Cyclin D1 in parathyroid disease

Primary hyperparathyroidism (HPT), most commonly due to parathyroid adenoma, is a disorder characterized by excessive secretion of PTH. So far, abnormalities in two genes, cyclin D1 and MEN1, have been implicated in the development of parathyroid adenomas. Cyclin D1, now an established Oncogene involved in numerous human cancers, was first identified and recognized as an Oncogene in the study of parathyroid tumors. A subset of parathyroid adenomas contains a clonal rearrangement that places the PTH gene's regulatory sequences in proximity to the cyclin D1 Oncogene causing its overexpression, and 20-40% of parathyroid adenomas overexpress the cyclin D1 protein. Transgenic animal models have further confirmed the role of cyclin D1 as a driver of abnormal parathyroid cell proliferation. Future studies on the mechanism of cyclin D1's oncogenicity and its interactions with other parathyroid growth regulators will further our understanding of parathyroid cell biology and may prove useful clinically.

Vitamin D receptor as a candidate tumor-suppressor gene in severe hyperparathyroidism of uremia

Most chronic renal failure patients with severe refractory hyperparathyroidism harbor at least one monoclonal parathyroid tumor, but the specific acquired genetic defects that confer this clonal selective advantage remain poorly understood. Somatic inactivation of the vitamin D receptor (VDR) gene could contribute to clonal outgrowth, because a parathyroid cell containing this lesion would have an impaired response to the antiproliferative influence of 1,25-dihydroxyvitamin D3. Furthermore, diminished expression of VDR protein has been described in uremia-associated parathyroid tumors. Therefore, to assess VDR gene inactivation's potential pathogenetic role in this disease, we rigorously analyzed the VDR gene in 59 parathyroid tumors surgically resected from uremic patients. First, Southern blotting and/or PCR analyses of 29 tumor samples from 14 genetically informative patients revealed no allelic losses at the VDR locus. Next, direct DNA sequencing of all VDR splice junctions, associated intronic sequences, and virtually the entire VDR-coding region for all 59 tumors revealed no acquired mutations. Last, 37 tumor DNA samples were subjected to comparative genomic hybridization, and no chromosomal losses in the VDR region (12cen-q12) were observed. These observations suggest that inactivating defects within the VDR gene do not commonly contribute to the primary pathogenesis of severe refractory hyperparathyroidism in uremia.

The mercury sphygmomanometer should be abandoned before it is proscribed

Both in clinical practice and medical research, blood pressure is still largely measured by auscultation using a mercury sphygmomanometer. Blood pressure is the most important predictor of life expectancy. Treatment of high blood pressure reduces strokes, heart attack and heart failure. Accurate measurement is therefore essential. At a large London teaching hospital, just under 500 mercury sphygmomanometers and their associated cuffs were examined. More than half had serious problems that would have rendered them inaccurate in measuring blood pressure. At the same time, assessment of the technical knowledge needed to measure blood pressure by the ausculatory technique was also carried out amongst medical and nursing staff. This showed a considerable level of ignorance. These results inevitably lead to inaccurate measurement of blood pressure with serious consequences. In addition mercury is a non-degradable pollutant, eventually accumulating on the sea bed. The use of mercury in sphygmomanometers is already in the process of being eliminated in Scandinavia and Holland and other countries are likely to follow. Our results suggest that mercury sphygmomanometers are not adequately maintained and require expertise that is not available for accurate measurement of blood pressure. Their use should be dispensed with on these grounds before a ban for other and, perhaps less justifiable reasons. Validated automatic devices, which are less liable to measurement and observer error should be used instead. At the same time a concerted effort is needed to instruct health care professionals on the importance of more accurate measurement of blood pressure. Journal of Human Hypertension (2000) 14, 31-36.

