Reversible hydrogels from self-assembling artificial proteins.

Recombinant DNA methods were used to create artificial proteins that undergo reversible gelation in response to changes in pH or temperature. The proteins consist of terminal leucine zipper domains flanking a central, flexible, water-soluble polyelectrolyte segment. Formation of coiled-coil aggregates of the terminal domains in near-neutral aqueous solutions triggers formation of a three-dimensional polymer network, with the polyelectrolyte segment retaining solvent and preventing precipitation of the chain.

Malignant cough equivalent asthma: definition and case reports.

Background: Cough equivalent asthma is a cause for chronic cough and usually responds to corticosteroid therapy. Oral corticosteroids are employed in a diagnostic-therapeutic trial and inhaled corticosteroids are employed in maintenance therapy. In certain cases the cough may be especially severe and require escalated doses of oral corticosteroids for initial control.

Convergent control of serotonin transporter expression by glucocorticoids and cocaine in fetal and neonatal rat brain.

Serotonin plays a trophic role in brain cell differentiation. In this study, expression of the serotonin presynaptic transporter protein, which regulates the extracellular serotonin concentration, was measured with [3H]paroxetine in rats exposed to dexamethasone or cocaine prenatally. Within 24 h of a single dose of dexamethasone, significant increases were seen in fetal brain, and the effect persisted into the postnatal period.

Pediatric idiopathic anaphylaxis: experience with 22 patients.

Idiopathic anaphylaxis in the pediatric population is being increasingly recognized, with symptoms (and therefore classifications) the same as those described in adults. We present a series of 22 patients with special attention to considerations relatively unique to the pediatric population. Prednisone, hydroxyzine, and albuterol were used to control symptoms and induce remission.

Suitability of preadmission blood samples for pretransfusion testing in elective surgery.

Background: North American transfusion guidelines do not stipulate a time limit between drawing the specimen for pretransfusion testing and giving the transfusion to patients who have not received a transfusion or been pregnant in the preceding 3 months. British guidelines suggest that separated plasma and serum can be stored at -30 degrees C for up to 6 months, but they draw attention to the paucity of evidence concerning the use of stored samples. In Australia, transfusion guidelines recommend a maximum of 10 days' validity for pretransfusion specimens, which requires the patient to present for pretransfusion testing within 10 days of admission or to undergo retesting after admission, which in turn necessitates additional time in the hospital before operation.

Expression of homeobox genes, including an insulin promoting factor, in the murine yolk sac at the time of hematopoietic initiation.

The visceral yolk sac (YS), a simple bilayer structure formed during gastrulation, supplies blood cells and intestine- and liver-like functions to support embryonic growth. To better understand gene regulation in extraembryonic tissues, we examined the early murine YS for expression of the homeobox family of developmental transcription regulators. We identified a subset of known homeobox sequences (Hox 1l, b1, a9, c9, a7, b7, b8, a10, cdx-1, and PDX-1), as well as two novel homeodomains consisting of a fourth labial class Hox genes and one that matches the Antennapedia class on the amino acid level.

Maternal immunization to Gov system alloantigens on human platelets.

Background: Immunization to platelet alloantigens can occur during pregnancy or after the transfusion of blood components. Platelet alloantibodies can cause neonatal alloimmune thrombocytopenia and posttransfusion purpura. Transfusion-induced alloimmunization to a novel platelet alloantigen system, Gov, expressed on the 175-kDa glycosyl phosphatidylinositol-anchored platelet glycoprotein, CD109, was previously described.

An abundant nucleolar phosphoprotein is associated with ribosomal DNA in Tetrahymena macronuclei.

An abundant 52-kDa phosphoprotein was identified and characterized from macronuclei of the ciliated protozoan Tetrahymena thermophila. Immunoblot analyses combined with light and electron microscopic immunocytochemistry demonstrate that this polypeptide, termed Nopp52, is enriched in the nucleoli of transcriptionally active macronuclei and missing altogether from transcriptionally inert micronuclei. The cDNA sequence encoding Nopp52 predicts a polypeptide whose amino-terminal half consists of multiple acidic/serine-rich regions alternating with basic/proline-rich regions.

The significance of subnormal serum vitamin B12 concentration in older people: a case control study.

Objectives: To determine the clinical significance of subnormal serum vitamin B12 concentration in older people by comparing the hematological, neurological, and biochemical findings in patients with subnormal serum B12 with a control group with normal B12 levels.

Design: Clinical and laboratory assessment of hospital patients selected to represent a wide range of serum B12 levels.

Setting: Patients in the medical wards of two hospitals, one a general hospital and the other a geriatric hospital.

Left ventricular hypertrophy and QT dispersion in hypertension.

