Trends in Investigator-Initiated Clinical Studies at a University Hospital after Enforcement of the 2018 Clinical Trials Act in Japan.

In April 2018, the Clinical Trials Act pertaining to investigator-initiated clinical trials was passed in Japan. The purpose of this study was to investigate activity in investigator-initiated clinical studies before and after enforcement of the new Clinical Trials Act. This was done by analysing the records of the Ethics Committee of Tokushima University Hospital, which reviews studies based on the Japanese government's Ethical Guidelines for Medical and Health Research Involving Human Subjects prior to the Clinical Trials Act, and records of the Certified Review Board established at Tokushima University under the Clinical Trials Act in 2018. The number of new applications to these two review boards during fiscal years 2015-2017 (pre-Act) and fiscal years 2018 and 2019 (post-Act) were used as an indicator of activity in investigator-initiated clinical studies. The number of new applications to the Ethics Committee was 303, 261, 316, 303, and 249 in 2015, 2016, 2017, 2018, and 2019, respectively. The data show that the total number of new interventional studies decreased from 50.3 in average in 2015-2017 (pre-Act) to 42 in 2018 and 40 in 2019 (post-Act), respectively. These results suggest that fewer interventional studies were started following enforcement of the new Clinical Trials Act. To confirm this trend and identify contributing factors, further studies are required. In addition, possible way, such as broader contribution of clinical research coordinators, to promote clinical studies in the new Clinical Trials Act era should be examined.

Cancer risk and genotype-phenotype correlation in Japanese patients with Cowden syndrome.

BACKGROUND: Cowden syndrome (CS) is an autosomal-dominant hereditary disorder caused by a germline PTEN variant and characterized by multiple hamartomas and a high risk of cancers. However, no detailed data on CS in Asian patients nor genotype-phenotype correlation have been reported. METHODS: We performed the first Japanese nationwide questionnaire survey on CS and obtained questionnaire response data on 49 CS patients. RESULTS: Patients included 26 females (median age 48 years). The incidence of breast, thyroid, endometrium, and colorectal cancer was 32.7%, 12.2%, 19.2% (among females), and 6.1%, respectively. The incidence of any cancers was relatively high among all patients (46.9%, 23/49), and particularly female patients (73.1%, 19/26), compared with previous reports from Western countries. Gastrointestinal (GI) polyps were more frequently found throughout the GI tract compared with previous studies. PTEN variants were detected in 95.6% (22/23) of patients; 12 in the N-terminal region (11 in phosphatase domain) and 10 in the C-terminal (C2 domain) region. The incidence of cancer in the C2 domain group was significantly higher than in the N-terminal region (phosphatase) group. All female patients with C2 domain variant had breast cancer. CONCLUSION: Our data suggest that Japanese patients with CS, particularly female patients and patients with C2 domain variant may have a high risk of cancers.

Big Insulin-like Growth Factor 2-Producing Tumor in a Hypoglycemic Dog.

A 10-year-old female Papillon dog that had previously developed a mammary tumor was admitted for treatment of a hypoglycemic attack. Blood examination showed severe hypoglycemia and decreased blood insulin concentration. Computed tomography indicated multiple tumors in the cranial and caudal lobes of the right lung. These tumors were resected surgically and diagnosed as pulmonary adenocarcinomas by histopathologic examination. Hypoglycemia was temporarily improved after the resection, but a hypoglycemic event occurred 2 months after the surgery. Immunohistochemistry of the tumor demonstrated the expression of insulin-like growth factor 2 in tumor cells. Western blot analysis revealed the expression of high-molecular-weight (big)-insulin-like growth factor 2 in the tumor region. Insulin-like growth factor 2 mRNA expression was also confirmed in the tumor using reverse transcription-polymerase chain reaction. These findings indicate the diagnosis of non-islet cell tumor-induced hypoglycemia caused by big-insulin-like growth factor 2 produced by the tumor in the dog. This report provides information on differentiating tumors that cause paraneoplastic hypoglycemia.

