Patient Satisfaction Survey on Portable Infusion Pumps for Colorectal Cancer Chemotherapy: Hard-Shelled or Soft-Shelled?

Purpose: Elastomeric infusion pumps are widely used in colorectal cancer chemotherapy. However, no studies to date have investigated patient preferences regarding different infusion pump types. Patients and Methods: Twenty patients with unresectable colorectal cancer undergoing chemotherapy were initially treated with a portable hard-shelled continuous infusion pump, followed by a soft-shelled continuous infusion pump. The respondents used a numerical rating scale (0-10) to rate their comfort when using each pump, their ease of carrying it, the pump size and shape, its weight, their ease of reading its memory, and their overall satisfaction with it. They were then asked to determine which pump they would ultimately prefer. Results: In terms of comfort, significantly higher user satisfaction was reported for the soft-shelled pump during the daytime and when going out (P < 0.001, P < 0.001, respectively). For pump portability, size, shape, and weight, the soft-shelled type also outperformed the hard-shelled one (P < 0.001, P=0.0011, P < 0.001, respectively). However, the hard-shelled pump scored significantly better in terms of ease of viewing memory (P < 0.001). Overall satisfaction was significantly higher for the soft-shelled pump than the hard-shelled type (P=0.0095). Finally, 13 patients (65%) indicated that they would prefer a soft-shelled pump for their next treatment, while only one patient (5%) preferred a hard-shelled alternative. A preference for soft-shelled pump was observed, particularly in female patients and those with a body mass index of < 22 kg/m2. Conclusion: The selection of portable elastomeric infusion pumps should consider the preferences of patients with colorectal cancer, as these devices have the potential to enhance their quality of life.

Identification and removal of unexpected proliferative off-target cells emerging after iPSC-derived pancreatic islet cell implantation.

Differentiation of pancreatic endocrine cells from human pluripotent stem cells (PSCs) has been thoroughly investigated for application in cell therapy against diabetes. In the context of induced pancreatic endocrine cell implantation, previous studies have reported graft enlargement resulting from off-target pancreatic lineage cells. However, there is currently no documented evidence of proliferative off-target cells beyond the pancreatic lineage in existing studies. Here, we show that the implantation of seven-stage induced PSC-derived pancreatic islet cells (s7-iPICs) leads to the emergence of unexpected off-target cells with proliferative capacity via in vivo maturation. These cells display characteristics of both mesenchymal stem cells (MSCs) and smooth muscle cells (SMCs), termed proliferative MSC- and SMC-like cells (PMSCs). The frequency of PMSC emergence was found to be high when 108 s7-iPICs were used. Given that clinical applications involve the use of a greater number of induced cells than 108, it is challenging to ensure the safety of clinical applications unless PMSCs are adequately addressed. Accordingly, we developed a detection system and removal methods for PMSCs. To detect PMSCs without implantation, we implemented a 4-wk-extended culture system and demonstrated that putative PMSCs could be reduced by compound treatment, particularly with the taxane docetaxel. When docetaxel-treated s7-iPICs were implanted, the PMSCs were no longer observed. This study provides useful insights into the identification and resolution of safety issues, which are particularly important in the field of cell-based medicine using PSCs.

The R436Q missense mutation in WWP1 disrupts autoinhibition of its E3 ubiquitin ligase activity, leading to self-degradation and loss of function.

Muscular dystrophy in the NH-413 chicken is caused by a missense mutation in the WWP1 gene. WWP1 is a HECT-type E3 ubiquitin ligase containing four tandem WW domains that interact with proline-rich peptide motifs of target proteins, and a short region connecting the second and third WW domains is crucial for the E3 ligase to maintain an autoinhibitory state. A mutation of the arginine in the WW2-WW3 linker to glutamine is thought to affect WWP1 function, but there is little information on this mutation to date. In this study, we generated a transgenic (Tg) mouse model expressing the WWP1 transgene with the R436Q mutation, which corresponds to the missense mutation found in the NH-413 chicken. Tg mice showed marked degradation of mutant WWP1 proteins in various tissues, particularly in striated muscle. Immunoprecipitation analysis using a WWP1-specific antibody demonstrated that the mutant WWP1 proteins lacked the C-terminal catalytic cysteine residue that is required for their binding to the E2-substrate complex during their degradation. In vitro analysis using the R436Q mutant of WWP1 lacking this catalytic cysteine residue showed no autodegradation, indicating that the loss-of-function degradation of this protein is caused by self-ubiquitination. Tg mice expressing R436Q WWP1 did not show stunted growth or premature death. Furthermore, histological analysis did not reveal any obvious changes. These observations suggested that the R436Q mutant WWP1 protein, which is released from autoinhibitory mode by its missense mutation, does not have abnormally activated enzyme function to substrates before its self-degradation and loss of enzyme function.

