Luminescent Heterobimetallic PtII-AuI Complexes Bearing N-Heterocyclic Carbenes (NHCs) as Potent Anticancer Agents

This study aims to probe into new series of heterobimetallic PtII-AuI complexes with a general formula of [Pt(p-MeC6H4)(dfppy)(μ-dppm)Au(NHC)]OTf, NHC = IPr, 2; IMes, 3; dfppy = 2-(2,4-difluorophenyl)pyridinate; dppm = 1,1-bis(diphenylphosphino)methane, which are the resultant of the reaction between [Pt(p-MeC6H4)(dfppy)(κ1-dppm)], 1, with [AuCl(NHC)], NHC = IPr, B; IMes, C, in the presence of [Ag(OTf)]. In the heterobimetallic complexes, the dppm ligand is settled between both metals as an unsymmetrical bridging ligand. Several techniques are employed to characterize the resulting compounds. Moreover, the photophysical properties of the complexes are investigated by means of UV-vis and photoluminescence spectroscopy. Furthermore, the experimental study is enriched by ab initio calculations (density functional theory (DFT) and time-dependent DFT (TD-DFT)) to assess the role of Pt and Au moieties in the observed optical properties. It is revealed that 1-3 is luminescent in the solid state and solution at different temperatures. In addition, the achieved results indicate the emissive properties of 1-3 are originated from a mixed 3IL/3MLCT excited state with major contribution of intraligand charge transfer (dfppy). A comparative study is conducted into the cytotoxic activities of starting materials and 1-3 against different human cancer cell lines such as the pancreas (MIA-PaCa2), breast (MDA-MB-231), cervix (HeLa), and noncancerous breast epithelial cell line (MCF-10A). The achieved results suggest the heterobimetallic PtII-AuI species as optimal compounds that signify the existence of cooperative and synergistic effects in their structures. The complex 3 is considered as the most cytotoxic compound with the maximum selectivity index in our screened complex series. Moreover, it is disclosed that 3 effectively causes cell death by inducing apoptosis in MIA-PaCa2 cells. Furthermore, the finding results by fluorescent cell microscopy manifest cytoplasmic staining of 3 rather than nucleus.

A Bio-Conjugated Chlorin-Based Metal-Organic Framework for Targeted Photodynamic Therapy of Triple Negative Breast and Pancreatic Cancers

The field of photodynamic therapy (PDT) has continued to show promise as a potential method for treating tumors. In this work a photosensitizer (PS) has been delivered to cancer cell lines for PDT by incorporation into the metal-organic framework (MOF) as an organic linker. By functionalizing the surface of MOF nanoparticles with maltotriose the PS can efficiently target cancer cells with preferential uptake into pancreatic and breast cancer cell lines. Effective targeting overcomes some current problems with PDT including long-term photosensitivity and tumor specificity. Developing a PS with optimal absorption and stability is one of the foremost challenges in PDT and the synthesis of a chlorin which is activated by long-wavelength light and is resistant to photo-bleaching is described. This chlorin-based MOF shows anti-cancer ability several times higher than that of porphyrin-based MOFs with little toxicity to normal cell lines and no dark toxicity.

Fluorinated Cycloplatinated(II) Complexes Bearing Bisphosphine Ligands as Potent Anticancer Agents

A family of cationic cycloplatinated(II) complexes [Pt(dfppy)(P^P)]Cl, dfppy = 2-(2,4-difluorophenyl)pyridine, incorporating bisphosphine ligands, P^P = bis(diphenylphosphino)methane (1, dppm), 1,2-bis(diphenylphosphino)ethane (2, dppe) and 1,2-bis(diphenylphosphino)benzene (3, dppbz), was prepared. The complexes were characterized by means of several analytical and spectroscopic methods. These complexes displayed acceptable stability in the biological environments which was confirmed by NMR, HR ESI-MS and UV-vis techniques. The antiproliferative properties of these complexes were evaluated by National Cancer Institute (NCI) at National Institutes of Health (NIH) against 60 different human tumor cell lines such as leukemia, melanoma, lung, colon, brain, ovary, breast, prostate and kidney. These complexes showed higher cytotoxicity than cisplatin against a wide variety of cancer cell lines such as K-562 (leukemia), HOP-92 (lung), HCT-116 (colon), OVCAR-8 (ovarian), PC-3 (prostate), MDA-MB-468 (breast), and melanoma cancer cell lines. Complex 3 as the most potent compound in this study furnished an excellent anti-proliferative activity compared to the cisplatin against Hela, SKOV3, and MCF-7 cancer cell lines. The main mode of the interaction of 1-3 with DNA was also determined using molecular docking studies.