Sciatic Nerve Conductivity is Impaired by Hamstring Strain Injuries.

The aim of this study was to assess sciatic nerve conductivity in athletes with a history of hamstring strain injuries. Twenty-seven athletes with a history of hamstring strain injuries were included in the injured group. The control group consisted of 16 uninjured participants. We measured the proximal and distal latencies and calculated the sciatic nerve conduction velocity to evaluate neuronal conductivity. The results were expressed as median values and interquartile ranges. Both proximal latency and distal latency of the injured limb in the injured group were significantly longer than those of the uninjured limb (p<0.05). The nerve conduction velocity of the injured limb in the injured group was significantly lower than that of the uninjured limb (p<0.05). There were no significant side-to-side differences in the control group. Sciatic nerve conductivity impairments may exist in athletes with a history of hamstring strain injuries.

A case of vitiligo that followed the path of a varicose vein in the lower leg.

Vitiligo is an acquired chronic depigmenting disorder of the skin and is characterized by the destruction of melanocytes. One of the clinical features of vitiligo is that damage to normal skin frequently results in the formation of depigmented macules, which is known as Köebner's phenomenon (KP). Here, we presented a case of vitiligo, in which depigmented macules followed the course of a dilated varicose vein. Dilatation of blood vessels was considered to contribute to the development of the vitiliginous lesions as a trigger for KP. Any kind of skin injury can trigger KP, but this is only the second case in which a dilated blood vessel caused KP in vitiligo. J. Med. Invest. 71 : 177-178, February, 2024.

Prostatic stromal tumour of uncertain malignant potential in a dog.

An 11-year-old male Miniature Dachshund dog was presented with dyschezia. Computed tomography examination 35 days after the initial visit revealed a prostate mass (4.0 × 3.5 × 2.7 cm) and prostatectomy and orchiectomy were performed 13 days later. Grossly, the prostate was rubbery and the cut surface of the mass was swollen. The mass was whitish and demarcated from the surrounding tissues. Microscopically, the mass had a capsulate consisting of atypical spindloid stromal cells arranged in a phyllode pattern and also in a fasciculated pattern admixed with acinar ductal cells. Atypical stromal cells contained round-to-oval finely hyperchromatic nuclei that had distinct nuclei and abundant eosinophilic cytoplasm. Immunohistochemically, the atypical stromal cells were positive for vimentin, CD34, desmin, α-smooth muscle actin, progesterone receptor and androgen receptor but negative for cytokeratin AE1/AE3, p63, c-Kit, DOG-1 and SOX10. On the basis of these findings, the tumour was diagnosed as a prostatic stromal tumour of uncertain malignant potential.

Th2 and regulatory immune reactions contribute to IgG4 production and the initiation of Mikulicz disease.

OBJECTIVE: Mikulicz disease has been considered to be a subtype of Sjögren's syndrome (SS). However, recent studies have suggested that Mikulicz disease is an IgG4-related disease and is distinguishable from SS. In addition, it has been reported that both interleukin-4 (IL-4) and IL-10 induce IgG4 production and inhibit IgE. This study was undertaken to examine the expression of these cytokines in patients with Mikulicz disease and patients with SS. METHODS: Labial salivary gland (LSG) sections from 15 patients with Mikulicz disease and 18 patients with SS were examined for subsets of the infiltrating lymphocytes, expression patterns of messenger RNA (mRNA) for cytokines/chemokines, and relationships between the IgG4:IgG ratio and the expression of mRNA for IL-4 or IL-10. RESULTS: Immunohistochemical analysis showed lymphocyte infiltration of various subsets in the LSGs of SS patients, and the selective infiltration of IgG4-positive plasma cells and Treg cells in the LSGs of Mikulicz disease patients. The levels of mRNA for both Th1 and Th2 cytokines and chemokines in LSGs from patients with SS were significantly higher than in controls, while the expression of both Th2 and Treg cells was significantly higher in the patients with Mikulicz disease than in controls. Furthermore, the expression of IL-4 or IL-10 in the LSGs was correlated with the IgG4:IgG ratio. CONCLUSION: These results suggest that the pathogenesis of Mikulicz disease is different from that of SS. Mikulicz disease is a unique inflammatory disorder characterized by Th2 and regulatory immune reactions that might play key roles in IgG4 production.

