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Biomedical subjects

A Kawada

Publications and source records attributed to A Kawada.

At least 73 records · Page 4Linked to original sources

Isolation and molecular cloning of epidermal- and hair follicle-specific peptidylarginine deiminase (type III) from rat.

Peptidylarginine deiminase (PAD) is a post-translational modification enzyme that catalyzes deimination of arginine residues of proteins in the presence of calcium ions. There are three types of PAD in rodent tissues: PAD types I, II, and III [Terakawa et al. (1991) J. Biochem. 110, 661-666]. Type III enzyme was detected only in the epidermis and in hair follicles. In this study, we have purified PAD type III from 2-day-old rat epidermis by a four-step procedure that included soybean trypsin inhibitor-affinity chromatography. The enzyme was purified about 600-fold from the crude extract and the recovery was 23%. The final preparation of the enzyme gave only a single protein band on SDS-PAGE and showed an apparent molecular weight of 76,000. Subsequently, we cloned and sequenced the full-length cDNA encoding rat PAD type III by reverse transcription-polymerase chain reaction (RT-PCR) using degenerate oligonucleotide primers designed from the internal amino acid sequences and by the rapid amplification of the cDNA ends method. The composite cDNA sequence contained a 5' untranslated region of 42 bp, an open reading frame of 1,995 bases that encoded 664 amino acids (Mr=75,036), a 3' untranslated region of 1,063 bp, and part of a poly(A)+ tail. The entire reading frame sequence of rat PAD type III showed 51% homology with that of rat PAD type II, and the C-terminal region is highly conserved between the two types. The cloned gene was expressed in Escherichia coli cells to produce PAD type III, which had not only enzymatic activity, but also immunoreactivity against specific antibodies toward PAD type II. Furthermore, the specific expression of the enzyme in the epidermis and hair follicles was confirmed by RT-PCR assays of mRNAs from several tissues.

Amino Acid Sequence↗

[Clinical classification of ALS patients based on the total course of ALS--proposal of respiratory motor paralysis-preceded type and its significance].

Since the motor paralysis occurs in all motor systems in ALS, the clinicopathological findings and care of the patients living beyond the development of respiratory failure must be considered. We have divided the efferent motor systems into four groups, i.e., limb, bulbar, respiratory, and external ocular. In this study, 37 ALS patients were followed for more than two years with respirator, and the onset of motor paralysis in all four systems was observed in each patient. First, we classified the patients into three groups according to the number of paralyzed motor systems observed within six months from the onset of the first motor paralysis, and we discuss the patient's prognosis after the first motor paralysis. Twenty-one patients with paralysis of the respiratory motor system alone were categorized as respiratory paralysis-preceded type ALS (R-type ALS), four patients with paralysis of the bulbar motor system alone as bulbar paralysis-preceded type ALS (B-type ALS), and 12 patients with simultaneous paralysis of two or more motor systems as combined motor system paralysis type ALS (C-type ALS). The results showed that the prognosis of R-type ALS is slow progression and that of C-type ALS, rapid progression. Next, we investigated the time of occurrence of the first motor paralysis of the four motor systems in 37 patients, and we discuss the most vulnerable motor functions in ALS, i.e., the initial clinical presentations in ALS. The most frequent first motor paralysis was of the respiratory motor system, and the initial clinical manifestations in ALS were impairment of fine discriminating voluntary respiratory and limb motor functions. These findings could be explained by the rule of ALS involvements, according to which onto-genetically newer motor functions are lost earlier than the older ones. Based on the findings in this study, we concluded that ALS initially involves the ontogenetically new motor functions in "the first system" proposed by G. Holstege, whose anatomical structure is composed of pre-motoneurons and motoneurons in the brain stem and spinal cord.

Adolescent↗

Expression of cathepsin D and B in invasion and metastasis of squamous cell carcinoma.

To determine the involvement of proteinases with hydrolytic activity towards extracellular matrix and basement membrane, in invasion and metastasis of tumour cells, the expression of cathepsin D, an aspartic proteinase, and cathepsin B, a cysteine proteinase, was studied. Formalin-fixed paraffin-embedded specimens from 13 patients who had squamous cell carcinomas (SCC) with local recurrence, skin and/or lymph node metastasis were examined. Cathepsin D stained intensely as a granular pattern (mature enzyme) in tumour cells of 69% of primary lesions and all the secondary lesions of the patients with SCC. Cathepsin B stained more intensely in SCC cells of all of the primary and secondary lesions than in normal epidermis; staining patterns were almost diffuse (procathepsin B). Granular and diffuse patterns (mature enzyme of cathepsin D and procathepsin B, respectively) appeared in the outer and inner parts of tumour islands, respectively. The presence of the active mature form of cathepsin D and procathepsin B in metastatic skin lesions of SCC was confirmed by Western blotting analysis. The presence and localization of the active mature form of cathepsin D suggests that activated cathepsin D may be involved in the invasion and metastasis of SCC.

Blotting, Western↗

Photosensitivity from pyridoxine hydrochloride (vitamin B6).

We describe a 35-year-old female patient with photosensitivity due to pyridoxine hydrochloride (vitamin B6) in a multivitamin over-the-counter preparation. Photopatch and oral photochallenge tests using pyridoxine hydrochloride and UVA irradiation were positive. Larger doses for therapeutic use could cause photosensitivity.

Administration, Oral↗

Cathepsin B and D expression in squamous cell carcinoma.

To elucidate involvement of proteinases in malignancy of keratinocytes, expression of cathepsin B, a cysteine proteinase, and cathepsin D, an aspartic proteinase, was ascertained in formalin-fixed paraffin-embedded specimens of normal skin, squamous cell carcinoma (SCC). Bowen's disease, seborrhoeic keratosis and basal cell carcinoma (BCC). Presence of procathepsin B and an intermediate form of cathepsin D was confirmed by Western blotting and enzyme activity analysis. Cathepsin B stained more intensely in SCC tumour cells than in normal epidermis; staining patterns were diffuse, granular or both. Diffuse and granular patterns (procathepsin B and mature enzyme, respectively) appeared in inner and outer parts of tumour islands, respectively. Five of 20 cases of Bowen's disease showed diffuse enhanced cathepsin B expression; 20 cases of seborrhoeic keratosis or BCC did not. Cathepsin D stained intensely in tumour cells of half the SCC cases. The staining manner and distribution of cathepsins B and D was similar in the cytoplasm of cancer cells. No enhanced staining of cathepsin D was seen in any cases of Bowen's disease, seborrhoeic keratosis, or BCC. Coexistence and localization of active mature forms of cathepsins B and D suggests that cooperation between the two enzymes may play an important part in invasion of SCC.

Blotting, Western↗