The Pathologic Spectrum of Bone Marrow Involvement by Double- and Triple-hit Lymphomas

Introduction/Objective

B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements (double- and triple-hit lymphomas, DHL/THL) are a distinct entity due to shared biology and aggressive behavior, exhibiting poor outcomes with standard therapies. While pathologic features of DHL/THLs in primary sites have been well described, little information is available regarding the clinicopathologic features of bone marrow involvement by this entity.

Methods/Case Report

Files were searched from 2010-2020 for all DHL/THLs. Since mid-2016, all aggressive B-cell lymphomas were reflexed to DHL/THL FISH testing. Prior to that, criteria for performing FISH varied. Clinical and laboratory data were obtained through chart review. Both BM and primary diagnostic specimens were reviewed when possible.

Results (if a Case Study enter NA)

There were 46 DHL/THL cases with initial staging BM evaluations, of which 13 (28%) were positive for DHL/THL; 11 were available for review (5F:6M; 28-95 years). All patients with positive BMs were stage 3 or 4 irrespective of the BM findings. Lymphoma cytology in positive BMs was blastoid in 6, large cell in 2, and high grade, NOS in 3. The cytology in primary tissues was not significantly associated with the rate of marrow involvement. PB smears were available for 9/11 BM(+) cases; of these, 6 (66.7%) had circulating lymphoma cells in the blood, ranging from rare to greater than 40% lymphoma cells (median, 4%). Lymphoma cells with cytoplasmic vacuoles were present in 5 cases (45%). No BM infiltrates had a starry-sky appearance. Infiltration patterns included diffuse (3), diffuse and interstitial (3), and interstitial (3). One exhibited only rare, scattered lymphoma cells in the aspirate and core biopsy, and another with large cell morphology showed random focal (nodular) and focally paratrabecular infiltration. The proliferation index in the marrow infiltrates ranged from 50% to >90% (median, 65%). Flow cytometry was positive in 9 of 10 cases; the single negative study was from an outside institution

Conclusion

Our study demonstrates 28% of DHL/THLs show BM involvement at diagnosis. Notably, the peripheral blood was involved in 2/3 of cases with marrow infiltration (13% of total cases), ranging from rare circulating cells to frank leukemic involvement. Cytologically, the marrow infiltrates were predominantly blastoid or high grade NOS. Marrow infiltrates generally displayed leukemic rather than lymphomatous patterns of involvement.

Comparison of the Institute for Credentialing Excellence Multi-Organization Survey of Certificants

Introduction/Objective

The Institute for Credentialing Excellence (ICE) conducted a study to measure the value that credential holders place on certification, collecting survey data from a large sample of more than 12,000 credential holders representing six organizations (4 of which were healthcare). In May of 2019, ASCP BOC sent the survey to 47,384 individuals certified within the last 5 years. Of those who received the survey; 2,038 completed the 80 required questions. A comparison of survey data provided an overview of the top five differences in the full survey data (n=9,407) and the data from respondents credentialed by ASCP BOC (n = 2,038 or 22% of full survey respondents) and highlighted the primary reasons individuals pursue certification.

Methods/Case Report

This survey sought to define certificants’ attitudes toward and experiences with certification. Survey questions were grouped by four primary subject areas:

The Value of Certification for Respondents’ Professions

The Value of Certification for Employers

The Value of Certification Outside the U.S. and Canada

The Value of Certification for Certificants

- Responses of themed queries of full survey data and BOC survey data were viewed side by side and averages, standard deviations and medians were calculated. The top 5 items indicating the highest difference from the full survey data results were highlighted.

- Ranked primary motivational factors for the pursuit of certification were viewed side-by-side.

Results (if a Case Study enter NA)

Based on a side-by-side comparison of full survey data and BOC survey data, only minor differences were noted with the exception of the question pertaining to the perceived value of recertification. Both differences and items of agreement were highlighted.

The top 10 reasons for seeking certification were the same amongst both the full survey and ASCP BOC survey respondents, with minor differences in priority order.

Conclusion

With the exception of the question regarding the value of recertification, discrepancies noted were minor. On most questions pertaining to the various benefits of certification, a majority of respondents gave a positive response about certification and its relationship to beneficial outcomes for their professions, employers, or themselves. It is clear that certificants place a high value on certification and believe that certification provides a number of valuable benefits.

