Quantum device designing (QDD) for future semiconductor engineering

In semiconductor device history, a trend is observed where narrowing and increasing the number of material layers improve device functionality, with diodes, transistors, thyristors, and superlattices following this trend. While superlattices promise unique functionality, they are not widely adopted due to a technology barrier, requiring advanced fabrication, such as molecular beam epitaxy and lattice-matched materials. Here, a method to design quantum devices using amorphous materials and physical vapor deposition is presented. It is shown that the multiplication gain M depends on the number of layers of the superlattice, N, as M = kN, with k as a factor indicating the efficiency of multiplication. This M is, however, a trade-off with transit time, which also depends on N. To demonstrate, photodetector devices are fabricated on Si, with the superlattice of Se and As₂Se₃, and characterized using current-voltage (I-V) and current-time (I-T) measurements. For superlattices with the total layer thicknesses of 200 nm and 2 μm, the results show that k_200nm = 0.916 and k_2μm = 0.384, respectively. The results confirm that the multiplication factor is related to the number of superlattice layers, showing the effectiveness of the design approach.

Catheter-associated bloodstream infection in patients with cancer: comparison of left- and right-sided insertions

BACKGROUND

There is limited research on the relationship between side of insertion of central venous catheter (CVAD) and bloodstream infection risk in patients with cancer.

AIM

To conduct an exploratory analysis of data from a randomized control trial (RCT) and data from a prospective cohort study to compare infection rates for right- and left-sided insertions.

METHODS

The study populations were patients aged >14 years with cancer from two tertiary hospitals in Brisbane, Australia. The primary endpoint was catheter-associated bloodstream infection (CABSI) adjudicated by blinded assessors. For the RCT, randomized intention-to-treat comparisons were conducted between left- and right-side allocated insertion for early (≤14 days) and late (>14 days) infection using Cox proportional hazards regression. The RCT data were also combined with cohort study data collected from one of the hospitals prior to the RCT and non-randomized comparisons conducted between left- and right-sided insertions.

FINDINGS

In 634 randomly allocated CVADs there were 141 CABSIs. Analysis showed strong evidence of right-side allocated insertions having an increased risk of early infection by 2.5 times (95% confidence interval (CI): 1.3-4.7); however, there was no evidence of increased risk for late infection (hazard ratio: 1.06; 95% CI: 0.71-1.59). Results from analysis of the RCT and cohort study data combined (2786 CVADs and 385 CABSIs) were similar.

CONCLUSION

There appears to be an increased risk of CABSI in patients with cancer for CVAD inserted into the right-side for around two weeks after line insertion. The mechanism underpinning the increased risk is unknown.

Kidney biopsy practice amongst Australasian nephrologists

BACKGROUND

Percutaneous kidney biopsy is the gold standard investigation for the diagnosis of kidney diseases. The associated risks of the procedure depend on the skill and experience of the proceduralist as well as the characteristics of the patient. The Kidney Health Australia - Caring for Australasians with Renal Impairment (KHA-CARI) guidelines on kidney biopsies, published in 2019, are the only published national kidney biopsy guidelines. As such, this study surveys current kidney biopsy practices in Australasia and examines how they align with the Australian guidelines, as well as international biopsy practice.

METHODS

A cross-sectional, multiple-choice questionnaire was developed examining precautions prior to kidney biopsy; rationalisation of medications prior to kidney biopsy; technical aspects of kidney biopsy; complications of kidney biopsy; and indications for kidney biopsy. This was distributed to all members of the Australian and New Zealand Society of Nephrology (ANZSN).

RESULTS

The response rate for this survey is approximately 21.4 % (182/850). Respondents found agreement (> 75.0 %) in only six out of the twelve questions (50.0 %) which assessed their practice against the KHA-CARI guidelines.

CONCLUSIONS

This is the first study of its kind where kidney biopsy practices are examined against a clinical guideline. Furthermore, responses showed that practices were incongruent with guidelines and that there was a lack of consensus on many issues.

