Deuterium Magnetic Resonance Imaging Using Deuterated Water-Induced 2H-Tissue Labeling Allows Monitoring Cancer Treatment at Clinical Field Strength

PURPOSE

An accurate and noninvasive assessment of tumor response following treatment other than traditional anatomical imaging techniques is essential. Deuterium magnetic resonance spectroscopic (MRS) imaging has been demonstrated as an alternative for cancer metabolic imaging by high-field MRI using deuterium-labeled molecules. The study aim was to use 2H tissue labeling and deuterium MRI at clinical field strength for tumor visualization and assessment of three anticancer therapies in pancreatic cancer model mice.

EXPERIMENTAL DESIGN

MIA PaCa-2 pancreatic carcinoma and C26 colorectal carcinoma models of BALB/c-nu mice was prepared, and repeated deuterium MRI was performed during the first 10 days of free drinking of 30% D2O to track 2H distribution in tissues. 2H accumulation in the tumor after irradiation, bevacizumab administration, or gemcitabine administration was also measured in MIA PaCa-2-bearing mice. Confirmatory proton MRI, ex vivo metabolic hyperpolarization 13C-MRS, and histopathology were performed.

RESULTS

The mouse's whole-body distribution of 2H was visible 1 day after drinking, and the signal intensity increased daily. Although the tumor size did not change 1 and 3 days after irradiation, the amount of 2H decreased significantly. The 2H image intensity of the tumor also significantly decreased after the administration of bevacizumab or gemcitabine. Metabolic hyperpolarization 13C-MRS, proton MRI, and 2H-NMR spectroscopy confirmed the efficacy of the anticancer treatments.

CONCLUSIONS

Deuterium MRI at 1.5T proved feasible to track 2H distribution throughout mouse tissues during D2O administration and revealed a higher 2H accumulation in the tumor xenografts. This research demonstrated a promising successful method for preliminary assessment of radiotherapy and chemotherapy of cancer.

Therapeutic applications of local injection of hsa-miR-634 into canine spontaneous malignant melanoma tumors

Malignant melanoma (MM) is one of the most common tumors in both dogs and humans. As canine MM (CMM) and human MM (HMM) have similar clinical characteristics, CMM appears to be a good clinical model for HMM. We previously demonstrated that the introduction of a synthetic double-strand-microRNA-634 (miR-634) mimic triggered apoptotic cell death by directly targeting the genes associated with cytoprotective processes in various human cancer cell lines, including those of HMM. This study aimed to investigate the antitumor effects of the local administration of miR-634 on spontaneous CMMs to provide a basis for future applications of miR-634 formulations in HMM treatment. We found that miR-634 administration induced apoptosis in CMM cell lines in vitro via downregulation of Asct2, Nrf2, and survivin expression, similar to the mechanisms in HMM cell lines. Furthermore, intratumoral miR-634 administration induced antitumor effects in four of seven spontaneous CMM cases, with no adverse effects. Local administration of miR-634 to lung metastasis under ultrasound guidance induced tumor shrinkage. These results confirm the antitumor effect of the local administration of miR-634 in spontaneous CMM, a model for spontaneous HMM, thereby providing a novel treatment strategy for HMM.

Early Assessment of Radiation Treatment at Clinical Field Strength by D2O Administration and Deuterium MRI

PURPOSE/OBJECTIVE(S)

An accurate and non-invasive assessment of tumor response following treatment is essential. Traditional anatomical imaging techniques are insufficient before a significant morphological change can be observed. Metabolic imaging of molecular processes in the living body is also used. In recent years, deuterium magnetic resonance spectroscopic (MRS) imaging has been demonstrated as an alternative for cancer metabolic imaging by high-field (4-11T) MRI using deuterium-labeled molecules as a contrast agent. The study aim was to evaluate the feasibility of using deuterium MRI 1.5T for tumor visualization and early assessment of the efficacy of three anticancer treatment strategies (radiation and anticancer drugs) in pancreatic cancer model mice given heavy water (D2O) to induce deuterium (2H)-tissue labeling.

MATERIALS/METHODS

A MIA PaCa-2 pancreatic cancer model of six BALB/c-nu mice was prepared, and repeated deuterium MRI was performed during the first 10 days after starting free drinking of 30% D2O. We also evaluated 2H accumulation in the tumor after irradiation, bevacizumab administration, or gemcitabine administration of other 20 mice. Additional confirmatory proton MRI, ex vivo metabolic hyperpolarization 13C-MRS and histopathology were performed.

RESULTS

The mouse's whole-body distribution of 2H was visible 1 day after drinking, and the signal intensity increased daily. Although the tumor size did not change 1 and 3 days after irradiation, the amount of 2H in the tumor decreased significantly. The 2H image intensity of the tumor also significantly decreased after the administration of bevacizumab or gemcitabine. Metabolic hyperpolarization 13C-MRS, proton MRI and 2H-NMR spectroscopy confirmed the efficacy of the anticancer treatments.

CONCLUSION

Deuterium MRI at 1.5T proved feasibility to track 2H distribution throughout mouse tissues during D2O administration and revealed a higher 2H accumulation in the tumor xenografts. This research demonstrated a promising successful method for early assessment of radiotherapy and chemotherapy of pancreatic cancer.

The New Quantum Image by Dynamic Nuclear Polarized MRI for the Assessment of Cardiac Radioablation to the Cavotricuspid Isthmus

PURPOSE/OBJECTIVE(S)

Cardiac arrhythmias are usually treated with invasive, time consuming catheter ablation techniques. While recently stereotactic body radiotherapy (SBRT) is an emerging non-invasive treatment in the management of cardiac arrhythmias. To identify and assess the cardiac radioablation by MR examination, including diffusion-weighted MRI, dynamic Gd-enhanced MRI, MR spectroscopy, and T2-weighted MRI early after SBRT is very difficult. We have been developing the free radical imaging methods using Dynamic Nuclear Polarization (DNP)-MRI with nitroxyl radicals as a redox probe (e.g., 4-Methacryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempo methacrylate; TempoMC)). In this study, we examined the possibility of in vivo spatiotemporal visualization of SBRT for cardiac radioablation to the cavotricuspid isthmus (CTI) based on redox reaction by in vivo DNP-MRI.

