Pig genome analysis: differential distribution of SINE and LINE sequences is less pronounced than in the human and mouse genomes

The distribution of SINE and LINE sequences in the pig genome was examined by fluorescence in situ hybridization (FISH), interspersed repeat PCR, and restriction analysis of high molecular weight DNA. FISH revealed a largely uniform hybridization to the euchromatic chromosome regions with both interspersed repeats, although a bias toward the G-bands was observed for the LINE probe. Southern blots of inter-SINE and inter-LINE PCR products showed strong hybridization to LINE and SINE probes, respectively. High molecular weight DNA derived from a pig x hamster hybrid cell line was cut with a panel of G + C and A + T rich rare cutter restriction enzymes, then run on a pulsed field gel and Southern blotted. Sequential hybridization with SINE and LINE probes showed that SINE hybridization was to relatively low molecular weight fragments with the G + C rich enzymes, whereas the LINE probe gave hybridization to significantly larger fragments produced by these enzymes. DNA samples digested with A + T rich enzymes gave essentially similar patterns with SINE and LINE probes. We conclude that the pattern of differential distribution of SINEs and LINEs, which has been described in man and mouse, does exist in the pig but is much less pronounced.

Fast food arthritis--a clinico-pathologic study of post-Salmonella reactive arthritis

OBJECTIVE

To study the clinical presentation, immunogenetics, and serum immune response to lipopolysaccharide (LPS) in a cohort of patients with post-Salmonella reactive arthritis (ReA).

METHODS

A validate ReA screening questionnaire (Quest 2) was mailed to 919 individuals reporting symptoms of gastroenteritis to the health department after eating at a single restaurant. Three hundred twenty-one persons returned questionnaires; 170 reported symptoms outside the gastrointestinal tract; 23 of those 170 reporting persistent joint symptoms were seen 4 to 16 weeks after the outbreak and 5 of the 23 were seen in followup 12 to 20 weeks later. Clinical features, HLA Class I typing, serum soluble CD8 levels, and serum antibodies to gram negative LPS by ELISA were determined.

RESULTS

Joint complaints were reported more frequently by individuals with a longer duration of diarrhea. Upper extremity joints were frequently involved, and 66% reported one or more extraarticular symptoms of Reiter's syndrome. Three of 5 typed individuals were HLA-B27 positive, including 3 of the 4 most severely involved. Serum soluble CD8 levels correlated poorly with disease activity measured either clinically or by C-reactive protein. Antibodies to Klebsiella and Shigella LPS rose over time, while antibodies to Salmonella LPS fell.

CONCLUSION

The clinical picture of post-Salmonella ReA is less stereotyped than often assumed, although severity correlated with HLA-B27 status. The association of joint symptoms with duration of diarrhea and the kinetics of the anti-LPS antibody response support the hypothesis that abnormal gut permeability plays a role in the pathogenesis of post-Salmonella ReA.

Amino-acid substitutions in the cleavage site of acyl-coenzyme A:isopenicillin N acyltransferase from Penicillium chrysogenum: effect on proenzyme cleavage and activity

Site-directed mutagenesis of the penDE gene and expression in Escherichia coli has produced recombinant acylcoenzyme A:isopenicillin N acyltransferase (re-AT) containing amino-acid substitutions in the proenzyme cleavage site (decreases) region (Asp-Gly102 decreases Cys103-Thr-Thr). The effect of these substitutions on proenzyme cleavage and AT activity has been investigated. The re-AT with substitutions at Cys103 (Cys103-->Ser, Cys103-->Ala and Cys103-->Trp) were uncleaved and inactive. Substitutions at Asp101 and Gly102 (Asp101-->Gly, Gly102-->Ala, Gly102-->Val, Gly102-->Met, Gly102-->Val and Asp101Gly102-->GlyPhe) did not prevent proenzyme cleavage or abolish AT activity. Thr105-->Ser and Thr105-->Ala substitutions did not prevent proenzyme cleavage or AT activity; however, AT containing Thr105-->Val resulted in a significant inhibition of proenzyme cleavage.

The accuracy of duplex ultrasonography in the planning of skin flaps in the lower extremity

The septocutaneous perforators represent one of the major sources of the blood supply to the skin of the lower extremity. Despite several well-described anatomic accounts, the location of lower leg septocutaneous perforators, as they originate from each of the three main infrapopliteal vessels in the leg, remains inconsistent as a result of individual anatomic variations. With the aid of duplex ultrasonography (color Doppler imaging), preoperative, mapping and size determination of these perforators can be provided. The skin paddle can then be designed to lie exactly over these perforators, ensuring blood supply to the skin paddle. The location and distribution of medial septocutaneous perforators in the leg, which originate from the posterior tibial artery, were mapped using anatomic dissections (29 lower extremities). These findings were then compared with duplex ultrasonographic data in 9 living volunteers (18 lower extremities). The medial septocutaneous perforators were chosen for this study because they course directly over the posterior tibial artery, making their location difficult to assess with standard Doppler techniques. The hand-held Doppler is incapable of distinguishing flow originating from the perforators versus the posterior tibial artery. No significant difference existed between cadaver and duplex distributions. "Large" perforator vessels (> 1 mm outer diameter) were evenly distributed with a central tendency at 140 to 150 mm from the medial malleolus. The distribution of "small" perforator vessels (< 1 mm outer diameter) was skewed. Fifty percent were found within 80 mm of the medial malleolus and the remainder spread proximally in the leg.(ABSTRACT TRUNCATED AT 250 WORDS)

A rapid test for infectious and inflammatory enteritis

BACKGROUND

Inflammatory illnesses are an indication for specific diagnostic studies and possible antimicrobial therapy. The presence of fecal leukocytes has been used as a marker of inflammatory diarrhea; however, microscopic examination of the fecal smear is unreliable if the specimen is transported, refrigerated, frozen, or collected by swab.

