[A molecular study of the delta-F508 mutation and genetic analysis of a sample of cystic fibrosis patients].

The delta-F508 mutation was investigated in 39 index cases with cystic fibrosis (CF) using PCR-mediated site-directed mutagenesis. Eight patients were delta-F508 homozygous, 16 were delta-F508/unknown mutation compound heterozygous and 15 had unknown mutations in both alleles. Thus, delta-F508 was present in 41% of CF chromosomes and this frequency is lower than the observed among Northern European and North American Caucasians (70%), Southern Europe populations (50%) and Northern Mexico (59.

Frequency of delta F508 in a Mexican sample of cystic fibrosis patients.

This paper reports the frequency of the delta F508 mutation in a cohort of 50 Mexican patients with cystic fibrosis (CF). The mutation was detected by PCR mediated site directed mutagenesis. delta F508 was found in 39% of CF chromosomes, a frequency lower than that reported in Argentina and Spain.

Detection of the cystic fibrosis delta-F508 mutation at autopsy by site-directed mutagenesis.

In Caucasian populations cystic fibrosis (CF) is the most common autosomal recessive disorder. CF was previously considered rare in Mexico; however, the reported frequency is about 1% in autopsies. This discrepancy appears to be due to the inability to diagnose the illness during life.

The NMR solution structure of a Kunitz-type proteinase inhibitor from the sea anemone Stichodactyla helianthus.

The solution structure of a 55-amino-acid Kunitz-type proteinase inhibitor, ShPI, purified from the Caribbean sea anemone Stichodactyla helianthus, was determined by NMR spectroscopy. Nearly complete sequence-specific 1H-NMR assignments were obtained at pH 4.6 and 36 degrees C, and stereo-specific assignments were determined for 23 pairs of diastereotopic substituents.

Heme-CO religation in photolyzed hemoglobin: a time-resolved Raman study of the Fe-CO stretching mode.

Time-resolved resonance Raman spectroscopy has been employed to monitor geminate heme-CO rebinding in photolyzed HbCO. The excitation frequency was tuned to enhance the scattering from rebound heme sites 20-500 ns subsequent to CO photolysis. The behavior of vFe-C during ligand rebinding has important ramifications concerning heme pocket dynamics of the distinct equilibrium configurations of the six-coordinate heme sites.

Presence of D-alanine in proteins of normal and Alzheimer human brain.

This report constitutes the first demonstration of the presence of D-alanine in the proteins of the human nervous system. Proteins of the frontal lobe white and gray matter of human brains, both normal and Alzheimer subjects, contain D-alanine at concentrations between 0.50 and 1.

Susceptibility and resistance to autoimmunity following neonatal injection of semi-allogeneic spleen cells in rats.

A model of neonatal allotolerance was developed in rats. Brown-Norway (BN) neonates injected with semi-allogeneic (BN x Lewis) F1 hybrid spleen cells express a long-lasting chimerism and exhibit polyclonal B cell activation demonstrated by hyperimmunoglobulinemia affecting mainly IgE and IgG1, anti-laminin and anti-DNA autoantibodies as well as glomerulonephritis and anti-hapten antibodies. These abnormalities are autoregulated although the chimerism persists.

Effects of a high molecular weight toxin from the sea anemone Condylactis gigantea on cholinergic responses.

1. The effects of a high molecular weight toxin isolated from the sea anemone Condylactis gigantea (Condytoxina 2) on the cholinergic responses were studied in two different preparations: identified cells of a land snail and enzymatically dissociated mice sensory neurons. These neurons were studied using intracellular recording and concentration clamp techniques respectively.

Quantification of D-aspartate in normal and Alzheimer brains.

Using a new procedure to hydrolyze proteins without provoking racemization of the amino acids and using enzymatic methods to determine D- and L-aspartate (Asp), we have quantified the content of protein-bound D-aspartate (both D-aspartic acid and D-asparagine) of human brain white and gray matter proteins from normal and Alzheimer subjects. The D-enantiomer is present in brain proteins at mean concentrations between 0.48 and 0.

A specific sequence with a bulged guanosine residue(s) in a stem-bulge-stem structure of Rev-responsive element RNA is required for trans activation by human immunodeficiency virus type 1 Rev.

We demonstrate that both the in vitro RNA binding and in vivo trans activation functions of human immunodeficiency virus type 1 Rev regulatory protein Rev require the presence of a 9-nucleotide 5'-CACUAUGGG-3' RNA motif on its cognate target, the Rev-responsive element RNA. For optimal Rev recognition, this sequence must be presented as a stem-bulge-stem structure and must contain at least two G's, one of which must be unpaired, and include some or all of the CACUAU sequence upstream of the three G's. Distal mutations which result in the base pairing of the G's eliminate the Rev response.

Area postrema mediation of physiological and behavioral effects of lithium chloride in the rat.

The area postrema (AP), a chemoreceptor trigger zone for nausea and vomiting, has been implicated in taste aversion conditioning with LiCl. In addition to taste aversion acquisition, the present studies indicate that a number of other responses to LiCl administration are eliminated by lesions of the AP. These include a behavioral response, 'lying-on-belly' as well as two physiological responses, delayed stomach emptying and hypothermia.

Effects of G-6-PD deficiency, experimentally induced or genetically transmitted, on the sorbitol pathway activity. In vitro and in vivo studies.

Aldose reductase catalyzes the NADPH-linked reduction of hexoses to their respective sugar-alcohols, which are involved in the pathogenesis of "sugar-cataracts". In the lenses, the reaction catalyzed by G-6-PD is the source of NADPH supply blocking sugar-alcohol formation and consequently prevents or delays the onset of "sugar-cataracts". We have investigated the effect of G-6-PD deficiency, either experimentally induced or genetically transmitted, on the sorbitol accumulation in whole cells incubated in high glucose media and on the "sugar-cataracts" formation in a galactosemic rat model.

