Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Bilateral vertebral arteries entering the C4 foramen transversarium with the left vertebral artery originating from the aortic arch

Vertebral arteries (VAs) serve as major blood vessels to the central nervous system. VAs typically arise from the subclavian arteries and ascend separately within the transverse foramina of the cervical vertebrae (C6-C1) before entering the skull at the foramen magnum and joining at the base of the pons to form the basilar artery of the vertebrobasilar circulation. Therefore, variations in the origin and anatomic course of the VAs have implications for invasive medical procedures involving the superior thoracic/cervical regions or the cervical vertebrae. The current case report describes variation in the entry point of both VAs and the site of origin of the left vertebral artery. The variation was revealed during routine dissection of a 72-year-old female cadaver. It was found that the left vertebral artery originated directly from the aortic arch to abnormally enter the transverse foramen of C4 instead of the transverse foramen of C6. The right vertebral artery arose as usual from the right subclavian artery. However, the right vertebral artery also directly entered the transverse foramen of C4 instead of the transverse foramen of C6.

What's in a Prerequisite? A Mixed-Methods Approach to Identifying the Impact of a Prerequisite Course

Despite the ubiquity of prerequisites in undergraduate science, technology, engineering, and mathematics curricula, there has been minimal effort to assess their value in a data-driven manner. Using both quantitative and qualitative data, we examined the impact of prerequisites in the context of a microbiology lecture and lab course pairing. Through interviews and an online survey, students highlighted a number of positive attributes of prerequisites, including their role in knowledge acquisition, along with negative impacts, such as perhaps needlessly increasing time to degree and adding to the cost of education. We also identified a number of reasons why individuals do or do not enroll in prerequisite courses, many of which were not related to student learning. In our particular curriculum, students did not believe the microbiology lecture course impacted success in the lab, which agrees with our analysis of lab course performance using a previously established "familiarity" scale. These conclusions highlight the importance of soliciting and analyzing student feedback, and triangulating these data with quantitative performance metrics to assess the state of science, technology, engineering, and mathematics curricula.

Brewing for Students: An Inquiry-Based Microbiology Lab

In an effort to improve and assess student learning, there has been a push to increase the incorporation of discovery-driven modules and those that contain real-world relevance into laboratory curricula. To further this effort, we have developed, implemented, and assessed an undergraduate microbiology laboratory experiment that requires students to use the scientific method while brewing beer. The experiment allows students to brew their own beer and characterize it based on taste, alcohol content, calorie content, pH, and standard reference method. In addition, we assessed whether students were capable of achieving the module learning objectives through a pre-/posttest, student self-evaluation, exam-embedded questions, and an associated worksheet. These objectives included describing the role of the brewing ingredients and predicting how altering the ingredients would affect the characteristics of the beer, amongst others. By completing this experimental module, students accomplished the module objectives, had greater interest in brewing, and were more likely to view beer in scientific terms. Journal of Microbiology & Biology Education.

Sugars and adiposity: the long-term effects of consuming added and naturally occurring sugars in foods and in beverages

OBJECTIVE

The aim of this study was to determine if the association with adiposity varies by the type (added vs. naturally occurring) and form (liquid vs. solid) of dietary sugars consumed.

METHODS

Data from the 10-year National Heart, Lung, and Blood Institute (NHLBI) Growth and Health Study (n = 2,021 girls aged 9-10 years at baseline; n = 5,156 paired observations) were used. Using mixed linear models, 1-year changes in sugar intake, body mass index z-score (BMIz) and waist circumference (WC) were assessed.

RESULTS

The results showed mean daily added sugar (AS) intake: 10.3 tsp (41 g) liquid; 11.6 tsp (46 g) solid and naturally occurring sugar intake: 2.6 tsp (10 g) liquid; 2.2 tsp (9 g) solid. Before total energy adjustment, each additional teaspoon of liquid AS was associated with a 0.222-mm increase in WC (p = 0.0003) and a 0.002 increase in BMIz (p = 0.003). Each teaspoon of solid AS was associated with a 0.126-mm increase in WC (p = 0.03) and a 0.001 increase in BMIz (p = 0.03). Adjusting for total energy, this association was maintained only between liquid AS and WC among all and between solid AS and WC among those overweight/obese only. There was no significant association with naturally occurring sugar.

CONCLUSIONS

These findings demonstrate to suggest a positive association between AS intake (liquid and solid) and BMI that is mediated by total energy intake and an association with WC that is independent of it.

Evolution of biomarker guided therapy for heart failure: current concepts and trial evidence

Optimizing management of patients with heart failure remains quite challenging despite many significant advances in drug and device therapy for this syndrome. Although a large body of evidence from robust clinical trials supports multiple thera-pies, utilization of these well-established treatments remains inconsistent and outcomes suboptimal in “real-world” patients with heart failure. Disease management programs may be effective, but are difficult to implement due to cost and logistical issues. Another approach to optimizing therapy is to utilize biomarkers to guide therapeutic choices. Natriuretic peptides pro-vide additional information of significant clinical value in the diagnosis and estimation of risk inpatients with heart failure. Ongoing research suggests a potential important added role for natriuretic peptides in heart failure. Guiding therapy based on serial changes in these biomarkers may be an effective strategy to optimize treatment and achieve better outcomes in this syn-drome. Initial, innovative, proof-of-concept studies have provided encouraging results and important insights into key as-pects of this strategy, but well designed, large-scale, multicenter, randomized, outcome trials are needed to definitively estab-lish this novel approach to management. Given the immense and growing public health burden of heart failure, identification of cost-effective ways to decrease the morbidity and mortality due to this syndrome is critical.

Addition of short-term androgen deprivation therapy to dose-escalated radiation therapy improves failure-free survival for select men with intermediate-risk prostate cancer

BACKGROUND

Dose-escalated (DE) radiation therapy (RT) and androgen deprivation therapy (ADT) improve prostate cancer outcomes over standard-dose RT. The benefit of adding ADT to DE-RT for men with intermediate-risk prostate cancer (IR-PrCa) is uncertain.

PATIENTS AND METHODS

We identified 636 men treated for IR-PrCa with DE-RT (>75Gy). The adult comorbidity evaluation-27 index classifed comorbidity. Kaplan-Meier and log-rank tests compared failure-free survival (FFS) with and without ADT.

RESULTS

Forty-five percent received DE-RT and 55% DE-RT with ADT (median 6 months). On Cox proportional hazard regression that adjusted for comorbidity and tumor characteristics, ADT improved FFS (adjusted hazard ratio 0.36; P = 0.004). Recursive partitioning analysis of men without ADT classified Gleason 4 + 3 = 7 or ≥50% positive cores as unfavorable disease. The addition of ADT to DE-RT improved 5-year FFS for men with unfavorable disease (81.6% versus 92.9%; P = 0.009) but did not improve FFS for men with favorable disease (96.3% versus 97.4%; P = 0.874). When stratified by comorbidity, ADT improved FFS for men with unfavorable disease and no or mild comorbidity (P = 0.006) but did not improve FFS for men with unfavorable disease and moderate or severe comorbidity (P = 0.380).

CONCLUSION

The addition of ADT to DE-RT improves FFS for men with unfavorable IR-PrCa, especially those with no or minimal comorbidity.

Intensity modulated proton therapy treatment planning using single-field optimization: the impact of monitor unit constraints on plan quality

PURPOSE

To investigate the effect of monitor unit (MU) constraints on the dose distribution created by intensity modulated proton therapy (IMPT) treatment planning using single-field optimization (SFO).