OBJECTIVE

To evaluate a rapid, sensitive, semiquantitative test for detection of fecal leukocytes using antilactoferrin latex bead agglutination (LFLA), a test that remains sensitive even after specimens are refrigerated, frozen, or stored on swabs.

METHODS

LFLA titers were determined in stool specimens from previously healthy volunteers before and after experimental infection with different enteric pathogens and from patients with nosocomial diarrhea caused by Clostridium difficile.

RESULTS

Healthy controls and subjects with noninflammatory diarrhea caused by Vibrio cholerae consistently demonstrated LFLA titers less than 1:50. In contrast, subjects with inflammatory diarrhea caused by Shigella species and C difficile had markedly elevated titers. Titers for subjects with experimental shigellosis ranged from 1:50 to 1:3200, with seven (78%) of nine at 1:400 or greater. Titers for patients with C difficile enteritis ranged as high as 1:1200, with six (50%) of 12 at 1:400 or greater. Subjects with experimental enteropathogenic Escherichia coli infection also had elevated titers, ranging from 1:100 to 1:1600, with three (43%) of seven at 1:400 or greater. Titers for subjects with experimental enterotoxigenic E coli infection were moderately elevated, with nine (53%) of 17 ranging from 1:50 to 1:200 (only one [6%] of 17 was > or = 1:400), suggesting a mild inflammatory process.

CONCLUSIONS

The fecal LFLA assay distinguishes inflammatory from noninflammatory diarrhea, may provide new information on mildly inflammatory processes, and may be a useful, rapid test in a diagnostic algorithm for acute, infectious diarrheal illnesses.

Substance abuse: the role of depression and trauma--a case report

Substance abuse is associated diagnostically with existing depression, pathological mourning of the traumatic event itself, with the inevitable experience of object loss, and loss of love. Inability to form object representation insures primitive lack of object constancy, resulting in pre-oedipal longing and neediness and malignant affect. Ambivalence towards the sadistic love objective is recognized and allows for a healthier, more complete period of mourning (Freud, 1917). Indeed, depression is banished from family acknowledgement in the service of homeostatic denial. This only reinforces the identified patient's feeling of unreality, shame and guilt over verbalizing the depression and the frequent underlying traumatic history. The enormous role of socio-economic stress is pervasive, yet the focus here is on individuals with complex dynamic constellations which are often ignored in the face of external factors. Addiction as attempt to self-medicate depression and trauma remains the overarching theme.

Use of porcine interspersed repeat sequences in PCR-mediated genotyping

PCR primers derived from porcine short and long interspersed repeat sequences were used to amplify DNA samples isolated from individual members of three-generation pig reference pedigrees. Subsequent high-resolution gel electrophoresis of both SINE and LINE-PCR products allowed direct visualisation of polymorphisms that segregated in a Mendelian manner. Additional polymorphisms were detected by Southern blotting of the gels described above followed by hybridization with simple sequence DNA. Genotyping by interspersed repeat-PCR exploits the natural architecture of the pig genome and allows the typing of polymorphisms by utilizing pre-existing sequence information.

Serine 228 is essential for catalytic activities of 85-kDa cytosolic phospholipase A2

The Ca(2+)-sensitive cytosolic phospholipase A2 (cPLA2) displays both a phospholipase A2 and a lysophospholipase activity. Numerous hydrolases, including lipases, catalyze the hydrolysis of ester bonds by means of an active site triad of amino acids that includes a serine or a cysteine residue. We have examined whether human cPLA2 belongs to this class of enzymes by using site-directed mutagenesis. Although chemical inactivation of cPLA2 by the sulfhydryl reagent N-ethylmaleimide made it appear that cysteine(s) may be essential for catalysis, all 9 cysteine residues of cPLA2 proved dispensable, allowing near-normal enzyme activity when substituted by alanine. We noted that cPLA2 contains a 110-amino-acid region with sequence homology to phospholipase B (PLB) from Penicillium notatum. Interestingly, one of the conserved serines of cPLA2, Ser-228, within this domain aligns with the lipase consensus sequence Gly-X(Leu)-Ser(137)-X(Gly)-Gly of PLB. Replacement of Ser-228 by alanine (or threonine or cysteine) yielded catalytically inactive cPLA2, even though the native conformation was maintained as determined by CD spectroscopy. Likewise, the lysophospholipase activity was completely abolished by the Ser-228 mutations. In contrast, substitution by alanine of three different serines of cPLA2 (Ser-195, Ser-215, or Ser-577) that also aligned with the PLB sequence allowed for substantial enzymatic activity of cPLA2. Our findings provide evidence that 1) Ser-228 participates in the catalytic mechanism of cPLA2 and that 2) both the phospholipase A2 and the lysophospholipase activities of cPLA2 are catalyzed by the same active site residue(s).

