Epidemiology and prevention of bacterial infections in patients with hematologic malignancies

Bacterial infections are a serious complication of hematologic malignancies and the therapies used to treat them. Neutropenia can result from the malignancy itself or develop as a complication of chemotherapy and remains a major risk factor for the development of infections in these patients. In addition, the mechanical and chemotherapeutic interventions applied to patients with hematologic malignancies impose additional challenges to host defenses against bacterial invasion. The bacteria responsible for most infections in this patient population have continued to evolve as different therapeutic, preventive, and preemptive strategies are introduced into the armamentarium for leukemias, lymphomas, and myelomas. Both Gram-negative and Gram-positive pathogens have become increasingly resistant to available antimicrobial agents, in part due to the increasing use of agents, especially the fluoroquinolones, to prevent bacterial infections. This review addresses recent clinical developments in the epidemiology and prevention of bacterial infections in these unique populations of patients.     

Case Report: Congenital Radioulnar Synostosis and Its Embryological Correlation and Functional Assessment

Congenital radioulnar synostosis(CRS) is a rare anomaly and approximately 400 cases were reported worldwide so far. CRS is the failure of the longitudinal segmentation and the persistence of the cartilaginous anlage between the radius and ulna during the seventh week of development that results in a persistent bridge of tissue. Here we are discussing on a case of 25yrs old, male patient with bilateral congenital synostosis. On the left hand the pronation and supination movements are restricted completely where as on right side 10 degree of supination and 20 degree of pronation is possible. Radiologically in our patient synostosis is classified as type II variety by Wilkie(1914)1 classification and type IV by the Cleary and Omer classification(1985). The position of forearm was not found to be related to subjective functional limitation, or employment status. Main line of treatment is surgical mainly rotational osteotomy but is rarely indicated. Our patient is not able to rotate his forearm especially on the left side still he has no functional limitation so he has refused for the operative treatment. No study has objectively compared the preoperative functional limitation of the patients with their postoperative functional improvement in order to justify surgical intervention In the authors opinion the only major factor that is to be taken into consideration of operative treatment is functional limitation to the patient.     

Evaluation of the introduction of a standardised protocol for the staging and follow-up of colorectal cancer on resection rates for liver metastases

INTRODUCTION

In 2004, an audit in our unit demonstrated wide variation in liver resection rates for colorectal cancer (CRC) metastases within the cancer network. Subsequently, a network-wide CT-based follow-up and referral policy was introduced for all patients. A second audit was performed to assess the impact of the guidelines on liver resection rates.

SUBJECTS AND METHODS

Analysis of prospective liver resection database between 1997 and 2004 and after the introduction of standardised guidelines between January 2005 and April 2008.

RESULTS

A total of 362 patients underwent liver resection for CRC metastases between 1997 and 2008, 237 prior to the introduction of the referral guidelines and 125 after. Liver resection rates according to referring hospital varied from 0.92 to 2.32 per 100,000 population before guidelines were introduced. After 2005, resection rates from the four district hospitals standardised (1.68–1.84 per 100,000 population), but the central unit rate (Sheffield) remained significantly higher (2.67 per 100,000 population). No significant difference in 1-year disease-free survival between patients from Sheffield and the outlying hospitals was found (P = 0.553).

CONCLUSIONS

Introduction of a referral protocol standardised resection rates from the four district hospitals, but these remain lower compared to the specialist centre. The wide-spread adoption of a policy to discuss all patients with liver metastases at an advanced disease multidisciplinary team meeting, in the presence of hepatobiliary specialists, may further increase resection rates across the UK.     

Developing a Quality Screening Colonoscopy Referral System in Primary Care Practice: A Report from the National Colorectal Cancer Roundtable

The use of colonoscopy in colorectal cancer (CRC) screening has increased substantially in recent years. Media messages and changes in insurance reimbursement, as well as new screening guidelines from the American Cancer Society and the US Preventive Services Task Force, have contributed to this increase. Primary care providers (PCPs) are frequently responsible for making the recommendation and referral for screening. The process of successfully referring a patient for screening colonoscopy can be cumbersome and requires a coordinated effort between the PCP and the endoscopist. In recognition of the potential complexity of this process, the National Colorectal Cancer Roundtable has issued a report to describe the components of a quality screening colonoscopy referral system in primary care practice. The elements of a quality program include an optimal scheduling and referral system, the appropriate patient preparation information, consistent reporting and follow–up systems, and a detailed approach to dealing with special situations. CA Cancer J Clin 2010. © 2009 American Cancer Society, Inc.     

