questionable lesions on CT scans of the chest or abdomen that never increased in size, and the I-131 MIBG scans remained negative. Sixteen children had progressive disease or relapse, including four in whom I-131 MIBG scans showed new abnormalities, four with persistently positive I-131 MIBG scans, and three who had negative I-131 MIBG scans at relapse. Two of the 16 patients initially had small lesions seen on abdominal CT scans that were not seen on I-131 MIBG scans; mass lesions were later seen at CT in these locations. Detectable I-131 MIBG uptake in abdominal and thoracic lesions was related to the diameter of the lesion. Both I-131 MIBG scintigraphy and CT should be used to evaluate patients with neuroblastoma who have undergone BMT.

3-Iodobenzylguanidine↗
PubMed1992

Detection of retinoblastoma gene copy number in metaphase chromosomes and interphase nuclei by fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH) was applied to detect the copy number of the retinoblastoma (RB1) tumor suppressor gene in metaphase chromosomes and interphase nuclei. We used 14 lambda phage clones spanning the whole RB1 gene region as a probe and obtained a specific hybridization signal in normal metaphase chromosomes at 13q14. Normal interphase nuclei showed two RB1 signals in about 90% of cases, whereas two cell lines with cytogenetically defined deletions involving the RB1 gene showed only one hybridization signal in about 80% of the nuclei. Analogous changes were detected in metaphase chromosomes. Multicolor FISH with subsets of the phage clones allowed visualization of subregions within the 200-kb gene in interphase nuclei. Analysis of clinical breast cancer samples showed that most of the cells contained two copies of the RB1 gene, even when restriction fragment length polymorphism analysis showed loss of heterozygosity (LOH) at the RB1 locus. This indicates that LOH at the RB1 locus in breast cancer cells probably involves mechanisms other than physical deletion.

Breast Neoplasms↗
PubMed1992

Pethidine as a spinal anaesthetic agent--a comparison with plain bupivacaine in patients undergoing transurethral resection of the prostate.

This study compares the anaesthetic effects of intrathecal pethidine or bupivacaine in patients undergoing surgery for transurethral resection of the prostate. Patients were randomly allocated to receive 3.5 ml of 0.5% plain bupivacaine or 1 mg kg-1 of 5% pethidine. The onset, extent and duration of sensory and motor blockade were studied. The cardiovascular and respiratory variables and frequency of side-effects were noted, both in the intra-operative period and the first 24 h of the post-operative period. There were no significant differences in intra-operative conditions or post-operative complications. The duration of block was significantly shorter with pethidine but was not associated with a difference in post-operative pain or analgesic requirements; this may have advantages when early post-operative mobility is indicated. We conclude that spinal pethidine is a satisfactory agent for transurethral resection of the prostate.

Aged↗
PubMed1992

A prospective evaluation of the failure rate of spinal anaesthesia for transurethral prostatic resection.

The rate of failed spinal anaesthesia, defined as the need for unplanned general anaesthesia, was evaluated in a prospective study involving 137 patients undergoing transurethral resection of the prostate (TURP). The incidence of sensations at the operative site which did not require general anaesthesia was also evaluated. Attention to details was emphasized in the technique. Patients randomly received either hyperbaric Niphanoid tetracaine (n = 74; 6 or 10 mg) or hyperbaric bupivacaine (n = 61; 6 mg), with or without adrenaline. General anaesthesia was necessary in one patient (0.72%). Twelve additional patients reported sensations at the operative site which were rapidly relieved by light intravenous supplementation with low doses of fentanyl and/or thiopentone. The patients reporting sensations did not differ in demographic characteristics, spinal technique, local anaesthetic, or degree of sensory or motor blockade. Addition of adrenaline to the 6-mg doses of both tetracaine and bupivacaine decreased the incidence of sensations at the operative site.

Aged↗
PubMed1991

Growth factor messenger RNA expression by human breast fibroblasts from benign and malignant lesions.

