Survival in breast cancer patients with a delayed DIEP flap breast reconstruction after adjustment for socioeconomic status and comorbidity

Purpose

Overall survival in breast cancer patients receiving a delayed deep inferior epigastric perforator (DIEP) flap breast reconstruction is better than in those without delayed breast reconstruction. This study aimed at determining the impact of socioeconomic status (SES) and comorbidity on these observations.

Materials and methods

This matched cohort study included all consecutive women undergoing a delayed DIEP flap reconstruction at Karolinska University Hospital, Sweden, between 1999 and 2013. Controls had not received any delayed breast reconstruction and were relapse-free after a corresponding follow-up interval. Matching was by year of and age at mastectomy, tumour stage and lymph node status. Charlson Comorbidity Index (CCI) and socioeconomic data were obtained from national registers. Associations with breast cancer-specific (BCSS) and overall survival (OS) were investigated by Kaplan-Meier survival estimates and Cox proportional hazard regression analysis.

Results

Women in the DIEP group (N = 254) more often continued education after primary school (88.6% versus 82.6%, P = 0.026), belonged to the high-income group (76.0% versus 63.1%, P < 0.001), were in a partnership (57.1% versus 55.7%, P = 0.024) and healthier (median CCI 1.00 (range 0–13) versus 2.00 (range 0–16), P = 0.021) than the control group (N = 729). After adjustment for tumour and treatment factors, SES and comorbidity, OS remained significantly better for the DIEP group than the control group (HR 2.27, 95% CI 1.44–3.55).

Conclusion

Women with a delayed DIEP flap reconstruction are a subgroup of higher socioeconomic status and better health. Higher survival estimates for the DIEP group persisted after adjusting for those differences, suggesting the presence of further unmeasured covariates.

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Women with a delayed DIEP flap reconstruction have a higher socioeconomic status.

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They also have less comorbidity than women with no delayed reconstruction.

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Superior survival in DIEP patients is not eliminated by adjustments for such differences.

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Unmeasured selection to the reconstructive process may explain observed survival differences.

Autologous fat transplantation alters gene expression patterns related to inflammation and hypoxia in the irradiated human breast

BACKGROUND

Radiation-induced fibrosis, an adverse effect of breast cancer treatment, is associated with functional and cosmetic impairment as well as surgical complications. Clinical reports suggest improvement following autologous fat transplantation, but the mechanisms underlying this effect are unknown. A global gene expression analysis was undertaken to identify genetic pathways dysregulated by radiation and evaluate the impact of autologous fat transplantation on gene expression.

METHODS

Adipose tissue biopsies were taken synchronously from irradiated and contralateral non-irradiated breasts, before and 1 year after autologous fat transplantation. Whole-genome gene expression analyses were performed, and Hallmark gene set analysis used to explore the effect of radiotherapy and autologous fat transplantation on gene expression.

RESULTS

Forty microarrays were analysed, using bilateral biopsies taken from ten patients before and after autologous fat transplantation. Forty-five pathways were identified among the 3000 most dysregulated transcripts after radiotherapy in irradiated compared with non-irradiated breast (P ≤ 0·023; false discovery rate (FDR) no higher than 0·026). After autologous fat transplantation, 575 of the 3000 genes were again altered. Thirteen pathways (P ≤ 0·013; FDR 0·050 or less) were identified; the top two canonical pathways were interferon-γ response and hypoxia. Correlative immunohistochemistry showed increased macrophage recruitment in irradiated tissues.

CONCLUSION

The present findings contribute to understanding of how autologous fat transplantation can ameliorate radiation-induced fibrosis. This further supports the use of autologous fat transplantation in the treatment of radiation-induced fibrosis. Surgical relevance Clinical studies have indicated that autologous fat transplantation (AFT) stimulates regression of chronic inflammation and fibrosis caused by radiotherapy in skin and subcutaneous fat. However, there is a paucity of biological evidence and the underlying processes are poorly understood. Human data are scarce, whereas experimental studies have focused mainly either on the effect of irradiation or AFT alone. The present results indicate that radiotherapy causes dysregulated gene expression in fibrosis-related pathways in adipose tissues in humans. They also show that AFT can cause a reversal of this, with several dysregulated genes returning to nearly normal expression levels. The study provides biological evidence for the impact of AFT on radiation-induced dysregulated gene expression in humans. It supports the use of AFT in the treatment of radiation-induced fibrosis, associated with severe morbidity and surgical challenges.