METHODS

Ninety-four energies between 72.5 and 221.8 MeV are available for scanning beam IMPT delivery at our institution. The minimum and maximum MUs for delivering each pencil beam (spot) are 0.005 and 0.04, respectively. These MU constraints are not considered during optimization by the treatment planning system; spots are converted to deliverable MUs during postprocessing. Treatment plans for delivering uniform doses to rectangular volumes with and without MU constraints were generated for different target doses, spot spacings, spread-out Bragg peak (SOBP) widths, and ranges in a homogeneous phantom. Four prostate cancer patients were planned with and without MU constraints using different spot spacings. Rounding errors were analyzed using an in-house software tool.

RESULTS

From the phantom study, the authors have found that both the number of spots that have rounding errors and the magnitude of the distortion of the dose distribution from the ideally optimized distribution increases as the field dose, spot spacing, and range decrease and as the SOBP width increases. From our study of patient plans, it is clear that as the spot spacing decreases the rounding error increases, and the dose coverage of the target volume becomes unacceptable for very small spot spacings.

CONCLUSIONS

Constraints on deliverable MU for each spot could create a significant distortion from the ideally optimized dose distributions for IMPT fields using SFO. To eliminate this problem, the treatment planning system should incorporate the MU constraints in the optimization process and the delivery system should reliably delivery smaller minimum MUs.

Smoking, alcohol and gastric cancer risk in Korean men: the National Health Insurance Corporation Study

We investigated the risk of gastric cancer by subsite in relation to cigarette smoking and alcohol in a large population-based cohort of 669 570 Korean men in an insurance plan followed for an average 6.5 years, yielding 3452 new cases of gastric cancer, of which 127 were cardia and upper-third gastric cancer, 2409 were distal gastric cancer and 1007 were unclassified. A moderate association was found between smoking, cardia and upper-third (adjusted relative risk (aRR) 2.2; 95% confidence interval (CI) 1.4-3.5) and distal cancers (aRR=1.4; 95% CI=1.3-1.6). We also found a positive association between alcohol consumption and distal (aRR=1.3; 95% CI=1.2-1.5) and total (aRR=1.2; 95% CI=1.1-1.4) gastric cancer. Combined exposure to high levels of tobacco and alcohol increased the risk estimates further; cardia and upper-third gastric cancers were more strongly related to smoking status than distal gastric cancer.British Journal of Cancer (2007) 97, 700-704. doi:10.1038/sj.bjc.6603893 www.bjcancer.com Published online 17 July 2007.

Role of plasma membrane calcium ATPase isoform 2 in neuronal function in the cerebellum and spinal cord

The distinct role of plasma membrane calcium ATPase 2 (PMCA2) in the function of different neuronal subpopulations in the central nervous system is not well understood. We found that lack of PMCA2 leads to a reduction in the number of motor neurons in the spinal cord of PMCA2-null mice and to abnormal changes in molecular pathways in Purkinje cells. Thus, PMCA2 may have unique, nonredundant functions in spinal cord and cerebellar neurons. Our results suggest that anomalous alterations in PMCA2 activity or expression may induce pathology in some neuronal populations, a possibility that will be the focus of future investigations.

Molecular alterations in the cerebellum of the plasma membrane calcium ATPase 2 (PMCA2)-null mouse indicate abnormalities in Purkinje neurons

PMCA2, a major calcium pump, is expressed at particularly high levels in Purkinje neurons. Accordingly, PMCA2-null mice exhibit ataxia suggesting cerebellar pathology. It is not yet known how changes in PMCA2 expression or activity affect molecular pathways in Purkinje neurons. We now report that the levels of metabotropic glutamate receptor 1 (mGluR1), which plays essential roles in motor coordination, synaptic plasticity, and associative learning, are reduced in the cerebellum of PMCA2-null mice as compared to wild type littermates. The levels of inositol 1,4,5-triphosphate receptor type 1 (IP3R1), an effector downstream to mGluR1, which mediates intracellular calcium signaling, and the expression of Homer 1b/c and Homer 3, scaffold proteins that couple mGluR1 to IP3R1, are also reduced in somata and dendrites of some Purkinje cell subpopulations. In contrast, no alterations occur in the levels of mGluR1 and its downstream effectors in the hippocampus, indicating that the changes are region specific. The reduction in cerebellar mGluR1, IP3R1 and Homer 3 levels are neither due to a generic decrease in Purkinje proteins nor extensive dendritic loss as immunoreactivity to total and non-phosphorylated neurofilament H (NFH) is increased in Purkinje dendrites and microtubule associated protein 2 (MAP2) staining reveals a dense dendritic network in the molecular layer of the PMCA2-null mouse cerebellum. PMCA2 coimmunoprecipitates with mGluR1, Homer 3 and IP3R1, suggesting that the calcium pump is a constituent of the mGluR1 signaling complex. Our results suggest that the decrease in the expression of mGluR1 and its downstream effectors and perturbations in the mGluR1 signaling complex in the absence of PMCA2 may cumulatively result in aberrant metabotropic glutamate receptor signaling in Purkinje neurons leading to cerebellar deficits in the PMCA2-null mouse.

Microbial iron respiration: impacts on corrosion processes

In this review, we focus on how biofilms comprising iron-respiring bacteria influence steel corrosion. Specifically, we discuss how biofilm growth can affect the chemistry of the environment around the steel at different stages of biofilm development, under static or dynamic fluid regimes. We suggest that a mechanistic understanding of the role of biofilm metabolic activity may facilitate corrosion control.

Enhanced expression of microsomal epoxide hydrolase and glutathione S-transferase by imidazole correlates with the radioprotective effect

Previous studies have shown that induction of microsomal epoxide hydrolase (mEH) and glutathione S-transferase (GST) by oltipraz correlated with the radioprotective effect. The present study was designed to investigate the expression of the antioxidant enzymes and the radioprotective effect by imidazole (IM). Northern blot analysis revealed that IM increased the mEH and GST mRNA levels in the rat liver in a dose-dependent manner. Rats irradiated with 3 Gy of gamma-rays in combination with IM showed enhanced increases in mEH and rGSTA2 mRNAs, as compared to either IM or irradiation alone. IM prevented elevations in the hepatic GSH content by gamma-irradiation. In contrast to IM, cysteine blocked radiation-inducible increases in the mRNAs with no suppression of the GSH content. The radioprotective effect by IM was greater than that by cysteine, as assessed by the 30-day survival rate of mice (i.e. 80% and 69%, respectively, vs. 48% in control). These results demonstrated that IM enhanced radiation-inducible mEH and GST expression with prevention of the increase in GSH content, which correlated with the radioprotective effect, and that the mechanistic basis of radioprotection by IM differed from that by cysteine.

Role of experience and oscillations in transforming a rate code into a temporal code

In the vast majority of brain areas, the firing rates of neurons, averaged over several hundred milliseconds to several seconds, can be strongly modulated by, and provide accurate information about, properties of their inputs. This is referred to as the rate code. However, the biophysical laws of synaptic plasticity require precise timing of spikes over short timescales (<10 ms). Hence it is critical to understand the physiological mechanisms that can generate precise spike timing in vivo, and the relationship between such a temporal code and a rate code. Here we propose a mechanism by which a temporal code can be generated through an interaction between an asymmetric rate code and oscillatory inhibition. Consistent with the predictions of our model, the rate and temporal codes of hippocampal pyramidal neurons are highly correlated. Furthermore, the temporal code becomes more robust with experience. The resulting spike timing satisfies the temporal order constraints of hebbian learning. Thus, oscillations and receptive field asymmetry may have a critical role in temporal sequence learning.

