Current and prospective understanding of clinical classification, pathomechanisms and therapy in pemphigus.
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Dermatology↗
Biomedical subjects
Yasuo Kitajima
Publications and source records attributed to Yasuo Kitajima.
A usual frameshift and delayed termination codon mutation in keratin 5 causes a novel type of epidermolysis bullosa simplex with migratory circinate erythema.
We report here two unrelated families in Japan and Korea having patients with a unique type of epidermolysis bullosa simplex and a novel mutation in the keratin gene KRT5, i.e., a frameshift and delayed stop codon inconsistent with any subtype described before. The patients showed migratory circinate erythema and multiple vesicles on the circular belt-like areas affected by erythema. Electron microscopy of skin biopsies showed a reduction in the number of keratin intermediate filaments in the basal cells without tonofilament clumping. We identified a novel heterozygous deletion mutation (1649delG of KRT5) in both cases. This deletion is predicted to produce a mutant keratin 5 protein with a frameshift of its terminal 41 amino acids and 35 amino acids longer than the wild-type keratin 5 protein due to a delayed termination codon. As the same abnormal elongated mutant KRT5 gene was found in the independent families, the predicted abnormal elongated keratin protein is likely to lead to an atypical clinical phenotype that has never been reported, possibly by interfering with the functional interaction between keratin and its associated proteins.
Amino Acid Sequence↗
Microcystic adnexal carcinoma with lymph node metastasis.
Microcystic adnexal carcinoma (MAC) affects predominantly the face and seldom metastasizes. We report a case occurring in the axilla of a 63-year-old male. Histology revealed the characteristic features of MAC. Eleven months after the excision, he underwent a reexcision with wide margins because of local recurrence. Histologically, the central area of the recurrent lesion revealed the typical histologic features of MAC, and the periphery showed a proliferation of irregular duct-like and glandular structures with a mixed pattern. Two lymph nodes that were not adherent to the tumor had metastatic tumor cells. The present case confirms that MAC can metastasize, although it may also be hypothesized that the recurrent lesion represented transformation into a higher-grade carcinoma.
Carcinoma↗
Aberrant expression of p16 and RB protein in eccrine porocarcinoma.
BACKGROUND: Eccrine porocarcinoma is a rare malignant tumor of the sweat gland and very little is known about its etiology and molecular basis. METHODS: To investigate the expression of p16 and retinoblastoma (RB) protein and their relationship, an immunohistochemical method was performed on nine eccrine porocarcinomas and five eccrine poromas. Furthermore, one case of eccrine porocarcinoma was analyzed for p16 gene mutation. RESULTS: A striking inverse correlation between p16 and RB expression was noted in all of the eccrine porocarcinomas and poromas. Strong immunoreactivity for p16 protein was observed in both nuclei and cytoplasm of the tumor cells in eight out of nine cases of eccrine porocarcinomas, while RB expression was negative in these cases. Conversely, one case of eccrine porocarcinoma did not show immunoreactivity for p16 protein, whereas RB protein was positive in the scattered nuclei. On the other hand, immunostaining of p16 was negative in all cases of five poromas, whereas RB-positive nuclei were sparse. No p16 gene mutation was detected in the investigated eccrine porocarcinoma case. CONCLUSIONS: These results indicate that detectable p16 protein and loss of RB protein are common occurrences in eccrine porocarcinoma lesions. Moreover, overexpression of p16 protein may be an additional, simple and useful diagnostic marker for eccrine porocarcinoma on routine laboratory screening.
Acrospiroma↗
Intramuscular lipoma within the temporal muscle.
A 61-year-old male presented with a 6-month history of a subcutaneous nodule on the left forehead, which had gradually enlarged. He had suffered from headaches from 20 days before the first visit. His medical history included hepatitis C virus infection. He had had no history of trauma in this area. Clinical examination showed a subcutaneous soft nodule, 15 x 15 mm in size, which was adjacent to the left superficial temporal artery (Fig. 1). Though this artery revealed strong pulsation, the nodule had neither pulsation nor tenderness. His headache was localized in the left temporal area. He had no complaints of fever or weakness. Clinically, these features suggested a pseudoaneurysm of the superficial temporal artery. We operated on him under local anesthesia. An incision through the skin and subcutaneous fat exposed a nodule located within the temporal muscle. The fine branches of the superficial temporal artery reached out to the nodule through the muscle. After ligation of the branches, we resected the nodule surrounded by muscular tissue. Histopathology showed the proliferation of mature adipose cells embedded in muscular fibers. These cells had no nuclear pleomorphism or mitoses (Fig. 2). The tumor tissue contained partial fibrosis and some muscular fiber bundles scattered between the adipose cells (Fig. 3). Intramuscular lipoma within the temporal muscle was diagnosed. His headache was reduced after the operation, and he has had no recurrence of the tumor for 16 months. The relationship between the tumor and his headache was unknown.
Humans↗
A novel nonsense mutation at E106 of the 2B rod domain of keratin 14 causes dominant epidermolysis bullosa simplex.
