Multicentre study of abdominal aortic aneurysm measurement and enlargement

Background

No effective treatment is currently available to prevent progression of small and medium-sized abdominal aortic aneurysms (AAAs). Identification of drugs with sufficient promise to justify large expensive randomized trials remains challenging. One potentially useful strategy is to look for associations between commonly used drugs and AAA enlargement in appropriately adjusted observational studies.

Methods

Potential AAA measurements were identified from abdominal imaging reports in the electronic data files of three medical centres from 1995 to 2010. AAA measurements were extracted manually and patients with an aneurysm of 3 cm or larger, who had at least two measurements over an interval of at least 6 months, were identified. Other data were obtained from the electronic data files (demographics, co-morbidities, smoking status, drug use) to conduct a propensity analysis of the associations of drugs and other factors with AAA enlargement.

Results

From 52 962 abdominal imaging studies, 5362 patients with an AAA of 3 cm or more were identified, of whom 2428 had at least two measurements over at least 6 months. Mean AAA follow-up was 3·4 years and the mean AAA enlargement rate was 2·0 mm per year. Propensity analysis demonstrated no significant association of AAA enlargement with statins, beta-blockers, angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. Diabetes was associated with a reduction in AAA enlargement of 1·2 mm per year (P = 0·008), and chronic obstructive pulmonary disease was associated with increased enlargement (0·5 mm per year; P = 0·050). Moderate AAA measurement variation and substantial terminal digit preference were also observed, but the digit preference became less pronounced after 2000.

Conclusion

This study confirms the negative association of diabetes with AAA progression. There was no evidence that commonly used cardiovascular drugs affect AAA enlargement.

Improved survival after acute myocardial infarction in patients with advanced Killip class

BACKGROUND

The continuing applicability of the Killip classification system to the effective stratification of long-term and short-term outcome in patients with acute myocardial infarction (MI) and its influence on treatment strategy calls for reanalysis in the setting of today's primary reperfusion treatments.

HYPOTHESIS

Our study sought to test the hypothesis that Killip classification, established on admission in patients with acute MI, is an effective tool for early prediction of in-hospital mortality and long-term survival.

METHODS

A series of 909 consecutive Olmsted County patients admitted with acute MI to St. Marys Hospital, Mayo Clinic, between January 1988 and March 1998 was analyzed. Killip classification was the primary variable. Endpoints were in-hospital death, major in-hospital complications, and post-hospital death.

RESULTS

Patients analyzed included 714 classified as Killip I, 170 classified as Killip II/III, and 25 classified as Killip IV. Increases in in-hospital mortality and prevalence of in-hospital complications correspond significantly with advanced Killip class (p < 0.01), with in-hospital mortality 7% in class I, 17.6% in classes II/III, and 36% in class IV patients (p < 0.001). Killip classification was strongly associated with mode of therapy administered within 24 h of admission (p < 0.01). Killip IV patients underwent primary angioplasty most commonly and were less likely to receive medical therapy.

CONCLUSIONS

Killip classification remains a strong independent predictor of in-hospital mortality and complications, and of long-term survival. Early primary angioplasty has contributed to a decrease in mortality in Killip IV patients, but effective adjunctive medical therapy is underutilized.

Obesity is associated with premature occurrence of acute myocardial infarction

BACKGROUND

The American Heart Association has classified obesity as a major modifiable risk factor for coronary artery disease, but its relationship with age at presentation with acute myocardial infarction (AMI) is poorly documented.

HYPOTHESIS

The study was undertaken to evaluate the impact of obesity on age at presentation, and on in-hospital morbidity and mortality in patients with AMI.

METHODS

Our analysis includes a consecutive series of 906 Olmsted County patients (mean age 67.7 years, 51% male) admitted with AMI to the Mayo Clinic Coronary Care Unit (CCU). The patients were entered into the Mayo CCU Database, a prospective registry of data pertaining to patients admitted to the Mayo Clinic CCU with AMI. Age at AMI occurrence and in-hospital morbidity and mortality were noted.

RESULTS

Obese patients (body mass index [BMI] >30) with AMI were significantly younger than patients with AMI in the overweight (BMI 25-30) and normal-weight (BMI < 30) groups (62.3+/-13.1 vs. 66.9+/-13.2 and 72.9+/-13.4, respectively. p < 0.001). Obesity and overweight status were associated with male gender, diabetes mellitus, hypercholesterolemia, and smoking history; however, after multivariate adjustment for these risk factors, excess weight and premature AMI remained significantly associated. Compared with normal-weight patients, overweight patients presenting with AMI were 3.6 years younger (p < 0.001, confidence interval [CI] 1.9-5.4) and obese patients 8.2 years younger (p < 0.001, Cl 6.2-10.1). No significant increase in in-hospital morbidity and mortality was seen.