Primary histiocytic lymphoma of the central nervous system: a neoplasm frequently overshadowed by a prominent inflammatory component

True histiocytic lymphoma, as defined by strict criteria, is a very rare neoplasm. We describe three cases occurring as primary tumors in the central nervous system. The patients, two females and one male, ranged in age from 11 to 69 years. The tumors involved the brain in two cases and spinal cord in one, with a size ranging from 7 to 17 mm. Two patients died at 4 months and 8 months, respectively, and one was alive with disease at 5 months. Pathologically, the tumors comprised groups and sheets of noncohesive large cells with pleomorphic vesicular nuclei, distinct nucleoli, and abundant eosinophilic cytoplasm. A dense inflammatory infiltrate consisting of neutrophils, lymphocytes, plasma cells, and histiocytes was present, with multiple foci of necrosis and abscess formation. All three cases demonstrated an identical immunophenotype: positive for CD68 and lysozyme; focally positive for S-100 protein, CD45RB, and CD4; and negative for CD3, CD20, CD21/CD35, CD1a, CD30, ALK1, myeloperoxidase, glial fibrillary acidic protein, and cytokeratin. The proliferative index ranged from 20% to 35%. Ultrastructural examination further confirmed the histiocytic nature of the tumor cells, characterized by irregularly folded or multisegmented nuclei and abundant cytoplasm containing lysosomes; Birbeck granules, interdigitating cell processes, and cell junctions were not found. Although the presence of abundant inflammatory cells could obscure the neoplastic histiocytes, making the distinction from inflammatory conditions difficult, awareness of this unusual histologic feature and the invariable finding of pleomorphic cells in some areas of the lesion permit the correct diagnosis to be made.

Identification, characterization, and functional analysis of a gene encoding the ferric uptake regulation protein in Bartonella species

Environmental iron concentrations coordinately regulate transcription of genes involved in iron acquisition and virulence via the ferric uptake regulation (fur) system. We identified and sequenced the fur gene and flanking regions of three Bartonella species. The most notable difference between Bartonella Fur and other Fur proteins was a substantially higher predicted isoelectric point. No promoter activity or Fur autoregulation was detected using a gfp reporter gene fused to the 204 nucleotides immediately upstream of the Bartonella fur gene. Bartonella henselae fur gene expression complemented a Vibrio cholerae fur mutant.

Endocytosis in identified rat corticotrophs

1. We used the patch-clamp technique, in conjunction with membrane capacitance measurement, fluorescence measurement of intracellular calcium concentration ([Ca(2+)](i)), and flash photolysis of caged Ca(2+) to study exo- and endocytosis in identified rat corticotrophs. 2. Exocytosis stimulated by depolarization pulses was typically followed by a 'slow' endocytosis that retrieved the membrane with a time constant of approximately 6 s. The efficiency (the endocytosis/exocytosis amplitude ratio) of 'slow' endocytosis was approximately 1.2 at [Ca(2+)](i) < 3 microM and increased to approximately 1.6 at [Ca(2+)](i) > 3 microM. 3. Whole-cell dialysis through a patch pipette did not affect the kinetics and the efficiency of 'slow' endocytosis, but the amplitude of exocytosis was reduced. 4. 'Slow' endocytosis did not require sustained [Ca(2+)](i) elevation and its kinetics was only weakly [Ca(2+)](i) dependent. Our results suggest that 'slow' endocytosis involves a Ca(2+) sensor with a high Ca(2+) affinity (approximately 500 nM). 5. At high [Ca(2+)](i) (> 10 microM), the 'slow' endocytosis was frequently preceded by a 'fast' endocytosis that comprised multiple steps of rapid decrease in membrane capacitance. 6. Neither calmodulin nor calcineurin appeared to be the Ca(2+) sensor for endocytosis because the two forms of endocytosis were not affected by the calmodulin inhibitor calmidazolium (500 microM) or the calcineurin inhibitors cyclosporin A (1 microM) and calcineurin autoinhibitory peptide (1 mg ml(-1)). Ba(2+), a poor activator of calmodulin, could support both forms of endocytosis but slowed the kinetics of 'slow' endocytosis approximately 2-fold. 7. Non-hydrolysable analogues of GTP (GDP-beta-S) and ATP (ATP-gamma-S) also failed to inhibit either form of endocytosis, indicating that neither GTP nor ATP was essential for endocytosis. 8. We suggest that the high Ca(2+) affinity of 'slow' endocytosis may be important for maintaining continuous cycles of exocytosis-endocytosis during sustained adrenocorticotropin secretion in corticotrophs.

Optimizing patient selection for prostate monotherapy

PURPOSE

Patients at low risk for prostate-specific antigen (PSA) failure following definitive local therapy are those with PSA of 10 or less, biopsy Gleason Score of 6 or less, and 1992 American Joint Committee on Cancer (AJCC) clinical Stage T1c or T2a. However, low-risk patients managed with radical prostatectomy and found to have prostatectomy Gleason score > or = 3+4 have a less favorable PSA outcome when compared to patients with prostatectomy Gleason score < or = 3+3. This study was performed to determine whether the percentage of positive prostate biopsy cores could predict upgrading from a biopsy Gleason score of 6 or less to a prostatectomy Gleason score > or = 3+4 in low-risk patients to optimize selection for prostate only radiation therapy.

METHODS AND MATERIALS

Concordance testing of the biopsy Gleason score and the primary and secondary prostatectomy Gleason grades was performed in 427 prostate cancer patients treated with radical prostatectomy and at low risk for PSA failure. Logistic regression multivariable analysis was performed to test the ability of the established prognostic factors and the percentage of positive prostate biopsies (<34%, 34-50%, >50%) to predict for upgrading from biopsy Gleason score of 6 or less prostatectomy Gleason score > or = 3+4. PSA failure-free survival was reported using the actuarial method of Kaplan and Meier and comparisons were made using a log-rank test.

RESULTS

Twenty-nine percent of the 427 study patients were upgraded from a biopsy Gleason score of 6 or less to a prostatectomy Gleason score > or = 3+4. The presence of greater than 50% positive biopsies was the only significant factor for predicting the upgrading from biopsy Gleason score of 6 or less to prostatectomy Gleason score > or = 3+4 on logistic regression multivariable analysis with the variables treated as continuous and categorical. Specifically, upgrading occurred in 26% vs. 59% of patients with 50% or less vs. greater than 50% positive biopsies, respectively. This translated into a 5-year PSA failure-free survival which was significantly higher (92% vs. 62%, p = 0.00001) for men with 50% or less vs. greater than 50% positive prostate biopsies, respectively.

CONCLUSION

The presence of greater than 50% positive biopsies was associated with higher rates of pathologic upgrading which translated into lower 5-year PSA failure-free survival following radical prostatectomy (RP). Therefore, the percentage of positive biopsies may be useful in optimizing the selection of low-risk patients for prostate only radiation therapy such as external beam radiation or implant monotherapy.

mig-14 is a horizontally acquired, host-induced gene required for salmonella enterica lethal infection in the murine model of typhoid fever

We have characterized a host-induced virulence gene, mig-14, that is required for fatal infection in the mouse model of enteric fever. mig-14 is present in all Salmonella enterica subspecies I serovars and maps to a region of the chromosome that appears to have been acquired by horizontal transmission. A mig-14 mutant replicated in host tissues early after infection but was later cleared from the spleens and livers of infected animals. Bacterial clearance by the host occurred concomitantly with an increase in gamma interferon levels and recruitment of macrophages, but few neutrophils, to the infection foci. We hypothesize that the mig-14 gene product may repress immune system functions by interfering with normal cytokine expression in response to bacterial infections.

