Reproductive Characteristics and Suitability of Sterile dead end Knockout Nibe Croaker as a Recipient for Intraperitoneal Germ Cell Transplantation

The use of sterile recipients is crucial for efficiently producing donor-derived offspring through surrogate broodstock technology for practical aquaculture applications. Although knockout (KO) of the dead end (dnd) gene has been used in previous studies as a sterilization method, it has not been reported in marine fish. In this study, nibe croaker was utilized as a model for marine teleosts that produce small pelagic eggs, and the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system was utilized to produce dnd KO fish. The F1 generation, which carried a nonsense mutation in the dnd gene, was produced by mating founder individuals with wild-type counterparts. Subsequently, the F2 generation was produced by mating the resulting males and females. Among the F2 generations, 24.0% consisted of homozygous KO individuals. Histological analysis revealed that primordial germ cells (PGCs) were present in homozygous KO individuals at 10 days post-hatching (dph), similar to wild-type individuals. However, by 20 dph, PGCs were absent in KO individuals. Furthermore, no germ cells were observed in the gonads of both sexes of homozygous KO individuals at 6 months old, which is the typical maturity age for wild-type individuals of both sexes. In addition, when cryopreserved donor nibe croaker testicular cells were transplanted, only donor-derived offspring were successfully obtained through the spontaneous mating of homozygous KO recipient parents. Results indicate that dnd KO nibe croaker lacks germ cells and can serve as promising recipients, producing only donor-derived gametes as surrogate broodstock.

A patient with psittacosis from a pigeon: A reminder of the importance of detailed interviews and relative bradycardia

A 43-year-old man was brought to our hospital with fever. The initial diagnosis was bacterial pneumonia, and ampicillin/sulbactam was administered. However, defervescence was not achieved, and relative bradycardia was observed. Detailed history-taking revealed that the patient had been involved in caring for a wild pigeon before hospitalization. We changed the antimicrobial therapy to minocycline and the patient' s condition improved. Chlamydophila psittaci antibody was subsequently found to be increased four-fold, and psittacosis was diagnosed. This case acts a reminder to clinicians of the importance of both the history of exposure to any birds and vital signs, including relative bradycardia.

A case of fulminant Clostridium perfringens infection: Role of macroscopic examination of the serum and peripheral blood smears

A 69-year-old man was brought to our hospital by ambulance with a fever. The translucent pink color of the serum sample suggested severe hemolysis. His blood pressure dropped rapidly, and he later suffered a cardiopulmonary arrest and died approximately 30 h after arriving at our hospital. The day after the patient's death, Clostridium perfringens was detected in the blood culture taken at the time of hospital admission. When serum sample shows translucent pink to red color and bacilli from bacteria is identified in peripheral blood smear, Clostridium perfringens should be considered and appropriate medical treatment should be initiated immediately.

Suitability of hybrid mackerel (Scomber australasicus × S. japonicus) with germ cell-less sterile gonads as a recipient for transplantation of bluefin tuna germ cells

We aim to establish a small-bodied surrogate broodstock, such as mackerel, which produces functional bluefin tuna gametes by spermatogonial transplantation. When reproductively fertile fish are used as recipients, endogenous gametogenesis outcompetes donor-derived gametogenesis, and recipient fish predominantly produce their gametes. In this study, we assessed fertility of hybrid mackerel, Scomber australasicus × S. japonicus, and its suitability as a recipient for transplantation of bluefin tuna germ cells. Hybrid mackerel were produced by artificially inseminating S. australasicus eggs with S. japonicus spermatozoa. Cellular DNA content and PCR analyses revealed that F1 offspring were diploid carrying both paternal and maternal genomes. Surprisingly, histological observations found no germ cells in hybrid mackerel gonads at 120 days post-hatch (dph), although they were present in the gonad of 30- and 60-dph hybrid mackerel. The frequency of germ cell-less fish was 100% at 120-dph, 63.1% at 1-year-old, and 81.8% at 2-year-old. We also confirmed a lack of expression of germ cell marker (DEAD-box helicase 4, ddx4) in the germ cell-less gonads of hybrid mackerel. By contrast, expression of Sertoli cell marker (gonadal soma-derived growth factor, gsdf) and of Leydig cell marker (steroid 11-beta-hydroxlase, cyp11b1) were clearly detected in hybrid mackerel gonads. Together these results showed that most of the hybrid gonads were germ cell-less sterile, but still possessed supporting cells and steroidogenic cells, both of which are indispensable for nursing donor-derived germ cells. To determine whether hybrid gonads could attract and incorporate donor bluefin tuna germ cells, testicular cells labeled with PKH26 fluorescent dye were intraperitoneally transplanted. Fluorescence observation of hybrid recipients at 14 days post-transplantation revealed that donor cells had been incorporated into the recipient's gonads. This suggests that hybrid mackerel show significant promise for use as a recipient to produce bluefin tuna gametes.

