Adjuvant radiotherapy and chemotherapy in node-positive premenopausal women with breast cancer

BACKGROUND

Radiotherapy after mastectomy to treat early breast cancer has been known since the 1940s to reduce rates of local relapse. However, the routine use of postoperative radiotherapy began to decline in the 1980s because it failed to improve overall survival. We prospectively tested the efficacy of combining radiotherapy with chemotherapy.

METHODS

From 1978 through 1986, 318 premenopausal women with node-positive breast cancer were randomly assigned, after modified radical mastectomy, to receive chemotherapy plus radiotherapy or chemotherapy alone. Radiotherapy was given to the chest wall and locoregional lymph nodes between the fourth and fifth cycles of cyclophosphamide, methotrexate, and fluorouracil.

RESULTS

After 15 years of follow-up, the women assigned to chemotherapy plus radiotherapy had a 33 percent reduction in the rate of recurrence (relative risk, 0.67; 95 percent confidence interval, 0.50 to 0.90) and a 29 percent reduction in mortality from breast cancer (relative risk, 0.71; 95 percent confidence interval, 0.51 to 0.99), as compared with the women treated with chemotherapy alone.

CONCLUSIONS

Radiotherapy combined with chemotherapy after modified radical mastectomy decreases rates of locoregional and systemic relapse and reduces mortality from breast cancer.

Generation and analysis of 280,000 human expressed sequence tags

We report the generation of 319,311 single-pass sequencing reactions (known as expressed sequence tags, or ESTs) obtained from the 5' and 3' ends of 194,031 human cDNA clones. Our goal has been to obtain tag sequences from many different genes and to deposit these in the publicly accessible Data Base for Expressed Sequence Tags. Highly efficient automatic screening of the data allows deposition of the annotated sequences without delay. Sequences have been generated from 26 oligo(dT) primed directionally cloned libraries, of which 18 were normalized. The libraries were constructed using mRNA isolated from 17 different tissues representing three developmental states. Comparisons of a subset of our data with nonredundant human mRNA and protein data bases show that the ESTs represent many known sequences and contain many that are novel. Analysis of protein families using Hidden Markov Models confirms this observation and supports the contention that although normalization reduces significantly the relative abundance of redundant cDNA clones, it does not result in the complete removal of members of gene families.

EGR2 mutations in inherited neuropathies dominant-negatively inhibit myelin gene expression

The identification of EGR2 mutations in patients with neuropathies and the phenotype Egr2/Krox20(-/-) have demonstrated that the Egr2 transcription factor is critical for peripheral nerve myelination. However, the mechanism by which these mutations cause disease remains unclear, as most patients present with disease in the heterozygous state, whereas Egr2(+/-) mice are phenotypically normal. To understand the effect of aberrant Egr2 activity on Schwann cell gene expression, we performed microarray expression profiling to identify genes regulated by Egr2 in Schwann cells. These include genes encoding myelin proteins and enzymes required for synthesis of normal myelin lipids. Using these newly identified targets, we have shown that neuropathy-associated EGR2 mutants dominant-negatively inhibit wild-type Egr2-mediated expression of essential myelin genes to levels sufficiently low to result in the abnormal myelination observed in these patients.

Targeting cancer micrometastases with monoclonal antibodies: a binding-site barrier

Monoclonal antibodies penetrate bulky tumors poorly after intravenous administration, in part because of specific binding to the target antigen. Experiments presented here demonstrate an analogous phenomenon in micrometastases; poor antibody penetration, attributable to a "binding-site barrier" phenomenon, can be seen in guinea pig micrometastases as small as 300 microns in diameter. Increasing the dose of antibody can partially overcome this limitation, but at a cost in specificity.

Rapamycin causes down-regulation of CCR5 and accumulation of anti-HIV beta-chemokines: an approach to suppress R5 strains of HIV-1