An unusual case of double tuberculous broncho-oesophageal fistulas in an adult

Broncho-oesophageal fistula associated with tuberculosis is rarely reported in the literature and has not been reported in Hong Kong. We describe a 30-year-old Chinese human immunodeficiency virus (HIV)-negative man with double tuberculous broncho-oesophageal fistulas proven by histology. Constitutional symptoms of active tuberculosis were absent and chest radiograph did not show an obvious lung lesion. Our case shows that broncho-oesophageal fistula can be the sole manifestation of active tuberculosis and that the diagnosis should be suspected in patients who are seen with chronic respiratory symptoms in areas where the prevalence of tuberculosis is high.

Voltage-gated Ca2+ channels and intracellular Ca2+ release regulate exocytosis in identified rat corticotrophs

1. The patch clamp technique was used in conjunction with a fluorescent Ca2+ indicator (indo-1, or indo-1FF) to measure simultaneously cytosolic Ca2+ concentration ([Ca2+]i) and exocytosis (changes in membrane capacitance) in single, identified rat corticotrophs. 2. Exocytosis could be stimulated by extracellular Ca2+ entry (via voltage-gated Ca2+ channels). A train of depolarizations could exhaust the pool of readily releasable granules and the pool replenished with a time constant of 42 s (at 22-25 C). 3. Recordings from cells with 0.5 mM intracellular cAMP showed that the amplitude of the depolarization-triggered exocytosis, the Ca2+ sensitivity of exocytosis, as well as the rate of replenishment of the readily releasable pool, were similar to the controls. 4. Exocytosis could also be stimulated by intracellular Ca2+ release from the inositol 1,4, 5-trisphosphate (IP3)-sensitive store (via flash photolysis of caged IP3). At comparable [Ca2+]i, extracellular Ca2+ entry and intracellular Ca2+ release had similar efficacy in triggering exocytosis. 5. The rate of exocytosis triggered via depolarization or intracellular Ca2+ release was much faster than that triggered via uniform elevation of [Ca2+]i (Ca2+ dialysis or flash photolysis of caged Ca2+). 6. The above findings suggest that both intracellular Ca2+ release and voltage-gated extracellular Ca2+ entry generate a spatial Ca2+ gradient, such that the local [Ca2+] near the exocytic sites was approximately 3-fold higher than the mean cytosolic [Ca2+]. However, neither cAMP nor the spatial Ca2+ gradient generated during depolarization could account for the high efficacy of corticotropin-releasing hormone (CRH) in stimulating adrenocorticotropic hormone (ACTH) secretion from corticotrophs.

Relationship between lifting capacity and anthropometric measures

STUDY DESIGN

Prospective analysis of relationship between lifting capacity and multiple anthropometric variables.

OBJECTIVES

To determine the relationship between lifting capacity and anthropometric variables and to model this relationship quantitatively.

BACKGROUND

Low-back injuries commonly occur in individuals who perform lifting tasks. Objective data are needed to determine preinjury lifting capacity that, in turn, might be used to guide decisions during rehabilitation of these injuries.

METHODS AND MEASURES

We recorded age and sex and measured the following variables for 35 men and 23 women between the ages of 22 and 40: height, weight, percentage of body fat, torso height, pelvic width, pelvic girth, arm length, thigh girth, and calf girth. Variables were selected for the study on the basis of theoretical modeling or previous research regarding the relationship between study variables and lifting capacity. Subjects also were tested to determine their maximum lifting capacity by using a lordotic lumbar spine lifting technique.

RESULTS

Stepwise regression analysis indicated that the combination of sex, age, thigh girth, pelvic girth, and percentage body fat was significantly related to maximum lift capacity (multiple R2 = 0.76). The mean absolute difference (+/- SD) between lifted amount predicted by the regression model and the actual amount lifted was 118.6 +/- 86 N (26 +/- 19.3 lb), which corresponded to an average absolute error of 16% (SD = 14%) of the actual weight lifted.

CONCLUSION

The results may be useful in estimating 1 aspect of preinjury lifting capacity. Similar studies are needed to model the requirements of frequency of lift, duration of lifting efforts, variety of hand-object coupling, and combined lifting and reaching.

OmpR regulates the two-component system SsrA-ssrB in Salmonella pathogenicity island 2

Salmonella pathogenicity island 2 (SPI-2) encodes a putative, two-component regulatory system, SsrA-SsrB, which regulates a type III secretion system needed for replication inside macrophages and systemic infection in mice. The sensor and regulator homologs, ssrAB (spiR), and genes within the secretion system, including the structural gene ssaH, are transcribed after Salmonella enters host cells. We have studied the transcriptional regulation of ssrAB and the secretion system by using gfp fusions to the ssrA and ssaH promoters. We found that early transcription of ssrA, after entry into macrophages, is most efficient in the presence of OmpR. An ompR mutant strain does not exhibit replication within cultured macrophages. Furthermore, footprint analysis shows that purified OmpR protein binds directly to the ssrA promoter region. We also show that minimal medium, pH 4.5, induces SPI-2 gene expression in wild-type but not ompR mutant strains. We conclude that the type III secretion system of SPI-2 is regulated by OmpR, which activates expression of ssrA soon after Salmonella enters the macrophage.

Oklahoma notes decline in Haemophilus influenzae: invasive Haemophilus influenzae disease among children aged < 5 years--Oklahoma, 1990-1997

Haemophilus influenzae (Hi) causes many clinical illnesses such as meningitis, bacteremia, epiglottitis, pneumonia, otitis media, sinusitis and tracheobronchitis. Before the introduction of the Haemophilus influenzae type b (Hib) conjugate vaccine in 1988, Hib caused more than 95 percent of invasive Hi disease in developed countries. Conjugate vaccines were licensed for use in children > or = 15 months of age in 1989 and for use in children > or = 2 months of age in 1990. During 1987-1995, the incidence of invasive Hi disease among children < 5 years of age decreased 96 percent in the United States. This report summarizes the trend in invasive disease caused by Hi among Oklahoma children < 5 years of age. The data represents cases reported to the OSDH as part of the infectious disease surveillance system. Invasive Hi disease has been reportable by law in Oklahoma since 1983.

Sarcoidosis-related anterior uveitis in a patient with human immunodeficiency virus

BACKGROUND

This is the first ophthalmic report--to our knowledge--of an anterior uveitis secondary to sarcoidosis in a patient infected with human immunodeficiency virus (HIV). Other reported causes of uveitis in HIV-infected patients have included HIV, herpes zoster, tuberculosis, syphilis, toxoplasmosis, cryptococcus, rifabutin prophylaxis for mycobacterium, and protease inhibitors such as ritonavir and indinavir. Uveitis secondary to sarcoidosis in the non-HIV population is classically seen in young, female, African-American patients. There are rare reports, found exclusively in the pulmonary literature, of sarcoidosis in HIV-infected patients.

CASE REPORT

A 38-year-old African-American male infected with HIV was treated for chronic recurrent anterior uveitis secondary to sarcoidosis. His sarcoidosis was diagnosed 1 month earlier, along with the onset of his uveitis. During the previous 6 years he has been treated with anti-HIV antivirals as well as prophylaxis for opportunistic infections. To date, his infectious disease specialist continues to treat his HIV and systemic sarcoidosis.

CONCLUSION

Patients with HIV infection in whom sarcoidosis with secondary uveitis develops are very rare. Management of these patients requires careful use of topical and oral steroidal anti-inflammatories to control ocular and systemic sequelae of sarcoidosis. This case initiates some interesting questions about the immunology of sarcoidosis and its presence in immunocompromised patients. Use of steroids in an immunocompromised patient is clinically complex. Further clinical study is needed to elicit the full clinical significance of sarcoidosis and HIV infection.

