Clinical relevance of partial HPV16/18 genotyping in stratifying HPV-positive women attending routine cervical cancer screening: a population-based cohort study

Objective

To evaluate partial HPV16/18 genotyping as a possible biomarker to select women attending HPV‐based cervical cancer screening at higher risk to be referred to colposcopy.

Design

Population‐based cohort study.

Setting

Organised cervical cancer screening programmes (Italy).

Population

Women with high‐risk HPV infection (period: 2015–2019).

Methods

We analysed the association between partial HPV16/18 genotyping, cytology triage and histologically confirmed diagnosis of high‐grade cervical intraepithelial neoplasia (CIN3⁺) lesions.

Main outcome measures

Detection rate (DR) and positive predictive value (PPV) for histologically confirmed CIN3⁺ (any episode in the 2 years after baseline); sensitivity for CIN3⁺ and number of colposcopies needed for lesion detection.

Results

The study included 145 437 women screened with HPV testing by the clinically validated COBAS 4800 HPV assay (Roche). Overall, 9601 (6.6%) women were HPV⁺ at baseline; HPV16 and HPV18 were present in 1865 and 594 samples, respectively. The cumulative (baseline plus 1‐year repeat) cytology positivity was 42.8% and high‐grade cytology was significantly higher (P < 0.0001) among women with HPV16 infection at baseline (15.2%). The cumulative CIN3⁺ DR for women with HPV16, HPV18 and other HPV‐type infections was 9.8%, 3.4% and 1.8%, respectively.

Conclusions

Partial HPV16 genotyping may play a role in triage, whereas HPV18 seems to behave much more similarly to the other HPV types and does not provide additional stratification. HPV16 genotyping combined with high‐grade cytology can be envisaged as a triage biomarker in cervical screening to maximise CIN3⁺ detection while minimising colposcopy at baseline or 1‐year repeat.

Tweetable abstract

HPV16 genotyping combined with high‐grade cytology can be used as triage biomarker for CIN3⁺ in HPV‐positive women.

HPV16 genotyping combined with high‐grade cytology can be used as a triage biomarker for CIN3⁺ in HPV‐positive women.

The charm of structural neuroimaging in insanity evaluations: guidelines to avoid misinterpretation of the findings

Despite the popularity of structural neuroimaging techniques in twenty-first-century research, its results have had limited translational impact in real-world settings, where inferences need to be made at the individual level. Structural neuroimaging methods are now introduced frequently to aid in assessing defendants for insanity in criminal forensic evaluations, with the aim of providing "convergence" of evidence on the mens rea of the defendant. This approach may provide pivotal support for judges' decisions. Although neuroimaging aims to reduce uncertainty and controversies in legal settings and to increase the objectivity of criminal rulings, the application of structural neuroimaging in forensic settings is hampered by cognitive biases in the evaluation of evidence that lead to misinterpretation of the imaging results. It is thus increasingly important to have clear guidelines on the correct ways to apply and interpret neuroimaging evidence. In the current paper, we review the literature concerning structural neuroimaging in court settings with the aim of identifying rules for its correct application and interpretation. These rules, which aim to decrease the risk of biases, focus on the importance of (i) descriptive diagnoses, (ii) anatomo-clinical correlation, (iii) brain plasticity and (iv) avoiding logical fallacies, such as reverse inference. In addition, through the analysis of real forensic cases, we describe errors frequently observed due to incorrect interpretations of imaging. Clear guidelines for both the correct circumstances for introducing neuroimaging and its eventual interpretation are defined.

Performance of ultra-low-dose CT for the evaluation of coronary calcification: a direct comparison with coronary calcium score

AIM

To evaluate the diagnostic performance of ultra-low-dose computed tomography (ULDCT) in comparison to standard coronary calcium score (CCS) acquisition for the evaluation of coronary artery calcification (CAC).