Improvement of palmoplantar pustulosis lesions after angioplasty for Leriche syndrome.

Although a wide range of treatments have been used in the treatment of palmoplantar pustulosis (PPP), PPP is still very difficult to treat. We report a patient who had a dramatic reduction in PPP lesions after bypass surgery for Leriche syndrome. We assume that improved blood circulation had a crucial impact in reducing PPP lesions and suggest improving blood circulation could be another treatment option.

Clinical characteristics of Mikulicz's disease as an IgG4-related disease.

OBJECTIVES: Mikulicz's disease (MD) was considered to be a subtype of Sjögren's syndrome (SS), based on histopathological similarities. However, recent studies have indicated that patients with MD show high serum IgG4 concentration, and suggested that MD is one of "IgG4-related disease" and distinguishable from SS. Therefore, we clinically and histopathologically examined the disease states of MD and SS in detail. MATERIALS AND METHODS: Twenty patients with Mikulicz's disease and 18 with SS were comparatively studied to determine clinical characteristics in MD patients. RESULTS: Sialography in MD patients did not show the "apple-tree sign" typically seen in SS. Serologically, high serum IgG4 levels but not anti-SS-A or anti-SS-B antibodies were observed in MD. SS showed lymphocytic infiltration of various subsets with atrophy or severe destruction of the acini, while MD showed selective infiltration of IgG4+ plasma cells with hyperplastic germinal centers and mild acini destruction. Corticosteroid treatment of MD reduced IgG and IgG4 levels and improved salivary function. A negative correlation between disease duration and increasing rate of salivary flow was observed in MD. CONCLUSIONS: These results suggested that the pathogenesis of MD might be different from those of SS. CLINICAL RELEVANCE: early diagnosis and treatment of MD is important for the improvement of salivary function.

Podoplanin-positive cells located in the basal layer of Bowen disease include tumor cells with cancer stem cell properties.

Podoplanin (PDPN) is widely used as a marker of lymphatic endothelial cells. PDPN is also involved in tumor progression, and upregulated PDPN expression is often found in various cancers. In this study, we first immunohistochemically examined PDPN expression in 87 cases of Bowen disease. Positive expression was detected in 64.4% of Bowen disease specimens, and the positive cells were exclusively located in the basal layer and corresponded to palisaded basal cells (PBCs). PBCs have been considered to be residual normal keratinocytes so far, but PDPN expression in cancers is generally associated with poor clinical outcomes. We also examined PDPN expression in 27 cases of Bowen carcinoma. Diffuse and strong PDPN expression was detected in 22.2% of Bowen carcinoma specimens, and another 22.2% showed PDPN expression at the leading edges of tumor nests. These results prompted us to determine whether PDPN-positive cells are more tumorigenic than PDPN-negative cells. We cultured Bowen disease cells using a three-dimensional (3D) cell culture system and examined PDPN expression. In the cultured Bowen disease tissue, PDPN expression was again detected in the basal layer. Then, we isolated 1.2 × 105 PDPN-positive and -negative cells from the 3D organotypic culture of Bowen disease by fluorescence-activated cell sorting analysis and compared their tumorigenicity using 3D culture. The PDPN-positive tumor cells were able to regenerate Bowen disease tissue, but the PDPN-negative tumor cells were not. In addition, the regenerated Bowen disease tissue derived from the PDPN-positive cells exhibited PDPN expression in its basal layer, as the parental Bowen disease tissue did. These results indicate that PDPN-positive cells include tumor cells with cancer stem cell properties. Although the precise mechanism through which PDPN expression is involved in the pathogenesis of Bowen disease needs to be determined, PDPN may be a novel druggable target for Bowen disease.

Expression of receptor-type tumour endothelial marker 8 in carcinoma cells showing luminal progenitor-like phenotypes in canine mammary gland carcinomas.