MATERIALS/METHODS

All animal procedures were approved by institutional animal care and use committee and performed in full compliance with its guidelines. This study was conducted with two approaches. First, four mini pigs underwent electrophysiology assessment using electroanatomic mapping (EAM) before and 3 months after SBRT with single-fraction doses of 25 Gy. The target of CTI was defined by cardiologist. We defined the planning target volume (PTV): the internal margin (IM) + set up margin (SM) = SI 15 mm, AP 10mm, LR 10 mm were added to the target. Radiotherapy plans were created by the software used in daily clinical practice. Second, free radical imaging by low filed type of DNP-MRI was performed on the four mice before and after 25 Gy and 10 Gy irradiation to whole heart. ESR signal measurements were also performed.

RESULTS

A total dose of 25 Gy was successfully delivered to PTV in a single procedure in all mini pigs. EAM visualized the irradiated site and confirmed clockwise conduction block across the CTI. Although routine MRI could not detect the cardiac radiation injury clearly, the four mice of heart were well delineated on MRI and clearly visualized by DNP-MRI. DNP-MRI signal of TempoMC were decreased depending on prescribed irradiation dose.

CONCLUSION

These data demonstrated the safety and feasibility of SBRT for creating conduction block across the CTI in mini pigs. Although to identify and assess the irradiated site by routine MR examination was impossible, the free radical imaging methods using Dynamic Nuclear Polarization (DNP)-MRI with TempoMC could be a promising successful method for the assessment of cardiac radioablation. This new quantum image by DNP-MRI will open the possibility of treating cardiac arrhythmias by SBRT safety and noninvasively.

The effects of BPA-BNCT on normal bone: determination of the CBE value in mice‡

Boron neutron capture therapy (BNCT) with p-boronophenylalanine (BPA) is expected to have less effect on the decrease in normal bone strength than X-ray therapy. However, the compound biological effectiveness (CBE) value necessary to convert the boron neutron capture reaction (BNCR) dose into a bioequivalent X-ray dose has not been determined yet. The purpose of this study was to evaluate the influence of BNCT on normal bone in mice and to elucidate the CBE factor. We first searched the distribution of BPA in the normal bone of C3H/He mice and then measured the changes in bone strength after irradiation. The CBE value was determined when the decrease in bone strength was set as an index of the BNCT effect. The 10B concentrations in the tibia after subcutaneous injection of 125, 250 and 500 mg/kg BPA were measured by prompt gamma-ray spectroscopy and inductively coupled plasma (ICP)-atomic emission spectrometry. The 10B mapping in the tibia was examined by alpha-track autoradiography and laser ablation-ICP-mass spectrometry. The 10B concentration increased dose-dependently; moreover, the concentrations were maintained until 120 min after BPA administration. The administered 10B in the tibia was abundantly accumulated in the growth cartilage, trabecular bone and bone marrow. The bone strength was analyzed by a three-point bending test 12 weeks after irradiation. The bending strength of the tibia decreased dose-dependently after the irradiation of X-ray, neutron and BNCR. The CBE factor was obtained as 2.27 by comparing these dose-effect curves; the value determined in this study will enable an accurate dosimetry of normal bone.

Efficacy and adverse events of anthracycline and propranolol combination in five dogs with stage 3 hemangiosarcoma

Background

Canine hemangiosarcoma (HSA), which originates from endothelial cells, is one of the most common malignant neoplasms that frequently develop metastatic lesions. Although anthracycline-based HSA treatment strategies have been widely investigated, reliable therapy for dogs with clinically advanced-stage HSA (stage 3 HSA) has not been established yet. Recently, several studies have demonstrated that propranolol, a beta-adrenergic receptor antagonist, exhibits anti-tumor effects against tumors originating from vascular endothelial cells, indicating the possibility that propranolol is a candidate adjunctive agent for anthracycline-based therapy in dogs with stage 3 HSA. This study aimed to evaluate the clinical efficacy and adverse events (AEs) of anthracycline and propranolol combination in stage 3 HSA-affected dogs.

Case Description

We retrospectively investigated five dogs diagnosed with stage 3 HSA which were administered with both anthracycline and propranolol during the same period between January 2020 and August 2021. Clinical benefit was observed in four of five HSA dogs (one of complete response, one of partial response, and two of stable disease) with gross metastatic lesions by anthracycline and propranolol combination. Notably, some or all of the metastatic lesions were reduced in two cases. In all five dogs administered with anthracycline and propranolol combination, no serious and irreversible AEs were observed.

Conclusion

Our findings demonstrate the efficacy and safety of anthracycline and propranolol combination in stage 3 HSA-affected dogs. Further studies are needed to establish treatment protocols based on anthracycline and propranolol combination for dogs with advanced HSA.

Successful rescue treatment using chlorambucil for presumed recurrence of sinonasal lymphoma in a cat

Case summary

A 12-year-old male neutered domestic shorthair cat presented with a 2-week history of serous unilateral nasal discharge, swelling of the nasal bridge and sneezing. Whole-body CT revealed a mass filling the entire right nasal cavity with lysis of the cribriform plate. The cat was diagnosed with sinonasal large-cell lymphoma based on cytopathological analysis, with PCR-based lymphocyte clonality testing showing a monoclonal population with rearrangement of the immunoglobulin heavy chain gene. The cat received radiotherapy with a dose of 30 Gy in seven fractions given three times weekly, and then cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP)-based chemotherapy was initiated soon after completion of the radiotherapy schedule. Despite this treatment, CT performed 4 months after radiotherapy revealed enlargement of the lesion in the right nasal cavity consistent with presumed progression of the cat’s lymphoma. The cat then received rescue chemotherapy with chlorambucil, which markedly reduced the size of the disease burden in the nasal and frontal sinus without severe adverse effects. At the time of writing, the cat was receiving chlorambucil for 7 months without any clinical signs suggestive of tumour relapse.

Relevance and novel information

To our knowledge, this is the first case of feline sinonasal lymphoma with chlorambucil used as rescue chemotherapy. This case indicates that chemotherapy with chlorambucil may be a useful treatment option for cats with relapsing sinonasal lymphoma following radiotherapy and/or CHOP-based chemotherapy.

