Optimized single-cell RNA sequencing protocol to study early genome activation in mammalian preimplantation development

Here, we present a modification of single-cell tagged reverse transcription protocol to study gene expression on a single-cell level or with limited RNA input. We describe different enzymes for reverse transcription and cDNA amplification, modified lysis buffer, and additional clean-up steps before cDNA amplification. We also detail an optimized single-cell RNA sequencing method for handpicked single cells, or tens to hundreds of cells, as input material to study mammalian preimplantation development. For complete details on the use and execution of this protocol, please refer to Ezer et al.1.

Tumour angiogenesis and mast cell density in the prognostic assessment of colorectal carcinomas

BACKGROUND

Tumour angiogenesis is essential for the growth, invasion and metastasis of solid tumours. There are several lines of evidence that the mast cells play an important role in tumour angiogenesis.

AIMS

The study focused to determine the correlation between the microvessel and mast cell densities, and to evaluate whether tumour angiogenesis and mast cell density could predict recurrence following curative surgery in patients with colorectal carcinomas.

PATIENTS

Microvessel and mast cell densities were investigated in tumour specimens from 60 patients with colorectal carcinoma.

METHODS

Microvessels were stained by immunohistochemical method using a monoclonal antibody anti-CD34. The routine Giemsa blue staining method was used to assess the mast cells. Microvessels and mast cells were counted in a x400 field.

RESULTS

The mean microvessel and mast cell counts were higher in patients with recurrence compared with those patients who were disease-free for at least 24 months (p<0.001). The Spearman's correlation coefficient revealed a significant correlation between mast cell and microvessel counts in colorectal carcinomas (r=0.684; p<0.001). Kaplan-Meier plots of survival showed that the high microvessel (>28) and mast cell (>6) counts correlated with a shorter disease-free survival (p=0.0003 and p=0.0013, respectively). Multivariate analysis showed that the depth of penetration (T4 versus T2) (p=0.004), liver metastasis (p=0.04) and microvessel density (p=0.003) were independent predictors of recurrence. In multivariate analysis, mast cell density did not reach significance.

CONCLUSIONS

Our results suggest that the microvessel density of the primary tumour may be an important independent predictor of tumour recurrence and time to recurrence in colorectal carcinomas. The significant correlation between mast cell and microvessel counts suggest that the mast cells may have a role in tumour progression via promoting angiogenesis.

The effect of Ginkgo biloba on the activity of catalase and lipid peroxidation in experimental strangulation ileus

This study was designed to assess the therapeutic effect of Ginkgo biloba extract (EGb 761) in experimental strangulation ileus. Rats were divided into control (n = 7), placebo (n = 11), and EGb-treated (n = 11) groups. No surgical procedure was carried out on the control group. Strangulation ileus was produced in the placebo and EGb groups for 2.5 h. At the end of this period, 100 mg/kg EGb in 1 ml of saline was injected intraperitoneally to the EGb-treated group. In the placebo group, animals received an equivalent amount of saline intraperitoneally; 24 h later, repeat laparotomies were performed to take blood and intestinal tissue samples. The EGb treatment decreased tissue malondialdehyde levels and increased catalase activities compared with the placebo group (P < 0.05 for both). Serum creatine kinase and phosphorus levels were also determined in all groups. In the placebo group these were significantly higher than in the control group (P < 0.01 and P < 0.05, respectively). In the EGb group these were not different from controls and the increase in creatine kinase activity in the EGb group was not as high as in the placebo group (P < 0.05). Our results suggest that EGb could be preventive against the effects of strangulation ileus in a rat model.

Beneficial effects of allopurinol on glutathione levels and glutathione peroxidase activity in rat ischaemic acute renal failure

The protective effect of allopurinol, an inhibitor of the enzyme, xanthine oxidase, against the renal ischaemia-reperfusion of the rat was investigated. Rats were subjected to renal ischaemia by clamping of the left renal artery and vein for 45 min, and were then reperfused for 24 h; these animals were randomized to receive either saline (n = 10) or allopurinol (n = 10) at a dose of 50 mg/kg bolus intraperitoneally 5 min before reperfusion. The control group comprised seven healthy rats not exposed to ischaemia or reperfusion. The blood urea nitrogen and plasma creatinine levels were increased in the allopurinol group, but the increase was less than that in the placebo group, compared with the controls. The kidney glutathione level was significantly reduced in the placebo group but not in the allopurinol group compared with the controls. The glutathione peroxidase activity in the kidney tissues was reduced more than two-fold in the placebo group compared with the controls, but the reduction in glutathione peroxidase was considerably less in the allopurinol group. Renal tissue lactate dehydrogenase, aspartate amino-transferase, gamma-glutamyl transferase and alkaline phosphatase activities were reduced almost two-fold in the placebo group, but allopurinol treatment maintained these enzyme activities close to the control activities. These results provide evidence that allopurinol treatment may have beneficial effects on antioxidant defences against ischaemia-reperfusion injury of rat kidneys.

Intravesical mitoxantrone for superficial bladder tumors

Thirty-five patients (33 males, median age 58) with stage T alpha (21 patients) or T1, grade 1 (17 patients) or grade 2 superficial bladder carcinoma, were treated with transurethral resection (TUR) followed by intravesical prophylactic therapy with 10 mg mitoxantrone administered weekly for 6 weeks and then monthly for 10 months. Twenty-five patients were newly diagnosed and 10 had relapsed after previous therapy. Diagnosis was confirmed with cytology and biopsy. The aim of the study was to evaluate the prophylactic effect (relapse rate, disease free interval) and toxicity of intravesical mitoxantrone in superficial bladder carcinoma. Relapses were established with biopsy. After a mean period of 12 months follow-up (median 8.3 months), 63% of patients in the whole group, 72% in the newly diagnosed group and 40% in the group of previously relapsed patients remained relapse free. These rates compare very favorably with the most effective prophylactic agents available. At the end of the follow-up period the median disease-free survival for the whole group was not reached. Therapy was well tolerated with no systemic toxicity and 14 patients reporting grade 1-2 local toxicity. In no patient was treatment discontinued due to toxicity. Mitoxantrone is an effective and safe agent for the post-TUR adjuvant intravesical therapy.

[Actinomycosis abscess developing in the rectus muscle. (One case history)]

A 36 year old male patient having an abscess in right rectus muscle's cover 2 years after stomach operation; attended to our hospital. The abscess was discharged. Following this, at 6 months intervals new abscess were formed in left lower and right upper rectus cover and discharged. Samples from abscess were routinely observed microbiologically and for tuberculosis; but the etiologic agent could not be identified. Six months later the patient attended to our hospital with abscess in right lower rectus cover again. The sample taken from the patient was examined thinking actinomycosis. After clinical and microbiological observation, the causative agent was identified as Actinomyces israeli.