Using time- and size-resolved particulate data to quantify indoor penetration and deposition behavior

Because people spend approximately 85-90% of their time indoors, it is widely recognized that a significant portion of total personal exposures to ambient particles occurs in indoor environments. Although penetration efficiencies and deposition rates regulate indoor exposures to ambient particles, few data exist on the levels or variability of these infiltration parameters, in particular for time- and size-resolved data. To investigate ambient particle infiltration, a comprehensive particle characterization study was conducted in nine nonsmoking homes in the metropolitan Boston area. Continuous indoor and outdoor PM2.5 and size distribution measurements were made in each of the study homes over weeklong periods. Data for nighttime, nonsource periods were used to quantify infiltration factors for PM2.5 as well as for 17 discrete particle size intervals between 0.02 and 10 microns. Infiltration factors for PM2.5 exhibited large intra- and interhome variability, which was attributed to seasonal effects and home dynamics. As expected, minimum infiltration factors were observed for ultrafine and coarse particles. A physical-statistical model was used to estimate size-specific penetration efficiencies and deposition rates for these study homes. Our data show that the penetration efficiency depends on particle size as well as home characteristics. These results provide new insight on the protective role of the building shell in reducing indoor exposures to ambient particles, especially for tighter (e.g., winterized) homes and for particles with diameters greater than 1 micron.

Fate of linear alkylbenzenes released to the coastal environment near Boston Harbor

Linear alkylbenzenes (LABs) were used to assess the fates of hydrophobic organic compounds (HOCs) released to a large urban harbor and the adjoining offshore waters. We found that particulate concentrations of the individual C12 LAB isomers in 1996 summertime surface waters decreased from 1 pM in Boston Harbor to 20-200 fM in coastal Massachusetts and Cape Cod Bays. Levels fell to only a few fM in offshore Gulf of Maine locations. These observations were consistent with municipal wastewater in Boston Harbor as the predominant input followed by dispersal via known circulation patterns in this region. Phase-dependent removal rate coefficients for flushing, vertical scavenging, volatilization, photodegradation, and biodegradation of individual LAB isomers were constrained from literature, field observations, and laboratory experiments and combined with estimates of wastewater release rates into a predictive 3-box model. Vertical scavenging, biodegradation, and flushing were predicted to be the most important fate processes for C12 LABs in the Boston Harbor-MA Bay-Cape Cod Bay flow system with about 1% of the harbor releases "surviving" passage. For HOCs such as the relatively bio-recalcitrant LAB, 6-phenyldodecane, it appears that we are at present able to predict the coastal fate of harbor-introduced HOCs in this system within a factor of 2. Contrary to expectations from biodegradation experiments, the ratio of internal-to-external (I/E) LAB isomers decreased offshore in both water and sediment samples, suggesting we are "missing" an important process affecting LAB fates.

Sinonasal disease in patients with sarcoidosis

Sarcoidosis is a chronic granulomatous disease of unclear etiology with a propensity to involve the lower respiratory tract, but may also involve the upper respiratory tract. Histologically, it is characterized by non-caseating granulomas of various organ systems. Although nasal and sinus involvement is uncommon, patients with sarcoidosis presenting with nasal and sinus complaints may have sinonasal sarcoidosis or simply rhinosinusitis. We reviewed the cases of six patients with pulmonary sarcoidosis who developed chronic sinonasal disease. All six patients had intranasal findings consistent with sinonasal sarcoidosis, but only four had histologic evidence of sinonasal sarcoidosis. These four patients continue to require extensive therapy including topical steroids, systemic steroids, intralesional steroid injections, and nasal irrigations. We conclude that patients with histologically proven sinonasal sarcoidosis present a significant therapeutic challenge because their symptoms and physical findings are often persistent despite aggressive medical and surgical therapy. Their recalcitrant sinonasal disease is thought to result from the destruction of cilia and mucus-producing glands by the granulomatous process.