This study aimed to investigate the expression of receptor-type tumour endothelial marker 8 (TEM8RT) in canine mammary gland carcinomas (CMGCs) using immunohistochemistry and to evaluate the association between carcinoma cell TEM8RT expression and tumour histological features, histological grades and the differentiation status of neoplastic epithelial cells. TEM8RT expression was more frequently detected in simple carcinomas (tubular and tubulopapillary) than in solid carcinomas, and it was significantly correlated with histological grade Ⅰ tumours and a low mitotic index. Additionally, TEM8RT+ carcinoma cells were more frequently found in CMGCs showing luminal progenitor-like phenotypes, such as Notch1+, CK19+/CK5+/CD49f+ and CK19+/CK5-/CD49f+. Double-labelling immunofluorescence detection techniques confirmed that most TEM8RT+ carcinoma cells expressed CD49f, Notch1 and CK19. However, TEM8RT immunoreactivity was not found in carcinoma cells expressing GATA3, which upregulates mature luminal cell differentiation. Furthermore, TEM8RT+ carcinoma cells were detected in a few CMGCs showing basal/stem cell-like phenotypes such as CK19-/CK5+/CD49f+ and CK19-/CK5+/CD49f-. These findings indicate that TEM8RT is expressed in luminal progenitor-like carcinoma cells in CMGCs. Since TEM8 enhances self-renewal in human mammary stem/progenitor cells, it also may be involved in maintenance of luminal progenitor-like carcinoma cells, resulting in prevention of their transition to basal/stem cell-like carcinoma cells and development of less malignant CMGCs. Therefore, TEM8RT may be useful for indicating prognostic outcomes and identifying the possible ontogeny of carcinoma cells in mammary gland tumours.

Expression of type VI collagen α3 chain in canine mammary carcinomas.

This study aimed to investigate the expression of type VI collagen α3 chain (COL6a3) in neoplastic cells of canine mammary gland carcinomas (CMGCs) using immunohistochemistry (IHC) and to evaluate the association between COL6a3 expression and tumor histological features, histological grades, and the differentiation status of neoplastic epithelial cells. COL6a3 expression in carcinoma cells was significantly associated with histologically low malignancy and low mitotic indices. In addition, COL6a3+ carcinoma cells were more frequently detected in simple carcinomas (tubular and tubulopapillary types) than in solid carcinomas. These findings indicate that reduced expression of COL6a3 in carcinoma cells contributes to the malignant phenotype in CMGCs. We also showed that COL6a3 expression in the carcinoma cells was more frequently detected in CK19+/CD49f + and/or CK19+/CK5+ tumors. In addition, COL6a3+/CK19+/CD49f + and COL6a3+/CK19+/CK5+ tumors consisted of CK19+/CD49f + and CK19+/CD49f- cells, and CK19+/CK5+ and CK19+/CK5- cells, respectively. Most of these tumors more frequently expressed GATA3, but not Notch1. These results indicate that COL6a3 is expressed in CMGCs containing both luminal progenitor-like and mature luminal-like cells and showing differentiation ability into mature luminal cells. It is possible that COL6 may be involved in the differentiation of luminal progenitor-like carcinoma cells into mature luminal-like carcinoma cells in CMGCs, which may suppresses the development of malignant phenotypes in CMGCs.

Establishment of a BRAF V595E-mutant canine prostate cancer cell line and the antitumor effects of MEK inhibitors against canine prostate cancer.