Lessons learned from enrollment in the BEST study--a multicenter, randomized trial of group psychosocial support in metastatic breast cancer

The BEST study, a multicenter randomized trial of group psychosocial support in metastatic breast cancer, had several unusual features that may have influenced recruitment, notably the group nature of the intervention and the need for close collaboration between medical and psychosocial investigators. The recruitment process was examined in light of these features. Establishment of study centers was facilitated by involvement of experienced medical investigators who had successfully collaborated in previous research projects. Systematic evaluation of potential subjects or direct recruitment by psychosocial investigators optimized recruitment; however, the group nature of the intervention prolonged recruitment. Overall, 652 women were approached and 237 (43.3% of those medically eligible) randomized. Using population-based estimates, 24.3% of women with metastatic breast cancer were assessed for the study and 8.7% randomized. A randomization ratio of 2:1 was required to form and maintain groups. Competing clinical trials were the greatest barrier to recruitment. Five lessons were learned during recruitment for this trial: (1) multicenter randomized trials of psychosocial interventions are feasible, even in very ill patients, (2) the use of a group intervention effectively increased the required sample size by 50%, (3) similarity of randomization rates suggests that generalizability of study results will probably be comparable to that of other randomized cancer trials, (4) multidisciplinary collaborations and involvement of experienced researchers facilitated enrollment, and (5) most challenges encountered in recruitment were similar to those seen in all clinical trials.

Plasmapheresis with a substitution solution of human serum protein (5%) versus plasmapheresis with a substitution solution of human albumin (5%) in patients suffering from autoimmune diseases

Therapeutic plasma exchange (TPE) has been used extensively for over 2 decades to treat a variety of autoimmune and congenital diseases and is now widely accepted. The primary objective of this study was to compare the clinical efficacy of two plasma exchange preparations, human serum protein (HSP) and human albumin (HA). Twenty-four patients in the following disease categories underwent TPE using either HSP (Biseko, 5%) or HA (5%): systemic lupus erythematosus, 8; glomerulonephritis, 8; myasthenia gravis, 2; Guillain-Barré-syndrome, 2; recurrent iritis, 1; pemphigoid, 1; uveitis, 1; and vascular retinitis, 1. There was no statistically significant difference in the average number of TPEs needed in the HSP group (13.5) and HA (13.8) measured over the first 6 weeks of treatment. The secondary parameters, in particular the immunological parameters IgG and IgA, provided evidence that plasma exchange with HSP may have some advantages over HA, and confirmatory studies in a larger group of patients are indicated. Adverse events during TPE occurred in both the HAS group (4 patients) and the HA group (4 patients). However, patients in the HSP group were older (12.3 years), were suffering from more complicated autoimmune diseases, and the number of occasions (days) on which these were reported (6 days) was less than in the HA group (11 days). One patient in the HA group died from septic-toxic circulatory collapse on Day 49 due to an infection with resistant strains of Staphylococcus aureus. Infections in other patients did not occur; all showed considerable improvement in their symptoms and completed the study in good general condition.

Differences between men and women in the management of unstable angina pectoris (The GUARANTEE Registry). The GUARANTEE Investigators

Few data are available in prospectively collected cohorts of patients with unstable angina pectoris or on the use of appropriate medications or interventions. Accordingly, we evaluated 2,948 consecutive patients with unstable angina admitted to 35 hospitals in the United States in 1996, and comparing men and women (39% of the patients were women). Differences were seen in coronary risk profiles with a higher incidence of systemic hypertension, diabetes mellitus, and a family history of coronary disease in women. Women were less likely to receive Agency for Health Care Policy Research (AHCPR) recommended pharmacologic treatment than men. Cardiac catheterization, coronary angioplasty, and bypass was performed less often in women compared with men (44% vs. 53%, p = 0.002; 12% vs. 18%, p = 0.02; 7% vs. 10%, p = 0.001, respectively). At catheterization, women were more likely to have no significant coronary artery disease (25% vs. 14%, p = 0.001). Although fewer women than men fulfilled the AHCPR criteria for cardiac catheterization (54% vs. 64%, p = 0.001), a similar rate of men and women with positive criteria underwent catheterization and angioplasty. However, fewer women with positive criteria underwent bypass surgery (36% vs. 46%, p = 0.03). More men "ruled-in" for a myocardial infarction at admission (13% vs. 8%, p = 0.001), but there was no difference in recurrent angina, in-hospital myocardial infarction, or death. Despite different epidemiologic profiles and less evidence of coronary artery disease by noninvasive and invasive tests, women and men had similar outcomes.