Acyl-coenzyme A: isopenicillin N acyltransferase from Penicillium chrysogenum: effect of amino acid substitutions at Ser227, Ser230 and Ser309 on proenzyme cleavage and activity

Using a high level Escherichia coli expression system for the Penicillium chrysogenum penDE gene, we have produced acyl-coenzyme A: isopenicillin N acyltransferase (AT) enzymes containing amino acid substitutions at three conserved Ser residues. Chosen for study based on amino acid sequence homologies to other proteins, Ser227, Ser230 and Ser309 were changed to Cys or Ala to assess amino acid side chain involvement in proenzyme cleavage and AT enzyme mechanism. Substitutions at Ser230 had no effect on proenzyme cleavage, acyl-coenzyme A: IPN acyltransferase (IAT) or acyl-coenzyme A:6-aminopenicillanic acid acyltransferase (AAT) activities. While Ser227-->Cys had no effect, Ser227-->Ala produced uncleaved proenzyme lacking both AAT and IAT activities, suggesting that the presence of a nucleophilic side chain at this residue is required for proenzyme cleavage and AT activity. Substitution of Ser309-->Cys did not appreciably prevent proenzyme cleavage, IAT or AAT activity. Recombinant AT (recAT) proenzyme containing Ser309-->Ala was cleaved; however, IAT and AAT activities were not observed. This separation of proenzyme cleavage from IAT and AAT activities has not been previously observed, and suggests that Ser309 is involved in substrate acylation.

Characterization by electrospray mass spectrometry of human Ca(2+)-sensitive cytosolic phospholipase A2 produced in baculovirus-infected insect cells

The 85-kD cytosolic phospholipase A2 (cPLA2) is a novel receptor-regulated phospholipase that is thought to initiate the production of inflammatory lipid mediators. Since cPLA2 is present only in minute amounts (less than 0.01% of total cellular protein) in various cells and tissues, we have used the baculovirus expression system to produce sufficient quantities of cPLA2 for structural and functional analysis. The cDNA for cPLA2 was cloned into a baculovirus expression vector and, upon infection of Spodoptera frugiperda Sf-21 cells with the recombinant virus, cPLA2 was produced at high levels (9% of total cellular soluble protein). Gel electrophoresis and immunoblot analysis demonstrated that the recombinant protein has properties indistinguishable from cPLA2 present in human monocytic U937 cells. Structural analysis of recombinant cPLA2, using electrospray mass spectrometry in conjunction with automated sequence analysis, confirmed the expected sequence and revealed two post-translational modifications of the protein, phosphorylation on at least one site, and acetylation of the N-terminal serine residue after removal of the initiating methionine. In spite of the presence of six potential N-glycosylation sites, there is no evidence that any of them is glycosylated. The baculovirus expression system should prove useful for production of cPLA2, and electrospray mass spectrometry is a rapid and accurate method for the analysis of post-translational modifications.

Botulinum toxin for the treatment of spasticity in multiple sclerosis. New observations

Potential advantages of intramuscular botulinum toxin for the treatment of spasticity include the lack of sensory effects, ability to target specific muscle groups, ability to weaken muscles in a graded fashion and absence of caustic chemicals such as phenol. We describe the use of botulinum toxin for the treatment of severe lower extremity spasticity in two subjects with multiple sclerosis. Both subjects showed an improvement in spasticity, as measured by the modified Ashworth scale, and in functional status. Both subjects exhibited reductions in muscle tone not only in injected muscles, but also in noninjected muscles in the region. These more distant clinical effects have not been emphasized in previous studies after therapeutic injections of botulinum toxin. Further research is needed to clarify the cause and prevalence of these regional motor effects, as well as to further examine the safety and efficacy of botulinum toxin for spasticity treatment.

The requirement for subunit interaction in the production of Penicillium chrysogenum acyl-coenzyme A:isopenicillin N acyltransferase in Escherichia coli

Subunit interaction in the formation of active acyl-coenzyme A:isopenicillin N acyltransferase (AT) has been investigated. Various AT derivatives were produced from altered Penicillium chrysogenum penDE genes placed in Escherichia coli expression systems. The regions of penDE encoding the alpha (11 kDa) and beta (29 kDa) AT subunits were separated at the DNA level by linker insertion at the region encoding Gly102/Cys103. Synthesis of AT from the resulting two-cistron mRNA resulted in active alpha,beta-heterodimeric recombinant AT (reAT), containing subunits of 11 and 29 kDa (similar to wild-type AT). Complete separation of the alpha and beta subunits was performed by placing the region of penDE encoding each subunit on different plasmids. Production of either subunit in the absence of the other did not form active reAT. However, cotransformation of E. coli with two plasmids, each encoding a different AT subunit, produced reAT having acyl-coenzyme A:6-aminopenicillanic acid (acyl-CoA:6-APA) AT activity. Mutation of penDE replacing Thr105 with Asn resulted in inactive and uncleaved reAT. Coexpression of this mutant penDE with a penDE derivative encoding the beta subunit in E. coli produced acyl-CoA:6-APA AT activity. These results suggest that the formation of reAT involves cooperative folding events between the subunits. In vitro transcription/translation was used to determine the origin of the AT hydrolase activity that cleaves the 40-kDa precursor polypeptide. The appearance of a 29-kDa protein (and presumably the corresponding 11-kDa protein, although not observable) from the 40-kDa in vitro translated protein provides further evidence that AT hydrolysis is an autocatalytic event.

Synteny mapping in the horse using horse-mouse heterohybridomas

In a study of 35 horse-mouse heterohybridoma cell lines, synteny in the horse was found between LDHB, PEPB and IGF1 and between NP, MPI and IDH2. A synteny between ADA and PEPC was also indicated. The loci for horse immunoglobulin light chain (IgL) genes and for LDHA were independent.