Propagation of R5 strains of HIV-1 on CD4 lymphocytes and macrophages requires expression of the CCR5 coreceptor on the cell surface. Individuals lacking CCR5 (CCR5 Delta 32 homozygous genotype) are phenotypically normal and resistant to infection with HIV-1. CCR5 expression on lymphocytes depends on signaling through the IL-2 receptor. By FACS analysis we demonstrate that rapamycin (RAPA), a drug that disrupts IL-2 receptor signaling, reduces CCR5 surface expression on T cells at concentrations as low as 1 nM. In addition, lower concentrations of RAPA (0.01 nM) were sufficient to reduce CCR5 surface expression on maturing monocytes. PCR analysis on peripheral blood mononuclear cells (PBMCs) showed that RAPA interfered with CCR5 expression at the transcriptional level. Reduced expression of CCR5 on PBMCs cultured in the presence of RAPA was associated with increased extracellular levels of macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta. In infectivity assays, RAPA suppressed the replication of R5 strains of HIV-1 both in PBMC and macrophage cultures. In total PBMC cultures, RAPA-mediated inhibition of CCR5-using strains of HIV-1 occurred at 0.01 nM, a concentration of drug that is approximately 103 times lower than therapeutic through levels of drug in renal transplant recipients. In addition, RAPA enhanced the antiviral activity of the CCR5 antagonist TAK-779. These results suggest that low concentrations of RAPA may have a role in both the treatment and prevention of HIV-1 infection.

The correlation between epidermal growth factor levels in saliva and the severity of oral mucositis during oropharyngeal radiation therapy

BACKGROUND

Epidermal growth factor (EGF) is present in biologic fluids, including saliva, and plays a role in maintenance of the epithelial barrier and in healing of damaged mucosa. The purpose of this study was to assess the relation between salivary EGF and the severity of oral mucositis in patients with carcinoma of the head and neck during radiation therapy.

METHODS

Whole resting saliva (WRS) and whole stimulated saliva (WSS) were collected prior to radiation and each week during radiation treatment for 11 men and 7 women. Oral mucositis was evaluated using the National Cancer Institute (NCI) scale of 0-4 and the Oral Mucositis Assessment Scale (OMAS), which evaluates the extent of erythema (scale of 0-2) and ulcerations (scale of 0-3) in nine oral sites. The overall OMAS score of 0-45 reflected the mucosal condition. EGF was assayed in the saliva specimens.

RESULTS

The total mean radiation dose delivered to the head and neck was 5667 centigrays (cGy) in a mean of 24 fractions. Ulcerative oral mucositis occurred in 94% of patients. The mean OMAS score ranged from 2.83 in the first week of treatment to 14.77 in the fifth week. The mean WRS and WSS volumes decreased significantly from pretreatment to the first week of radiation treatment and then remained stable. A similar pattern was seen for the mean total output of EGF. A significant and negative correlation was found between higher levels of EGF in stimulated saliva and low OMAS score, reflecting less severe erythema and ulceration. A general trend showing that less tissue damage was associated with a higher EGF level in resting saliva also was illustrated. EGF levels were correlated with the OMAS score; however, no correlation was found when assessing the NCI score, which combines tissue damage with function and symptoms in a single score.

CONCLUSIONS

Radiation-induced mucositis appeared to be modified by saliva volume, total EGF, and concentration of EGF in the oral environment. Saliva volume and total EGF output decreased significantly in the first weeks of treatment and remained reduced throughout radiation therapy. The findings suggest that higher levels of EGF in saliva, particularly in stimulated saliva, prior to and during radiation treatment may be associated with less severe mucosal damage due to radiation therapy. It is also postulated that human EGF may affect the development and healing of radiation-damaged mucosa.

The utility of toluidine blue application as a diagnostic aid in patients previously treated for upper oropharyngeal carcinoma

OBJECTIVES

This study evaluated the utility (usefulness) of toluidine blue application as an aid to the recognition and diagnosis of clinically evident lesions in a series of patients previously treated for oral cancer and monitored in a cancer center. In addition to increased risk of recurrence of cancer or new second primary lesions, patients who have had previous treatment for oropharyngeal cancer may be more difficult to assess because of tissue changes that occur as a result of previous radiation therapy.

STUDY DESIGN

Patients with a history of oral malignancy were assessed by clinical examination followed by application of toluidine blue. Biopsy sites were determined on the basis of unaided visual examination and by the findings on toluidine blue application. Biopsy specimens were reviewed by a pathologist blinded to the clinical findings.

RESULTS

Unaided clinical examination identified 78% of carcinoma in situ or invasive malignant lesions compared with toluidine blue application, which identified all (100%) carcinoma in situ or invasive malignant lesions (p = 0.02) and produced no false-negative findings. No differences were found between clinical examination and toluidine application in the detection of dysplastic lesions.