Phase II trial of N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine.HCl and doxorubicin chemotherapy in metastatic breast cancer: A National Cancer Institute of Canada clinical trials group study

PURPOSE

This multicenter phase II trial investigated the efficacy and toxicity of a combination of the novel intracellular histamine antagonist, N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine.HCl (DPPE), and doxorubicin in patients with anthracycline-naïve metastatic breast cancer. Preclinical models and early single institutional studies suggested DPPE could potentiate the cytotoxicity of doxorubicin.

PATIENTS AND METHODS

Forty-two women, 32 to 77 years old (median, 59 years), with anthracycline-naïve metastatic breast cancer were treated. Patients may have had one previous regimen of nonanthracycline chemotherapy, either in the adjuvant or metastatic disease treatment setting. DPPE (6 mg/kg) was administered as an 80 minute intravenous infusion with doxorubicin (60 mg/m(2)) given intravenously over the last 20 minutes of the DPPE infusion. Patients were premedicated with an antiemetic and sedating regimen. The DPPE/doxorubicin treatment was given every 21 days for a maximum of seven cycles.

RESULTS

All 42 patients were assessable. Overall, toxicity was comparable to that expected with doxorubicin alone, with the exception of DPPE-related motion sickness, mild hallucinations, and cerebellar signs at the time of the infusion. These CNS side effects were manageable in an ambulatory care setting, improved with subsequent cycles of treatment, and did not usually require hospitalization. Four patients developed febrile neutropenia. Thirty-five patients received four or more cycles of chemotherapy. The overall response rate was 52.5% (95% confidence interval, 36% to 68%), with 9.5% complete responses (n = 4), 43% partial responses (n = 18), and 38% of patients with stable disease (n = 16).

CONCLUSION

The antitumour effects of DPPE/doxorubicin the 52.5% response rate seems encouraging, particularly in consideration of the fact that a recently reported randomized National Cancer Institute of Canada Clinical Trials Group trial using single-agent doxorubicin 60 mg/m(2) in one of the treatment arms achieved a 31% response rate. Thus, a randomized phase III trial of doxorubicin versus doxorubicin plus DPPE is being conducted in this clinical setting.

RAD51 as a candidate parathyroid tumour suppressor gene on chromosome 15q: absence of somatic mutations

OBJECTIVE

Loss of heterozygosity (LOH) at chromosome 15q is frequent in parathyroid adenomas, but no tumour suppressor gene of importance to parathyroid tumour development has been isolated from this region. The RAD51 gene has been localized to chromosome 15q and possesses regulatory functions involving DNA stability and cell proliferation, suggesting its possible role in tumorigenesis. Additionally, mutations in the RAD51 gene cause reduced resistance to ionizing radiation, which is a major risk factor for primary hyperparathyroidism. RAD51 was therefore analysed as a candidate tumour suppressor gene in a group of parathyroid adenomas for which mutations in a 15q tumour suppressor should be most readily detectable.

PATIENTS AND DESIGN

From a total of 55 parathyroid adenomas, nine were selected based on their LOH pattern showing DNA loss at chromosome 15q in the vicinity of the RAD51 gene. RAD51 mRNA expression was investigated by reverse transcription-polymerase chain reaction (RT-PCR), and sequence analysis of the entire coding region of the RAD51 cDNA was performed in all nine adenomas.

RESULTS

RAD51 mRNA expression was substantiated in all parathyroid adenomas. Compared with the normal RAD51 cDNA sequence, no point mutations or microdeletions could be found in the parathyroid tumor cDNA.

CONCLUSION

These observations suggest that somatic inactivating mutations of the RAD51 gene are uncommonly, if ever, associated with parathyroid tumourigenesis.