Laryngotracheal reconstruction in canines: fixation of autologous costochondral grafts using polylactic and polyglycolic acid miniplates

OBJECTIVE

To examine the feasibility of a new method of laryngotracheal reconstruction (LTR) that uses a bioabsorbable plating system consisting of polylactic and polyglycolic acid and provides some advantages over currently used methods.

DESIGN AND INTERVENTIONS

Anterior subglottic stenosis was created in 10 beagles that then underwent LTR using an autologous costochondral graft. External laryngotracheal framework and cartilage grafts were secured using a sheet and screws made from a copolymer composed of polylactic and polyglycolic acid. Animals were humanely killed at 40, 60, and 90 days, and specimens were submitted for pathological examination. Histologic analysis included evaluation for inflammatory reaction, polylactic and polyglycolic acid incorporation into cartilage, cartilage necrosis, cartilage remodeling, and graft epithelialization.

RESULTS

All animals underwent LTR after creation of a subglottic stenosis without episodes of airway compromise. After LTR, all airways were returned to prestenosis diameter without significant complication, and all animals were immediately extubated after surgery without difficulty. After the animals were killed, distraction of the stenotic cricoid area was demonstrated in 100% of the cases. Significant necrosis was noted in 2 of 10 grafts grossly; however, histologic analysis demonstrated significant areas of viable cartilage, areas of cartilage remodeling, and good epithelialization despite graft necrosis. Complete epithelialization of grafts was noted in the other 8 specimens.

CONCLUSIONS

Using a canine model, we demonstrated a bioabsorbable plating system that offers an effective method for LTR. This model has the advantages of providing external support to the operated laryngeal and tracheal framework, elimination of the difficulties of suture placement, and potential future failure while offering rigid external fixation of a cartilage graft.

Photo amidoglycosylation of an allal azidoformate. Synthesis of beta-2-amido allopyranosides

[figure: see text] Photolysis of an allal C-3 azidoformate provoked intramolecular nitrene insertion into the glycal C=C unit and allowed direct incorporation of alcohol nucleophiles as beta-disposed substituents at C-1. The 2-amido allopyranoside products were elaborated via N-acylation and selective oxazolidinone hydrolysis, providing N-Boc-protected 2-amino sugars and simplifying stereochemical assignments. Synthesis of the potentially labile allal azidoformate was achieved via reaction of the corresponding carbonyl imidazolide with trimethylsilyl azide, facilitated by dibutyltin oxide.

Factorial invariance for combined Wechsler Adult Intelligence Scale-Revised and Wechsler Memory Scale-Revised scores in a sample of clients with alcohol dependency

This study examined the joint factor structure of the WAIS-R and WMS-R in a sample of 289 participants (mostly males) with alcohol dependency. In a confirmatory phase we contrasted a range of factor models derived from previous analyses of the Wechsler scales. The best fitting model incorporated five factors representing Verbal Comprehension, Perceptual Organization, Attention-Concentration, Verbal Memory, and Visual Memory, with reassignment of factor loadings for two subtests. The invariance of the measurement model was then examined comparing data from a large sample of healthy participants (J. R. Carstairs & E. A. Shores, 1999). The results indicated that the number of factors was invariant across samples, and four of the factors satisfied the criterion of partial measurement invariance.

Characterization of indoor particle sources using continuous mass and size monitors

A comprehensive indoor particle characterization study was conducted in nine Boston-area homes in 1998 in order to characterize sources of PM in indoor environments. State-of-the-art sampling methodologies were used to obtain continuous PM2.5 concentration and size distribution particulate data for both indoor and outdoor air. Study homes, five of which were sampled during two seasons, were monitored over week-long periods. Among other data collected during the extensive monitoring efforts were 24-hr elemental/organic carbon (EC/OC) particulate data as well as semi-continuous air exchange rates and time-activity information. This rich data set shows that indoor particle events tend to be brief, intermittent, and highly variable, thus requiring the use of continuous instrumentation for their characterization. In addition to dramatically increasing indoor PM2.5 concentrations, these data demonstrate that indoor particle events can significantly alter the size distribution and composition of indoor particles. Source event data demonstrate that the impacts of indoor activities are especially pronounced in the ultrafine (da < or = 0.1 micron) and coarse (2.5 < or = da < or = 10 microns) modes. Among the sources of ultrafine particles characterized in this study are indoor ozone/terpene reactions. Furthermore, EC/OC data suggest that organic carbon is a major constituent of particles emitted during indoor source events. Whether exposures to indoor-generated particles, particularly from large short-term peak events, may be associated with adverse health effects will become clearer when biological mechanisms are better known.