Abstract 4405: Pharmacologic profile of INT-1B3: A novel synthetic microRNA 193a-3p mimic for therapeutic intervention in oncology

MicroRNAs (miRNAs) are a family of small, non-coding RNAs and serve as small snippets of genetic material that regulate gene expression. As a result, miRNAs modulate a wide range of biological processes including; cell cycle control and apoptosis, cell signaling and differentiation, cell adhesion and motility. Thus, it is not surprising that their misregulation is linked to cancer initiation, treatment response, and metastasis. Due to the inherent ability of miRNAs to concurrently target multiple pathways, their therapeutic potential to be used as anti-cancer drugs is attractive. In this study, we are investigating the mode of action and development of a novel synthetic miRNA mimic (INT-1B3) as a therapeutic candidate for substitution and functional restoration of a depleted miRNA in variety of cancers. To identify miRNAs that control the survival of cancer cells, we performed a functional miRNA screening in which a wide range of relevant miRNAs were selected and miR-193a-3p was chosen as the potential candidate for further preclinical characterization. Compelling evidence demonstrate a tumor suppressor function for miR-193a-3p in many cancer types and link its reduced expression with cancer, metastasis and therapy resistance. Consistent with the described role for miR-193a-3p in literature, our cell-based assays conducted in various experimental tumor cell systems demonstrated efficient target engagement leading to reduced cell proliferation/survival, cell cycle arrest and induction of apoptosis, inhibition of cell motility as well as a potential immune-modulatory role (via adenosine-mediated tumor immune evasion). Furthermore, development of a novel lipid nanoparticle-based formulation as an efficient delivery system demonstrated a marked anti-tumor activity of INT-1B3 as single agent following systemic administration in tumor-bearing mice. Robust tumor growth inhibition in these experimental tumor models is correlated and consistent with efficient target engagement in tumor cells and relevant organs. We are currently investigating the in vitro and in vivo effect of INT-1B3 in variety of cancer types including hepatocellular carcinoma, melanoma and triple negative breast cancer. Our data thus far supports an anti-tumor role for INT-1B3 and encourages further preclinical and clinical investigation.

Citation Format: Sanaz Yahyanejad, Thijs de Gunst, Iman Schultz, Harm den Boer, Monica Raimo, Bryony Telford, Rogier Vos, Laurens van Pinxteren, Roel Schaapveld, Michel Janicot. Pharmacologic profile of INT-1B3: A novel synthetic microRNA 193a-3p mimic for therapeutic intervention in oncology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4405.

Risk of recurrence and death in patients with breast cancer after delayed deep inferior epigastric perforator flap reconstruction

Background

Postmastectomy reconstruction using a deep inferior epigastric perforator (DIEP) flap is increasingly being performed in patients with breast cancer. The procedure induces extensive tissue trauma, and it has been hypothesized that the release of growth factors, angiogenic agonists and immunomodulating factors may reactivate dormant micrometastasis. The aim of the present study was to estimate the risk of breast cancer recurrence in patients undergoing DIEP flap reconstruction compared with that in patients treated with mastectomy alone.

Methods

Each patient who underwent delayed DIEP flap reconstruction at Karolinska University Hospital, Sweden, between 1999 and 2013, was compared with up to four controls with breast cancer who did not receive a DIEP flap. The control patients were selected using incidence density matching with respect to age, tumour and nodal status, neoadjuvant therapy and year of mastectomy. The primary endpoint was breast cancer‐specific survival. Survival analysis was carried out using Kaplan–Meier survival estimates and Cox proportional hazard regression analysis.

Results

The analysis included 250 patients who had 254 DIEP flap reconstructions and 729 control patients. Median follow‐up was 89 and 75 months respectively (P = 0·053). Breast cancer recurrence developed in 50 patients (19·7 per cent) in the DIEP group and 174 (23·9 per cent) in the control group (P = 0·171). The 5‐year breast cancer‐specific survival rate was 92·0 per cent for patients with a DIEP flap and 87·9 per cent in controls (P = 0·032). Corresponding values for 5‐year overall survival were 91·6 and 84·7 per cent (P < 0·001). After adjustment for tumour and patient characteristics and treatment, patients without DIEP flap reconstruction had significantly lower overall but not breast cancer‐specific survival.

Conclusion

The present findings do not support the hypothesis that patients with breast cancer undergoing DIEP flap reconstruction have a higher rate of breast cancer recurrence than those who have mastectomy alone.

Deep inferior epigastric perforator is safe

Abstract P4-13-14: Risk of recurrence and death in breast cancer patients after delayed deep inferior epigastric perforator flap reconstruction

PURPOSE

Post-mastectomy reconstruction using the deep inferior epigastric perforator (DIEP) flap is increasingly performed in breast cancer patients. The procedure induces large tissue trauma and it has been hypothesized that the release of growth factors, angiogenic agonists and immunomodulating factors may reactivate dormant micrometastasis. The aim of our study was to contrast the risk of breast cancer recurrence in patients undergoing DIEP reconstruction to patients treated with mastectomy alone.