Reducing IV-contaminated blood specimens in the clinical laboratory: A Quality Improvement Project

Introduction/Objective

Preanalytical errors constitute the most common errors in the laboratory, with improper specimen collection accounting for many errors. In our laboratory, we had a sentinel event related to repeated deletions of suspected IV-contaminated draws, and herein report our quality improvement project (QIP) to reduce deleted test results and IV-contaminated specimens.

Methods/Case Report

Our QIP initiated with creating a core-lab task force. Several interventions were launched: (A) policy/definition standardization, (B) nursing IV-line/cathedar in-services, (C) in-services on deleting test results and identifying IV-contamination, (D) policy updates to reflect no deletions without evidence of IV-contamination, and (E) mitigation steps requiring supervisory approval for result deletions. We measured: patient safety events (PSRs); RECOLLECTION comment usage and efficacy (disclaimer attached to results thought to be IV-contaminated, requesting recollection); and mitigation failures. Efficacy of the comment usage was measured by comparing subsequent collections to the original and determining likelihood of IV-contamination (contaminated, not contaminated, and unsure). Prior to the QIP, lab practice was to delete suspected IV-contaminated results and those requested by the care team.

Results (if a Case Study enter NA)

PSRs attributable to IV-contamination dropped from 47/mo. (time 0) to 18/mo. over an 11-month period (min-8/mo.; max-64/mo.), with the greatest decrement seen following intervention C. The RECOLLECTION comment was attached to 38 results (0.06% of total accessions) at the start and 73 results (0.12% of total accessions) at time 11 mos. and showed greatest increase in use immediately prior to interventions C and D (approximately 3-fold increase). At time 0, 54% of RECOLLECTION comments were deemed contaminated and 31% were not; at time 11mos., 74% (50/68) were contaminated and 24% (16/68) were not. Mitigation failures numbered 5/mo. initially and 1/mo. at time 11 mos.

Conclusion

With multiple educational and supervisory interventions, we demonstrate a reduction in PSRs attributable to IV-contamination collections at our hospital. Use of cautionary disclaimers was overall minimal and appropriately used.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Diabetes-related major lower limb amputation incidence is strongly related to diabetic foot service provision and improves with enhancement of services: peer review of the South-West of England

AIMS

To investigate the relationship between high diabetes-related lower limb amputation incidence and foot care services in the South-West region of England.

METHODS

The introduction of 10 key elements of foot care service provision in one area of the South-West resulted in stabilization of foot ulcer incidence and sustained reduction in amputation incidence from 2007. Services introduced included administrative support, standardized general practice foot screening, improved community podiatry staffing, hospital multidisciplinary foot clinics, effective care pathways, availability of an orthotist and audit. Peer reviews of the region's diabetes foot care services were undertaken to assess delivery of these service provisions and compare this with major amputation incidence in other regions with data provided by Yorkshire and Humber Public Health Observatory Hospital Episode Statistics. Recommendations were made to improve service provision. In 2015 changes in service provision and amputation incidence were reviewed.

RESULTS

Initial reviews in 2013 showed that the 3-year diabetes-related major amputation incidence correlated inversely with adequate delivery of diabetes foot care services (P=0.0024, adjusted R² =0.51). Repeat reviews in 2015 found that two or more foot care service improvements were reported by six diabetes foot care providers, with improvement in outcomes. The negative relationship between major amputation incidence and service provision remained strong both in the period 2012-2015 and in the year 2015 only (P ≤0.0012, adjusted R² =0.56, and P= 0.0005, R² =0.62, respectively).

CONCLUSIONS

Major diabetes-related lower limb amputation incidence is significantly inversely correlated with foot care services provision. Introduction of more effective service provision resulted in significant reductions in major amputation incidence within 2 years. Failure to improve unsatisfactory service provision resulted in continued high amputation incidence.

Anemia increases the risk of renal cortical and medullary hypoxia during cardiopulmonary bypass

Introduction:

Anemia is an independent predictor of acute kidney injury (AKI) following cardiopulmonary bypass (CPB), possibly due to inadequate renal oxygen delivery. The objective of this study was to investigate the effects of CPB and anemia on tissue oxygen tension (pO2) and blood flow in the renal cortex and medulla.

