Can changing the timing of outdoor air intake reduce indoor concentrations of traffic-related pollutants in schools?

Traffic emissions have been associated with a wide range of adverse health effects. Many schools are situated close to major roads, and as children spend much of their day in school, methods to reduce traffic-related air pollutant concentrations in the school environment are warranted. One promising method to reduce pollutant concentrations in schools is to alter the timing of the ventilation so that high ventilation time periods do not correspond to rush hour traffic. Health Canada, in collaboration with the Ottawa-Carleton District School Board, tested the effect of this action by collecting traffic-related air pollution data from four schools in Ottawa, Canada, during October and November 2013. A baseline and intervention period was assessed in each school. There were statistically significant (P < 0.05) reductions in concentrations of most of the pollutants measured at the two late-start (9 AM start) schools, after adjusting for outdoor concentrations and the absolute indoor-outdoor temperature difference. The intervention at the early-start (8 AM start) schools did not have significant reductions in pollutant concentrations. Based on these findings, changing the timing of the ventilation may be a cost-effective mechanism of reducing traffic-related pollutants in late-start schools located near major roads.

Sulphonylureas and risk of cardiovascular disease: systematic review and meta-analysis

AIMS

Sulphonylurea use has been linked with increased cardiovascular disease risk; however, previous studies have been inconsistent. Type 2 diabetes independently increases risk for cardiovascular disease, so understanding the link between longer-term use of anti-diabetic medications and cardiovascular disease has important clinical implications.

METHODS

Literature search in MEDLINE and CENTRAL was conducted throughout December 2011 for clinical and observational studies that reported the association between sulphonylurea and cardiovascular disease events. Ratios (relative risk, odds ratios or hazard ratios) adjusted for potential confounders (concomitant medications, baseline cardiovascular risk, diabetes severity) were pooled using a random-effects model to yield relative risks and associated 95% confidence intervals.

RESULTS

This meta-analysis included 33 studies (n = 1,325,446 patients), followed for a range of 0.46-10.4 years. In all studies, compared with other oral diabetes drugs, sulphonylurea use was associated with a significantly increased risk of cardiovascular death (relative risk 1.27, 95% confidence interval 1.18-1.34, n = 27 comparisons) and composite cardiovascular event (including myocardial infarction, stroke, cardiovascular-related hospitalization or cardiovascular death) (relative risk 1.10, 95% confidence interval 1.04-1.16, n = 43 comparisons). In studies comparing sulphonylurea vs. metformin, these relative risks were 1.26 (95% confidence interval 1.17-1.35, n = 17 comparisons) and 1.18 (95%confidence interval 1.13-1.24, n = 16 comparisons), respectively.

CONCLUSIONS

Results suggest that sulphonylurea use may elevate the risk of cardiovascular disease among patients with diabetes. This meta-analysis expands the pool of studies evaluating cardiovascular mortality compared with prior observations while using adjusted estimates, and assessing an additional outcome of a composite cardiovascular event. This finding warrants consideration in clinical practice when other treatment options may be available.

Small volume laboratory on a chip measurements incorporating the quartz crystal microbalance to measure the viscosity-density product of room temperature ionic liquids

A microfluidic glass chip system incorporating a quartz crystal microbalance (QCM) to measure the square root of the viscosity-density product of room temperature ionic liquids (RTILs) is presented. The QCM covers a central recess on a glass chip, with a seal formed by tightly clamping from above outside the sensing region. The change in resonant frequency of the QCM allows for the determination of the square root viscosity-density product of RTILs to a limit of approximately 10 kg m(-2) s(-0.5). This method has reduced the sample size needed for characterization from 1.5 ml to only 30 mul and allows the measurement to be made in an enclosed system.

Draft protocol for testing calibration and quality control material used with automatic blood-counting apparatus

A large number of commercial preparations are now available for calibrating or checking the stability of automatic blood counters. Most of these preparations are supplied with 'stated' values though the methods for assigning these values are not described in sufficient detail to allow for an adequate assessment of the validity. The Haemocytometry Panel of the British Committee for Standards in Haematology are therefore proposing a draft protocol for testing calibration and quality control materials. Comments on the draft protocol are invited, either as letters to the Editor of Clinical and Laboratory Haematology or in confidence to the Chairman of the Haemocytometry Panel.