Causative alleles for chondrodysplastic dwarfism, factor XI deficiency, and factor XIII deficiency in the Kumamoto sub-breed of Japanese Brown cattle.

Japanese Brown cattle are the second most popular Wagyu breed, and the Kumamoto sub-breed shows better daily gain and carcass weight. One of the breeding objectives for this sub-breed is to reduce genetic defects. Chondrodysplastic dwarfism and factor VIII deficiency have been identified as genetic diseases in the Kumamoto sub-breed. Previously, we detected individuals in the Kumamoto sub-breed with causative alleles of genetic diseases identified in Japanese Black cattle. In the current study, 11 mutations responsible for genetic diseases in the Wagyu breeds were analyzed to evaluate the risk of genetic diseases in the Kumamoto sub-breed. Genotyping revealed the causative mutations of chondrodysplastic dwarfism, factor XI deficiency, and factor XIII deficiency and suggested the appearance of affected animals in this sub-breed. DNA testing for these diseases is needed to prevent economic loses in beef production using the Kumamoto sub-breed.

CDK8/19 inhibition plays an important role in pancreatic ß-cell induction from human iPSCs.

BACKGROUND: Transplantation of differentiated cells from human-induced pluripotent stem cells (hiPSCs) holds great promise for clinical treatments. Eliminating the risk factor of malignant cell transformation is essential for ensuring the safety of such cells. This study was aimed at assessing and mitigating mutagenicity that may arise during the cell culture process in the protocol of pancreatic islet cell (iPIC) differentiation from hiPSCs. METHODS: We evaluated the mutagenicity of differentiation factors used for hiPSC-derived pancreatic islet-like cells (iPICs). We employed Ames mutagenicity assay, flow cytometry analysis, immunostaining, time-resolved fluorescence resonance energy transfer-based (TR-FRET) cell-free dose-response assays, single-cell RNA-sequencing and in vivo efficacy study. RESULTS: We observed a mutagenic effect of activin receptor-like kinase 5 inhibitor II (ALK5iII). ALK5iII is a widely used ß-cell inducer but no other tested ALK5 inhibitors induced ß-cells. We obtained kinase inhibition profiles and found that only ALK5iII inhibited cyclin-dependent kinases 8 and 19 (CDK8/19) among all ALK5 inhibitors tested. Consistently, CDK8/19 inhibitors efficiently induced ß-cells in the absence of ALK5iII. A combination treatment with non-mutagenic ALK5 inhibitor SB431542 and CDK8/19 inhibitor senexin B afforded generation of iPICs with in vitro cellular composition and in vivo efficacy comparable to those observed with ALK5iII. CONCLUSION: Our findings suggest a new risk mitigation approach for cell therapy and advance our understanding of the ß-cell differentiation mechanism.

PMEL p.Leu18del dilutes coat color of Kumamoto sub-breed of Japanese Brown cattle.

BACKGROUND: Coat color is important for registration and maintenance of livestock. Standard coat color of Kumamoto sub-breed of Japanese Brown cattle is solid brown, but individuals with diluted coat color have been observed recently. In this study, we attempted to identify polymorphism(s) responsible for coat color dilution by whole genome analysis. RESULTS: One of the diluted cattle possessed 7302 exonic polymorphisms which could affect genes' function. Among them, 14 polymorphisms in 10 coat color-related genes were assumed to be specific for the diluted cattle. Subsequent genotyping with three diluted cattle and 74 standard cattle elucidated that PMEL p.Leu18del was the causative polymorphism for coat color dilution in this sub-breed. Individuals with del/del type of this polymorphism showed diluted coat color, but coat color of heterozygotes were intermediate with various dilution rates. CONCLUSIONS: Coat color dilution of Kumamoto sub-breed was caused by PMEL p.Leu18del. The causative del allele has been detected in several genetically distant cattle breeds, suggesting that PMEL p.Leu18del can be used as a DNA marker to control cattle coat color.