MATERIALS AND METHODS

Standard CCS acquisition and ULDCT were performed in patients referred for coronary CT angiography for the evaluation of coronary artery disease. CAC in ULDCT was graded subjectively using a four-point scale (from 0, no calcification, to 3, severe calcification) for the complete study and for each individual coronary segment. The summation of all individual coronary segment scores generated an ULDCT total CAC score. ULDCT results were compared to standard Agatston score and sensitivity and specificity of ULDCT were calculated.

RESULTS

CCS and ULDCT were performed in 74 patients, with a mean DLP of 77.7 mGy·cm (±12.1) and 9.3 mGy·cm (±0.6), respectively (p<0.001). Coronary calcification was detected in 47 patients (63.5%) in standard CCS acquisition (median Agatston score of 41; interquartile range [IQR]:0263), in comparison to 42 patients (56.8%) in ULDCT (p<0.001). The sensitivity and specificity of the ULDCT total CAC score ≥1 was 80.9% and 85.2%, respectively, with an accuracy of 82.4%. The area under the receiver operating characteristic curve for the presence of CAC was 0.87.

CONCLUSION

ULDCT shows good sensitivity, specificity, and overall accuracy for the detection of coronary calcification with a markedly lower radiation dose in comparison to CCS. ULDCT is unlikely to miss coronary calcification in individuals with at least moderate calcium load (Agatston score >100).

A correlational study between signature, writing abilities and decision-making capacity among people with initial cognitive impairment

BACKGROUND

Some clinical conditions, including dementia, compromise cognitive functions involved in decision-making processes, with repercussions on the ability to subscribe a will. Because of the increasing number of aged people with cognitive impairment there is an acute and growing need for decision-making capacity evidence-based assessment.

AIMS

Our study investigates the relationship between writing abilities and cognitive integrity to see if it is possible to make inferences on decision-making capacity through handwriting analysis. We also investigated the relationship between signature ability and cognitive integrity.

METHODS

Thirty-six participants with diagnosis of MCI and 38 participants with diagnosis of initial dementia were recruited. For each subject we collected two samples of signature-an actual and a previous one-and an extract of spontaneous writing. Furthermore, we administered a neuropsychological battery to investigate cognitive functions involved in decision-making.

RESULTS

We found significant correlations between spontaneous writing indexes and neuropsychological test results. Nonetheless, the index of signature deterioration does not correlate with the level of cognitive decline.

DISCUSSION

Our results suggest that a careful analysis of spontaneous writing can be useful to make inferences on decision-making capacity, whereas great caution should be taken in attributing validity to handwritten signature of subjects with MCI or dementia.

CONCLUSIONS

The analysis of spontaneous writing can be a reliable aid in cases of retrospective evaluation of cognitive integrity. On the other side, the ability to sign is not an index of cognitive integrity.

Large cell carcinoma of the lung: clinically oriented classification integrating immunohistochemistry and molecular biology

This study aimed at challenging pulmonary large cell carcinoma (LLC) as tumor entity and defining different subgroups according to immunohistochemical and molecular features. Expression of markers specific for glandular (TTF-1, napsin A, cytokeratin 7), squamous cell (p40, p63, cytokeratins 5/6, desmocollin-3), and neuroendocrine (chromogranin, synaptophysin, CD56) differentiation was studied in 121 LCC across their entire histological spectrum also using direct sequencing for epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations and FISH analysis for ALK gene translocation. Survival was not investigated. All 47 large cell neuroendocrine carcinomas demonstrated a true neuroendocrine cell lineage, whereas all 24 basaloid and both 2 lymphoepithelioma-like carcinomas showed squamous cell markers. Eighteen out of 22 clear cell carcinomas had glandular differentiation, with KRAS mutations being present in 39 % of cases, whereas squamous cell differentiation was present in four cases. Eighteen out of 20 large cell carcinomas, not otherwise specified, had glandular differentiation upon immunohistochemistry, with an exon 21 L858R EGFR mutation in one (5 %) tumor, an exon 2 KRAS mutation in eight (40 %) tumors, and an ALK translocation in one (5 %) tumor, whereas two tumors positive for CK7 and CK5/6 and negative for all other markers were considered adenocarcinoma. All six LCC of rhabdoid type expressed TTF-1 and/or CK7, three of which also harbored KRAS mutations. When positive and negative immunohistochemical staining for these markers was combined, three subsets of LCC emerged exhibiting glandular, squamous, and neuroendocrine differentiation. Molecular alterations were restricted to tumors classified as adenocarcinoma. Stratifying LCC into specific categories using immunohistochemistry and molecular analysis may significantly impact on the choice of therapy.

