Type IV renal tubular acidosis following resolution of acute kidney injury and disseminated intravascular coagulation due to hump-nosed viper bite

Hump-nosed viper bite can cause acute kidney injury (AKI) and disseminated intravascular coagulation. In some patients, it can cause chronic kidney disease necessitating life-long renal replacement therapy. Lack of effective antivenom makes the management of these patients difficult. A 51-year-old Sri Lankan male was admitted with AKI and disseminated intravascular coagulation following a hump-nosed viper bite. He made a complete recovery with blood product support and hemodialysis. Renal biopsy was performed as his renal recovery was prolonged which revealed patchy tubular atrophy and interstitial inflammation suggestive of subacute interstitial nephritis. Later, he presented with hyperkalemic paralysis and acidosis. A diagnosis of late onset type 4 renal tubular acidosis was made and he responded well to a course of fludrocortisone.

Fulminant Clostridium difficile colitis: a complication of perioperative antibiotic prophylaxis

Antibiotic prophylaxis for maxillofacial surgical wounds remains common practice. Surgeons must weigh the risks (e.g., Clostridium difficile colitis) against the benefits before administering antibiotics for any reason and the relative risk and morbidity of C difficile colitis against those of a potential postoperative wound infection. In addition, the possibility of C difficile infection as a complication of perioperative antibiotic prophylaxis should be discussed with patients before surgery, especially those with concomitant baseline risk factors. This report describes the case of a young healthy patient with few risk factors for C difficile infection who received a standard perioperative course of antibiotic therapy. Subsequently, the patient developed severe fulminant C difficile infection that required a protracted hospital admission, subtotal colectomy, and ileostomy. This case underscores that antibiotic prophylaxis continues in widespread use and is not benign therapy.

Use of the navigator probe after radiotracer injection to identify nonpalpable rib lesions requiring surgical resection

BACKGROUND

: Patients with nonpalpable rib lesions (NPRL) requiring biopsy present a challenging problem for the thoracic surgeon. Ideally, a small incision directly over the NPRL should be performed to minimize morbidity, particularly if the lesion is benign. The Navigator probe is routinely used after lymphoscintigraphy by surgical oncologists to isolate sentinel lymph nodes requiring removal, but can also be used to guide resection of nonpalpable focal rib lesions demonstrating increased technetium-99m hydroxymethylene diphosphonate (Tc-99m HDP) uptake. This report describes our initial experience with this technique.

METHODS

: Over a 5-month period, 3 patients with focal NPRL underwent rib resection. All patients had solitary lesions demonstrated on recently performed Tc-99m HDP bone scanning. Prior cancers were reported in 2 patients, and pain in 2 patients. Before surgery, all patients underwent intravenous injection of 20 to 25 mCi Tc-99m HDP at least 2 hours before the Navigator probe-guided procedure.

RESULTS

: The Navigator probe identified all 3 lesions, allowing a single 4 cm or smaller incision in all cases. Histology included metastatic breast cancer (1), pathologic fracture secondary to metastatic palatal cancer (1), and eosinophilic granuloma (1). No patient required further resection.

CONCLUSIONS

: Intraoperative localization of NPRL that are positive on Tc-99m HDP bone scanning using the Navigator probe is feasible and was 100% successful in our initial experience. This technique allows a minimally invasive approach, which is beneficial for those patients who do not require further resection.

American College of Chest Physicians and Society of Thoracic Surgeons consensus statement for evaluation and management for high-risk patients with stage I non-small cell lung cancer

BACKGROUND

The standard treatment of stage I non-small cell lung cancer (NSCLC) is lobectomy with systematic mediastinal lymph node evaluation. Unfortunately, up to 25% of patients with stage I NSCLC are not candidates for lobectomy because of severe medical comorbidity.

METHODS

A panel of experts was convened through the Thoracic Oncology Network of the American College of Chest Physicians and the Workforce on Evidence-Based Surgery of the Society of Thoracic Surgeons. Following a literature review, the panel developed 13 suggestions for evaluation and treatment through iterative discussion and debate until unanimous agreement was achieved.

RESULTS

Pretreatment evaluation should focus primarily on measures of cardiopulmonary physiology, as respiratory failure represents the greatest interventional risk. Alternative treatment options to lobectomy for high-risk patients include sublobar resection with or without brachytherapy, stereotactic body radiation therapy, and radiofrequency ablation. Each is associated with decreased procedural morbidity and mortality but increased risk for involved lobe and regional recurrence compared with lobectomy, but direct comparisons between modalities are lacking.

