Two cases of barotrauma associated with transtracheal jet ventilation

Two patients suffered barotrauma whilst undergoing transtracheal jet ventilation (TTJV). In the first, TTJV was provided by a Sanders injector and in the second it was given by a high frequency jet ventilator. Barotrauma was a consequence of the expiratory pathway becoming blocked. The mechanism of barotrauma and a method of airway pressure monitoring during TTJV are discussed. It is recommended that meticulous care is taken to ensure an adequate path for expiration when jet ventilation is used.

Sulfur-rich proteins of Chlamydia trachomatis: developmentally regulated transcription of polycistronic mRNA from tandem promoters

RNA was extracted at various times from cells infected with Chlamydia trachomatis serovar L1. Northern-blot analysis showed that transcription of the CrP gene encoding the 60-kDa cysteine-rich outer membrane protein (CrP) produces a temporally controlled polycistronic mRNA. Primer extension analysis indicated the presence of tandem promoters separated by 66 nt with transcriptional start points (tsp) located 577 and 643 nt upstream from the start codon of the mature 60-kDa CrP. Nucleotide (nt) sequencing of this region revealed a small open reading frame (SORF) with coding potential for an 88-amino acid protein containing 13 cysteine residues. This SORF is transcribed as both a polycistronic 2300-nt mRNA together with the CrP gene, and as a separate 480-nt mRNA. Analysis of the upstream sequences, around the tsp for these mRNAs, revealed the presence of three inverted repeat structures that might act as binding domain(s) for a regulatory protein.

Capital management balances charitable, financial goals

Effective capital management allows not-for-profit healthcare organizations to make investment decisions that fulfill their missions and meet financial goals. The process involves identifying components of the hospital's value and creating policies aimed at maximizing it; determining the hospital's ability to produce financial capital; and developing a process for allocating this financial capability among the components of value. Once this is completed, hospitals should determine criteria that balance charitable and financial goals, enabling them to pursue sound investments.

Correlation of infertility with altered tubal morphology and function in mice with salpingitis induced by a human genital-tract isolate of Chlamydia trachomatis

Progesterone-treated C3H mice were inoculated into the uterus or ovarian bursa with a human genital tract isolate of C. trachomatis (serovar E), or with control medium alone. The mice were then observed at various times up to 260 days after inoculation. Before being killed the mice were given pituitary gonadotrophins to induce ovulation. Eggs were sought in the oviducts and ciliary activity in the fimbrial and ampullary sections of the oviducts was determined by light microscopy, before detailed examination by scanning electron microscopy. Eggs were visible in all control oviducts and both mucosal ultrastructure and ciliary activity appeared normal. By contrast, eggs were not recovered from the inoculated oviducts of mice infected intrabursally, nor was ciliary activity observed up to 28 days after inoculation. After this, ciliary activity reappeared but eggs were still not transported to the oviduct. Ultrastructural studies suggested that severe mucus congestion accompanied by tubal oedema and loss of ciliated epithelia play a major role in the aetiology of chlamydial-induced tubal damage. Infertility following chlamydial salpingitis could be associated with failure of egg transportation to the oviduct. Egg transport was still impaired even when luminal ciliary activity, ultrastructural integrity and patency had recovered. Our results suggest that chlamydial salpingitis in this mouse model closely resembles the human disease in its pathology and consequences for fertility, making the model particularly relevant for research on chlamydial vaccine development.

Chlamydia trachomatis 60 kDa cysteine rich outer membrane protein: sequence homology between trachoma and LGV biovars

An 820 bp AccI-PstI fragment of the 60 kDa cysteine rich outer membrane protein (CrP) gene from C. trachomatis serovar L1 was used as a probe to locate the 60 kDa CrP gene of a recent serovar B trachoma isolate (Jali 20/OT). The probe hybridized to a single 1.8 kb SpeI fragment in Southern blot analyses of different restriction endonuclease digests of C. trachomatis serovar B DNA. This fragment was ligated into Lambda Zap II arms and Bluescript SK(-) recombinants, released by infection with the helper phage R408, were used as template for DNA sequence determination. Sequence analysis demonstrated a very high level of homology between the Jali 20/OT 60 kDa CrP and the previously published serovar L1 60 kDa CrP with only 8 out of 507 amino acid substitutions between the two proteins.