Computed tomography-based evaluation for normal adrenal gland size independent of body weight in dogs

Background: Computed tomography (CT) is useful for evaluating the anatomical position of the adrenal gland and the presence of adrenal tumor (AT) metastasis or vascular invasion from ATs. Aim: To determine a weight-independent reference for adrenal gland size in normal dogs using CT. Methods: The medical records database of Gifu University was searched for data collected from April 2010 to December 2015 for records of dogs that underwent abdominal CT. The CT images were retrospectively analyzed using a Digital Imaging and Communications in Medicine viewer. The ratios of the minor axes of the adrenal glands to the height of the spinal cavity were investigated. Results: In total, 939 dogs were included. The left and right adrenal minor axes showed a moderate positive correlation with body weight (right: r = 0.61, p < 0.05; left: r = 0.54, p < 0.05). The L4 spinal cavity height showed a strong positive correlation with body weight (r = 0.82, p < 0.05). The left and right adrenal minor axis/L4 spinal cavity ratio did not correlate with body weight (right: r = 0.02, p = 0.53; left: r = −0.082, p < 0.05). The 95% confidence intervals of the adrenal minor axis/L4 spinal cavity ratios were as follows: right: 0.5–1.3 and left: 0.5–1.4. Conclusion: These results indicate that the adrenal minor axis/L4 spinal cavity ratio can be used as an index of adrenal gland size that is not affected by body weight. Patients in whom the adrenal minor axis/L4 spinal cavity ratio exceeds the upper limit (right 1.3, left 1.4) may have adrenal swelling.

Combined Hypofractionated Radiotherapy and Chemotherapy Versus Hypofractionated Radiotherapy Alone for Cats with Localized Sinonasal Lymphoma

Despite considering hypofractionated radiotherapy (HRT) a useful treatment option for feline localized sinonasal lymphoma (stage I), the benefits of additional chemotherapy remain controversial. This retrospective cohort study evaluated the efficacy of the early initiation of chemotherapy in combination with HRT (HRTC) to prolong the progression-free survival (PFS) and overall survival (OS) in cats with localized sinonasal lymphoma compared with HRT alone. While 24 eligible cats received HRT alone (HRT group), 18 received HRTC (HRTC group). The total median administered dose was 35 Gy, with one fraction per week, for a median of five fractions. In the HRTC group, the chemotherapy protocol was cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP)-based and cyclophosphamide, vincristine, and prednisolone (COP)-based in 14 (78%) and 4 cats (22%), respectively. Cats in the HRTC group had significantly longer PFS (677 versus 104 days; P = .04) and OS (983 versus 263 days; P = .04) than those in the HRT group. Considering the poor outcome in the HRT group despite the cats having received rescue chemotherapy for progressive disease, the early initiation of additional chemotherapy along with HRT may be recommended for feline localized sinonasal lymphoma.

Outcome of Localized Bile Duct Carcinoma in Six Dogs Treated with Liver Lobectomy

The prognosis for bile duct carcinoma in dogs is generally believed to be poor. However, only a few studies have evaluated the postoperative outcomes in such cases. The objective of this case series was to describe the postoperative outcomes of localized intrahepatic bile duct carcinoma in dogs. The electronic medical records of 16 dogs with bile duct carcinoma were reviewed, and 6 dogs were included in the study. All cases were diagnosed as bile duct carcinoma using postoperative pathology, and five of them had already been diagnosed using preoperative core biopsy. The tumors in all of the dogs were confirmed as completely resected on histopathological examination. Two dogs received toceranib following the surgery. The median follow-up time was 693 days (range, 420-1386 days), with a median survival time of 894 days (range, 420-1386 days). Local recurrence or distant metastases were detected in two of the six dogs (33%) on 354 and 398 days following surgery, respectively. The median progression-free survival was 492 days (range, 354-1386 days). In conclusion, dogs with localized intrahepatic bile duct carcinoma had a good prognosis following complete surgical resection.

A frameshift variant in the EXT1 gene in a feline leukemia virus-negative cat with osteochondromatosis

Osteochondromatosis is a benign proliferative disorder characterized by cartilage-capped bony protuberances. In humans and most mammals, variants in the EXT1 or EXT2 gene are strongly correlated with the etiology of osteochondromatosis. However, in cats, osteochondromatosis has only been associated with feline leukemia virus infection. In this study, to explore other factors involved in the etiology of feline osteochondromatosis, we examined the EXT1 and EXT2 genes in a feline leukemia virus-negative cat with osteochondromatosis. Genetic analysis revealed a heterozygous single base pair duplication in exon 6 of the EXT1 gene (XM_023248762.2:c.1468dupC), leading to a premature stop codon in the EXT1 protein. Notably, this frameshift variant is recognized as one of the most common pathogenic variants in human osteochondromatosis. Our data suggest for the first time that genetic variants can have etiologic roles in osteochondromatosis in cats, as in humans and other animals.

Radiological Arterial Anatomy in Mature Microminipigs as a Pre-clinical Research Model in Interventional Radiology

PURPOSE

To define the radiological arterial anatomy in mature microminipigs as a pre-clinical research animal model in interventional radiology.

MATERIALS AND METHODS

Five female microminipigs (weighing 20.9 ± 2.9 kg) were used in this study. Under general anesthesia, computed tomography (CT) angiography was performed using a 16-slice CT scanner. CT was performed 12 s after initiation of an intravenous injection of 40 ml of nonionic contrast media at 3.0 ml/second using a power injector. The transverse CT angiography images were evaluated using a digital imaging and communication in medicine viewer, and the diameters of the following 41 arteries were measured.: ascending aorta, descending aorta, thoracoabdominal aorta, abdominal aorta, pulmonary artery trunk, both pulmonary, brachiocephalic artery, short common bicarotid, both common carotid artery, subclavian, bronchial, internal mammary, celiac, common hepatic, left lateral hepatic, middle hepatic, left hepatic, gastroduodenal, cranial duodenopancreatic, splenic, left gastric, cranial mesenteric, ileocolic , bilateral colic artery, caudal mesenteric, cranial rectal, renal, both external iliac arteries, internal iliac common trunk, and both internal iliac and femoral arteries.

RESULTS

The microminipigs' vascular anatomy was the same as domestic pig anatomy and similar to human anatomy. The diameter of the aorta (ascending to abdominal) was 17.1-7.0 mm, iliac and femoral arteries (internal iliac common trunk to femoral artery): 5.5-3.8 mm, pulmonary arteries: 9.3-14.7 mm, and major first aortic branches (e.g., celiac or brachiocephalic artery): 2.2-9.2 mm.

CONCLUSION

This study defined the microminipig arterial anatomy in the trunk.