Prenatal genotyping for the RhD blood group antigen: considerations in developing an accurate test

Experience performing prenatal genotyping for RHD has shown that consideration must be given to developing a molecular test capable of detecting recombination/gene conversion events involving the RHD and RHCE genes that can lead to erroneous results. Out of 50 prenatal RHD tests performed over the past 5 years, four samples were encountered that gave false-positive results. In only one of the tests, incorrect results were issued to the physician. In the other three instances, the erroneous nature of the test results was revealed through the analysis of multiple regions of the RHD gene and, more importantly, because the mother, and sometimes the father, were tested in parallel with the fetus. In an extension of the observations obtained from the prenatal testing program, a large panel of RhD-negative blood donors were subjected to molecular analysis of the RHD gene. Of 1,183 donors screened, 187 were found to phenotype as RhD negative. Of the 187 donors confirmed RhD negative serologically, 22 (11.8%) were found to retain remnants of the RHD gene that, depending upon the characteristics of the molecular assay performed, could lead to a false-positive result in a genotyping assay. On the basis of the experience presented here, it is recommended that any molecular RHD assay include an analysis of multiple areas of the RHD gene so as to allow for the detection of recombination/gene conversion events between the RHD and RHCE genes. Moreover, it is strongly recommended that the mother (at a minimum) and father be subjected to molecular analysis simultaneously with the fetus to confirm that the known phenotypes of the parent(s) are consistent with their respective genotypes.

DNA analysis in a paternity case involving a triploid fetus

BACKGROUND

A parentage testing laboratory was asked to perform testing in a case of sexual assault that resulted in the conception of a child. Samples submitted to the laboratory included blood from the mother, the alleged father, and the fetus.

CASE REPORT

DNA typing was used to determine if the suspect in this sexual assault was the father of the expected child. DNA extracted from these samples was subjected to both restriction fragment length polymorphism and polymerase chain reaction/short-tandem repeat analysis at a total of 13 genetic loci. Examination of DNA profiles for selected markers suggested that the fetus was triploid. Triploidy was confirmed through the use of fluorescent in situ hybridization of chromosomes, employing three chromosome-specific alpha satellite probes and fetal trophoblast nuclei. Statistical interpretation of the test results required identifying a method for calculation that would consider two transmitted paternal genes. Attempts to modify the standard method of calculating a paternity index were unsuccessful, because it was not possible to distinguish between dispermy and diandry as the mechanism of conception. Therefore, the likelihood ratio was calculated as the reciprocal of the random men not excluded value or the proportion of the population that possesses all of the paternal markers observed in the triploid fetus.

CONCLUSION

Calculation of a likelihood ratio employing the exclusionary power of a collection of DNA markers appears to be the only method suitable for assigning weight to the significance of DNA matches between an alleged father and a child who is triploid.

Treatment of intractable pain with topical large-dose capsaicin: preliminary report

Complex regional pain syndromes (CRPS) and neuropathic pain are often poorly controlled by conventional pharmacologic interventions. We administered 8-methyl-N-vanillyl-noneamide (capsaicin) at doses of 5%-10% to individuals with such disorders in this trial. Previous limitations to trials with larger-dose, topical concentrations of capsaicin included intense burning sensations experienced after application. To enable patients to tolerate the high concentrations, we first performed regional anesthesia. All patients reported at least some relief. Of 10 patients, 9 obtained substantial analgesia that lasted 1-18 wk. At Week 1 after therapy, the mean verbal analog scale (VAS) scores decreased from 8.0 to 3.0. At Week 4 after therapy, mean VAS score was 4.5. Analgesia lasted from < 1 wk (1 patient) to more than 50 wk (1 patient). Patients received one to eight treatments. With one exception, patients receiving more than one treatment obtained additional relief with subsequent treatment. Pain responsive to opioids was the only side effect of treatment. Large-dose capsaicin administered with regional anesthesia may effectively minimize refractory CRPS and neuropathic pain. A double-blind, placebo-controlled study in patients with bilateral peripheral neuropathy using epidural anesthesia with and without large-dose topical capsaicin is in progress.

IMPLICATIONS

Sensory neuropathies are associated with many diseases. Pain from these disorders can produce greater disability than the primary disease processes themselves. Currently available therapies are limited. However, the intermittent application of large-dose topical capsaicin may provide significant pain relief, decrease chronic analgesic dependence, and decrease aggregate health care expenditures.

Space product development: bringing the benefits of space down to Earth

In fulfilling the National Aeronautics and Space Administration's (NASA) responsibility to encourage the fullest commercial use of space the Space Product Development (SPD) Program, within the Microgravity Research Program Office (MRPO) located at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama, is managing an organization of Commercial Space Centers (CSC's) that have successfully employed methods for encouraging private industries to exploit the benefits of space-based research. Unique research opportunities of the space environment are being made available to private industry in an effort to develop new, competitive products; create jobs; and enhance the country's quality of life. Over 200 commercial research activities have been conducted in space by the CSC's and their industrial partners during the last several years. The success of this research is evidenced by the increasing amount of industrial participation in commercial microgravity research and the potential products nearing marketability.