CONCLUSION

Toluidine blue retention was seen in all cases of carcinoma in situ and invasive carcinoma, and no false-negative findings were seen with toluidine blue. When used by a trained and experienced clinician in a cancer center, toluidine blue was a valuable visual aid to clinical examination of oral mucosal lesions.

The HIV protease inhibitor indinavir decreases insulin- and contraction-stimulated glucose transport in skeletal muscle

In many patients with human immunodeficiency virus (HIV) treated with HIV protease inhibitors, a complication develops that resembles abdominal obesity syndrome, with insulin resistance and glucose intolerance that, in some cases, progresses to diabetes. In this study, we tested the hypothesis that indinavir, an HIV-protease inhibitor, directly induces insulin resistance of glucose transport in skeletal muscle. Rat epitrochlearis muscles were incubated with a maximally effective insulin concentration (12 nmol/l) and 0, 1, 5, 20, or 40 micromol/l indinavir for 4 h. In control muscles, insulin increased 3-O-[(3)H]methyl-D-glucose (3MG) transport from 0.15 +/- 0.03 to 1.10 +/- 0.05 micromol. ml(-)(1). 10 min(-)(1). Incubation of muscles with 5 micromol/l indinavir reduced the insulin-stimulated increase in 3MG transport by 40%, whereas 20 micromol/l indinavir reduced the insulin-stimulated increase in 3MG transport by 58%. Indinavir induced a similar reduction in maximally insulin-stimulated 3MG transport in the soleus muscle. The increase in glucose transport activity induced by stimulating epitrochlearis muscles to contract was also markedly reduced by indinavir. The insulin-stimulated increase in cell-surface GLUT4, assessed using the 2-N-4-(1-azi-2,2,2-trifluoroethyl)benzoyl-1,3-bis-[2-(3)H] (D-mannose-4-yloxy)-2-propylamine exofacial photolabeling technique, was reduced by approximately 70% in the presence of 20 micromol/l indinavir. Insulin stimulation of phosphatidylinositol 3-kinase activity and phosphorylation of protein kinase B were not decreased by indinavir. These results provide evidence that indinavir inhibits the translocation or intrinsic activity of GLUT4 rather than insulin signaling.

The relationships among fluoride, cariogenic oral flora, and salivary flow rate during radiation therapy

Changes in the quantity of Streptococcus mutans, Lactobacillus species, and yeast Candida species were assessed in a cancer population undergoing head and neck radiation. The purpose of this study was to evaluate the effectiveness of a custom vinyl tray-applied fluoride gel to control cariogenic bacteria in a group experiencing hyposalivation because of radiation treatment. Twenty-two subjects participated in the study and served as their own controls. Whole resting and whole stimulated saliva were collected at weekly appointments beginning 1 week before and concluding 4 weeks after radiation therapy. Colony-forming units per mL of Streptococcus mutans and Lactobacillus species and semiquantitative counts of Candida species (0 = none; 1 = light; 2 = moderate; 3 = heavy) were determined from collected saliva. All patients were provided with custom vinyl vacuform mouthguards to be used daily with neutral fluoride gel (1.1% sodium fluoride). Whole stimulated and resting saliva productions decreased by 36.67% and 47.9%, respectively, by the end of 1 week of radiation therapy, and they remained low. No significant changes in cariogenic oral flora were seen during and early after radiation therapy, despite xerostomia. However, colonization by Candida albicans increased during radiation therapy for oropharyngeal cancers. Findings from this study suggest that changes in cariogenic flora may be suppressed through the use of daily topical neutral sodium fluoride gels and that colonization by Candida albicans increase during radiation therapy.

Periodontal attachment loss in patients after head and neck radiation therapy

OBJECTIVE

The purpose of this study was to determine the potential impact of head and neck radiation therapy on the progression of periodontal attachment loss.

STUDY DESIGN

Ten patients who received unilateral radiation fields that included the dentition were assessed before radiation treatment and after irradiation at a mean age of 6.01 years. Complete oral, dental, and periodontal examinations were completed by one examiner. The results were assessed through use of paired t tests.