PATIENTS AND METHODS

We conducted a retrospective nested case-control study. Cases were defined as breast cancer patients operated with delayed DIEP reconstruction at Karolinska University Hospital, Sweden, between 1999-2013. Three controls, defined as breast cancer patients operated with conventional mastectomy without delayed reconstruction, were matched to each case based on age, tumour stage and year of mastectomy. The primary endpoint was breast cancer-specific survival. Survival analysis was carried out by Kaplan–Meier survival estimates and Cox proportional hazard regression analysis.

RESULTS

In all, 254 cases and 729 controls were included and had a median follow up of 134 and 122 months, respectively (p=0.004). Breast cancer recurrence occurred in 50 (19.7%) cases and 174 (23.9%) controls, respectively (p=0.171). Ten-year breast cancer-specific survival was 90.7% for cases and 85.2% in controls (p=0.067). The corresponding figures for 10-year overall survival was 89.6% and 80.0%, respectively (p&lt;0.001). Higher tumor stage and positive axillary lymph nodes, but not DIEP reconstruction, were independent risk factors for death due to breast cancer.

CONCLUSION

Our findings did not support the hypothesis that breast cancer patients undergoing DIEP reconstruction would have a higher rate of breast cancer recurrence than patients undergoing mastectomy alone.

Citation Format: Adam H, Docherty Skogh A-C, Edsander Nord Å, Schultz I, Gahm J, Hall P, Frisell J, Halle M, de Boniface J. Risk of recurrence and death in breast cancer patients after delayed deep inferior epigastric perforator flap reconstruction [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-13-14.

miRNA-520f Reverses Epithelial-to-Mesenchymal Transition by Targeting ADAM9 and TGFBR2

Reversing epithelial-to-mesenchymal transition (EMT) in cancer cells has been widely considered as an approach to combat cancer progression and therapeutic resistance, but a limited number of broadly comprehensive investigations of miRNAs involved in this process have been conducted. In this study, we screened a library of 1120 miRNA for their ability to transcriptionally activate the E-cadherin gene CDH1 in a promoter reporter assay as a measure of EMT reversal. By this approach, we defined miR-520f as a novel EMT-reversing miRNA. miR-520f expression was sufficient to restore endogenous levels of E-cadherin in cancer cell lines exhibiting strong or intermediate mesenchymal phenotypes. In parallel, miR-520f inhibited invasive behavior in multiple cancer cell systems and reduced metastasis in an experimental mouse model of lung metastasis. Mechanistically, miR-520f inhibited tumor cell invasion by directly targeting ADAM9, the TGFβ receptor TGFBR2 and the EMT inducers ZEB1, ZEB2, and the snail transcriptional repressor SNAI2, each crucial factors in mediating EMT. Collectively, our results show that miR-520f exerts anti-invasive and antimetastatic effects in vitro and in vivo, warranting further study in clinical settings. Cancer Res; 77(8); 2008-17. ©2017 AACR.

Abstract 1112: Identification of microRNA-based therapeutic candidates using a unique lentiviral microRNA overexpression library

microRNA (miRNA) genes transcribed by RNA polymerase II generate small noncoding miRNAs of 18 to 24 nucleotides after maturation process. The mature miRNAs and their associated isomirs specifically bind to different mRNA transcripts, resulting in down regulation of multiple genes within the cell in a highly multiplexed way. miRNA expression profiles differ between human cell types suggesting cell-specific impacts of each miRNA on the regulation of different biological processes. Comparison of miRNA profiles of tumor samples and adjacent normal tissues showed that some miRNAs are up- or down- regulated and suggested their implication during tumor progression. However, such a miRNA profiling approach is not sufficient to identify the respective role of each miRNA gene during the tumorigenesis. Here, to assess the individual role of each miRNA gene and its different isomirs in a specific cell environment, we have constructed a lentiviral miRNA expression library containing more than 1100 human known and novel miRNA precursors. The arrayed layout of our library allowed high-throughput screens with a large spectrum of functional read-outs using either normal or tumor cells. To exemplify this approach, the results of three different screens will be presented; i.e. identification of miRNAs that inhibit the BRAF pathway, miRNAs that inhibit tumor angiogenesis and miRNAs that stimulate the mesenchymal to epithelial transition. In addition, beyond this hit identification step, we will present detailed characterization of the role of the identified miRNAs in tumor progression by means of molecular and cellular functional assays. Combining our unique miRNA expression library with a functional screening platform has allowed the identification and the further characterization of several miRNAs able to significantly impact on tumor behavior supporting the therapeutic interest of some candidates.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1112. doi:1538-7445.AM2012-1112

Abstract A12: Identification of microRNA-based therapeutic candidates using a unique lentiviral microRNA overexpression library

microRNA (miRNA) genes transcribed by RNA polymerase II generate small noncoding miRNAs of 18 to 24 nucleotides after maturation process. The mature miRNAs and their associated isomirs specifically bind to different mRNA transcripts, resulting in down regulation of multiple genes within the cell in a highly multiplexed way. miRNA expression profiles differ between human cell types suggesting cell-specific impacts of each miRNA on the regulation of different biological processes. Comparison of miRNA profiles of tumor samples and adjacent normal tissues showed that some miRNAs are up- or down- regulated and suggested their implication during tumor progression. However, such a miRNA profiling approach is not sufficient to identify the respective role of each miRNA gene during the tumorigenesis.