CONCLUSION

In this population-based study, overweight and obese status are independently associated with the premature occurrence of AMI, but not with an increased incidence of in-hospital complications.

Reliability of self-reported willingness-to-pay and annual income in patients treated for toenail onychomycosis

BACKGROUND

Willingness-to-pay (WTP) is a health economics measure that has recently been used for skin diseases to evaluate patients' quality of life. However, the reliability of this measure has not been investigated in the dermatology literature and is essential in validating its use in health services research.

OBJECTIVES

This study evaluated the test-retest reliability of self-reported annual income and WTP, a health economics measure of disease impact, in patients with toenail onychomycosis.

METHODS

Forty-six patients enrolled in a randomized clinical trial comparing two different dosing regimens of terbinafine completed a self-administered questionnaire at baseline and 1 month later. The questionnaire asked: (i) how much patients would be willing to pay for a theoretical treatment with a cure rate of 85% for their current onychomycosis (10 categories: $0-50, $51-100, to > $800); and (ii) annual income (10 categories: $0-10,000 to > $200,000).

RESULTS

Forty-four patients reported WTP at both visits, and 55% reported the same WTP. The quadratic-weighted (Fleiss-Cohen) kappa statistic indicated moderate agreement (kappa = 0.50, 95% confidence interval, CI 0.24-0.75, P < 0.01) as did the Spearman rank-order correlation coefficient (r(s) = 0.57, P < 0.01; median difference = 0, P = 0.50). Strong agreement was shown among the 42 patients who reported income at both visits; 71% reported the same annual income category (kappa = 0.72, 95% CI 0.47-0.96, P < 0.01; r(s) = 0.68, P < 0.01; median difference = 0, P = 0.77). Age, disease severity and duration, previous therapy, self-reported annual income, and medication side-effects were not statistically associated with the reliability of WTP.

CONCLUSIONS

WTP and annual income demonstrated moderate and strong test-retest reliability, respectively. Self-reported WTP can serve as a reliable measure for future health economics research on onychomycosis.

Fermentation of chicory fructo-oligosaccharides in mixtures of different degrees of polymerization by three strains of bifidobacteria

We estimated and compared the action of three selected strains of bifidobacteria in a semi-synthetic medium for different degrees of polymerization of fructo-oligosaccharides contained in three commercial products derived from chicory inulin: Fibrulose F97 (shorter chains), Fibruline Instant (native chains), Fibruline LC (longer chains). Biomass and production of lactate and acetate were greater when the substrate contained mostly shorter chain fructo-oligosaccharides. Shorter chains were first to be consumed, and one strain could use longer chains. As the degree of polymerization increased, residual fructo-oligosaccharides increased after growth of the strains, and the rate of consumption of fructo-oligosaccharides decreased.

Fermentations of fructo-oligosaccharides and their components by Bifidobacterium infantis ATCC 15697 on batch culture in semi-synthetic medium

AIMS

To compare the physiological behaviour of Bifidobacterium infantis ATCC 15697 growing on synthetic oligofructose or its components.

METHODS AND RESULTS

The studies were carried out in regulated or non-regulated batch cultures on semi-synthetic media. Differences between the carbohydrate utilization patterns with glucose, fructose, sucrose and fructo-oligosaccharides (FOS) were determined. Glucose was the preferred substrate for growth and biomass production, whereas fructose was the best for lactate and acetate production. With sucrose, biomass production reached the level obtained with glucose, whereas with FOS, more metabolites were produced, as with fructose. In a mixture of FOS, the shorter saccharides were used first and fructose was released in the medium. Fructofuranosidase, an enzyme necessary to hydrolyse FOS, was inducible by fructose.

CONCLUSION

Glucose contained in FOS and sucrose might sustain growth and cell production, while fructose might enable the production of major metabolites.

SIGNIFICANCE AND IMPACT OF THE STUDY

A better understanding of the bifidogenic nature of oligofructose has been gained.

Length of stay in myocardial infarction

OBJECTIVE

We evaluated the association between length of hospital stay (LOS) and clinical factors, treatment intensity, and use of percutaneous coronary revascularization from 1988 to 1997.

BACKGROUND

Multiple factors contribute to the observed reduction in LOS for patients with myocardial infarction.

