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Biomedical subjects

J W Jacobs

Publications and source records attributed to J W Jacobs.

At least 163 records · Page 9Linked to original sources
PubMed1977

Acetylation of prostaglandin synthetase by aspirin. Purification and properties of the acetylated protein from sheep vesicular gland.

We previously presented evidence that aspirin (acetylsalicylic acid) inhibits prostaglandin synthetase by acetylating and active site of the enzyme. In the current work, we have labeled the enzyme from an aceton-pentane powder of sheep vesicular gland using [acetyl-3H]aspirin and purified the [3H]acetyl-protein to near homogeneity. The final preparation contains protein of a single molecular weight (85 000) and an amino-terminal sequence of Asp-Ala-Gly-Arg-Ala. The [3H]acetyl-protein contained 0.5 mol of acetyl residues per mol of protein based on amino acid composition but only a single sequence was found.

Acetylation↗
PubMed1977

Screening for organic mental syndromes in the medically ill.

A brief mental status questionnaire adapted specifically to diagnose diffuse organic diffuse organic mental syndromes on busy medical words is developed and tested for reliability and validity. When the 30-item questionnaire was given to 17 medical patients diagnosed by consultation spychiatrists as having a diffuse organic mental syndrome, all score 20 or less. With hospitalized psychiatric patients the questionnaire was able to differentiate between the "functional psychoses" and diffuse organic brain syndromes. When administered to 69 consecutive medical admissions, fully one third showed marked cognitive limitations. A sample of normals suggested that results may be contaminated by severe cultural or educational variances. We discuss the role of cognitive dificiencies in medical patients, and suggestions are made regarding the broad usefulness of this questionniare to a medical service.

Aged↗
PubMed1976

Purification, characterization, and partial amino acid sequence of nerve growth factor from cobra venom.

The nerve growth factor (NGF) from Naja naja (cobra) venom has been purified and its structure compared to the NGF from mouse submaxillary gland. A two-step purification procedure has been devised, consisting of a gel filtration step in 1 M acetic acid followed by chromatography of the active pool on carboxymethylcellulose at pH 5. The molecular weight of the native protein was found to be 28000, and this value was reduced by approximately one-half under denaturing conditions. These values are comparable to those obtained for mouse 2.5S or betaNGF. Tryptic peptide maps of S-[14C]carboxymethyl NGF gave the number of labeled peptides expected for a structure composed of two identical or very similar subunits. Thus, the quaternary structures of mouse and cobra NGF are the same. Cyanogen bromide (CNBr) treatment of Naja naja NGF produced three fragments, of which two were purified to homogeneity. These fragments and the whole protein were analyzed in the automated protein Sequencer. The amino-terminal CNBr fragment of the protein was also subjected to digestion by thermolysin and the resultant peptides were purified and characterized. These data plus those from the characterization of the tryptic peptides provided the basis of the construction of a tentative primary structure of Naja naja NGF which is approximately 60% identical with mouse NGF.

Amino Acid Sequence↗
PubMed1975

High sensitivity automated sequence determination of polypeptides.

We report the development of a high sensitivity Edman method for use in the automated protein sequenator. With the use of a radioactive coupling reagent, [35S]phenylisothiocyanate, and minor modifications in the sequenator program, sequence analyses have been performed on nanomole quantities of protein. The radioactive phenylthiohydantoin derivatives produced in the degradation are identified at the 10 to 100 pmol level by two-dimensional thin layer chromatographic procedures with autoradiography and are quantitated by scintillation counting. This high sensitivity approach, which is about 100 times more sensitive than conventional automated Edman procedures, has allowed continuous amino acid assignments for 15 or more cycles on quantities of protein less than 5 nmol. It has been employed in the NH2-terminal sequence analysis of several proteins whose sequences were previously undetermined.

Amino Acid Sequence↗
PubMed1975

Immunity to infections of the respiratory system in man and animals.