Analysis of the RAD54 gene on chromosome 1p as a potential tumor-suppressor gene in parathyroid adenomas

Parathyroid adenomas causing primary hyperparathyroidism (pHPT) frequently exhibit allelic loss of DNA markers on the short arm of chromosome 1, indicating the presence of one or more tumor-suppressor genes on 1p. Since the development of pHPT is enhanced in individuals exposed to ionizing radiation to the neck, it could be anticipated that genes involved in DNA repair and recombination may be special targets for mutation in parathyroid tumorigenesis, whether irradiation-associated or not. RAD54 is a member of a family of genes involved in such functions, and RAD54 knockout mice show increased sensitivity to ionizing radiation. The localization of the RAD54 gene to 1p32 has therefore elevated it to a most compelling candidate parathyroid tumor-suppressor gene. Twelve parathyroid adenomas demonstrating allelic loss at chromosome 1p were selected from 55 parathyroid adenomas previously analyzed for loss of heterozygosity using polymorphic microsatellite markers. All 18 exons of the RAD54 gene were fully analyzed by automated sequencing for detection of point mutations or micro-deletions in each parathyroid adenoma. No mutational aberrations were detected in the RAD54 gene, strongly suggesting that complete somatic inactivation of RAD54 is infrequently, if ever, associated with the development of parathyroid adenomas. Whether genes controlling DNA repair and recombination are involved in parathyroid neoplasia remains to be determined.

Dosimetry of blood irradiation with radiochromic film

It has been shown that radiochromic film is an ideal dosimeter for assessment and verification of delivered dose to irradiated blood products. Using a parallel opposing two-field technique on a medical linear accelerator, blood is irradiated to diminish the risk of transfusion-associated graft vs. host disease (TA-GVHD). The blood products are irradiated in a Perspex blood box to an applied dose of 29.5-31.7 Gy. Verification of applied dose has been performed with thimble ionization chambers and radiochromic film. Radiochromic film results have matched absorbed dose measurements from ionization chambers at all sites within the 'active' treatment volume within +/-6% for a 95% confidence limit. Using a sample of 100 in-vitro measurements, radiochromic film has measured the average applied dose to blood products to be 30.95+/-2.6 Gy for two standard deviations. Like currently available 'irradiated' film labels, the radiochromic film also serves as a visible reminder that the blood products have been irradiated.

Offering a choice between two adjuvant chemotherapy regimens: a pilot study to develop a decision aid for women with breast cancer

BACKGROUND

The primary objective of this study was to develop a decision aid which would encourage and assist patients to become involved in treatment decision making, and help clinicians to objectively educate patients about the benefits and risks of adjuvant chemotherapy for breast cancer. A secondary objective was to investigate the factors influencing this treatment decision-making process for women when choosing between adriamycin and cyclophosphamide (AC) versus cyclophosphamide, methotrexate and 5-fluorouracil (CMF) chemotherapy.

METHODS

An educational visual instrument called a Decision Board was developed consisting of written and graphical material. The Decision Board displays general information about chemotherapy and detailed information about each chemotherapy regimen, including the schedule and side effects, and was presented to patients with a scripted standardized oral explanation. The instrument was evaluated in 46 premenopausal women newly diagnosed with node-positive breast cancer. Following presentation of the board, the patients were given a take home version to review and asked to return 1-2 weeks later with a decision. During the second visit each patient was asked to complete a questionnaire regarding demographics, learning and comprehension, treatment preference, and factors influencing their decision.

RESULTS

Recall of information was acceptable (> or = 80%). The Decision Board was found helpful by all, but the level of difficulty with decision making was variable. Out of 46 women, 23 women chose AC, 21 chose CMF, and two chose no treatment. The major factors affecting treatment preference were related to the impact on quality of life, the length of therapy, and the side effects, in particular, vomiting and alopecia.

CONCLUSIONS

The Decision Board appears to be a valuable educational tool that enables patients to become well-informed and directly involved in their treatment decisions.

Cyclin D1/PRAD1/BCL-1 alternative transcript [B] protein product in B-lymphoid malignancies with t(11;14)(q13;q32) translocation