Constitutive and inducible green fluorescent protein expression in Bartonella henselae

The green fluorescent protein (GFP) gene was expressed on a plasmid in B. henselae, and GFP-expressing bacteria were visualized by fluorescence microscopy. HEp-2 cells infected with GFP-expressing bacteria were separated from uninfected cells with a fluorescence activated cell sorter. Promoter fusions of B. henselae chromosomal DNA to gfp were examined by flow cytometry, and a B. henselae groEL promoter fusion which induced expression at 37 degreesC was isolated.

Recombinant dengue virus type 1 NS3 protein exhibits specific viral RNA binding and NTPase activity regulated by the NS5 protein

The full-length dengue virus NS3 protein has been successfully expressed as a 94-kDa GST fusion protein in Escherichia coli. Treatment of the purified fusion protein with thrombin released a 68-kDa protein which is the expected molecular mass for the DEN1 NS3 protein. The identity of this protein was confirmed by Western blotting using dengue virus antisera. Two related activities of the recombinant NS3 protein were characterized, which were the binding of the protein to the 3'-noncoding region of the dengue virus RNA genome and NTPase activity. We demonstrated using a band shift assay that the DEN1 NS3 protein could form a complex with the stem-loop structure in the 3'-noncoding region (3'-NCR), although sites outside the stem-loop may also participate in binding. Using various unlabeled homopolymeric and heteropolymeric RNAs as competitors for binding, it was further shown that the DEN1 NS3 protein exhibits preferential binding to a 94-nt RNA transcript from the 3'-NCR of the dengue virus. The NTPase activity of the recombinant DEN1 NS3 protein was characterized using a thin-layer chromatography assay. We found that the DEN1 NS3 protein possesses some aspects of NTPase activity, which are distinct from those found in other flaviviruses. Although the NS3 protein was able to utilize all four ribonucleoside triphosphates as its substrates, the NS3 protein showed a distinct preference for purine triphosphates (i.e., ATP and GTP). The addition of poly(U) did not stimulate NTPase activity in DEN1 NS3 protein, which contrasts with the reports for other flaviviral NS3 proteins. However, NTPase activity was specifically stimulated by the viral NS5 protein, which was manifested by a more than twofold increase in the rate of ATP hydrolysis and a 25% increase in the yield of ADP at the end of a 120-min reaction. These data suggest that the NTPase activity of the NS3 protein may be regulated by the viral NS5 protein during virus replication.

Arginine vasopressin triggers intracellular calcium release, a calcium-activated potassium current and exocytosis in identified rat corticotropes

Arginine vasopressin (AVP) stimulates the secretion of ACTH from pituitary corticotropes. We investigated the action of AVP in single corticotropes of male rats. Corticotropes were identified with the reverse hemolytic plaque assay using antibodies against ACTH. Using the whole-cell recording technique in conjunction with the fluorescent Ca2+ indicator, indo-1 to measure the concentration of cytosolic free Ca2+ ([Ca2+]i), we show that AVP triggers a transient and plateau pattern of Ca2+ signal. The [Ca2+]i elevation activates the apamin-sensitive Ca2+-activated K+ current, which, in turn, causes membrane hyperpolarization. The Ca2+ signal can be elicited in the absence of extracellular Ca2+ and is mimicked by intracellular inositol 1,4,5-trisphosphate (IP3). Both GDP-beta-S and heparin inhibit the AVP response. Thus, AVP triggers intracellular Ca2+ release from the (IP3)-sensitive store via a GTP binding protein-coupled phosphoinositide pathway. Using the high temporal resolution capacitance measurement to detect exocytosis in single corticotropes, we show that a burst of exocytosis is evoked during the AVP-triggered [Ca2+]i elevation. Exocytosis can also be triggered when Ca2+ is released directly from the IP3-sensitive store via flash photolysis of caged IP3. We conclude that AVP-stimulated ACTH secretion in rat corticotrophs is closely coupled to intracellular Ca2+ release from the IP3-sensitive store.

Partial hepatoprotective effects of allylthiobenzimidazole in the absence of cytochrome P4502E1 suppression: effects on epoxide hydrolase, rGSTA2, rGSTA3/5, rGSTM1 and rGSTM2 expression

1. 2-(Allylthio)pyrazine protects the liver against acetaminophen- and carbon tetrachloride-induced injury through inhibition of cytochrome P4502E1 and induction of glutathione S-transferases (GSTs). By comparison, the effects of allylthiobenzimidazole (ATB) on the levels of several hepatic cytochrome P450, microsomal epoxide hydrolase (mEH) and GST expression have been studied in the rat herein. 2. Western immunoblotting analyses revealed that ATB treatment (50 mg/kg/day for 5 days) failed to alter cytochrome P4501A2, P4502B1/2 and P4502E1 levels in the liver, whereas the expression of P4502C11 was reduced approximately 50% by ATB. 3. Treatment of rat with a single dose of ATB resulted in 2-21-fold increases in mEH mRNA levels at 24 h with an ED50 = 60 mg/kg. mEH mRNA level was elevated 9- and 21-fold at 12 and 24 h after treatment at 200 mg/kg respectively as compared with control. Western blot analysis revealed that ATB induced mEH protein levels by 2-fold relative to control. 4. ATB induced the major GST mRNA levels as a function of dose, resulting in rGSTA2, rGSTA3/5 and rGSTM1 mRNA levels elevated by 20-, 6- and 8-fold at 24 h respectively. The relative rGSTM2 mRNA level was minimally affected. Time-course studies showed that mEH, rGSTA2 and rGSTM1 mRNA levels were significantly increased at 12 and 24 h after ATB treatment, returning to control levels by 48 h. Treatment of rat with ATB (20-50 mg/kg/day for 5 days) resulted in 2-3-fold increases in mEH, rGSTA1/2, rGSTA3/5 and rGSTM1 mRNA levels with the induction of GST subunits. 5. ATB failed to block carbon tetrachloride-induced liver toxicity in rat and mouse. ATB treatment (50 mg/kg day for 3 days) prior to a lethal dose of acetaminophen significantly reduced acetaminophen-induced liver toxicity in mouse, as assessed by both plasma alanine aminotransferase activity and histopathological examination. The 30-day survival rate of mouse gamma-irradiated at 8 Gy failed to be improved by ATB pretreatment (100 mg/kg/day for 2 days). 6. These results provided evidence that ATB stimulated mEH and GST gene expression at early times and reduced the P4502C11 level in the absence of P4502E1 suppression. ATB was only partially effective in protecting the liver against toxicant-induced injury despite the presence of allylthio moiety in its chemical structure.

Mechanism underlying corticotropin-releasing hormone (CRH) triggered cytosolic Ca2+ rise in identified rat corticotrophs

1. The patch-clamp technique was used in conjunction with the fluorescent Ca2+ indicator indo-1 to measure simultaneously cytosolic Ca2+ concentration ([Ca2+]i) and membrane potential in single rat corticotrophs identified with the reverse haemolytic plaque assay. 2. Application of the adrenocorticotropin (ACTH) secretagogue, corticotropin-releasing hormone (CRH), triggered a sustained [Ca2+]i elevation and membrane depolarization. 3. The CRH action was mediated via the cAMP-dependent protein kinase cascade. Both the CRH-induced depolarization and [Ca2+]i elevation could be mimicked by extracellular application of the adenylate cyclase activator forskolin or the membrane-permeable cAMP analogue, 8-(4-chlorophenylthio)-adenosine-3',5'-cyclic monophosphate (8-CPT-cAMP). Intracellular adenosine cyclic 3',5'-(Rp)-phosphothioate (Rp-cAMPS), a protein kinase A inhibitor, abolished the CRH effects. 4. Voltage-clamp studies suggest that the CRH-triggered depolarization was due to the reduction of background K+ conductances. The CRH-sensitive current was Ca2+ independent and was insensitive to the K+ channel blockers tetraethylammonium (TEA) or 4-aminopyridine (4-AP), but could be partially inhibited by Ba2+. 5. The CRH-triggered steady-state depolarization stimulated extracellular Ca2+ entry via voltage-gated Ca2+ channels and raised [Ca2+]i. CRH failed to stimulate [Ca2+]i rise in cells that were voltage clamped at their resting potential. Removal of extracellular Ca2+ or inhibition of Ca2+ channels by Ni2+ abolished the [Ca2+]i rise. 6. Voltage-clamp studies of voltage-gated Ca2+ channels using Ba2+ as charge carrier show that approximately 90% of the channels were available for activation at the resting potential. CRH did not enhance the voltage-gated Ca2+ channels.