Spatiotemporal imaging of redox status using in vivo dynamic nuclear polarization magnetic resonance imaging system for early monitoring of response to radiation treatment of tumor

In general, the effectiveness of radiation treatment is evaluated through the observation of morphological changes with computed tomography (CT) or magnetic resonance imaging (MRI) images after treatment. However, the evaluation of the treatment effects can be very time consuming, and thus can delay the verification of patient cases where treatment has not been fully effective. It is known that the treatment efficacy depends on redox modulation in tumor tissues, which is an indirect effect of oxidizing redox molecules such as hydroxyl radicals and of reactive oxygen species generated by radiation treatment. In vivo dynamic nuclear polarization-MRI (DNP-MRI) using carbamoyl-PROXYL (CmP) as a redox sensitive DNP probe enables the accurate monitoring of the anatomical distribution of free radicals based on interactions of electrons and nuclear spin, known as Overhauser effect. However, spatiotemporal response of the redox status in tumor tissues post-irradiation remains unknown. In this study, we demonstrate the usefulness of spatiotemporal redox status as an early imaging biomarker of tumor response after irradiation using in vivo DNP-MRI. Our results highlight that in vivo DNP-MRI/CmP allowed us to visualize the tumor redox status responses significantly faster and earlier compared to the verification of morphological changes observed with 1.5 T MRI and cancer metabolism (Warburg effect) obtained by hyperpolarized ¹³C pyruvate MRS. Our findings suggest that the early assessment of redox status alterations with in vivo DNP-MRI/CmP probe may provide very efficient information regarding the effectiveness of the subsequent radiation treatment.

Gastrointestinal stromal tumour lacking mutations in the KIT and PDGFRA genes in a cat

Molecular subtyping in gastrointestinal stromal tumours is a useful method for predicting the efficacy of treatment using tyrosine kinase inhibitors in humans. However, owing to the paucity of reports on mutational analyses, the association between genetic mutations and the therapeutic response to tyrosine kinase inhibitors remains unclear in feline gastrointestinal stromal tumours. In this report, we describe the case of a cat with a gastrointestinal stromal tumour which was unresponsive to tyrosine kinase inhibitors. A mutational analysis revealed that the cat lacked mutations in both the KIT and platelet-derived growth factor receptor-alpha (PDGFRA) genes. Our findings are consistent with the fact that KIT/PDGFRA wild-type gastrointestinal stromal tumours are less responsive to tyrosine kinase inhibitors in humans. This signifies the need for further evaluation and possibly individualised treatment for gastrointestinal stromal tumours in cats on the basis of mutational analyses.

Functional rice with tandemly repeated Cbl-b ubiquitin ligase inhibitory pentapeptide prevents denervation-induced muscle atrophy in vivo

Ubiquitin ligase Casitas B-lineage lymphoma-b (Cbl-b) play a critical role in nonloading-mediated skeletal muscle atrophy: Cbl-b ubiquitinates insulin receptor substrate-1 (IRS-1), leading to its degradation and a resulting loss in muscle mass. We reported that intramuscular injection of a pentapeptide, DGpYMP, which acts as a mimic of the phosphorylation site in IRS-1, significantly inhibited denervation-induced skeletal muscle loss. In order to explore the possibility of the prevention of muscle atrophy by diet therapy, we examined the effects of oral administration of transgenic rice containing Cblin (Cbl-b inhibitor) peptide (DGYMP) on denervation-induced muscle mass loss in frogs. We generated transgenic rice seeds in which 15 repeats of Cblin peptides with a WQ spacer were inserted into the rice storage protein glutelin. A diet of the transgenic rice seeds had significant inhibitory effects on denervation-induced atrophy of the leg skeletal muscles in frogs, compared with those receiving a diet of wild-type rice.

Three-dimensional conformal radiation therapy for canine aortic body tumour: 6 cases (2014-2019)

OBJECTIVE

To determine the feasibility of three-dimensional conformal radiation therapy for canine aortic body tumours.

MATERIALS AND METHODS

Medical records of dogs that had undergone three-dimensional conformal radiation therapy with presumptive diagnosis of aortic body tumour were reviewed for clinical characteristics, treatment modality and outcomes.

RESULTS

Eight dogs were diagnosed with aortic body tumour and were treated with three-dimensional conformal radiation therapy. One dog had proliferation of a mass in the right atrium during treatment and died of respiratory distress. Another dog did not undergo follow-up CT to evaluate the treatment response due to the increased blood urea nitrogen values. The remaining 6 dogs were included in the case series. Radiotherapy was performed using a median dose per fraction of 7 Gy (3.3-7.14 Gy), a median of seven divided doses (7-15) and a total median dose of 49 Gy (45-50 Gy). The median number of CT scans during the follow-up period was 5 (range: 3-8 times). CT revealed acute side effects in four dogs-grade 1 effects related to the lung (n = 4) and skin (n = 2). Self-limiting or asymptomatic late side effects (grade 1 lung-related effect) were observed in three dogs. After therapy, one dog demonstrated a complete response, another demonstrated a partial response and the disease remained stable in four animals. The median follow-up period was 514.5 (235-1219) days. After three-dimensional conformal radiation therapy, the aortic body tumour reduced gradually over time without regrowth in all these 6 dogs.

CLINICAL SIGNIFICANCE

In this small case series, aortic body tumours responded to three-dimensional conformal radiation therapy. Transient and self-limiting side effects of the treatments were common. Further controlled studies are required to prove the effectiveness and the safety of this intervention.

A retrospective analysis on the outcome of 18 dogs with malignant ovarian tumours

Little evidence is available regarding the prognosis of dogs with malignant ovarian tumours. The objective of this retrospective study was to describe the outcomes and determine the prognostic factors for dogs with malignant ovarian tumours following treatment, including surgery with or without adjuvant therapy. Eighteen dogs were studied, their median age was 12 years (range: 7-15 years), and their median body weight was 6.9 kg (range: 2.3-17.8 kg). Following histopathologic diagnoses revealed that granulosa cell tumour was the most common type (n = 9), followed by dysgerminoma (n = 5), and adenocarcinoma (n = 4). Eleven dogs had surgery alone. Seven dogs had surgery with adjuvant therapy, including chemotherapy and/or radiotherapy. The median survival time (ST) was 1009 days when only deaths owing to the ovarian tumours were considered, and predictors of median ST were T-category (≥ T3, 443 days vs ≤ T2, 1474 days; P = .002), presence of metastatic disease (present, 391 days vs absent, 1474 days; P < .001) and lymphovascular space invasion (present, 428 days vs absent, 1474 days; P = .003) in a univariate analysis. Median ST in dogs with granulosa cell tumour seemed longer than in dogs with dysgerminoma and adenocarcinoma, although the difference was statistically insignificant (1474 days vs 458 days, respectively; P = .10). Considering the good prognosis, aggressive treatment can be recommended for dogs with malignant ovarian tumours, especially early-stage cases. Despite metastasis being present at diagnosis, half of the dogs with metastasis survived for more than 1 year.

