Synthesis and 31P chemical shift identification of tripeptide active site models that represent human serum acetylcholinesterase covalently modified at serine by certain organophosphates.

Most organophosphorus (OP) insecticides impart their toxic action via inhibition of cholinesterases by reacting at an essential serine hydroxyl group. The inhibition process is dependent upon the reactivity, stereochemistry, leaving group, and the mechanism of phosphorylation and/or reactivation (or aging) inherent to the OP compound under consideration. Because a wide array of phosphorylated structures are possible following inhibition by an OP, a simple model system was sought to investigate the mechanistic details of these and related reactions.

Postoperative follow-up of pituitary adenomas after trans-sphenoidal resection: MRI and clinical correlation.

Our purpose was to correlate the morphological changes seen on MRI studies of the sellar region after trans-sphenoidal resection of pituitary adenomas with clinical and hormonal studies. Between January 1993 and March 1994, 16 patients with a pituitary adenoma (9 macroadenomas and 7 microadenomas) were subjected to trans-sphenoidal resection and included in a prospective study. The protocol consisted of MRI, hormonal and visual studies at the following times: immediately postoperative (1st week), 1st month, 4th month and 1st year after surgery.

The self-generated alcohol expectancies of Puerto Rican drinkers and abstainers.

Using data from an epidemiological study of mainland Puerto Rican drinking, this work compares the self-generated alcohol expectancies of Puerto Rican drinkers and abstainers. While positive expectancies are more characteristic of drinkers, especially "heavy drinkers," negative expectancies are more characteristic of abstainers, especially lifetime abstainers. Results are discussed in terms of the cultural influences on alcohol expectancies and the positivity bias in alcohol expectancy research.

Genetic control of the humoral immune response to xenografts. II. Monoclonal antibodies that cause rejection of heart xenografts are encoded by germline immunoglobulin genes.

The early phases of the rejection of xenografts exchanged between closely related species are dominated by a vigorous humoral immune response. We have recently used a linker-mediated polymerase chain reaction (LM-PCR) to generate Ig heavy and light chain-specific cDNA libraries to examine the Ig gene control of a prototypic IgM monoclonal antibody, HAR-1, that causes the hyperacute rejection of hamster xenografts. Recombinant clones from the library were screened directly from bacterial colonies by PCR and the nucleic acid sequences of the clones established.

[Complications associated with nonfunctioning pacemaker electrodes retained within the cardiovascular system].

Introduction And Objective: The aim of the present study was to evaluate the complications in patients with functionless pacing leads retained in the cardiovascular system.

Patients And Methods: We retrospectively studied 39 patients: 31 underwent surgery for electrical or mechanical failure (group I) and eight for cutaneous pocket infection (group II). The follow-up was 45 +/- 34 months.

Microlaparoscopy: a preliminary report.

A series of 30 microlaparoscopies performed under local anaesthesia and sedation are presented. The visualization of the pelvic organs was acceptable and the patients reported mild discomfort only. Microlaparoscopy may potentially replace macrolaparoscopy in selected cases.

Comparative assessment of the leprosy antibody absorption test, Mycobacterium leprae extract enzyme-linked immunosorbent assay, and gelatin particle agglutination test for serodiagnosis of lepromatous leprosy.

A comparative assessment of three serological methods for leprosy diagnosis (the fluorescent leprosy antibody absorption [FLA-ABS] test, the Mycobacterium leprae soluble-extract enzyme-linked immunosorbent assay [ELISA], and the M. leprae particle agglutination [MLPA] test) was carried out. The objective was to identify their performance in clinical and epidemiological diagnosis of leprosy.

Dietary fiber analysis of cassava using gravimetric methods.

We report the application of a method which combines digestion with pancreatin and neutral detergent treatment in the analytical study of dietary fiber from cassava. The use of pancreatin previous to the detergent extraction enabled rapid filtration, thus giving more reproducible results for neutral detergent fiber (NDF). Acid detergent fiber (ADF), hemicellulose, lignin and pectin were also determined.

The societal and organizational contexts of culturally sensitive mental health services: findings from an evaluation of bilingual/bicultural psychiatric programs.

The Hispanic mental health literature focuses mostly on cultural and clinical issues. This paper argues that researchers and practitioners concerned with mental health services for Hispanics and other minority groups need to pay more attention to the societal and organizational contexts that facilitate or impede the development of effective culturally sensitive psychiatric programs. Utilizing data from an evaluation of three New York psychiatric programs for seriously mentally ill (SMI) Hispanic patients, the paper discusses societal and organizational factors that influenced the programs' development.