Lymph node negative invasive breast carcinoma 1 centimeter or less in size (T1a,bNOMO): clinicopathologic features and outcome

BACKGROUND

Patients with lymph node negative invasive breast carcinomas < or = 1 cm in size have a low recurrence rate and may be spared adjuvant therapy. Reliable prognostic features will help physicians design appropriate treatment for these patients.

METHODS

The clinicopathologic features, prognostic marker profiles, and clinical outcomes of 88 T1a,bN0M0 carcinomas in 87 patients who presented between 1975 and 1990 were studied. The size of each tumor was determined by direct measurement of histologic sections. The median follow-up was 7.8 years (range, 4-15 years). The characteristics of tumors diagnosed between 1975 and 1983 and between 1984 and 1990 were also compared.

RESULTS

Before 1984, the majority of patients presented with palpable mass lesions, whereas from 1984 on, more patients presented with mammographic abnormalities. However, no significant differences in the pathologic features of tumors were observed between the two periods. There were only 3 locoregional recurrences (3%) and 4 distant recurrences (5%). Palpable tumors had worse prognoses than mammographically detected lesions (P = 0.02). Histologic grade, lymphatic invasion, hormone receptors, Ki-67 antigen, and bcl-2 expression were significant univariate prognostic indicators. The small number of patients in the series precluded multivariate analysis. None of the 43 patients (49%) with tumors < or = 0.5 cm, or of histologic and nuclear Grade 1, or of favorable histologic types developed recurrences; and their outcomes were significantly better than those of other patients (P = 0.013). Tumors originally classified as T1b, but which exceeded 1 cm on review and were excluded from the study, had a significantly higher distant recurrence rate (23%) than bona fide T1a,b carcinomas (P = 0.03).

CONCLUSIONS

T1a,bN0M0 carcinomas have a low recurrence rate, especially those tumors < or = 0.5 cm, or of low histologic or nuclear grade, or of favorable histologic type. The high recurrence among patients with tumors initially understaged as T1a,b carcinoma underscores the importance of accurately determining tumor size.

Dopamine (D2) receptor regulation of intracellular calcium and membrane capacitance changes in rat melanotrophs

1. Indo-1 microfluorimetry and patch clamp techniques were used to study the decrease in cytosolic [Ca2+] ([Ca2+]i) caused by dopamine (D2) receptor activation and the calcium dependence of membrane capacitance changes in single rat melanotrophs. 2. [Ca2+]i decreased when extracellular calcium was removed or when the calcium channel blockers nickel (2 mM) or cadmium (100 microM) were applied by bath perfusion. 3. Quinpirole, a dopamine (D2) receptor agonist, reduced [Ca2+]i by 55 +/- 9 nM and hyperpolarized membrane potential by 29 +/- 9 mV simultaneously. 4. Quinpirole-induced [Ca2+]i decrease required deactivation of voltage-dependent calcium channels. Voltage clamping the membrane potential at -25 mV prevented the quinpirole-induced [Ca2+]i decrease. Nickel (2 mM) reduced [Ca2+]i without hyperpolarization and precluded additional [Ca2+]i decrease by quinpirole. 5. Membrane capacitance measurement of secretion rates in cells dialysed with buffered calcium solutions showed that secretion began at approximately 400 nM Cai2+. 6. Melanotrophs have IP3-sensitive calcium stores, but no caffeine-sensitive calcium stores. Calcium released from IP3-sensitive calcium stores also stimulated secretion. 7. Secretion in melanotrophs is modulated by protein kinase activators. cAMP (200 microM) enhanced secretion at [Ca2+]i > 1000 nM. Phorbol myristate acetate (PMA; 200 nM) enhanced secretion at [Ca2+]i < 400 nM, but not in the absence of calcium. 8. Dopamine receptor activation can reduce secretion by reducing the calcium influx through calcium channels with hyperpolarization of the membrane potential. However downregulation of either cAMP or protein kinase C activity may also contribute to the decrease in secretion.

Controversies in the treatment of ductal carcinoma in situ

In summary, certain subgroups of DCIS appear not to require radiation. Corroboration of these results from retrospective reviews and prospective trials is necessary to confirm the safety and efficacy of individualized treatment strategies. Even though the current standard of treatment is (1) lumpectomy with radiation therapy, (2) mastectomy, or (3) mastectomy with reconstruction, it is possible in the future to say that patients with low-grade DCIS (the exact criteria to be defined) may be eligible for breast conservation without radiation, and all patients with high-grade DCIS or perhaps low-grade DCIS with necrosis would be treated best by lumpectomy plus radiation. It is possible that a small subgroup of patients may be best treated by mastectomy, or perhaps, as the results of B-24 become available, by radiation therapy plus tamoxifen. The use of tumor markers such as c-erbB-2, cathepsin D, and NM 23 may help us to better define these subgroups, but much study is necessary before a definite treatment strategy is reached.

Male breast carcinoma: an evaluation of prognostic factors contributing to a poorer outcome

BACKGROUND

Although breast cancer in men is far less common than breast cancer in women, it is associated with a less favorable prognosis. Conventional histopathologic features and new prognostic markers were evaluated to explain the less favorable survival outcome.

METHODS

Forty-six consecutive male breast carcinomas were studied for size, histologic and nuclear grade, histologic subtype, presence of carcinoma in situ, nipple involvement, lymphovascular invasion, hormone receptor status, c-erbB-2 protein overexpression, and p53 protein accumulation. These findings were correlated with survival.

RESULTS

Of the 46 carcinomas, 4 were noninvasive and 42 were invasive. In the invasive carcinomas, the median patient age was 64 years, and the median tumor size was 2 cm. The predominant histologic patterns were invasive ductal (45%) and mixed invasive ductal and cribriform (28%). Most tumors were of low histologic and nuclear grades (histologic grades: I, 17%; II, 50%; III, 33%; nuclear grade: I, 12%; II, 44%; III, 44%). Of those surgically staged, 22 patients (60%) were lymph node positive and 15 patients (40%) were node negative. Stage at presentation was higher than in women (0, 10%; 1, 17%; 2, 50%; 3, 13%; 4, 10%). The estrogen and progesterone receptor status was positive in 76% and 83% of tumors, respectively. Lymphatic vessel invasion (63%) and nipple involvement (48%) were also more common than in women. True Paget's disease of the nipple was not seen; all cases with nipple ulceration were the result of direct tumor extension to the epidermis. Of the 17 tumors tested, 41% were c-erbB-2 positive and 29% were p53 positive. Survival analysis was limited by the relatively small cohort size. Five- and 10-year adjusted overall survival rates for invasive tumors were 76 +/- 7% and 42 +/- 9%, respectively. Skin and nipple involvement (P = 0.03) and c-erbB-2-positivity (P = 0.03) were significant predictors of adverse survival.