The interlead variation in QT length on a standard electrocardiograph reflects regional repolarization differences in the heart. To investigate the association between this interlead variation (QT dispersion) and left ventricular hypertrophy, we subjected 100 untreated subjects to 12-lead electrocardiography and echocardiography. Additionally, 24 previously untreated subjects underwent a 6-month treatment study with ramipril and felodipine.

Administration of pegylated recombinant human megakaryocyte growth and development factor to humans stimulates the production of functional platelets that show no evidence of in vivo activation.

This report describes the effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet production and platelet function in humans. Subjects with advanced solid tumors received PEG-rHuMGDF daily for up to 10 days. There was no increase in circulating platelet count at doses of 0.

Hereditary pancreatitis is caused by a mutation in the cationic trypsinogen gene.

Hereditary pancreatitis (HP) is a rare, early-onset genetic disorder characterized by epigastric pain and often more serious complications. We now report that an Arg-His substitution at residue 117 of the cationic trypsinogen gene is associated with the HP phenotype. This mutation was observed in all HP affected individuals and obligate carriers from five kindreds, but not in individuals who married into the families nor in 140 unrelated individuals.

Chronic cutaneous bacterial hypersensitivity.

Chronic cutaneous bacterial hypersensitivity (CCBH) is a syndrome of recurrent indolent inflammatory lesions that are caused by a hypersensitivity reaction to skin flora. It can cause significant physical and social distress to those affected, who often endure years of nondiagnostic evaluations and ineffective treatments. We report two additional cases of this syndrome.

Optimizing dose and scheduling of filgrastim (granulocyte colony-stimulating factor) for mobilization and collection of peripheral blood progenitor cells in normal volunteers.

To define an optimal regimen for mobilizing and collecting peripheral blood progenitor cells (PBPC) for use in allogeneic transplantation, we evaluated the kinetics of mobilization by filgrastim (recombinant met-human granulocyte colony-stimulating factor [r-metHuG-CSF]) in normal volunteers. Filgrastim was injected subcutaneously for up to 10 days at a dose of 3 (n = 10), 5 (n = 5), or 10 micrograms/kg/d (n = 15). A subset of volunteers from each dose cohort underwent a 7L leukapheresis on study day 6 (after 5 days of filgrastim).

Undifferentiated somatoform idiopathic anaphylaxis: nonorganic symptoms mimicking idiopathic anaphylaxis.

Background: Northwestern University's Division of Allergy and Immunology has had experience with the diagnosis and treatment of more than 350 patients with idiopathic anaphylaxis (IA). In 1992 we reported a group of patients with IA whose presentations mimicked IA, but IA and other organic causes were later excluded. Psychologic factors were suspected as the underlying problem.

Construction, cloning, and expression of synthetic genes encoding spider dragline silk.

Synthetic genes encoding recombinant spider silk proteins have been constructed, cloned, and expressed. Protein sequences were derived from Nephila clavipes dragline silk proteins and reverse-translated to the corresponding DNA sequences. Codon selection was chosen to maximize expression levels in Escherichia coli.

Neutralising antibodies after streptokinase treatment for myocardial infarction: a persisting puzzle.

Objective: To determine the development of titres of streptokinase (SK) neutralising antibodies after a single dose of SK, to establish when titres decrease to levels at which a second dose might be effective.

Design: Analyses of blood samples taken from patients at intervals after SK administration.

Setting: Australian public hospital.

Initiation of hematopoiesis and vasculogenesis in murine yolk sac explants.

The blood islands of the visceral yolk sac (VYS) are the initial sites of hematopoiesis in mammals. We have developed a yolk sac explant culture system to study the process of blood cell and endothelial cell development from extraembryonic mesoderm cells. No benzidine-positive cells or beta H1-globin mRNA expression was detected at the primitive streak or neural plate stage of development (E7.

Appropriateness of transfusions of red cells, platelets and fresh frozen plasma. An audit in a tertiary care teaching hospital.

Objective: To determine how current hospital practice for transfusions of red cells, platelets and fresh frozen plasma conformed with published criteria.

Design: Elaboration of criteria for transfusion from a review of the current literature; and analysis of the medical records of patients receiving transfusions of red cells (200), platelets (215), and fresh frozen plasma (260) during defined time periods in 1993.

Setting: A large tertiary care teaching hospital.

Biochemical indices of vitamin B12 nutrition in pregnant patients with subnormal serum vitamin B12 levels.

To determine the significance of the commonly observed fall in serum vitamin B12 levels during pregnancy, serum levels of the B12 metabolites methylmalonic acid (MMA) and homocysteine (Hcy) were measured in a group of 50 pregnant patients with subnormal serum B12 (range 45-199 pg/ml) and the results compared with those of 25 pregnant controls (serum B12(208-580) pg/ml). Mean values for serum MMA and total Hcy in the subnormal B12 group were 445.4 nmol/L and 7.