A C^N Cycloplatinated(II) Fluoride Complex: Photophysical Studies and Csp3-F Bond Formation

This work reports the synthesis and characterization of a new C^N-based cycloplatinated(II) fluoride complex, [Pt(ppy)(PPh₃)F] (2; ppy = 2-phenylpyridinate), involving a Pt-F bond. The new complex is highly luminescent in the green area with a high quantum yield of 94.6% at 77 K. A comparison study of the heavier halogen derivatives reveals a descending emission quantum yield order of F > Cl > Br > I. Time-dependent density functional theory calculations ascribe the decreased emission efficiency to the decreasing trend of an intraligand (IL) transition from F to I, which accounts for the major radiative pathway. In addition, 2 is capable of the fluorinating alkyl halides, leading to C_sp³-F bond formation at room temperature.

Using a Faculty-Developed Documentary-Style Film to Communicate Authentic Chemistry Research to a High School Audience

Described is the creation, deployment, and evaluation of a video produced about the synthesis and applications of metal-organic frameworks (MOFs). The goal of this project was to gauge the impact of viewing the video on high school students' conceptions of authentic chemistry practices and applications. Additionally, comparisons were made between the use of the video and more traditional face-to-face presentations given by professional scientists. Observations, student surveys, and an interview with the high school chemistry teacher demonstrated the utility of such a video. Specifically, the students who viewed the video reported learning more about the nature of laboratory work in chemistry than other students who did not view the video. Students, regardless of whether they viewed the video or just received a presentation, reported growth in understandings of the applications of chemistry research and porous nanomaterial. Other research chemists are encouraged to consider ways that they could document on video the research that they are performing in order to introduce an untapped audience (high school students) to authentic chemistry research in a practically simple manner. During times of crisis, such as a pandemic, online videos could be a useful tool for high school chemistry teachers to use in collaboration with research faculty, particularly when schools are closed.

Maltotriose Conjugated Metal-Organic Frameworks for Selective Targeting and Photodynamic Therapy of Triple Negative Breast Cancer Cells and Tumor Associated Macrophages

Herein, we report a nano-MOF conjugated to maltotriose as a new DDS. MA-PCN-224-0.1Mn/0.9Zn showed its ability to target cancer and TAM. This novel MOF is an effective PDT agent and shows little dark toxicity, MA-PCN-224-0.1Mn/0.9Zn uptakes selectively into cancer cells. A well-suited size control methodology was used so that the nano-scaled MOFs may take advantage of the EPR effect. This development of a nano-scale MOF for PDT that is conjugated to a cancer targeting ligand represents a meaningful development for the use of MOFs as drug delivery systems.

Preparation and Applications of Metal-Organic Frameworks (MOFs): A Laboratory Activity and Demonstration for High School and/or Undergraduate Students

The chemistry of metal-organic frameworks (MOFs), a new class of emerging crystalline porous solids with three-dimensional (3D) networks composed of metals and multidentate organic molecules, was introduced by using three differently-shaped crystals. We reported new and mild MOF synthesis methods that are simple and devised to be performed in high school or primarily undergraduate school settings. MOF applications were demonstrated by use of our synthesized MOFs in the capture of iodine as a potentially hazardous molecule from solution and as a drug delivery system. These applications can be visually confirmed in minutes. Students can gain knowledge on advanced topics, such as drug delivery systems, through these easy-to-prepare MOFs. Furthermore, students can gain an understanding of powder X-ray analysis and ultraviolet-visible near-infrared spectroscopy. This laboratory experience is practical, including synthesis and application of MOFs. The entire experiment has also been recorded as an educational video posted on YouTube as a free public medium for students to watch and learn. In this article we first report the steps we took to synthesize and analyze the MOFs, followed by a description of a simple demonstration that we verified to effectively exhibit adsorption by MOFs. We conclude with a description of how the laboratory activity and demonstration was implemented in an undergraduate chemistry laboratory.

trans-Platinum(II) Thionate Complexes: Synthesis, Structural Characterization, and in vitro Biological Assessment as Potent Anticancer Agents

A series of Pt(II) complexes trans-[Pt(PPh2 allyl)2 (κ1 -S-SR)2 ], 1, PPh2 allyl=allyldiphenylphosphine, SR=pyridine-2-thiol (Spy, 1 a), 5-(trifluoromethyl)-pyridine-2-thiol (SpyCF3 -5, 1 b), pyrimidine-2-thiol (SpyN, 1 c), benzothiazole-2-thiol (Sbt, 1 d), benzimidazole-2-thiol (Sbi, 1 e), were synthesized. They were characterized by NMR, HR ESI-MS, and X-ray crystallography. Treatment of human cancer cell lines (A549, SKOV3, MCF-7) with these complexes resulted in promising antitumor effects in comparison with cisplatin. These compounds showed suitable selectivity between tumorigenic and non-tumorigenic (MCF-10 A) cell lines. Analyses of cell cycle progression and apoptosis were conducted for 1 a, the most cytotoxic compound, to screen dose/time response and to study the antiproliferative mechanism. An electrophoresis mobility shift assay was performed to assess the direct interaction of 1 a with DNA and the strong genotoxic ability was indicated through the comet assay method.