CONCLUSIONS

Male breast carcinoma presents in an advanced stage with less favorable survival, despite low histologic grade, high estrogen receptor content, and small size. Anatomic factors may have been responsible for the poor survival outcome (i.e., paucity of breast tissue and close tumor proximity to skin and nipple, facilitating dermal lymphatic spread and early regional and distant metastasis).

The role of immunocytochemical markers in the differential diagnosis of proliferative and neoplastic lesions of the breast

The differential expression of keratins in myoepithelial and epithelial cells of the breast makes immunohistochemical distinction of lesions an attractive possibility. High molecular weight keratin, 34BE12, is a monoclonal antibody that recognizes keratins 1, 5, 10, and 14. Because myoepithelial cells predominantly express keratins 5 and 14 and epithelial cells predominantly express keratins 8 and 18, it is natural to assume that 34BE12 may be a good marker of myoepithelial cells but not epithelial cells. However, recent studies of the breast have reported conflicting results. To determine the potential role of 34BE12 in the breast, we studied by immunohistochemistry 19 tubular carcinomas, 14 radial scars, two microglandular adenoses, and 9 sclerosing adenoses, using monoclonal antibodies to high molecular weight keratin, smooth muscle actin, type IV collagen, and antiserum to S100 protein. Actin was negative in all 19 (100%) tubular carcinomas, but it delineated the myoepithelial cells in 22 of 23 (95.6%) benign lesions of sclerosing adenosis and radial scars; it was also negative in microglandular adenosis. In comparison, epithelial cytoplasmic 34BE12 reactivity was seen in 3 of 19 (15.8%) tubular carcinomas, whereas myoepithelial cells failed to react in 4 of 23 (17.3%) benign conditions. Antiserum to S100 protein had a similar disadvantage of labeling both epithelial and myoepithelial cells with reactivity in 5 of 19 (26.3%) tubular carcinomas. In microglandular adenosis, the epithelial cells were strongly S100 protein positive and focally 34BE12 positive, but no staining was observed for actin. Type IV collagen staining outlined distinct basement membranes in microglandular adenosis and other benign conditions but not in tubular carcinomas. However, staining for type IV collagen requires enzymatic pretreatment and is difficult to perform, especially in sclerotic breast tissue. In conclusion, actin appears to be the most consistent and specific marker for distinguishing tubular carcinomas from other benign conditions, and type IV collagen has a contributory role, whereas 34BE12 is less valuable than in prostatic biopsies.

Angiogenesis in colorectal tumors: microvessel quantitation in adenomas and carcinomas with clinicopathological correlations

Angiogenesis is a crucial step in tumor growth and progression. Its quantitation by microvessel counting is of prognostic value in several types of malignancies. Scarce data are available on angiogenesis in gastrointestinal tumors. We studied 36 adenomas and 178 large bowel carcinomas to evaluate the onset of angiogenesis in colorectal tumorigenesis and to assess the prognostic significance of microvessel quantitation. Endothelial cells were immunostained with an anti-CD31 mAb; in each case three microscopic fields (x 200) with the highest number of microvessels were counted: the average value of the three fields was used to evaluate the significance of microvessel density (MVD). MVD of normal mucosa (41 cases) served as controls. MVD was 42 +/- 10 in the normal mucosa, 64 +/- 10 in adenomas, and 115 +/- 39 in carcinomas (normal versus adenomas, P < 0.001; adenomas versus carcinomas, P < 0.0001). The transitional mucosa adjacent to carcinomas displayed intermediate levels of MVD (89 +/- 23; P < 0.001 versus adenomas; P < 0.001 versus carcinomas). High MVDs were not associated with metastases, disease stage, and patient survival. The data indicate that angiogenesis is an early, critical step in colorectal tumorigenesis. MVD, however, does not provide significant prognostic information in colorectal cancer patients.

CDC25 phosphatases as potential human oncogenes

Cyclin-dependent kinases (CDKs) are activated by CDC25 phosphatases, which remove inhibitory phosphate from tyrosine and threonine residues. In human cells, CDC25 proteins are encoded by a multigene family, consisting of CDC25A, CDC25B, and CDC25C. In rodent cells, human CDC25A or CDC25B but not CDC25C phosphatases cooperate with either Ha-RASG12V or loss of RB1 in oncogenic focus formation. Such transformants were highly aneuploid, grew in soft agar, and formed high-grade tumors in nude mice. Overexpression of CDC25B was detected in 32 percent of human primary breast cancers tested. The CDC25 phosphatases may contribute to the development of human cancer.

p53 gene mutations, p53 protein accumulation and compartmentalization in colorectal adenocarcinoma

p53 accumulation may occur in the nucleus and/or cytoplasm of neoplastic cells. Cytoplasmic accumulation has been reported to be an unfavorable, but not established, prognostic indicator in colorectal cancer. Different types of p53 intracellular compartmentalization could depend either on p53 gene mutations or on the interaction with p53 protein ligands. The purposes of our study were (1) to assess whether the different patterns of p53 accumulation are selectively associated with p53 mutations and (2) to evaluate the clinical significance of p53 mutations in colorectal carcinomas. We evaluated p53 gene mutations in colorectal carcinomas. We evaluated p53 gene mutations in exons 5 through 8, by polymerase chain reaction and single-strand conformation polymorphism analysis; p53 accumulation and intracellular compartmentalization were detected immunocytochemically with the antibodies PAb1801 and CM1. p53 mutations were found in 74 of 126 carcinomas (59%). Nuclear p53PAb1801 accumulation was associated with p53 gene mutations (P < 0.001) whereas cytoplasmic p53 CM1 accumulation was more likely to occur with the wild-type p53 gene (P = 0.048). Overall, 112 carcinomas (89%) displayed p53 gene mutations and/or p53 accumulations of any type. p53 mutations were not correlated with important clinicopathological parameters and were not related to patient survival. Our data suggest that mechanisms other than mutations may also play a role in inhibiting p53 tumor-suppressing functions in colorectal carcinomas. Cytoplasmic p53CM1 accumulation frequently does not depend on p53 mutations.

The prevalence and clinical significance of chromogranin A and secretogranin II immunoreactivity in colorectal adenocarcinomas

Colorectal adenocarcinomas may display features of endocrine differentiation, shown by argyrophil stains and by the expression of endocrine markers such as chromogranin A. We investigated chromogranin A and secretogranin II immunoreactivity in a series of 208 carcinomas of the large bowel to assess the prevalence and clinical significance of endocrine differentiation. Tumors expressing endocrine markers were classified as low expressors (< than 1 immunoreactive tumour cell/mm2) and high expressors (> than 1 immunoreactive tumour cell/mm2). There were 33 (16%) carcinomas showing both chromogranin A and secretogranin II immunoreactivity: 11 tumours (5%) were high expressors. Endocrine differentiation was not related to the disease stage, tumour location, grade, DNA ploidy and p53 protein accumulation. In the entire series chromogranin A immunoreactivity did not provide prognostic information using univariate and multivariate analysis. A worse overall survival (P = 0.048) was demonstrated for the stage III patients with high expressor tumours, but there were only five patients in this group. The results of our investigation suggest that chromogranin A immunoreactivity is not a useful variable in the prognostic assessment of colorectal adenocarcinomas.

Hot flushes in men with pituitary adenoma

BACKGROUND

Hot flushes are common in menopausal women and also in men made acutely hypogonadal after orchiectomy or testicular injury. It is, however, an unusual symptom in patients with hypogonadism secondary to pituitary tumors.