Prolonged muscle weakness following emergency tonsillectomy in a patient with familial periodic paralysis and infectious mononucleosis

A thirteen-year-old girl with normokalaemic familial periodic paralysis (FPP) suffered life threatening upper airway obstruction secondary to tonsillopharyngitis resulting from infectious mononucleosis (IM). Emergency tonsillectomy was performed, but her postoperative course was complicated by persistent muscle weakness requiring a very prolonged period of artificial ventilation.

Low-cost high-resolution fast spin-echo MR of acoustic schwannoma: an alternative to enhanced conventional spin-echo MR?

PURPOSE

To determine whether unenhanced high-resolution T2-weighted fast spin-echo MR imaging provides an acceptable and less expensive alternative to contrast-enhanced conventional T1-weighted spin-echo MR techniques in the diagnosis of acoustic schwannoma.

METHODS

We reviewed in a blinded fashion the records of 25 patients with pathologically documented acoustic schwannoma and of 25 control subjects, all of whom had undergone both enhanced conventional spin-echo MR imaging and unenhanced fast spin-echo MR imaging of the cerebellopontine angle/internal auditory canal region. The patients were imaged with the use of a quadrature head receiver coil for the conventional spin-echo sequences and dual 3-inch phased-array receiver coils for the fast spin-echo sequences.

RESULTS

The size of the acoustic schwannomas ranged from 2 to 40 mm in maximum dimension. The mean maximum diameter was 12 mm, and 12 neoplasms were less than 10 mm in diameter. Acoustic schwannoma was correctly diagnosed on 98% of the fast spin-echo images and on 100% of the enhanced conventional spin-echo images. Statistical analysis of the data using the kappa coefficient demonstrated agreement beyond chance between these two imaging techniques for the diagnosis of acoustic schwannoma.

CONCLUSIONS

There is no statistically significant difference in the sensitivity and specificity of unenhanced high-resolution fast spin-echo imaging and enhance T1-weighted conventional spin-echo imaging in the detection of acoustic schwannoma. We believe that the unenhanced high-resolution fast spin-echo technique provides a cost-effective method for the diagnosis of acoustic schwannoma.

Relief of tension subcutaneous emphysema using a large bore subcutaneous drain

We report a case of subcutaneous emphysema following multiple attempts to cannulate both subclavian veins for pacemaker insertion. Initial bilateral pneumothoraces were complicated by subcutaneous emphysema which became so severe that respiration and cardiac output became seriously impaired. The insertion of a single large bore subcutaneous drain produced a dramatic improvement. The aetiology, complications and management of tension subcutaneous emphysema are discussed.

Religion and children with disabilities

Religion as a personal coping resource used by parents of infants and toddlers with disabilities has received some attention in recent literature. This exploratory study involved indepth interviews of 12 parents who had children with disabilities ranging in age from 15 months to 30 years. The ways in which religion can be used as a coping resource across the life-cycle are exemplified through excerpts from these interviews. Prayer, church attendance, and specific religious beliefs were identified as sources of support which helped some parents feel a growing sense of hope and strength. Suggestions for future research are discussed.

Single-base substitutions give rise to a five-banded DNA profile at the D10S28 locus

BACKGROUND

DNA profiles from variable number of tandem repeat (VNTR) loci typically are composed of two bands, one derived from each member of the homologous pair of chromosomes. DNA profiles composed of more than two bands result from mutations, and the question arises as to the mechanism underlying these unusual multi-banded DNA profiles.

STUDY DESIGN AND METHODS

An alleged father in a paternity test was found to have a five-banded DNA profile at the D10S28 locus when his DNA was subjected to single-locus restriction fragment length polymorphism mapping with the restriction enzyme Pvu II.

RESULTS

Several results suggest that this complex DNA profile is the result of several single-base changes within the VNTR locus. First, there was no evidence of partial digestion of the DNA with Pvu II. Furthermore, the multi-banded allele happened, in this case, to be transmitted to the child, who also showed a five-banded pattern composed of four bands inherited from the alleged father and one band inherited from the mother. Second, digestion of this DNA with Hae III resulted in the visualization of just two bands at the D10S28 locus.

CONCLUSION

The results confirm the notion that mutations at VNTR loci are not always the result of additions or deletions of tandem repeats, but that they can also involve single-base substitutions either within or flanking VNTR loci that give rise to atypical DNA profiles and new alleles at the locus.

