Characterization of the extended-spectrum beta-lactamase reference strain, Klebsiella pneumoniae K6 (ATCC 700603), which produces the novel enzyme SHV-18

Klebsiella pneumoniae K6 (ATCC 700603), a clinical isolate, is resistant to ceftazidime and other oxyimino-beta-lactams. A consistent reduction in the MICs of oxyimino-beta-lactams by at least 3 twofold dilutions in the presence of clavulanic acid confirmed the utility of K. pneumoniae K6 as a quality control strain for extended-spectrum beta-lactamase (ESBL) detection. Isoelectric-focusing analysis of crude lysates of K6 demonstrated a single beta-lactamase with a pI of 7.8 and a substrate profile showing preferential hydrolysis of cefotaxime compared to ceftazidime. PCR analysis of total bacterial DNA from K6 identified the presence of a bla(SHV) gene. K6 contained two large plasmids with molecular sizes of approximately 160 and 80 kb. Hybridization of plasmid DNA with a bla(SHV)-specific probe indicated that a bla(SHV) gene was encoded on the 80-kb plasmid, which was shown to transfer resistance to ceftazidime in conjugal mating experiments with Escherichia coli HB101. DNA sequencing of this bla(SHV)-related gene revealed that it differs from bla(SHV-1) at nine nucleotides, five of which resulted in amino acid substitutions: Ile to Phe at position 8, Arg to Ser at position 43, Gly to Ala at position 238, and Glu to Lys at position 240. In addition to the production of this novel ESBL, designated SHV-18, analysis of the outer membrane proteins of K6 revealed the loss of the OmpK35 and OmpK37 porins.     

Is Fourth Port Really Required in Laparoscopic Cholecystectomy?

Since the advent of four-port laparoscopic cholecystectomy, many modifications regarding port number and size have been tried. The feasibility of three-port technique has been found comparable to the conventional four-port laparoscopic cholecystectomy. To assess the feasibility and safety of three-port laparoscopic cholecystectomy in a prospective study. Between March 2007 and March 2009, fifty patients with cholelithiasis aged between 15 and 56 years underwent three-port cholecystectomy in a prospective study in Government medical college, Srinagar. A single surgeon did all the cases and there was no criterion for the patient selection. These were consecutive fifty surgeries done by the surgeon. The outcome was assessed in terms of intra-operative and post-operative parameters. The mean (range) age was 45 (15–56) years and there were thirty-nine females and eleven males in the study. All the procedures were completed successfully without any conversions to open or any major complications; though three patients needed the addition of a fourth port as in conventional laparoscopic cholecystectomy. The mean (range) operative time was 55 (30–90) min and the average blood loss was 30 ml. The mean (range) hospital stay was 1 (1–3) days. All patients returned to routine work within 1 week of surgery. The mean follow-up was 5 (2–7) months. We conclude, from the results above, that three-port laparoscopic cholecystectomy is safe and feasible. There are only two visible surgical scars, better cosmetic appearance with no increased risk of bile duct injury. It reduces the manpower in the form of a second assistant. Thus, it can be recommended as a safe alternative procedure to conventional four-port laparoscopic cholecystectomy.     

Significance of hemolysis on extracorporeal life support after cardiac surgery in children

Hemolysis is common during extracorporeal life support (ECLS). Elevated levels of circulating plasma free hemoglobin (FHb) has been linked to the development of hemoglobinuria nephropathy. Its clinical significance in patients receiving ECLS remains unknown. Medical records of 104 children <3 years old who required ECLS after repair of congenital heart disease were reviewed. Forty-two patients required continuous renal replacement therapy (CRRT) during ECLS (CRRT group), and 62 patients did not (no-CRRT group). For all patients, FHb level and the degree of fluid overload at the end of ECLS predicted the mortality rate during ECLS. Compared with the no-CRRT group, the CRRT group had a higher mortality rate during ECLS, a higher peak FHb level during ECLS, a higher FHb level at the end of ECLS, and more days of ECLS. In the CRRT group, the FHb level at the end of ECLS predicted death during ECLS. In the no-CRRT group, the peak FHb level was associated with a worse renal function. In conclusion, elevated FHb levels were associated with renal dysfunction and death during ECLS in children undergoing cardiac surgery. Further studies are needed to elucidate the cause–effect relationship in our findings.     