Epidermolysis bullosa simplex (EBS) is classified into three main types and is caused, in most cases, by missense mutations in the genes encoding keratin (K) 5 and K14. In this study, we clinically, ultrastructurally, immunohistochemically, and molecularly studied a patient with a dominant EBS, Köbner type. Using sequence analysis of genomic DNA, a novel K14 nonsense mutation was identified. A heterozygous mutation G1231T of KRT14 was found to be associated with the disease in the patient. The mutation created a premature stop codon (amino acid codon 411, residue 106 of the 2B helix) in the K14 molecule. This residue lies in a highly conserved region and was recently found to be absolutely required for molecular stability and intermediate filament assembly in K5 and K14. The E411X (E106X) heterozygous ablation, missing the last 16 amino acid residues of the 2B and the entire tail domain of K14, led to disease but did not result in clumping of keratin filaments. It is the first premature stop codon mutation of K14 found in dominant EBS.
Adult↗
Chicken ghrelin: purification, cDNA cloning, and biological activity.
In this study, we report the purification, cDNA cloning, and characterization of the novel growth hormone-releasing peptide, ghrelin, in the chicken (Gallus gallus). Chicken ghrelin is composed of 26 amino acids (GSSFLSPTYKNIQQQKDTRKPTARLH) and possesses 54% sequence identity with human ghrelin. The serine residue at position 3 (Ser(3)) is conserved between the chicken and mammalian species, as its acylation by either n-octanoic or n-decanoic acid. Chicken ghrelin mRNA is predominantly expressed in the stomach, where it is present in the proventriculus but absent in the gizzard. Using RT-PCR analysis, low levels of expression were also detectable in brain, lung, and intestine. Administration of chicken ghrelin increases plasma GH levels in both rats and chicks, with a potency similar to that of rat or human ghrelin. In addition, chicken ghrelin also increases plasma corticosterone levels in growing chicks at a lower dose than in mammals. The present results indicate that the stimulatory effect of ghrelin on GH secretion is evolutionarily conserved, whereas its effect on adrenal function seems to be unique in the chicken.
Amino Acid Sequence↗
Lack of plasminogen activator inhibitor-1 enhances the preventive effect of DX-9065a, a selective factor Xa inhibitor, on venous thrombus and acute pulmonary embolism in mice.
We have studied the physiological effects of DX-9065a, a selective factor Xa (FXa) inhibitor, and heparin in experimental venous thrombus and acute pulmonary embolism. Moreover, the effects of these compounds were also evaluated under the condition of plasminogen activator inhibitor-1 (PAI-1) deficiency. A thrombus was induced in the murine femoral vein. The compounds prolonged the time to occlusion in a dose-dependent manner. Pulmonary embolism was induced by continuous induction of venous thrombi in the left jugular vein. The mortality of mice increased time-dependently. Histological evidence of thromboembolism in the lung was obtained in all mice. Treatment with DX-9065a, but not heparin, reduced the mortality at 6 h after initiation of venous thrombi. In separate experiments, pulmonary thromboembolism was induced in PAI-1 knockout mice. The mortality in PAI-1 knockout mice was reduced compared with that of wild-type mice. Moreover, when DX- 9065a was administered to PAI-1 knockout mice with pulmonary thromboembolism, mice survived well without marked bleeding. These findings indicate that the dual inhibition of coagulation FXa and PAI-1 could be beneficial in the treatment of acute pulmonary embolism.
Acute Disease↗
Tinea barbae due to Trichophyton verrucosum.
A 25 year-old male, a dairy farmer, had noticed an annular scaly erythema on the left cheek since 3 weeks, and visited a dermatological clinic for the eruption. Diagnosis of tinea faciei was made and he was treated with oral anti-histamine medicine and by topical application of anti-fungal ointment. However, the eruption worsened and enlarged so that he visited the department of dermatology of Kumiai Hospital on October 19, 1997. He was in good general health. Physical examination disclosed papules and pustules with swelling and erythema on the chin and cheeks. The results of routine laboratory investigations were within normal limits except for white blood cell (9,800/mm(3)) and C reactive protein (2+). A small white-yellowish colony was grown on brain heart infusion agar culture of the biopsied specimen of the lower jaw. Histopathological features showed epidermal hyperplasia with elongation of rate ridges and granulomatous changes around hair follicles in the dermis with many mononuclear cells and giant cells, where many positive spores and fine filamentous structures with PAS and Grocott stains were seen. Based on clinical, histopathological and mycological findings, a diagnosis of Trichophyton verrucosum was made. The patient was treated with oral itraconazole (100 mg/day) for two months. There was a good clinical response and no recurrence during three years and six months.
Administration, Oral↗
Nodular fasciitis of the cheek.
Nodular fasciitis is a benign, fibrohistiocytic tumor most commonly arising on the trunk. Histopathologically it can be misdiagnosed as fibrosarcoma. We present a case report and review of the literature. Local excision to completely remove the tumor proved curative at 1 year of follow-up. We concluded that nodular fasciitis can be encountered on the cheek and should be regarded as a benign tumor.
Adult↗
Successful use of preserved sclera of eyelid reconstruction.
Eyelid surgery involving resection of more than half the eyelid and formation of full-thickness defect requires not only reconstruction of the anterior lamella, but also reconstruction of the posterior lamella, including the tarsal plate and palpebral conjunctiva. However, no reconstruction methods are of complete satisfaction. We describe our successful experience with 5 cases of eyelid reconstruction using preserved sclera and a report of a typical case of them. Based on our 5 case experience and literature, we compared eyelid reconstruction using preserved sclera to reconstruction using nasal septal or auricular cartilage in terms of external appearance and functions of the eyelid. The outcomes for reconstruction using preserved sclera in all 5 of our patients have been favorable. Previous papers as to this method, even though small in number, also reported no functional and esthetic problems. This method is recommended for eyelid reconstruction due to the good results and its simplicity.
Aged↗