Isolation of tumor cell-specific single-chain Fv from immunized mice using phage-antibody libraries and the re-construction of whole antibodies from these antibody fragments

Enhanced expression of epidermal growth factor receptor (EGFR) occurs on a variety of malignant tissues thus making anti-EGFR antibodies possible agents for the diagnosis and therapy of human tumors. Standard hybridoma technology has been used successfully to isolate anti-EGFR antibodies from immunized mice and rats. This report demonstrates that phage-antibody libraries are an alternative, and more versatile, method for isolating antibodies from immunized mice. Anti-EGFR antibodies were isolated from phage-antibody libraries constructed not only from the spleen of an immunized mouse but also from the draining lymph node of an immunized mouse and from in vitro immunized mouse cells. Two of the single-chain Fv isolated from the phage-antibody libraries were engineered to create partially humanized whole antibody molecules.

Metastatic choriocarcinoma: correlation of MRI, CT, and angiography

We have described a 46-year-old woman with metastatic choriocarcinoma, anemia, and a liver mass. She subsequently had widespread metastatic disease and died despite chemotherapy. Without an antecedent history of pregnancy, her clinical presentation posed a diagnostic dilemma. This case emphasizes the importance of including choriocarcinoma in the differential diagnosis of liver masses in women of childbearing age and of correlating CT, MRI, and angiographic findings.

A preliminary assessment of epidural chloroprocaine for day procedures

Twenty-five patients underwent epidural anaesthesia with a new formulation of chloroprocaine 3% (1.0-1.5 ml x 10 cm body height-1) for a variety of day procedures. The mean (range) duration of surgery was 17 (5-35) min. The mean (range) time taken to establish maximal block was 16 (15-21) min and the mean (range) time to ambulation was 78 (55-95) min after administration of chloroprocaine. Twenty-three patients experienced a decrease in systolic arterial blood pressure of up to 15% of baseline values with another two decreasing by up to 25%. Two patients complained of severe backache immediately after operation and a further 16 and four patients reported mild or moderate backache respectively. Operating conditions were excellent in all but one patient and 23 patients said they would be happy to have the same anaesthetic again.

Genetic differences at four DNA typing loci in Finnish, Italian, and mixed Caucasian populations

Highly polymorphic segments of the human genome containing variable numbers of tandem repeats (VNTRs) have been widely used to establish DNA profiles of individuals for use in forensics. Methods of estimating the probability of occurrence of matching DNA profiles between two randomly selected individuals have been subject to extensive debate regarding the possibility of significant substructure occurring within the major races. We have sampled two Caucasian subpopulations, Finns and Italians, at four commonly used VNTR loci to determine the extent to which the subgroups differ from each other and from a mixed Caucasian database. The data were also analyzed for the occurrence of linkage disequilibrium among the loci. The allele frequency distributions of some loci were found to differ significantly among the subpopulations in a manner consistent with population substructure. Major differences were also found in the probability of occurrence of matching DNA profiles between two individuals chosen at random from the same subpopulation. With respect to the Finnish and Italian subpopulations, the conventional product rule for estimating the probability of a multilocus VNTR match using a mixed Caucasian database consistently yields estimates that are artificially small. Systematic errors of this type were not found using the interim ceiling principle recently advocated in the National Research Council's report [National Research Council (1992) DNA Technology in Forensic Science (Natl. Acad. Sci., Washington)]. The interim ceiling principle is based on currently available racial or ethnic databases and sets an arbitrary lower limit on each VNTR allele frequency. In the future the ceiling frequencies are expected to be established from more adequate data acquired for relevant VNTR loci from multiple subpopulations.

Partial attenuation of the pressor response to endotracheal intubation. A comparison of the effects of intravenous clonidine and fentanyl

In a randomized, double-blind placebo controlled study, intravenous clonidine, fentanyl and saline were compared for both their effect on the cardiovascular response to intubation, and early post-operative pain. The patients treated with fentanyl and clonidine were more sedated and the requirements for induction agents were lower compared to the control group. On intubation, both the active treatments resulted in a smaller increase in both heart rate and mean arterial pressure compared to the control group. There was no significant difference in recovery times in the three groups. Although the time to first request for analgesia was longer in the clonidine group compared to both the fentanyl and saline groups, the difference in morphine requirements between the groups was not significant. The differences between the two active treatments were not significant, and clonidine offered no additional benefits over fentanyl for this purpose.