Dynamic contrast-enhanced computed tomography lymphangiography with intranodal injection of water-soluble iodine contrast media in microminipig: imaging protocol and feasibility

OBJECTIVES

To evaluate the optimal imaging protocol and the feasibility of intranodal dynamic contrast-enhanced computed tomography lymphangiography (DCCTL) in microminipigs.

METHODS

The Committee for Animal Research and Welfare provided university approval. Five female microminipigs underwent DCCTL after inguinal lymph node injection of 0.1 mL/kg of iodine contrast media at a rate of 0.3 mL/min with three different iodine concentrations: group 1, 75 mgI/mL; group 2, 150 mgI/mL; and group 3, 300 mgI/mL. The CT values of the venous angle, thoracic duct (TD), cisterna chyli, iliac lymphatic duct, and iliac lymph node were measured; increases in CT values pre- to post-contrast were assessed as the contrast-enhanced index (CEI). Multi-detector row CT (MDCT) and volume rendering images showing the highest CEI were qualitatively evaluated.

RESULTS

The CEI of all lymphatics peaked at 5-10 min. The mean CEI of TD at 10 min of group 2 (193.0 HU) and group 3 (201.5 HU) were significantly higher than that of group 1 (70.7 HU) (p = 0.024). The continuity and overall diagnostic acceptability of all lymphatic system components were better in group 3 (3.6 and 3.0, respectively) than group 1 (2.6 and 1.6) and group 2 (3.0 and 2.6) (p = 0.249 and 0.204).

CONCLUSIONS

The optimal imaging protocol for intranodal DCCTL could be dual-phase imaging at 5 and 10 min after the injection of 300 mgI/mL iodinated contrast media. DCCTL provided good images of lymphatics and is potentially feasible in clinical settings.

KEY POINTS

• Dynamic contrast-enhanced computed tomography lymphangiography with intranodal injection of water-soluble iodine contrast media showed the highest enhancement of all lymphatics at scan delays of 5 and 10 min. • The optimal iodine concentration for intranodal dynamic contrast-enhanced computed tomography lymphangiography might be 300 mgI/mL. • Intranodal dynamic contrast-enhanced computed tomography lymphangiography provided good images of all the lymphatic system components and is potentially feasible in clinical settings.

Nuclear Accumulation of β-Catenin in Cancer Stem Cell Radioresistance and Stemness in Human Colon Cancer

BACKGROUND/AIM

The aim of this study was to examine whether the Wnt/β-catenin signal activation is a cause of radioresistance in colon cancer by assessing the β-catenin localization and its correlation with cancer stem cells (CSCs).

MATERIALS AND METHODS

The nuclear levels of β-catenin, the hallmark of Wnt activation, were analyzed in HCT116 and SW480 cells by immunohistochemistry, before and after irradiation. Further, we assessed CSC populations by staining for aldehyde dehydrogenase-1 (ALDH1) and CD44.

RESULTS

β-catenin was localized predominantly in the nucleus and plasma membrane in SW480 and HCT116 cells, respectively. Compared to HCT116 cells, SW480 cells displayed higher Wnt activation. At 24 h after irradiation, most of the DSBs in SW480 cells were repaired, but were still present in HCT116 cells. Additionally, compared to HCT116 cells, a significantly higher proportion of SW480 cells were ALDH1- and CD44-positive.

CONCLUSION

Colon cancers with nuclear β-catenin accumulation demonstrated greater radio-resistance with a higher number of CSCs.

Survival analysis in dogs with urinary transitional cell carcinoma that underwent whole-body computed tomography at diagnosis

This retrospective study aimed to evaluate factors associated with survival and to compare characteristics between tumour localizations in dogs with urinary transitional cell carcinoma (TCC) that underwent whole-body computed tomography (CT) at diagnosis. Dogs with histologically confirmed TCC that received medical therapy between 2010 and 2017 were included; dogs that underwent surgery or radiotherapy for the primary tumour were excluded. According to the CT findings, primary tumour localization (classified into the Bladder, Urethra and Bladder and Urethra groups), prostate involvement, iliosacral lymphadenomegaly, sternal lymphadenomegaly and metastasis to the bone and lung were evaluated for survival analysis. CT at diagnosis revealed iliosacral lymphadenomegaly, sternal lymphadenomegaly, bone metastasis and lung metastasis in 47.7%, 18.5%, 24.6% and 35.4% of the 65 included dogs, respectively. The overall median survival time was 196 days. On multivariable analysis, TCC localization (hazard ratio [HR], 1.90; P = .037), bone metastasis (HR, 2.76; P = .013) and sternal lymphadenomegaly (HR, 3.56; P = .004) were significantly associated with survival. Compared to the Bladder group (n = 16), the Urethra group (n = 26) had higher metastasis rates to the bone (6.3% vs 42.3%; P = .045) and lung (6.3% vs 46.2%; P = .022). The survival time was shorter in the Urethra group than in the Bladder group (121.5 vs 420 days; P < .001), and it was similar only in female dogs (247 vs 420 days; P = .031). These findings suggest that whole-body CT could be valuable for predicting the prognosis in urinary TCC.

Hypofractionated radiotherapy in nine dogs with unresectable solitary lung adenocarcinoma

Although lung lobectomy is the most common treatment option for dogs with solitary lung tumors, surgery often cannot be performed at the time of diagnosis. In this retrospective, case series study, we described the effects of hypofractionated radiotherapy for tumor mass reduction in nine dogs with solitary lung adenocarcinoma that were later considered for surgical resection, and we assessed the tolerability of the radiation protocol. Tumors were deemed unresectable by the attending veterinarian. The dose prescription was 7.0-12.0 Gy/fraction in four to seven fractions, administered weekly for a total dose of 40-50 Gy. Treatment planning prioritized normal tissue dose constraints. The median interval between the last radiotherapy session and maximum tumor size reduction was 56 (range: 26-196) days, with six and three dogs exhibiting a partial response and stable disease, respectively. Although acute and late radiation-induced toxicity to the skin and/or lungs developed in all nine dogs, it was self-limiting or improved with short-term anti-inflammatory treatment. Tumor progression after initial size reduction was confirmed in three dogs at 62, 126, and 175 days, respectively, after the last radiotherapy session. Seven of the nine dogs underwent lobectomy a median of 68 days after radiotherapy when tumors were in partial response or stable disease or at the time of progression, and five received systemic chemotherapy concurrent with or after radiotherapy. These findings suggest that hypofractionated radiotherapy for canine solitary lung adenocarcinoma is useful when the tumor is large or when surgery cannot be performed immediately after diagnosis.

