Receptor protein-tyrosine phosphatase gamma is a candidate tumor suppressor gene at human chromosome region 3p21.

PTPG, the gene for protein-tyrosine phosphatase gamma (PTP gamma), maps to a region of human chromosome 3, 3p21, that is frequently deleted in renal cell carcinoma and lung carcinoma. One of the functions of protein-tyrosine phosphatases is to reverse the effect of protein-tyrosine kinases, many of which are oncogenes, suggesting that some protein-tyrosine phosphatase genes may act as tumor suppressor genes. A hallmark of tumor suppressor genes is that they are deleted in tumors in which their inactivation contributes to the malignant phenotype.

Comparison of EGF receptor sequences as a guide to study the ligand binding site.

While murine and human EGF-receptor (EGF-R) bind mammalian EGF with high affinity their chicken counterpart has approximately 300 fold reduced binding affinity towards mammalian EGF. We now cloned and sequenced the extracellular ligand binding domain of murine EGF-R in order to define the amino-acids which comprise the binding site for EGF. Comparison of human, murine and chicken EGF-R allows the identification of amino acid substitutions which are conservative and would not affect EGF binding, substitutions which are responsible for the low affinity binding of EGF to chicken EGF-R and those responsible for the high affinity binding of EGF to mammalian EGF-R.

Cloning of three human tyrosine phosphatases reveals a multigene family of receptor-linked protein-tyrosine-phosphatases expressed in brain.

A human brainstem cDNA library in bacteriophage lambda gt11 was screened under conditions of reduced hybridization stringency with a leukocyte common antigen (LCA) probe that spanned both conserved cytoplasmic domains. cDNA encoding a receptor-linked protein-tyrosine-phosphatase (protein-tyrosine-phosphate phosphohydrolase, EC 3.1.

Actuarial analysis of a uniform and reliable preservation method for viable heart valve allografts.

CryoLife has developed a method for cryopreserving allograft heart valves for transplantation. Since 1984, 6,907 valves have been processed and 4,216 transplanted. Documentation was available on 2,647 transplants, 11 of which were removed for structural deterioration and 13, for nonstructural deterioration.

A rapid method for estimating mean platelet survival time.

Platelet survival studies were performed in 27 consecutive subjects, and mean platelet life span was derived by computerized calculations of radioactivity in blood samples obtained daily for 9-11 days. These computer derived estimates were then correlated with the raw whole blood radioactivity data obtained for the first 3 days of each study. Data from the 48-hr point correlates with the computer estimates so that platelet survival data can now be reported in 2 days with 93% precision of the long method and without visual curve fitting.

FAS/FAE: focusing prevention on women at risk.

Consumption of alcohol during pregnancy is well recognized as a risk factor associated with adverse fetal development. While precise safe or dangerous levels of maternal drinking have not been identified, it is clear that the women who drink most heavily are at the greatest risk. Prevention of alcohol-related birth defects requires development of programs directed to the special needs of addicted women and their families.

Effect of midazolam and diazepam premedication on central nervous system and cardiovascular toxicity of bupivacaine in pigs.

To determine the effect of benzodiazepine premedication on central nervous system and cardiovascular effects of bupivacaine, the authors administered toxic doses of bupivacaine to awake spontaneously breathing pigs after intravenous premedication with midazolam (0.06 mg/kg), diazepam (0.15 mg/kg), or saline.

Somatic mutation and transcriptional deregulation of myc in endemic Burkitt's lymphoma disease: heptamer-nonamer recognition mistakes?

We examined the structure and expression of the myc protooncogene in DNA extracted from a primary (uncultured) endemic Burkitt's lymphoma sample designated eBL3. Dot and Northern (RNA) blot analyses demonstrated extreme levels of myc RNA in the eBL3 sample. Nearly complete sequence data of the altered myc locus isolated from eBL3 DNA demonstrated extensive mutations (duplications, insertions, and deletions) in critical myc regulatory regions.

Insertional mutagenesis of the myc locus by a LINE-1 sequence in a human breast carcinoma.

The proto-oncogene c-myc is the cellular homologue of the transforming sequence carried by the avian myelocytomastosis virus MC29. A growing body of evidence implicates structural and functional alterations in and around proto-oncogenes such as c-myc in tumorogenesis. Here we report that comparison of the structure of myc from a ductal adenocarcinoma of the breast and from normal breast tissue of the same patient (Sc) revealed a tumour-specific rearrangement of one myc locus and amplification of the other myc locus.

Chromium-51 dosimetry of lymphocytes labeled incidentally during nuclear medicine procedures.

Conventional dosimetry based on MIRD procedure fails to consider the localized energy deposition from the radionuclides decaying by the emission of Auger electrons. The cellular dosimetry of human peripheral blood lymphocytes labeled with 51 Cr, an Auger electron emitter, was calculated. Conventional dosimetric calculations reveal a dose of 0.

Strategies of hemopoietic stress adaptation within the medullary cavity.

Gravimetric determination of total bone water space was used as an index of available bone marrow space in mice following various specific stressors, i.e., splenectomy, hypoxia, bone fracture, and estrone-induced osteosclerosis.

Homologous recombination between autonomously replicating plasmids in mammalian cells.

The ability of autonomously replicating plasmids to recombine in mammalian cells was investigated. Two deletion plasmids of the eukaryotic-prokaryotic shuttle vector pSV2neo were cotransfected into transformed monkey COS cells. Examination of the low molecular weight DNA isolated after 48 hr of incubation revealed that recombination between the plasmids had occurred.