Micro-flow nanocatalysis: synergic effect of TfOH@SPIONs and micro-flow technology as an efficient and robust catalytic system for the synthesis of plasticizers

The combination of continuous flow technology with immobilizing of only 0.13 mol% of triflic acid (TfOH) on silica-encapsulated superparamagnetic iron oxide nanoparticles (SPIONs) under solvent-free conditions successfully provided a powerful, efficient, and eco-friendly route for the synthesis of plasticizers. The turnover frequency value in micro-flow conditions varied in the range of 948.7 to 7384.6 h^-1 compared to 403.8 to 3099 h^-1 for in-flask. This technique works efficiently, encouraging future applications of micro-flow nano-catalysis in green chemistry.

Thoracoscopic parasternal lymph node dissection for the staging of breast cancer

With the advent of advanced thoracoscopic techniques, new applications have been expanding their roles in thoracic surgery. The aim of this paper is to introduce our new thoracoscopic approach in performing parasternal lymph node dissection of advanced breast cancer for its staging. This technique does not need the removal of any costal cartilage which is usually done in the conventional classical technique after radical mastectomy. Thoracoscopic procedure, in which wide and complete parasternal lymph node dissection is done, is minimally invasive and easy to perform. Therefore, the thoracoscopic technique may be a suitable alternative to the conventional approach in the future.

Mediastinal liposarcoma appearing as a tumor arising in the esophageal wall

We report a case of mediastinal liposarcoma, a relatively uncommon neoplasm, in which the mass also appeared as a tumor arising in the esophageal wall. A 76-year-old man diagnosed with a posterior mediastinal mass had the tumor extirpated in local esophageal myectomy due to its unclear margin on the esophageal wall. The resected specimen was diagnosed as well-differentiated liposarcoma. Preoperative angiography showed the tumor received its blood supply from a branch of the left gastric artery, suggesting it arose in the lower esophageal segment close to the hiatus and extended to the mediastinum. Since this tumor's growth pattern differed completely from esophageal liposarcoma described in previous case reports, we concluded that it was mediastinal liposarcoma.

Enantioselective rhodium(I)-catalyzed hydrogenation of trifluoromethyl ketones

[figure: see text] The asymmetric hydrogenation of trifluoromethyl ketones to yield chiral alpha-trifluoromethyl alcohols with enantiomeric excesses up to 98% was achieved in the presence of chiral rhodium-(amidephosphine-phosphinite) complexes.

A comparison of the new preservation solution Celsior to Euro-Collins and University of Wisconsin solutions in lung reperfusion injury

BACKGROUND

The lung is particularly susceptible to reperfusion injury, both experimentally and clinically after transplantation. The extracellular-type preservation solution Celsior, which has been predominantly studied in cardiac preservation, has components designed to prevent cell swelling, free radical injury, energy depletion, and calcium overload. Using an isolated blood-perfused rat lung model, we investigated whether Celsior would decrease preservation injury and improve lung function after cold ischemic storage and reperfusion compared to Euro-Collins (EC) and University of Wisconsin (UW) solutions.

METHODS

Lewis rat lungs were isolated, flushed with the respective cold preservation solution, and then stored at 4 degrees C for 6 or 12 hr. After ischemic storage, the lung block was suspended from a force transducer, ventilated with 100% O2, and reperfused for 90 min with fresh blood via a cannula in the pulmonary artery. Lung compliance, alveolar-arterial oxygen difference, and outflow oxygen tension were all measured. The capillary filtration coefficient (Kf), a sensitive measure of changes in microvascular permeability, was determined.

RESULTS

For 6 hr of cold storage, lungs stored in Celsior had lower Kf values than those stored in EC, indicating decreased microvascular permeability. No other significant differences were noted between Celsior and EC or UW. For 12 hr of cold storage, Celsior provided increased oxygenation, decreased alveolar-arterial O2 differences, increased compliance, and decreased Kf values as compared to both EC and UW.

CONCLUSIONS

Celsior provides better lung preservation than EC or UW as demonstrated by increased oxygenation, decreased capillary permeability, and improved lung compliance, particularly at 12-hr storage times. These results are highly relevant, inasmuch as EC and UW are the most common clinically used lung preservation solutions. Further studies of Celsior in experimental and clinical lung transplantation, as well as in other solid organs, are indicated.

[Effect of unilateral superior cervical sympathetic ganglionectomy on the contralateral ganglion in rat]

The effect of unilateral superior cervical sympathetic ganglionectomy on the contralateral ganglion was investigated in Sprague-Dawley male rats employing histological and morphometrical procedures. Neuronal cells showed cell enlargement and no change in the nuclear size and the cell number. Neuronal hypertrophy was due to innervation by some fibers of the contralateral half of organs which had been innervated by the ipsilateral ganglion.