When the single matters more than the group: very high false positive rates in single case Voxel Based Morphometry

Voxel Based Morphometry (VBM) studies typically involve a comparison between groups of individuals; this approach however does not allow inferences to be made at the level of the individual. In recent years, an increasing number of research groups have attempted to overcome this issue by performing single case studies, which involve the comparison between a single subject and a control group. However, the interpretation of the results is problematic; for instance, any significant difference might be driven by individual variability in neuroanatomy rather than the neuropathology of the disease under investigation, or might represent a false positive due to the data being sampled from non-normally distributed populations. The aim of the present investigation was to empirically estimate the likelihood of detecting significant differences in gray matter volume in individuals free from neurological or psychiatric diagnosis. We compared a total of 200 single subjects against a group of 16 controls matched for age and gender, using two independent datasets from the Neuroimaging Informatics Tools and Resources Clearinghouse. We report that the chance of detecting a significant difference in a disease-free individual is much higher than previously expected; for instance, using a standard voxel-wise threshold of p<0.05 (corrected) and an extent threshold of 10 voxels, the likelihood of a single subject showing at least one significant difference is as high as 93.5% for increases and 71% for decreases. We also report that the chance of detecting significant differences was greatest in frontal and temporal cortices and lowest in subcortical regions. The chance of detecting significant differences was inversely related to the degree of smoothing applied to the data, and was higher for unmodulated than modulated data. These results were replicated in the two independent datasets. By providing an empirical estimation of the number of significant increases and decreases to be expected in each cortical and subcortical region in disease-free individuals, the present investigation could inform the interpretation of future single case VBM studies.

Activating c-KIT mutations in a subset of thymic carcinoma and response to different c-KIT inhibitors

BACKGROUND

To analyze a multi-institutional series of type C thymic carcinomas (TCs) (including neuroendocrine tumors), focusing on the expression and mutations of c-KIT.

MATERIALS AND METHODS

Immunohistochemical expression of c-KIT/CD117, p63, CD5 and neuroendocrine markers, as well as mutational analysis of c-KIT exons 9, 11, 13, 14, 17 by direct sequencing of 48 cases of TCs. Immunohistochemical and molecular data were statistically crossed with clinicopathological features.

RESULTS

Overall, 29 tumors (60%) expressed CD117, 69% were positive for CD5 and 85% (41 cases) for p63. Neuroendocrine markers stained all six atypical carcinoids and five poorly-differentiated thymic squamous cell carcinomas. Overall, six CD117-positive cases (12.5%) showed c-KIT mutation. No mutation was detected in CD117-negative tumors and carcinoids. All the mutations were found in poorly-differentiated thymic squamous cell carcinomas expressing CD117, CD5, p63 and lacking neuroendocrine markers (6 of 12 cases with these features). Mutations involved exon 11 (four cases: V559A, L576P, Y553N, W557R), exon 9 (E490K) and exon 17 (D820E).

CONCLUSIONS

All TCs need an immunohistochemical screening with CD117, while c-KIT mutation analysis is mandatory only in CD117-positive cases, particularly when coexpressing CD5 and p63, lacking neuroendocrine differentiation. The finding of c-KIT mutation can predict efficacy with different c-KIT inhibitors.

Prognostic role of EGFR gene copy number and KRAS mutation in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy

Background:

Epidermal growth factor receptor (EGFR), evaluated by immunohistochemistry, has been shown to have prognostic significance in patients with colorectal cancer. Gene copy number (GCN) of EGFR and KRAS status predict response and outcome in patients treated with anti-EGFR therapy, but their prognostic significance in colorectal cancer patients is still unclear.