Endoscopic Ultrasound-Guided Fine-Needle Injection of Hydrogen Peroxide into the Pancreas: Feasibility and Tolerability Study Using a Survival Porcine Model

Hydrogen peroxide (H₂O₂) has been reported to be an effective radiation sensitizer for various cancers. A combination therapy comprising fine-needle injection (FNI) of H₂O₂ under endoscopic ultrasound (EUS) guidance and chemoradiation might improve treatment outcomes of pancreatic cancer; however, there have been no reports thus far. The aims of this study were to evaluate the feasibility and safety of EUS-FNI of H₂O₂ into the pancreas using a porcine survival model. EUS-FNI was performed in the pancreas of six pigs, which were randomly divided into three groups based on the solution injected: group 1, 2 mL of sodium hyaluronate (control); group 2, 0.5 mL of H₂O₂; group 3, 2 mL of H₂O₂. To evaluate any adverse events, blood tests and computed tomography (CT) were performed before and after FNI, as well as days 3 and 7 subsequently. The pigs were necropsied on day 7. Histologic evaluation was performed according to the criteria for experimental acute pancreatitis. EUS-FNI was successful in all pigs. CT immediately after FNI revealed gas formation in the FNI area in groups 2 and 3. No adverse events were revealed by blood tests and CT. Histologic evaluations revealed pancreatitis scores of 5 and 5 in group 1, 7 and 7 in group 2 and 14 and 15 in group 3. EUS-FNI of H₂O₂ into the pancreas is feasible; however, it could cause pancreatitis. FNI of H₂O₂ into only the pancreatic tumor might be ideal in minimizing possible adverse events.

Short-Term Administration of Single-Agent Toceranib in Six Cases of Inoperable Massive Canine Hepatocellular Carcinoma

Six dogs with massive hepatocellular carcinoma that was not amenable to surgery were treated by oral administration of single-agent toceranib at a dose of 2.0-3.0 mg/kg every other day for a minimum of 60 days. Partial response was achieved in three dogs, stable disease was achieved in one dog, and progressive disease occurred in two dogs, according to the canine Response Evaluation Criteria in Solid Tumors v1.0. Observed adverse events were mild to moderate in severity and reported in accordance with the Veterinary Cooperative Oncology Group's common terminology criteria for adverse events v1.1. Activities of alanine aminotransferase and alkaline phosphatase decreased in the cases that were sensitive to treatment with toceranib, whereas the activities remained high in resistant cases. Additionally, the level of phospho-vascular endothelial growth factor receptor 2 was found to be increased in a resistant case. Single-agent toceranib might prove to be an effective treatment for canine hepatocellular carcinoma pending further validation.

A case of prostate B-cell lymphoma recognized in the contents of an irreducible perineal hernia in a dog

We present a case of an intact 14-year-old male dog with a prostate B-cell lymphoma recognized in the contents of an irreducible perineal hernia. The enlarged prostate was replaced after reducing its size by partial excision, and the perineal hernia was repaired using the tunica vaginalis communis. However, the pelvic cavity was largely occupied by the replaced prostate, and urinary retention developed. The prostate was resected on the next day via abdominal median incision, and a bladder-urethra anastomosis was performed. Lymphoma has rarely been demonstrated to develop in the prostate, with the lesion comprising the hernia contents. The present study suggests the necessity of early treatment for perineal hernias and the possibility that lymphoma may be present in the hernia contents.

Combination Chlorambucil/Firocoxib or Chlorambucil/Prednisolone Treatment for Inflammatory Colorectal Polyps in Miniature Dachshunds

Inflammatory colorectal polyps (ICRP), which are more commonly recognized in miniature dachshunds, are thought to represent an immune-mediated disease. This retrospective case series describes six miniature dachshunds with refractory ICRP, who were treated with chlorambucil (CLB) combined with firocoxib or prednisolone. Improvement in clinical manifestations was seen in five of the six dogs by the end of the study period; four were treated with CLB/firocoxib and one with CLB/prednisolone. One dog had nonregenerative anemia after 23 mo of treatment with CLB, but whether there was a causative relationship was unclear. No severe adverse events were observed during treatment in the remaining five dogs. CLB in combination with firocoxib or prednisolone appears to be an effective alternative treatment for ICRP in dogs. Further studies are needed to confirm the effectiveness and long-term complications of CLB treatment for ICRP in dogs.

Computed Tomographic Evaluation of Presumptively Normal Canine Sternal Lymph Nodes

The sternal lymph nodes receive drainage from a wide variety of structures in the thoraco-abdominal region. Evaluation of these lymph nodes is essential, especially in cancer patients. Computed tomography (CT) can detect sternal lymph nodes more accurately than radiography or ultrasonography, and the criteria of the sternal lymphadenopathy are unknown. The purpose of this retrospective study was to describe the CT characteristics of the sternal lymph nodes in dogs considered unlikely to have lymphadenopathy. The ratio of the short axis dimension of the sternal lymph nodes to the thickness of the second sternebra was also investigated. At least one sternal lymph node was identified in each of the 152 dogs included in the study. The mean long axis and short axis dimensions were 0.700 cm and 0.368 cm, respectively. The mean ratio of the sternal lymph nodes to the second sternebrae was 0.457, and the 95% prediction interval ranged from 0.317 to 0.596 (almost a fixed value independent of body weight). These findings will be useful when evaluating sternal lymphadenopathy using CT.

Combination therapy with cisplatin, 5'-deoxy-5-fluorouridine (5'-DFUR) and mitomycin (MMC) in patients with inoperable, advanced gastric cancer

The optimal dose of cisplatin (CDDP) for combination chemotherapy for the treatment of inoperable, advanced gastric cancer has yet to be established. We therefore performed a randomized study to compare the therapeutic usefulness of two dose levels of cisplatin. 5'-deoxy-5-fluorouridine (5'-DFUR 1,400 mg/m(2)/d) was given orally on days 1 to 4 and 15 to 18. Mitomycin C (MMC, 5.75 mg/m(2)/d) was injected intravenously on day 5. In addition, 80 mg/m2/d of CDDP (regimen A) or 60 mg/m(2)/d of CDDP (regimen B) was given by 2-h intravenous drip infusion on day 5. This treatment cycle was repeated every four weeks. Fifty-six patients were enrolled. Clinical response was evaluated in 32 patients (regimen A, 16 patients; regimen B? 16 patients) with measurable lesions. The response rate was significantly higher with regimen A (9 PR/16, 56.3%) than with regimen B (3 PR/16, 18.9%) (p=0.028, chi(2) test). Median survival was slightly but not significantly longer with regimen A (7.4 months) than with regimen B (6.3 months). Drug toxicity included myelosuppression and gastrointestinal symptoms, but there were no serious adverse reactions or differences in safety between the treatment regimens. Regimen A was associated with a high response rate and low toxicity. The optimal dose of CDDP in combination with 5'-DFUR and MMC for the treatment of advanced gastric cancer is regarded to be 80 mg/m(2).