The incidence of postoperative nausea and vomiting after caesarean section in patients with hyperemesis gravidarum: a retrospective cohort study

BACKGROUND

Postoperative nausea and vomiting is one of the most common anaesthetic complications of caesarean section. This study examined the association between hyperemesis gravidarum during pregnancy and nausea and vomiting after caesarean section.

METHODS

A single-centre, retrospective cohort study, using electronic databases of patients with and without hyperemesis gravidarum, undergoing caesarean section from 2015 to 2019. The incidence and severity of postoperative nausea and vomiting were established by a review of the documentation of administration of postoperative anti-emetics within the 24-h period after surgery, and examined using univariable, multivariable binary and ordered logistic regression models.

RESULTS

Data were compared for 76 patients with hyperemesis gravidarum and 315 patients without the condition. The incidence of postoperative nausea and vomiting in the hyperemesis group versus the non-hyperemesis group was 43.4% vs 29.6%, respectively. The odds of experiencing postoperative nausea and vomiting was 1.95 times higher in women with hyperemesis gravidarum than in those without (aOR 1.95, 95% CI 1.13 to 3.36, P=0.016). The odds of having more severe postoperative nausea and vomiting were greater in the hyperemesis gravidarum group (aOR 1.91, 95% CI 1.14 to 3.20, P=0.014).

CONCLUSION

Patients with hyperemesis gravidarum are more likely to develop nausea and vomiting after caesarean section, and this is likely to be of greater severity than in those without the condition. This finding should assist the effective provision of intra-operative and postoperative anti-emetics for patients with hyperemesis gravidarum undergoing caesarean section.

Alteration in faecal bile acids, gut microbial composition and diversity after laparoscopic sleeve gastrectomy

Background

Laparoscopic sleeve gastrectomy (LSG) is a well established treatment for severe obesity and type 2 diabetes. Although the gut microbiota is linked to the efficacy of LSG, the underlying mechanisms remain elusive. The effect of LSG for morbid obesity on the gut microbiota and bile acids was assessed here.

Methods

Severely obese subjects who were candidates for LSG were included and followed until 6 months after surgery. The composition and abundance of the microbiota and bile acids in faeces were assessed by 16S ribosomal RNA sequencing, quantitative PCR and liquid chromatography–mass spectrometry.

Results

In total, 28 patients with a mean(s.d.) BMI of 44·2(6·6) kg/m2 were enrolled. These patients had achieved excess weight loss of 53·2(19·0) per cent and showed improvement in metabolic diseases by 6 months after LSG, accompanied by an alteration in the faecal microbial community. The increase in α-diversity and abundance of specific taxa, such as Rikenellaceae and Christensenellaceae, was strongly associated with reduced faecal bile acid levels. These changes had a significant positive association with excess weight loss and metabolic alterations. However, the total number of faecal bacteria was lower in patients before (mean(s.d.) 10·26(0·36) log10 cells per g faeces) and after (10·39(0·29) log10 cells per g faeces) operation than in healthy subjects (10·83(0·27) log10 cells per g faeces).

Conclusion

LSG is associated with a reduction in faecal bile acids and greater abundance of specific bacterial taxa and α-diversity that may contribute to the metabolic changes.

Cytotoxicity effect of trastuzumab on canine peripheral blood mononuclear cells

BACKGROUND

Trastuzumab is an antibody drug used to treat human epidermal growth factor receptor 2 (HER2) overexpressing human metastatic breast cancer. Antibody-dependent cellular cytotoxicity (ADCC) is considered to be the major mechanism of cytotoxicity of the drug. However, its ability to induce an ADCC response in canine peripheral blood mononuclear cells (PBMCs) is not well established.

AIMS

We aimed to evaluate the ability of trastuzumab in enhancing the cytotoxicity of PBMCs against canine tumor cells.

METHODS

We used canine tumor cell lines isolated from metastatic mammary gland tumors (CHMm and CIPm) and thyroid adenocarcinoma (CTAC). The binding of trastuzumab to the cells was confirmed using flow cytometry analysis. Peripheral blood mononuclear cells obtained from healthy beagles and lymphokine-activated killer (LAK) cells, generated by interleukin-2 (IL-2) stimulation of PBMCs, were used as effector cells. Standard lactate dehydrogenase (LDH) release assay was used to measure the cytotoxicity of the LAK cells against tumor cell lines in the presence of trastuzumab.