Neonatal mortality following transfusion of red cells with high plasma potassium levels

The death of a neonatal infant following cardiac surgery and the transfusion of packed red cells (RBCs) with high plasma potassium levels is reported. The patient had been diagnosed at 2 weeks of age as having multiple cardiac malformations. During cardiopulmonary bypass surgery, multiple units of packed RBCs less than 5 days old were transfused. In response to a "stat" order and after depletion of stock units prepared for neonatal usage, a 32-day-old unit of packed RBCs was issued for transfusion. After approximately 60 mL was rapidly transfused from this unit, the patient experienced cardiac arrest. Serum potassium concentration after transfusion and before death was 8.9 mmol per L. Plasma potassium concentration in the remainder of the transfused packed RBC unit was approximately 60 mmol per L. A model was created to calculate the posttransfusion plasma potassium concentration, and close correlation was found between the model and the observed potassium concentration, which assumes that the potassium load had not yet been distributed to the extravascular and intracellular fluid compartments. It is concluded that the transfusion of relatively large volumes of RBCs be limited to fresh packed RBCs or to packed RBCs that have been saline washed, to minimize the complications of electrolyte disturbances.

Designing for the future

The American Organization of Nurse Executives (AONE) is the national organization of nurse executives and nurse managers. AONE provides leadership, professional development, advocacy, and research to advance nursing practice and patient care, promote nursing leadership excellence, and shape healthcare public policy. This column, written by officers and executive staff members of AONE, raises issues and discusses trends of importance to nursing administrators.

In vitro and in vivo pharmacological characterization of N6-cyclopentyl-9-methyladenine (N-0840): a selective, orally active A1 adenosine receptor antagonist

The pharmacological and biochemical profile of N6-cyclopentyl-9-methyladenine (N-0840) was elucidated in vitro and in vivo. In radioligand binding assays, N-0840 had 14- to 400-fold greater affinity for A1 than A2 adenosine receptors and did not inhibit radioligand binding to alpha-1, alpha-2, beta, 5-hydroxytryptamine 1a, muscarinic, D1 or D2 receptors at concentrations < or = 10,000 nM. In guinea pig tissues, N-0840 competitively antagonized A1 receptor-mediated, 5'-N-ethylcarboxamidoadenosine-induced negative inotropism (paced left atria, KB = 0.83 microM), chronotropism (spontaneously beating right atria, KB = 0.91 microM) and dromotropism (Langendorff heart; KB = 0.72 microM). However, at concentrations up to 100 microM, N-0840 did not antagonize A2 adenosine receptor-mediated, 5'-N-ethylcarboxamidoadenosine-induced relaxations of the guinea pig aorta. N-0840 was a poor inhibitor of total cyclic nucleotide phosphodiesterase activity and of adenosine uptake (IC50 > 200 microM), and it did not inhibit adenosine deaminase activity. In anesthetized rats, N-0840 selectively antagonized A1 adenosine receptor-mediated bradycardia, but generally failed to affect A2 adenosine receptor-mediated vasodilation in the in situ perfused hindquarters (A2/A1 selectivity: > or = 33-fold). The duration of action of N-0840 ranged from 1 min (after 3 mumol/kg i.v.) to 8 hr (after 100 mumol/kg p.o.). N-0840 (< or = 100 mumol/kg i.v.; < or = 1,000 mumol/kg p.o.) had little or no effect on blood pressure or heart rate and produced no adverse drug reactions.(ABSTRACT TRUNCATED AT 250 WORDS)

SCH 45752--an inhibitor of calmodulin-sensitive cyclic nucleotide phosphodiesterase activity

A highly potent inhibitor of calmodulin-sensitive phosphodiesterase (PDE) activity was isolated from the culture broth of an unidentified fungal isolate, SCF-125. A chemically defined medium was developed for production of this compound. The PDE inhibitor was isolated from the fermentation filtrate by adsorption on a macro-reticular resin and further purified by gel filtration chromatography and reverse-phase HPLC. The major PDE inhibitor was identified as cephalochromin, a bis-naphthopyrone, by spectral data analysis. The compound, SCH 45752, inhibited calmodulin-sensitive PDE activities with IC50 values of 40-47 nM. It inhibited the activities of calmodulin-independent PDE and various protein kinases with higher IC50 values (2-40 microM). SCH 45752 does not appear to be a calmodulin antagonist. Furthermore, SCH 45752 affects smooth muscle contraction at a concentration of 30 microM; it potentiated the relaxing effect of sodium nitroprusside on carotid artery media contracted by histamine. Thus SCH 45752 is one of the most potent inhibitors of calmodulin-sensitive PDE activity known, and it is capable of exerting a pharmacological effect in at least one intact tissue model.

A chromosomal basis for the differential organization of a porcine centromere-specific repeat

Digestion of porcine DNA with the restriction enzymes SnoI and BamHI and subsequent gel electrophoresis revealed the presence of a repeat fragment of approximately 340 bp in length. When this fragment was cloned and used to probe a Southern blot containing pig DNA that had been digested with various enzymes, a ladder pattern of bands based on a unit of 340 bp was observed. Three individual BamHI repeat units were sequenced; each monomer unit was approximately 90% identical in sequence to the other two monomers. Double digestion did not alter the ladder pattern, indicating a differential distribution of restriction enzyme sites within the repeat family. We demonstrate by Southern blotting of DNAs from a panel of pig x rodent hybrid cell lines that the differential restriction site distribution has a chromosomal basis. We show that this repeat family hybridizes to the centromeres of all pig chromosomes other than the Y chromosome. However, when stringency was raised, hybridization persisted only to certain metacentric chromosomes.