Here, to assess the individual role of each miRNA gene and its different isomirs in a specific cell environment, we have constructed a lentiviral miRNA expression library containing more than 1100 human known and novel miRNA precursors. The arrayed layout of our library allowed high-throughput screens with a large spectrum of functional read-outs using either normal or tumor cells. To exemplify this approach, the results of three different screens will be presented; i.e. identification of miRNAs that inhibit the BRAF pathway, miRNAs that inhibit tumor angiogenesis and miRNAs that stimulate the mesenchymal to epithelial transition. In addition, beyond this hit identification step, we will present detailed characterization of the role of the identified miRNAs in tumor progression by means of molecular and cellular functional assays.

Combining our unique miRNA expression library with a functional screening platform has allowed the identification and the further characterization of several miRNAs able to significantly impact on tumor behavior supporting the therapeutic interest of some candidates.

Citation Format: Paula I. van Noort, Negar Babae, Gerald W. Verhaegh, Willemijn M. Gommans, Francesco Cerisoli, Mark Verheul, Raymond M. Schiffelers, Arjan W. Griffioen, Jack A. Schalken, Eugene Berezikov, Edwin Cuppen, Roel Q. J. Schaapveld, Jos B. Poell, Gregoire P. Prevost, Meriem Bourajjaj, Suzanna Vidic, Judy R. van Beijnum, Rick J. van Haastert, Iman Schultz, Thijs de Gunt, Onno van Hooij. Identification of microRNA-based therapeutic candidates using a unique lentiviral microRNA overexpression library [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer; 2012 Jan 8-11; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(2 Suppl):Abstract nr A12.

Head and neck squamous cell carcinoma transcriptome analysis by comprehensive validated differential display

Head and neck squamous cell carcinoma (HNSCC) is common worldwide and is associated with a poor rate of survival. Identification of new markers and therapeutic targets, and understanding the complex transformation process, will require a comprehensive description of genome expression, that can only be achieved by combining different methodologies. We report here the HNSCC transcriptome that was determined by exhaustive differential display (DD) analysis coupled with validation by different methods on the same patient samples. The resulting 820 nonredundant sequences were analysed by high throughput bioinformatics analysis. Human proteins were identified for 73% (596) of the DD sequences. A large proportion (>50%) of the remaining unassigned sequences match ESTs (expressed sequence tags) from human tumours. For the functionally annotated proteins, there is significant enrichment for relevant biological processes, including cell motility, protein biosynthesis, stress and immune responses, cell death, cell cycle, cell proliferation and/or maintenance and transport. Three of the novel proteins (TMEM16A, PHLDB2 and ARHGAP21) were analysed further to show that they have the potential to be developed as therapeutic targets.

Pelvic organ prolapse and urinary incontinence in women with surgically managed rectal prolapse: a population-based case-control study

PURPOSE

This study aimed to investigate the prevalence of genital prolapse surgery and urinary incontinence in female patients operated on for rectal prolapse compared with a matched control group without rectal prolapse.

METHODS

Fifty-two patients with a history of abdominal rectal prolapse surgery and 200 randomly selected age-matched and gender-matched control subjects without rectal prolapse received an extensive health care history survey.

RESULTS

Response rate in the patient group was 48 of 52 (92 percent) and 165 of 200 (82 percent) in the control group. Rectal prolapse was associated with an increased risk of surgery for uterine prolapse (odds ratio = 3.1; 95 percent confidence interval = 1.4-6.9) and vaginal wall prolapse (odds ratio = 3.2; 95 percent confidence interval = 1.3-7.8). Mean age at hysterectomy because of uterine prolapse was 54.7 years in the patient group compared with 62.6 years in the control group (P < 0.01). Mean age at vaginal wall prolapse surgery was 60.2 years in the patient group compared with 66.6 years in the control group (P < 0.05). There were no significant differences between the cohorts regarding prevalence or age at debut of urinary incontinence.

CONCLUSION

Our results indicate a strong association between rectal and genital prolapse surgery suggesting that diagnosis of rectal prolapse necessitating surgical intervention should prompt a multidisciplinary pelvic floor assessment.