METHODS

We studied a series of 849 consecutive patients admitted with acute myocardial infarction to the Mayo Clinic Coronary Care Unit within three time periods: period I (1988-1990), period II (1991-1993), and period III (1994-1997).

RESULTS

Median LOS decreased significantly between 1988 and 1997 (9 days to 5 days, 36% reduction, p < 0.0001), with significant reductions (p < 0.001) associated with certain therapies: primary reperfusion (6 days vs 7 days), b-blockers (6 days vs 8 days), and aspirin (6 days vs 8 days). Hospitalizations were lengthened by coronary artery bypass grafting (12 vs 6 days) and by serious complications (10 vs 6 days). The era of the admission (period I vs II vs III) is a significant, powerful predictor of LOS, even after adjustment for other key variables.

CONCLUSION

The 36% reduction in LOS for acute myocardial infarction between 1988 and 1997 is related both to therapeutic modalities and temporal trends. Further study is needed to clarify whether the trend for decreasing LOS persists and influences outcome and health care quality variables.

Bile salt toxicity to some bifidobacteria strains: role of conjugated bile salt hydrolase and pH

The purpose of this work was to study some aspects of bile salt toxicity towards bifidobacteria. A strain (Bifidobacterium coryneforme ATCC 25911) was selected for its lack of conjugated bile salt hydrolase activity (CBSH-), and was used with three deconjugating strains (CBSH+), for study of their growth and viability in the presence of two dihydroxylated conjugated bile salts (tauro- and glyco-deoxycholic acids). The presence of the glycoconjugate induced a more significant growth inhibition for the four strains than the tauroconjugate. The viability of the strains was measured at several pH levels. Glycodeoxycholic acid, but not taurodeoxycholic acid, exerted a lethal effect, which increased at low pH. This phenomenon was more pronounced for the CBSH- strain. We explain some of these results using an hypothesis based on the consequence of dissociation of conjugated and deconjugated bile salts, and the value of their pKa.

Isolation and characterization of a Lactobacillus amylovorus mutant depleted in conjugated bile salt hydrolase activity: relation between activity and bile salt resistance

Growth experiments were conducted on Lactobacillus amylovorus DN-112 053 in batch culture, with or without pH regulation. Conjugated bile salt hydrolase (CBSH) activity was examined as a function of culture growth. The CBSH activity increased during growth but its course depended on bile salts type and culture conditions. A Lact. amylovorus mutant was isolated from the wild-type strain of Lact. amylovorus DN-112 053 after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. An agar plate assay was used to detect mutants without CBSH activity. In resting cell experiments, the strain showed reduced activity. Differences between growth parameters determined for wild-type and mutant strains were not detected. Comparative native gel electrophoresis followed by CBSH activity staining demonstrated the loss of proteins harbouring this activity in the mutant. Four protein bands corresponding to CBSH were observed in the wild-type strain but only one was detected in the mutant. The specific growth rate of the mutant strain was affected more by bile salts than the wild-type strain. Nevertheless, bile was more toxic for the wild-type strain. In viability studies in the presence of nutrients, it was demonstrated that glycodeoxycholic acid exerted a higher toxicity than taurodeoxycholic acid in a pH-dependent manner. No difference was apparent between the two strains. In the absence of nutrients, the wild-type strain died after 2 h whereas no effect was observed for the mutant. The de-energization experiments performed using the ionophores nigericin and valinomycin suggested that the chemical potential of protons (ZDeltapH) was involved in Lactobacillus bile salt resistance.

Effects of Lactobacillus amylovorus and Bifidobacterium breve on cholesterol

To determine the validity of the hypothesis of assimilation and/or precipitation of cholesterol by Lactobacillus and Bifidobacterium species, culture were undertaken in TPY medium containing oxgall or taurocholic acid. In the case of growing cells, both strains were able to remove cholesterol in the presence of bile salts. Nevertheless, the behaviour was different according to the kind of bile salt. In the presence of taurocholic acid, the removal of cholesterol was due to both bacterial uptake and precipitation. In the presence of Oxgall, bacterial uptake and precipitation were observed for Lactobacillus but only precipitation occurred for Bifidobacterium.