Methods:

Rats (n=6/group) underwent 1hr of normothermic cardiopulmonary bypass (CPB), with target hemoglobin concentrations (Hb) of 10g/dL (CPB) or 6.5g/dL (anemia-CPB). Renal blood flow (RBF) and tissue PO2 were measured before, during and after 1hr of CPB. To confirm the observed differences in renal cortical and medullary PO2, HIF-1α (ODD) luciferase mice were exposed to 8% O2 (hypoxia) and HIF-1α dependent luminescence was measured in the renal cortex and medulla (n=5).

Results:

Renal tissue PO2 values decreased initially and returned towards baseline, however, values at the end of CPB. Anemia-CPB resulted in a significant increase in both renal cortical and medullary blood flow, PO2 remained significantly reduced throughout anemia-CPB. Renal medullary HIF-1α-dependent luminescence confirmed a greater degree of hypoxia in the renal medulla.

Discussion:

During CPB, renal O2 delivery was transiently jeopardized, but recovered after 1hr. Anemia-CPB resulted in a dramatic and sustained reduction in renal cortical and medullary PO2, which suggests an increased risk of renal hypoxic injury with anemia.

Conclusion:

The clear difference in the degree of hypoxia in the renal cortex and medulla may be useful in understanding the progress of medullary hypoxia during CPB with anemia and the potential development of AKI. Further studies should aim at identifying early markers of medullary hypoxia and potential agents that may decrease the work and O2 consumption in the renal medulla to reduce the risk of hypoxic damage during CPB and anemia.

Education on physical restraint reduction in dementia care: a review of the literature

Dementia is a priority area for all countries as populations age and dementia prevalence increases. The use of physical restraint is a possible clinical practice for persons with dementia across settings when behaviours indicate a perceived need. Indeed, this may be the first choice in practice, occurring in part because of lack of education, safety concerns, perceived costs and staffing issues. This article reviews the literature on the issues surrounding, and use of, physical restraint for people with dementia, highlighting the rationales for use and the benefits and barriers to physical restraint. Recommendations include the importance of education and policy to reduce or eliminate physical restraint of persons with dementia to overcome identified barriers at the individual, cultural and organizational levels. An educational programme from the literature review is proposed specific to the reduction or elimination of physical restraint.

Construction of a Bacteriophage-Resistant Derivative of Lactococcus lactis subsp. lactis 425A by Using the Conjugal Plasmid pNP40

Lactococcus lactis subsp. lactis 425A is an atypical strain which excretes a high concentration of alpha-acetolactate when grown in milk. The conjugative lactococcal plasmid pNP40, which encodes phage and nisin resistance, was introduced to strain 425A by conjugation, using resistance to phage and nisin as a selection. No phage-nisin resistance mutants were encountered. Transconjugants display complete resistance at both 21 and 39 degrees C to those phage previously identified as lytic for 425A. Transconjugants lose their resistance characteristics when spontaneously cured of pNP40. The commercially important property of 425A-production of high levels of alpha-acetolactic acid-is unaffected by the presence of pNP40.

Storage of strain-specific rat blood limits cerebral tissue oxygen delivery during acute fluid resuscitation

BACKGROUND

The effect of blood storage on tissue oxygen delivery has not been clearly defined. Some studies demonstrate reduced microvascular oxygen delivery, whereas others do not. We hypothesize that storage of rat blood will limit its ability to deliver oxygen to cerebral tissue.

METHODS

Anaesthetized rats underwent haemorrhage (18 ml kg(-1)) and resuscitation with an equivalent amount of fresh or 7 day stored strain-specific whole blood. Arterial blood gases, co-oximetry, red cell counts and indices, and blood smears were performed. Hippocampal tissue oxygen tension (PBr(O2)), regional cerebral blood flow (rCBF), and mean arterial pressure (MAP) were measured before and for 60 min after resuscitation (n=6). Data [mean (SD)] were analysed by anova.