Differential expression profiling of head and neck squamous cell carcinoma (HNSCC)

Head and neck squamous cell carcinoma (HNSCC) is the fifth most common cancer in men with an incidence of about 780 000 new cases per year worldwide and a poor rate of survival. There is a need for a better understanding of HNSCC, for the development of rational targeted interventions and to define new prognostic or diagnostic markers. To address these needs, we performed a large-scale differential display comparison of hypopharyngeal HNSCCs against histologically normal tissue from the same patients. We have identified 70 genes that exhibit a striking difference in expression between tumours and normal tissues. There is only a limited overlap with other HNSCC gene expression studies that have used other techniques and more heterogeneous tumour samples. Our results provide new insights into the understanding of HNSCC. At the genome level, a series of differentially expressed genes cluster at 12p12–13 and 1q21, two hotspots of genome disruption. The known genes share functional relationships in keratinocyte differentiation, angiogenesis, immunology, detoxification, and cell surface receptors. Of particular interest are the 13 ‘unknown’ genes that exist only in EST, theoretical cDNA and protein databases, or as chromosomal locations. The differentially expressed genes that we have identified are potential new markers and therapeutic targets.

Assessing pain behaviour of low-back pain patients in real time: concurrent validity and examiner sensitivity

Several systems for measuring pain behaviour have been developed for clinical settings. The present study reports on a real-time system for coding five categories of pain behaviour for low-back pain patients: guarding, touching, sounds, words, and facial expression. Unique features of the system are the use of refined measures of facial expression and integration of the measurements with a standardized physical examination. 176 sub-acute and chronic low-back pain patients underwent a physical examination while their pain behaviour was coded. Concurrent measures of subjective pain, medically-incongruent signs, and independent global ratings of pain behaviour were taken. Analyses indicated that the pain behaviours, particularly guarding and facial expression, varied systematically with the alternative measures, supporting the concurrent validity of the behaviour observation system. While pain behaviours, especially use of words and facial expressions, were significantly associated with the examiners' independent ratings, the strength of the associations suggested that, in the absence of direct training, examiners' performance was relatively poor. Implications for training of clinicians in detecting pain behaviour are discussed.

Loss of MDM2 expression in human head and neck squamous cell carcinomas and clinical significance

The transforming potential of the MDM2 oncogene has been attributed to the overproduction of the protein. In order to investigate regulation of MDM2 expression in head and neck squamous cell carcinomas, we analysed MDM2 gene amplification, and mRNA and protein expression in tumour specimens from 62 patients, in cell lines, and in normal epithelium adjacent to tumours or obtained from healthy patients. Additionally, TP53-induced MDM2-P2 transcription was evaluated and compared with TP53 status. MDM2 gene amplification and mRNA over-expression is infrequent, 7 and 9%, respectively. The predominant transcript codes for full-length MDM2 protein (90kD) and the level of alternatively spliced forms is not significant. We show that only 47% of tumours exhibit MDM2 immunostaining in more than one third of the neoplastic cells, and thus more than half of the tumours display no or low levels of MDM2 protein. In contrast, MDM2 protein is always detectable in basal and parabasal cells of morphologically normal epithelium outside the invasively growing tumour, as well as in a normal uvula sample. Similarly, the total amount of MDM2 transcripts analysed by reverse transcriptase-polymerase chain reaction is reduced in tumour samples compared to normal tissues, essentially due to a decrease in P2 transcript levels. The relationship between mutated p53 status and low levels of MDM2 found in cell lines is also observed to a certain extent in primary tumour samples. Overall, there is a high frequency of TP53 mutation and under-expression of MDM2 in the head and neck tumours. Moreover, a significant association of decreased MDM2 expression is observed with advanced tumour stage and 3 years survival.

Long-term results and functional outcome after Ripstein rectopexy

PURPOSE

The aim of this study was to evaluate operative mortality, morbidity, and functional results after Ripstein rectopexy for rectal prolapse and internal rectal intussusception.

METHODS

Sixty-nine patients with rectal prolapse and 43 with internal rectal intussusception were included. All patient records were studied and complications registered. Long-term follow-up was possible in 105 patients and performed by clinical examination and standardized interview, telephone interview, or patient records. Seventy-six patients were prospectively evaluated, comparing bowel function before and after rectopexy.

RESULTS

There was no operative mortality. Operative morbidity was 33 percent, and most complications were minor. Severe early complications included one large-bowel obstruction and one transient ureteric stenosis. Median time of follow-up was seven years in patients with rectal prolapse and 5.4 years in patients with internal rectal intussusception. Late complications included two rectovaginal fistulas and one lethal sigmoid fecaloma. Five patients underwent subtotal colectomy for severe constipation. There was one recurrent prolapse (1.6 percent). Functional evaluation showed that incontinence improved (P = 0.049), whereas the number of bowel movements per week decreased (P < 0.001). Frequency of emptying difficulties did not change significantly in patients with rectal prolapse but increased in patients with internal rectal intussusception (P = 0.038).