RESULTS

Trastuzumab enhanced the cytotoxicity of PBMCs against CHMm. Moreover, LAK cells killed CHMm synergistically in the presence of trastuzumab. However, the presence of trastuzumab did not produce such a synergistic effect when LAK cells acted against CIPm and CTAC.

CONCLUSION

We confirmed the ability of trastuzumab to induce an ADCC response in canine PBMCs and determined its synergistic effect with LAK cells. Although the in vitro system in the present study did not show the induction of trastuzumab-mediated ADCC response against all canine tumor cell lines, the results of this study indicate the potential antitumor activity of trastuzumab in canines.

A prospective observational study of the change in systemic ionised calcium following 4% citrate locking of venous haemodialysis catheters in intensive care patients

Traditionally heparin has been the anticoagulant of choice for venous dialysis catheter locking. There is systemic leakage of heparin catheter locking solutions at the time of injection. Alternative agents, such as citrate, are increasingly being used. We are not aware of any data in the critical care literature on the effect of citrate locking of venous dialysis catheters on systemic ionised calcium (iCa²⁺). To assess the effect of 4% citrate locking of venous dialysis catheters on systemic iCa²⁺ in intensive care patients we performed a prospective observational study of 50 paired samples in 26 intensive care patients receiving 4% citrate dialysis catheter locking in an adult tertiary intensive care unit between May 2016 and December 2016. Arterial blood gas (ABG) analysis was performed prior to venous dialysis catheter locking and a baseline iCa²⁺ result obtained. The catheter was locked with 4% citrate solution. A further ABG was sampled between 30 and 120 seconds later and the iCa²⁺ results were compared. Patients were observed for clinical signs of hypocalcaemia. On average, there was little difference between the pre- and post-catheter locking iCa²⁺ (median pre-locking iCa²⁺ 1.19 mmol/l, mean change of +0.004 mmol/l, 95% confidence interval [CI] -0.004 to 0.013, P=0.34). There was no evidence this difference differed by length of catheter P=0.26) or site of catheter P=0.85) insertion, but there was some evidence that this differed by receipt of citrate dialysis circuit anticoagulation P=0.013). Patients who received citrate dialysis circuit anticoagulation had an increase in catheter locking iCa²⁺ by 0.017 mmol/l (95% CI 0.00 to 0.028). Locking of venous dialysis catheters with 4% citrate solution has no clinically significant effect on systemic iCa²⁺ in intensive care patients with indwelling venous dialysis catheters.

Introduction of a Mandatory Pre-Block Safety Checklist into a Regional Anaesthesia Block Room Service: A Quality Improvement Project

Wrong-side block is an uncommon yet potentially preventable complication of regional anaesthesia. One strategy for reducing the incidence of wrong-side block is to introduce an additional check into the pre-block workflow in the form of a block ‘time out’ or ‘stop before you block’. In the aftermath of a wrong-side block incident at our institution, the mandatory use of a pre-block safety checklist was successfully introduced into the workflow of the block room. Compliance with the checklist rose from 31% in the six-month pre-intervention phase to over 90% in the six-month post-intervention phase. This was achieved without any negative effect on block efficacy, theatre efficiency, complication rates or patient satisfaction. The high rate of checklist utilisation was associated with an increased rate of ultrasound video documentation. This suggests that there may be collateral benefit to using a pre-block safety checklist in addition to merely reducing the risk of wrong-side block.

Influence of Trendelenburg position and pneumoperitoneum treatment on gastroesophageal reflux in dogs

Gastroesophageal reflux is a latent factor that may cause esophagitis, esophageal stenosis, and aspiration pneumonia through the regurgitation of the gastric fluid contents. For laparoscopic surgery, posture-changing and pneumoperitoneum operations are conducted to develop the visual field. However, few studies have examined the influence of these operations on gastroesophageal reflux. In this experiment using 10 Beagles, 10 mL of contrast medium was administered into the stomach, and the dogs were placed in the Trendelenburg position with 10-degree tilting. Pneumoperitoneum treatment with carbon dioxide was performed, with an intraperitoneal pressure of 10 mmHg. The presence or absence of gastroesophageal reflux was evaluated using computed tomography (CT). In horizontal and Trendelenburg positions, there was no reflux of Contrast medium. However, reflux was observed in the Trendelenburg position under pneumoperitoneum (p<0.05). These results suggest that the risk of gastroesophageal reflux increases during laparoscopic surgery in the Trendelenburg position with 10-degree tilting under an intraperitoneal pressure of 10 mmHg.