Characterization and reduction of non-endocrine cells accompanying islet-like endocrine cells differentiated from human iPSC.

The differentiation of pancreatic endocrine cells from human pluripotent stem cells has been thoroughly investigated for their application in cell therapy against diabetes. Although non-endocrine cells are inevitable contaminating by-products of the differentiation process, a comprehensive profile of such cells is lacking. Therefore, we characterized non-endocrine cells in iPSC-derived pancreatic islet cells (iPIC) using single-cell transcriptomic analysis. We found that non-endocrine cells consist of (1) heterogeneous proliferating cells, and (2) cells with not only pancreatic traits but also liver or intestinal traits marked by FGB or AGR2. Non-endocrine cells specifically expressed FGFR2, PLK1, and LDHB. We demonstrated that inhibition of pathways involving these genes selectively reduced the number of non-endocrine cells in the differentiation process. These findings provide useful insights into cell purification approaches and contribute to the improvement of the mass production of endocrine cells for stem cell-derived cell therapy for diabetes.

Leptin gene contributes to beef marbling standard, meat brightness, meat firmness, and beef fat standard of the Kumamoto sub-breed of Japanese Brown cattle.

The Kumamoto sub-breed of Japanese Brown cattle has unique characteristics, such as great growth rate, and their contribution as future breeding materials is expected. To develop a DNA marker for their breeding, we investigated the effects of Leptin gene, controlling energy homeostasis, on carcass traits of the Kumamoto sub-breed. Sequence comparison identified five single nucleotide polymorphisms (SNPs): four linked synonymous mutations and one nonsynonymous mutation. Statistical analysis revealed that c.239C > T (p.A80V) had significant effects on the traits related with quality grade: beef marbling standard (p = 0.0132), meat brightness (p = 0.0383), and meat firmness (p = 0.0115). The C allele showed favorable effects; these scores of the C/C cattle were significantly higher than those of the C/T cattle. On the other hand, the effect of c.399T > C was observed on meat firmness (p = 0.0172) and beef fat standards (BFS) (p = 0.0129). The C/C cattle showed higher values of these traits than the T/T cattle. Our data suggested that these SNPs in Leptin gene could be used as a DNA marker for breeding of the Kumamoto sub-breed.

Neuronal degeneration and cognitive impairment can be prevented via the normalization of mitochondrial dynamics.

Neuronal cells possess a certain degree of plasticity to recover from cell damage. When the stress levels are higher than their plasticity capabilities, neuronal degeneration is triggered. However, the factors correlated to the plasticity capabilities need to be investigated. In this study, we generated a novel mouse model that able to express in an inducible manner a dominant-negative form of MFN2, a mitochondrial fusion factor. We then compared the phenotype of the mice continuously expressing the mutated MFN2 with that of the mice only transiently expressing it. Remarkably, the phenotypes of the group transiently expressing mutant MFN2 could be divided into 3 types: equivalent to what was observed in the continuous expression group, intermediate between the continuous expression group and the control group, and equivalent to the control group. In particular, in the continuous expression group, we observed remarkable hyperactivity and marked cognitive impairments, which were not seen, or were very mild in the transient expression group. These results indicate that abnormal mitochondrial dynamics lead to stress, triggering neuron degeneration; therefore, the neurodegeneration progression can be prevented via the normalization of the mitochondrial dynamics. Since the availability of mouse models suitable for the reproduction of both neurodegeneration and recovery at least partially is very limited, our mouse model can be a useful tool to investigate neuronal plasticity mechanisms and neurodegeneration.

Tethered spinal cord related to caudal spinal dysraphism in a tailless Holstein calf.

A rare dysraphic caudal spinal anomaly, or caudal agenesis, comprising a tethered spinal cord, was found in a tailless Holstein calf that presented ataxia and paresis with analgesia of the hind limbs. The gently and slimly tapered conus medullaris was poorly formed between S2 and S3 which indicated that it was lying more caudally. The caudal end of the filum terminale adhered to the inner periosteum of the vertebral arch at S4, which is compatible with tethering of the spinal cord. The dysraphic changes from the secondary neurulation error and the longitudinal deranged cord morphology that may have been caused by the caudad traction due to tethering were confirmed. This represents the first bovine case with definitive morphological confirmation.

MC1R c.310G>- and c.871G > A determine the coat color of Kumamoto sub-breed of Japanese Brown cattle.