CONCLUSION

Ripstein rectopexy can be performed with low mortality and recurrence rate, but with a high early complication rate. There were also some serious late complications. Continence was improved, although increased constipation was a problem in some patients, especially among those with internal rectal intussusception.

Variability in the ratio of mutant to wildtype myosin heavy chain present in the soleus muscle of patients with familial hypertrophic cardiomyopathy. A new approach for the quantification of mutant to wildtype protein

The ratio of mutant to wildtype myosin heavy chain (beta-isoform, beta-MHC) in the soleus muscle of patients with familial hypertrophic cardiomyopathy was determined by a combination of HPLC, mass spectrometry and capillary zone electrophoresis. In two patients, one with a Val 606 Met mutation and another with a Gly 584 Arg mutation, the fraction of mutant beta-MHC was only 12+/-6% and 23+/-0.7% of total beta-MHC, respectively. These results demonstrate the necessity to determine the ratio of mutant to wildtype protein for the interpretation of functional studies on biopsy material from heterozygous patients with an inherited disease.

Dichloroacetate (DCA) dosimetry: interpreting DCA-induced liver cancer dose response and the potential for DCA to contribute to trichloroethylene-induced liver cancer

Pharmacokinetic studies with dichloroacetate (DCA) provide insights into the likelihood that trichloroethylene-induced liver cancers arise from formation of DCA as a metabolite and the mode of action by which DCA induces liver cancer. A simple physiologically based pharmacokinetic model was developed to analyze DCA blood concentration data from mice unexposed to or pre-treated with DCA. The large first pass metabolism of DCA in the liver is significantly reduced by DCA pretreatment. Because DCA inhibits its own metabolism, large increases in area under the blood concentration curve occur at lower doses than would be predicted from single-dose pharmacokinetic studies with naive mice. The dose metrics associated with the incidence of liver tumors in contrast to the multiplicity of tumors per animal may be different, suggesting potentially different roles in the cancer process for DCA versus its metabolites. By linking a model for trichloroethylene (TCE) pharmacokinetics with the DCA model, maximum levels of DCA potentially produced from TCE were estimated to be at or below the analytical chemistry detection limits. In addition, the predicted levels of DCA would be too small to produce the observed liver cancers following corn oil gavage exposure of mice to TCE.

Whole gut transit is prolonged after Ripstein rectopexy

OBJECTIVE

To find out if there are changes in transit time after Ripstein rectopexy and whether measurement of whole gut transit time preoperatively can predict postoperative constipation.

DESIGN

Prospective open study.

SETTING

Teaching hospital, Sweden.

SUBJECTS

30 patients undergoing Ripstein rectopexy for rectal prolapse (n = 17) or internal rectal intussusception (n = 13).

METHODS

Whole-gut transit studies and recording of symptoms of constipation preoperatively and postoperatively.

MAIN OUTCOME MEASURES

Constipation and retention of markers.

RESULTS

Significantly more markers were retained in postoperative compared with preoperative transit studies (p < 0.001). Constipation mainly presented as emptying difficulties and there was no increase in the total number of patients who reported emptying difficulties postoperatively. There was a weak but significant correlation between retention of markers preoperatively and postoperative emptying difficulties (p < 0.05).

CONCLUSION

Whole gut transit was prolonged after Ripstein rectopexy. Preoperative retention of markers indicated an increased risk of postoperative constipation.

Preoperative electrophysiologic assessment cannot predict continence after rectopexy

PURPOSE

The aim of this study was to evaluate preoperative electrophysiologic assessment for prediction of anal continence after rectopexy.

METHODS

Forty-three patients with rectal prolapse (n = 26) or internal rectal intussusception (n = 17) underwent concentric-needle electromyography, fiber density determination by single-fiber electromyography of the external anal sphincter, and pudendal nerve terminal motor latency evaluation before Ripstein rectopexy. A detailed history was obtained from each patient preoperatively and postoperatively.

RESULTS

Anal continence was improved after rectopexy, both in patients with rectal prolapse (P = 0.06) and in those with internal rectal intussusception (P = 0.003). Abnormal results were registered in one or several aspects of the electrophysiologic assessment in 31 (72 percent) of the patients. However, functional outcome with respect to continence was not predicted by preoperative electromyography or pudendal nerve terminal motor latency assessment results.

CONCLUSION

Electrophysiologic examinations in the preoperative assessment of patients with rectal prolapse and internal rectal intussusception do not predict continence after the Ripstein rectopexy. The routine use of electrophysiologic assessment requires further definition.

Paradoxical sphincter reaction is influenced by rectal filling volume

PURPOSE

Paradoxical sphincter reaction is frequently found in constipated patients but sometimes also in incontinent patients and in asymptomatic subjects. Its significance in defecation disorders has, therefore, been debated. The aim of the present study was to investigate whether paradoxical sphincter reaction is influenced by rectal filling volume.