The cyclin-D1/PRAD1 oncogene, a key regulator of the G1-phase progression of the cell cycle, has been identified as the long-sought BCL-1 oncogene in B-cell malignancies with t(11;14)(q13;q32) translocation. A novel alternative spliced cyclin-D1 transcript, called transcript[b], has been identified. The level of the variant transcript[b] was lower than that of the originally reported cyclin-D1 transcript, called transcript[a], in several human non-lymphoid cancer cell lines but the endogenous cellular expression of transcript[b] products has not yet been determined. Northern-blot analysis and reverse-transcription-polymerase-chain-reaction (RT-PCR) analysis revealed that transcript[b] mRNA is well expressed in B-lymphoid cell lines with t(11;14)(q13;q32) translocation and at much lower or undetectable levels in other cells. Western-blot analysis using a human cyclin-D1-specific monoclonal antibody, which can recognize and distinguish the products of transcripts [a] and [b], strongly suggested that the transcript [b] protein is indeed expressed in these B-cell lines. The present study provides identification of the endogenous cellular expression of the cyclin-D1-transcript[b] protein and strongly suggests that this alternative form of cyclin D1 may play a significant role in the molecular pathogenesis of B-lymphoid malignancies with t(11;14)(q13;q32) translocation.

Radiotherapy dose compensation for lung patients

The purpose of the present paper is to provide a more homogeneous dose distribution in the target volume from compensated anterior and posterior fields while the healthy lung is spared by de-weighting the lateral fields. A compensation computation which used linear iterations to compute the most homogeneous dose distribution across the target volume was applied to produce optimum compensator designs. The equivalent tissue-air ratio (E-TAR) inhomogeneity correction was applied for the computations using a GE target series II planning computer. The compensators designed were tested for accuracy in a modified water/lung phantom using a scanning diode and an anthropomorphic phantom using thermoluminescent dosimeters. A comparison has been made between the compensated and uncompensated plans for the first nine patients who we have treated with this technique. The dose profiles produced by the computation agreed with the prediction of the computed isodose plans to within +/- 2% at the target depth. The thermoluminescent dosimeter (TLD)-measured results in the anthropomorphic phantom agreed with the planning computer within +/- 3%. A comparison of nine compensated plans of radiotherapy patients for large-volume targets in the lung region showed a maximum variation in the target to be 19% uncompensated versus 10% compensated. By providing compensated treatment fields from anterior and posterior treatment portals, a homogeneous dose that conforms well to the target volume is provided. As an added bonus, this enables the lateral lung fields to be significantly de-weighted and the healthy lung is spared considerable dose.

Localization of putative tumor suppressor loci by genome-wide allelotyping in human pancreatic endocrine tumors

Only two tumor suppressor gene loci, one on 3p25 and the MEN1 gene on 11q13, have thus far been implicated in the pathogenesis of sporadic human pancreatic endocrine tumors (PETs). A genome-wide allelotyping study of 28 human PETs was undertaken to identify other potential tumor suppressor gene loci. In addition to those on chromosomes 3p and 11q, frequent allelic deletions were identified on 3q (32%), 11p (36%), 16p (36%), and 22q (29%). Finer deletion mapping studies localized the smallest regions of common deletion to 3q27, 11p13, and 16p12.3-13.11. Potential candidate genes at these loci include WT1 (11p13), TSC2 (16p13), and NF2 (22q12), but no known tumor suppressor gene localizes to 3q27. The mean fractional allelic loss among these human PETs is 0.126, and no correlation was observed between allelic loss and clinical parameters, including age, sex, hormonal subtype, and disease stage. These findings highlight novel locations of tumor suppressor gene loci that contribute to the pathogenesis of human PETs, and several of these on 3p, 3q, and 22q are syntenic with loci on mouse chromosomes 9 and 16 that are implicated in a murine transgenic model of PETs.

Randomized trial of intensive cyclophosphamide, epirubicin, and fluorouracil chemotherapy compared with cyclophosphamide, methotrexate, and fluorouracil in premenopausal women with node-positive breast cancer. National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To determine the relative efficacy of an intensive cyclophosphamide, epirubicin, and fluorouracil (CEF) adjuvant chemotherapy regimen compared with cyclophosphamide, methotrexate, and fluorouracil (CMF) in node-positive breast cancer.