Evaluation of a commercial PCR kit for diagnosis of cytomegalovirus infection of the central nervous system

We evaluated the AMPLICOR cytomegalovirus (CMV) PCR kit for the diagnosis of neurologic CMV infections on 43 positive and 112 negative archived cerebrospinal fluid specimens originally tested by an in-house PCR method. The AMPLICOR kit showed sensitivity and specificity of 95 and 100%, respectively, versus the home-grown assay, indicating its utility in this clinical setting.

Detection of cytomegalovirus in plasma and cerebrospinal fluid specimens from human immunodeficiency virus-infected patients by the AMPLICOR CMV test

We have developed the AMPLICOR CMV Test, which is rapid and sensitive for the detection of cytomegalovirus (CMV) in plasma and cerebrospinal fluid (CSF) specimens. The test incorporated an internal control in the reaction mixture to monitor the amplification efficiency and the presence of inhibitors. The AMPLICOR CMV Test was very specific in detecting 12 clinical CMV isolates and four laboratory CMV strains tested. Cross-reactivity with 26 non-CMV pathogens was not observed. The AMPLICOR CMV Test requires only 50 microl of specimen (plasma or CSF) for processing. The performance of the AMPLICOR CMV Test was compared to those of the CMV antigenemia assay and the conventional tube culture method. Among 112 plasma specimens from 43 human immunodeficiency virus-infected patients, CMV was detected in 20 (18%) of the specimens by the AMPLICOR CMV Test, 21 (19%) of the specimens by the CMV antigenemia assay, and 10 (9%) of the specimens by culture. In CSF specimens from AIDS patients, CMV was detected in 10 of 58 (17%) specimens tested by the AMPLICOR CMV Test, 5 of 28 (18%) specimens tested by the antigen assay, and none of the 25 specimens tested by culture. While the performance of the AMPLICOR CMV Test in this study was comparable to that of the CMV antigen assay, processing of specimens by the AMPLICOR CMV Test was much simpler than that by the antigen assay; in addition, the antigen assay requires greater than 10(5) leukocytes from blood or 1 ml of CSF to perform the assay. Our study suggested that the AMPLICOR CMV Test could provide a rapid and sensitive assay for the detection of CMV in plasma and CSF specimens.

A linkage map of sweet cherry based on RAPD analysis of a microspore-derived callus culture population

A partial linkage map was constructed for the sweet cherry (Prunus avium L.) cultivar Emperor Francis from a population of 56 microspore-derived callus culture individuals. The callus cultures were genotyped for two allozymes and 90 random amplified polymorphic DNA (RAPD) markers using 79 random decanucleotide DNA primers and the polymerase chain reaction (PCR). Eighty-nine markers mapped to 10 linkage groups totaling 503.3 cM. DNA blot and hybridization analysis using five cloned RAPDs as probes demonstrated that one of the decanucleotide primers amplified a region of the Emperor Francis genome containing a unique sequence, whereas the other four decanucleotide primers amplified regions of the Emperor Francis genome containing repeated sequences. The five cloned RAPD probes also recognized putative homologous regions in ground cherry, P.fruticosa Pall., and sour cherry, P. cerasus L., a naturally occurring allopolyploid between P.fruticosa and P.avium.

Herpes simplex type 2 in a patient with Mollaret's meningitis: demonstration by polymerase chain reaction

We describe a patient with recurrent self-limited aseptic meningitis meeting the criteria for Mollaret's syndrome, in whom extensive serological investigation and cerebrospinal fluid analysis failed to reveal a specific cause. Using polymerase chain reaction techniques to amplify herpes simplex viral DNA, we were able to identify the presence of herpes simplex virus type 2 in the cerebrospinal fluid. The duration of clinical illness may have been shortened by treatment with intravenous acyclovir. We suggest that herpes simplex virus may be a more common cause of aseptic meningitis than has been demonstrated by current commonly available serological and culture techniques.