Search for the Θ+ pentaquark via the π(-)p→K(-)X reaction at 1.92 GeV/c

The Θ(+) pentaquark baryon was searched for via the π(-)p→K(-)X reaction with a missing mass resolution of 1.4 MeV/c(2) (FWHM) at the Japan Proton Accelerator Research Complex (J-PARC). π(-) meson beams were incident on the liquid hydrogen target with a beam momentum of 1.92 GeV/c. No peak structure corresponding to the Θ(+) mass was observed. The upper limit of the production cross section averaged over the scattering angle of 2° to 15° in the laboratory frame is obtained to be 0.26 μb/sr in the mass region of 1.51-1.55 GeV/c(2). The upper limit of the Θ(+) decay width is obtained to be 0.72 and 3.1 MeV for J(Θ)(P)=1/2(+) and J(Θ)(P)=1/2(-), respectively, using the effective Lagrangian approach.

Experimental diabetes attenuates calcium mobilization and proliferative response in splenic lymphocytes from mice

The present study was conducted to investigate the effects of the diabetic condition on cytosolic free Ca(2+) concentration, [Ca(2+)](i), and the proliferation of splenic lymphocytes from mice. Diabetes was induced in mice by intraperitoneal injection of alloxan. [Ca(2+)](i) and the proliferation ex vivo of splenic lymphocytes isolated from mice were examined using fura-2 and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, respectively. Diabetes caused a significant increase in resting [Ca(2+)](i) and significantly reduced the ability of concanavalin A (Con A; a T-lymphocyte-selective mitogen) to increase [Ca(2+)](i), but not that of lipopolysaccharide (LPS; a B-lymphocyte-selective mitogen). In addition, diabetes significantly reduced Con A-stimulated but not LPS-stimulated lymphocyte proliferation. Verapamil (an L-type Ca(2+) channel blocker) inhibited Con A-induced increases in [Ca(2+)](i) and proliferation in lymphocytes from control and diabetic mice to a similar extent, respectively. These results suggest that diabetes attenuates Con A-stimulated T-lymphocyte proliferation by decreasing [Ca(2+)](i) via reduction of Ca(2+) entry through L-type Ca(2+) channels.

Networking possibilities for waste recycling in Miyagi prefecture, Japan

Successful case studies for waste recycling in Japan have not been evaluated. The evaluation of economic efficiency and environmental effects were lacking at the time the actual network was established. A waste/resource input/output (I/O) coincidence retrieval system called ZENESYS was developed to examine the usefulness of a waste-exchange network in a nonmanufacturing district. We analyzed data from the Miyagi prefecture, a region without heavy industry. The data were collected from 77 companies using a questionnaire and interviews. A total of 33 possible waste exchange links arose after analysis using ZENESYS. However, these were frail networks that relied heavily on the construction industry. Two waste recycling technologies were selected from the ZENESYS database: reclaiming fuel from waste plastic and making construction materials from bottom ash. Evaluation of the environmental effects and economics of these two technologies showed they were both suitable for the environment, but no profit was made from reclaiming fuel from waste plastics. We concluded that in an area with no heavy industry, it may be difficult to adopt recycling technologies that have high environmental and economic performance. Materials are difficult to circulate among manufacturing industries even if a waste-exchange network exists, and resources are consumed during transportation and recycling.

Phase 1/11 study of bi-weekly irinotecan plus cisplatin in the treatment of advanced gastric cancer

OBJECTIVES

To conduct a phase I/II study of irinotecan with cisplatin to establish a recommended dose, and assess the safety, efficacy and feasibility of this regimen in unresectable advanced or recurrent gastric cancer.

PATIENTS AND METHODS

In the phase I portion of the study, patients received a fixed dose of cisplatin (30 mg/m2) with escalating doses of irinotecan, ranging from 30 mg/m2 to 70 mg/m2, on days 1 and 15. In the phase II portion of the study, 40 patients were evaluated for response and safety at the recommended dose.

RESULTS

Eighteen patients were enrolled in the phase I study. Dose-limiting toxicity (diarrhea and neutropenia) appeared at the irinotecan dose of 70 mg/m2. Therefore, the recommended irinotecan dose was 60 mg/m2. In the phase II study, 40 patients received cisplatin (30 mg/m2) plus irinotecan (60 mg/m2). Twenty-five out of 40 patients had received prior chemotherapy. The median number of cycles was 3.5. The response rate was 32.5% (13/40) overall, and 53.3% (8/15) in patients without prior chemotherapy. The median time to tumor progression (TTP) was 162 days. The median survival time was 288 days. Four patients (10%) developed grade 4 neutropenia and 3 patients (7.5%) developed grade 4 anemia. The only observed non-hematological toxicity at grade 3 or higher was diarrhea, seen in 2.5% (1/40) of the patients.

CONCLUSION

Bi-weekly administration of irinotecan and cisplatin is safe and active for the management of unresectable advanced or recurrent gastric cancer.

Human amniotic epithelial cells are morphologically homogeneous: enzymehistochemical, tracer, and freeze-substitution fixation study

We examined the fine subcellular morphology of human amniotic epithelial cells and attempted to answer the question as to whether amniotic epithelial cells consist of heterogeneous or homogeneous cells, which has long been controversial. Study subjects were fetal membranes from pregnant women (n=18) who abdominally gave birth to healthy infants at term (37.9+/-0.7 weeks of gestation, mean+/-sd). The methods employed were transmission electron microscopy, enzymehistochemistry, tracer permeability analysis, and freeze-substitution fixation. The labelings for acid phosphatase, cytochrome c oxidase, and CA++ATPase were seen in the lysosomes, mitochondria, and lateral plasma membranes, respectively. The staining distribution pattern of these three enzymes and the morphology of the organelle highlighted by these enzymehistochemistry did not differ among cells. Freeze-substitution fixation revealed that intercellular spaces in the amniotic epithelial cells were narrower than previously thought, but the tracers (horse radish peroxidase and lanthanum nitrate) fully entered these spaces. There were no variations in the tracer permeability among cells. All cells from freeze-substitution fixation exhibited the same morphological features. From these morphological viewpoints, we conclude that human term amniotic epithelial cells consist of a homogeneous cell population.