Analysis of the household distribution of trachoma in a Gambian village using a Monte Carlo simulation procedure

Studies on the household distribution of trachoma have reached conflicting conclusions. This paper describes a cross-sectional survey of endemic trachoma in a Gambian village. Cases of active trachoma were mapped, and the compound and household distribution of the disease analysed by a Monte Carlo simulation procedure which takes into account differences in the size and age distribution within individual households. Significant clustering of active trachoma cases both by village compound (p less than 0.0001) and bedroom (less than 0.05) were detected supporting the concept that intra-familial transmission of trachoma is important. There was no evidence of spatial clustering of rooms with higher than expected prevalence of trachoma. Clustering of disease in space or time provides important evidence of infectious aetiology and route of transmission. The methods discussed here are generally applicable in the study of other infectious diseases.

Surface-exposed epitopes on the major outer-membrane protein of Chlamydia trachomatis defined with peptide antisera

The surface exposure of computer-predicted, linear B-cell epitopes on the major outer-membrane protein (MOMP) of Chlamydia trachomatis serovar B was assessed using antibodies raised against synthetic peptides in conjunction with immunogold transmission electron microscopy. Several of the chosen peptides elicited antibodies which reacted with both denatured and native MOMP. The majority of the exposed epitopes were found within the variable segments of MOMP. For each of the epitopes identified, the extent of their surface accessibility varied both among individual organisms and different developmental forms. Evidence for two distinct subspecies-specific epitopes within VS4 is presented.

The major outer membrane protein of Chlamydia trachomatis: critical binding site and conformation determine the specificity of antibody binding to viable chlamydiae

The major outer membrane protein (MOMP) is the prime candidate for the development of a chlamydial vaccine. Antibodies to the subspecies-specific epitope neutralize chlamydial infection. Monoclonal antibodies (MAbs) to this epitope were prepared either by immunization with whole chlamydiae or with a 16 amino acid synthetic peptide. The critical binding site on the subspecies epitope for these MAbs was determined to single amino acid resolution using several hundred solid-phase peptides. A frame shift of just one amino acid in critical binding site completely prevented antibody binding to viable chlamydiae. A single MAb to whole organisms was capable of spanning both the surface-exposed, conformation-dependent, subspecies epitope and a buried, conformation-independent species epitope some 10 A distant. Immunization with peptide generated an MAb with reduced binding constraints which permitted the antibody to bind with broadened species-specificity at the subspecies binding site. The results show for the first time the importance of both critical binding site and conformation at the subspecies epitope. We suggest that the conformational flexibility of short, epitopic peptide vaccines may in some cases be advantageous, giving rise to extended specificity not attained with the natural protein.

Molecular cloning and sequence analysis of a developmentally regulated cysteine-rich outer membrane protein from Chlamydia trachomatis

Two overlapping genomic fragments have been cloned from Chlamydia trachomatis serovar L1 DNA. Sequence determination of 2530 bp has revealed two open reading frames coding for 'cysteine-rich' (Cr) proteins. One of these proteins was confirmed, by analysis of the inferred amino acid sequence, as the 60-kDa Cr outer membrane protein associated with differentiation of reticulate bodies (RBs) into elementary bodies (EBs). The other smaller 15-kDa protein contained a high percentage of methionine and cysteine and may correspond to a reported smaller and co-ordinately synthesised Cr outer-membrane protein also associated with RB to EB differentiation. Sequencing showed three potential stem-loop structures within the 5', 3' and intergenic regions of the cloned fragment. Southern-blot analysis revealed that the cloned fragment is conserved in ten serovars of C. trachomatis and that a strongly cross-hybridising fragment is also present in Chlamydia psittaci.