Chemo-radiotherapy: an alternative to surgery for squamous cell carcinoma of the rectum – report of six patients and literature review

Purpose  Since 1943 [ 1 ], only 45 patients of squamous cancer of the rectum have been reported in the published reports and the largest series to date consists of 12 patients. Reports suggest that the primary treatment is surgical resection but, in the light of nonsurgical advances in the treatment of anal squamous cell carcinoma (SCC), we present a review of the literature and report six patients treated by chemoradiation therapy (CRT).
Method  A literature search was undertaken using the keywords squamous cell, epidermoid, basaloid and cloacagenic and cancer of rectum and colon to provide evidence for this discussion from studies of surgery, radiation therapy and CRT in rectal SCC. A prospective database of the Mount Vernon Cancer Centre, UK was searched from 1995 to 2005 for patients diagnosed with pure SCC of the rectum.
Results  Six patients with histologically confirmed primary SCC of the rectum were treated with primary combination chemo-radiotherapy according to protocols used for SCC of the anal canal over a 15-year period. Surgery was avoided in four, and they remain disease-free on follow-up.
Conclusions  Primary CRT, as currently utilized in anal cancer, can be extended to primary SCC of the rectum.     

Rare and fatal complication of Gianturco tracheobronchial stent

Tracheobronchial stents are increasingly being used for the management of compromised large airways. Traditionally they have been used to palliate malignant conditions; however, they are now being used more frequently for nonmalignant conditions. The use of Gianturco self-expanding metal stent (William Cook, Bjaeverskov, Denmark) has been challenged for treatment of tracheobroncheomalacia, as fracture of the metal work could prove fatal. In this report we describe a case of fracture in the metal framework of a Gianturco stent resulting in recurrent pneumothoraces; heralding fatal haemoptysis as a result of perforation of the left subclavian artery.     

Assessment of microvessel density and carbonic anhydrase-9 (CA-9) expression in rectal cancer

Aim

The mechanism by which neoplasias respond to hypoxia determines their biological behavior and prognosis. Understanding the biology of tumors under hypoxic conditions is crucial for the development of anti-angiogenic therapy. Using the largest cohort of rectal adenocarcinomas to date, this study aimed to assess microvessel density (MVD) and carbonic anhydrase-9 (CA-9) expression and to correlate the results with recurrence and cancer-specific survival.

Materials and methods

Patients (n=101) who underwent surgery for rectal adenocarcinoma without previous neoadjuvant therapy or metastatic disease were selected. MVD and CA-9 expression were assessed immunohistologically by using the CD34 antibody and the MN/CA9 M75 antibody, respectively. In a multifactorial analysis, the results were correlated with tumor stage, recurrence rate, and long-term survival.

Results

MVD was higher with increased T- and N-stages (p<0.01) and associated positively with poor survival (hazard ratio (HR) 1.3 per 10 vessel increase, p<0.01). CA-9 was expressed in 73% of cancers. Negative lymph node status correlated with CA-9 positivity (p<0.05), reflected in a higher rate of CA-9 positivity in earlier Dukes’ stages (p<0.05). CA-9 positivity across tumor node metastasis (TNM) stages approached significance (Stage I/II: 80% CA-9 positive vs. 20% CA-9 negative; Stage III: 63% CA-9 positive vs. 37% negative, p=0.051). A trend was seen towards better cancer-specific survival in patients with CA-9 positive carcinomas (HR 0.51, p=0.07) on univariate analysis.

Discussion

MVD was higher in more advanced T- and N-stages and may be used as a determinant of survival in patients with rectal adenocarcinomas. CA-9 expression was seen more often in earlier Dukes’ stages, possibly representing an early tumor hypoxic response. CA-9 expression by adenocarcinoma cells may confer long-term survival advantage in surgically treated rectal cancer.     

Venous air embolism during the use of a Nd YAG laser

We report a case of a 47-year-old female who suffered a cardiac arrest during sub-mucosal diathermy of the inferior turbinate using a Nd YAG laser. The possible causes of the cardiac arrest are discussed. Venous air embolism due to Nd YAG laser was thought to be the most likely cause in this case. Although venous air embolism has previously been reported during nasal sinus surgery and choanal atresia when using a Nd YAG laser, the occurrence of this complication during a relatively minor surgical procedure has not previously been reported. It is important, therefore, to raise the awareness of this life threatening complication during use of a Nd YAG laser regardless of the duration of surgery. We recommend the use of appropriate methods and techniques to avoid this life threatening complication during the use of Nd YAG laser even for relatively short procedures.     

Functional imaging of colorectal cancer angiogenesis

Angiogenesis is a key factor in the growth and dissemination of colorectal cancer, with significant implications for its clinical management. Previous trials have provided proof-of-principle that inhibition of angiogenesis has the potential to enhance the effectiveness of treatment for this disease. Characterisation of the angiogenic status of the tumour on an individual patient basis could allow for a more targeted approach to treatment. In vivo imaging techniques that assess tumour microvessel function have the potential to improve the management of treatment for patients with colorectal cancer. This review focuses on MRI and CT assessment of colorectal cancer angiogenesis. We discuss the effects that these two techniques have had in the assessment of this disease, including tumour staging and therapeutic assessment. Their comparability with other imaging techniques, in particular ultrasound, and their limitations are also addressed.