Effects of fructooligosaccharides and their monomeric components on bile salt resistance in three species of bifidobacteria

The influence of fructooligosaccharides (FOS) and their monomeric components on bile salt resistance of Bifidobacterium breve ATCC 15700, Bif. longum ATCC 15707 and Bif. animalis ATCC 25527 was examined. The neosugars induced fructofuranosidase activities for the degradation of these saccharides. For the three strains tested the growth was identical and bile salts had the same inhibitory effect on growth whatever the carbohydrate used. The survival of Bif. breve and Bif. longum, in the presence of glycodeoxycholic acid depended, however, on carbohydrates: the toxic effects of the bile salt could be partly alleviated by the addition of a metabolizable C-source. For Bif. animalis, the presence of any carbohydrate in the incubation medium did not enhance the viability of the strain. But in the three deconjugating strains of bifidobacteria studied, the presence of neosugar during the growth led to improved resistance to the bactericidal effect of the bile salt compared with the monomeric components of these neosugars (glucose and fructose).

A randomized phase II trial of two schedules of topotecan for the treatment of advanced stage non-small cell lung cancer

We conducted a randomized phase II trial of two different schedules of topotecan in patients with advanced-stage non small lung cancer (NSCLC) without prior cytotoxic chemotherapy. All patients had histologic or cytologic confirmation of stage IV (M1) or III-B NSCLC. Patients were stratified by performance status, stage and weight loss. Patients were randomized to receive topotecan at intravenous doses of 1.5 mg/m(2)/day over 30 min for 5 days every 3 weeks (Arm A) or 1.3 mg/m(2)grade 3 in both arms included leukopenia, thrombocytopenia, malaise, constipation, diarrhea, lethargy, pulmonary, vomiting, infection and myalgia. Severe (> or = grade 3) thrombocytopenia occurred in 15.8% of Arm A patients and 37.8% of Arm B patients and this difference was statistically significant (P=0.03). The median times to progression are 101 and 63 days (P=0. 75) and the median survival times are 257 and 179 days (P=0.83) for Arms A and B, respectively. These differences in time to progression and overall survival are not statistically significant. Topotecan has limited, single agent activity in advanced NSCLC when given as 1. 5 mg/m(2)/day over 30 min for 5 days every 3 weeks. We do not intend to pursue further investigations with topotecan in patients with NSCLC.

Paclitaxel and G-CSF in previously untreated patients with extensive stage small-cell lung cancer: a phase II study of the North Central Cancer Treatment Group

Paclitaxel is an antimicrotubule agent that interferes with cell division. It has demonstrated promising single-agent activity against non-small-cell lung cancer. The purpose of this study was to evaluate the therapeutic effectiveness of paclitaxel in previously untreated patients with extensive stage small-cell lung cancer (SCLC). The study was designed as a two-stage phase II trial. All patients who entered received paclitaxel by intravenous infusion at a dose of 250 mg/m2 during 24 hours. Granulocyte colony stimulating factor was also provided to ameliorate neutropenia. Cycles were repeated at 21-day intervals. Patients who achieved a complete response received a maximum of 10 cycles of treatment, whereas those who achieved a partial response/regression continued treatment until progression or undue toxicity developed. Patients who progressed or maintained stable disease for six cycles were crossed over to cisplatin and etoposide. Forty-three patients entered the study and all were evaluable for analysis. Responses were observed in 23 (53%) of the patients. There was no significant difference in the response rates in patients with measurable or evaluable disease (13/23 versus 10/20, p = 0.76). At the time of analysis, 39 patients had progressed with a median time to progression of 95 days, and 39 patients had died with a median survival of 278 days. The 1-year achieved survival rate was 24%. Significant neutropenia (absolute neutrophil count <1,000/microl) occurred in 24 (56%) of the patients, but only 2 patients experienced severe infection (grade > or = 3), and there were no septic deaths. The results indicate that paclitaxel is active against SCLC. Myelosuppression was the main side effect in this patient population. Response duration was short (median = 3.4 months), which suggests that paclitaxel is not sufficient as a single agent. Further studies of paclitaxel in combination with other agents against SCLC are currently in progress within the North Central Cancer Treatment Group and other cancer treatment groups. Key Words: Paclitaxel-G-CSF-Small-cell lung cancer-North Central Cancer Treatment Group.

Cerebral toxicity in patients treated for small cell carcinoma of the lung

OBJECTIVE

To present the clinical characteristics of patients enrolled in a trial of treatment of small cell carcinoma (SCC) of the lung and to describe the central nervous system toxicity associated with the chemotherapy and prophylactic cranial irradiation (PCI).

MATERIAL AND METHODS

We performed a retrospective analysis of 60 patients with SCC who received chemotherapy and thoracic radiation therapy. PCI was administered to patients who had limited disease or who had extensive disease that was subsequently down-staged to only residual chest disease after initial treatment. The total PCI dose was 3,200 cGy administered in 16 fractions of 200 cGy, given concurrently with systemic chemotherapy. Diagnostic criteria for leukoencephalopathy were based on previously published guidelines.