Specific visualization of live type A spermatogonia of Pacific bluefin tuna using fluorescent dye-conjugated antibodies†

During our previous work toward establishing surrogate broodstock that can produce donor-derived gametes by germ cell transplantation, we found that only type A spermatogonia (ASGs) have the potency to colonize recipient gonads. Therefore, the ability to visualize ASGs specifically would allow the sequential analysis of donor cell behavior in the recipient gonads. Here we produced monoclonal antibodies that could recognize the cell surface antigens of ASGs in Pacific bluefin tuna (Thunnus orientalis), with the aim of visualizing live ASGs. We generated monoclonal antibodies by inoculating Pacific bluefin tuna testicular cells containing ASGs into mice and then screened them using cell-based enzyme-linked immunosorbent assay (ELISA), immunocytochemistry, flow cytometry (FCM), and immunohistochemistry, which resulted in the selection of two antibodies (Nos. 152 and 180) from a pool of 1152 antibodies. We directly labeled these antibodies with fluorescent dye, which allowed ASG-like cells to be visualized in a one-step procedure using immunocytochemistry. Molecular marker analyses against the FCM-sorted fluorescent cells confirmed that ASGs were highly enriched in the antibody-positive fraction. To evaluate the migratory capability of the ASGs, we transplanted visualized cells into the peritoneal cavity of nibe croaker (Nibea mitsukurii) larvae. This resulted in incorporated fluorescent cells labeled with antibody No. 152 being detected in the recipient gonads, suggesting that the visualized ASGs possessed migratory and incorporation capabilities. Thus, the donor germ cell visualization method that was developed in this study will facilitate and simplify Pacific bluefin tuna germ cell transplantation.

Density-tunable conjugation of cyclic RGD ligands with polyion complex vesicles for the neovascular imaging of orthotopic glioblastomas

Introduction of ligands into 100 nm scaled hollow capsules has great potential for diagnostic and therapeutic applications in drug delivery systems. Polyethylene glycol-conjugated (PEGylated) polyion complex vesicles (PICsomes) are promising hollow nano-capsules that can survive for long periods in the blood circulation and can be used to deliver water-soluble macromolecules to target tissues. In this study, cyclic RGD (cRGD) peptide, which is specifically recognized by αVβ3 and αvβ5 integrins that are expressed at high levels in the neovascular system, was conjugated onto the distal end of PEG strands on PICsomes for active neovascular targeting. Density-tunable cRGD-conjugation was achieved using PICsomes with definite fraction of end-functionalized PEG, to substitute 20, 40, and 100% of PEG distal end of the PICsomes to cRGD moieties. Compared with control-PICsomes without cRGD, cRGD-PICsomes exhibited increased uptake into human umbilical vein endothelial cells. Intravital confocal laser scanning microscopy revealed that the 40%-cRGD-PICsomes accumulated mainly in the tumor neovasculature and remained in the perivascular region even after 24 h. Furthermore, we prepared superparamagnetic iron oxide (SPIO)-loaded cRGD-PICsomes for magnetic resonance imaging (MRI) and successfully visualized the neovasculature in an orthotopic glioblastoma model, which suggests that SPIO-loaded cRGD-PICsomes might be useful as a MRI contrast reagent for imaging of the tumor microenvironment, including neovascular regions that overexpress αVβ3 integrins.

Rapid recovery from acute liver failure secondary to pancreatoduodenectomy-related non-alcoholic steatohepatitis

This report describes a case of liver failure secondary to pancreatoduodenectomy and rapid recovery following treatment. A 68-year-old woman with cancer on the ampulla of Vater underwent surgery for pancreatoduodenectomy. The patient developed liver failure 3 months postsurgically. She was hospitalized after presenting with jaundice, hypoalbuminemia and decreased serum zinc. Computed tomography (CT) of the abdomen showed a reduction in CT attenuation values postoperatively. We suspected fatty liver due to impaired absorption caused by pancreatoduodenectomy. We initiated treatment with branched-chain amino acids and a zinc formulation orally. Trace elements were administered intravenously. Two months after treatment, there was a noticeable improvement in CT findings. The patient's jaundice and hypoalbuminemia prompted a liver biopsy, which led to a diagnosis of non-alcoholic steatohepatitis.

Encapsulation versus aggregation of metal-organic cages controlled by guest size variation

The strength and mode of binding (inside vs outside) of bisanionic guest molecules to a cationic, self-assembled metal-organic cage depend on their size and the stoichiometry of the addition. Herein we show that the composition of the solid/liquid phase of a heterogeneous system can be kinetically controlled by the order of the addition of two different guest compounds.