Abstract P5-13-05: The relationship between the expression of FOXA1 and GATA3 and the efficacy of neoadjuvant endocrine therapy

Background.

The estrogen receptor (ER)/ GATA3/ Forkhead box A1 (FOXA1) network is necessary for the ERα functional signature specific to luminal type breast cancers. High expression of FOXA1 indicates a good prognosis in ER-positive breast cancer. However, little is known about the association between the expression of FOXA1 and GATA3, and the efficacy of neoadjuvant endocrine therapy (NAE). This study investigated their predictive potential for NAE and the changes of their expression after NAE.

Methods.

The expression of ER, progesterone receptor (PgR), Ki67, FOXA1, and GATA3 were analyzed by immunohistochemistry in 66 patients with hormone receptor-positive/ human epidermal growth factor receptor 2 (HER2)-negative breast cancer who had been treated with NAE between March 2003 and December 2012 at Kyushu University Hospital, National Kyushu Cancer Center, and Sagara Hospital. The association between the expression of biological marker and the efficacy of NAE, and their expression changes after NAE were evaluated.

Results.

The median age of the patients was 60 years (range, 30–84 years). Pre- and post-menopausal patients were 24 (36.4%) and 42 (63.6%). Endocrine agents that were administered are as follows: aromatase inhibitors (AIs) for 42 patients (63.6%), luteinizing hormone-releasing hormone (LHRH) agonist plus AI for 10 patients (15.2%), LHRH agonist plus tamoxifen for 13 patients (19.7%). NAE yielded a partial response (PR) in 21 patients (31.8%) and stable disease (SD) in 45 patients (68.2%). Breast conserving surgery was performed in 56 patients (84.8%) and mastectomy was performed in 10 patients (15.2%). Preoperative Endocrine Prognostic Index (PEPI) score was 0 in 10 patients (15.2%) and 1 or greater (score 1 ≤) in 56 patients (84.8%).

Pre-treatment FOXA1 expression was positively correlated with GATA3 (P = 0.0003) and PgR (P = 0.0138). Post-treatment Ki67 expression was significantly lower in tumors, which achieved PR compared with those with SD (P = 0.0007). The expression of PgR, Ki67, and FOXA1 was significantly lower in post-treatment tumors compared with those in pre-treatment samples (p &lt; 0.0001, p &lt; 0.0001 and p &lt; 0.0001, respectively). The expression of PgR, Ki67, and FOXA1 was significantly reduced in both tumors with PR and those with SD (PR: P = 0.0004, P &lt; 0.0001, and P = 0.0417, respectively; SD: P &lt; 0.0001, P = 0.0001, and P &lt; 0.0001, respectively). The expression of PgR, Ki67, and FOXA1 was significantly decreased in post-treatment tumors in both patients with the PEPI score 0 and those with score 1 ≤ (score 0: P = 0.0078, P = 0.0059, and P = 0.0098, respectively; score 1 ≤: P &lt; 0.0001, P &lt; 0.0001, and P = 0.0002, respectively). In tumors with PgR &gt; 20%, the expression of Ki67 and FOXA1 were significantly lower in post-treatment tumors (P &lt; 0.0001 and P &lt; 0.0001, respectively).

Conclusions.

FOXA1 expression correlated with PgR expression, and was reduced significantly after NAE. These results suggest that blocking the effect of estrogen might reduce FOXA1 expression.

Citation Format: Tanaka K, Tokunaga E, Inoue Y, Ueo H, Yamashita N, Sagara Y, Ohi Y, Taguchi K, Ohno S, Okano S, Kitao H, Oki E, Oda Y, Maehara Y. The relationship between the expression of FOXA1 and GATA3 and the efficacy of neoadjuvant endocrine therapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-13-05.