Circulating immune complexes and platelet IgG in various diseases.

Correlation between platelet associated IgG (PAIgG), platelet count, and plasma polyethylene glycol (PEG) precipitable IgG immune complex (IC) like material was tested in normal subjects and patients with immune thrombocytopenia (ITP), systemic lupus erythematosus (SLE) and various types of liver disease. Elevated IC were observed in 27% and 22% of ITP and recovered ITP, respectively. A significant inverse correlation between platelet count and PAIgG was demonstrable in the ITP group.

Homologous recombination between plasmids in mammalian cells can be enhanced by treatment of input DNA.

We have used the eukaryotic-prokaryotic shuttle vector pSV2Neo to demonstrate that cultured mammalian somatic cells have the enzymatic machinery to mediate homologous recombination and that the frequency of this recombination can be enhanced by pretreatment of the input DNA. Two nonoverlapping deletion mutants of pSV2Neo were constructed, each affecting the bacterial aminoglycoside 3'-phosphorylase gene (the neo gene), which confers resistance to aminoglycoside antibiotics on bacteria and resistance to the antibiotic G418 on mammalian cells. Mammalian cells transfected with either deletion plasmid alone yield no G418 -resistant colonies.

In-utero gunshot wound to the head. Use of intraoperative ultrasonography for localization of an intracerebral projectile.

Approaching full gestational age, a 1700-g male fetus sustained a penetrating gunshot wound to the left parietal region of the head while in utero. The child was delivered by emergency caesarean section. Initially in profound fetal shock and with almost no neurological function, the child was eventually stabilized.

Platelet-associated IgG in hepatitis and cirrhosis.

Increasing evidence is accumulating which indicates that immunological abnormalities contribute to the development of liver disease and its signs and symptoms. Platelet-associated IgG (PAIgG) levels were quantified in 42 patients with biopsy-proven liver disease of various etiologies to determine the relationship of thrombocytopenia to immunologic abnormalities in these disorders. Five of six nonthrombocytopenic patients with acute viral hepatitis B had elevated PAIgG.

Intraoperative spinal sonography: adjunct to metrizamide CT in the assessment and surgical decompression of posttraumatic spinal cord cysts.

Ten patients with prior spinal cord trauma were examined preoperatively by metrizamide computed tomography (CT) and were studied subsequently by intraoperative spinal sonography. On comparing intraoperative sonography with metrizamide CT, it was found that metrizamide CT tends to overestimate the size and number of posttraumatic cysts, that areas of myelomalacia on metrizamide CT correspond to areas of abnormal echogenicity on intraoperative sonography, and that intracyst septations are seen only on intraoperative sonography. By monitoring the position of the shunting catheter during surgery, intraoperative sonography can assure its proper intramedullary placement and demonstrate the successful decompression of the cyst.

Insulin-induced reactivation of an inactive herpes simplex thymidine kinase gene.

A line of mouse cells transformed with ultraviolet-irradiated herpes simplex virus type 1 and containing a methylated and inactive viral thymidine kinase (TK) gene was treated with insulin in an attempt to induce expression of the inactive gene. Insulin was found to be capable of inducing the inactive TK gene in these cells. The induction of the TK+ phenotype was dose dependent (from 1-100 micrograms of insulin per ml), and the TK activity induced was shown to be of viral origin.

Abdominal aspiration biopsies. Sonographic v computed tomographic guidance.

One hundred eighty-four diagnostic aspirations performed on 169 patients were reviewed (1) to define the decision process regarding which guidance method (sonography v computed tomography) should be used on any given patient, and (2) to determine, once a guidance method was chosen, its accuracy and complication rate. Sonographic guidance (84%) proved to be an effective method for obtaining a correct diagnosis in 98% (110/112) of cystic masses and 79% (34/43) of solid masses. Computed tomography (16%) was used when sonography could not identify the mass or when the mass was small, deeply located, and often solid.

The role of percutaneous aspiration in the diagnosis of pancreatic abscess.

Percutaneous aspiration should be performed on pancreatic/peripancreatic fluid collections when an abscess is suspected. Thirty-one percutaneous aspirations were performed on 21 such patients and seven (33%) proved to have an abscess. A Gram stain after the aspiration is important, as it can make an immediate diagnosis of an abscess.

Platelet associated IgG in uremia.

Platelet-associated IgG (PAIgG) levels, a useful adjunct for the evaluation of patients with immunologic mediated thrombocytopenia, were obtained in 36 patients with end stage renal disease undergoing maintenance hemodialysis. Twenty-five of the 36 had elevated PAIgG. Nine of the 36 were thrombocytopenic and only 3 of the 9 had elevated PAIgG.

Platelet-associated IgM levels in thrombocytopenia.

Platelet-associated IgG (PAIgG) and IgM (PAIgM) levels were quantitated in patients with thrombocytopenias of various etiologies. 32 of 34 patients with immune thrombocytopenia had elevated PAIgG, 8 of the 34 patients had elevated PAIgM levels. Only 1 patient suffering from immune thrombocytopenia had elevated PAIgM with normal PAIgG levels.

A rapid quantitation of platelet-associated IgG by nephelometry.

Platelet-associated IgG (PAIgG) was measured by a simple rapid nephelometric technique using washed solubilized platelets and commercially available, prestandardized reagents. Normal subjects with normal platelet counts had PAIgG levels of 2.1-6.