PATIENTS AND METHODS

Premenopausal women with node-positive breast cancer were randomly allocated to receive either cyclophosphamide 100 mg/m2 orally days 1 through 14; methotrexate 40 mg/m2 intravenously (i.v.) days 1 and 8; and fluorouracil 600 mg/m2 i.v. days 1 and 8 or cyclophosphomide 75 mg/m2 orally days 1 through 14; epirubicin 60 mg/m2 i.v. days 1 and 8; and fluorouracil 500 mg/m2 i.v. days 1 and 8. Each cycle was administered monthly for 6 months. Patients administered CEF received antibiotic prophylaxis with cotrimoxazole two tablets twice a day for the duration of chemotherapy.

RESULTS

The median follow-up was 59 months. One hundred sixty-nine of the 359 CMF patients developed recurrence compared with 132 of the 351 CEF patients. The corresponding 5-year relapse-free survival rates were 53% and 63%, respectively (P = .009). One hundred seven CMF patients died compared with 85 CEF patients. The corresponding 5-year actuarial survival rates were 70% and 77%, respectively (P = .03). The rate of hospitalization for febrile neutropenia was 1.1% in the CMF group compared with 8.5% in the CEF group. There was one case of congestive heart failure in a patient who received CMF compared with none in the CEF group. Acute leukemia occurred in five patients in the CEF group.

CONCLUSION

The results of this trial show the superiority of CEF over CMF in terms of both disease-free and overall survival in premenopausal women with axillary node-positive breast cancer.

Frequent overexpression of the cyclin D1 oncogene in invasive lobular carcinoma of the breast

Invasive lobular carcinoma comprises approximately 10% of human mammary cancers, yet little is known about the molecular basis of this carcinoma. Because cyclin D1 plays a role in the pathogenesis of breast carcinomas of the ductal type, we hypothesized that this confirmed oncogene might also participate in the development of lobular carcinomas. We sought to determine the frequency of cyclin D1 protein overexpression in invasive lobular carcinoma, to investigate the cause of the protein accumulation, and to identify the effects of high levels of the protein on the regulation of the cell cycle. The study group comprises 27 indisputable cases of invasive lobular carcinoma showing varying degrees of cytological atypia. Immunohistochemical staining using well-characterized monoclonal and polyclonal antibodies disclosed cyclin D1 protein in the majority of the invasive lobular carcinoma cells in 80% of the tumors. In marked contrast, only rare cells of the noninvasive component (lobular carcinoma in situ) in the same tissue sections showed positive staining. Southern blotting of nine cases did not reveal evidence of cyclin D1 gene amplification. Immunohistochemical staining for Ki-67, a protein present in all dividing cells, showed that most cells positive for cyclin D1 did not stain for Ki-67. We conclude that the vast majority of invasive lobular carcinomas show overexpression of cyclin D1 protein. The absence of cyclin D1 protein expression in the noninvasive cells suggests that the molecule plays a role in the progression to the invasive form of lobular carcinoma. In contrast to the ductal types of breast cancer, cyclin D1 gene amplification does not seem to cause the cyclin D1 protein overexpression in lobular cancers. The lack of correlation between cyclin D1 and Ki-67 expression suggests that the cyclin D1 oncogene acts through mechanisms other than simple acceleration of the cell cycle clock in this subtype of human breast carcinoma.

A small deletion in the 3'-untranslated region of the cyclin D1/PRAD1/bcl-1 oncogene in a patient with chronic lymphocytic leukemia

The cyclin DI/PRAD1 oncogene, a key regulator of the G1 phase of the cell cycle, has been incriminated in the pathogenesis of human neoplasia. Cyclin D1 was also demonstrated to be identical to the long-sought bcl-1 oncogene in B-cell malignancies with the t(11;14)(q13;q32) translocation. We report here a small deletion in the 3'-untranslated portion of the cyclin D1 gene in leukemia cells of a patient diagnosed with B-chronic lymphocytic leukemia (CLL), associated with overexpression of the corresponding cyclin D1 mRNA. During a Northern blot survey of B-cell malignancies, we identified a patient whose CLL cells showed a marked increase in 1.5-1.6 kb cyclin D1 mRNA species. Subsequent Southern blot analysis showed that genomic DNA from the patient's cells contained an extra band in the EcoRI digest, suggesting that one allele of the cyclin D1 gene may be altered. Polymerase chain reaction (PCR) analysis of the genomic DNA and direct DNA sequencing clearly disclosed that one allele of the cyclin D1 gene was deleted in the 3'-untranslated region, which would contribute to an increased stability of its mRNA. Reverse transcription-polymerase chain reaction (RT-PCR) analysis and direct DNA sequencing revealed that the cyclin D1 mRNA was deleted at the corresponding region. This finding provides further evidence for a critical role of cyclin D1 in the pathogenesis of B-cell malignancies and highlights a novel mechanism, a small deletion in the 3'-untranslated region, responsible for deregulation of the cyclin D1 gene in oncogenesis.