PATIENTS AND METHODS

Eighteen patients with defecation disorders and paradoxical sphincter reaction shown by electromyography were reinvestigated with an extended electromyographic investigation while in the lying position and while in the sitting position, with 50-ml, 100-ml, and 150-ml water-filled rectal balloons.

RESULTS

All 18 patients showing paradoxical sphincter reaction in the first investigation also showed the reaction at the second investigation in the lying position with a 0-ml volume of rectal contents. In the sitting position, with a volume of 150 ml of rectal contents, the increase in electromyographic activity disappeared in seven patients (39 percent) and no longer showed paradoxical sphincter reaction. Electromyography showed decreased activity in one patient and unchanged activity in six patients during straining. A closing reflex was seen after completed straining in all of these seven patients.

CONCLUSIONS

The present study demonstrates that paradoxical sphincter reaction diagnosed by electromyography is influenced by the rectal filling volume and might diminish when the rectum is filled with contents. The conventional electrophysiologic technique in the diagnosis of paradoxical sphincter reaction might, therefore, overdiagnose this condition.

Rectocele is associated with paradoxical anal sphincter reaction

Rectocele is a frequent finding in constipated patients. However, constipation is not always relieved by rectocele repair, which may be due to other overlooked reasons for constipation. The study was designed to investigate patients with rectocele, in order to elucidate concomitant colorectal disorders and their association with rectocele. One hundred and twelve female patients suffering from severe constipation and rectal emptying difficulties were investigated using defecography, electrophysiology, anorectal manometry and colon transit time. Fifty-six patients with rectocele demonstrated by defecography were compared with 56 patients without rectocele, but with other abnormal findings at defecography. The frequency of paradoxical anal sphincter reaction (PSR) was higher in patients with rectocele (60%) than in patients without rectocele (24%). The present study supports an association between rectocele and PSR. We suggest that constipated patients with a rectocele should be investigated thoroughly before rectocele repair is considered. Further studies on the effect of biofeedback training in patients with rectocele and PSR are indicated.

Internal rectal intussusception seldom develops into total rectal prolapse

PURPOSE

This study was designed to analyze how often internal rectal intussusception develops into total rectal prolapse.

METHODS

Repeated investigations with defecography were performed in 312 patients because of persisting symptoms. In 79 patients who had a rectal intussusception at the first defecography, results of the second defecography and the patients' records were studied.

RESULTS

A total of 38 patients had not undergone any surgical treatment of rectal intussusception or rectal prolapse between the first and second defecographies. One of these patients had a rectal prolapse at the second defecography, and another developed a clinical prolapse after the second defecography.

CONCLUSIONS

The present study demonstrates that the risk of developing a rectal prolapse in patients with rectal intussusception is small. This risk should, therefore, not be used as an indication for surgery.

Delayed shoulder exercises in reducing seroma frequency after modified radical mastectomy: a prospective randomized study

BACKGROUND

Seromas and impaired shoulder function are well-known complications after modified radical mastectomy for breast cancer. Early postoperative physiotherapy is a common treatment to avoid shoulder dysfunction. The aim of this study was to evaluate if the frequency of postoperative seromas could be reduced, without increasing shoulder dysfunction, by delayed postoperative shoulder exercises.

METHODS

In a prospective study 163 patients with breast cancer undergoing modified radical mastectomy were randomized to physiotherapy starting on postoperative day 1 or day 7. Patients were seen by the surgeons and the physiotherapists during hospital stay and in the outpatient department. Seromas and other complications were registered by the surgeons. The physiotherapists instructed the patients pre- and postoperatively and assessed shoulder function.

RESULTS

There was a significantly higher incidence of postoperative seromas in the group of patients that started physiotherapy postoperative day 1 (38%) compared to the group that started physiotherapy postoperative day 7 (22%) (p < 0.05). There was no significant difference between the groups in the late outcome of shoulder function.

CONCLUSION

The incidence of seromas after modified radical mastectomy for breast cancer is reduced by delaying shoulder exercises one week postoperatively. Earlier postoperative physiotherapy is not necessary to avoid impaired shoulder function.

Breast cancer in women over 75 years: is axillary dissection always necessary?

OBJECTIVE

To study how the information gained from axillary dissection in women (75 years old or more) with breast cancer influenced postoperative adjuvant treatment.

DESIGN

Retrospective review of casenotes.

SETTING

University departments of surgery and oncology, Sweden.

SUBJECTS

166 women (aged 75 years or more) operated on for primary breast cancer between 1980-1989.

MAIN OUTCOME MEASURES

Type of operation and postoperative therapy given.

RESULTS

In 138/166 (83%) women axillary dissection was done, but in only 21/59 (36%) of these patients did information gained from the procedure influence the postoperative treatment according to the treatment guidelines for breast cancer. None of the 28 patients who did not undergo axillary dissection were subjected to further operations or radiotherapy for axillary nodal recurrence after a mean follow up of 47 months.

