Extraction and Reconstitution of Photosystem II

Hill activity (oxygen evolution with ferricyanide as the electron acceptor), light-induced absorbance changes at liquid nitrogen temperature associated with the primary activity of photosystem II, and fluorescence yield changes at both low temperature and room temperature were measured with lyophilized spinach chloroplasts before and after extraction with hexane and reconstitution with beta-carotene and plastoquinone A. Extraction eliminated the Hill activity, and both beta-carotene and plastoquinone A were required for maximal restoration of activity to the reconstituted chloroplasts.Extraction also eliminated the light-induced absorbance changes at -196 C due to the photoreduction of C-550 and photooxidation of cytochrome b(559), and reconstitution with beta-carotene and plastoquinone A restored the low temperature photoreactions. However, only beta-carotene was essential for the restoration of the photoreactions. Cytochrome b(559) was modified, as a result of the extraction, to a lower redox potential, autooxidizable form and remained as such after reconstitution with beta-carotene. The beta-carotene-restored chloroplasts showed the photoreduction of C-550 but not the photooxidation of cytochrome b(559) because the cytochrome was already oxidized. When beta-carotene-reconstituted chloroplasts were suspended in buffer containing ascorbate prior to freezing, the cytochrome b(559) was reduced and could be photooxidized by irradiation at low temperature. After reconstitution with beta-carotene plus plastoquinone A the cytochrome b(559) was partially restored to its original high potential form and was in the reduced state so that both the photoreduction of C-550 and the photooxidation of cytochrome b(559) occurred on irradiation of the beta-carotene plus plastoquinone A-reconstituted chloroplasts. Reconstitution with plastoquinone A alone had essentially no effect on restoring the photoreactions.The fluorescence yield of dark-adapted lyophilized chloroplasts at -196 C showed an irreversible increase of about 2.5-fold during irradiation. After extraction the fluorescence yield of the chloroplasts was high (at the maximal light-induced level of the lyophilized control chloroplasts) and showed very little change in the light. Reconstitution with beta-carotene alone restored some fluorescence quenching which was relieved by irradiation at low temperature. Reconstitution with plastoquinone A alone restored a high degree of quenching, but this quenching was not relieved by light at low temperature. Fluorescence emission spectra at -196 C showed that the fluorescence of variable yield in the lyophilized and beta-carotene-reconstituted chloroplasts involved only the 680 and 695 nm emission bands but not the larger 730 nm emission band, whereas the irreversible quenching in plastoquinone A-reconstituted chloroplasts involved all wavelengths of emission. Extraction of the chloroplasts also eliminated the sharp 695 nm emission band at low temperature, and reconstitution with beta-carotene partially restored it.The fluorescence yield changes at room temperature differed from the low temperature measurements in that the strong fluorescence quenching restored to the plastoquinone A-reconstituted chloroplasts was relieved by light and reappeared in the dark. Thus plastoquinone A appeared to be much more effective than beta-carotene in restoring the fluorescence of variable yield in room temperature measurements. However, it is argued from the results at low temperature that the quenching in plastoquinone A-reconstituted chloroplasts, which is probably due to the oxidized form of the quinone, is nonspecific and a different quenching mechanism from that which obtains in normal chloroplasts.The results suggest that extraction with hexane removes plastoquinone A, which interrupts electron transport, and beta-carotene, which disrupts the primary photochemical activity of photosystem II. Reconstitution of the extracted chloroplasts with beta-carotene alone restores C-550 and the primary photochemical activity of photosystem II, and when the photosystem II reaction centers are restored the additional requirement of plastoquinone A for the Hill reaction can be demonstrated.

Redox potential of plastoquinone A in spinach chloroplasts

The redox potential of plastoquinone A in spinach chloroplasts was determined. The midpoint potential of the quinone is about +80 mV at pH 7.0 with an n value of 2. The pH-dependence of the potential is -30 mV per pH between pH 4.0 and 5.7, and -60 mV per pH between pH 5.7 and 8.0. The change of the slope at pH 5.7 is interpreted as the protonation of the oxidized plastoquinone A.

p53 protein regulates Hsp90 ATPase activity and thereby Wnt signaling by modulating Aha1 expression