RESULTS

After 7 days, there was a significant reduction in pH, Pa(O2), an increase in Pa(CO2), but no detectable plasma haemoglobin in stored rat blood. Stored red blood cell morphology demonstrated marked echinocytosis, but no haemolysis in vitro. MAP and PBr(O2) in both groups decreased after haemorrhage. Resuscitation with stored blood returned MAP [92 (SD 16) mm Hg] and PBr(O2) [3.2 (0.7) kPa] to baseline, whereas rCBF remained stable [1.2 (0.1)]. Resuscitation with fresh blood returned MAP to baseline [105 (16) mm Hg] whereas both PBr(O2) [5.6 (1.5) kPa] and rCBF [1.9 (0.4)] increased significantly (P<0.05 for both, relative to baseline and stored blood group). There was no evidence of haemolysis in vivo.

CONCLUSIONS

Although resuscitation with stored blood restored cerebral oxygen delivery to baseline, fresh blood produced a greater increase in both PBr(O2) and rCBF. These data support the hypothesis that storage limits the ability of RBC to deliver oxygen to brain tissue.

Differentiation of Candida albicans from non-albicans yeast directly from blood cultures by Gram stain morphology

Clusters of pseudohyphae are commonly seen on Gram stain of blood cultures from patients with Candida albicans fungemia. Whether this morphologic feature is useful for differentiating C. albicans from other yeasts has not previously been systematically evaluated. Yeast morphology on Gram stain of blood cultures from consecutive patients with fungemia detected by the Bactec automated blood culture system was prospectively assessed and correlated with the final culture-based yeast identification. The distribution of yeast in 60 consecutive patients with fungemia included Candida spp. (C. albicans 43%, Candida glabrata 28%, Candida parapsilosis 8%, Candida krusei 7%, Candida tropicalis 5%, Candida dubliniensis 2%, and Candida lusitaniae 2%), Rhodotorula mucilaginosa 2%, and Cryptococcus neoformans 3%. Upon analysis of the first positive blood culture bottle per patient, the presence of clustered pseudohyphae on Gram stain had a sensitivity, specificity, positive predictive value, and negative predictive value of 85, 97, 96, and 89%, respectively, for C. albicans. The sensitivity and specificity of aerobic vs Myco/F blood culture bottles were 96 and 95% vs 25 and 100%, p < 0.001, respectively. Inter-rater agreement for ten separate observations among five reviewers was 100%. The presence of pseudohyphae clusters by Gram stain of blood cultures is useful in distinguishing C. albicans from non-albicans yeast. Additional studies are necessary to determine the clinical impact of these findings and their validity with other blood culture systems.

IpaC from Shigella and SipC from Salmonella possess similar biochemical properties but are functionally distinct

Invasion plasmid antigen C (IpaC) is secreted via the type III secretion system (TTSS) of Shigella flexneri and serves as an essential effector molecule for epithelial cell invasion. The only homologue of IpaC identified thus far is Salmonella invasion protein C (SipC/SspC), which is essential for enterocyte invasion by Salmonella typhimurium. To explore the biochemical and functional relatedness of IpaC and SipC, recombinant derivatives of both proteins were purified so that their in vitro biochemical properties could be compared. Both proteins were found to: (i) enhance the entry of wild-type S. flexneri and S. typhimurium into cultured cells; (ii) interact with phospholipid membranes; and (iii) oligomerize in solution; however, IpaC appeared to be more efficient in carrying out several of the biochemical properties examined. Overall, the data indicate that purified IpaC and SipC are biochemically similar, although not identical with respect to their in vitro activities. To extend these observations, complementation analyses were conducted using S. flexneri SF621 and S. typhimurium SB220, neither of which is capable of invading epithelial cells because of non-polar null mutations in ipaC and sipC respectively. Interestingly, both ipaC and sipC restored invasiveness to SB220 whereas only ipaC restored invasiveness to SF621, suggesting that SipC lacks an activity possessed by IpaC. This functional difference is not at the level of secretion because IpaC and SipC are both secreted by SF621 and it does not appear to be because of SipC dependency on this native chaperone as coexpression of sipC and sicA in SF621 still failed to restore detectable invasiveness. Taken together, the data suggest that IpaC and SipC differ in either their ability to be translocated into host cells or in their function as effectors of host cell invasion. Because IpaB shares significant sequence homology with the YopB translocator of Yersinia species, the ability for IpaC and SipC to associate with this protein was explored as a potential indicator of translocation function. Both proteins were found to bind to purified IpaB with an apparent dissociation constant in the nanomolar range, suggesting that they may differ with respect to effector function. Interestingly, whereas SB220 expressing sipC behaved like wild-type Salmonella, in that it remained within its membrane-bound vacuole following entry into host cells, SB220 expressing ipaC was found in the cytoplasm of host cells. This observation indicates that IpaC and SipC are responsible for a major difference in the invasion strategies of Shigella and Salmonella, that is, they escape into the host cell cytoplasm. The implications of the role of each protein's biochemistry relative to its in vivo function is discussed.