Breast tumors are a complex mix of epithelial, stromal, and vascular elements. We examined primary cultures of breast fibroblasts derived from benign and malignant lesions for expression of various growth factors. All fibroblast cultures, regardless of whether they were derived from benign or malignant lesions, expressed platelet-derived growth factor A chain, basic fibroblast growth factor, fibroblast growth factor 5, and transforming growth factor beta 1 mRNA. None expressed platelet-derived growth factor B chain or transforming growth factor alpha mRNA. However, examination of mRNA expression for the insulin-like growth factors revealed that 7 of 8 fibroblasts derived from benign lesions expressed insulin-like growth factor I (IGF-I) mRNA, while only 1 of 9 fibroblasts derived from malignancies expressed IGF-I mRNA. The opposite picture was seen for insulin-like growth factor II (IGF-II) mRNA expression, in which 1 of 9 benign-derived fibroblasts expressed IGF-II mRNA, while 5 of 9 malignant-derived fibroblasts expressed IGF-II. This correlated with previous in situ hybridization data, which showed IGF-I mRNA expression confined to the stroma of benign breast tissue. PDGF treatment of tumor fibroblasts resulted in a 3-fold increase in IGF-II mRNA. Thus there was an apparent dichotomy between IGF-I mRNA expression in the majority of fibroblasts derived from benign lesions and IGF-II mRNA expression in the majority of tumor-derived fibroblasts. Since the insulin-like growth factors are potent mitogens for breast tumor epithelial cells, this further supports the notion of a paracrine growth-promoting role for the insulin-like growth factors in breast lesions and suggests that IGF-II may be the more important growth promoter in malignant lesions.

Breast Diseases↗
PubMed1991

Early and late events in the development of human breast cancer.

We hypothesize that early events in the development of at least some human breast cancers involve faulty epithelial-mesenchymal interactions and that the stromal cells themselves play an active role in this abnormal process. In contrast, later events accelerating breast tumor progression may occur in association with genetic changes involving only the malignant epithelial cells. These conclusions arise from a review of the literature, our comparative studies of HA metabolism in fibroblasts cultured from either normal or malignant breast tissues, and from molecular-genetic studies performed on sequential specimens from a single patient and on a wide variety of human breast tumor samples. HA is a proteoglycan component of the ECM which is known to stimulate epithelial cell detachment and motility and is most abundant in fetal and rapidly growing tissues. We find that many breast cancer-derived fibroblasts are stimulated to produce HA in response to TGF-beta under conditions where HA accumulation by normal tissue fibroblasts is almost uniformly inhibited. In a single patient, we had the opportunity to examine three malignant effusions that occurred sequentially to identify genetic changes associated with the later stages of breast cancer progression. Although, common cytogenetic abnormalities were found in all the effusion samples, only the last effusion exhibited a loss of heterozygosity at the c-Ha-ras locus. In this case, the allelic loss correlated with improved growth in vitro of the primary cells and with ability to become a permanently established cell line.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1991

Molecular and cellular lesions associated with breast cancer progression.

Breast cancer may be more than one disease with differing etiologies. At the molecular level, breast cancer may be the result of a complex, dynamic, and stochastic process where there is more than one way to accomplish each of the steps necessary for malignant growth. The well documented biologic heterogeneity of breast cancers may arise from the many possible molecular changes that can accomplish a given step with variable efficiency. Alternatively, this heterogeneity may also reflect various possible orders of acquiring the sum of steps necessary for malignant growth. We have attempted to describe some of the molecular changes associated with breast cancer in the context of this broad conceptual framework. We have found that the capacity for infinite growth in culture usually occurs at a late stage of malignant progression and is frequently associated with activating ras mutations. Loss of heterozygosity at chromosome 11p can occur either early or late in progression, while losses at chromosome loci 1q and 17p, although independent of each other, are found in primary breast cancers. Whether the same molecular and cellular changes are to be found in Japanese patients remains to be determined.

Alleles↗
PubMed1991

The promoter of DNA puff gene II/9-1 of Sciara coprophila is inducible by ecdysone in late prepupal salivary glands of Drosophila melanogaster.

DNA puffs occur in Sciarid salivary gland chromosomes; they are sites of DNA amplification and intense transcription and they appear to encode secreted structural proteins needed for pupation. In this report we have used P-element transformation of Drosophila to study regulation of a Sciara DNA puff gene. We found that a 718-bp promoter fragment of DNA puff gene II/9-1 from Sciara coprophila directs expression of the bacterial reporter gene CAT in late prepupal salivary glands of transgenic Drosophila melanogaster. The identical tissue and analogous stage specificity indicate that some aspects of the ecdysone response are evolutionarily conserved between Drosophila and Sciara. When transgenic salivary glands are cultured in vitro, CAT activity is rapidly induced by ecdysone, suggesting direct control of gene expression by the ecdysone receptor. Putative stage-specific factors limit expression of the chimeric Sciara-CAT gene in transgenic Drosophila to late prepupae but not to third instar larvae when ecdysone titers are also high.

Age Factors↗
PubMed1991

"Superscan" appearance in distal renal tubular acidosis.