Chorion laeve trophoblasts of preeclamptic fetal membranes: histochemically detectable enzyme activities do not change at a subcellular level

We examined the subcellular localization of ADP-degrading activity and cytochrome c oxidase (CCO) activity in chorion laeve trophoblasts from term and near term human fetal membranes, and compared them with those from severe preeclamptic fetal membranes. The methods used for the detection of enzyme activities were the lead nitrate method for ADP-degrading activity and the diaminobenzidine method for CCO. Precipitates indicative of ADP-degrading activity were visible on surface microvillous plasma membranes of chorion laeve trophoblasts both from normal and preeclamptic fetal membranes. The intensity and distribution patterns were the same in the normal and preeclamptic subjects. CCO labeling was visible in almost all laeve trophoblastic mitochondria both in normal and preeclamptic cases. Previously, we demonstrated that in preeclamptic villous trophoblasts there were decreases in ADP-degrading activity and the presence of CCO-negative mitochondria, which were proposed to lead to dysfunction of each villous trophoblast, and finally to placental insufficiency in preeclampsia. Reductions or changes in enzyme intensities/distribution patterns, which are characteristic features of preeclamptic villous trophoblasts, were absent in chorion laeve trophoblasts in preeclampsia. These results suggest that in preeclampsia there are no, or at least less severe, abnormalities in the enzyme activities of chorion laeve trophoblasts, compared with villous trophoblasts, as far as enzyme-histochemically detectable enzymes are concerned.

Enzyme-cytochemically detectable glucose-6-phosphate dehydrogenase in human villous macrophages (Hofbauer cells)

Though various tissue macrophages possess high glucose-6-phosphate dehydrogenase (G6PD) activity, which plays an important role in their phagocytosis/bactericidal function, the presence of this enzyme in human placental villous macrophages (Hofbauer cells) has not been determined. We examined the ultrastructural localization of glucose-6-phosphate dehydrogenase (G6PD) in Hofbauer cells in first and second trimester placental villi, using a newly developed enzyme-cytochemistry (copper-ferrocyanide) method. Electron-dense deposits indicative of G6PD activity were clearly visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of Hofbauer cells. Positive and negative cytochemical controls ensured specific detection of enzyme activity. These observations indicated that Hofbauer cells abundantly possessed enzyme-cytochemically detectable G6PD activity. Hofbauer cell G6PD may play a role in placental defense, by supplying NADPH-dependent enzymes (i.e. nitric oxide synthase or NADPH oxidase) with NADPH. This enzyme may also fuel Hofbauer cells with ribose 5-phosphate during their cell proliferation and cell division.

Creatine kinase gene mutation in a patient with muscle creatine kinase deficiency

BACKGROUND

We describe a 56-year-old woman admitted to the hospital with a diagnosis of acute myocardial infarction without an increase of serum creatine kinase (CK) activity during her clinical course. She died on the 11th hospital day, and the diagnosis was confirmed by autopsy. The patient had had no previous muscular symptoms.

METHODS

Expression of the CK-muscle (CK-M) protein in cardiac tissue was examined by immunoblotting and immunochemical staining. CK-M mRNA expression was estimated by semiquantitative reverse transcription-PCR. Gene structure of CK-M was determined by Southern blotting and direct sequencing of 2251 bp. Existence of a point mutation in the CK-M gene was examined by restriction fragment length polymorphism analysis of PCR products (PCR-RFLP) in the patient and in 108 controls.

RESULTS

CK-M protein in the myocardial tissue of the patient was substantially lower (103 +/- 7 ng/mg protein) than in control myocardial tissue (35 800 +/- 2860 ng/mg protein). Immunoreactive CK-M in the patient tissue sample was 0.3% of the value for the control sample. CK-M mRNA was 53-fold less in the patient sample compared with the control. This very low expression of CK-M mRNA was considered to be the primary reason for CK-M deficiency. Direct sequencing revealed a point mutation at residue 54 in exon 2, which was specific for the patient. No other abnormalities were found in the CK-M gene of the patient.

CONCLUSIONS

This report identifies a molecular abnormality in human CK deficiency and discusses the physiologic relevance of CK-M.

Cytochemically detectable glucose-6-phosphate dehydrogenase is present in human fetal membrane chorion laeve trophoblasts

We examined the ultrastructural localization of glucose-6-phosphate dehydrogenase (G6PD), a NADPH-generating enzyme, in human fetal membranes at various gestational ages, using newly developed enzyme histochemistry (copper-ferrocyanide method). Electron-dense deposits indicative of G6PD activity were clearly visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of chorion laeve cytotrophoblasts at various gestational ages. Positive and negative cytochemical controls ensured specific detection of enzyme activity. These observations indicated that chorion laeve trophoblasts were the site of NADPH production. Chorion laeve trophoblast G6PD may play a significant role in fetal membrane physiology, by delivering NADPH to NADPH-dependent oxidoreductases which these cells possess.

Morphology of the mitochondria and endoplasmic reticula of chorion laeve cytotrophoblasts: their resemblance to villous syncytiotrophoblasts rather than villous cytotrophoblasts

We examined the morphological features of the mitochondria and endoplasmic reticula of chorion laeve cytotrophoblasts from term human fetal membranes, and compared them with those of syncytiotrophoblasts and cytotrophoblasts from human placental villi. Ultrastructural enzyme histochemistry of cytochrome c oxidase and glucose-6-phosphatase were used as cytochemical markers for these intracellular organelles. Chorion laeve cytotrophoblasts possessed abundant endoplasmic reticula, and small mitochondria with a few cristae, which were characteristic of villous syncytiotrophoblasts rather than villous cytotrophoblasts. As for these organellar structures, statistical analysis confirmed similarities between chorion laeve cytotrophoblasts and villous syncytiotrophoblasts, but significant differences between laeve cytotrophoblasts and villous cytotrophoblasts. Though these two cytotrophoblasts originated from one common cell in early placental development, they exhibited quite different organellar morphology during placental/chorioamniotic differentiation. Considering previous data, we concluded that chorion laeve cytotrophoblasts were metabolically active cells, similar to villous syncytiotrophoblasts, performing many functions in fetal membrane physiology.