Methods:

We have retrospectively reviewed the baseline EGFR GCN, KRAS status and clinical outcome of 146 locally advanced rectal cancer (LARC) patients treated with preoperative chemoradiotherapy. Pathological response evaluated by Dworak's tumour regression grade (TRG), disease-free survival (DFS) and overall survival (OS) were analysed.

Results:

Tumour regression grade 4 and TRG3–4 were achieved in 14.4 and 30.8% of the patients respectively. Twenty-nine (19.9%) and 33 patients (19.2%) had an EGFR/nuclei ratio >2.9 and CEP7 polisomy >50% respectively; 28 patients (19.2%) had a KRAS mutation. Neither EGFR GCN nor KRAS status was statistically correlated to TRG. 5-year DFS and OS were 63.3 and 71.5%, respectively, and no significant relation with EGFR GCN or KRAS status was found.

Conclusion:

Our data show that EGFR GCN and KRAS status are not prognostic factors in LARC treated with preoperative chemoradiation.

Giant genital cavernous haemangioma: case description and surgical management

Giant genital haemangiomas are rare occurrences. Once properly diagnosed, they should be managed by surgery with wide and deep margins. We present a clinical case and provide suggestions for diagnosis and treatment of this unusual pathology.

Rapidly-growing hemangioma of the testicle clinically simulating an aggressive neoplasm. A case report

We present a case of intraparenchymatous capillary-type hemangioma of the testicle in an adult. The patient was a 37-year-old man who showed a rapidly enlarging and palpable mass in left testicle. Radical orchiectomy was performed, and histological examination revealed an unencapsulated lobulated tumour with wide hemorrhagic portions. To our knowledge, the occurrence of rapid enlargement in a testicular hemangioma has not been previously reported, which might be explained by the development of intra-tumoural haemorrhage.

EGFR gene copy number, KRAS and BRAF status, PTEN and AKT expression analysis in patients with metastatic colon cancer treated with anti-EGFR monoclonal antibodies ± chemotherapy

e15055

Background: Cetuximab and panitumumab have proven to be effective in metastatic colon cancer (mCRC). KRAS mutation has been demonstrated to be a biomarker of resistance to both monoclonal antibodies. However the status and expression of other biomarkers of the RAS-RAF-MAPK signalling pathway can have a crucial role in sensitivity to anti-EGFR monoclonal antibodies. Methods: We have retrospectively analyzed tumor tissue biomarkers including EGFR gene copy number (GCN) by FISH, KRAS and BRAF status by PCR-based sequencing, PTEN and AKT expression by IHC in patients with mCRC treated with cetuximab and panitumumab ±chemotherapy. Response to treatment, TTP and OS were evaluated. Results: Sixty-three patients (pts) have been analyzed. Median age was 59 years (34–80); 53 pts had received cetuximab and 10 pts panitunumab. Concomitatnt chemotherapy was FOLFIRI, CPT-11, FOLFOX4 and Xeliri in 35, 13, 6 and 4 pts respectively. Five pts had received monoclonal antibodies only. Twenty- one pts were treated in 1st-2nd line and 42 pts in 3rd-4th line. So far EGFR GCN is available on 55 pts, KRAS and BRAF on 63 pts, PTEN in primary tumor (PT) on 36 pts and in metastatic (MTS) site on 24 pts, AKT on 19 pts. EGFR/nuclei ratio was > 2.9 in 31 % of the pts, KRAS and BRAF were mutated in 36.5 % and 3 % of the pts respectively; PTEN was positive in 42 % and 79 % in PT and MTS respectively. Moreover 21.8 % of the pts had EGFR/nuclei > 2.9 and CEP7 Polisomy > 50 %. Four pts achieved a partial remission (6.3 %). Partial response rate was 17 % vs. 2.6 % in pts with high and low EGFR GCN respectively (p: 0.007) and 13 % vs. 2.5 % in pts with WT and mutated KRAS respectively (p: 0.048). Median TTP was 3 months (0.83–32.9). It was 4.2 vs. 2.3 mos in pts with WT and mutated KRAS respectively (p: 0.001). Median OS was 9.7 mos (2.03–49.0) and no statistically significant differences were observed according to the biomarkers status. However a trend was observed for pts with KRAS WT 10.6 vs. 7.8 mos and for PTEN positive in PT: 9.0 vs. 5.67 mos. Conclusions: Our data confirm the predictive role of EGFR gene copy number and KRAS status on the response and survival. Complete biomarker characterization is ongoing and an analysis for interaction will be performed.

