Hindlimb muscle morphology and function in a new atrophy model combining spinal cord injury and cast immobilization

Contusion spinal cord injury (SCI) animal models are used to study loss of muscle function and mass. However, parallels to the human condition typically have been confounded by spontaneous recovery observed within the first few post-injury weeks, partly because of free cage activity. We implemented a new rat model combining SCI with cast immobilization (IMM) to more closely reproduce the unloading conditions experienced by SCI patients. Magnetic resonance imaging was used to monitor hindlimb muscles' cross-sectional area (CSA) after SCI, IMM alone, SCI combined with IMM (SCI+IMM), and in controls (CTR) over a period of 21 days. Soleus muscle tetanic force was measured in situ on day 21, and hindlimb muscles were harvested for histology. IMM alone produced a decrease in triceps surae CSA to 63.9±4.9% of baseline values within 14 days. In SCI, CSA decreased to 75.0±10.5% after 7 days, and recovered to 77.9±10.7% by day 21. SCI+IMM showed the greatest amount of atrophy (56.9±9.9% on day 21). In all groups, muscle mass and soleus tetanic force decreased in parallel, such that specific force was maintained. Extensor digitorum longus (EDL) and soleus fiber size decreased in all groups, particularly in SCI+IMM. We observed a significant degree of asymmetry in muscle CSA in SCI but not IMM. This effect increased between day 7 and 21 in SCI, but also in SCI+IMM, suggesting a minor dependence on muscle activity. SCI+IMM offers a clinically relevant model of SCI to investigate the mechanistic basis for skeletal muscle adaptations after SCI and develop therapeutic approaches.

Abstract P4-09-07: ING1 Expression Measured by AQUA can be an Independent Prognostic Marker in Breast Cancer

Background: Breast cancer accounts for around 45,000 cancer related deaths in North America per year. The high incidence of breast cancer observed in this region is most likely due to the availability of various screening programs used to detect breast cancer, which otherwise may never get diagnosed. There is an inverse relation between the cost of treatment and patient survival as the breast cancer progresses to higher grades. Therefore, screening and diagnosing breast cancers at earlier stages is needed which can improve patient survival.

The INhibitor of Growth (ING) family of tumour suppressor proteins are implicated in diverse cellular processes including chromatin remodelling and apoptosis. ING proteins are stoichiometric members of histone acetyl transferase (HAT) and histone deacetylase (HDAC) complexes. Their expression is downregulated in several cancers, including breast carcinoma. Alternatively, ING function may be compromised by mislocalization to the cytoplasm. However, the association of expression of ING proteins and cancer specific survival has not been studied yet. In this study, we aimed to evaluate the prognostic significance of ING1 in breast cancer.

Patients and Methods: This study included 443 Breast Cancer patients diagnosed in Calgary, Canada from 1985–2000. Clinical data were obtained from the Alberta Cancer Registry and chart review. Tissue microarrays (TMAs) were assembled from triplicate cores of formalin-fixed paraffin-embedded tumour tissue. ING1 protein expression was quantified using fluorescent immunohistochemistry and automated quantitative analysis (AQUA) in normal breast epithelial cells and breast cancer samples. 5 year progression free survival (PFS) was analyzed using Kaplan-Meier plots and Cox proportional hazard modelling.

Results: In our study, we found that ING1 expression is significantly downregulated in the breast cancer patient samples relative to normal breast epithelia. High or low ING1 cytoplasmic/nuclear (C/N) ratio results in poor 5 year PFS. Also, the low tumor/stromal (t/s) ratio of ING1 results in poor prognosis. In univariate analysis, t/s ING1 expression showed a negative correlation with tumor stage [p = 0.008]; tumor grade [p = 0.000]; nodal status [p = 0.000] and 5 year PFS [p = 0.004]. However, no correlation was observed with ER, PR or HER2 status. In multivariate analysis, t/s ING1 proved to be an independent and better prognostic marker [HR 0.582, p = 0.037] than HER2 [HR 2.230, p = 0.057]; Age at diagnosis [HR 2.010, p = 0.205] and tumor size [HR 1.471, p = 0.189].