Coat color is one of the important factors characterizing breeds for domestic animals. Melanocortin 1 receptor (MC1R) is a representative responsible gene for this phenotype. Two single-nucleotide polymorphisms (SNPs) in bovine MC1R gene, c.296T > C and c.310G>-, have been well characterized, but these SNPs are not enough to explain cattle coat color. As far as we know, MC1R genotypes of Kumamoto sub-breed of Japanese Brown cattle have not been analyzed. In the current study, genotyping for c.296T > C and c.310G>- was performed to elucidate the role of MC1R in determining the coat color of this sub-breed. As a result, most animals were e/e genotype, suggesting the coat color of this sub-breed is derived from the e allele of MC1R gene. However, we found six animals with E/e genotype, which coat color would be black theoretically. Subsequently, sequence comparison was performed with these animals to identify other polymorphisms affecting coat color, elucidating that these animals possessed the A allele of c.871G > A commonly. c.871G > A was a non-synonymous mutation in the seventh transmembrane domain, suggesting alteration of the function and/or the structure of MC1R protein. Our data indicated that the A allele of c.871G > A might be a loss-of-function mutation.

Development of a novel murine heart failure model overexpressing human renin and angiotensinogen.

Renin is the rate-limiting enzyme of the renin-angiotensin system cascade, which drives the pathophysiological progression of heart failure. Species differences in the amino acid sequence of the catalytic domain of renin limit evaluations of the potency and efficacy of human renin inhibitors in animal models, and a high dose of inhibitors is usually needed to show its organ-protective effects in rodents. In the present study, we developed a novel murine heart failure model (triple-tg) to enable us to evaluate the cardioprotective effect of renin inhibitors at more relevant doses for humans, by cross-breeding calsequestrin transgenic (CSQ-tg) mice with human renin and human angiotensinogen double-transgenic mice. The triple-tg mice exhibited increased plasma renin activity, worsened cardiac hypertrophy, and higher mortality compared to CSQ-tg mice. Triple-tg mice treated with 10 mg·kg-1 of TAK-272 (imarikiren/SCO-272), an orally active direct renin inhibitor, exhibited improvements in heart failure phenotypes, such as cardiac hypertrophy and survival rate; however, a dose of 300 mg·kg-1 was required to improve symptoms in CSQ-tg mice. Our results suggest that this newly generated triple-tg heart failure model is useful to evaluate the cardioprotective effects of human renin inhibitors at clinically relevant doses, thereby minimizing the concerns of off-target effects related to much higher drug exposure than that achieved in clinical study.

Insulin-Deficient Diabetic Condition Upregulates the Insulin-Secreting Capacity of Human Induced Pluripotent Stem Cell-Derived Pancreatic Endocrine Progenitor Cells After Implantation in Mice.

The host environment is a crucial factor for considering the transplant of stem cell-derived immature pancreatic cells in patients with type 1 diabetes. Here, we investigated the effect of insulin (INS)-deficient diabetes on the fate of immature pancreatic endocrine cell grafts and the underlying mechanisms. Human induced pluripotent stem cell-derived pancreatic endocrine progenitor cells (EPCs), which contained a high proportion of chromogranin A+ NK6 homeobox 1+ cells and very few INS+ cells, were used. When the EPCs were implanted under the kidney capsule in immunodeficient mice, INS-deficient diabetes accelerated increase in plasma human C-peptide, a marker of graft-derived INS secretion. The acceleration was suppressed by INS infusion but not affected by partial attenuation of hyperglycemia by dapagliflozin, an INS-independent glucose-lowering agent. Immunohistochemical analyses indicated that the grafts from diabetic mice contained more endocrine cells including proliferative INS-producing cells compared with that from nondiabetic mice, despite no difference in whole graft mass between the two groups. These data suggest that INS-deficient diabetes upregulates the INS-secreting capacity of EPC grafts by increasing the number of endocrine cells including INS-producing cells without changing the graft mass. These findings provide useful insights into postoperative diabetic care for cell therapy using stem cell-derived pancreatic cells.

The non-synonymous mutation in bovine SPP1 gene influences carcass weight.