RESULTS

More teeth were extracted because of periodontal disease in the field of radiation after irradiation. Remaining teeth in the radiated volume showed an increase in probing depth of 0.82 mm in comparison with 0.40 mm for teeth in the nonradiated region (P = .05). Recession on the facial aspects was 1.88 mm for teeth in the radiated volume and 1.16 mm for teeth in the nonradiated region (P = .001), and recession on the lingual aspects was 2.10 for teeth in the radiated volume and 0.91 for teeth in the nonradiated region (P = .05). Mean total attachment loss was 2.81 mm for teeth in the radiated sites; this compared with 1.43 mm for teeth in the nonradiated sites (P = .003). Increased mobility of teeth in the high-dose fields was seen (P = .02).

CONCLUSIONS

This study showed that tooth loss and greater periodontal attachment loss occur in teeth that are included within high-dose radiated sites of patients treated with irradiation therapy for cancer. These findings should be considered in preradiation treatment planning.

Prophylaxis of candidiasis in patients with leukemia and bone marrow transplants

OBJECTIVES

The increased risk for systemic fungal infection and the potential fatal consequences of disseminated candidiasis in bone marrow transplant patients has prompted study of prophylaxis and early treatment of candida colonization and infection.

STUDY DESIGN

Patients with leukemia who received fluconazole prophylaxis were compared with a concurrent group of patients not given prophylaxis for fungal organisms.

RESULTS

A trend to reduction of oropharyngeal colonization by Candida albicans was seen (p = 0.07) although no significant differences in systemic candidiasis were seen. In patients with documented systemic candidiasis, oral colonization was present and systemic infection was identified after the development of ulcerative oral mucositis.

CONCLUSIONS

Our results support the potential of fluconazole to reduce oropharyngeal colonization by Candida albicans, however, we did not show prophylaxis of oral candidiasis or systemic candidiasis. These findings and reports of fluconazole-resistant candidal species and a rising number of cases of infection as a result of Candida krusei indicate the need for further studies of prophylaxis of candidal infection in patients who are anticipated to develop profound neutropenia.

Hodgkin’s lymphoma in Chinese migrants to British Columbia:a 25-year survey

BACKGROUND

Compared with the West, Hodgkin's lymphoma in Oriental countries is characterized by a lower incidence rate and a higher proportion of mixed cellularity histology. Both environmental and genetic factors may be involved.

PATIENTS AND METHODS

The incidence and pattern of pathology of Hodgkin's lymphoma in the migrant Chinese population (0.4 million) in British Columbia (population 3.2 million) were studied. From a computerized database, all Hodgkin's lymphoma cases diagnosed in British Columbia from 1970 to 1997 were identified. Chinese descent was determined using patient surname by standard methodology and verified from the treatment record or by patient interview. The corresponding figures from the Chinese population in Hong Kong were used for comparison. For incidence rates, the age-specific incidence of Hodgkin's lymphoma in Hong Kong was obtained from the government cancer registry. For comparison of histology subtypes, 200 Hodgkin's lymphoma records from a Hong Kong regional referral center for the same time period were reviewed. Crude and age-standardized incidence rates were calculated by 5-year intervals in terms of age and calendar year, and relative rates were compared between the three populations.

RESULTS

From 1970 to 1997, Hodgkin's lymphoma was diagnosed in 34 Chinese patients in BC, with 24 cases diagnosed from 1970 to 1994. Thus, the crude and age-adjusted incidence rates from 1970 to 1994 were 0.91 and 1.14 per 100,000 per year in the British Columbia Chinese migrant population. Within the same period, 1862 cases of Hodgkin's lymphoma were diagnosed in British Columbia, giving a provincial background crude and age-adjusted incidence rates of 5.2 and 4.87 per 100,000 per year. The number of cases in the Hong Kong Chinese population (1970-1994) was 404, giving crude and age-adjusted incidence rates of 0.32 and 0.31 per 100,000 per year, respectively. Corrected for age and calendar year trends, the observed 25-year incidence of Hodgkin's lymphoma in British Columbia Chinese was significantly lower than expected from the British Columbia background population [24 observed versus 71 expected cases; standardized incidence ratio (SIR) = 0.34; 90% confidence interval (CI) 0.24-0.48; P <0.0001]. On the other hand, it is higher than that expected by extrapolating from the Hong Kong Chinese population (24 observed versus 8.5 expected cases; SIR = 2.81; 90% CI 1.94-3.95; P <0.0001). The difference is mainly accounted for by young patients with nodular sclerosis type disease in the migrant population.