5' and 3' SINE-PCR allows genotyping of pig families without cloning and sequencing steps

A microsatellite-containing clone, isolated from a pig Chromosome (Chr) 1-specific library was characterized by sequencing and computer analysis. The (CA)17 microsatellite motif was located at the 3' end of a short interspersed element (SINE) sequence at the position normally occupied by the oligo (A) stretch. Further computer analysis indicated that 12% of published pig SINE sequences contain dinucleotide repeat motifs adjacent to their 3' ends. By performing PCR with a single SINE primer in combination with a panel of arbitrarily selected unique primers, we have demonstrated that, as in human, polymorphisms can be detected and typed in pig family DNAs. A large number of SINE primer x unique primer combinations have been screened for the ability to detect polymorphisms in pig reference family DNAs. This approach does not require prior sequence information other than that of the pig SINE. We have also found polymorphisms at the 5' ends of pig SINE sequences by similar methods, but with a primer facing out to the 5' end of the SINE.

Anti-sulfatide antibodies in neurological disease: binding to rat dorsal root ganglia neurons

Increased titers of anti-sulfatide antibodies were detected by ELISA in 5 of 200 patients and control subjects. All 5 patients had sensory impairment; 4 had neuropathy, and one had multiple sclerosis. Of the patients with neuropathy, 2 had a clinical syndrome of small fiber sensory neuropathy with normal electrophysiological or nerve biopsy studies, 1 had a sensorimotor axonal neuropathy associated with IgM monoclonal gammopathy, and 1 had sensorimotor neuropathy with multifocal motor conduction block and anti-GM1 antibodies. The anti-sulfatide antibodies bound to the surface of unfixed rat dorsal root ganglia neurons and human neuroblastoma cells, and to fixed sections of central and peripheral myelin. No binding was detected following intraneural injection into rat sciatic nerves. Pre-absorption with sulfatide but not with galactocerebroside eliminated the tissue binding activity. These findings indicate that increased titers of anti-sulfatide antibodies are found in patients with sensory impairment but are not restricted to a particular neurological syndrome or type of neuropathy. The significance of anti-sulfatide antibodies is uncertain although sulfatide on dorsal root ganglia neurons may be a target antigen.

The psychosocial aspects of rehabilitation

Physical therapy is not only about the healing of the body; ramifications to the patient's and family's emotional and social lives also must be considered. The following case examples from Wellmark Healthcare Services, Inc. exemplify the positive results of addressing psychosocial issues in rehabilitation.

Progressive multifocal leukoencephalopathy in patients with human immunodeficiency virus

Lesions of progressive multifocal leukoencephalopathy (PML) in patients infected with the human immunodeficiency virus (HIV) often have mononuclear cell infiltrates so intense that they obscure the nature of the lesion. This response may be especially prominent in stereotactic biopsies of contrast-enhancing areas. Of 10 consecutive PML lesions biopsied stereotactically, three were markedly, two were moderately, and five were mildly inflamed. There were few to no enlarged oligodendrocytic nuclei with inclusions in the markedly and moderately inflamed lesions. We investigated all biopsies with immunoperoxidase, DNA in situ hybridization, polymerase chain reaction, and Southern immunoblot methodologies for toxoplasmosis and the following viruses: JC, cytomegalovirus, herpes simplex viruses I and II, and human T-cell lymphotropic viruses I, II, and III. We confirmed the presence of JC virus in each lesion; polymerase chain reaction revealed HIV genome only in one. Inflammatory PML lesions in HIV+ patients do not reflect co-infection with toxoplasmosis or viruses commonly seen in these patients. The mononuclear cells are primarily T lymphocytes. Patients with severely inflamed PML lesions, whether HIV+ or not, often show stabilization of symptoms with or without antiviral treatment and have longer lengths of survival than patients with less inflamed lesions.

A chromosome 1-specific DNA library from the domestic pig (Sus scrofa domestica)

Chromosomes were prepared from lymphocytes of a male domestic pig and flow-sorted on a dual-laser FACS. Twenty spots were observed, corresponding to the known pig karyotype of 18 pairs of autosomes plus the X and Y. DNA was isolated from 10,000 copies of the presumed chromosome 1 spot, restricted with Sau3A, ligated into the vector pGEM4z, and PCR amplified using universal primers; the products were then re-ligated into pUC18. After transformation into Escherichia coli, 210,000 independent colonies were obtained, 5% of which contained only vector DNA. The average insert size of the library was 405 bp. Southern blotting revealed that 36% of the clones contained single-copy DNA and that the remainder contained moderately or highly repetitive DNA. Screening with a (CA)n probe revealed that roughly 1% of the clones contained microsatellite sequences. A bulk insert of the library was biotinylated by PCR and used as a probe for chromosomal in situ suppression hybridization to pig chromosomes, which confirmed that the library is specific for chromosome 1. However, sequences from the centromeric and telomeric regions seem to be underrepresented in the library.

Synteny mapping of the bovine IGHG2, CRC and IGF1 genes

A panel of bovine-murine hybrid cell lines was analysed for 10 loci, including three (IGF1, IGHG2 and the calcium release channel gene [CRC]) that have previously been mapped in man, but not in cattle. The IGF and CRC genes were indirectly mapped to chromosomes 5 and 18 respectively and the syntenies of the HOX2 and GH genes and of the NP and FOS genes were confirmed. The results also show that the IGHG2 locus, which is linked to NP and FOS on human chromosome 14, is separated from these genes in cattle. By showing synteny of the IGHG2 and MPI loci, the IGHG2 locus has been indirectly mapped to chromosome 21.