[Pathohistological changes of the superior cervical ganglion after 99.5% ethyl alcohol injection]

The authors attempted to clarify the histological changes of superior cervical ganglion (SCG) cells in chronological order. Adult rat SCGs were injected with ethyl alcohol and were examined under light microscopy after fixation and histological processes. All neurons showed the so-called coagulation necrosis. Inflammatory reactions characterized by cellular invasion were delayed in contrast to ethyl alcohol exposure from outside of the ganglion capsule.

Addition of aprotinin to organ preservation solutions decreases lung reperfusion injury

BACKGROUND

Organ preservation injury is associated with endothelial cell damage, destabilization of mitochondrial and cell membranes, and the release of proteolytic enzymes. In addition to its well-known clinical effect of reducing perioperative blood loss, aprotinin has antiproteolytic and membrane-stabilizing properties. We hypothesized that adding aprotinin to Euro-Collins (EC) and University of Wisconsin (UW) solutions would decrease preservation injury in cultured endothelial cells and a whole organ rat lung model.

METHODS

Bovine aortic endothelial cells were cultured and stored in the respective solution at 4 degrees C for 12 or 48 hours. Endothelial cell viability after storage was assessed by dimethylthiazole tetrazolium cytotoxicity assay. In the whole organ model, rat lungs were isolated, flushed with the respective solution, and stored at 4 degrees C for 6 or 12 hours. The lungs were ventilated with 100% O2 and reperfused with fresh blood. Alveolar-arterial O2 difference, O2 tension, capillary filtration coefficient, and compliance were determined.

RESULTS

Endothelial cell viability was optimized with the addition of aprotinin to EC and UW at a dose of 150 KIU/mL (0.02 mg/mL). In the isolated perfused lung model, after 6 hours of ischemic storage, aprotinin-enhanced (100 KIU/mL [0.014 mg/mL]) EC and UW decreased alveolar-arterial O2 difference, increased O2 tension, and decreased capillary filtration coefficient compared with EC and UW alone. After 12 hours of ischemic storage, aprotinin-enhanced EC and UW decreased alveolar-arterial O2 difference, increased O2 tension, decreased capillary filtration coefficient, and increased compliance compared with EC and UW alone.

CONCLUSIONS

The addition of aprotinin to EC and UW solutions increases endothelial cell viability in hypoxic cold storage conditions. In terms of whole organ function, aprotinin improves lung preservation as demonstrated by increased oxygenation and compliance, and decreased capillary permeability. This study is clinically applicable as there is already extensive experience with the use of aprotinin in heart and lung transplant recipients, in addition to its routine use in conventional cardiac operations.

Addition of a mast cell stabilizing compound to organ preservation solutions decreases lung reperfusion injury

OBJECTIVE

Research in lung transplant preservation has generally focused on free radicals and enzyme release from neutrophils, parenchymal cells, macrophages, and endothelium. The lung has a large resident population of mast cells that, when activated, release potent inflammatory mediators. We hypothesized that adding an inhibitor of mast cell degranulation, lodoxamide tromethamine (10 micromol/L), to Euro-Collins and University of Wisconsin preservation solutions, would decrease lung preservation injury.

METHODS

Rat lungs were isolated, flushed with the respective solution, and stored at 4 degrees C for 6 or 12 hours. The lungs were reperfused with fresh blood and ventilated with 100% oxygen. Alveolar-arterial oxygen difference, oxygen tension, capillary filtration coefficient, and compliance were determined.

RESULTS

After 6 hours of ischemic storage: lodoxamide tromethamine-enhanced Euro-Collins solution decreased alveolar-arterial oxygen difference from 539 to 457 (p = 0.004), increased oxygen tension from 119 to 205 mm Hg (p = 0.006), and decreased capillary filtration coefficient from 3.9 to 2.0 (p < 0.001); lodoxamide tromethamine-enhanced University of Wisconsin solution decreased alveolar-arterial oxygen difference from 546 to 317 (p < 0.001), increased oxygen tension from 166 to 335 mm Hg (p < 0.001), and decreased capillary filtration coefficient from 3.0 to 1.7 (p < 0.001). After 12 hours of ischemic storage, lodoxamide tromethamine-enhanced Euro-Collins solution decreased alveolar-arterial oxygen difference from 588 to 485 (p < 0.001), increased oxygen tension from 100 to 161 mm Hg (p = 0.012), decreased capillary filtration coefficient from 6.2 to 2.6 (p < 0.001), and increased compliance from 0.12 to 0.21 (p < 0.001); lodoxamide tromethamine-enhanced University of Wisconsin solution decreased alveolar-arterial oxygen difference from 478 to 322 (p < 0.001), increased oxygen tension from 214 to 335 mm Hg (p < 0.001), decreased capillary filtration constant from 4.2 to 2.0 (p < 0.001), and increased compliance from 0.20 to 0.25 (p < 0.001).

CONCLUSIONS

Addition of lodoxamide tromethamine to Euro-Collins or University of Wisconsin solution results in a marked decrease in lung reperfusion injury as demonstrated by increased oxygenation, decreased microvascular permeability, and increased compliance. These results are relevant as Euro-Collins and University of Wisconsin solutions are the most common clinically used lung preservation solutions. This study also highlights the deleterious role of resident mast cells in preservation injury.