CONCLUSIONS

Although any conclusion about the impact of migration on Hodgkin's lymphoma incidence and types in the Chinese population must be considered tentative due to the small number of observed cases and confounding variables such as age, changing diagnostic standards and secular trends in Hodgkin's lymphoma rates, our data demonstrate a tendency for the Chinese population of British Columbia to take on a Western pattern of Hodgkin's lymphoma. This observation provides additional evidence that both genetic and environmental influences play a role in the pathogenesis of this lymphoma, and that environmental factors can exert their influence over a relatively short period of time.

Myocardial protection by isoflurane vs. sevoflurane in ultra-fast-track anaesthesia for off-pump aortocoronary bypass grafting

BACKGROUND AND OBJECTIVES

Volatile anaesthetics have gained more popularity recently due to the potential for cardiac protection. Ultra-fast-track anaesthesia implies the immediate extubation after cardiac surgery. The purpose of this prospective randomized double-blind controlled study is to compare the cardioprotective effects of sevoflurane and isoflurane in off-pump cardiac bypass surgery.

METHODS

Forty patients undergoing elective off-pump cardiac bypass surgery with high thoracic epidural analgesia and immediate extubation at the end of surgery were randomized into two groups. During surgery, anaesthesia was provided with either 1 minimum alvelolar anaesthetic concentration of sevoflurane or 1 minimum alvelolar anaesthetic concentration of isoflurane. Troponin-T, creatine kinase-MB, left ventricular wall motion anomalies, time to extubation, respiratory functions and haemodynamic parameters were compared between the two groups by analysis of variance.

RESULTS

All patients were successfully extubated in the operating theatre with minimal postoperative pain. Serial creatine kinase-MB and troponin-T concentrations were not significantly different between the two volatile agents. Haemodynamic stability throughout surgery and contractility was not different between groups. However, extubation time was significantly shorter with sevoflurane (10 +/- 5 min) compared to isoflurane (18 +/- 4 min).

CONCLUSION

This study indicates that during off-pump cardiac bypass surgery, sevoflurane and isoflurane provide the same ischaemic cardioprotective effects. There is no difference for heart contractility and haemodynamic values during and after off-pump cardiac bypass surgery between the two agents. Sevoflurane allows a more rapid recovery from anaesthesia, but this does not translate into better pulmonary function or haemodynamics. Both agents are similar in ultra-fast-track off-pump cardiac bypass surgery.

Hepatitis C infection and B-cell non-Hodgkin's lymphoma in British Columbia: a cross-sectional analysis

OBJECTIVES

To determine the prevalence of hepatitis C virus (HCV) infection in patients with B-cell non-Hodgkin's lymphoma (NHL) in British Columbia.

DESIGN

A cross-sectional analysis.

SETTING

The British Columbia Cancer Agency (BCCA), a Canadian provincial tertiary oncology referral center.

SUBJECTS

Consecutive patients with B-cell NHL registered onto the BCCA lymphoma database in 1996 and part of 1997 and a control group of patients with T-cell NHL registered on the database from 1995 through 1997. Patients with HIV infection were excluded from the analysis. A second control group (n = 1085) consisted of health-care workers tested for HCV infection following a needle-stick injury.

INTERVENTIONS

Stored sera from patients with B-cell NHL (n = 88) and T-cell NHL (n = 37), identified from the database, were tested for the presence of HCV infection with commercially available serologic tests.

MAIN OUTCOME MEASURES

HCV seropositivity in the B-cell lymphoma group compared to the control groups (T-cell NHL and health-care workers).

RESULTS

2.3% of the B-cell NHL group, none of the T-cell NHL group and 1% of the health-care worker control group were positive for HCV infection. These results were not statistically significantly different.

CONCLUSION

Patients in British Columbia with B-cell NHL do not have an increased prevalence of HCV infection. These data suggest that the lymphotrophism of HCV may differ by regional, racial and genotypic variations around the world.

Assessment of epidermal growth factor in oral secretions of patients receiving radiation therapy for cancer

Biological response modifiers have been studied in animal models of oral mucositis. We assessed the presence of epidermal growth factor (EGF) in patients during radiation therapy for head and neck cancer. The findings of this preliminary study showed that it is possible to measure the presence of EGF in oral secretions during radiation therapy. EGF was shown to decrease during the course of radiation therapy, and a trend was seen with decreasing EGF and increasing oral ulceration (P = 0.10) and increasing total mucositis score (P = 0.09).