Distal renal tubular acidosis (RTA) is known to cause metabolic bone abnormalities. For the first time to our knowledge, a case of distal RTA is reported in association with a superscan on bone scintigraphy. Reported cases of metabolic bone diseases producing a superscan appearance were reviewed, and underlying mechanisms are discussed. We speculate that impaired hydrogen ion secretion in this patient with distal RTA subclinically increased bone turnover, contributing to the superscan appearance on bone scintigraphy.

Acidosis, Renal Tubular↗
PubMed1991

The use of the Penlon Nuffield 200 in a monoplace hyperbaric oxygen chamber. An evaluation of its use and a clinical report in two patients requiring ventilation for carbon monoxide poisoning.

We modified a Penlon Nuffield 200 for use in a monoplace hyperbaric oxygen chamber by feeding back the chamber pressure to the reducing valve of the Nuffield 200. This provides a compensating mechanism, allowing the ventilator to deliver adequate tidal volumes at pressures of up to 3 atmospheres. We report the laboratory testing of the ventilator and our experience of ventilating two patients with carbon monoxide poisoning. Although compensation is not complete the modification is adequate for short-term clinical use in patients in whom the airway is compromised but who need hyperbaric oxygen therapy.

Adult↗
PubMed1991

A comparison between bromodeoxyuridine and 3H thymidine labeling in human breast tumors.

The fraction of tumor cells in the DNA synthesis (S) phase of the cell cycle is a strong prognostic indicator in human breast cancer. Most studies measuring S-phase in primary tumors have used either in vitro labeling with 3H thymidine or DNA flow cytometry. The former involves a cumbersome and time-consuming radioactive assay, while the latter is heavily dependent on the quality of the preparation and the effectiveness of the algorithms used. In this study, in vivo or in vitro labeling with bromodeoxyuridine (BrdUrd) was compared with in vitro labeling using 3H thymidine in a series of 33 human breast tumors. Thymidine labeling showed strong correlation with both in vitro (r = 0.96) and in vivo (r = 0.83) BrdUrd incorporation. The reliability between observers was higher for BrdUrd counting (r = 0.94) than for thymidine counting (r = 0.87). The mean labeling index of 15 tumors labeled in vivo with BrdUrd was 5.9% compared to 4.7% for 18 tumors labeled in vitro (p = 0.34). There was poor correlation between flow cytometric and microscopic analysis of BrdUrd incorporation (r = 0.37). We conclude that microscopic analysis of in vivo or in vitro BrdUrd incorporation is a rapid and reliable method to estimate breast tumor proliferation.

Analysis of Variance↗
PubMed1991

Proliferation of normal breast epithelial cells as shown by in vivo labeling with bromodeoxyuridine.

The proliferative activity of normal acinar and ductal breast epithelial cells was studied by in vivo labeling with 5-bromodeoxyuridine (BrdUrd) in 26 cases with concurrent breast carcinoma. The BrdUrd-labeled cells were recognized in histologic sections of paraffin-embedded tissue, using an anti-BrdUrd antibody and an immunoperoxidase reaction. The percentage of BrdUrd-labeled cells showed great variability for both acinar (0% to 2.66%; mean, 0.70%; standard deviation [SD], 0.80%) and ductal cells (0% to 1.99%; mean, 0.51%; SD, 0.57%). The fraction of proliferating epithelial cells declined with the age of the patients and was significantly higher in premenopausal women (1.16% +/- 0.85% for acinar and 0.94% +/- 0.60% for ductal cells) as compared with the postmenopausal women (0.27% +/- 0.46% for acinar and 0.17% +/- 0.22% for ductal cells), P less than 0.01 for acinar and P less than 0.001 for ductal cells, respectively. In some patients, great variability in distribution of proliferating acinar and ductal cells among different lobules and ducts was observed. No difference was found in the number of proliferating acinar and ductal cells situated near or far from their corresponding tumors. No correlation was seen between cell proliferation of normal acinar or ductal cells and cell proliferation of the respective tumors.

Adult↗
PubMed1990

Molecular, biochemical, and cellular biology of human breast cancer.

The meeting at Tamarron illustrated the multiplicity of molecular changes found in breast cancer and concluded with the disquieting sense that, so far, there is no simple unifying molecular model to explain the etiology of the disease. Perhaps the complex nature of breast cancer precludes formulation of a simple model. The biologic heterogeneity of breast cancers may reflect the fact that, at the molecular level, there is more than one way to accomplish each of the phenotypic changes necessary for malignant growth. At this point in time, it is difficult to evaluate which molecular changes will be important to understanding and subsequently interfering with the disease process. Additional studies correlating molecular and biochemical changes in human breast tumors with clinical disease characteristics and patient outcome should help to clarify these issues.

Breast Neoplasms↗