Thoracoscopic treatment of esophagobronchial fistula with esophageal diverticulum

Thoracoscopic fistulectomy and diverticulectomy for esophagobronchial fistula with esophageal diverticulum were performed on a 49-year-old-woman. The neck of the diverticulum and the fistula were divided with endo-stapling technique. Intraoperative esophagoscopy was found to be useful for the definite localization and complete excision of the fistula and the diverticulum and the avoidance of stenosis of the esophagus. To avoid the recurrence of fistula, a pedicle of viable mediastinal pleura was interposed between esophageal and bronchial closures. Postoperative course was uneventful, and the complete relief of symptom was experienced for a period of 10 months after the operation. It is to be considered that the present thoracoscopic procedure with intraoperative esophagoscopy can be used as a standard operative procedure for esophagobronchial fistula with esophageal diverticulum.

Histopathological study on bone changes induced by recombinant granulocyte colony-stimulating factor in rats

Histopathological bone changes were examined in growing rats intravenously administered with high doses (100 and 1000 micrograms/kg/day) of recombinant human granulocyte colony-stimulating factor (rG-CSF) for 28 days. The changes were observed in the region where physiological bone resorption actively occurs in the growth phase, that is the trabeculae of metaphyseal spongy bone and the endosteum region of diaphyseal compact bone. Histologically, the changes involved accelerated osteoclastic bone resorption and osteogenesis due to intramembranous ossification. While osteoclastic bone resorption was observed in almost all lesions, about half of which were accompanied by osteogenesis. Bone changes which appeared after administration of rG-CSF were characterized by frequent occurrence at the site of highly osteoclastic activity and by initial osteoclastic resorption followed by osteogenesis due to intramembranous ossification. These results suggest that the main action of rG-CSF on bone may be an acceleration of osteoclastic bone resorption.

The age-related difference in bone changes in rats induced by recombinant human granulocyte colony-stimulating factor

We examined the bone changes in recombinant granulocyte colon-stimulating factor (rhG-CSF)-treated young and young adult rats in order to investigate the effect of age-related conditions of bone growth on the bone changes induced by rhG-CSF. Recombinant human G-CSF (100 and 1,000 micrograms/kg/day) was given to rats by daily intravenous injection for 28 days starting at the age of either 6 or 14 wk, and the hindlimb bones were evaluated histopathologically. In the young rats, bone lesions were observed in the 100- and 1,000-micrograms/k groups. In the young adult rats, lesions were found only in the 1,000-micrograms/kg group. The lesions involved accelerated osteoclastic bone resorption and osteogenesis due to intramembranous ossification and there was no age-related difference in these histopathological findings. However, both the incidence of bone involvement and the severity of lesions were greater in the young rats than in the dose-matched young adult rats. The results suggest that the higher dose of rhG-CSF may intrinsically induce bone lesions of a particular histopathological nature in rats regardless of their age, and the action of rhG-CSF on bone may be stronger in young growing rats than in young adults.

Thoracoscopic surgery combined with a supraclavicular approach for removing superior mediastinal tumor

This report introduces our new technique of thoracoscopic surgery combined with a supraclavicular approach for removing superior mediastinal tumor. A 68-year-old woman noticed a tumor palpable in the left supraclavicular fossa. The patient had no pain around the neck and shoulder. A radio-opaque shadow 6 cm in diameter was detected in her left apical lung field on chest roentgenogram. Chest CT and MRI showed that the tumor was located in the superior mediastinum, extending up to the thoracic inlet, and there was no invasion of the surroundings. At first, a thoracoscopic examination was performed to assess the possibility of the excision. After dissecting the tumor from the mediastinal tissue and the first costovertebrae as far as possible by thoracoscopic surgery, a supraclavicular approach was used to enter the thoracic cavity. Complete resection of the tumor was successfully performed by thoracoscopic surgery combined with a supraclavicular approach. The tumor was removed in a plastic bag through the supraclavicular defect. Postoperative histopathology revealed that the tumor was a benign neurogenic one. A satisfactory follow-up of 5 postoperative days was observed without any complications, and the patient was discharged. The procedure was safe, easy, and minimally invasive to perform. Moreover, the supraclavicular approach could be used to add trocar port if needed.