Characterization of the portal signal during 24-h glucose delivery in unrestrained, conscious rats

To characterize the "portal signal" during physiological glucose delivery, liver glycogen was measured in unrestrained rats during portal (Po) and peripheral (Pe) constant-rate infusion, with minimal differences in hepatic glucose load (HGL) and portal insulin between the delivery routes. Hepatic blood flows were measured by Doppler flowmetry during open surgery. Changes in hepatic glucose, portal insulin, glucagon, lactate, and free fatty acid concentrations were generally similar in either delivery except for glucagon at 4 h. Hepatic glycogen, however, increased continuously in Po and was higher than Pe at 8 and 24 h, although it decreased to the level of Pe upon the removal of Po at 8 h. There was a near-linear relationship between hepatic glycogen and HGL in either delivery, with the slope being twice as high in Po and the intercepts converging to basal HGL. The hepatic response to Po did not alter upon 80% replacement by Pe. These results suggest that negative arterial-portal glucose gradients increase the rate of hepatic glycogen synthesis against the incremental HGL in an all-or-nothing mode.

Characterization of the portal signal in a nonsteady hyperglycemic state in conscious dogs

To characterize the "portal signal" in a nonsteady hyperglycemic state, the kinetic relationship between net hepatic glucose balance (NHGB) and either hepatic glucose load (HGL) or plasma insulin level was determined during glucose infusion using a catheter technique in 36 conscious dogs. Glucose was infused intraportally (Po group) and peripherally (Pe group) at 39, 56, and 83 micromol x kg(-1) x min(-1) over 2 h. There was a linear relationship between mean NHGB and either mean HGL or plasma insulin levels at each rate in either delivery (HGL: Po r = 0.99, Pe r = 0.95; insulin: Po r = 99, Pe r = 0.79). The threshold levels for net hepatic glucose uptake were 3.8 and 11.7 mmol/l for plasma glucose and 65 and 392 pmol/l for plasma insulin, respectively. The slope of the regression line against the abscissa was four times larger in portal than in peripheral delivery (HGL: Po 0.20 vs. Pe 0.05, P < 0.05; insulin: Po 0.19 vs. Pe 0.04, P < 0.05). These results suggest that the portal signal overrules the threshold of glucose for hepatic uptake by increasing hepatic extraction rate in a nonsteady hyperglycemic state.

Comparison of insulinotrophic actions of nateglinide with glibenclamide dissociated from absorption in conscious dogs

Nateglinide is more rapidly absorbed than glibenclamide. Therefore, the different absorption kinetics of both drugs were eliminated by intraportal administration in conscious fasted dogs. The plasma insulin profiles were compared under similar kinetic changes in plasma drug concentrations. After a priming dose of nateglinide (1 mg/kg. 5 min) or glibenclamide (40 microg/kg. 5 min), plasma drug concentrations reached a peak at 4 minutes (nateglinide, 80 +/- 5 micromol/L, n = 6 and glibenclamide, 263 +/- 60 nmol/L, n = 6) followed by a sustained level at approximately 30% of the peak concentration at 30 minutes. Nateglinide led to a rapid and constant reduction in arterial glucose of approximately 30% basal, while glibenclamide promoted a gradual decrease to approximately 50% basal at 120 minutes. An increase in plasma insulin level by nateglinide of 4 times basal (218 +/- 58 pmol/L v 47 +/- 3 pmol/L, P <.05, n = 6) occurred at 6 to 10 minutes followed by sustained release of 1.4 times basal (67 +/- 15 pmol/L, n = 6). The insulin surge was more than doubled (484 +/- 209 pmol/L, n = 6) under a euglycemic clamp. Insulin release by glibenclamide increased gradually reaching 10-fold basal (449 +/- 166 pmol/L, n = 6) at 60 minutes. This was not enhanced during a euglycemic clamp. Lowering the primed doses of nateglinide resulted in a diminished peak plasma insulin concentration. In contrast, glibenclamide caused only a slower increase, but eventually reaching a similar peak. By increasing the continuous infusion of nateglinide, the sustained insulin release was not altered. Glibenclamide, but not nateglinide, evoked prompt and sustained insulin release in the continuing presence of the other. These results are consistent with the concept that nateglinide produces a quick, but very short-lived, interaction with sulfonylurea (SU)-receptors on plasma membrane by free access of the drug from the cell exterior. In contrast, glibenclamide promotes a slow and longer interaction with the receptor by distribution of the drug into the cell inferior. We conclude, therefore, that not only the different kinetics of gastrointestinal (GI) absorption, but also the inherent difference in the interaction with beta cells is attributed to the different insulin release characteristics between nateglinide and glibenclamide in vivo.