Canine prostate cancer (cPCa) is a malignant neoplasm with no effective therapy. The BRAF V595E mutation, corresponding to the human BRAF V600E mutation, is found frequently in cPCa. Activating BRAF mutations are recognized as oncogenic drivers, and blockade of MAPK/ERK phosphorylation may be an effective therapeutic target against BRAF-mutated tumours. The aim of this study was to establish a novel cPCa cell line and to clarify the antitumor effects of MEK inhibitors on cPCa in vitro and in vivo. We established the novel CHP-2 cPCa cell line that was derived from the prostatic tissue of a cPCa patient. Sequencing of the canine BRAF gene in two cPCa cell lines revealed the presence of the BRAF V595E mutation. MEK inhibitors (trametinib, cobimetinib and mirdametinib) strongly suppressed cell proliferation in vitro, and trametinib showed the highest efficacy against cPCa cells with minimal cytotoxicity to non-cancer COPK cells. Furthermore, we orally administered 0.3 or 1.0 mg/kg trametinib to CHP-2 xenografted mice and examined its antitumor effects in vivo. Trametinib reduced tumour volume, decreased phosphorylated ERK levels, and lowered Ki-67 expression in xenografts in a dose-dependent manner. Although no clear adverse events were observed with administration, trametinib-treated xenografts showed osteogenesis that was independent of dosage. Our results indicate that trametinib induces cell cycle arrest by inhibiting ERK activation, resulting in cPCa tumour regression in a dose-dependent manner. MEK inhibitors, in addition to BRAF inhibitors, may be a targeted agent option for cPCa with the BRAF V595E mutation.

Clinical Guidelines for Diagnosis and Management of Cowden Syndrome/PTEN Hamartoma Tumor Syndrome in Children and Adults-Secondary Publication.

Cowden syndrome (CS)/PTEN hamartoma tumor syndrome (PHTS) is a rare autosomal dominantly inherited condition caused by germline pathogenesis. It is associated with multiple hamartomatous lesions occurring in various organs and tissues, including the gastrointestinal tract, skin, mucous membranes, breast, thyroid, endometrium, and brain. Macrocephaly or multiple characteristic mucocutaneous lesions commonly develop in individuals in their 20s. This syndrome is occasionally diagnosed in childhood due to the occurrence of multiple gastrointestinal polyps, autism spectrum disorders, and intellectual disability. CS/PHTS can be diagnosed taking the opportunity of multigene panel testing in patients with cancer. Appropriate surveillance for early diagnosis of associated cancers is required because patients have a high risk of cancers including breast, thyroid, colorectal, endometrial, and renal cancers. Under these circumstances, there is growing concern regarding the management of CS/PHTS in Japan, but there are no available practice guidelines. To address this situation, the guideline committee, which included specialists from multiple academic societies, was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour, and Welfare, Japan. The present clinical guidelines explain the principles in the diagnosis and management of CS/PHTS, together with four clinical questions and the corresponding recommendations, incorporating the concept of the Grading of Recommendations Assessment, Development, and Evaluation system. Herein, we present an English version of the guideline, some of which have been updated, to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with CS/PHTS.

Interleukin-21 contributes to germinal centre formation and immunoglobulin G4 production in IgG4-related dacryoadenitis and sialoadenitis, so-called Mikulicz's disease.

OBJECTIVES: Interleukin (IL)-21 is mainly produced by CD4 T helper (Th) cells including Th2, Th17 and follicular helper T (Tfh) cells. Recent studies have reported that IL-21 is involved in the formation of germinal centres (GCs) and class switching of IgG4. It has been suggested that IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS), so-called Mikulicz's disease (MD), is distinct from Sjögren's syndrome (SS) and shows a high frequency of GC formation in salivary glands. In this study the expression of IL-21 in IgG4-DS and SS patients was examined. METHODS: Twelve patients with IgG4-DS, 15 with SS and 15 healthy subjects were screened for (1) ectopic GC formation in formalin-fixed labial salivary gland (LSG) biopsy samples; (2) expression of IL-21, Th2-, Th17- and Tfh-related molecules (cytokines, chemokine receptors and transcription factors) in LSGs; (3) relationship between IgG4/IgG ratio and mRNA expression of IL-21 in LSGs. RESULTS: mRNA expression of IL-21 and Bcl-6 in LSGs from patients with IgG4-DS was significantly higher than in patients with SS and controls. IL-21 and CXCR5 were detected by immunohistochemistry in or around GC in patients with SS and those with IgG4-DS. IL-21 was detected in infiltrating lymphocytes outside GC only in patients with IgG4-DS. Expression of IL-21 was consistent with that of Th2-related molecules while IL-17 was rarely seen in IgG4-DS. Furthermore, the expression of IL-21 in LSGs was correlated with the number of GC formations and the IgG4/IgG ratio in patients with IgG4-DS. CONCLUSIONS: These results suggest that overexpression of IL-21 by Th2 cells might play a key role in GC formation and IgG4 production in IgG4-DS.