The p53 tumor suppressor gene encodes a homotetrameric transcription factor which is activated in response to a variety of cellular stressors, including DNA damage and oncogene activation. p53 mutations occur in >50% of human cancers. Although p53 has been shown to regulate Wnt signaling, the underlying mechanisms are not well understood. Here we show that silencing p53 in colon cancer cells led to increased expression of Aha1, a co-chaperone of Hsp90. Heat shock factor-1 was important for mediating the changes in Aha1 levels. Increased Aha1 levels were associated with enhanced interactions with Hsp90, resulting in increased Hsp90 ATPase activity. Moreover, increased Hsp90 ATPase activity resulted in increased phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β), leading to enhanced expression of Wnt target genes. Significantly, levels of Aha1, Hsp90 ATPase activity, Akt, and GSK3β phosphorylation and expression of Wnt target genes were increased in the colons of p53-null as compared with p53 wild type mice. Using p53 heterozygous mutant epithelial cells from Li-Fraumeni syndrome patients, we show that a monoallelic mutation of p53 was sufficient to activate the Aha1/Hsp90 ATPase axis leading to stimulation of Wnt signaling and increased expression of Wnt target genes. Pharmacologic intervention with CP-31398, a p53 rescue agent, inhibited recruitment of Aha1 to Hsp90 and suppressed Wnt-mediated gene expression in colon cancer cells. Taken together, this study provides new insights into the mechanism by which p53 regulates Wnt signaling and raises the intriguing possibility that p53 status may affect the efficacy of anticancer therapies targeting Hsp90 ATPase.

Worse Preoperative Status Based on Inflammation and Host Immunity Is a Risk Factor for Surgical Site Infections in Colorectal Cancer Surgery

OBJECTIVE

The modified Glasgow Prognostic Score (mGPS) is an inflammation-based measure of malnutrition that reflects a state of cachexia in cancer patients. We evaluated mGPS as an index to predict surgical site infection (SSI) incidence in patients undergoing colorectal cancer surgery.

SUBJECTS AND METHODS

We retrospectively analyzed 351 patients who underwent colon cancer resection. Factors correlated with the incidence of SSIs were identified by logistic analysis and stepwise selection.

RESULTS

SSIs were observed in 32 patients, with an incidence of 9.1%. Univariate logistic analysis revealed mGPS (Score 2), laparotomy, resection of other organs, colostomy, excessive blood loss (>423 mL), long duration of surgery (>279 minutes), pulmonary dysfunction, prognostic nutritional index (PNI) ≤40, neutrophil lymphocyte ratio (NLR)(>4), and controlling nutritional status (CONUT) ≥2 to be associated with an increased incidence of SSIs. Multivariate analysis with variables selected by the stepwise procedure also revealed mGPS (Score 2) (Odds ratio (OR) =3.55, 95% Confidence interval (CI) 1.30-9.56; p=0.01), colostomy (OR=6.56, 95%CI 1.60-31.38; p=0.01), excessive blood loss (OR=3.20, 95%CI 1.23-8.42; p=0.02), and NLR (>4)(OR=3.24, 95%CI 1.31-8.17; p=0.01) to be independent risk factors.

CONCLUSION

mGPS is an independent risk factor for SSIs. Our results suggest that cachexia before surgery in patients with colorectal cancer might predict the incidence of SSIs.

Laparoscopic Surgery Reduces Risk of Postoperative Complications and Non Cancer-related Survival in Patients Over 80 Years Old With Colorectal Cancer

BACKGROUND

The short- and long-term results from several reports suggest that laparoscopic surgery (LAP) for elderly patients is expected to reduce the risk of complications due to its minimal invasiveness, However, little is known about the effect of LAP on long-term prognosis aside from cancer.

PATIENTS AND METHODS

Eighty-five cases over 80 years old with colorectal cancer whose primary lesions were resected consecutively were enrolled. Risk factors for complications were searched using categorized clinicopathological factors. The factors for death unrelated to cancer were analyzed in patients by excluding cancer-related death.

RESULTS

Incidence of all complications, those of Clavien-Dindo grade 2 or more, and surgical site infection were significantly lower in LAP-treated patients (p=0.0343, p=0.0015 and p=0.0015, respectively). By multivariate analysis, LAP (odds ratio=0.19, 95% confidence intervaI=0.05-0.75, p=0.0177) and no pulmonary dysfunction (odds ratio=0.24, 95% confidence intervaI=0.06-0.96, p=0.0441) were significantly associated with reduced risk of complications of Clavien-Dindo grade 2 or more. LAP, no pulmonary dysfunction and Eastern Cooperative Oncology Group performance status of 0 or 1 were also significantly associated with reduced risk for death from non cancer-related causes. Additionally, LAP was significantly associated with improved survival excluding cancer-related death in patients with pulmonary dysfunction (p=0.0020) or with poor performance status (p=0.0412).

CONCLUSION

These results suggest that fewer complications and non cancer-related deaths were achieved in very elderly patients with colorectal cancer when treated by LAP.

Expression of ATP-binding Cassette Transporter 11 (ABCC11) Protein in Colon Cancer

AIM

To investigate the clinical significance of ATP-binding cassette transporter 11 (ABCC11) protein expression in colon cancer.

MATERIALS AND METHODS

One hundred thirty nine patients with colon cancer resection between 2009 and 2011 were enrolled. The relationship with immunohistochemical ABCC11 staining and clinicopathological factors was retrospectively analyzed.