Gastric emptying during lumbar extradural analgesia in labour: effect of fentanyl supplementation

We measured gastric emptying (by paracetamol absorption) and duration of analgesia in 30 women in labour after extradural injection of 0.375% bupivacaine 10 ml either alone or combined with fentanyl 100 micrograms. Treatment was administered double blind by random allocation after the first request for analgesia. The median (range) times to maximal serum concentration of paracetamol were 60 (15-90) min and 75 (30-180) min after administration in the control and fentanyl groups, respectively (P = 0.026), and corresponding mean (95% confidence interval) maximal concentrations of paracetamol were 27.3 (18.8-35.8) micrograms ml-1 and 18.0 (15.1-20.9) micrograms ml-1 (P = 0.020). Mean duration of analgesia, from the first extradural bolus until return of pain in those given bupivacaine alone was 113 (87-139) min and 154 (131-176) min when fentanyl was added to the local anaesthetic (P = 0.016). These results confirm the prolongation of analgesia after fentanyl supplementation of lumbar extradural analgesia, but indicate that it results in delayed gastric emptying.

Attenuation of the pressor response to tracheal intubation in hypertensive proteinuric pregnant patients by lignocaine, alfentanil and magnesium sulphate

The pressor response to intubation is known to be exaggerated in patients with gestational proteinuric hypertension (GPH). The effect of pretreatment with lignocaine 1.5 mg kg-1, magnesium sulphate 40 mg kg-1 or alfentanil 10 micrograms kg-1 on this pressor response was studied in 69 patients with moderate to severe GPH. Systolic arterial pressure exceeded baseline values for the first 5 min after tracheal intubation in the lignocaine group, with a peak increase of 31.6 (SEM 3.6) mm Hg at 2 min after intubation, but no mean increase in pressure occurred in the two other groups. Following intubation, six of 24 mothers in the alfentanil group, six of 21 in the lignocaine group and one of 24 in the magnesium group (P less than 0.05) exhibited a systolic arterial pressure (SAP) greater than 180 mm Hg sustained for 2 min or more. Alfentanil caused the least change in heart rate, but resulted in significant fetal depression.

Anaesthetic hazards of the 'passion gap'. A case report

Dental abnormalities cause problems for both dentist and anaesthetist. The anaesthetic hazards associated with the 'passion gap'--a term used in the western Cape Province for removal of the top four incisor teeth, a practice widespread among members of the Cape Coloured community--are discussed. Recommendations are made to assist the anaesthetist when dealing with such a patient.

Characteristics of a DNA probe (pa3'HVR) when used for paternity testing

DNA probes that detect polymorphic loci in the human genome are finding widespread application in many areas of genetic testing. Paternity testing represents one area for the application of probe technology; this report presents data obtained in a paternity testing program with a probe (pa3'HVR) derived from a locus (D16S85) approximately 8 kilobases (kb) downstream from the alpha globin gene complex on chromosome 16. The pa3'HVR probe used under stringent conditions of hybridization detects a highly polymorphic locus in chromosomal DNA digested with Pvu 2 restriction endonuclease. Alleles at the D16S85 locus were grouped into 58 size bins differing from one another by 100 base pairs in the black and white populations. The most common alleles detected in whites fell into the 2.3-kb group with a collective frequency of 0.1849. In blacks, the most common allele group is 2.0 kb with a collective frequency of 0.1333. The probe was used for restriction fragment length polymorphism mapping in conjunction with standard paternity testing techniques in 100 paternity cases. Thirty direct exclusions were encountered in the 100 cases with standard testing methods, versus 27 exclusions with the pa3'HVR probe alone. Four exclusions detected with standard methods were not detected with the probe and one exclusion detected with the probe was missed by standard testing. The probability of excluding a falsely accused man by use of the pa3'HVR probe was approximately 90 percent. In cases where exclusions were not encountered, the data obtained with the pa3'HVR probe increased the paternity index calculated from standard testing by about 16-fold.2+ informative for paternity testing.

Identification of the 37-kDa protein displaying a variable interaction with the erythroid cell membrane as glyceraldehyde-3-phosphate dehydrogenase

In previous studies from this laboratory we isolated and characterized a 37-kDa protein that was associated with the membrane of erythroid cells. The polypeptide appeared to undergo a lineage-specific alteration in its interaction with the membrane during erythroid development and migrated as a family of isoelectric focusing variants during analyses on two-dimensional gels. We report here that the 37-kDa protein is homologous to the enzyme glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12). This conclusion was reached from the results of several experimental approaches comparing the biochemical and genetic properties of the 37-kDa protein (p37) with authentic glyceraldehyde-3-phosphate dehydrogenase. Peptide maps of highly purified p37 and glyceraldehyde-3-phosphate dehydrogenase, generated with Staphylococcus V8 protease, were identical. The nucleotide sequence of a cDNA clone encoding p37 was nearly identical to the published sequence for genes encoding glyceraldehyde-3-phosphate dehydrogenase. These results suggest that the interaction of the enzyme with the red cell membrane is more complex than previously envisioned. The existence of subpopulations of glyceraldehyde-3-phosphate dehydrogenase molecules is envisioned that exhibit different levels of enzyme activity and bind to the red cell membrane with varying affinities.