Incidence of second neoplasms in patients with MALT lymphoma: no increase in risk above the background population

BACKGROUND

Lymphomas of mucosa associated lymphoid tissue (MALT) are a special type of extranodal lymphoma, possibly related to chronic antigenic stimulation. Increased cancer susceptibility may also contribute to the development of MALT lymphoma (MALToma). It has been suggested that patients with MALToma have an increased incidence of other malignancies.

PATIENTS AND METHODS

We retrospectively reviewed the histology and clinical records of 147 patients with MALToma, including 51 cases of gastric MALToma. The incidence of any second malignancy was confirmed with a provincial registry. The relative rates of cancer, excluding MALToma, were calculated relative to the background population of the same age group and secular year.

RESULTS

A total of 41 tumors occurred in 32 patients (21%), including 22 solid tumors. The incidence of solid tumors in the gastric MALToma group was 15%. Seven patients had two or more second malignancies. Cancer occurred before diagnosis of MALToma in 29 cases, concurrent with MALToma in three, and after MALToma in nine. Follow-up of the surviving patients is short (median 17.6 months). The relative rate from birth of a second malignancy was 0.86 in the whole group (90% confidence interval (CI): 0.62-1.16) and 0.95 (90% CI: 0.55-1.54) in the gastric MALToma group. The rates were roughly the same if skin cancers were excluded.

CONCLUSIONS

The incidence of second cancers in this series is similar to previous reports. However, when compared to an age-matched population followed for the same period of time, MALToma patients do not appear to have a statistically significant increased rate of cancers.

Disabled is a putative adaptor protein that functions during signaling by the sevenless receptor tyrosine kinase

DRK, the Drosophila homolog of the SH2-SH3 domain adaptor protein Grb2, is required during signaling by the sevenless receptor tyrosine kinase (SEV). One role of DRK is to provide a link between activated SEV and the Ras1 activator SOS. We have investigated the possibility that DRK performs other functions by identifying additional DRK-binding proteins. We show that the phosphotyrosine-binding (PTB) domain-containing protein Disabled (DAB) binds to the DRK SH3 domains. DAB is expressed in the ommatidial clusters, and loss of DAB function disrupts ommatidial development. Moreover, reduction of DAB function attenuates signaling by a constitutively activated SEV. Our biochemical analysis suggests that DAB binds SEV directly via its PTB domain, becomes tyrosine phosphorylated upon SEV activation, and then serves as an adaptor protein for SH2 domain-containing proteins. Taken together, these results indicate that DAB is a novel component of the SEV signaling pathway.

Substrate recognition by amyloglucosidase: evaluation of conformationally biased isomaltosides

Amyloglucosidase catalyzes the hydrolysis of methyl beta-maltoside (1) 30-50 times more rapidly than methyl alpha-isomaltoside (2). It is established that OH-6', OH-4', and OH-4 which are involved in key polar interactions with the enzyme in the case of isomaltoside. Conformational analyses based on HSEA calculations indicate that the dispositions in space of OH-3 of maltose relative to OH-4' and OH-6' in the preferred conformation for the maltoside (1) is energetically more readily achieved by methyl 6R-C-methyl-alpha-isomaltoside (3), than for its 6-S-isomer (4). A kinetic evaluation of the hydrolysis in fact has shown that the R-compound is more strongly bound by the enzyme (Km = 0.9 mM) than the parent isomaltoside (Km = 24.5 mM), whereas the S-compound has the weakest enzyme binding (Km = 90 mM). Since the kcat values were all within the range 0.85 +/- 0.20 s-1, it is evident that the relative rates of hydrolysis are related to the relative ease for the compounds to achieve an interaction of a hydroxyl group in the aglycon of an alpha-D-glucopyranoside with the enzyme for the formation of the enzyme-substrate complex. The relative rates of hydrolysis of the alpha-glucosides of the 1,3-dihydroxy-trans-decalins, 5 and 6, provide further support for this highly desirable but not necessary recognition for the orientation of the reducing glucose unit in the active site.

Application of the World Health Organization system for HIV infection in a cohort of homosexual men in developing a prognostically meaningful staging system

OBJECTIVE

Validation of a modified version of the recently proposed World Health Organization (WHO) staging system for HIV infection and disease in a cohort of homosexual men.