RESULTS

Median age was 70 years including 67 males and 72 females. The patients with Stage 0, 1, 2, 3a and 4 were 4, 20, 43, 35, 7 and 30, respectively. The patients with curability (Cur) A, B and C were 109, 11 and 19, respectively. Positive expression of ABCC11 was observed in 31 patients (22.3%). There were no significant differences regarding age, gender, location, serum tumor markers, T category, lymphatic invasion and stage in relation to ABCC11 protein expression. Cases with node metastasis and venous invasion as well as unresectable cases were significantly more often found negative for ABCC11 protein (p=0.0246, 0.0285 and 0.0422, respectively). Concerning the 3 year disease free survival (DFS) and the 5 year overall survival (OS) in Stage 2/3 and in Stage 3 with adjuvant chemotherapy, no significant differences were found. However, OS in ABCC11 negative cases was 81.1%, which was significantly lower compared to positive cases, where OS was 96.2%.

CONCLUSION

There was significant correlation with ABCC11 expression and lymph node metastasis, venous invasion and curability. The prognosis in ABCC11 negative cases was poor because of increased cases without curative resection.

Capecitabine Plus Bevacizumab as First-Line Therapy for Patients with Metastatic Colorectal Cancer and Poor Performance Status

BACKGROUND

The benefit of chemotherapy for patients with metastatic colorectal cancer has not been established.

METHODS

We retrospectively evaluated the effectiveness of chemotherapy with capecitabine and bevacizumab for patients with a performance status (PS) of 3.

RESULTS

Seven patients were included; median age was 82 years (range, 65-91 years). Response was not ascertained; however, the disease control rate was 83.3%. Median PFS and OS were 10.0 and 25.8 months, respectively. Hand-foot syndrome was the most common toxicity observed (3 patients; 42.9%). Grade 3 toxicity was observed in 1 patient with proteinuria and 1 with hypertension.

CONCLUSION

Chemotherapy using capecitabine and bevacizumab appeared to improve OFS and OS for patients with poor PS. However, care must be taken not to impose unnecessary burdens on patients with poor PS.

Subcuticular Suturing with Closed Suction Drainage for Wound Closure Following Stoma Reversal

Incisional surgical site infection (SSI) is a leading complication of stoma reversal procedures. This retrospective study was conducted to assess the incidence of incisional SSI and other wound complications when wound closure was achieved by subcuticular suturing and closed suction drainage following stoma reversal. We analyzed data from a total of 49 patients, all of whom had undergone insertion of a 10 Fr closed suction drainage tube in the fascia, following irrigation with approximately 300 mL of physiological saline. We then performed subcuticular suturing with 4-0 monofilament absorbable sutures. The median age of our patient population (34 men and 15 women) was 68 (range, 35-84) years. Six patients had an end stoma and 43 had a loop stoma. The wound category was 'contaminated' in 18 patients, while an incisional SSI was observed in one patient (2.0%). No wound disruptions, seromas, or drain infections were evident. Our data are reliable, but our study is limited in terms of general applicability; however, the low SSI rate indicates that the procedure is acceptable. Further research into this procedure will require a randomized trial design.

[Evaluation of Bridge to Surgery(BTS) after Stenting for Malignant Colorectal Stenosis]

OBJECTIVE

To evaluate the current status and postoperative course of nutritional management in bridge to surgery(BTS) after colorectal stenting for malignant colorectal stenosis.

SUBJECTS AND METHODS

The study included 242 colorectal cancer cases, 27 cases with malignant colorectal stenosis who underwent BTS group, 24 cases with malignant colorectal stenosis who fasted until the day of surgery and consumed drinking water and Elenthal®(no oral intake group), and 191 cases with non-stenotic colorectal cancer (diet group). The study items selected were nutritional management methods before colorectal cancer resection, nutritional assessment, surgical factors, and postoperative course.

RESULTS

The BTS, no oral intake, and diet groups were compared in 27, 0, and 191 patients, respectively. In contrast, the intake of Elenthal® was compared in 4, 20, and 5 patients and total parenteral nutrition in 3, 15, and 1 patients, respectively. There were no differences in nutritional sufficiency during hospitalization. The Onodera Nutritional Index(PNI)was significantly lower in the BTS and no oral intake groups than the diet group at the first outpatient visit before surgery. The PNI was significantly lower in the no oral intake group than in the diet group immediately before surgery. Blood loss was higher in the BTS and no oral intake groups than in the diet group, but there was no difference in operative time. The postoperative course was poorer in the no oral intake group than in the diet group. However, there was no difference between the diet and BTS groups.

CONCLUSION

In patients with obstructive colorectal cancer in whom BTS could be performed, the results suggest that preoperative nutritional management with a high sufficiency rate using the intestinal tract may lead to a postoperative course comparable to that in non-stenotic cases.