Rapid induction of more malignant tumors by various genotoxic carcinogens in transgenic mice harboring a human prototype c-Ha-ras gene than in control non-transgenic mice

In this study, we investigated the carcinogenic response of transgenic mice carrying the human prototype c-Ha-ras gene, namely Tg rasH2/CB6F1 mice, to various genotoxic carcinogens and compared it with that of control non-transgenic CB6F1 mice (non-Tg mice). The present studies were conducted as the first step in the evaluation of the Tg rasH2/CB6F1 mouse as a model for the rapid carcinogenicity testing system. Short-term (< or = 6 months) rapid carcinogenicity tests of various genotoxic carcinogens, 4-nitroquinoline-1-oxide, cyclophosphamide, N,N-diethylnitrosamine, N-methyl-N-nitrosourea, N-methyl-N'-nitro-N-nitrosoguanidine and methylazoxymethanol, revealed that Tg rasH2/CB6F1 mice are more susceptible to these genotoxic carcinogens than control non-Tg mice. Tg rasH2/CB6F1 mice developed tumors more rapidly compared with non-Tg mice. Malignant tumors were observed only in the carcinogen-treated Tg rasH2/CB6F1 mice, but not in non-Tg mice treated with the same carcinogens. Each carcinogen induced tumors in corresponding target tissues of the Tg rasH2/CB6F1 mice. Only a very few lung adenomas but no other tumors were seen as spontaneous tumors during the 6 months of carcinogenicity tests. These results demonstrate that more rapid onset and higher incidence of more malignant tumors can be expected with high probability after treatment with various genotoxic carcinogens in the Tg rasH2/CB6F1 mice than in control non-Tg mice. The Tg rasH2/CB6F1 mouse seems to be a promising candidate as an animal model for the development of a rapid carcinogenicity testing system.

Effects of a calcium channel blocker, nicardipine, on pressure-natriuresis in Dahl salt-sensitive rats

The effects of a calcium channel blocker, nicardipine, on pressure-natriuresis responses were studied in Dahl salt sensitive (DS) and resistant (DR) rats. Differences in the neural and endocrine background were minimized by renal denervation and by holding plasma vasopressin, aldosterone, corticosterone, and norepinephrine levels constant by intravenous infusion. The renal plasma flow (RPF) and glomerular filtration rate (GFR) of DS rats were disautoregulated in the low renal perfusion pressure range, while those of DR rats were autoregulated. Administration of nicardipine (0.3 microgram/kg/min) into the renal artery significantly increased RPF and GFR and abolished the autoregulation in both strains of rats. Nicardipine also sharpened the pressure-natriuresis responses in both strains without changes in fractional excretion of sodium. These findings suggest that nicardipine increased GFR and thereby improved the pressure-natriuresis responses of DS rats.

Contribution of prostaglandins to pressure natriuresis in Dahl salt-sensitive rats

To examine the role of prostaglandins on pressure natriuresis in Dahl salt-sensitive (DS) rat, the pressure-natriuresis relationships in DS and Dahl salt-resistant (DR) rats were characterized with or without indomethacin (2 mg/kg/h) by utilizing an in vivo renal perfusion study. When untreated, in the DS rat the pressure-natriuresis curve was blunted (P less than .05) and excretion of prostaglandin E2 (38 +/- 11 to 109 +/- 43 pg/min) was decreased in comparison to the DR rat. With indomethacin, the pressure-natriuresis curve in the DR rat was blunted, while no significant changes were observed in the DS rat. Plasma renin activity and concentration of atrial natriuretic peptide were not changed by the treatment of indomethacin in both strains. These results suggest that the decrease in renal prostaglandins, at least in prostaglandin E2, plays some role in blunting pressure natriuresis in DS rat.

Different effects of low and high doses of endothelin on haemodynamics and hormones in the normotensive conscious dog

The effects of low-dose endothelin on systemic haemodynamics and vasoactive hormones were examined in conscious dogs. In addition, we examined the effects of endothelin on pressor responses to noradrenaline and angiotensin II and the baroreflex regulation of heart rate in conscious dogs. Continuous infusion of 40 fmol/kg per min endothelin for 40 min induced a mild but significant reduction in mean arterial pressure from 89.1 +/- 1.7 to 82.7 +/- 2.0 mmHg (P less than 0.05), associated with decreases in total peripheral resistance 20 min later. A 400 fmol/kg per min dose of endothelin, on the other hand, induced a gradual elevation of mean arterial pressure from 89.2 +/- 2.3 to 96.8 +/- 2.0 mmHg (P less than 0.05), associated with increases in total peripheral resistance over 30 min. The 40 fmol/kg per min dose of endothelin infusion induced a significant reduction in plasma arginine vasopressin (AVP; P less than 0.05) and elevations of plasma atrial natriuretic peptide (ANP; P less than 0.05), plasma prostaglandin E2 (PGE2; P less than 0.05) and plasma 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha; P less than 0.05). The 400 fmol/kg per min dose produced elevations of AVP, ANP, PGE2 and 6-keto-PGF1 alpha (P less than 0.05). Pressor responses to noradrenaline and angiotensin II were significantly attenuated during continuous infusion of 40 fmol/kg per min endothelin, whereas 400 fmol/kg per min endothelin did not induce any significant changes compared with the control. Furthermore, baroreflex sensitivity was attenuated with 40 fmol/kg per min endothelin but did not show any significant changes at 400 fmol/kg per min.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitonin gene-related peptide modulates adrenal hormones in conscious dogs