COVID-19 health certification reduces outgroup bias: evidence from a conjoint experiment in Japan.

The psychological theory argues that serious threats cause negative attitudes from ingroups to outgroups. However, the factors that can reduce such outgroup bias caused by the health threats of a pandemic are unknown. Here, we provide evidence that health certifications to prove immunity or negative test result for COVID-19 reduce outgroup bias. Using a discrete choice experiment with a randomized conjoint design in Japan, we investigated public attitudes towards inbound travelers entering the country, including foreigners, immigrants, and tourists. We found that travelers carrying a vaccination certificate or a negative test result for COVID-19 have a higher probability or rating of being admitted to the country. These effects are the same size as those for travelers undergoing self-isolation. Thus, our results demonstrate that health certification can mitigate outgroup bias among ingroup members experiencing threats to health due to the COVID-19 pandemic. We anticipate that the findings would support the combined usage of vaccine passports and negative certificates to reopen the international borders.

Descriptive, injunctive, or the synergy of both? Experimenting normative information on behavioral changes under the COVID-19 pandemic.

Backgrounds: The effectiveness of citizens' behavioral changes to prevent the spread of SARS-CoV-2, such as avoiding large social events, relies on science communication from policymakers and collective action among peer citizens. Extant studies recognize the potential effects of information stimuli on citizens' behavioral changes, including what epidemiological experts request (injunctive information) and what surrounding people behave (descriptive information). Yet, they have insufficiently assessed the co-occurrence and possible interaction of multiple information stimuli. Methods: 1,819 Japanese citizens aged 18 or over were recruited for an experimental survey during March 1-3, 2021 and asked their views on a hypothetical wedding attendance in Japan while being exposed to randomly assigned normative information stimuli. Their willingness to attend a wedding asked before and after the intervention was measured. Infection risk perception was also asked as a mediating variable. Results: Findings suggest the constant supremacy of descriptive information and no synergistic effects in the interaction of multiple information stimuli. We also report that the effects of injunctive and descriptive information vary according to participants' risk perception, age, and trust in experts. Conclusion: Our experimental test enables a systematic assessment of multiple normative information and confirms the primacy of descriptive information as the main driver of behavioral change. Communication by medical experts has limitations but is still effective in specific categories of the population.

Bowen disease on the dorsum of the foot associated with human papillomavirus type 16.

A 94 years old Japanese female was presented to our hospital with a skin lesion on her left foot. A physical examination found a markedly hyperkeratotic reddish-brown plaque, measuring 3 cm in diameter. A biopsy specimen showed prominent papillomatosis, hyperkeratosis, and atypical keratinocytes throughout the epidermis. Individual cell keratinization, multinucleated keratinocytes, and many keratinocytes with clear cytoplasm were seen. We excised the lesion, and the skin grafting was used for covering the skin defect. We investigated whether human papillomavirus (HPV) was present in the lesion, and HPV 16 DNA was detected using the polymerase chain reaction. Immunohistochemical analysis showed several HPV-positive cells in the upper epidermis. In addition, the tumor cells showed strong and diffuse expression of p16INK4a. Bowen disease (BD) is an intraepidermal squamous cell carcinoma. The precise pathogenesis of BD is unclear, but it involves various factors. HPV infection is one of these factors and is a well-known cause of BD of the genitalia and fingers. It has been shown that some BD lesions occurring at other locations are also associated with HPV. Dysregulation of the Rb/p16INK4a pathway is considered to play an important role in HPV-induced BD, but the precise mechanism remains to be elucidated. J. Med. Invest. 69 : 152-154, February, 2022.