Characterization of purified autoantibodies to the insulin receptor from six patients with type B insulin resistance.

Anti-insulin-receptor autoantibodies are present in the serum of patients with the type B syndrome of extreme insulin resistance. Sera from six patients with this syndrome were purified over protein-A agarose to remove insulin and other serum factors and obtain an immunoglobulin fraction. These purified fractions were used to quantitatively determine the antibodies' activity in three separate assays.

Simultaneous separation and determination of hydrocarbons and organochlorine compounds by using a two-step microcolumn.

The simultaneous separation and determination of a mixture of hydrocarbons and organochlorine compounds was successfully carried out by using sorption chromatography on a two-step microcolumn of silica and aluminium oxide for their fractionation, and a dual detector system. In addition to the separation and identification of hydrocarbons and heterocompounds containing nitrogen, oxygen and sulphur atoms, separation and identification of chlorinated hydrocarbons (dichlorobenzenes, p-chlorotoluene, hexachlorobutadiene, 1,2,4-trichlorobenzene and 2-chloronaphthalene), pesticides (chlorpicrin, aldrin, lindane, alpha- and beta-benzene hexachloride (BHC), endrin, dieldrin, endosulphan, methoxychlor) and herbicides (propanil, dichlobenil, trifluralin, difolatan) were achieved in mixtures containing polychlorinated biphenyl, strobane and chlordane.

[Maternal anemia and malnutrition and their relation to birth weight].

With a view to evaluating the effect of anemia and maternal undernourishment on birth weight, a sample of 691 pregnant women, from an assistential maternity hospital, in S. Paulo, Brazil, were studied at delivery. Anemia was found in 29.

Vascular anastomosis techniques in renal transplants.

In our series of 250 RT's 192 (76.8%) from living donors and 58 (23.27%) from cadaver donors, there were 207 (88.

Effect of temperature on the lactose hydrolytic capacity of a lactase derived from Kluyveromyces lactis.

In vitro studies of lactose hydrolysis in milk with 20-125 neutral lactase units (NLUs) carried out at 38.0 degrees C for 15 min with a beta-galactosidase derived from Kluyveromyces lactis (Lactaid, Lactaid Inc, Pleasantville, NJ) resulted in 85-95% of the hydrolysis observed with standard incubation conditions (24 h at 4-5 degrees C with 1000 NLU/L). Thirty-three lactose-maldigesting Guatemalan subjects, 16 children and 17 adults, were challenged with oral doses of lactose in milk (children aged less than 12 mo, 2 g/kg body wt; children aged 12-24 mo, 15 g/kg body wt; older children and adults, 18 g/kg body wt) preincubated for 20 min at 38 +/- 0.

The biomechanical effects of low-intensity ultrasound on healing tendons.

The effect of low-intensity ultrasound on the healing strength of tendons was studied in experimentally tenotomized, repaired and immobilized right tendo calcaneus (Achilles tendon) of 24 rabbits. Ten tendons were sonicated in continuous waves at a space-averaged intensity of 0.5 W cm-2 for 5 min every day.

[Drug use among students in Cali, Colombia].

The use of alcohol, tobacco, marihuana, cocaine, and bazuco was examined in a cross-sectional study of a random sample of 512 secondary-school students enrolled in public and private schools in Cali, Colombia. The overall prevalence of use for any of these substances was 59.38% in the public schools and 36.

Voltage-gated currents recorded from the surface of the frog optic nerve.

Macroscopic voltage-dependent currents were recorded from the surface of the intact optic nerve of Rana pipiens using the loose patch clamp technique. Depolarizing steps of more than 40 mV produced sodium-dependent TTX sensitive inward currents and a 4-AP and sodium sensitive fast outward current in addition to a slower outward current. Since the surface of the nerve is a glia limitans, it appears that the membranes of these astrocytes contain both voltage-sensitive sodium and potassium channels.

An outbreak of phototoxic dermatitis due to limes.

During the week beginning July 29, 1984, 12 children in a day camp in a suburb of Baltimore, Maryland, were noted to have skin eruptions consistent with phototoxic dermatitis. These eruptions were confined to the hands, wrists, and forearms, and appeared as discrete and confluent polymorphous patches and linear streaks. These eruptions were also macular, hyperpigmented, and nonpruritic.

Translational pauses during a spider fibroin synthesis.

The large ampullate glands of Nephila clavipes synthesize a tissue-specific fibroin for the web and dragline. Its secretory product migrates as one homogeneous band of approximately 320,000 daltons in denaturing electrophoresis. Similar analyses of the secretory epithelium reveal, in addition to the final product, a step ladder array of peptides in a highly reproducible and consistent pattern.