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J Williams

Publications and source records attributed to J Williams.

At least 1,027 records · Page 57Linked to original sources
PubMed1982

The role of opiate peptides in the control of prolactin in the puerperium, and TSH in primary hypothyroidism.

The role of endogenous opiate peptides in puerperal hyperprolactinaemia, and in the control of TSH in hypothyroidism, has been investigated. Although exogenous opioids raise prolactin and TSH levels, 16 mg naloxone administered to women on days 2-4 of the puerperium produced no significant change in serum prolactin and the same dose of naloxone had no significant effect on serum TSH in six primary hypothyroid patients. There is little evidence that endogenous opioid peptides are major modulators of prolactin or TSH in man under these conditions.

Endorphins↗
PubMed1982

The primary structure of hen ovotransferrin.

Peptide sequences obtained from hen ovotransferrin are compared with the complete amino acid sequence of the protein deduced from a cDNA sequence (Jeltsch and Chambon, preceding paper). Of the 705 positions of the whole protein 605 can be matched by the peptide sequences. Some possible discrepancies between the two methods are pointed out. The two halves of the chain show marked similarities in their sequences with 37% identical residues. The positions of the 15 disulphide bridges are shown; there are 6 homologous bridges in each half of the molecule and 3 extra bridges which occur only in the C-terminal half. The terminal residues of the half-molecule fragments obtained by limited proteolysis are identified. The two domains are joined by a 9-residue connecting peptide. Sequence variability has been found at 9 positions. The sequence of hen ovotransferrin is compared with the partial available for human transferrin. From this some tentative conclusions about the identities of the metal-binding residues and about the evolution of transferrin are reached.

Amino Acid Sequence↗
PubMed1982

Functional assessment in partial hospitalization: clinical and administrative applications and implications after one year's utilization of the Framingham Functional Assessment Scale.

This paper presents the use of functional assessment as one response to the growing need for objective measures of outcome in psychiatric treatment. The Framingham Functional Assessment Scale was developed in 1979 as a functional assessment measure to form the basis of a client-oriented cost-outcome system for Medicaid reimbursement in Massachusetts. Clinical and administrative findings from 1 year's utilization of the scale are presented. Level of functioning (LOF) scores in a sample of 45 clients are analyzed to determine the amount of LOF change that occurred during the course of an intensive, 13-week, day-treatment program. Trends and patterns of LOF change are described. Utilization of functional assessment input/outcome data in administrative decision making is discussed, in light of increasing economic constraints in mental-health programs and concomitant demands for service accountability.

Analysis of Variance↗
PubMed1981

NH2-terminal structure and cleavage of guinea pig pro-C3, the precursor of the third complement component.

The NH2-terminal structures of the intracellular precursor of the third component of guinea pig complement (pro-C3), synthesized in macrophage cultures, and beta chain of C3 from guinea pig plasma were determined. Six of the first 16 residues of pro-C3 were identified by a microradiosequencing method. All six are nonpolar and are identical with the residues in beta chain of native plasma C3. This establishes beta chain as the NH2-terminal subunit in pro-C3. A comparison of primary structures of guinea pig and human C3 beta chains revealed identity of at least 8 residues within the NH2-terminal decapeptide. Incubation of plasmin with radiolabeled pro-C3 in macrophage lysate resulted in loss of pro-C3 and the generation of a two-chain molecule electrophoretically indistinguishable from native C3. These data indicate similarities between pro-C3 and the precursor of the fourth complement component, pro-C4, with respect to subunit organization, presence of phylogenetically conserved NH2-terminal regions, and the probable mechanism for generation of their respective native proteins.

Amino Acid Sequence↗
PubMed1981

The influence of pH on the equilibrium distribution of iron between the metal-binding sites of human transferrin.

The dependence of the metal-binding properties of transferrin on pH in the pH 6--9 range was investigated by urea/polyacrylamide-gel electrophoresis. Equations are presented for calculating the relative values of the four conditional site constants for the stepwise binding of iron to the two sites of transferrin and for calculating the equilibrium distribution of the protein among the four principal forms, apotransferrin, the C-terminal and N-terminal monoferric transferrins and diferric transferrin. The relative affinity of iron for the two sites and the co-operativity of iron-binding follow characteristic "pH titration' curves. A mathematical model that can account for the former behaviour is presented. In both cases the metal-binding sites are affected by the ionization of functional groups with apparent pKa values near physiological pH approx. 7.4. There is strong positive co-operatively in the release of protons from these groups. The results indicate that pH must be accurately controlled in studies of the differential properties of the two sites of the transferrin molecule.

Binding Sites↗
PubMed1981

Mature spinal ganglion cells are not sensitive to opiate receptor mediated actions.

Intracellular recording were performed in vitro from dorsal root ganglion cell bodies isolated from adult rats. A- and C-type cells were distinguished according to the conduction velocity of their axons. Bath perfusion of normorphine, methionine-enkephalin (M-E) or [D-Ala2,D-Leu5]-enkephalin (DADL) did not alter membrane potential, threshold potential for spike initiation or the spike waveform either before or after addition of Ba2+ and 4-aminopyridine. Perfusion with gamma-aminobutyric acid (GABA) depolarized A- and C-type cells and decreased input resistance. Picrotoxin antagonized this action. Morphine or M-E applied by perfusion never altered the GABA-induced depolarizations. Iontophoretically administered morphine reduced the GABA-induced depolarization without alteration of resting membrane properties or spike form, while M-E increased the GABA-induced depolarization. In about 50% of cells tested M-E applied iontophoretically produced a reversible hyperpolarization associated with an elevated input resistance (120-200% control). None of the effects produced by the opioids were antagonized by naloxone applied by perfusion or iontophoretically. These results suggest that the cell bodies of spinal ganglion cells of adult animals lack opiate receptors.

Action Potentials↗
PubMed1981

Predicting the adult daily sperm output after the first ejaculates in cockerels raised under different photoschedules.

In M33 cockerels, the rapid phase of testicular growth and the onset of sperm production were advanced either by increasing daylengths or an interrupted-night photoschedule; they were delayed by constant short days (8L). The results observed under constant long days (16L) were intermediate. In this strain, the cockerels maintained their mean testicular weight during the adult period while their daily sperm output (DSO) gradually declined. Individual variations in the DSO results were greater than individual variations in testicular weight. These variations did not appear to be influenced by the photoschedules. The differences in DSO observed between the best and the worst semen donors at the end of testicular development or thereafter remained relatively stable in ageing cockerels, except in birds submitted to increased photoperiods. This is the basis of the method described here for reliably choosing the best semen donors just before they are used as breeders.

Animals↗