RESULTS

Of the 60 eligible and enrolled patients, 35 received PCI and 25 did not. Leukoencephalopathy developed in 5 of the 35 patients (14%) who received PCI. The median age of the patients in whom leukoencephalopathy developed was 64 years (range, 57 to 69), and the median follow-up time was 59 months. The most common signs and symptoms of leukoencephalopathy were intellectual changes, memory alterations, and motor abnormalities. The mean time to onset of symptoms after termination of irradiation was 357 days (range, 30 to 524). Of all 60 patients, 6 were still alive 4 years after enrollment, and 3 of them (50%) already had leukoencephalopathy.

CONCLUSION

Small dosage fractions of PCI may still result in leukoencephalopathy. The routine use of PCI in the management of SCC should be reassessed because of increasing evidence of the toxicity associated with it.

Phase II study of high-dose somatostatin analogue in patients either previously treated or untreated who have extensive-stage small cell lung cancer

The authors conducted a phase II study of somatostatin analogue in 18 patients with extensive stage small cell lung cancer (four with previous treatment, 14 without previous treatment). Patients received 2,000 mg subcutaneously thrice daily. They were required to have an Eastern Cooperative Oncology Group performance score of 0-2 and acceptable pretreatment biochemical parameters. No patient responded to treatment. The median time to progression was 44 days. The median survival was 106 days. Toxicity related to treatment consisted of mild diarrhea and anorexia. Somatostatin analogue is not active as a single agent in the treatment of extensive-stage small cell lung cancer.

Postoperative localization of porta hepatis and abdominal vasculature in pancreatic malignancies: implications for postoperative radiotherapy planning

PURPOSE

To evaluate changes in preoperative and postoperative positions of structures used to define target volumes (i.e., pancreatic bed, porta hepatis, local-regional lymph nodes) for postoperative irradiation of pancreatic malignancies as defined by abdominal computed tomographs.

METHODS AND MATERIALS

Eleven consecutive patients who had Whipple resection and postoperative irradiation for pancreatic cancer were evaluated. Preoperative and postoperative computed tomographs of each patient were evaluated for the position of the portal vein bifurcation and the origin of the celiac axis and superior mesenteric artery. The length along the x (medial-lateral position) and y (anterior-posterior position) axes was determined with calipers to the closest millimeter. Length along the z axis (cephalad-caudad position) was determined with the computed tomographic sectional interval between images. Statistical significance of the change in the structure's position along the x, y, or z axis between preoperative and postoperative computed tomographs was assessed with the paired t-test.

RESULTS

Evaluation of the preoperative and postoperative positions of the portal vein, celiac axis, and superior mesenteric artery along the x, y, and z axes revealed a statistically significant change in the location of the portal vein and celiac axis postoperatively. The median change of the celiac axis in the anterior-posterior position was significant (p = 0.0047), but the mean change was only 2 mm and not considered clinically significant. The median change for the portal vein was 0.97 cm and 1.07 cm along the y and x axes, respectively, and was significant (p = 0.008 and p = 0.0001). The range in position change for the portal vein was 0.0 to 2.0 cm along the y axis and 0.4 to 1.9 along the x axis. The remaining mean changes in position along all axes for all the structures were less than 3 mm (not statistically significant).

CONCLUSIONS

The mean position of the portal vein-porta hepatis after Whipple resection is approximately 1.0 cm medial and 1.0 cm posterior compared with its preoperative position. These data suggest that postoperative abdominal computed tomographs are useful in determining treatment volumes of nodal drainage basins after Whipple resection of pancreatic malignancies.

Laryngeal chondrosarcomas: the Mayo Clinic experience

BACKGROUND

Laryngeal chondrosarcomas occur infrequently. Their management is often guided by inferences made from the management of sarcomas arising from more commonly afflicted organs.

METHOD

A retrospective analysis of patients with laryngeal chondrosarcomas treated at the Mayo Clinic between 1959 and 1992 was performed to assess prognostic factors and outcomes after various treatments.

RESULTS

A total of 20 patients received treatment during this time period. All chondrosarcomas were low grade; 19 involved the cricoid cartilage and one arose in the supraglottic larynx. Initial treatment consisted of local excision (often subtotal removal) alone in 12 patients (60%), hemilaryngectomy in 2 (10%), near total laryngectomy in 2 (10%), and total laryngectomy in 4 (20%). Six patients (30%) had local recurrence: five initially had local excision and one had hemilaryngectomy. All local recurrences or tumor progression developed >3 years after initial treatment. Salvage surgery was performed in five of the six patients who had local recurrence, and the other patient was observed. Of the five patients who had salvage surgery, three required another resection because of a second recurrence.