Mapping of repetitive bovine DNA sequences on cattle Y chromosomes

Three male-specific PCR products of the sequences BC1.2, lambda ES6.0, and BRY.1 were used as probes for Southern blot analyses. Each of these probes generated a complex male-specific band pattern, which showed some quantitative variations among bulls. Hybridization patterns obtained with the BC1.2 and lambda ES6.0 PCR products were interrelated. Chromosomal locations of these repeats were determined by hybridizing the tritiated PCR products in situ to male metaphase spreads. The BC1.2 and lambda ES6.0 PCR products hybridized to Yp13-->p12, whereas the BRY.1 PCR product hybridized over the entire Y chromosome. In addition, the BC1.2 and lambda ES6.0 PCR products hybridized to the distal half of the acrocentric Y chromosome of Bos indicus, indicating that the short arm of the B. taurus Y chromosome is homologous with the telomeric end of the B. indicus Y and supporting the notion that the Y chromosomes of these two species differ by a pericentric inversion.

Multidisciplinary home rehabilitation. A practical model

The home is the most natural setting for rehabilitation. At home, the patient and family become active team members and the plan of care is created and carried out in the environment in which the patient will live. Home rehabilitation enhances the patient's autonomy, independence, and community reintegration.

Localization of the lysine epsilon-aminotransferase (lat) and delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase (pcbAB) genes from Streptomyces clavuligerus and production of lysine epsilon-aminotransferase activity in Escherichia coli

Lysine epsilon-aminotransferase (LAT) in the beta-lactam-producing actinomycetes is considered to be the first step in the antibiotic biosynthetic pathway. Cloning of restriction fragments from Streptomyces clavuligerus, a beta-lactam producer, into Streptomyces lividans, a nonproducer that lacks LAT activity, led to the production of LAT in the host. DNA sequencing of restriction fragments containing the putative lat gene revealed a single open reading frame encoding a polypeptide with an approximately Mr 49,000. Expression of this coding sequence in Escherichia coli led to the production of LAT activity. Hence, LAT activity in S. clavuligerus is derived from a single polypeptide. A second open reading frame began immediately downstream from lat. Comparison of this partial sequence with the sequences of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D valine (ACV) synthetases from Penicillium chrysogenum and Cephalosporium acremonium and with nonribosomal peptide synthetases (gramicidin S and tyrocidine synthetases) found similarities among the open reading frames. Since mapping of the putative N and C termini of S. clavuligerus pcbAB suggests that the coding region occupies approximately 12 kbp and codes for a polypeptide related in size to the fungal ACV synthetases, the molecular characterization of the beta-lactam biosynthetic cluster between pcbC and cefE (approximately 25 kbp) is nearly complete.

A sequence motif found in a Drosophila heterochromatin protein is conserved in animals and plants

Modifiers of position-effect-variegation in Drosophila encode proteins that are thought to modify chromatin, rendering it heritably changed in its expressibility. In an attempt to identify similar modifier genes in other species we have utilized a known sequence homology, termed chromo box, between a suppressor of position-effect-variegation, Heterochromatin protein 1 (HP1), and a repressor of homeotic genes, Polycomb (Pc). A PCR generated probe encompassing the HP1 chromo box was used to clone full-length murine cDNAs that contain conserved chromo box motifs. Sequence comparisons, in situ hybridization experiments, and RNA Northern blot analysis suggest that the murine and human sequences presented in this report are homologues of the Drosophila HP1 gene. Chromo box sequences can also be detected in other animal species, and in plants, predicting a strongly conserved structural role for the peptide encoded by this sequence. We propose that epigenetic (yet heritable) changes in gene expressibility, characteristic of chromosomal imprinting phenomena, can largely be explained by the action of such modifier genes. The evolutionary conservation of the chromo box motif now enables the isolation and study of putative modifier genes in those animal and plant species where chromosomal imprinting has been described.

Ventilator dependency: decision-making, daily functioning and quality of life for patients with Duchenne muscular dystrophy

Ventilator assistance is offered to patients with Duchenne muscular dystrophy as an option to extend life. This paper discusses the effect of respiratory difficulties and the subsequent quality of life for 17 patients and 14 family members living in the community. Areas covered included decision-making, health, education, vocational and recreational status, community resources and life satisfaction. Activity levels before and after ventilator use were assessed. Despite restrictions in daily life both before and after ventilator use, quality of life was fairly good. Restrictions in daily life were caused by a combination of progression of the disease and the ventilator, and family members were more burdened by the ventilator than were patients. It is concluded that patients and their families should make the decision about accepting or rejecting assisted ventilation.