Ras pathway signals are required for notch-mediated oncogenesis

The Notch genes of C. elegans, Drosophila melanogaster and vertebrates encode receptors responsible for cell fate decisions during development. These Notch receptors and their ligands, Delta and Jagged, have been implicated in several human diseases. Truncated, constitutively active mutant forms of the Notch receptor appear to be involved in human T-cell leukemia, mammary carcinomas in mice, and a tumorous germline phenotype in C. elegans. Since activated Notch induces solitary tumors in transgenic mice, it is highly likely that collaborating genetic events are required for tumor formation. We have assessed four signal transduction pathways to determine which might play additional roles in malignant transformation in concert with activated Notch4. Our results suggest that transformation by Notch does not, as might have been expected, depend on the Src-like kinases Lck and Fyn, nor upon signals from protein kinase A and C (PKA, PKC). Rather, transformation by Notch requires active signals from the Erk/MAP kinase and PI-3 kinase pathways downstream of Ras. Oncogene (2000) 19, 4191 - 4198

Feedback-controlled laser-mediated cartilage reshaping

OBJECTIVE

To demonstrate feedback-controlled laser-mediated cartilage reshaping using dynamic measurements of tissue optical properties and radiometric surface temperatures.

DESIGN

Flat cartilage specimens were reshaped into curved configurations using a feedback-controlled laser device.

MATERIALS

Fresh porcine nasal septum, stripped of perichondrium and cut into uniform strips (25 x 10 x 1.5-2.1 mm) with a custom guillotine microtome.

INTERVENTIONS

Cartilage specimens secured in a cylindrical reshaping jig (2.5 cm in diameter) and irradiated with an Nd:YAG laser (lambda = 1.32 microns, 25 W/cm2, 50-Hz pulse repetition rate). During laser irradiation, radiometric surface temperature was measured along with changes in forward-scattered light from a diode probe laser (lambda = 650 nm, 5 mW), using a lock-in detection technique. Sequential irradiation of the specimen outer surface was made (3 laser passes). Characteristic changes in tissue temperature and light-scattering signals were used to terminate laser irradiation.

RESULTS

Effective reshaping was accomplished for both thin (1.5-mm) and thick (2.1-mm) specimens. Following reshaping, specimens were stored in saline solution at 4 degrees C for 21 days. No return to the original flat configuration was noted during this period.

CONCLUSIONS

The prototype device effectively reshapes flat native porcine cartilage into curve configurations. The use of optical and thermal signals provides effective feedback control for optimizing the reshaping process.

Dlx-5 in limb initiation in the chick embryo

Dlx-5 is a vertebrate homolog of the Drosophila Distal-less gene, one of the first genetic signals for limb formation in the fly. In the present study we have explored the possible role of Dlx-5 in limb initiation in the chick embryo. At stage 14 which is well before the initial formation of limb buds Dlx-5 is highly and specifically expressed in the ectoderm of the presumptive wing and leg forming regions of the lateral plate, but not in the intervening non-limb forming prospective flank. Thus, Dlx-5 expression distinguishes the limb-forming territories prior to limb budding, and is one of the first molecular markers of vertebrate limb initiation. Furthermore, Dlx-5 expression is induced in the non-limb-forming flank within 12 hours after implantation of an FGF2-soaked bead, a procedure that results in the induction of an ectopic limb. The rapid induction of Dlx-5 expression in response to a signal which ultimately leads to supernumerary limb formation is consistent with a role for Dlx-5 in limb initiation. We have also examined the expression of Dlx-5 in the limb buds of amelic limbless mutant chick embryos, which undergo normal limb formation but do not form an AER and thus fail to undergo further outgrowth. Dlx-5 is transiently expressed by the ectoderm of emergent limbless limb buds, consistent with a role for Dlx-5 in limb initiation. Together, our results suggest that Dlx-5 may be involved in the specification of the limb territories of the lateral plate, and in the initial formation of the limb bud from these regions. Dev Dyn 1999;216:10-15.