Sequence analysis of arcelin 2, a lectin-like plant protein

The nucleotide sequence of the cDNA clone encoding arcelin 2 (Arc2), one member of a family of closely related lectin-like plant toxins from wild bean accession, is presented. The sequence contains a 265-amino acid (aa) open reading frame and is 99.3% homologous to Arc1, another of the four electrophoretic variants with proven antibiosis characters. These two proteins differ by four aa residues. Based on cross hybridizations of RNAs, it is assumed that Arc4 is more divergent than Arc1 and Arc2. Furthermore, it is likely that at least three of the variants are polypeptides of similar size and the observed molecular weight differences between them are due to differences in the number of glycosylation sites.

Cloning, characterisation and regulation of an alpha-amylase gene from Streptomyces venezuelae

The alpha-amylase gene (aml) of Streptomyces venezuelae ATCC15068 was cloned in Streptomyces lividans TK24 using the plasmid vector pIJ702. Sub-cloning and exonuclease III deletion experiments localised the sequences required for alpha-amylase production to a segment of 2.05 kb. Low-resolution nuclease S1 mapping revealed a aml transcript of approx. 1.7 kb, and the extracellular form of alpha-amylase was estimated by SDS-polyacrylamide gel electrophoresis to be 59 kDa, suggesting that aml mRNA is monocistronic. The nucleotide sequence of aml was determined and high-resolution nuclease S1 mapping experiments identified transcripts that appeared to initiate at a promoter identical to that of the alpha-amylase gene of Streptomyces limosus [Long et al., J. Bacteriol. 169 (1987) 5745-5754]. Transcription of aml in S. venezuelae, and of the cloned gene in Streptomyces coelicolor A3(2), was induced by maltose and repressed by glucose. Glucose repression in S. coelicolor A3(2) depended on a functional glucose kinase gene. The predicted amino acid sequence of the extracellular enzyme was very similar (75% identity) to the alpha-amylase of S. limosus and shared with this enzyme a strong susceptibility to tendamistat, a potent inhibitor of mammalian alpha-amylases. Sequence inspection revealed a putative signal sequence of 28 amino acids that preceded the probable signal peptidase cleavage site.

Molecular cloning of two types of GAP complementary DNA from human placenta

The ras p21 GTPase-activating protein (GAP) was purified from human placental tissue. Internal amino acid sequence was obtained from this 120,000-dalton protein and, by means of this sequence, two types of complementary DNA clones were isolated and characterized. One type encoded GAP with a predicted molecular mass of 116,000 daltons and 96% identity with bovine GAP. The messenger RNA of this GAP was detected in human lung, brain, liver, leukocytes, and placenta. The second type appeared to be generated by a differential splicing mechanism and encoded a novel form of GAP with a predicted molecular mass of 100,400 daltons. This protein lacks the hydrophobic amino terminus characteristic of the larger species, but retains GAP activity. The messenger RNA of this type was abundantly expressed in placenta and in several human cell lines, but not in adult tissues.

Analysis of HLA-DP allelic sequence polymorphism using the in vitro enzymatic DNA amplification of DP-alpha and DP-beta loci

Allelic sequence variation of the HLA DP-alpha and DP-beta genes has been analyzed in a panel of 34 DP-typed cell lines. The polymorphic second exon of these genes was specifically amplified in vitro by the polymerase chain reaction method, using the thermostable DNA polymerase of Thermus, aquaticus. The analysis of M13 clones containing the amplified DP-beta sequences revealed a total of 14 allelic variants. In general, specific allelic DP-beta sequences were associated with each of the defined DPw1-w6 types, with beta allele subtypes revealed for the DPw2 and DPw4 specificities. An additional six DP-beta alleles which did not correlate with any of the T cell-defined specificities (DP "blanks") were also identified. Only the two previously characterized alleles of DP-alpha were detected. These observations suggest that the T cell-defined DP specificities are determined by polymorphic residues on the beta-chain. The sequence polymorphisms in DP-beta are clustered in a few specific regions, and can be detected using sequence-specific oligonucleotide probes and polymerase chain reaction amplified DNA in a rapid dot-blot format. This approach provides a simple and informative method of DP typing. The DP-beta sequences derived from four DP-typed celiac disease patients were compared with the distribution of DP-beta alleles in control individuals.