Molecular characterization of the acyl-coenzyme A:isopenicillin N acyltransferase gene (penDE) from Penicillium chrysogenum and Aspergillus nidulans and activity of recombinant enzyme in Escherichia coli

The final step in the biosynthesis of beta-lactam antibiotics in Penicillium chrysogenum and Aspergillus nidulans involves removal of the L-alpha-aminoadipyl side chain from isopenicillin N (IPN) and exchange with a nonpolar side chain. The enzyme catalyzing this reaction, acyl-coenzyme A:isopenicillin N acyltransferase (acyltransferase), was purified from P. chrysogenum and A. nidulans. Based on NH2-terminal amino acid sequence information, the acyltransferase gene (penDE) from P. chrysogenum and A. nidulans were cloned. In both organisms, penDE was located immediately downstream from the isopenicillin N synthetase gene (pcbC) and consisted of four exons encoding an enzyme of 357 amino acids (approximately 40 kilodaltons [kDa]). The DNA coding sequences showed approximately 73% identity, while the amino acid sequences were approximately 76% identical. Noncoding DNA regions (including the region between pcbC and penDE) were not conserved. Acyltransferase activity from Escherichia coli producing the 40-kDa protein accepted either 6-aminopenicillanic acid or IPN as the substrate and made a penicillinase-sensitive antibiotic in the presence of phenylacetyl coenzyme A. Therefore, a single gene is responsible for converting IPN to penicillin G. The active form of the enzyme may result from processing of the 40-kDa monomeric precursor to a heterodimer containing subunits of 11 and 29 kDa.

The beta-lactam biosynthesis genes for isopenicillin N epimerase and deacetoxycephalosporin C synthetase are expressed from a single transcript in Streptomyces clavuligerus

Isopenicillin N isomerase (epimerase) has been purified from Streptomyces clavuligerus, and the amino acid sequence of the N-terminus has been determined. By using single oligonucleotide probes based on high GC codon bias ("guessmers"), the translation start codons were determined for two successive genes in the beta-lactam-biosynthetic pathway and mapped within a 3.6-kilobase-pair KpnI restriction fragment. The epimerase gene (cefD) was located immediately upstream of the deacetoxycephalosporin C synthetase (expandase) gene (cefE) that was characterized previously. cefD was sequenced and expressed in Escherichia coli; the resulting cell extracts contained epimerase activity. Western immunoblots demonstrated that a protein comigrated with purified S. clavuligerus epimerase at 44 kilodaltons. cefD and cefE were separated by an 81-base-pair segment. The DNA sequence upstream of the epimerase gene had a high AT content, suggestive of a promoter region. Primer extension analysis of S. clavuligerus mRNA showed that the start of transcription occurred approximately 130 base pairs upstream of the epimerase translation start site; Northern (RNA blot) analysis revealed a hybridization signal large enough to code for both epimerase and expandase, and nuclease S1 protection assays showed that a single message may code for epimerase, expandase, and another unknown protein. When cefD and cefE were placed in an expression vector, concomitant synthesis of both epimerase and expandase occurred in E. coli.

B cell small lymphocytic lymphoma and chronic lymphocytic leukemia with peripheral neuropathy: two cases with neuropathological findings and lymphocyte marker analysis

Two patients with lymphoproliferative disorders developed peripheral neuropathy and neoplastic lymphocytic nerve infiltrates. One of these patients, with B cell small lymphocytic lymphoma, presented with a chronic axonal neuropathy. CD22+, CD5- cells were identified in the epineurium. The other patient with chronic lymphocytic leukemia of 3 years duration developed a mixed axonal and demyelinating neuropathy. CD22+ and CD5+ cells were observed in the endoneurium. While the cause of the neuropathy in these two cases is unknown, intraneural or systemic autoantibody production may have led to the development of disease.

Motor neuron disease and amyotrophic lateral sclerosis: relation of high CSF protein content to paraproteinemia and clinical syndromes

From 1984 to 1988, 11 of 120 patients (9%) with motor neuron disease (MND) had paraproteins detected by serum immunofixation electrophoresis (IFE), compared with 4 (3%) by cellulose acetate gels: 1 patient had progressive spinal muscular atrophy, 5 patients had amyotrophic lateral sclerosis (ALS), and 5 patients had ALS with probable upper motor neuron signs. Four of 5 patients (80%) with cerebrospinal fluid (CSF) protein content above 75 mg/dl had paraproteins, as did 6 of 30 with values above 50 mg/dl. Four of 14 patients with cerebrospinal oligoclonal bands (OCB) also had paraproteins. Two patients with ALS, CSF protein content above 75 mg/dl, and paraproteinemia had lymphoma. We conclude the following about patients with MND: high CSF protein content (especially above 75 mg/dl) or CSF OCB makes paraproteinemia more likely; some of these patients may have lymphoma; there is an inordinately high occurrence of paraproteinemia in MND; and IFE on agarose is more sensitive than electrophoresis on cellulose acetate in detecting paraproteins. Syndromes of paraproteinemia and high CSF protein are not restricted to the lower motor neuron but qualify as "ALS" with coexisting upper motor neuron signs.

Isolation and characterization of two male-specific DNA fragments from the bovine gene

Two independent male-specific DNA fragments were isolated from the bovine genome by the technique of cloning by deletion enrichment. Each is represented in the order of one to five copies per haploid genome. Neither fragment was found to be polymorphic between two individuals of different breeds with 12 different restriction enzymes. A 'zoo blot' demonstrated that one fragment had a closely related sequence in the sheep genome, although no other hybridizing sequences were detected in a variety of animal DNAs tested with both probes. The DNA sequence of each fragment is presented; one fragment has a continuous open reading frame and a potential Z-DNA forming region.

A dental Class III malocclusion treated to a full-cusp Class II molar relationship

A case report of a Class III dental malocclusion superimposed on a straight skeletal pattern is presented. The patient was a 14-year-old girl with limited growth potential. This case included congenitally missing maxillary permanent lateral incisors, impacted maxillary permanent canines, and bilateral posterior open bites. The patient's soft-tissue profile was normally convex. In addition to her malocclusion, the patient had a history of difficulty breathing through the nose. The general treatment included palatal expansion, protraction headgear, and comprehensive edgewise orthodontic therapy.