Itis probable that RS virus is an important etiological agent in the bovine respiratory disease syndrome. This is the conclusion of groups of workers in Europe and Japan. In this country, significant levels of neutralizing antibody have been detected in 81 percent of cattle tested, while paired sera groups showed seroconversions of between 17 and 29 percent. RS virus has also been isolated from diseased calves and such isolates produce pyrexia and rhinitis in experimentally infected calves. The virus is localised in the respiratory tract. Serum antibody responses have not been consistent but it is likely that moderate serum antibody levels indicate that the animal is protected. These antibody levels can be achieved by injection of a formalin inactivated antigen. Calves vaccinated in this way showed no definite evidence of exacerbation of disease when challenged with infectious virus.

Animals↗
PubMed1975

Experimental infection of calves with respiratory syncytial virus.

Three bovine isolates and one human isolate of RS virus were given intranasally to gnotobiotic, colostrum-deprived and conventional calves. All isolates produced a biphasic pyrexia associated with a serous nasal discharge. Virus was recovered from nasal secretions 4-10 days after inoculation from nasal, tracheal and bronchial mucosae and lung of animals killed 7-13 days after inoculation. Infection did not produce any macroscopic lesions, but histologically there was a focal degenerative rhinitis and a catarrhal bronchiolitis with the occasional formation of syncytia in bronchioles and alveoli.

Administration, Intranasal↗
PubMed1974

The amino-acid sequence of the amino-terminal 37 residues of human parathyroid hormone.

The sequence of the amino-terminal 37 residues of human parathyroid hormone has been established. The hormone used in these studies was isolated in highly purified form from parathyroid adenomata and was subjected to automated degradation in a Beckman sequencer. A high-sensitivity sequencing procedure employing (35)S-labeled phenylisothiocyanate of high specific activity as the coupling agent was used. The sequence obtained differs from that of bovine parathyroid hormone in three of the first 37 positions, and from that of porcine parathyroid hormone in two positions. A single human-specific residue was found (asparagine 16). The sequence obtained differs at three positions (22, 28, and 30) from the structure for human parathyroid hormone reported recently by Brewer et al. [(1972) Proc. Nat. Acad. Sci. USA 69, 3585-3588] and synthesized by Andreatta et al. [(1973) Helv. Chim. Acta, 56, 470-473] We have carefully reviewed our data, reported here in detail, on the sequence positions in dispute. We must conclude, on the basis of all available data, that the structure that we propose is the correct structure. The objective resolution of these discrepancies in structural analysis through further chemical and immunochemical studies is important, since synthesis of human parathyroid hormone, in which there is widespread interest for physiological and clinical studies, must be based on the correct sequence of the human hormone if the peptide is to be genuinely useful.

Adenoma↗
PubMed1974

The N-terminal amino-acid sequence of bovine proparathyroid hormone.

Proparathyroid hormone (calcemic fraction-A) is a biosynthetic precursor of parathyroid hormone in bovine glands. Limited amounts of the isolated prohormone have been obtained for the purpose of initial structural studies. The results of automated sequence analysis on two separate preparations indicate that the N-terminal region of the prohormone consists of the sequence Lys-Ser-Val-Lys-Lys-Arg followed by a sequence exactly corresponding to residues 1 to 34 of bovine parathyroid hormone. Also observed was a minor sequence (about 12% of the total) in which the N-terminal lysine was absent. These data suggest that more than one species of prohormone may exist. Due to the small quantities of sample available, the analyses were restricted to the N-terminal portion of the prohormone only. However, because the amino-acid composition of the prohormone indicates it to be a molecule containing more than 100 amino acids, the possibility remains that additional residues occur at the C-terminus. Thus, the prohormone structure based on these data is believed to consist of the hexapeptide sequence above, followed by the known sequence of the 84 residues in parathyroid hormone, possibly followed by an additional sequence of 10-15 residues.

Amino Acid Sequence↗