CONCLUSIONS

Therapeutic options for the treatment of high-risk patients are evolving quickly. Improved radiographic staging and the diagnosis of smaller and more indolent tumors push the risk-benefit decision toward parenchymal-sparing or nonoperative therapies in high-risk patients. Unbiased assessment of treatment options requires uniform reporting of treatment populations and outcomes in clinical series, which has been lacking to date.

Treatment of stage I lung cancer in high-risk and inoperable patients: comparison of prospective clinical trials using stereotactic body radiotherapy (RTOG 0236), sublobar resection (ACOSOG Z4032), and radiofrequency ablation (ACOSOG Z4033)

OBJECTIVE

The purpose of the present study was to compare the selection criteria and short-term outcomes among 3 prospective clinical trials using stereotactic body radiotherapy (Radiation Therapy Oncology Group [RTOG] trial 0236), sublobar resection (American College of Surgeons Oncology Group [ACOSOG] trial Z4032), and radiofrequency ablation (ACOSOG trial Z4033).

METHODS

The selection criteria and outcomes were compared among RTOG 0236 (n = 55), ACOSOG Z4032 (n = 211), and ACOSOG Z4033 (n = 51). Age, Eastern Cooperative Oncology Group performance status, percentage of predicted forced expiratory volume in 1 second, and percentage of predicted carbon monoxide diffusing capacity of the lung were used to perform a propensity-matched analysis among patients with clinical stage 1A in RTOG 0236 and ACOSOG Z4032.

RESULTS

The patients in ACOSOG Z4033 undergoing radiofrequency ablation were older (75.6 ± 7.5 years) than those in RTOG 0236 (72.5 ± 8.8 years) and ACOSOG Z4032 (70.2 ± 8.5 years; P = .0003). The pretreatment percentage of predicted forced expiratory volume in 1 second was 61.3% ± 33.4% for RTOG 0236, 53.8% ± 19.6% for ACOSOG Z4032, and 48.8% ± 20.3% for ACOSOG Z4033 (P = .15). The pretreatment percentage of predicted carbon monoxide diffusing capacity of the lung was 61.6% ± 30.2% for RTOG 0236, 46.4% ± 15.6% for ACOSOG Z4032, and 43.7% ± 18.0% for ACOSOG Z4033 (P = .001). The overall 90-day mortality for stereotactic body radiotherapy, surgery, and radiofrequency ablation was 0%, 2.4% (5/211), and 2.0% (1/51), respectively (P = .5). Overall, the unadjusted 30-day grade 3+ adverse events were more common with surgery than with stereotactic body radiotherapy (28% vs 9.1%, P = .004), although no difference was between the 2 groups at 90 days. Among the patients with clinical stage IA in ACOSOG Z4032, 29.3% had a more advanced pathologic stage at surgery. A propensity-matched comparison showed no difference between stereotactic body radiotherapy and surgery for 30-day grade 3+ adverse events (odds ratio, 2.37; 95% confidence interval, 0.75-9.90; P = .18).

CONCLUSIONS

Among appropriately matched patients, no difference was seen in early morbidity between sublobar resection and stereotactic body radiotherapy. These results underscore the need for a randomized trial to delineate the relative survival benefit of each modality and to help stratify patients considered high risk.

Randomized double-blind placebo-controlled crossover study to determine the effects of esomeprazole on inhibition of platelet function by clopidogrel

BACKGROUND

Pharmacokinetic studies suggest that clopidogrel and esomeprazole are metabolized by similar hepatic enzymes; however, previous studies have not identified a biochemical interaction.

OBJECTIVES

To determine whether addition of esomeprazole to patients receiving aspirin and clopidogrel reduces the antiplatelet effects of clopidogrel.

PATIENT/METHODS

Patients with a history of an acute coronary syndrome who had previously received clopidogrel were recruited. Subjects were commenced on clopidogrel and randomized to one of two treatment arms (esomeprazole or placebo) for 6 weeks. Following a 2-week washout period for study medications, patients were crossed over onto the alternative treatment arm for a further 6 weeks. Platelet function tests were undertaken at baseline, following the first treatment period, after washout and following the second treatment period.