CONCLUSIONS

Axillary dissection should be reserved for local control of disease and for those patients who preoperatively agree to undergo postoperative irradiation or chemotherapy if metastases are found.

Continence is improved after the Ripstein rectopexy. Different mechanizms in rectal prolapse and rectal intussusception?

PURPOSE

This study was undertaken to evaluate anal manometric changes after Ripstein's operation for rectal prolapse and rectal intussusception and to study the clinical outcome following the operation, with special reference to anal incontinence.

METHODS

Forty-two patients with rectal prolapse or rectal intussusception were subjected to anorectal manometry preoperatively and seven days and six months postoperatively. A detailed history was obtained from each patient preoperatively and six months postoperatively.

RESULTS

Preoperatively, patients with rectal intussusception had higher maximum resting pressure (MRP) (52+/- 23 mmHg) than patients with rectal prolapse (34 +/- 20 mmHg; P < 0.01). In the group of patients with rectal prolapse, there was a postoperative increase in MRP after six months (P < 0.001) but not after seven days. Maximum squeeze pressure (MSP) did not increase. Neither MRP nor MSP increased postoperatively in patients with internal rectal procidentia. Continence was improved postoperatively both in patients with rectal prolapse (P < 0.01) and rectal intussusception (P < 0.01). There was no postoperative increase in rectal emptying difficulties.

CONCLUSION

Ripstein's operation often improved anal continence in patients with rectal prolapse and rectal intussusception. This improvement was accompanied by increased MRP in patients with rectal prolapse, indicating recovery of internal anal sphincter function. No postoperative increase in MRP was found in patinets with rectal intussusception. This suggests an alternate mechanism of improvement in patients with rectal intussusception.

Neuromedin-N inhibits migrating myoelectric complex and induces irregular spiking in the small intestine of rats; comparison with neurotensin

The effects of neuromedin-N on migrating myoelectric complexes in the small intestine of rats were studied. As neuromedin-N and neurotensin are structurally related peptides a comparison with neurotensin was made. Myoelectric activity was recorded by means of three bipolar electrodes implanted into the wall of the small intestine at 5, 15 and 25 cm distal to the pylorus. The peptides were administered as intravenous infusions to fasted conscious rats. Neuromedin-N at doses of 100-800 pmol kg-1 min-1 caused a dose-dependent disruption of the migrating myoelectric complexes and induced irregular spiking activity (n = 7, P less than 0.05). Neurotensin induced a similar response, but at doses of 1.0-8.0 pmol kg-1 min-1 (n = 5, P less than 0.05). Thus, on a molar basis, neuromedin-N appeared to be about 100-times less potent than neurotensin. Hexamethonium (20 mg kg-1 i.v.) inhibited the migrating motor complexes and induced quiescence, but did not block the effect of neuromedin-N at a dose of 800 pmol kg-1 min-1. Atropine (1 mg kg-1 i.v.) and mepyramine (2 mg kg-1 i.v.) did not affect the migrating motor complexes, nor did they block the effect of neuromedin-N. Simultaneous infusion of neuromedin-N and neurotensin in a 1:1 molar ratio at doses of 2 pmol kg-1 min-1 showed inhibition of the response to neurotensin in eight out of ten experiments. In conclusion, neuromedin-N changes the myoelectric activity in the small intestine from a fasting to a fed pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Histamine secretion induced by neuromedin-N

Neuromedin-N dose-dependently stimulated the release of histamine from rat serosal mast cells and was 10 to 100 times less potent than neurotensin. The threshold concentration was 10(-6) M, and 10(-3) M neuromedin-N released 31% of the total cell histamine content. The histamine release induced by neuromedin-N was temperature-dependent with an optimum around 30-37 degrees C. Skin vascular permeability increased dose-dependently in response to intradermal injections of neuromedin-N and this peptide was 10 to 100 times less potent than neurotensin. Mepyramine inhibited the effect on vascular permeability suggesting that the effect of neuromedin-N was mediated via the release of histamine.

[Importance of the nonverbal characteristics of the speech signal for evaluating the mental and physical state of a pilot]

An analysis of the frequency, time and dynamics characteristics of the acoustic signal is one of the useful and reliable methods of objective assessment of the psychophysiological state of a pilot. The information conveyed through the nonverbal channel is nonspecific. The pattern of the stressor that causes a change in the pitch can be often identified only tentatively, if there is no additional information. The intensity of the stressor cannot be well correlated with the degree of the pitch change. The voice alters most seriously in response to psychic stressors and factors that affect adversely the normal merchanics of respiration (breathing at increased pressure, acceleration). The voice remains unaltered during an exposure to hypoxia and high ambient temperatures.