Discussion and Conclusions: This is the first study to evaluate ING1 expression in breast cancer using the AQUA technique. ING1 expression high or low in the C/N ratio might disrupt the stoichiometry of chromatin-modifying complexes and hamper ING1s extra nuclear functions, leading to poor survival. The significantly improved survival observed in patients with high t/s ING1 expression further strengthens the role of ING1 as a tumor suppressor.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-09-07.

Central pontine myelinolysis without hyponatraemia

A 55-year-old woman with a history of excess alcohol intake presented to the acute medical unit following concerns regarding her electrolyte disturbances. During correction of the electrolytes, the patient developed central pontine myelinolysis. The unusual features in the case were the absence of hyponatraemia which is usually associated with central pontine myelinolysis and also the good recovery that the patient made. Looking at the electrolyte changes, we suspect there may be a link to the rapid osmotic shifts occurring during refeeding and central pontine myelinolysis.

A review of tumour lysis syndrome with targeted therapies and the role of rasburicase

WHAT IS KNOWN AND OBJECTIVE

Tumour lysis syndrome (TLS) is an oncologic emergency with potentially devastating consequences classically associated with cytotoxic chemotherapy. In recent years, molecularly targeted drugs have assumed an increasingly important role in cancer therapeutics. The possibility of TLS is often overlooked in this setting. Rasburicase, a recombinant urate oxidase, is remarkably effective in treating hyperuricemia, thought to be central to the pathogenesis of renal injury in TLS. Our objective is to review the literature on TLS especially as it pertains to targeted therapies and summarize current knowledge and provide future directions regarding the role of rasburicase in the management of TLS.

METHODS

A MEDLINE search was conducted using PubMed and the keyphrase 'tumor lysis syndrome' to identify articles describing TLS with a broad range of novel anti-cancer agents. Meeting abstracts were also reviewed. Additionally, the biomedical literature was searched using the keyword 'rasburicase'.

RESULTS AND DISCUSSION

Tumour lysis syndrome has been described with nearly every class of 'targeted therapy'. This is not surprising as any drug causing death of cancer cells by any mechanism may lead to TLS in the appropriate setting. Although there is a wealth of evidence suggesting that rasburicase is extremely effective in correcting hyperuricemia, prospective trials showing that it improves hard outcomes such as acute renal failure, need for dialysis and mortality are lacking. Furthermore, much lower doses and durations of therapy than approved appear to be effective in controlling hyperuricemia, potentially leading to enormous cost savings.

WHAT IS NEW AND CONCLUSION

Any effective cancer therapy can lead to TLS. Physicians should consider the risk of TLS on a case-by-case basis and determine appropriate prophylaxis. The role of rasburicase continues to evolve. Randomized controlled trials evaluating clinically relevant outcomes are needed.