[A Case of Ascending Colon Cancer with Hepatic Metastases Showing Remarkable Efficacy of CapeOX plus Bevacizumab]

We report a case of ascending colon cancer with hepatic metastases that was treated by CapeOX plus bevacizumab with remarkable efficacy. A 40-year-old female patient presented with a medical history of surgery for resection of right breast cancer4 years ago, left-sided transverse colon 2 years ago, and right ovarian cancer 6 months ago. Follow-up computed tomography(CT)found wall thickening from the ascending colon to cecum. She was diagnosed with an ascending colon cancer by colonoscopy, and underwent right hemicolectomy. One month after the surgery, her serum marker carcinoembryonic antigen(CEA)and carbohydrate antigen 19-9(CA19-9)levels were high. She was diagnosed with unresectable multiple hepatic metastases by CT 2 months after the surgery. Her tumor was epidermal growth factor receptor(EGFR)- positive and wild-type for RAS; she received 4 courses of CapeOX plus bevacizumab. Thereafter, liver metastases were remarkably decreased in size, and she could undergo central bisegmentectomy. Pathology examination revealed no tumor and that the center of the tumor was changed to necrotic tissue and the surrounding area was changed to fibrous tissue and lymphocyte infiltration. The patient is disease-free since the last operation.

[A Case of Rectal Cancer Diagnosed Based on Brain Metastasis and Had a Long-Term Prognosis by Radical Resections]

The patient was a 57-year-old man who visited the department of neurosurgery for headache and lightheadedness. He was admitted with a diagnosis of brain tumor based on imaging findings. Severe brain dysfunction and mild ataxia were observed, and craniotomy tumor resection was performed 5 days after admission. He was diagnosed with brain metastasis of colorectal cancer based on histopathological examination and endoscopic findings, and was therefore referred to our department. No extracranial metastases were observed, laparoscopic-assisted low anterior resection was performed 1 month after the craniotomy. The final diagnosis was rectal cancer(Ra), pT3N0M1a(BRA), Stage Ⅳa. Three months after the craniotomy, subsequent MRI examination revealed a new metastatic lesion inferior to the tumor excision cavity, and gamma knife radiosurgery was performed. However, because an increasing tendency was noted, craniotomy was performed again 7 months after the first craniotomy. Following operative treatment, follow up has been performed without adjuvant chemotherapy or prophylactic irradiation, the patient has survived without recurrence at 34 months postoperatively. Here, we report a valuable rare case of solitary brain metastasis of colorectal cancer in which prognosis could be expected by radical resections.

[A Case of Lung Metastases from Rectal Cancer Treated for Quite Long with FOLFIRI plus Ramucirumab as a Late Line of Therapy]

We herein report a case of lung metastases from rectal cancer treated with FOLFIRI plus ramucirumab(Ram)therapy after salvage for a long time. A 44-year-old woman underwent low anterior resection for rectal cancer. Fifteen months after the surgery, mFOLFOX6 plus bevacizumab(BV)therapy was initiated for left obturator lymph node metastases. Although the target lesion shrunk, left lung metastasis was found 36 months after the surgery. Partial resection of the lung metastasis was performed, and carbon-ion radiotherapy for pelvic recurrence was administered. Following these treatments, mFOLFOX6 plus BV therapy was administered again for multiple lung metastases 42 months after the surgery. FOLFIRI plus BV therapy, TAS- 102 plus BV therapy, and regorafenib were then administered because of the disease progression. Although the best supportive care was provided after disease progression, FOLFIRI plus Ram therapy was initiated owing to the patient's wish. Although Grade 3 hematological toxicity was observed, severe digestive symptoms were not noted. Long-term administration(approximately 1 year, 21 courses)of the drugs was possible with withdrawal. The patient died due to disease progression 66 months after recurrence. We experienced a case in which FOLFIRI plus Ram therapy after salvage line could be administered for a quite long time. It has been suggested that anti-VEGF drugs with different targets may improve the prognosis even as a late line of therapy if it is tolerable.

[Experimental and clinical studies on tobramycin by intravenous drip infusion in the field of urology (author's transl)]

We carried out experimental and clinical studies on tobramycin (TOB), and the following results obtained. 1. Antibacterial activity Minimum inhibitory concentration (MIC) of TOB against clinically isolated 20 strains of P. aeruginosa, E. coli, K. pneumoniae, P. mirabilis, S. marcescens and S. faecalis was determined. Except of S. marcescens, the great part of those strains were under than 25 micrograms/ml. 2. Clinical effect TOB was treated 11 patients with chronic complicated urinary tract infection in the dose of 40-60 mg twice a day for 5 days by intravenous drip infusion. Clinical effect was excellent in 2 patients, good in 4 and poor in 5, efficacy rate was 55%. In bacteriological effects, eradication rate of causative 12 strains was 67%. Side effect was not observed for all cases.