METHODS

Five hundred and thirty HIV-positive men followed for a median of 51 months (range, 1-98 months) were eligible for analysis. Subjects were classified into stages at their first seropositive visit and at all subsequent visits.

RESULTS

As of 1 April 1991, 136 subjects (26%) had progressed to stage IV of the modified WHO system on the basis of their CD4 lymphocyte counts, and 78 subjects (15%) had died. Kaplan-Meier estimates for progression to stage IV from stages I, II and III were 52.8 +/- 7.5% over 6.6 years, 58.1 +/- 7.1% over 5.9 years and 66.5 +/- 9.7% over 5.7 years (log-rank P = 0.0001). Estimated median times to stage IV were 6.4, 5.3 and 3.8 years from stages I, II and III, respectively. Estimated median times to death were 10.9, 8.2, 6.3 and 1.7 years from stages I to IV, respectively. Results remained unchanged when CD4 lymphocyte count was replaced with lymphocyte count in the laboratory axis of the staging system.

CONCLUSIONS

The proposed staging scheme, based on the WHO system, provides a prognostically meaningful classification for HIV infection in a cohort of homosexual men. Furthermore, the use of absolute lymphocyte count as a valid alternative for CD4 lymphocyte count has implications for the applicability of this system in many parts of the world where diagnostic resources are limited.

A long, nontranslatable poly(A) RNA stored in the egg of the sea urchin Strongylocentrotus purpuratus

Nontranslatable transcripts containing interspersed repetitive sequence elements constitute a major fraction of the poly(A) RNA stored in the cytoplasm of both the sea urchin egg and the amphibian oocyte. We report the first complete sequence of a representative interspersed maternal RNA transcript, called ISp1. The transcript is about 3.7 kb in length [including poly(A) tail]; and the 5' half consists of a cluster of repetitive sequences, whereas the 3' half is single copy. Other repetitive sequences occur in the 5' and 3' regions flanking the transcription unit. In several cloned alleles, the flanking repetitive and single-copy sequences differ, indicating a high degree of insertional and deletional rearrangement around, as well as within, the transcription unit. No significant open reading frames exist in any region of the ISp1 transcript, nor is it spliced to give rise to translatable mRNA in egg or embryo. A 620-nucleotide repetitive sequence element at the 5' end of the ISp1 transcript is also represented in a large number of other long interspersed maternal poly(A) RNAs. In addition, this sequence appears in a prevalent set of small polyadenylated RNAs about 600-nucleotides in length, which disappear almost completely by the gastrula stage of development. The structural features of the ISp1 RNA uncovered in this work exclude several hypotheses of interspersed maternal poly(A) RNA origin and function.

Pretreatment assessment and dental management of patients with nasopharyngeal carcinoma

Patients who present with nasopharyngeal carcinoma (NPC) require through oral and dental assessment prior to treatment of the malignancy. We assessed the oral status of 57 consecutive patients with a diagnosis of NPC. In this study, identified risk factors for NPC were seen to be different in Asian versus non-Asian patients. Epstein-Barr virus seropositivity was seen in all Asian patients and in 69% of non-Asian patients (P = 0.00006), and reported alcohol use was greater in the non-Asian patients. In this study it was found that 68% of dentate patients required dental extractions primarily due to periodontal disease. Even in patients who reported receiving regular dental care (28%) extractions prior to radiation therapy were suggested. Oral complications of radiation therapy were reported by 84% of patients, with the most common being xerostomia. Clinical diagnosis of candidiasis (16%), rampant caries (10% of dentate patients) and difficulties with dentures (25% of denture wearers) were noted. In addition to pretreatment assessment, continuing oral and dental management is needed for patients with NPC.