Response of AIDS-related plasmablastic lymphoma (PBL) to bortezomib

e19562

PBL are a group of highly aggressive neoplasms originally described in the oral cavity and jaws of HIV-infected patients. An AIDS-defining illness, PBL comprises 2.6% of AIDS-related lymphomas. PBL are best distinguished by their unique immunophenotype. They are terminally differentiated B-cell neoplasms, and typically lack common B-cell markers but uniformly express plasma cell markers. We report the first case of PBL that responded to bortezomib. A 42-year-old male with newly diagnosed AIDS presented with nausea, vomiting, bloody diarrhea and epigastric pain. EGD with biopsy revealed a high-grade PBL of the stomach. Flow cytometry was negative for CD45 and all common epithelial, T-cell and B-cell markers, but was positive for CD138 and p63(VS38c). Karyotyping revealed t(8;14), amongst other abnormalities. PET/CT showed significant hypermetabolism in multiple thoracic and abdominal lymph nodes, the left lung, liver and several bones. The diagnosis was stage IVBE PBL. Highly active anti-retroviral therapy was begun. Anthracycline-based chemotherapy was avoided due to persistent hyperbilirubinemia. Bortezomib was then administered at a dose of 1.3 mg/m2 IV on days 1, 4, 8 and 11. PET/CT on day 7 showed a marked decrease in hypermetabolism after only 2 doses, signifying a dramatic treatment response. After a total of 4 doses of bortezomib, he unfortunately succumbed to severe septic shock before a repeat PET/CT could be obtained. The prognosis of PBL is poor, with a median survival of about 6 months in most series. The WHO classifies PBL as a variant of diffuse large B-cell lymphoma. Accordingly, CHOP and CHOP-like regimens have mostly been used. However, studies of their immunophenotype and molecular histogenesis suggest that PBL are more closely related to plasma cell neoplasms. Bortezomib is a proteasome inhibitor widely used in multiple myeloma and mantle cell lymphoma. We chose bortezomib based on our patient's poor performance status and immune function, the desire to avoid combination chemotherapy, and translocations involving the immunoglobulin heavy chain gene locus (8;14) similar to those seen in multiple myeloma(4;14, 14;16) and mantle cell lymphoma(11;14). A shift in the paradigm of treatment of PBL towards agents effective in plasma cell malignancies may be necessary.

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Three-day regimen improves faecal tagging for minimal preparation CT examination of the colon

This study set out to determine whether extending the length of oral contrast administration in minimal preparation CT of the colon improves faecal tagging. Two cohorts of 50 patients each were compared, one with a 2-day the other with a 3-day faecal tagging regimen. The degree of faecal tagging was graded by two blinded observers. The 3-day regimen showed significantly better tagging in the rectum and sigmoid colon (p = 0.006 and p = 0.009, respectively, using the Mann-Whitney test). The percentage of patients who had faecal tagging in the sigmoid colon graded as "complete" was 64% for the 3-day regimen as opposed to 34% for the 2-day regimen. The corresponding percentages for the rectum were 64% for the 3-day regimen and 36% for the 2-day regimen. Extending the length of oral contrast administration from 2 to 3 days significantly improves the quality of faecal tagging in the rectum and sigmoid colon.

Occurrence of synchronous invasive lobular breast carcinoma and poorly differentiated ovarian carcinoma in a single peritoneal deposit

The synchronous occurrence of breast and ovarian cancers within individual omental metastases has not been reported in the available medical literature. We report such a finding in a patient with previously diagnosed invasive lobular carcinoma of the right breast. After 5 years of surveillance and disease-free interval, there was development of ovarian cancer, ascites and peritoneal metastases. Ultrasound-guided biopsy of a peritoneal metastasis confirmed dual histology from breast and ovarian carcinoma. Despite the presence of a prolonged disease-free survival from the primary breast cancer, the subsequent finding of advanced ovarian cancer highlights the potential diagnostic and therapeutic dilemmas which persist in the management of these patients.

An epidemiologic study of mild cognitive impairment in Kolkata, India

OBJECTIVES

To estimate the prevalence of two types of mild cognitive impairment (MCI)-amnestic and multiple domain types-among nondemented and nondepressed elderly subjects aged 50 and older.

METHODS

The study was carried out in Kolkata, the eastern metropolis of India. A cross-sectional community screening was carried out, and 960 subjects were selected by systematic random sampling for the assessment of cognitive function with the help of a validated cognitive questionnaire battery administered through house-to-house survey. A case-control study was also undertaken to identify potential risk factors through univariate analysis.

RESULTS

Ultimately, full evaluation of cognitive function was possible in 745 of 960 subjects. An overall prevalence of MCI detected based on neuropsychological testing was 14.89% (95% CI: 12.19 to 17.95). Prevalence of the amnestic type was 6.04% (95% CI: 4.40 to 8.1) and that of the multiple domain type was 8.85% (95% CI: 6.81 to 11.32). Adjusted for age, education. and gender, the amnestic type was more common among men and the multiple domain type among women with advancement of age. Rates differed considerably with educational attainment. Hypertension and diabetes mellitus were the major risk factors for both types of MCI.