The effects of a small dose (2 pmol/kg) of human calcitonin gene-related peptide I on plasma renin activity and hormones, including, aldosterone, ACTH, cortisol, AVP and ANH, were investigated in 14 conscious dogs. In addition, we studied the effects of calcitonin gene-related peptide on aldosterone secretion when it is stimulated by angiotensin II and ACTH. An intravenous bolus injection of 2 pmol/kg of calcitonin gene-related peptide raised plasma renin activity (by 216%, p less than 0.05), ACTH (by 85%, p less than 0.05), AVP (by 89%, p less than 0.05), and ANH (by 36%, p less than 0.05). Despite the elevation of plasma renin activity, aldosterone was decreased (by 52%, p less than 0.05). Cortisol did not change significantly. Infusion of 1 pmol.kg-1.min-1 of angiotensin II produced an elevation of aldosterone (by 186%, p less than 0.01), which was completely inhibited by pretreatment with an injection of 2 pmol/kg of calcitonin gene-related peptide. On the other hand, aldosterone secretion stimulated by ACTH was not altered significantly by pretreatment with an injection of 2 pmol/kg of calcitonin gene-related peptide. These results suggest that calcitonin gene-related peptide inhibits aldosterone secretion, especially when aldosterone is stimulated by angiotensin II. In addition, calcitonin gene-related peptide may be involved as an endocrine modulator in the physiological control of other several hormones closely related to the hemodynamics.

[Six-month intraperitoneal toxicity study of cefpirome sulfate in rats]

A six-month intraperitoneal chronic toxicity study of cefpirome sulfate (CPR) in rats as well as a two-month recovery study were carried out at dose levels of 51.2, 128, 320 and 800 mg/kg/day. The results are as follows. 1. CPR caused no remarkable clinical signs in the general condition of the animals. 2. Body weight gain was depressed in males and females given 800 mg/kg/day. Food consumption, however, was not afected at any dose level. Water consumption increased in males and females at dose of greater than or equal to 320 mg/kg/day. 3. Except an increase in urine volume in males at 800 mg/kg/day, no abnormalities in urinary parameters were found. 4. Frequent decreases in erythrocyte count, hematocrit and hemoglobin concentration were seen in males and females of the 800 mg/kg/day group. At this dose, certain males and females also showed an increase in the reticulocyte count. 5. The serum-biochemical examinations showed a very slight or slight decrease in total cholesterol in males and females given 320 mg/kg/day or more, and increases in uric acid and inorganic phosphorus concentration in some males and females given 800 mg/kg/day. 6. Very slight or slight increases in spleen weight in males and females at a dose of greater than or equal to 320 mg/kg/day, in thyroid weight in females at a dose of greater than or equal to 320 mg/kg/day and in kidney weight in males given 320 mg/kg/day or more as well as in females at 800 mg/kg/day were measured. Further, a decrease in thymus weight was seen in females of the 800 mg/kg/day group. 7. At autopsy, very slight or slight reddish browning of the thyroid was seen in males given 320 mg/kg/day or more and in females given 800 mg/kg/day.(ABSTRACT TRUNCATED AT 400 WORDS)

A case of pseudotumor cerebri following glucocorticoid therapy in which warfarin prevented recurrence

A patient with nephrotic syndrome developed pseudotumor cerebri following glucocorticoid therapy. Diagnosis of pseudotumor cerebri was based on satisfaction of four criteria proposed by Ahlskog and O'Neill. The symptoms of pseudotumor cerebri disappeared within 10 days. After a three-week interval of remission, relapse occurred. Glycerol and urokinase produced rapid resolution of the symptoms and warfarin prevented further recurrence of pseudotumor cerebri for one year. These results suggest that the pathogenesis of pseudotumor cerebri might be associated with the hypercoagulable state which was induced by glucocorticoid therapy and nephrotic syndrome.

Swelling of the Golgi apparatus and decrease of galactosyltransferase in polyamine-deficient bovine lymphocytes and epithelium of mouse small intestine

When bovine small lymphocytes stimulated by concanavalin A were treated with inhibitors (alpha-difluoromethylornithine (5 mM) and ethylglyoxal bis(guanylhydrazone) (100 microM)] of polyamine biosynthesis, swelling of the Golgi apparatus was observed. This was accompanied by decreases in the amount of the Golgi apparatus and of the specific activity of galactosyltransferase. Both spermidine and spermine, at physiological concentrations, stimulated galactosyltransferase activity 2-3-fold. When mice were treated with these inhibitors, the following changes were observed in the epithelial cells of small intestine: swelling of the Golgi apparatus; decrease in the amount of the Golgi apparatus; and decrease of galactosyltransferase activity.