Chemical modification to reduce renal uptake of disulfide-bonded variable region fragment of anti-Tac monoclonal antibody labeled with 99mTc

The anti-Tac disulfide-bonded variable region fragment (dsFv) is a genetically engineered, 25 kDa, murine monoclonal antibody fragment that recognizes the alpha subunit of the interleukin-2 receptor (IL-2Ralpha). The dsFv radiolabeled with the tetrafluorophenyl ester (TFP) of [99mTc]mercaptoacetyltriglycine ([99mTc]MAG3-TFP) showed rapid tumor uptake and fast blood clearance in mice, resulting in high tumor-to-nontumor background ratios. However, its high renal uptake was a problem. In this study, we tested the effect of lowering the isoelectric point (pI) of dsFv to <9.3 on renal and tumor uptake. To lower the pI, dsFv was acylated simultaneously with both [99mTc]MAG3-TFP and TFP-glycolate. The acylation of dsFv decreased its pI and its immunoreactivity inversely proportional to the molar ratio of TFP-glycolate to dsFv, whereas the conjugation of [99mTc]MAG3-TFP alone did not. When biodistribution studies were performed in nude mice, the effect of the lowered pI was reflected primarily in decreased kidney uptake and whole-body retention, with its highest effect seen at the earliest time point (15 min) after injection. In tumor-bearing nude mice, glycolated [99mTc]MAG3-dsFv with a pI range of 4.9 to 6.5 accumulated selectively into IL-2 receptor-positive SP2/Tac tumor similar to that of the control [125I]dsFv labeled by the Iodo-Gen method, whereas its renal uptake was 25% of [125I]dsFv at 15 min. At 90 min, the ratios of tumor to receptor-negative SP2/0 tumor, liver, kidney, stomach, and blood had peaked at 10.9, 8.5, 0.3, 5.0, and 6.2, respectively, for the glycolated [99mTc]MAG3-dsFv. The corresponding ratios for [125I]dsFv were 3.7, 5.0, 0.1, 1.5, and 2.1, respectively.

Advanced diffuse large-cell lymphoma treated with 12-week combination chemotherapy: natural history of relapse after initial complete response and prognostic variables defining outcome after relapse

PURPOSE

To define both the natural history of and prognostic factors affecting outcome post relapse from a complete response in advanced stage diffuse large-cell lymphoma.

PATIENTS AND METHODS

A total of 468 patients aged 17-74 years received the 12-week duration chemotherapy regimens MACOP-B, VACOP-B and ACOP-12 between 1 April 1981 and 31 December 1995 for advanced stage diffuse large, mixed or immunoblastic lymphoma. Of these 402 entered a complete remission, 97 (24%) of whom subsequently relapsed. Initial staging data, follow-up, and relapse information were analyzed to define the natural history of relapse and also subjected to univariate and multivariate correlation with overall (OS) and failure free survival (FFS).

RESULTS

Eleven percent of the relapses were low grade. All other relapses were of intermediate grade with 75% occurring within the first two years, the remainder up until the eleventh year. Median and five-year OS from the time of relapse for intermediate grade relapse were 12 months and 20%; for FFS they were eight months and 18% respectively. Adverse independent factors, for both OS and FFS were: less than one year to relapse, decreasing performance status at relapse, and more than three nodal sites at relapse.

CONCLUSIONS

Low-grade relapse is not uncommon in patients who initially presented with diffuse large cell lymphoma. As the management of low- and intermediate grade disease is so different biopsy proof of the nature of the relapse is of value. The prognostic factors identified need to be taken into consideration when analyzing results from trials of secondary treatment so as to avoid erroneous conclusions about comparative treatment efficacy.

An improved synthesis of [125I]N-(diethylaminoethyl)-4-iodobenzamide: a potential ligand for imaging malignant melanoma

To improve the radiolabeling yield and the specific activity of [125I]N-(2-diethylaminoethyl)-4-iodobenzamide (DAB), the aryltributyltin precursor was synthesized from the N-(2-diethylaminoethyl)-4-bromobenzamide derivative by palladium catalyzed stannylation using bis(tributyltin). The radiolabeled product, [125I]DAB, was obtained by an iododestannylation reaction in high radiochemical yields (85-94%, radiochemical purity, > 98%) using chloramine-T as an oxidizing agent. The specific activity was greater than 1600 Ci/mmol. The biodistribution studies in nude mice implanted with human malignant melanoma xenograft showed a good tumor uptake (6.14% ID/g at 1 h, 2.81% ID/g at 6 h and 0.42% ID/g at 24 h) of [125I]DAB. Unfortunately, a high uptake in the non-target organs, such as liver and lung, was found. At 1 h post-injection the activity level in liver and lung was 11.76 and 7.58% ID/g, respectively. A slow clearance of activity from liver and lung was observed at 6 h (3.43 and 0.49% ID/g). These results demonstrate that iodinated IDAB is a potential radiopharmaceutical for the management of patients with malignant melanoma.