Analysis of HLA-DP allelic sequence polymorphism using the in vitro enzymatic DNA amplification of DP-alpha and DP-beta loci

Allelic sequence variation of the HLA DP-alpha and DP-beta genes has been analyzed in a panel of 34 DP-typed cell lines. The polymorphic second exon of these genes was specifically amplified in vitro by the polymerase chain reaction method, using the thermostable DNA polymerase of Thermus, aquaticus. The analysis of M13 clones containing the amplified DP-beta sequences revealed a total of 14 allelic variants. In general, specific allelic DP-beta sequences were associated with each of the defined DPw1-w6 types, with beta allele subtypes revealed for the DPw2 and DPw4 specificities. An additional six DP-beta alleles which did not correlate with any of the T cell-defined specificities (DP "blanks") were also identified. Only the two previously characterized alleles of DP-alpha were detected. These observations suggest that the T cell-defined DP specificities are determined by polymorphic residues on the beta-chain. The sequence polymorphisms in DP-beta are clustered in a few specific regions, and can be detected using sequence-specific oligonucleotide probes and polymerase chain reaction amplified DNA in a rapid dot-blot format. This approach provides a simple and informative method of DP typing. The DP-beta sequences derived from four DP-typed celiac disease patients were compared with the distribution of DP-beta alleles in control individuals.

Allelic sequence variation of the HLA-DQ loci: relationship to serology and to insulin-dependent diabetes susceptibility

Analysis of sequence variation in the polymorphic second exon of the major histocompatibility complex genes HLA-DQ alpha and -DQ beta has revealed 8 allelic variants at the alpha locus and 13 variants at the beta locus. Correlation of sequence variation with serologic typing suggests that the DQw2, DQw3, and DQ(blank) types are determined by the DQ beta subunit, while the DQw1 specificity is determined by DQ alpha. The nature of the amino acid at position 57 in the DQ beta subunit is correlated with susceptibility to insulin-dependent diabetes mellitus. This region of the DQ beta chain contains shared peptides with Epstein-Barr virus and rubella virus.

Sequence analysis of the HLA-DR beta and HLA-DQ beta loci from three Pemphigus vulgaris patients

Pemphigus vulgaris (PV) is an autoimmune dermatologic disease that has been associated with the HLA serotypes DR4 and DRw6. In studying this association at the level of coding sequence polymorphism, we have determined the nucleotide sequences of the second variable exons from the HLA-DR beta and DQ beta loci from three PV patients with the HLA serotypes DR4/4, DR4/5, and DR4/5. These exons were enzymatically amplified by polymerase chain reaction (PCR) and cloned directly into an M13 vector for DNA sequencing. Analyses of amino acid sequences translated from the nucleotide sequence data show that all three patients contained a DR4 DR beta I sequence associated with the Dw10 DR4 subtype specificity, a relatively rare subtype among U.S. Caucasian DR4 haplotypes. The DQ beta sequence from three of the four DR4 haplotypes was identical to the sequence (DQB3.2) found on 60-80% of control DR4 haplotypes. These observations suggest that the amino acid residues at position 68, 69, and 72 of the DR beta I chain that distinguish Dw10 from the other DR4 subtypes may be involved in disease susceptibility.