The effects of amperozide on cocaine-induced social withdrawal in rats

Cocaine decreases social interactions in both humans and animals, but it is not known whether the drugged animal withdraws from an undrugged conspecific, the undrugged conspecific avoids the drugged animal, or a combination of these two factors occurs. In the first experiment, the source of cocaine-induced social withdrawal was determined using a tether paradigm, in which the movement of one of the rats was restricted to one half of the observation chamber, such that the freely moving rat had the option of escaping social interactions. There were decreases in social interactions in the condition in which both rats were freely moving, and in the condition in which the undrugged rat was tethered, but not when the drugged rat was tethered and could not escape social contact. A second experiment was conducted to test the efficacy of the potent serotonin receptor antagonist, amperozide, in attenuating cocaine-induced social withdrawal using the condition in which the drugged rat was freely moving. Either amperozide (1.0, 3.0, and 5.0 mg/kg) or saline vehicle was injected into rats 1 h before receiving a 30.0 mg/kg cocaine dose. Cocaine decreased social interactions. Amperozide restored social interactions to near control levels and elevated social interactions in the animals treated with saline vehicle.

Reconceptualizing rigour: the case for reflexivity

This paper is a critical review of recent discussions of rigour in nursing research. We will argue that 'borrowing' evaluation criteria from one paradigm of inquiry and applying them to another is problematic. We attempt to map the 'rigour' field and add a dimension to the existing debate about rigour and qualitative research through inclusion of reflexivity guided by philosophical hermeneutics. We describe reflexivity and appeal to writers to incorporate a reflexive account into their research product by signposting to readers 'what is going on' while researching. We contend that researchers bring to the research product, data generated, a range of literature, a positioning of this literature, a positioning of oneself, and moral socio-political contexts. We suggest that reflexive research is characterized by ongoing self-critique and self-appraisal and that the research product can be given shape by the politics of location and positioning. We emphasize that in the creation of a text (the research product) it is desirable that the researcher be a skilled writer. Finally we claim that if the research product is well signposted, the readers will be able to travel easily through the worlds of the participants and makers of the text (the researchers) and decide for themselves whether the text is believable or plausible (our terms for rigour).

Patterns of X chromosome inactivation in sporadic basal cell carcinomas: evidence for clonality

BACKGROUND

Some basal cell carcinomas (BCCs) contain genetic mutations, suggesting that the lesion is composed of a monoclonal population of cells. Clonality, a distinguishing feature of neoplasia, can be inferred by referencing clonal markers such as the pattern of X chromosome inactivation. The X-linked human androgen receptor gene (HUMARA; GenBank) contains a polymorphic DNA marker that reliably illustrates the pattern of X chromosome inactivation in a tissue.

OBJECTIVE

Our purpose was to determine the clonality of sporadic BCCs by examining patterns of X chromosome inactivation.

METHODS

The patterns of X chromosome inactivation in paired samples of normal skin and sporadic BCCs from 24 women were compared by means of the HUMARA gene assay.

RESULTS

All samples from normal skin displayed random X chromosome inactivation, consistent with lyonization. In 15 of 25 tumor samples (60%), nonrandom X chromosome inactivation was detected, consistent with monoclonality.

CONCLUSION

At least some sporadic BCCs are composed of a monoclonal population of cells, strengthening the contention that a collection of mutations confers a growth advantage to this epithelial lesion.

The effects of raclopride on vacuous jaw movements in rats following acute administration

Classic neuroleptics produce a syndrome of vacuous jaw movements in rats, whereas atypical neuroleptics like clozapine do not. The present study compared the effects of repeated administration of raclopride, clozapine, haloperidol, or vehicle on vacuous jaw movements in rats over a 4-week period. Rats received an IP injection of drug once a day. On days 1, 8, 15, and 29 the rats were observed for a 5-min period by two trained observers who recorded their vacuous jaw movements. The dose-response curves at which each drug produced vacuous jaw movements are presented and discussed in terms of their predictive capabilities of early onset extrapyramidal side effects.