No significant financial relationships to disclose.

Expression of estrogen receptor in hemangioma of the uterine cervix: reports of three cases and review of the literature

The occurrence of hemangioma in the female genital tract, particularly in uterine cervix, is rare. The majority of them show asymptomatic behavior. Surgical excision remains curative in most of the cases. Conservative therapies such as sclerosing agents, cryotherapy, and CO(2) laser excision may be alternatively applied. We present three cases of hemangiomas of the cervix in asymptomatic women, diagnosed as cavernous hemangioma in two cases and capillary hemangioma in one. All tumors were immunoreactive for CD31, CD34, factor-VIII-related antigen. Focal expression of estrogen receptors was detected. No positivity was obtained with progesterone receptor antibodies. The presence of estrogen receptor in the endothelial cells of the hemangioma of the cervix suggests a direct role of this hormone in the hemangioma development. A possible target therapy is discussed.

Epidermal growth factor receptor gene copy number, K-ras mutation and pathological response to preoperative cetuximab, 5-FU and radiation therapy in locally advanced rectal cancer

BACKGROUND

Cetuximab improves activity of chemotherapy in metastatic colorectal cancer (mCRC). Gene copy number (GCN) of epidermal growth factor receptor (EGFR) has been suggested to be a predictive factor of response to cetuximab in patients (pts) with mCRC; on the contrary, K-ras mutation has been associated with cetuximab resistance.

PATIENTS AND METHODS

We have conducted a phase II study with cetuximab administered weekly for 3 weeks as single agent and then with 5-fluorouracil and radiation therapy as neo-adjuvant treatment for locally advanced rectal cancer (LARC). EGFR immunohistochemistry expression, EGFR GCN and K-ras mutation were evaluated on diagnostic tumor biopsy. Dworak's tumor regression grade (TRG) was evaluated on surgical specimens.

RESULTS

Forty pts have been treated; 39 pts are assessable. TRG 3 and 4 were achieved in nine (23.1%) and three pts (7.7%) respectively; TRG 3-4 rate was 55% and 5.3% in case of high and low GCN, respectively (P 0.0016). Pts with K-ras mutated tumors had lower rate of high TRG: 11% versus 36.7% (P 0.12). In pts with wild-type K-ras, TRG 3-4 rate was 58.8% versus 7.7% in case of high or low GCN, respectively (P 0.0012).

CONCLUSIONS

In pts with LARC, EGFR GCN is predictive of high TRG to cetuximab plus 5-FU radiotherapy. Moreover, our data suggest that a wild-type K-ras associated with a high EGFR GCN can predict sensitivity to cetuximab-based treatment.

Phosphorylation and activation of the atypical kinase p53-related protein kinase (PRPK) by Akt/PKB

p53-related protein kinase (PRPK), the human homologue of yeast Bud32, belonging to a small subfamily of atypical protein kinases, is inactive unless it is previously incubated with cell lysates. Here we show that such an activation of PRPK is mediated by another kinase, Akt/PKB, which phosphorylates PRPK at Ser250. We show that recombinant PRPK is phosphorylated in vitro by Akt and its phospho-form is recognized by a Ser250-phospho-specific antibody; that cell co-transfection with Akt along with wild-type PRPK, but not with its Ser250Ala mutant, results in increased PRPK phosphorylation; and that the phosphorylation of p53 at Ser15, the only known substrate of PRPK, is markedly increased by co-transfection of Akt with wild-type PRPK, but not PRPK dead mutant, and is abrogated by cell treatment with the Akt pathway inhibitor LY294002. Our data disclose an unanticipated mechanism by which PRPK can be activated and provide a functional link between this enigmatic kinase and the Akt signaling pathway.