Causality and functional relevance of BRCA1 and BRCA2 pathogenic variants in non-high-grade serous ovarian carcinomas

The identification of causal BRCA1/2 pathogenic variants (PVs) in epithelial ovarian carcinoma (EOC) aids the selection of patients for genetic counselling and treatment decision-making. Current recommendations therefore stress sequencing of all EOCs, regardless of histotype. Although it is recognised that BRCA1/2 PVs cluster in high-grade serous ovarian carcinomas (HGSOC), this view is largely unsubstantiated by detailed analysis. Here, we aimed to analyse the results of BRCA1/2 tumour sequencing in a centrally revised, consecutive, prospective series including all EOC histotypes. Sequencing of n = 946 EOCs revealed BRCA1/2 PVs in 125 samples (13%), only eight of which were found in non-HGSOC histotypes. Specifically, BRCA1/2 PVs were identified in high-grade endometrioid (3/20; 15%), low-grade endometrioid (1/40; 2.5%), low-grade serous (3/67; 4.5%), and clear cell (1/64; 1.6%) EOCs. No PVs were identified in any mucinous ovarian carcinomas tested. By re-evaluation and using loss of heterozygosity and homologous recombination deficiency analyses, we then assessed: (1) whether the eight ‘anomalous’ cases were potentially histologically misclassified and (2) whether the identified variants were likely causal in carcinogenesis. The first ‘anomalous’ non-HGSOC with a BRCA1/2 PV proved to be a misdiagnosed HGSOC. Next, germline BRCA2 variants, found in two p53-abnormal high-grade endometrioid tumours, showed substantial evidence supporting causality. One additional, likely causal variant, found in a p53-wildtype low-grade serous ovarian carcinoma, was of somatic origin. The remaining cases showed retention of the BRCA1/2 wildtype allele, suggestive of non-causal secondary passenger variants. We conclude that likely causal BRCA1/2 variants are present in high-grade endometrioid tumours but are absent from the other EOC histotypes tested. Although the findings require validation, these results seem to justify a transition from universal to histotype-directed sequencing. Furthermore, in-depth functional analysis of tumours harbouring BRCA1/2 variants combined with detailed revision of cancer histotypes can serve as a model in other BRCA1/2-related cancers. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.     

Cost-effectiveness of targeted and tailored interventions on colorectal cancer screening use

BACKGROUND: Colorectal cancer (CRC) screening is cost-effective but underused. The objective of this study was to determine the cost-effectiveness of targeted and tailored behavioral interventions to increase CRC screening use by conducting an economic analysis associated with a randomized trial among patients in a large, racially and ethnically diverse, urban family practice in Philadelphia. METHODS: The incremental costs per unit increase were measured in individuals who were screened during the 24 months after intervention. Percent increase in screening was adjusted for baseline differences in the study groups. Each intervention arm received a targeted screening invitation letter, stool blood test (SBT) cards, informational booklet, and reminder letter. Tailored interventions incrementally added tailored messages and reminder telephone calls. RESULTS: Program costs of the targeted intervention were 42 dollars per participant. Additional costs of adding tailored print materials and of delivering a reminder telephone call were 150 dollars and 200 dollars per participant, respectively. The cost per additional individual screened was 319 dollars when comparing the no intervention group with the targeted intervention group. CONCLUSIONS: The targeted intervention was more effective and less costly than the tailored intervention. Although tailoring plus reminder telephone call was the most effective strategy, it was very costly per additional individual screened. Mailed SBT cards significantly boosted CRC screening use. However, going beyond the targeted intervention to include tailoring or tailoring plus reminder calls in the manner used in this study did not appear to be an economically attractive strategy.     