CONCLUSIONS

These results suggest that initial conservative subtotal laryngectomy should be explored further because this treatment may provide long-term voice preservation in most patients, and patients who experience a recurrence after local excision often have been given several years of voice preservation.

Can molgramostim enhance the antitumor effects of cytotoxic drugs in patients with advanced sarcomas?

BACKGROUND

A phase I study was designed for the amalgamation of two previously studied antisarcoma regimens (ifosfamide+doxorubicin and mitomycin+doxorubicin+cisplatin) supported by molgramostim. Thus, we hoped to develop a better regimen for the treatment of advanced sarcomas.

PATIENTS AND METHODS

Fifteen adult advanced sarcoma patients and six other patients were registered and sequentially assigned to receive three progressively more myelosuppressive levels of chemotherapy: level I-ifosfamide 2500 mg/m2 + doxorubicin 40 mg/m2 + cisplatin 60 mg/m2 all given on day 0, followed by molgramostim 5 micrograms/kg every 12 hours for 14 days; level II-exactly the same chemotherapy from level I given on day 1 preceded on day 0 by ifosfamide 2500 mg/m2 and an additional four days of molgramostim given on days-6 through-3; level III-same as level II except for the addition of mitomycin 4 mg/m2 immediately prior to cisplatin on day 1. MENSA 500 mg/m2 was given five times on each day that involved ifosfamide treatment. For all levels, treatment was repeated at four-week intervals.

RESULTS

Preliminary results and toxicity were reported three years ago (J Natl Cancer Inst 86: 312-4, 1994). Mature results confirm these unexpectedly favorable results with five advanced sarcoma patients still surviving after more than three years (four more than four years).

HYPOTHESIS

Molgramostim given subcutaneously in a relatively intensive schedule might enhance the antitumor effects initiated by cytotoxic drugs in patients with advanced sarcomas. This idea should be tested formally in phase III studies.

Involvement of trihydroxyconjugated bile salts in cholesterol assimilation by bifidobacteria

To determine the conditions of cholesterol assimilation,various strains of Bifidobacterium species were cultured in the presence of cholesterol and bile salts. During culturing, Bifidobacterium breve ATCC 15700 assimilates cholesterol in the presence of oxgall at pH values lower than 6. This strain was selected to study the influence of conjugated (taurocholic acid) and deconjugated (cholic acid) bile salts on cholesterol assimilation. B. breve ATCC 15700 assimilated cholesterol(up to 51%) when cultures were undertaken in the presence of taurocholic acid, whereas less than 13% of the initial amount ofcholesterol was measured in the cells in the presence of cholic acid. Cultured in the presence of six individual di- or trihydroxyconjugated bile salts, bifidobacteria strains assimilated cholesterol. This assimilation appeared to be more important in the presence of trihydroxyconjugated bile salts (tauro- and glycocholic acids). It is concluded thattrihydroxyconjugated bile salts are involved in the assimilation of cholesterol by bifidobacteria.

Bifidobacteria strain behavior toward cholesterol: coprecipitation with bile salts and assimilation

Resting cells and growing cells of bifidobacteria strains exhibited an ability to remove cholesterol in the presence of bile salts. In resting cell assays, the removed cholesterol was precipitated in the presence of cholic acid at pH values lower than 5.4. However, this precipitated cholesterol was redissolved when the pellets were washed with phosphate buffer, pH 7, and no cholesterol was found in the cells. It appears that this precipitation is a transient phenomenon. In the case of growing cells, the removed cholesterol was partially recovered when cells were washed with phosphate buffer, pH 7, while the remaining cholesterol was extracted from the cells. Cultured in the presence of radiolabeled free or esterified cholesterol, bifidobacteria strains were able to assimilate esterified cholesterol. It is concluded that the removal of cholesterol from the growth medium by bifidobacteria strains is due to both bacterial assimilation and precipitation of cholesterol.

Adhesion of different bifidobacteria strains to human enterocyte-like Caco-2 cells and comparison with in vivo study

The validity of the in vitro adhesion tests performed with cultured cell lines, was determined in this study by comparison with results obtained in vivo, in a previous study. To make this experiment the in vitro adhesion tests were performed during a long period by utilization of an appropriate medium, to determine the capacity of the adhered strain to colonize the intestinal tract. It was demonstrated that the ability of the strain to adhere and colonize the intestinal cell in vivo or the cultured intestinal cells in intro was similar.