Isolation and characterization of a 37,000-dalton protein associated with the erythrocyte membrane

We have purified a 37,000-dalton polypeptide (p37) from the red cell membrane that was found in previous studies to undergo a lineage-specific alteration in its membrane association. Our data suggest that p37 associates with the red cell membrane through electrostatic interactions that are resistant to 0.5 M NaCl or 10 mM EDTA. Conditions found to elute p37 from red cell ghosts include H2O at pH 12, 0.1 N NaOH + 1 mM ethanol and 1.0% Triton X-100. p37 was purified substantially from ghosts by Triton X-100 solubilization followed by sequential DEAE-Sephadex and CM-Sephadex chromatography. When p37 was analyzed by two-dimensional gel electrophoresis, a family of isoelectric focusing variants was detected ranging in pI from 7.0 to 7.8. All of the isoelectric focusing variants showed homology to one another when compared serologically with anti-p37 antibodies or by limited peptide mapping using Staphylococcus aureus V8 protease. The isoelectric focusing variants appear to represent distinct, yet related polypeptides rather than degrees of post-translational modifications to a single species, inasmuch as all of the variants are present in anti-p37 immunoprecipitates prepared from in vitro translations programmed with p37 mRNA.

Characterization of the processed form of a ubiquitous protein displaying a variable membrane organization in erythroid cells

We recently identified a group of proteins that are present in all hematopoietic cells but are organized in the cell membrane of erythrocytes in a lineage-specific fashion (Blood 61:803, 1983). One of these polypeptides has a mol wt of approximately 37,000 (p37T) when translated in vitro from messenger RNA (mRNA) extracted from the erythroleukemic K562 cell line. The membrane-associated form of the p37 translation product has been analyzed in detail here. When detergent lysates prepared from biosynthetically labeled K562 cells were reacted with an antiserum containing anti-p37T antibodies, one of the proteins immunoprecipitated had a nominal mol wt of 36,000 to 37,000 (p37M). Several results suggest that this protein is homologous to the p37 translation product: (1) the protein, like the mRNA coding for the p37 translation product, was expressed in cell lines with diverse differentiated phenotypes; (2) the antigenic determinant(s) on p37M and p37T are oriented to the inner surface of the erythrocyte membrane while being oriented to the outer surface of erythroleukemic cells; and (3) one-dimensional peptide maps show homology between p37M and p37T. P37M does not appear to possess an N-terminal leader sequence that is proteolytically cleaved as the molecule is inserted into the membrane. In addition, p37M is not glycosylated.

Quantitation of membrane glycoprotein IIIa on intact human platelets using the monoclonal antibody, AP-3

A murine monoclonal antibody specific for glycoprotein (GP)IIIa was prepared by immunization with a GPIIb- and GPIIIa-enriched Triton X-114 extract of platelet membranes. This antibody, designated AP-3, was shown by indirect immunoprecipitation to react solely with GPIIIa derived from either P1A1-positive or -negative individuals. The epitope on GPIIIa recognized by AP-3 is expressed on dissociated GPIIIa as well as on Ca+2-dependent complexes of GPIIb and GPIIIa, as shown by crossed immunoelectrophoresis in the presence or absence of EDTA. A previously described monoclonal antibody specific for the GPIIb/IIIa complex (AP-2) inhibited platelet aggregation induced by ADP, thrombin, collagen, or arachidonic acid (Pidard et al, J Biol Chem 258:12582-12586, 1983). In contrast, AP-3 had no effect on aggregation induced by any of these reagents, a finding similar to that previously reported for the GPIIb-specific monoclonal antibody, Tab (McEver et al, J Clin Invest 66:1311-1318, 1980). At saturation, 40,200 AP-3 molecules were bound per platelet, a value similar to that obtained for AP-2 or Tab. Thus, data derived using AP-3 indicate that significant amounts of free GPIIIa are not present, thereby supporting the hypothesis that GPIIb and GPIIIa exist complexed in a 1:1 stoichiometry in the plasma membrane of intact, nonactivated platelets.