METHODS

In evaluating the histories of men with hypogonadal state associated with nonfunctioning pituitary macroadenoma we were struck by the presence of hot flushes in four of them.

RESULTS

All four of the patients were hypogonadal with sexual dysfunction preoperatively. All had low gonadotropins and low testosterone levels with varying degrees of panhypopituitarism. All had successful transsphenoidal removal of tumors. None had endocrine improvement following surgery. All patients had improvement in sexual function and the hot flushes with administration of testosterone postoperatively.

CONCLUSIONS

Hot flushes are an uncommon presentation in men with pituitary adenoma. Perhaps the symptom will become more prominent if it is specifically questioned. We postulate that the cause of the flushing is related to nonsuppressed pulsatile secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus.

bcl-2 oncoprotein in colorectal hyperplastic polyps, adenomas, and adenocarcinomas

The bcl-2 gene is an oncogene that inhibits programmed cell death (apoptosis). We investigated by immunocytochemistry bcl-2 expression in normal colonic mucosa, hyperplastic polyps, adenomas, and adenocarcinomas of the large bowel. The purpose of the investigation was twofold; to assess the possible role of bcl-2 in colorectal tumorigenesis and to evaluate its clinical significance. The cases studied included 24 hyperplastic polyps, 49 adenomas, and 205 colorectal carcinomas. In both normal mucosa and hyperplastic polyps bcl-2 immunoreactivity was detected only in the proliferative cells of the colonic crypts. Conversely, bcl-2 immunoreactivity was noted in all adenomas irrespective of the degree of dysplastic change; it was diffuse in 84% of adenomas and focal in the remaining cases. In colorectal carcinomas bcl-2 expression was undetectable in 50% and focal (less than 50% immunostained neoplastic cells) in 38% of tumors. The remaining 12% of the carcinomas displayed diffuse (more than 50% immunostained neoplastic cells) bcl-2 immunoreactivity. In colorectal carcinomas bcl-2 expression was not correlated with relevant clinicopathologic parameters, including disease stage, tumor location and growth fraction, DNA ploidy, and p53 protein accumulation, and had no prognostic significance by univariate or multivariate analysis. These results suggest that bcl-2 oncoprotein may play a role in colorectal tumorigenesis, probably in the early phases of the adenoma-carcinoma sequence. bcl-2 expression in established tumors has no prognostic significance.

Ductal carcinoma in situ of the male breast

BACKGROUND

Ductal carcinoma in situ (DCIS) of the male breast is an uncommon disease, accounting for approximately 7% of all male breast carcinomas. Compared with invasive carcinomas of the breast, the prognosis associated with DCIS in men is excellent; however, clinical features, pathology, and treatment of this disease are not well defined in the literature.

METHODS

Records of 23 men with carcinoma of the breast treated at the Lahey Clinic from 1968 to 1991 were reviewed, revealing 4 patients with pure DCIS (17%). The reported management of DCIS in women is discussed in comparison with that of DCIS in men.

RESULTS

Of the four patients with DCIS, the presenting complaint was a retroareolar mass in three patients and a bloody nipple discharge in one patient. The pathologic subtype was papillary in one patient and intracystic papillary in three patients. Two patients were treated with partial mastectomy alone. Disease recurred locally as DCIS in both patients, requiring mastectomy at 30 and 108 months. No lymph node metastases were found in the three patients who underwent axillary dissection. All four patients were alive without disease at 133, 120, 36, and 32 months of follow-up, respectively.

CONCLUSIONS

Although the sample size was small, our patients and a review of the literature suggest that most DCIS in men is of the papillary type and that mastectomy without axillary dissection is the preferred treatment.

Cyclic GMP-dependent protein kinase activity in rat pulmonary microvascular endothelial cells

Cyclic GMP-dependent protein kinase (cGPK) activity was determined in rat pulmonary microvascular endothelial cells (RPMVEC) using cGMP-stimulated phosphorylation of BPDEtide and histone F2B substrates in the presence of PKI [peptide inhibitor of cAMP-dependent protein kinase (cAPK)]. RPMVEC cGPK activity was localized to the 100,000 x g cytosolic fraction. The EC50 for cGMP activation in the presence of PKI was 0.16 microM and H-89 inhibition under similar conditions showed an IC50 value of 0.16 microM. Anion-exchange chromatography of RPMVEC and rat lung cytosolic fractions showed separation of the cGMP-dependent from the cGMP-independent protein kinase activity and similar elution conductivities. Further, Western blots of RPMVEC active DEAE-Trisacryl fractions showed immunoreactivity using bovine Type I cGPK antiserum. Preliminary studies reveal six potential substrates phosphorylated by cGPK in RPMVEC. These studies describe an endothelial cell (EC) cGMP-receptor, cGPK, in addition to cGMP-activated (Type II) phosphodiesterase (PDE).

Cytoplasmic accumulation of p53 protein: an independent prognostic indicator in colorectal adenocarcinomas

BACKGROUND

Aberrations of the p53 gene (also known as TP53) frequently lead to the synthesis of mutant proteins that accumulate in the nuclei and/or cytoplasm of neoplastic cells. Intracellular p53 protein accumulation may be an unfavorable prognostic parameter in breast, lung, ovarian, gastric, and colorectal cancers. Specific classes of p53 gene mutations, assayed by characteristic subcellular p53 protein accumulation patterns, may be useful prognostic indicators.

PURPOSE

The prognostic value of nuclear and cytoplasmic p53 protein accumulation in the tumor cells of patients with colorectal carcinoma was studied.

METHODS

Antibodies PAb 1801 and CM1 were used for immunocytochemical assay of nuclear and cytoplasmic p53 protein accumulation in a retrospective series of colorectal carcinoma samples obtained from 206 patients who were followed for at least 5 years. Results were correlated with the following clinicopathologic parameters: patient sex and age; tumor site, stage, and grade; and DNA ploidy status of the tumors. Overall survival and disease-free survival were analyzed with the Kaplan-Meier method. Differences in distributions were analyzed using the Mantel-Cox method. Multivariate analysis was performed with the Cox proportional hazards model.

RESULTS

Immunostaining with PAb 1801 revealed nuclear p53 accumulation in 46% (95) of 206 cases, whereas CM1 immunostaining of 197 cases showed nuclear and cytoplasmic p53 accumulation in 33% (65 cases) and 50% (99 cases) of the cases, respectively. In univariate analysis, both nuclear p53PAb 1801 and cytoplasmic p53CM1 protein accumulations were significantly associated with poor overall survival (P = .0198 and P = .0017, respectively) and with disease-free survival (P = .004 and P = .0016, respectively). When patients were analyzed according to site of their tumors, nuclear p53PAb 1801 protein accumulation was statistically significant only in the right colon (P = .027), whereas cytoplasmic p53CM1 protein accumulation was statistically significant in the left colon and rectum (P = .0016). In multivariate analysis, only cytoplasmic p53CM1 protein accumulation was associated with poor overall survival and with disease-free survival (P = .006 and P = .002, respectively). With the addition of DNA ploidy status, however, cytoplasmic p53CM1 protein accumulation remained significant only for disease-free survival (P = .035). In patients with tumors of the left colon and rectum, cytoplasmic p53CM1 protein accumulation was the most significant prognostic indicator for overall survival (P = .007) and disease-free survival (P = .002) after disease stage.

CONCLUSION

Cytoplasmic p53CM1 protein accumulation, but not nuclear p53PAb 1801 protein accumulation, is an independent prognostic parameter in patients with colorectal carcinomas.

IMPLICATIONS

Cytoplasmic p53CM1 accumulation may be a useful indicator of patients at high risk for disease recurrence who may benefit from aggressive adjuvant therapy.