Bifidobacteria and probiotic effects: action of Bifidobacterium species on conjugated bile salts

The effect of six different conjugated bile salts (two trihydroxyconjugated bile salts: tauro and glycocholic acids; and four dihydroxyconjugated bile salts: tauro- and glycochenodeoxycholic, tauro- and glycodeoxycholic acids) on eight bifidobacteria strains were studied. A strong growth-inhibitory effect was observed (80% at 0.95 mM) for each bile salt and strain. This phenomenon was explained by the production of deconjugated bile salt during bifidobacteria growth. The deconjugation phenomenon was concurrent with biomass production, and deconjugated bile salts were the sole compound produced during bifidobacteria biotransformation. In resting cell experiments, differences appeared between the strains and the kind of bile salts, particularly concerning taurocholic acid. The Bifidobacterium longum strains were the most efficient among the bacteria tested.

Characterization of fructose 6 phosphate phosphoketolases purified from Bifidobacterium species

Fructose 6 phosphate phosphoketolases (F6PPKs) were purified from Bifidobacterium longum BB536, B. dentium ATCC 27534, B. globosum ATCC 25864, and Bifidobacterium animalis ATCC 25527. Concerning ions (Cu++, Zn++, Ca++, Mg++, Fe++, Co++, Mn++) and common enzyme inhibitors (fructose, ammonium sulfate, iodoacetate, and parachloromercuribenzoic acid), no difference appeared between the enzymes. Cu++, parachloromercuribenzoic acid (pCMB), and mercuric acetate induced high enzymatic inhibition. The study of pCMB demonstrated a noncompetitive inhibition. Additional results showed that the sulfhydryl group was not involved in catalytic reaction. Photooxidation experiments and determination of ionizable group pKas (5.16-7.17) suggested the presence of one or more histidines necessary for the catalytic reaction and explained the inhibition observed with pCMB. In light of the noncompetitive inhibition, this group was not directly involved in substrate binding. Determination of Km demonstrated that the affinities for fructose 6 phosphate in the case of animal and human origin strains were close. In addition, the same enzymatic efficiency (Kcat/Km) was obtained for each strain. The F6PPK activity was regulated by sodium pyrophosphate, ATP, and especially by ADP.

Effect of bifidobacteria on nitrites and nitrosamines

The effects of six different bifidobacteria strains were studied on two procarcinogens: nitrite and nitrosamines. Growth of bifidobacteria was not affected by nitrite concentrations below 50 mumol l-1. At nitrite concentrations greater than 2000 mumol l-1, total growth inhibition was observed. Nitrite elimination by a non-enzymic mechanism was noted for six strains of bifidobacteria. Acids produced by the bacteria seem to be involved in nitrite elimination. Nitrosamines tested had no effect on growth of bifidobacteria. Only one strain (Bifidobacterium longum BB 536) was able to metabolize nitrosamines by an intracellular mechanism.

Management of stage IE primary gastric lymphoma

From 1975 to 1991, stage IE gastric lymphoma was diagnosed or treated in 40 patients at our institution. Thirty-five evaluable patients were the subject of this analysis (median age, 63 years). All histologic specimens were reviewed and classified according to the working formulation. Immunohistochemical stains were performed in 33 of 35 cases. The following histologic subtypes were identified: 26 patients had diffuse large cell, 2 had diffuse mixed cell, and 7 had mucosa-associated lymphocytic lymphoma (small lymphocytic lymphoma with features of MALT lymphoma). Of the 35 patients, 30 (86%) underwent laparotomy, with subtotal or total gastrectomy performed in 29. After gastrectomy, 17 patients had radiation therapy, 3 had chemotherapy, 2 had radiation plus chemotherapy, and 7 had no further treatment. Five patients were diagnosed with endoscopic biopsy and had radiation therapy, chemotherapy, or both without further surgical treatment. The median follow-up period was 69.2 months. The commonest presenting symptom was pain. The 5-year disease-free survival was 90% for the entire group and 88% for the 28 patients with working formulation intermediate histology. For patients with MALT lymphoma, the 5-year disease-free survival was 100%. The prognosis for patients with stage IE working formulation intermediate-histology gastric lymphoma is good and for those with stage IE MALT lymphoma, excellent.

Prognostic value of c-erbB2 overexpression in axillary lymph node positive breast cancer. Results from a randomized adjuvant treatment protocol

BACKGROUND

This study was designed to evaluate the prognostic importance of c-erbB2 overexpression in a standardized cohort of patients with axillary lymph node positive breast cancer.