RESULTS

Thirty-one patients were enrolled. Significant attenuation of clopidogrel's antiplatelet effects was seen with co-administration of esomeprazole compared with placebo. Vasodilator stimulated phosphoprotein (VASP), platelet aggregometry (area under the curve (AUC)) and VerifyNow results were 54.7% ± 2.8 platelet reactivity index (PRI), 66.3 ± 2.6 AUC units and 213.1 ± 14.1 platelet reactivity units (PRU) with esomeprazole vs. 47% ± 2.7 PRI, 59.7 ± 3.7 AUC units and 181.4 ± 14.6 PRU with placebo (P < 0.01 esomeprazole vs. placebo for all measures). There was no significant difference in platelet aggregometry (maximal aggregation) between the esomeprazole group (68.9% ± 2.7 units) and placebo-treated group (64.5% ± 4.1 units; P > 0.05).

CONCLUSION

Esomeprazole when co-administered with aspirin and clopidogrel results in a significant attenuation of clopidogrel's antiplatelet effects.

Proton pump inhibitors, genetic polymorphisms and response to clopidogrel therapy

Clopidogrel has become part of the mainstay of therapy for acute coronary syndromes and in patients post stenting. Clopidogrel is a pro drug and is metabolised by liver enzymes, particularly CYP2C19, into its active form. A considerable proportion of patients have a poor response to clopidogrel and this may be due to several factors. Genetic polymorphisms involved in clopidogrel's absorption, metabolism and activity at the platelet may interfere with its antiplatelet actions. Further, proton pump inhibitors (PPI) may interfere with clopidogrel's actions by functionally reducing the ability of CYP2C19 to convert clopidogrel to its active metabolite. By attenuating clopidogrel's actions, both polymorphisms and drug interactions may increase the risk of thrombotic events during clopidogrel therapy. This review will explore the current evidence relating to the association between PPIs, genetic polymorphisms and poor response to clopidogrel. Routine genetic testing cannot be recommended for patients receiving dual antiplatelet therapy (DAPT). However, it may have a role for patients with an episode of stent thrombosis, prior to planned high-risk stenting or major bleeding. Regarding concomitant clopidogrel and PPI therapy, it is recommended that only patients with previous gastrointestinal (GI) bleeding or multiple risk factors for GI bleeding should be prescribed gastroprotection. This is due to the uncertainty surrounding the clinical significance of this interaction given the discordant biochemical and clinical data, conflicting results from observational studies and the limitations of the COGENT study. Pantoprazole seems least likely to interact with clopidogrel and most suitable for use in patients receiving DAPT.

Pattern of expression of calpain subunits (large and small) in human breast cancer and the prognostic significance

21078

Background: Calpains belongs to family of non-lysosomal calcium dependent cysteine proteases which are known to regulate cellular migration, apoptosis and cell cycle progression in normal and tumour cells. Calpain has also been indicated in the metastatic process of certain tumours like RCC and identified as a potential tumor suppressor for gastric cancer. Little is known about the expression pattern of calpain in human breast cancer. The current study investigated the expression pattern of the large (calpainL) and small (calpainS) subunits of calpain which are encoded by different genes, in human breast cancer and attempted to correlate the expression with clinical outcome. Methods: RNA was extracted from frozen sections of breast tissue (n=120, median clinical follow up of the patients - 72 months) for gene amplification. The expression of both subunits of calpain was determined by using RT-PCR and quantitative RT-PCR. Statistical analysis was carried out using Mann- Whitney U test and the Kruskal- Wallis test. Results: We found significantly higher level of both calpain subunits in tumour tissue (n=120) as compared to normal non-neoplastic mammary tissues (calpainL, p=0.022 and calpainS, p=0.039). The expression of calpainL was significantly lower in patients with poor clinical outcome (with metastasis, p=0.024, with local recurrence, p=0.024 and who died of breast cancer, p=0.028), than those who were disease free. In contrast, the levels of calpainS were high in patients with poor prognosis, metastasis and who died of breast cancer but were statistically not significant. The expression of calpainL was marginally lower in node positive tumours than the node negative tumours. CalpainS transcripts were higher in node positive than node negative tumours (p=0.23). Similarly, calpainL showed a low level in high grade tumours whereas calpainS displayed a contrasting high level in these tumours. Conclusions: The large and small subunits of calpain have a distinct pattern of expression in human breast cancer. A decrease expression of calpainL but an increase expression of calpainS may be associated with poor prognostic tumours, thus indicating the intimate nature of the molecular pair in the disease progression of human breast cancer.

No significant financial relationships to disclose.