Tumor cell proliferation and microsatellite alterations in human ameloblastoma

Ameloblastoma is the most common odontogenic tumor. It can exhibit a variety of histological patterns, a great infiltrative potential and a high recurrence rate. Mutations in microsatellite sequences are a hallmark of neoplastic transformation but little is known about their role in ameloblastoma development. In this study DNA was extracted from laser-microdissected samples of 24 ameloblastomas and was analyzed for the status of 22 microsatellite loci. The occurrence and the pattern of microsatellite alterations, in form of loss or length variation, was evaluated and correlated with the Ki67 labeling index and with other clinicopathologic parameters. The prognostic significance of these alterations was also evaluated. High Ki67 expression was significantly associated with a shorter disease-free survival (p=0.003 by log-rank test). Alterations of at least one of the selected loci was observed in all (100%) the ameloblastomas analyzed with a mean of 4 altered microsatellites for each tumor. The microsatellites most frequently altered were D9S747 and D11S488 (42%). All the other loci analyzed were altered in less than 40% of cases and some of them (D3S1312, D3S1300, IFNA, D9S164, D13S176 and TP53) did not show alterations in any of the ameloblastomas analyzed. No relationship was observed between the occurrence of microsatellite alterations and other parameters, such as patients age and gender, tumor size, localization and histotype. The occurrence of microsatellite alterations was more frequent in tumors displaying a high Ki67 labeling index (p=0.03) and in a univariate analysis was predictor of an increased risk of disease recurrence (p=0.039 by log-rank test). These findings demonstrate that microsatellite alterations are frequent event in ameloblastomas. They also suggest that evaluation of tumor cells proliferative activity and microsatellite alterations may be helpful to stratify ameloblastomas prognostically and to predict the clinical behavior of these tumors.

Lie-specific involvement of dorsolateral prefrontal cortex in deception

Lies are intentional distortions of event knowledge. No experimental data are available on manipulating lying processes. To address this issue, we stimulated the dorsolateral prefrontal cortex (DLPFC) using transcranial direct current stimulation (tDCS). Fifteen healthy volunteers were tested before and after tDCS (anodal, cathodal, and sham). Two types of truthful (truthful selected: TS; truthful unselected: TU) and deceptive (lie selected: LS; lie unselected: LU) responses were evaluated using a computer-controlled task. Reaction times (RTs) and accuracy were collected and used as dependent variables. In the baseline task, the RT was significantly longer for lie responses than for true responses ([mean +/- standard error] 1153.4 +/- 42.0 ms vs. 1039.6 +/- 36.6 ms; F(1,14) = 27.25, P = 0.00013). At baseline, RT for selected pictures was significantly shorter than RT for unselected pictures (1051.26 +/- 39.0 ms vs. 1141.76 +/- 41.1 ms; F(1,14) = 34.85, P = 0.00004). Whereas after cathodal and sham stimulation, lie responses remained unchanged (cathodal 5.26 +/- 2.7%; sham 5.66 +/- 3.6%), after anodal tDCS, RTs significantly increased but did so only for LS responses (16.86 +/- 5.0%; P = 0.002). These findings show that manipulation of brain function with DLPFC tDCS specifically influences experimental deception and that distinctive neural mechanisms underlie different types of lies.

The value of c-kit mutational analysis in a cytokeratin positive gastrointestinal stromal tumour

The expression of cytokeratins in gastrointestinal stromal tumours (GISTs) is rare and may lead to diagnostic confusion when it occurs. This report describes a metastatic GIST that stained strongly for cytokeratins, CD117, and CD34 in a patient who was previously diagnosed with gastric epithelioid angiosarcoma. A review of both tumours showed the same histological and immunohistochemical profiles, and c-kit molecular analysis revealed an insertional mutation at codon 558 of exon 11 in both tumours. Thus, pathologists should be aware that GISTs can occasionally express cytokeratins, and that c-kit mutational investigations may have a key diagnostic role and may prevent diagnostic mistakes that could have important clinical implications.