Diffuse bile duct tumors: guidelines for management.

The majority of patients with bile duct cancer have small focal adenocarcinomas localized to the upper, middle, or lower third of the bile duct. In contrast, a small subgroup of patients have been identified with bile duct tumors that are diffuse, involving multiple segments of the extrahepatic biliary tract. Among 186 patients with documented bile duct cancer treated at the UCLA Medical Center between 1954 and 1988, 13 patients (7%) had diffuse lesions.

Gastrointestinal complications after cardiac transplantation: a spectrum of diseases.

Cardiac transplantation has become an accepted treatment modality for end-stage cardiac failure. The gastrointestinal (GI) tract represents a potential source of posttransplant morbidity and mortality. To define the scope of this problem, records of all patients undergoing cardiac transplantation at UCLA between January 1984 and July 1989 were reviewed.

Resonance Raman investigation of a soluble cytochrome c552 from alkaliphilic Bacillus firmus RAB.

The environment of the heme site of a low-potential soluble cytochrome (c552) from alkaliphilic Bacillus firmus RAB has been characterized with resonance Raman scattering and compared to that of horse heart cytochrome c. The Raman data indicate that vibrational bands sensitive to the axial ligation of the heme, as well as modes sensitive to the heme peripheral environment in cytochrome c552, are distinct from those of horse heart cytochrome c. The spectra of cytochrome c552 display resonance Raman modes indicative of a methionine as the sixth ligand in the oxidized form, while the reduced form appears to contain a nitrogenous-based sixth ligand.

Progress in the development of a nutritional risk index.

The development of a 16-item nutritional risk index (NRI) is chronicled from its inception through its application in three studies designed to assess its reliability and validity. Study I involved a survey of 401 community-dwelling elderly in St. Louis, Missouri who were interviewed at baseline, 4-5 mo later, and 1 yr later.

Pathophysiology of experimental nephrotic syndrome induced by puromicyn aminonucleoside in rats. III. Effect of captopril, an angiotensin converting enzyme inhibitor, on proteinuria and sodium retention.

The effect of the converting enzyme inhibitor (CEI) (captopril, 50 mg/kg/day) on proteinuria (UProt), urinary aldosterone (UAldoV), plasma renin activity (PRA), plasma renin concentration (PRC), plasma angiotensinogen concentration (PAC), urinary sodium (UNaV), serum total protein, and body weight was studied for 21 days in an experimental nephrotic syndrome (NS) model induced in rats by a single injection (15 mg/100g) of puromycin aminonucleoside (PA). The effect of captopril on control rats without NS was also characterized. In control rats, captopril increased PRC and PRA, and decreased PAC; it had no effect on UNaV, UAldoV, UProt, total serum protein and body weight.

O2 and CO reactions with heme proteins: quantum yields and geminate recombination on picosecond time scales.

Picosecond time-resolved absorption spectroscopy and low-temperature studies have been undertaken in order to understand the nature of the intrinsic quantum yields and geminate recombination of carbon monoxide and oxygen to hemoglobin and myoglobin. We find that the photoproduct yields at 40 ps and long times (minutes) after photolysis at 8 K are similar; however, the yield of oxygen photoproducts is 0.4 +/- 0.

Structural and functional significance of inhomogeneous line broadening of band III in hemoglobin and Fe-Mn hybrid hemoglobins.

Near-infrared spectra of hemoglobin and Fe-Mn hybrid hemoglobins have been obtained at cryogenic temperatures. The charge-transfer (a2u(pi)----dzy) transition at approximately 760 nm (band III) has been found to be a conformationally sensitive indicator of the heme-pocket geometry in these species. Temperature, protein tertiary and quaternary structure, chain heterogeneity, and ligand rebinding subsequent to CO photolysis all affect the line width and position of this transition.

Pathophysiology of experimental nephrotic syndrome induced by puromycin aminonucleoside in rats. II. In vitro release of renin, angiotensinogen and aldosterone.

In vitro release of renin, angiotensinogen and aldosterone was studied in control (CT) and nephrotic rats. Nephrotic syndrome (NS) was induced by a single injection of puromycin aminonucleoside (PA). The in vitro systems used were: renal cortical slices (RCS), liver slices (LS) and adrenal glands, all incubated in Krebs-Ringer buffer.

Dynamics and reactivity of HbXL99 alpha. A cross-linked hemoglobin derivative.

Resonance Raman spectroscopy, transient absorption, and fluroescence techniques have been employed to investigate the structure and dynamics of the alpha-cross-linked hemoglobin derivative, HbXL99 alpha. The resonance Raman spectra of the deoxy form of HbXL99 alpha are identical to those of native NbA (VFe-His approximately 222 cm-1), which exhibit a T-state (low affinity) structure regardless of solvent conditions. The resonance Raman spectra of the transient heme photoproduct resulting from CO photolysis from HbXL99 alpha appear to have structures intermediate between deoxy-T and ligand-bound R structures (VFe-His approximately 222 cm-1).

[Primary hypothyroidism associated with a chiasmatic syndrome simulating a prolactinoma].

Three cases of primary hypothyroidism with optic chiasm compression due to pituitary hyperplasia are reported. Patients consulted for amenorrhea, galactorrhea and visual disturbances. The study of these patients disclosed a chiasm syndrome, persistent hyperprolactinemia, decreased thyroxine and triiodothyronine associated with elevated thyrotropin stimulating hormone in blood.