Meat quality in beef cattle is controlled by genetic factors. SPP1 (secreted phosphoprotein 1) gene, coding a multifunctional cytokine with diverse biological functions, is the candidate gene influencing carcass traits. In this study, we tried to discover DNA polymorphisms associated with beef quality in bovine SPP1 gene, so that two SNPs (single nucleotide polymorphisms) in the promoter region and one SNP in the CDS (coding sequence) region were identified. Although the formers were predicted to alter SPP1 expression, they did not show any effects on the traits. On the contrary, statistical analysis revealed that g.58675C > T, a non-synonymous mutation from threonine to methionine in the conservative region, had a significant effect on carcass weight. Carcass weight of the animals with C/T allele (473.9 ± 6.0 kg) was significantly heavier than that of the C/C homozygotes (459.2 ± 2.8 kg). Because SPP1 gene functions in skeletal muscle cells as a positive regulator, the non-synonymous mutation might influence muscle development and remodeling, resulting in increased carcass weight of the C/T animals. Our results indicate that the SNP can be applied as a DNA marker for the improvement of beef cattle.

Spectroscopic interferometer with a large length range by rotating diffraction grating.

A new method for spectroscopic interferometry using rotating diffraction grating was developed for industrial measurements. Two diffraction gratings increase the spectroscopic resolution, and the effective measuring range can be extended considerably. Instead of calibrating the wavelength, we used the Fabry-Perot Etalon (standard) to calibrate the system and determine the absolute position. The rotation diffraction gratings may also be used as a spectroscopic element over extensive ranges for low-cost and high-speed measurement. Our experiments indicate a length range of approximately 4.00 mm with repeatability of 0.17µm (0.0167%) for the narrow range and 3.84 µm (0.0955%) for the wide range.

Acquired Expression of Mutant Mitofusin 2 Causes Progressive Neurodegeneration and Abnormal Behavior.

Neurons have high plasticity in developmental and juvenile stages that decreases in adulthood. Mitochondrial dynamics are highly important in neurons to maintain normal function. To compare dependency on mitochondrial dynamics in juvenile and adult stages, we generated a mouse model capable of selective timing of the expression of a mutant of the mitochondrial fusion factor Mitofusin 2 (MFN2). Mutant expression in the juvenile stage had lethal effects. Contrastingly, abnormalities did not manifest until 150 d after mutant expression during adulthood. After this silent 150 d period, progressive neurodegeneration, abnormal behaviors, and learning and memory deficits similar to those seen in human neurodegenerative diseases were observed. This indicates that abnormal neuronal mitochondrial dynamics seriously affect survival during early life stages and can also significantly damage brain function after maturation. Our findings highlight the need to consider the timing of disease onset in mimicking human neurodegenerative diseases.SIGNIFICANCE STATEMENT To compare the dependency on mitochondrial dynamics in neurons in juvenile and adult stages, we generated a mouse model expressing a mutant of the mitochondrial fusion factor MFN2 in an arbitrary timing. Juvenile expression of the mutant showed acute and severe phenotypes and had lethal effects; however, post-adult expression induced delayed but progressive phenotypes resembling those found in human neurodegenerative diseases. Our results indicate that abnormal neuronal mitochondrial dynamics seriously affect survival during early life stages and can also significantly damage brain function after maturation. This strongly suggests that the timing of expression should be considered when establishing an animal model that closely resembles human neurodegenerative diseases.

Structure-Activity Relationship of Biakamide, Selective Growth Inhibitors under Nutrient-Starved Condition from Marine Sponge.

The tumor microenvironment is considered as one of the important targets for anticancer drug discovery. In particular, nutrient deficiency may be observed in tumor microenvironment; biakamides A-D (1-4) isolated from marine sponge Petrosaspongia sp. as growth inhibitors against cancer cells adapted to glucose-deprived conditions have potential as new drugs and tools for elucidating adaptation mechanisms to these conditions. In this paper, we investigated structure-activity relationship (SAR) of biakamide to create easily accessible analog and gain insights about participation of the substructures to growth-inhibitory activity toward development of anticancer drug. This work revealed that 14,15-dinor-biakamide C (5), which is easily accessible, has similar activity to natural biakamide C (3). In addition, detailed SAR study showed the terminal acyl chain is important for interacting with target molecule and amide part including thiazole ring has acceptability to convert structures without losing activity.

An administration of TAK-683 at a minimally effective dose for luteinizing hormone stimulation under the absence of the ovary induces luteinizing hormone surge in ovary-intact goats.