A phase I trial of high-dose paclitaxel, cyclophosphamide and mitoxantrone with autologous blood stem cell support for the treatment of metastatic breast cancer

The aim of this phase I study was to determine the dose limiting toxicity (DLT), maximum tolerated dose (MTD) and efficacy of a new combination of cyclophosphamide (6 g/m2), mitoxantrone (70 mg/m2), with dose escalation of paclitaxel (TaxolR) at a starting dose of 250 mg/m2 given intravenously over 3 h in a transplantation setting. Patients with metastatic breast cancer and chemosensitive disease were eligible. The autologous blood stem cell re-infusion and subsequent recovery occurred in an out-patient setting. 50 patients were enrolled, but 10 withdrew. 40 completed the entire protocol. At 400 mg/m2 paclitaxel administered over 3 h, 3 of 6 patients experienced serious adverse events: approximately 20-40 min after completion of infusion, diaphoresis, bradycardia mild hypotension and diarrhoea occurred; 2 patients lost consciousness for a few minutes. An extended infusion schedule delivering 400 mg/m2 paclitaxel over 6 h rather than 3 h was initiated at this level without patients experiencing this DLT. At the next dose of 450 mg/m2 paclitaxel over 6 h, the same DLT was seen as at 400 mg/m2 paclitaxel over 3 h and, therefore, MTD was reached. Time to recovery for the absolute neutrophil count > or = 0.5 x 10(9)/l was 10-19 days (median 12 days); and for platelets > or = 20 x 10(9)/l was 18-20 days (median 11.5 days). 21 patients developed neutropenic fever that required intravenous antibiotics and re-admission; the transfusion frequency for packed red blood cell was 0-5 units (median 2 units) and for platelets, 1-5 encounters (median 2). 13 complete responses, 1 patient with no evidence of disease and 19 partial remissions were documented. The dose of 400 mg/m2 at an infusion rate of 6 h will be used for the ongoing phase II study to evaluate efficacy and toxicity further.

How long should Atrovent be given in acute asthma?

BACKGROUND

In acute asthma the optimal duration of treatment with combination beta agonist and anticholinergic nebuliser solutions is unknown; most studies have investigated single doses or treatment for up to 12 hours. To determine whether longer treatment with ipratropium bromide might aid recovery a study was undertaken in 106 patients with acute asthma.

METHODS

A double blind, randomised, placebo controlled, three group study was performed with all patients receiving ipratropium for 12 hours and salbutamol for 60 hours after admission (both nebulised four hourly), systemic steroids and, if necessary, theophylline. At 12 hours ipratropium was stopped in group I (n = 35) but was continued in the other two groups, and at 36 hours ipratropium was also stopped in group II (n = 35) while patients in group III (n = 36) continued with ipratropium for 60 hours. Spirometric tests were performed before and after salbutamol, and again 30 and 60 minutes after ipratropium or placebo at 12, 36 and 60 hours. Peak flow rates (PEFR) were measured before and after each nebulisation.

RESULTS

There were no differences between the groups in PEFR on admission (group I: 214 l/min, group II: 198 l/min, group III: 221 l/min), or mean forced expiratory volume in one second (FEV1) at 12 hours (group I: 1.81, group II: 2.01, group III: 2.21), 36 hours (group I: 2.11, group II: 2.31, group III: 2.41), or at 60 hours (group I: 2.21, group II: 2.31, group III 2.51). Despite this, median time to discharge was significantly higher for patients in group I (5.4 days) than for those in groups II (4.1 days) and III (4.0 days).

CONCLUSIONS

Combination nebulised therapy can be continued beyond 12 hours and up to 36 hours after admission with improved recovery time. Lung function testing may not reflect the full benefit of treatment.

