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Biomedical subjects

H Takashima

Publications and source records attributed to H Takashima.

At least 235 records · Page 13Linked to original sources

Deuterated oxytocins: the synthesis and biological properties of a crystalline analog of deamino-oxytocin deuterated in the 5-asparagine position.

This paper describes the synthesis and biological activity of [5-L-asparagine-alpha,beta,beta-d(3)]-deamino-oxytocin. The model peptide S-benzyl-beta-mercaptopropionyl-L- asparaginyl-alpha,beta,beta-d(3)-glycinamide was also prepared to observe the effect of the conditions of peptide synthesis on the deuterium content. It was found that normal synthetic procedures could be used without a significant loss in the deuterium content.The [5-L-asparagine-alpha,beta,beta-d(3)]-deamino-oxytocin had, within experimental error, the same avian vasodepressor and oxytocic activities as deamino-oxytocin itself.

Amino Acid Sequence↗

Physiological functions of the ascending spinal tracts in HTLV-I-associated myelopathy (HAM).

Physiological functions of the spinothalamic tract (STT) and the posterior column (PC) were studied in 19 Japanese patients with HTLV-I-associated myelopathy (HAM). The former was evaluated by pain-related somatosensory evoked potentials (SEPs) following CO2 laser stimulation, and the latter by conventional SEPs following electrical stimulation. Conduction velocity of STT and PC was significantly decreased in 9 and 14 patients, respectively, and more than half of them showed no clinical impairment of sensations (subclinical abnormality).

Adult↗

Nucleotide sequences of cloned cDNAs for two types of bovine brain substance P precursor.

The primary structures of two types of bovine brain substance P precursors have been determined. One precursor contains a sequence homologous to that of the amphibian peptide kassinin. This new tachykinin sequence is bounded by paired basic amino acids Lys-Arg, which suggests that, like substance P, it can be liberated from the precursor and may serve as an endogenous hormone or neuromediator in mammalian organisms.

Amino Acid Sequence↗

Screening for mutations in a genetically heterogeneous disorder: DHPLC versus DNA sequence for mutation detection in multiple genes causing Charcot-Marie-Tooth neuropathy.

PURPOSE: To determine the efficacy of denaturing high-performance liquid chromatography (DHPLC) for mutation detection in genetically heterogeneous diseases using Charcot-Marie-Tooth neuropathy as a model. METHODS: (1) Identification of the optimal conditions for mutation scanning by DHPLC using 50 known variants of PMP22, MPZ, GJB1 and EGR2. (2) Comparison of DHPLC with DNA sequencing for mutation detection in 168 patient DNA samples. RESULTS: We established the optimal conditions for screening PMP22, MPZ, GJB1, and EGR2 for mutations. Under optimized conditions, DHPLC was as sensitive as DNA sequencing and detected two mutations that were not identified by automated DNA sequence. CONCLUSIONS: DHPLC increases the efficiency and sensitivity of mutation screening in genetically heterogeneous diseases.

Adult↗

In vitro production of lysine from 2,2'-diaminopimelic acid by rumen protozoa.

Rumen protozoa can produce lysine from free 2,2'-diaminopimelic acid (DAP). However, the quantitative importance of this transformation has been disputed; lysine contents of protozoal incubation supernatants reported by Onodera & Kandatsu and Masson & Ling show a 26-fold difference. The in vitro experimental methods of both groups were compared to determine the causes of this difference. Lysine production was proportional to DAP concentration. Results with rumen protozoa from sheep or goats were similar. The incubation medium and deproteinizing procedure of the Welsh group gave a two-fold increase in lysine production compared with Japanese protocols. Omissions of rice starch from protozoal incubations slightly increased lysine production, whereas omissions of antibacterial agents resulted in varying, yet relatively small changes. The greatest cause of the difference was the number of rumen protozoa incubated. When this factor was taken into account, the difference in the maximum rates of lysine production between the Welsh and Japanese groups was only three-fold, namely 4.5 versus 15.0 nmol lysine/10(5) protozoa/h. Adding other amino acids to the incubations suggested that DAP uptake by rumen protozoa may occur via transport system ASC. The importance of DAP metabolism by protozoa as a source of lysine for ruminant host animals is discussed.

Amino Acids↗