The present study aimed to evaluate hormonal responses and their association with the TAK-683 blood concentrations in goats administered TAK-683 at a low dose, which had been previously determined as the minimally effective dose for luteinizing hormone (LH) stimulation in ovariectomized goats. In Experiment 1, 5 µg of TAK-683 treatment had no significant stimulatory effect on LH secretion in ovariectomized Shiba goats (n = 4). In Experiment 2, cycling goats received the treatment of prostaglandin F2α and progesterone-releasing controlled internal drug releasing (CIDR) to induce the follicular phase, then they were treated with 5 µg of TAK-683 (hour 0) intravenously (n = 4, IV) or subcutaneously (n = 3, SC) or with vehicle intravenously (n = 4, control) at 12 h after CIDR removal. Blood samples were collected at 10-min (-2-6 h), 2-h (6-24 h), or 6-h (24-48 h) intervals. Ovarian ultrasonographic images were assessed daily to confirm ovulation after the treatment. A surge-like release of LH was immediately observed after injection in all animals in the IV (peak time: 4.2 ± 0.6 h, peak concentration: 73.3 ± 27.5 ng/ml) and SC (peak time: 4.6 ± 0.4 h, peak concentration: 62.6 ± 23.2 ng/ml) groups, but not in the control group. Ovulation was detected within 3 days after TAK-683 injection in all animals in the IV and SC groups, and the interval period from TAK-683 administration to ovulation in the IV group was significantly (P < 0.05) shorter than that of the control group. No significant changes were observed between the IV and SC groups in terms of luteal diameter and blood progesterone levels after ovulation. The present findings suggest that the involvement of one or more ovarian factor(s) is indispensable for a TAK-683-induced LH surge leading to ovulation in goats.

In Vivo Knockdown of Pathogenic Proteins via Specific and Nongenetic Inhibitor of Apoptosis Protein (IAP)-dependent Protein Erasers (SNIPERs).

Many diseases, especially cancers, result from aberrant or overexpression of pathogenic proteins. Specific inhibitors against these proteins have shown remarkable therapeutic effects, but these are limited mainly to enzymes. An alternative approach that may have utility in drug development relies on selective degradation of pathogenic proteins via small chimeric molecules linking an E3 ubiquitin ligase to the targeted protein for proteasomal degradation. To this end, we recently developed a protein knockdown system based on hybrid small molecule SNIPERs (Specific and Nongenetic IAP-dependent Protein Erasers) that recruit inhibitor of the apoptosis protein (IAP) ubiquitin ligases to specifically degrade targeted proteins. Here, we extend our previous study to show a proof of concept of the SNIPER technology in vivo By incorporating a high affinity IAP ligand, we developed a novel SNIPER against estrogen receptor α (ERα), SNIPER(ER)-87, that has a potent protein knockdown activity. The SNIPER(ER) reduced ERα levels in tumor xenografts and suppressed the growth of ERα-positive breast tumors in mice. Mechanistically, it preferentially recruits X-linked IAP (XIAP) rather than cellular IAP1, to degrade ERα via the ubiquitin-proteasome pathway. With this IAP ligand, potent SNIPERs against other pathogenic proteins, BCR-ABL, bromodomain-containing protein 4 (BRD4), and phosphodiesterase-4 (PDE4) could also be developed. These results indicate that forced ubiquitylation by SNIPERs is a useful method to achieve efficient protein knockdown with potential therapeutic activities and could also be applied to study the role of ubiquitylation in many cellular processes.

Biakamides A-D, Unique Polyketides from a Marine Sponge, Act as Selective Growth Inhibitors of Tumor Cells Adapted to Nutrient Starvation.

Biakamides A-D, novel unusually unique polyketides, were isolated from an Indonesian marine sponge (Petrosaspongia sp.) with a constructed bioassay using PANC-1 human pancreatic cancer cells. Through detailed analyses of the one- and two-dimensional NMR spectra of biakamides, planar chemical structures possessing a terminal thiazole, two N-methyl amides, a chloromethylene, and a substituted butyryl moiety were obtained. After elucidation of the configuration of the secondary alcohol moiety in biakamides A and B, the absolute stereostructures of the two secondary methyl groups in biakamides A-D were determined by the asymmetric total syntheses of all possible stereoisomers from the optically pure monoprotected 2,4-dimethyl-1,5-diol. Biakamides A-D showed selective antiproliferative activities against PANC-1 cells cultured under glucose-deficient conditions in a concentration-dependent manner. The primary mode of action of biakamides was found to be inhibition of complex I in the mitochondrial electron transport chain.