Lead absorption in indoor firing range users

To determine if users of indoor firing ranges may be at risk from lead exposure, we studied a law enforcement trainee class during three months of firearms instruction. Blood lead levels were obtained before training and at four-week intervals during training. Air lead levels were measured three times during instruction. Blood lead levels rose from a pre-training mean of 0.31 mumol/L to 2.47 mumol/L. Mean air lead levels were above 2,000 micrograms/m3, more than 40 times the Occupational Safety and Health Administration's standard of 50 micrograms/m3. Cumulative exposure to lead and the change in blood lead were positively correlated. Control measures need to be studied to determine their efficacy in decreasing or eliminating this health risk.

Aerosol optical depth determination from ground based irradiance ratios

The atmospheric optical depth serves as an input parameter to atmospheric correction procedures in remote sensing and as an index of atmospheric opacity or constituent columnar abundance for meteorological applications. Its measurement, typically performed by means of a small field of view radiometer centered on the solar disk, is sensitive to the absolute calibration accuracy of the instrument. In this paper a simple technique is presented which permits the extraction of aerosol optical depth from the ratio of total to direct irradiance measurements. An error analysis performed on the results of radiative transfer simulations and field measurements indicates that the technique generates values of aerosol optical depth which are sufficiently accurate for many applications. This method thus represents a useful alternative to standard sunphotometer measurements.

Cloning and characterization of beta-lactam biosynthetic genes

Seven genes coding for two different enzymes of the penicillin/cephalosporin biosynthetic pathway have been cloned from fungal and bacterial sources. Using amino acid sequences derived from the purified enzymes, oligonucleotide probes were designed to hybridize to their cognate genes in a genomic library. The high degree of similarity (57%) between enzymes of bacterial and fungal origin suggests a horizontal transfer of a primordial beta-lactam pathway, probably from a bacterial cell to a fungal cell. Overproduction of the proteins in Escherichia coli has allowed further study of the mechanism of action of these important enzymes.

High-frequency percussive ventilation compared with conventional mechanical ventilation

In seven patients with severe respiratory distress, conventional mechanical ventilation and PEEP were used initially for respiratory support, which was changed to high-frequency percussive ventilation (HFPV) at the same level of airway pressure and FIO2. During both modes of ventilation, patients could breathe spontaneously via a low-threshold demand valve. With HFPV, PaO2 improved significantly (p less than .01) compared with PaO2 during conventional methods. Cardiac output was unaffected by the change to HFPV.

Cloning, characterization, and expression in Escherichia coli of the Streptomyces clavuligerus gene encoding deacetoxycephalosporin C synthetase

Biosynthesis of cephalosporin antibiotics involves an expansion of the five-membered thiazolidine ring of penicillin N to the six-membered dihydrothiazine ring of deacetoxycephalosporin C by a deacetoxycephalosporin C synthetase (DAOCS) enzyme activity. Hydroxylation of deacetoxycephalosporin C to form deacetylcephalosporin C by a deacetylcephalosporin C synthetase (DACS) activity is the next step in biosynthesis of cephalosporins. In Cephalosporium acremonium, both of these catalytic activities are exhibited by a bifunctional enzyme, DAOCS-DACS, encoded by a single gene, cefEF. In Streptomyces clavuligerus, separable enzymes, DAOCS (expandase) and DACS (hydroxylase), catalyze these respective reactions. We have cloned, sequenced, and expressed in E. coli an S. clavuligerus gene, designated cefE, which encodes DAOCS but not DACS. The deduced amino acid sequence of DAOCS from S. clavuligerus (calculated Mr of 34,519) shows marked similarity (approximately 57%) to the deduced sequence of DAOCS-DACS from C. acremonium; however, the latter sequence is longer by 21 amino acid residues.

Replacements of lysine 32 in yeast cytochrome c. Effects on the binding and reactivity with physiological partners

Lysine 32 has been previously implicated by chemical modification and modeling studies as a key component of the domain which controls recognition and binding of cytochrome c to its physiological partners, e.g. cytochrome b2, cytochrome c peroxidase, and cytochrome oxidase. In order to quantitate the importance of this residue, we have investigated the role of Lys-32 in the reactivity of cytochrome c in redox reactions in vitro and in vivo with protein partners by using a series of altered forms of iso-1-cytochrome c from the yeast Saccharomyces cerevisiae in which Lys-32 is replaced by Leu-32, Gln-32, Trp-32, and Tyr-32. Leu-32 and Gln-32 represent substitutions which change charge without seriously affecting the steric bulk of the side chain or the stability of the protein. For the Leu-32- and Gln-32-altered proteins, steady state kinetic studies with cytochrome c peroxidase, cytochrome b2, and cytochrome oxidase showed that neither of the steady state kinetic parameters, Km nor Vmax, were substantially modified by mutation. Studies of single turnover kinetics with a small molecule (ascorbate) or within bound complexes with either cytochrome b5 or cytochrome c peroxidase demonstrated that redox kinetics are only slightly affected by these substitutions. NMR experiments demonstrated that the Gln-32-altered protein can still bind strongly to a physiological partner, cytochrome c peroxidase. Growth in lactate medium demonstrated that the activity in vivo compared with the normal value was reduced to only 85% with the Gln-32- and Leu-32-altered proteins and to 65% with the Trp-32- and Tyr-32-altered proteins. These findings suggest that the evolutionary invariance of Lys-32 reflects only small quantitative changes in the binding and reactivity of cytochrome c.