Investigation of factors that cause insulin precipitation and/or amyloid formation in insulin formulations.

BACKGROUND: Multiple daily subcutaneous injections (MDSIs) are mainly used for formulating an insulin therapy for diabetic patients; however, they also cause insulin-derived amyloidosis (IDA) and lead to poor glycemic control. In addition, for the continuous subcutaneous insulin infusion system (CSII), precipitation frequently causes catheter occlusion and, if the precipitate in the formulations is amyloid, the injection of the insoluble amyloid into the subcutaneous tissue leads to IDA. The aim of this study was to conduct in vitro experiments and present a situation where insulin formulations cause precipitation and amyloid formation. METHODS: Humulin®R and NovoRapid® were used as model formulations for MDSIs and CSII, respectively. The generation of the precipitation was evaluated by measuring turbidity, and amyloid formation was evaluated by using Thioflavin T. Humulin®R was mixed with saline buffer solutions and glucose solutions to evaluate the effect of dilution. In addition, we created an experimental system to consider the effect of the time course of condition changes, and investigated the effects of insulin concentration, m-cresol existence, and pH change on the generation of the precipitate and amyloid in the formulation. RESULTS: In both the original and diluted formulations, physical stimulation resulted in the formation of a precipitate, which in most cases was an amyloid. The amyloid was likely to be formed at a near neutral pH. On the contrary, although a precipitate formed when the pH was decreased to near the isoelectric point, this precipitate was not an amyloid. Further decreases in pH resulted in the formation of amyloids, suggesting that both the positive and negative charged states of insulin tended to form amyloids. The formulation additive m-cresol suppressed amyloid formation. When additives were removed from the formulation, the amyloid-containing gel was formed in the field of substance exchange. CONCLUSIONS: To consider changes in conditions that may occur for insulin formulations, the relationship between the formation of precipitates and amyloids was demonstrated in vitro by using insulin formulations. From the in vitro study, m-cresol was shown to have an inhibitory effect on amyloid formation.

Safety and feasibility for single-incision laparoscopic cholecystectomy in local community hospital: a retrospective comparison with conventional 4-port laparoscopic cholecystectomy.

BACKGROUND: The aim of this study was to evaluate the safety and feasibility for single-incision laparoscopic cholecystectomy (SILC) by retrospective comparison with conventional laparoscopic cholecystectomy (CLC) in a local community hospital. METHODS: SILC was introduced and performed in 57 patients for benign gallbladder diseases. Their clinical data were compared with those of 62 patients treated with CLC. They included patient demographic data and operative outcomes. RESULTS: SILC was attempted in 57 patients and 52 cases (91.2%) were successfully completed. There were no statistical differences between the 2 groups in terms of operative time, blood loss, and postoperative complications. The length of hospital stay in the SILC group was significantly shorter compared with CLC (P < 0.0001). CONCLUSIONS: SILC has been successfully introduced in a local community hospital. The safety and feasibility was also confirmed. The SILC procedure may become 1 standard option for the treatment of benign gallbladder diseases.

A comparison of epidermal growth factor receptor expression in malignant peritoneal and pleural mesothelioma.

An evaluation of epidermal growth factor receptor (EGFR) phenotypic expression in malignant pleural and peritoneal mesothelioma was undertaken, using immunohistochemical (IHC) and fluorescence in situ hybridization (FISH) analysis. Thirty-eight malignant mesothelioma (MM) specimens were subjected to IHC staining and FISH to evaluate the expression of EGFR protein and gene status. Overall positive IHC reaction was detected in 20/38 (53%) cases, in 11/22 (50%) pleural MM, and in 9/16 (56%) peritoneal MM. Our study confirmed that EGFR membranous expression is a common feature in MM, but not in benign mesothelial lesion. Thirty-seven cases did not show a gene copy number gain. Only one case showed a copy number gain. The protein overexpression of EGFR was not related to a gene copy number gain.

Epidermal growth factor receptor mutations in malignant pleural and peritoneal mesothelioma.

BACKGROUND: Epidermal growth factor receptor (EGFR) gene mutation at the kinase domain and EGFR gene amplification are reported to be predictors of the response to EGFR tyrosine kinase inhibitors in lung cancer cases. In malignant mesothelioma (MM), the role of EGFR is less clear. METHODS: Thirty-eight MM specimens were submitted to EGFR mutation evaluation, and compared with the results of immunohistochemical staining and fluorescence in situ hybridization (FISH) analysis. DNA was extracted from paraffin blocks and PCR was performed to amplify exon regions 18-21 of the EGFR gene. Direct sequencing of the purified PCR products was performed. RESULTS: Five EGFR missense mutations were detected in six of the 38 patients (16%); two of these mutations were novel, two were originally detected in non-small cell lung carcinoma, and one resembled a location previously noted for malignant peritoneal mesothelioma. CONCLUSION: As far as the authors are aware there has been no report of the EGFR mutation of MM in Japanese cases, but in this study EGFR missense mutations were detected in some cases. EGFR mutation results were not related to immunohistochemical and FISH analysis.

[A case of local relapsed rectal cancer responding to low-dose S-1].

We report a case of local recurrent colorectal cancer that has been treated successfully with low-dose oral chemotherapeutic agent. An 80-year-old man underwent a low anterior resection for rectal cancer. Two years and nine months later, a recurrent tumor was revealed in the vicinity of the anastomotic region by colonoscopy. Additional examination by enhanced CT elucidated the tumor infiltrated the sacrum. For this reason, we planned an abdominoperineal resection of rectum with sacrum excision for treatment. However, we considered that he could not overcome the burden of operation for his complication. As a result of informed consent with the patient and his family, we decided a conservative treatment, and started chemotherapy using S-1. The tumor has been diminished slowly on enhanced CT and colonoscopy. The chemotherapy using S-1 has been continued with good quality of life for over five years. S-1 is expected to be an effective choice for the patient of colorectal cancer who cannot be taken the standard treatment for various reasons.

A new possibility for repairing the anal dysfunction by promoting regeneration of the reflex pathways in the enteric nervous system.

Moderate rectal distension elicits recto-rectal reflex contractions and simultaneous recto-internal anal sphincter reflex relaxations that together comprise the defecation reflex. Both reflexes are controlled by 1) pelvic nerves, 2) lumbar colonic nerves, and 3) enteric nervous system. The aim of the present study was to explore a novel approach to repairing the defecation reflex dysfunction by using the plasticity of enteric nervous pathways. Experiments were performed in anesthetized guinea pigs with ethyl carbamate. The rectum 30 mm oral from the anal verge was transected without damage to extrinsic nerves, and subsequent end-to-end one-layer anastomosis was performed. Recovery of the defecation reflex and associated reflex pathways were evaluated. Eight weeks after sectioning of intrinsic reflex nerve pathways in the rectum, the defecation reflex recovered to the control level, accompanied with regeneration of reflex pathways. The 5-HT(4)-receptor agonist mosapride (0.5 and 1.0 mg/kg) significantly (P < 0.01) enhanced the recovered defecation reflex 8 wk after surgery. Two weeks after local treatment with brain-derived neurotrophic factor (BDNF: 10(-6) g/ml) at the rectal anastomotic site, the recto-internal anal sphincter reflex relaxations recovered and some bundles of fine nerve fibers were shown to interconnect the oral and anal ends of the myenteric plexus. These results suggested a possibility for repairing the anal dysfunction by promoting regeneration of the reflex pathways in the enteric nervous system with local application of BDNF.