Sequence analysis of HLA class II genes from insulin-dependent diabetic individuals

To examine the nature of HLA-linked genetic susceptibility to insulin-dependent diabetes mellitus (IDDM), we compared HLA class II gene sequences from IDDM patients and control individuals. Genomic libraries were constructed from two siblings with IDDM, typed serologically as DR3,w6 and DR3,4. These libraries represent the HLA haplotypes (DR3, DR4) most frequently associated with IDDM, as well as one haplotype found less often. Individual genomic clones were identified and assigned to specific loci and haplotypes. The nucleotide sequence was then determined from the variable second exon from the HLA-DQ alpha, DQ beta, and DR beta genes from all three haplotypes. Sequence variation within the DQ alpha genes could not be correlated with the disease. For all three haplotypes, the DQ alpha sequence from the IDDM patient was identical to the DR-matched control sequence. Similarly, for the DR3 haplotype, the DQ beta sequences matched all control DR3 alleles. The DQ beta sequence from the DR4 haplotype was identical to the predominant DR4 allele (DQ beta 3.2) but differed at four amino acid residues from the other major DR4 DQ beta sequence (DQ beta 3.1) found rarely among IDDM patients. Sequence analysis of the DQ beta gene from the DRw6 haplotype revealed a new allele that differed from the DQ beta allele from a control DR6 allele at two residues. The DR beta genes from these three haplotypes also did not show any sequence features uniquely associated with IDDM, although the frequency of certain allelic variants in all three of these haplotypes may be altered in the IDDM population. A particular group of amino acids was found to be shared between the DR beta-1 alleles from the DR4 and DRw6 haplotypes and may be involved in genetic susceptibility to IDDM.

alpha-Amylase gene of Streptomyces limosus: nucleotide sequence, expression motifs, and amino acid sequence homology to mammalian and invertebrate alpha-amylases

The nucleotide sequence of the coding and regulatory regions of the alpha-amylase gene (aml) of Streptomyces limosus was determined. High-resolution S1 mapping was used to locate the 5' end of the transcript and demonstrated that the gene is transcribed from a unique promoter. The predicted amino acid sequence has considerable identity to mammalian and invertebrate alpha-amylases, but not to those of plant, fungal, or eubacterial origin. Consistent with this is the susceptibility of the enzyme to an inhibitor of mammalian alpha-amylases. The amino-terminal sequence of the extracellular enzyme was determined, revealing the presence of a typical signal peptide preceding the mature form of the alpha-amylase.

Using work simulation to treat adults with back injuries

Occupational therapy at the Liberty Mutual Medical Service Center, Boston, Massachusetts, offers a diverse variety of modalities for the treatment of patients with low back pain. Treatment may include the use of a balance monitor, a multiwork station, a pneumatic lifting-lowering device, a computerized upper extremity work simulator, and a truck-driving simulator. The primary objective of occupational therapy in this setting is to provide a supportive environment where patients can practice and improve the execution of the work-related activities they need to perform their jobs while they are learning to live with or control their symptoms.

Alternative model for chromatin organization of the Saccharomyces cerevisiae chromosomal DNA plasmid TRP1 RI circle (YARp1)

TRP1 RI circle (now designated YARp1, yeast acentric ring plasmid 1) is a 1,453-base-pair artificial plasmid composed exclusively of Saccharomyces cerevisiae chromosomal DNA. It contains both the TRP1 gene and ARS1 (a DNA sequence that permits extrachromosomal maintenance of recombinant plasmids). This high-copy-number, relatively stable plasmid was shown to be organized into nucleosomes comparable to typical yeast chromatin, containing a possible maximum of nine nucleosomes per circle. Therefore, YARp1 can be used to examine the structure of chromatin of both a chromosomally derived replicator and a functional gene. By mapping regions of micrococcal nuclease cleavage in chromatin versus purified DNA, we located the positions of protected regions on the circle with reference to six unique restriction sites. Measurements made on patterns of early digestion products indicated that a region of approximately 300 base pairs in the vicinity of ARS1 was strongly resistant to micrococcal nuclease. The remainder of the plasmid appeared to be associated with five positioned nucleosomes and two nonnucleosomal, partially protected regions on the bulk of the molecules. After similar extents of digestion, naked DNA did not exhibit an equivalent pattern, although some hypersensitive cleavage sites matched sites found in the chromatin. These results are consistent with the interpretation that the protected domains are aligned with respect to a specific site or sites on the small circular chromatin.