[Emergency embolectomy in embolic occlusion of the middle cerebral artery]

The natural course of embolic occlusion of the middle cerebral artery (MCA) has many variations, which include the frequent appearance of hemorrhagic infarction. There are also fatal cases among which severe ischemic edema is found. There haven's been many cases reported of MCA embolectomy in the acute stage, and findings concerning them have been very complicated and hard to analyze. Nevertheless there certainly exist cases where remarkable improvement of neurological signs is shown soon after the procedure. Five cases of emergency embolectomy have been undergone in our hospital in the past 2 years. The results were better than results obtained in cases where embolectomy was not performed. Three male and two female cases are the objectives, whose average age was 61 +/- 6 years (ranging from 54 to 67 years). The left side of the MC was involved in three cases and the right in two, and all cases had past history of heart diseases which may have been the embolic source. Each case had undergone CT scan soon after admission to make sure not to be the other type of intracranial lesion. Cerebral angiography was performed next, to discover the site of the occlusion and the degree of collateral circulation. Emergency embolectomy was performed as soon as possible in every case. The functional outcome was estimated from the ADL three months later using the international fifth degree grading.

RESULTS

The period from onset to recanalization ranges between 4.5 to 11 hours (average 6.9 +/- 2.5 hours). Good MC recanalization was demonstrated in each case angiographically within a week after the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Histopathological studies of experimental marine toxin poisoning. II. The acute effects of maitotoxin on the stomach, heart and lymphoid tissues in mice and rats

Maitotoxin, one of the causative agents of ciguatera isolated from marine dinoflagellate, Gambierdiscus toxicus, induced severe pathomorphological changes in the stomach, heart and lymphoid tissues in mice and rats. Multiple erosions were observed in gastric mucosa accompanied by a marked increase in total calcium content 24 hr after i.p. injection of 200 or 400 ng/kg of maitotoxin. In contrast, there was no close temporal association between the accumulation of calcium and the morphological appearance of dead cells in the heart and thymus. Within 30 min of administration of 200 or 400 ng/kg of maitotoxin, a marked swelling was seen in the endothelial lining cells of blood capillaries between cardiac muscle fibers, followed by the cell death of the fibers. Injection of maitotoxin at a dose of 200 ng/kg or higher also resulted in necrosis of lymphocytes in the cortex of the thymus at 4 hr and in the medulla at 8 hr.

Relationship among activation of the Na+/H+ antiporter, ornithine decarboxylase induction, and DNA synthesis

The relationship among activation of the Na+/H+ antiporter, ornithine decarboxylase, and DNA synthesis was examined with bovine small lymphocytes stimulated by concanavalin A (Con A). The Na+/H+ antiport activity was activated immediately after addition of concanavalin A; the maximum was reached 1 h after Con A addition and the activation continued at least 6 h. With increasing concanavalin A concentrations, the activities of the Na+/H+ antiporter, ornithine decarboxylase, and DNA synthesis increased in a parallel manner. In the presence of HCO3- in the medium, the internal alkalinization of lymphocytes was not induced by Con A. Ornithine decarboxylase and DNA synthetic activities were not inhibited by 5-(N-ethyl-N-isopropyl) amiloride (EIPA), a specific inhibitor of the Na+/H+ antiporter. In contrast, in the absence of HCO3- in the medium, the internal pH was alkalinized approximately 0.06 pH units by Con A. EIPA did inhibit the alkalinization of the internal pH or DNA synthesis significantly. Ornithine decarboxylase activity was not inhibited by EIPA. These results indicate that the activation of a Na+/H+ antiporter is not a trigger for cell proliferation, but its activation is important probably through the maintenance of the internal pH optimum, especially in HCO3(-)-free medium.

[Acute spontaneous subdural hematoma associated with multiple aneurysms--a case report]

A case of acute spontaneous subdural hematoma associated with three aneurysms is reported. On March 12, 1984, a 47-year-old woman experienced the sudden onset of severe headache over the bilateral frontal region and vomiting. Three hours later, she was transferred to our hospital by ambulance car because of continuous headache and vomiting. She had no history of head trauma. She had been medicated hypertension for five years. On admission she suffered from headache and nausea. But there was no clinical sign in physical and neurological examinations. The meningeal irritation was not present, but lumbar puncture showed slightly pinky CSF with normal pressure. A plain computed tomographic scan showed a thin high density mass in the left temporal extra-axial region and the slight deviation of the midline structures to the right. Left carotid arteriogram showed an avascular region over the left cerebral convexity, an aneurysm of the left A2-A3 junction and a questionable aneurysm of the bifurcation of left middle cerebral artery. Right carotid arteriogram showed an aneurysm of the bifurcation of right middle cerebral artery. We diagnosed this case as an acute subdural hematoma by CT scan and arteriogram. We were perplexed preoperatively whether this bleeding was spontaneous or secondary to the rupture of aneurysm, and we could not deny the possibility of a ruptured aneurysm. On March 15, 1984, three days after onset, operation was performed. At operation, a small subdural hematoma was removed, and the underlying cortex was normal.(ABSTRACT TRUNCATED AT 250 WORDS)