METHODS

Paraffin embedded primary breast cancers from 354 patients with axillary lymph node positive breast cancer, treated on a North Central Cancer Treatment Group adjuvant protocol, were studied immunohistochemically. c-erbB2 staining was classified as negative, weak (1+), moderate (2+), or strong (3+) and was assessed for effectiveness as a predictor of outcome in univariate and Cox model multivariate analyses.

RESULTS

Twenty percent of specimens exhibited moderate or strong c-erbB2 staining. The median disease free survival period of the strong staining group was 2.9 years, compared with 7.1 years for all other patients (P = 0.01). The median overall survival for the strong staining group was 5 years, compared with 12 years for all other patients (P = 0.03). A definite correlation was noted between degree of nodal involvement and the likelihood of strong c-erbB2 staining (P = 0.001). There was also a significant correlation between c-erbB2 staining and higher nuclear grade and estrogen receptor negativity. In a multivariate analysis, c-erbB2 staining was not a significant predictor of either disease free survival or overall survival.

CONCLUSION

According to this analysis, the strong correlation between c-erbB2 expression and degree of nodal involvement, higher grade disease, and estrogen receptor negativity suggests expression of this protooncogene product in a biologically more aggressive form of breast cancer. In a multivariate analysis, c-erbB2 expression was not an independent prognostic factor. Thus, c-erbB2 assessment did not appear to add significantly to the information provided by currently available standard disease parameters.

Tonsil cancer. Patterns of failure after surgery alone and surgery combined with postoperative radiation therapy

BACKGROUND

The authors determined the patterns of treatment failure in patients treated with surgery alone or surgery combined with postoperative radiation therapy for squamous cell carcinoma of the tonsil.

METHODS

Seventy-two patients underwent surgery alone (56) or surgery and postoperative adjuvant radiation therapy (16). All patients were followed up until death (40 patients) or for a minimum of 3.5 years. For patients treated with surgery alone, clinic notes, operative notes, and pathology reports and slides were reviewed to identify clinical or pathologic predictors of recurrence above the clavicles, cause-specific survival, and overall survival. For patients undergoing postoperative adjuvant radiation therapy, demographic, treatment, and pathologic variables were analyzed to identify factors associated with control of disease above the clavicles, disease-free survival, and overall survival.

RESULTS

The main pattern of treatment failure was above the clavicles. It occurred in 39% of patients treated with surgery alone and was significantly related (P = 0.002) to the overall clinical TNM stage. Disease recurrence above the clavicles occurred in 31% of patients undergoing surgery and postoperative adjuvant radiation therapy, despite their more advanced neck disease. Five-year overall survival for patients with clinical Stage III and IV disease who were treated with surgery and post-operative adjuvant radiation therapy was 100% and 78%, respectively. Five-year overall survival for patients treated with surgery alone who had clinical Stage III, IVA, or IVB disease was 56%, 43%, and 50%, respectively.

CONCLUSION

We recommend postoperative adjuvant radiation therapy for patients with clinical Stage III or IV squamous cell carcinoma of the tonsil who have undergone complete surgical resection because this appears to improve control of disease above the clavicles and overall survival.

Prognostic significance of p53 immunostaining in epithelial ovarian cancer

PURPOSE

To evaluate the prognostic significance of p53 expression in epithelial ovarian cancer, including a subset of stage I patients, and to look for correlations between p53 expression and other disease parameters, including stage, grade, age, histologic subtype, second-look results, ploidy, and percent S phase.

PATIENTS AND METHODS

We analyzed p53 expression in 284 patients with epithelial ovarian cancer using immunohistochemical techniques in paraffin-embedded specimens. There were 36 patients with stage I disease, 20 with stage II disease, 186 with stage III disease, and 42 with stage IV disease.

RESULTS

p53 immunoreactivity was present in 177 cases (62%). p53 expression was associated with grade 3 to 4 disease (P = .003). The following factors were associated with a decrease in overall survival in a univarate analysis: stage III or IV disease (P = .0001), grade 3 or 4 disease (P = .0001), age above the median (P = .0002), and p53 reactivity (P = .04). In a multivariate analysis, stage, grade, and age retained independent prognostic significance. In the subset of 36 stage I patients, p53 positively approached statistical significance (P = .10) as a negative prognostic factor in a univariate analysis.

CONCLUSION

Abnormalities of p53 expression occur commonly in epithelial ovarian cancer. Although associated with decreased survival in a univariate analysis, this biologic marker did not retain independent prognostic significance in a multivariate analysis. p53 expression should be studied in a larger cohort of early-stage patients, where accurate prognostic information is needed to direct therapy.