Isolation and serological characterization of a monoclonal antibody recognizing the N blood group antigen

A mouse hybridoma has been isolated which secretes a hemagglutinating monoclonal antibody (MoAb) recognizing the N and 'N' blood group antigens. This conclusion is based upon the following observations. First, all red cells expressing either N or one of the alleles of Ss (ie, 'N' were strongly agglutinated by the MoAb diluted fourfold. The only cells not reactive were of the M+N-S-s-(U-) and M+N-S-s-(U+) phenotype and cells (J.R. and A.G.) expressing Lepore-type hybrids of the MN and Ss sialoglycoproteins, which do not express N or 'N'. Secondly, red cells of the N+S-s-(U-) phenotype were rendered unreactive to MoAb following treatment of the cells with trypsin, which is known to destroy N antigen activity. Conversely, cells expressing S and/or s maintained their reactivity with MoAb following trypsin treatment, which does not cleave 'N' from the Ss sialoglycoprotein. When spent culture medium containing MoAb was diluted and tested against a panel of red cells, the antibody titer fell into two distinct categories depending upon the MNSs phenotype of the target. Red cells expressing either homozygous or heterozygous N-sialoglycoprotein (N-SGP) were agglutinated by 128-fold diluted MoAb. In contrast, a 16-fold dilution of MoAb was the endpoint for agglutination of cells lacking N-SGP, but expressing S and/or s.

Reorientation of membrane polypeptides during erythrocyte maturation

Messenger RNA extracted from the erythroleukemic cell line K562 was translated in vitro and the translation products reacted with an antiserum raised against human erythrocyte ghosts. Polypeptides immunoprecipitated by the antiserum were characterized by SDS-polyacrylamide gel electrophoresis and fluorography. The antiserum immunoprecipitated polypeptides with nominal molecular weights of 37,000 (p37), 20,000 (p20), 19,000 (p19), 18,000 (p18), 14,000 (p14), 13,000 (p13), and 11,000 (p11) daltons. Since the antiserum was raised against antigenic determinants present on both the inner and outer surface of the red cell membrane, differential absorption of antiserum with intact red cells, or ghosts, was used to localize the translation products to the inner or outer membrane surface. Absorption was also used to determine if any of the immunoprecipitated translation products represented membrane markers for the erythroid lineage. Absorption of the antiserum with red cell ghosts removed all antibodies reacting with in vitro translation products. Absorption with intact cells from various lineages removed anti-p20 antibodies and did not absorb anti-p19 or anti-p18 antibodies. Absorption with intact cells from all lineages except mature erythrocytes absorbed anti-p37, anti-p14, and anti-p13 antibodies, suggesting that these antigens are expressed on the outer membrane surface. Mature erythrocytes were incapable of absorbing these antibody populations, suggesting a lineage-specific reorientation of these antigens in the membrane during erythropoiesis.

Characterization of antigens on human lymphocytes coded by messenger RNA translated in vitro

Translation and immunoprecipitation were used to identify messenger RNAs (mRNAs) coding for surface antigens expressed on human lymphoblastoid cells. The mRNAs were extracted from several human lymphoid cell lines as well as from fibroblastoid lines. These mRNAs were translated in vitro, and the translation products were reacted with xenoantisera raised against the antigens on human lymphoid cells. Products immunoprecipitated by these antisera were analysed by electrophoresis and fluorography. Four antisera immunoprecipitated a polypeptide with a mol. wt (MW) of approximately 32,000 (p32) from translations programmed with mRNA extracted from all the cell lines. Two antisera immunoprecipitated, in addition to p32, another polypeptide with a MW of approximately 25,000 (p25) only from translations programmed with RNA from lymphoid cell lines. p25 mRNA in the different lymphoid cell lines fell into three basic abundance classes as determined by in vitro translation and immunoprecipitation. Cells from two Burkitt's lymphomas (Raji and Daudi) did not express detectable p25 mRNA. Two T-lymphoblastoid lines (Molt-4 and 1301) contained five- to 10-fold less p25 mRNA than the B-lymphoid cell lines (Victor, RPMI-8866, RPMI-6410, RPMI-8226 and RPMI-1788). Both p32 and p25 were expressed on the cell surface inasmuch as lymphoblastoid cells adsorbed antibodies to both polypeptides. Human fibroblast, Raji or Daudi cells adsorbed anti-p32 antibodies from the antiserum but not anti-p25. Quantitative absorptions of the antiserum with T- or B-lymphoblastoid cells was used to determine the relative amounts of p32 and p25 expressed on the cell surface. B-lymphoblastoid cells were found to express two- to five-fold more p25 on the cell surface then T-lymphoblastoid cells. p25 does not represent an immunoglobulin light-chain precursor inasmuch as a 1000-fold excess of unlabeled human Ig did not compete with p25 translated in vitro for binding by its respective antibody.