Cyclosporine as prophylaxis for graft-versus-host disease: a randomized study in patients undergoing marrow transplantation for acute nonlymphoblastic leukemia

Seventy-five patients, 13 to 49 years of age, with acute nonlymphoblastic leukemia in first remission were treated with cyclophosphamide, fractionated total body irradiation, and marrow transplantation from an HLA-identical sibling and randomized to receive either cyclosporine (CSP) (n = 36) or methotrexate (MTX) (n = 39) as prophylaxis for graft-v-host disease (GVHD). All patients engrafted, and 22 who were given CSP and 21 who were given MTX, are alive at 20 to 47 (median, 35) months (P = .5). Engraftment as assessed by granulocyte recovery (P less than .0005) and platelet transfusion requirement (P = .01) was faster in patients on CSP. Twelve patients (33%) on CSP and 22 (56%) on MTX developed acute GVHD of grades II through IV (P = .07) and 15 of 30 on CSP and 14 of 32 on MTX that were at risk developed chronic GVHD. The most frequent causes of death were interstitial pneumonitis and marrow relapse of leukemia, which occurred with similar frequency in both groups. Beneficial effects observed in patients on CSP included less severe mucositis and shorter duration of hospitalization; adverse effects included renal function impairment and hypertension. These data confirm that CSP is a useful immunosuppressant in patients undergoing marrow transplantation but fail to show a significant improvement in survival as compared with the standard regimen of MTX.     

Function of wild-type or mutant Rac2 and Rap1a GTPases in differentiated HL60 cell NADPH oxidase activation

Studies of neutrophil nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation in a cell-free system showed that the low molecular-weight guanosine triphosphatase (GTPase) Rac was required, and that Rap1a may participate in activation of the catalytic complex. Full-length posttranslationally modified Rac2 was active, whereas only the 1-166 truncated form of Rap1a was functional in the cell-free system, and thus, clarification of the function of Rap1a and Rac2 in intact human phagocytes is needed to provide further insight into their roles as signal transducers from plasma membrane receptors. In the present studies, oligonucleotide-directed mutagenesis was used to introduce a series of mutations into human rap1a or rac2 in the mammalian expression vector pSR alpha neo. HL60 cells transfected with wild-type or mutated rac2 or rap1a cDNA constructs and control HL60 cells transfected with the pSR alpha neo vector containing no inserted cDNA were selected in G418-containing media, then subclones were isolated. Compared with the parent HL60 cells, each of the stable transfected cell lines differentiated similarly into neutrophil-like cells and expressed comparable levels of NADPH oxidase components p47- phox, p67-phox and gp91-phox. The differentiated vector control cell line produced O2. in response to receptor stimulation at rates that were not significantly different from parent HL60 cells. O2-. production by differentiated cell lines expressing mutated N17 Rap1a or N17 Rac2 dominant-negative proteins was inhibited, whereas O2-. production by the subline overexpressing wild-type Rap1a was increased by fourfold. O2-. production by the differentiated cell line expressing GTPase-defective V12 Rap1a was also significantly inhibited, a finding that is consistent with a requirement for cycling between guanosine diphosphate- and GTP-bound forms of Rap1a for continuous NADPH oxidase activation in intact neutrophils. A model is proposed in which Rac2 mediates assembly of the p47 and p67 oxidase components on the cytosolic face of the plasma membrane via cytoskeletal reorganization, whereas Rap1a functions downstream as the final activation switch involving direct physical interaction with the transmembrane flavocytochrome component of the NADPH oxidase.     

Abnormalities of iron metabolism and erythropoiesis in vitamin E- deficient rabbits

Rabbits fed a vitamin E-deficient diet developed severe muscular dystrophy in 3-4 wk, but they did not become anemic. Nevertheless, reticulocyte counts increased in deficient rabbits (3.2%) compared to control rabbits (0.9%), and erythroid hyperplasia was evident in the bone marrow. Comparing deficient rabbits to controls, the plasma iron concentration was lower (134.4 versus 206.6 microgram/dl); the TIBC was higher (335.9 versus 228.3 microgram/dl); the whole blood protoporphyrin concentration was higher (131.6 versus 81.7 microgram/dl); and the total iron content was lower in spleen (71 versus 153 microgram), higher in skeletal muscle (4956 versus 3054 microgram), and unchanged in bone marrow, liver, and heart. Studies of iron absorption and excretion using 59Fe showed no abnormalities in deficient rabbits. There were abnormalities of ferrokinetics, however. The half-time of disappearance of 59Fe was shorter (100.6 versus 169.4 min), the plasma iron turnover was greater (1.25 versus 0.95 mg/dl blood/day), and the reappearance of 59Fe in circulating erythrocytes at day 9 was greater (77.2% versus 57.2%) in deficient rabbits. Anemia induced by phlebotomy accentuated the abnormal iron metabolism of deficient rabbits, and the animals were unable to correct the anemia. These findings show that vitamin E deficiency in rabbits causes abnormal erythropoiesis associated with abnormal iron metabolism and sequestration of iron in skeletal muscle.