Expression of the WAVE (WASP Verprolin-homologous) molecules in human breast cancer

21061

Background: WAVEs (WASP Verprolin-homologous) belongs to the CCN family which comprises of nine members, the cysteine-rich 61 (Cyr61/CCN1), connective tissue growth factor (CTGF/CCN2) and nephroblastoma over-expressed (Nov/CCN3), Wnt-induced secreted proteins(WISPs)1, 2 and 3 (CCN4–6) as well as the WAVE-1,2 and 3 (also known as CCN7–9 respectively). Some members of the CCN family, such as Cyr61 and CTGF are known to stimulate mitosis, adhesion, apoptosis, extracellular matrix production, cell migration and growth arrest in cancer cells including breast cancer cells. However, there is no knowledge of the expression pattern and the function of WAVEs in human breast cancer. Here, we report the expression of WAVE-1,-2 and -3 transcripts and proteins in relation to clinical and pathological characteristics in human breast cancer. Methods: The expression of the three WAVE molecules at the mRNA and protein levels in a cohort of 122 human breast cancers and 32 normal breast tissues were analysed and correlated with the patients’ clinical outcome. The respective transcripts were quantitative determined using real time RT-PCR and distribution of the proteins were investigated by immunohistochemical methods. Results: All three WAVE proteins were detected in mammary epithelial cells and are of cytoplasmic nature. Breast cancer cells from the tissues also displayed positive staining of the WAVE proteins, with WAVE-2 staining appears weaker compared with normal epithelial cells. WAVE-1 transcripts were expressed in significantly high levels (p=0.03) in high grade breast cancers. Low levels of WAVE-2 were associated with higher TNM staging (p=0.038 in TNM3 and p=0.017 in TNM4) and were also found in patients with poor prognosis. Interesting, a marginal reduction of WAVE-3 transcripts was seen in patients who developed systemic metastasis. No other significant associations were found between the WAVE1 and WAVE3 transcripts and the breast cancer cells. Conclusions: WAVEs are widely expressed in human mammary tissues and have a differential expression in human breast cancer with WAVE2 appearing to be associated with the aggressiveness of breast tumors.

No significant financial relationships to disclose.

Minimally invasive esophagectomy: state of the art

Open esophagectomy is associated with significant mortality and morbidity, even in experienced centers. Two of the more frequent complications following esophagectomy are pneumonia and respiratory failure. Single-institution series have suggested that the incidence of these complications may be decreased with minimally invasive esophagectomy, with equivalent survival compared to open esophagectomy. However, this operation is technically challenging. In this review we detail the procedure as performed in our center, and also discuss some recent developments.

Sublobar resection for the subcentimeter pulmonary nodule

Several studies have demonstrated an increased local recurrence rate with sublobar resection (SR) when compared with lobar resection for the treatment of non-small-cell lung cancer (NSCLC). Therefore, lobectomy has remained the gold standard therapy for NSCLC with lesser resection reserved as a compromise operation for high-risk patients. The increased identification of small NSCLC tumors by CT scan is leading many surgeons to question the appropriateness of lobectomy for these tumors. There has been increasing interest by many surgeons to use SR as intentional therapy for patients with small peripheral NSCLC. This article reviews the recent literature and evidence supporting intentional SR for NSCLC. Although lobectomy should continue to be regarded as the procedure of choice for NSCLC, we believe that a subset of patients with favorable characteristics may be appropriately treated with intentional SR as long as good assessment of nodal involvement is made. Future investigation is required to better define when SR is appropriate.

NMDA receptor blockade and hippocampal neuronal loss impair fear conditioning and position habit reversal in C57Bl/6 mice

The interpretation of learning and memory deficits in transgenic mice has largely involved theories of NMDA receptor and/or hippocampal function. However, there is little empirical data that describes what NMDA receptors or the hippocampus do in mice. This research assessed the effects of different doses of the NMDA receptor antagonist, MK-801, or different-sized hippocampal lesions on several behavioral parameters in adult male C57Bl/6 mice. In the first set of experiments, different doses of MK-801 (0.05-0.3mg/kg, s.c.) were assayed in fear conditioning, shock sensitivity, locomotion, anxiety, and position habit reversal tests. Contextual and cued fear conditioning, and position habit reversal were impaired in a dose-dependent manner. Locomotor activity was increased immediately after injection of the highest dose of MK-801. A second set of experiments determined the behavioral effects of a moderate and large excitotoxic hippocampal lesion. Both lesions impaired contextual conditioning, while the larger lesion interfered with cued conditioning. Reversal learning was significantly diminished by the large lesion, while the moderate lesion had a detrimental effect at a trend level (P<0.10). These results provide important reference data for studies involving genetic manipulations of NMDA receptor or hippocampal function in mice. Furthermore, they serve as a basis for a non-transgenic mouse model of the NMDA receptor or hippocampal dysfunction hypothesized to occur in human cognitive disorders.