Novel chromosomal abnormalities identified by comparative genomic hybridization in parathyroid adenomas

The molecular basis of parathyroid adenomatosis includes defects in the cyclin D1/PRAD1 and MEN1 genes but is, in large part, unknown. To identify new locations of parathyroid oncogenes or tumor suppressor genes, and to further establish the importance of DNA losses described by molecular allelotyping, we performed comparative genomic hybridization (CGH) on a panel of 53 typical sporadic (nonfamilial) parathyroid adenomas. CGH is a new molecular cytogenetic technique in which the entire tumor genome is screened for chromosomal gains and/or losses. Two abnormalities, not previously described, were found recurrently: gain of chromosome 16p (6 of 53 tumors, or 11%) and gain of chromosome 19p (5 of 53, or 9%). Losses were found frequently on 11p (14 of 53, or 26%), as well as 11q (18 of 53, or 34%). Recurrent losses were also seen on chromosomes 1p, 1q, 6q, 9p, 9q, 13q, and 15q, with frequencies ranging from 8-19%. Twenty-four of the 53 adenomas were also extensively analyzed with polymorphic microsatellite markers for allelic losses, either in this study (11 cases) or previously (13 cases). Molecular allelotyping results were highly concordant with CGH results in these tumors (concordance level of 97.5% for all informative markers/chromosome arms examined). In conclusion, CGH has identified the first two known chromosomal gain defects in parathyroid adenomas, suggesting the existence of direct-acting parathyroid oncogenes on chromosomes 16 and 19. CGH has confirmed the locations of putative parathyroid tumor suppressor genes, also defined by molecular allelotyping, on chromosomes 1p, 6q, 9p, 11q, 13q, and 15q. Finally, CGH has provided new evidence favoring the possibility that distinct parathyroid tumor suppressors exist on 1p and 1q, and has raised the possibility of a parathyroid tumor suppressor gene on 11p, distinct from the MEN1 gene on 11q. CGH can identify recurrent genetic abnormalities in hyperparathyroidism, especially chromosomal gains, that other methods to not detect.

Mechanism of cyclin D1 (CCND1, PRAD1) overexpression in human cancer cells: analysis of allele-specific expression

The cyclin D1/CCND1 oncogene (PRAD1) is amplified in 15% of primary human breast cancers and overexpressed in 30-50% of breast cancers, suggesting that mechanisms in addition to DNA amplification may lead to deregulated expression of this gene in breast cancer. Cyclin D1 overexpression at a higher frequency than gene amplification is also seen in a variety of other tumors. Cyclin D1 overexpression without amplification could result from a trans-acting regulatory disturbance or could be a consequence of a clonal regulatory mutation in one allele of the gene. We have, therefore, examined whether the overexpression of cyclin D1 mRNA is derived from one parental allele or both alleles in tumor cell lines with or without amplification of the cyclin D1 gene. Eight tumor cell lines, MCF-7, SK-BR-3, ZR-75-1, U-2-OS, SK-LMS-1, DLD1, HCT15, and HT29, out of 20 tumor cells initially examined were found to be heterozygous at the polymorphic NciI site within exon 4 of the cyclin D1 gene. Polymerase chain reaction and NciI digestion (PCR-RFLP) analysis of genomic DNA demonstrated DNA amplification of one allele in the ZR-75-1 cells and HT29 cells and no such imbalance in cyclin D1 gene copy number in the other cells, consistent with Southern blot analyses. Reverse-transcription polymerase chain reaction analysis and NciI digestion (RT-PCR-RFLP) of total cDNA revealed that the overexpressed cyclin D1 mRNA is preferentially derived from the amplified allele in the ZR-75-1 and HT29 cells. In contrast, the other tumor cells overexpressed cyclin D1 mRNA equally from both alleles. This finding strongly suggests that, in breast, sarcoma, and in colon cancer cells with cyclin D1 overexpression and normal gene copy number, elevated levels of cyclin D1 mRNA result from a trans-acting influence on both alleles rather than a clonal somatic mutation or rearrangement in or near a single cyclin D1 gene.