Semantic relevance best predicts normal and abnormal name retrieval

The relevance of a semantic feature measures its contribution to the "core" meaning of a concept. In a naming-to-description task, we investigated the predictive power of relevance in comparison with frequency, familiarity, typicality, and Age-of-Acquisition. In a group of Alzheimer patients with semantic disorder, relevance turned out to be the best predictor of name retrieval accuracy in a naming-to-description task. The same pattern of results was observed in normal controls. Relations between semantic relevance and the parameters of the concepts are discussed in order to highlight the mechanism of concept activation in a naming-to-description task.

Bone metastases in the hip region: surgical treatment

Subjective factors of the patient such as age, weight, occupation, expectations, etc. must be carefully evaluated in terms of surgery. It is always important to remember life expectancy, and the choice of a surgical procedure must be based on it. Limited survival and possible radiation therapy must eliminate methods that require long healing times: we no longer use bone grafts because the risk of healing time taking up too much of the time left for the patient is too high. Reconstructions must have an immediate solidity allowing early use of the limb. Thus, in the proximal femur, we above all use protheses (traditional or modular RPS); in acetabular lesions that do not involve the joint surface, our treatment of choice is curettage with liquid nitrogen and cement, armed with screws and nails. Prostheses, which are always cemented, are assembled using bipolar cups; cases where lysis is so wide on the cotyloid side as to require THR are rare. The cotyles, in cases such as these, are those that allow for anchoring with several sites (Octopus type), the McMinn or, at times, common cotyles in PE.

Resection of the proximal humerus for metastases and replacement with RPS prosthesis

In the surgical treatment of metastatic lesions of the proximal humerus it is important to find solutions that eliminate pain and solve the mechanical problem in a short time and with reduced costs. In 90% of cases, intralesional curettage, freezing with liquid nitrogen and cement enhanced intramedullary instrumentation is capable of brilliantly solving the problems of these patients. When, instead, osteolysis involves the greater tuberosity and/or the joint region, resection of the proximal humerus followed by reconstruction with a modular prosthesis is indicated. Of those available on the market, the RPS system (LIMA) has features that make it equivalent to others, but at costs considerably lower. However, in reconstructions with prostheses, active abduction is significantly limited. A personal series of 20 patients is presented.

Computationally inexpensive methods for intra-cardiac atrial bipolar electrogram compression

AIM

This paper reports studies of mathematical algorithms for intra-cardiac atrial bipolar electrogram compression suitable with implementation on implantable devices.

PATIENTS AND METHODS

Bipolar intra-cardiac electrograms (IEGMs) of high right atrium were obtained from 20 patients who underwent electrophysiological studies for arrhythmias. Four thousand seven hundred and eighty-two seconds of IEGM were collected and divided into three rhythm groups: sinus rhythm (SR), atrial fibrillation (AF) and atrial flutter (AFL). Since mathematical algorithms suitable for use with implantable devices demand low computational cost, we employed piecemeal linear approximation methods (ZOP--Zero Order Prediction and SAPA--Scan Along Polygonal Approximation), and beat detection method (Peak) both or which need small numbers of operations to perform electrogram compression. Compression ratio (CR) and percent root mean square difference (PRD) were used to compare the three methods, with statistical analyses performed using paired t-test.

RESULTS AND CONCLUSION

The best performance was obtained using the Peak method which reaches an average CR of 10.6 in the case of SR group, 2.8 for AF, and 3.6 for AFL groups, respectively, while PRD lies below 2% for SR and AFL groups and 6% for the AF group. Results show that, for bipolar electrograms, the Peak method reaches statistically significant better performance (P<0.001) in all cases except for Peak vs SAPA applied to AF (P=0.2). The number of operations necessary to compress the data indicate that time consumption can be reduced to be suitable for real time compression in implantable devices. The Peak method, which was assumed to receive the instant of occurrence of each recognized beat, from the hardware of the device, requires fewer operations than ZOP and SAPA. Increasing the length of electrograms recorded in pacemakers will enhance the amount of information provided by the implantable device, allowing more detailed characterization of the intra-cardiac activity and leading to new perspectives in arrhythmia diagnosis and therapy.