CONCLUSION

In this first community-based study of mild cognitive impairment (MCI) from India, prevalence of the amnestic type is comparable with and that of the multiple domain type is less than the prevalence in developed countries. Variations in age, education, and gender specific prevalence of MCI of both types were encountered. The putative risk factors identified merit further study.

Changes in soleus muscle function and fiber morphology with one week of locomotor training in spinal cord contusion injured rats

The purpose of this study is two-fold: (1) to examine skeletal muscle function in a rat model of midthoracic contusion spinal cord injury (SCI) and (2) to evaluate the therapeutic influence of a short bout (1 week) of treadmill locomotor training on soleus muscle function (peak force, fatigability, contractile properties, fiber types), size (fiber area), and motor deficit and recovery (BBB scores) after SCI. The rats were injured with a moderate T8 spinal cord contusion and were assigned to either receive treadmill locomotor training (TM), starting 1 week after SCI for 5 consecutive days (20 min/trial, 2 trials/day) or not to receive any exercise intervention (no TM). Locomotor training resulted in a significant improvement in overall locomotor function (32% improvement in BBB scores) when compared to no TM. Also, the injured animals that trained for 1 week had 38% greater peak soleus tetanic forces (p < 0.05), a 9% decrease in muscle fatigue (p < 0.05), 23% larger muscle fiber CSA (p < 0.05), and decreased immunoexpression of fast heavy chain fiber types than did rats receiving no TM. In addition, there was a good correlation (0.704) between the BBB scores of injured animals and peak soleus muscle force regardless of group assignment. No significant differences were seen in twitch or time to peak tension values across groups. Collectively, these results indicate that 1 week of treadmill locomotor training, initiated early after SCI, can significantly improve motor recovery following SCI. The magnitude of these changes is remarkable considering the relatively short training interval and clearly illustrates the potential that initiating treadmill locomotor training shortly after injury may have on countering some of the functional deficits resulting from SCI.

Improving the accuracy of estimated blood loss at obstetric haemorrhage using clinical reconstructions

OBJECTIVES

Following the results of the Confidential Enquiries into Maternal Deaths report, which claims two maternal deaths annually in the UK from postpartum haemorrhage, our aim was to assess the accuracy of 'visual estimation of blood loss' and produce suitable pictorial and written algorithms to aid in the recognition and management of massive obstetric haemorrhage.

DESIGN

Observational study to determine discrepancy between actual blood loss (ABL) and estimated blood loss (EBL).

SETTING

Teaching hospital.

POPULATION

Hundred and three obstetricians, anaesthetists, midwives, nurses and healthcare assistants.

METHODS

Clinical scenarios were reproduced in the form of 12 Objective Structured Clinical Examination (OSCE) style stations augmented with known volumes of whole blood. Individual staff estimated the blood loss visually and recorded their results. Digital photographs were used to produce a pictorial 'algorithm' suitable for use as a teaching tool in labour ward.

MAIN OUTCOME MEASURES

Areas of greatest discrepancy between EBL and ABL.

RESULTS

Significant underestimation of the ABL occurred in 5 of the 12 OSCE stations: 500-ml (50-cm diameter) floor spill, 1000-ml (75-cm diameter) floor spill, 1500-ml (100-cm diameter) floor spill, 350-ml capacity of soaked 45- x 45-cm large swab and the 2-l vaginal postpartum haemorrhage on bed/floor.

CONCLUSIONS

Accurate visual estimation of blood loss is known to facilitate timely resuscitation, minimising the risk of disseminated intravascular coagulation and reducing the severity of haemorrhagic shock. Participation in clinical reconstructions may encourage early diagnosis and prompt treatment of postpartum haemorrhage. Written and pictorial guidelines may help all staff working in labour wards.