Anti-RNP monoclonal antibodies derived from a mouse strain with lupus-like autoimmunity

systemic lupus erythematosus (SLE) and related rheumatic and connective-tissue diseases are often associated with the production of antibodies directed against a variety of specific cellular components. Recent evidence indicates that two such autoantigens, the Sm and RNP antigens recognized by SLE sera, exist in small ribonucleoprotein complexes found in the nuclei of higher eukaryotes. Studies of the structure and function of these autoantigenic particles with human sera used as probes have been limited because of the multiplicity of autoantibodies often found in an individual serum. Through this communication, we report that MRL/Mp-+/+ (MRL/n) mice, which spontaneously develop a disease exhibiting many of the characteristics of human SLE, possess anti-RNP antibodies in addition to anti-Sm and anti-DNA as previously reported. Spleen cells from one such autoimmune mouse were used to produce a stable hybridoma secreting antibodies that react simultaneously with a protein of Mr 40,000 and a doublet of approximately 70,000, a pattern of reactivity identical to and characteristic of human SLE anti-RNP autoantibodies.

Anti-RNP monoclonal antibodies derived from a mouse strain with lupus-like autoimmunity

systemic lupus erythematosus (SLE) and related rheumatic and connective-tissue diseases are often associated with the production of antibodies directed against a variety of specific cellular components. Recent evidence indicates that two such autoantigens, the Sm and RNP antigens recognized by SLE sera, exist in small ribonucleoprotein complexes found in the nuclei of higher eukaryotes. Studies of the structure and function of these autoantigenic particles with human sera used as probes have been limited because of the multiplicity of autoantibodies often found in an individual serum. Through this communication, we report that MRL/Mp-+/+ (MRL/n) mice, which spontaneously develop a disease exhibiting many of the characteristics of human SLE, possess anti-RNP antibodies in addition to anti-Sm and anti-DNA as previously reported. Spleen cells from one such autoimmune mouse were used to produce a stable hybridoma secreting antibodies that react simultaneously with a protein of Mr 40,000 and a doublet of approximately 70,000, a pattern of reactivity identical to and characteristic of human SLE anti-RNP autoantibodies.

Effectiveness of chest tube evacuation of pneumothorax in neonates

This is a retrospective review of the effectiveness of 149 chest tubes placed in attempts to evacuate 91 pneumothoraces among 57 infants. Forty-four percent of initial evacuation attempts were ineffective; 42% of total chest tubes throughout the clinical courses were ineffective. The largest number of these ineffective chest tubes lay posterior in the pleural cavity. Fifty-six percent of posterior tubes were ineffective whereas only 4% of anterior tubes were ineffective. Other causes for failure included tubes which had perforated the lung, diaphragm, or mediastinum or were lying subcutaneously. On some occasions, chest tubes were mistakenly used to evacuate intrathoracic air which was actually a pulmonary pseudocyst or pneumomediastinum. Two thoracostomy sites were chosen: the superior and lateral. Eighty-five percent of chest tubes inserted through the superior approach lay anteriorly in the pleural cavity whereas only 47% of the laterally inserted tubes lay anteriorly. Superior thoracostomy tubes were significantly more effective than lateral tubes because of their more frequent anterior location. There were also fewer complications with superior thoracostomy tubes. Whereas only 10% of superiorly inserted tubes encroached upon the mediastinum, 32% of lateral tubes did so. To be effective, chest tubes should be placed anteriorly in the pleural space; this location is more often achieved via the superior thoracostomy approach.

Antepartum diagnosis and intrapartum management of lethal renal defects

Bilateral renal agenesis (Potter syndrome) in the neonate is incompatible with life. Unfortunately, these infants are often delivered by cesarean section, as premature labor and breech presentation are commonly associated with the condition. In reviewing the obstetric course of 6 women who recently delivered such babies, the authors have found that antepartum diagnosis is possible in most cases. specifically, vaginal delivery should be strongly considered for patients in premature labor with intact membranes and breech presentation when there is ultrasound evidence of an abnormally shaped fetal head, absence of the fetal bladder, and severe oligohydramnios.

Fetal hydantoin syndrome, neuroblastoma, and hemorrhagic disease in a neonate

This is the first patient report of maternal ingestion of anticonvulsants associated with the triad of fetal hydantoin syndrome, neuroblastoma, and hemorrhagic disease. The neuroblastoma, a neural crest tumor, is the fourth of such origin reported after in utero exposure to phenytoin, suggesting that phenytoin is a transplacental carcinogen. Infants of epileptic mothers receiving anticonvulsants should be closely examined at birth for the fetal hydantoin syndrome and monitored for hemorrhagic problems. The neural crest tumor may be found at birth or later in childhood.