Impact of ex vivo administration of mesenchymal stem cells on the function of kidney grafts from cardiac death donors in rat

BACKGROUND

Mesenchymal stem cells (MSCs) have been applied to the treatment of various diseases, and MSC administration in marginal donor grafts may help avoid the ischemia-reperfusion injury associated with solid organ transplants. Given the reports of side effects after intravenous MSC administration, local MSC administration to the target organ might be a better approach. We administered adipose tissue-derived MSCs (AT-MSCs) ex vivo to donor rat kidneys obtained after cardiac death (CD).

METHODS

Using male Lewis rats (8-10 weeks), and a marginal transplant model of 1hr CD plus 1hr sub-normothermic ET-Kyoto solution preservation were conducted. AT-MSCs obtained from double-reporter (luciferase-LacZ) transgenic Lewis rats were injected either systemically (1.0 × 10(6) cells/0.5 mL) to bilaterally nephrectomized recipient rats that had received a marginal kidney graft (n = 6), or locally via the renal artery (500 μL ET-Kyoto solution containing the same number of AT-MSCs) to marginal kidney grafts, which were then preserved (1 hour; 22°C) before being transplanted into bilaterally nephrectomized recipient rats (n = 8). Serum was collected to assess the therapeutic effects of AT-MSC administration, and the recipients of rats surviving to Day 14 were separately evaluated histopathologically. Follow-up was by in vivo imaging and histological LacZ staining, and tumor formation was evaluated in MSC-injected rats at 3 months.

RESULTS

Systemic injection of MSC did not improve recipient survival. In vivo imaging showed MSCs trapped in the lung that later became undetectable. Ex vivo injection of MSCs did show a benefit without adverse effects. At Day 14 after RTx, 75% of the rats in the AT-MSC-injected group (MSC[+]) had survived, whereas 50% of the rats in the AT-MSC-non-injected group (MSC[-]) had died. Renal function in the MSC(+) group was improved compared with that in the MSC(-) group at Day 4. LacZ staining revealed AT-MSCs attached to the renal tubules at 24 hours after RTx that later became undetectable. Histopathologic examination showed little difference in fibrosis between the groups at Day 14. No teratomas or other abnormalities were seen at 3 months.

Phase II trial of preoperative S-1 plus cisplatin followed by surgery for initially unresectable locally advanced gastric cancer

BACKGROUND

The aim of this study was to evaluate the efficacy and feasibility of preoperative chemotherapy with S-1 plus cisplatin in patients with initially unresectable locally advanced gastric cancer.

METHODS

We enrolled patients with initially unresectable locally advanced gastric cancer because of severe lymph node metastases or invasion of adjacent structures. Preoperative chemotherapy consisted of S-1 at 80 mg/m(2) divided in two daily doses for 21 days and cisplatin at 60 mg/m(2) intravenously on day 8, repeated every 35 days. If a tumor decreased in size, patients received 1 or 2 more courses. Surgery involved radical resection with D2 lymphadenectomy.

RESULTS

Between December 2000 and December 2007, 27 patients were enrolled on the study. No CR was obtained, but PR was seen in 17 cases, and the response rate was 63.0%. Thirteen patients (48.1%) had R0 resections. There were no treatment related deaths. The median overall survival time (MST) and the 3-year overall survival (OS) of all patients were 31.4 months and 31.0%, respectively. Among the 13 patients who underwent curative resection, the median disease-free survival (DFS) and the 3-year DFS were 17.4 months and 23.1%, respectively. The MST and the 3-year OS were 50.1 months and 53.8%, respectively. The most common site of initial recurrence after the R0 resection was the para-aortic lymph nodes.

CONCLUSIONS

Preoperative S-1 plus cisplatin can be safely delivered to patients undergoing radical gastrectomy. This regimen is promising as neoadjuvant chemotherapy for resectable gastric cancer. For initially unresectable locally advanced gastric cancer, new trials using more effective regimens along with extended lymph node dissection are necessary.