Clonality of basal cell carcinoma--molecular analysis of an interesting case

Tumor cells represent a single clone of cells that have undergone a series of mutations in genomic DNA. This process, known as clonal evolution, is a distinguishing feature of cancer. The human androgen receptor gene (HUMARA; GenBank) contains a highly polymorphic cytosine-adenine-guanine trinucleotide repeat that can be used to determine clonality by depicting X chromosome inactivation patterns. Random X chromosome inactivation is consistent with polyclonality; nonrandom X chromosome inactivation indicates a clonal population of cells. Basal cell carcinoma (BCC) demonstrates an atypical growth pattern in that it grows slowly, rarely metastasizes, and is rarely lethal. Whether this tumor results from the accumulation of mutations in a single cell with subsequent clonal expansion or reflects a polyclonal response by a group of cells to a growth stimulus is unknown. To provide further insight into the molecular events characterizing BCCs, we determined the clonal origin of five modular BCCs from a female patient by analyzing X chromosome inactivation patterns at the HUMARA locus. All tumors demonstrated a nonrandom pattern of X chromosome inactivation, consistent with monoclonal proliferation. These findings provide strong genetic evidence that sporadic BCCs develop by clonal evolution and support the contention that a series of mutations in a single cell is responsible for the altered growth state seen in these transformed epithelial cells.

Cytochrome P4501A1 and glutathione S-transferase (M1) genetic polymorphisms and postmenopausal breast cancer risk

Polycyclic aromatic hydrocarbons, possible human breast carcinogens, are metabolized by cytochrome P4501A1 (CYP1A1) and glutathione S-transferase (GSTM1). A CYP1A1 polymorphism (isoleucine to valine substitution in exon 7) or the null allele for GSTM1 may affect the mutagenic potential of polycyclic aromatic hydrocarbons. We examined polymorphisms in GSTM1 and CYP1A1 in relation to breast cancer risk. Included were 216 postmenopausal Caucasian women with incident breast cancer and 282 community controls. DNA analyses suggested no increased breast cancer risk with the null GSTM1 genotype [odds ratio (OR) = 1.10; CI, 0.73-1.64], although there was some indication that the null genotype was associated with risk among the youngest postmenopausal women (OR = 2.44; CI, 0.89-6.64). Slightly elevated risk was associated with the CYP1A1 polymorphism (OR = 1.61; CI, 0.94-2.75) and was highest for those who smoked up to 29 pack-years (OR = 5.22; CI, 1.16-23.56). Statistical power to detect an effect may be limited by small numbers, and larger sample sizes would be required to corroborate these suggestive findings.

Characterization of plasmid-encoded citrate permease (citP) genes from Leuconostoc species reveals high sequence conservation with the Lactococcus lactis citP gene

The citrate permease determinant (citP) in several Leuconostoc strains was demonstrated to be plasmid encoded by curing experiments and hybridization studies with a DNA fragment containing the citP gene from Lactococcus lactis subsp. lactis biovar diacetylactis NCDO176. Cloning and nucleotide sequence analysis of Leuconostoc lactis NZ6070 citP revealed almost complete identity to lactococcal citP.

Nucleotide sequence and structural organization of the small, broad-host-range plasmid pCI411 from Leuconostoc lactis 533

The nucleotide sequence of the Leuconostoc lactis 533 cryptic plasmid pCI411 (2926 bp) was determined. Analysis revealed the presence of three open reading frames (ORFs). ORF 1 was capable of encoding a 24.9 kDa peptide which shared homology with the replication initiation protein (RepB) from a number of Gram-positive rolling circle plasmids. ORF 2 could encode a peptide of 6.6 kDa which was homologous to the RepC protein of the lactococcal plasmid pWV01. A function could not be assigned to ORF 3, which was capable of encoding a 12.1 kDa peptide. Transcription-translation analysis indicated the presence of three peptides of the predicted molecular masses. A putative double strand origin of replication (DSO) was identified which showed strong similarity with the DSO of a number of Gram-positive plasmids including pE194 from Staphylococcus. Structural analysis identified a number of direct and indirect repeats in addition to putative recombination-specific sites (RSA and RSB) in the non-coding region of pCI411. The observed characteristics suggest that this plasmid replicates using the rolling circle mechanism. pCI411, which could be introduced into Leuconostoc, Lactococcus, Streptococcus, Lactobacillus and Bacillus is the first plasmid from the genus Leuconostoc to be characterized in such detail.

A comparative study of neonates' umbilical cord management

The aim of this study was to establish the effect of treating neonates' umbilical cords with chlorhexidine 0.5% in alcohol 70% on cord separation time and to observe the clinical and microbiological consequences of not treating the cords of healthy neonates. The treated group contained 466 babies whose cords were treated with chlorhexidine, 424 babies were not treated. Microbiological colonisation patterns of the cords of babies in both groups were monitored both for purposes of this investigation and to ensure that no untoward consequences resulted from non-treatment. The research showed that treatment prolonged separation time by 1.7 days, which was significant at the level of p = 0.000, and that normal colonisation was delayed in the treated group.

A neuropsychological perspective on dual diagnosis

The purpose of this study was to investigate whether patients experiencing both a major psychiatric disorder and a concurrent substance abuse problem (dual diagnosis) manifest greater neuropsychological dysfunctions than patients experiencing a major psychiatric disorder alone. Differences in diagnostic variability and fluidity between dual diagnosis and non-dual diagnosis patients and the occurrence of polysubstance abuse among the dual diagnosis patients were also investigated. The hypotheses were tested by retrospectively reviewing the psychiatric records of 50 dual diagnosis patients and comparing them to 36 chronically hospitalized non-dual diagnosis psychiatric patients. Results revealed that dual diagnosis patients manifested significantly greater neuropsychological impairments than non-dual diagnosis patients and that dual diagnosis patients showed a greater range of diagnoses and diagnostic fluidity than non-dual diagnosis patients. Results also revealed that over one-half of the dual diagnosis patients abused a variety of different substances. An etiological role of neuropsychological dysfunction in the development of the dual diagnosis syndrome in at least a subgroup of dual diagnosis patients is suggested. More specifically, it is suggested that the neuropsychological dysfunctional pattern that is described may represent an organic substrate of a nonspecific vulnerability to developing both (atypical) psychoses and (poly) substance abuse.

Clonal origin of dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is a malignant tumor originating in the dermis. Although it is known to be locally aggressive, it only rarely metastasizes and will recur unless completely excised. The exact cell responsible for the development of a DFSP has been a matter of controversy for several decades; however, most histochemical and electron microscopic studies support a fibroblastic origin, with the tumor cells staining uniformly for vimentin and containing active endoplasmic reticulum synthesizing collagen. Cytogenetic analysis of some of these tumors has demonstrated at least two specific chromosomal abnormalities in DFSP and suggested that this tumor may be polyclonal in origin. To further address the clonal origin of this locally invasive, mesenchymal tumor, we analyzed DNA from two female patients by restriction fragment length polymorphisms and methylation analysis. Our data strongly support the concept that DFSP is monoclonal in origin and that this tumor mass reflects the clonal expansion of a single cell.

Plasmid involvement in the formation of a spontaneous bacteriophage insensitive mutant of Lactococcus lactis

Lactococcus lactis subsp. lactis biovar. diacetylactis DPC721 is a spontaneous bacteriophage insensitive mutant of strain DPC220, isolated after challenge with an industrial bacteriophage, phi D1. Plasmid analysis demonstrated that the bacteriophage insensitivity was associated with the absence of two native DPC220 plasmids (pAH82 and pAH33), and the presence of a novel plasmid (pAH90) in DPC721. The plasmids were transferred by conjugative mobilization to a plasmid free background where it was confirmed by restriction mapping that pAH90 is a co-integrate formed by the precise recombination of pAH82 and pAH33. The resistance phenotype encoded by pAH90 was also active against two bacteriophage homologous for the plasmid-free strain. Plasmid pAH90 was shown to encode at least two independent resistance mechanisms, including an adsorption-inhibition mechanism and a restriction and modification system. The adsorption-inhibition mechanism encoded by the co-integrate plasmid was specific for one of the phage used in this study.