Respiratory sensation and pattern of respiratory muscle activation during diaphragm fatigue

We have examined the relationship between respiratory effort sensation (modified Borg scale) and amplitude of the integrated surface electromyogram of the diaphragm (Edi, esophageal electrode), rib cage muscles (Erc), and sternomastoid muscle (Esm) during the development of diaphragm fatigue in five normal subjects. Three conditions were studied: run A: transdiaphragmatic pressure (Pdi), 65% Pdimax; esophageal pressure (Pes), 60% Pesmax; run B: Pdi, 50% Pdimax; Pes, 60% Pesmax; and run C: Pdi, 50% Pdimax; Pes, 20% Pesmax. During all runs there was a progressive rise in sensation, which was greater in runs A and B than in run C (P less than 0.05, analysis of variance). There was no difference between runs A and B. At the end of run C subjects did not report a maximal Borg score despite their inability to generate the target Pdi. The increase in sensory score with fatigue correlated highly with Esm/Esmmax and with Erc/Ercmax. There was no correlation between sensory score and Edi/Edimax. We conclude that the increase in respiratory effort sensation that accompanies diaphragm fatigue is not due to perception of increased diaphragmatic activation. It may reflect increased overall respiratory motor output not directed to the diaphragm.

Epitope mapping with solid-phase peptides: identification of type-, subspecies-, species- and genus-reactive antibody binding domains on the major outer membrane protein of Chlamydia trachomatis

The major outer membrane protein (MOMP) of Chlamydia trachomatis carries serovar-, subspecies-, species- and genus immunodomains, antibodies to which may be protective. We have compared the inferred amino acid sequences for MOMP from different serovars of C. trachomatis and from Chlamydia psittaci to identify the likely locations of these sero-taxonomic epitopes. Overlapping peptides corresponding to each of these regions were synthesized on a solid phase and probed with monoclonal antibodies (MAbs) of appropriate specificities. We describe the primary structures of the binding sites of MAb to each of these four epitopes on C. trachomatis serovar L1 MOMP.

High-level expression and epitope localization of the major outer membrane protein of Chlamydia trachomatis serovar L1

Fragments of the gene encoding the major outer membrane porin protein (MOMP) of Chlamydia trachomatis serovar L1 were ligated into the pUC plasmid vectors to give a series of overlapping recombinants expressing MOMP from the lac promoter. Induction of this promoter with IPTG leads to high-level expression of the recombinant porin protein. Electron microscopy shows the presence of insoluble inclusions within the Escherichia coli host cells. Probing the expressed MOMP fragments with a set of monoclonal antibodies permitted localization of the four binding sites (epitopes) of primary-sequence-dependent monoclonal antibodies that exhibit genus-, species-, subspecies- and type (serovar)-specific reactivities.

Gonococcal and chlamydial antibodies in ectopic and intrauterine pregnancy

Sera from 50 women with ectopic pregnancy and 50 age-matched control women with intrauterine pregnancy were tested by enzyme-linked immunosorbent assay (ELISA) using C. trachomatis and N. gonorrhoeae pili as antigens. In the ectopic pregnancy group 76% had IgG antibodies to C. trachomatis compared with 38% in the controls. The prevalence of gonococcal IgG antibody was 32% in the ectopic pregnancy group and 4% in the controls. The prevalences of IgA antibodies to the two organisms ranged from 2 to 12% and were similar in the two groups; cultures for C. trachomatis from cervical swabs from the ectopic pregnancy group were negative. Chlamydial antigen was detected (by ELISA) in exfoliated cervical cells of only one patient in this group.

Optimization of respiratory muscle relaxation during mechanical ventilation

The authors calculated the active work of inspiration (Wp) and the inspiratory muscle pressure-time product (integral of Pmus.dt) in seven patients undergoing mechanical ventilation (MV). This was done by comparing the areas under the inflation pressure-volume and inflation pressure-time curves generated when the patient was contributing to the work of ventilation with those following sedation, when inspiratory muscle activity was absent (defined as absence of diaphragmatic EMG activity and of palpable accessory muscle contraction). Inspiratory muscle inactivity could be predicted by the observation of a smooth rise in inflation pressure that was highly reproducible from breath to breath. Relaxation was present without sedation during MV in the control mode with inspiratory flow rates above 65 1/min. In the assist mode (AMV), both Wp and integral of Pmus.dt were significantly (P less than 0.05) greater than in the control (CMV) mode. Reducing trigger sensitivity during AMV further increased Wp and integral of Pmus.dt (P less than 0.05). During AMV and CMV Wp and integral of Pmus.dt decreased with increasing rate of inspiratory flow delivered by the ventilator. With AMV at low trigger sensitivity and low flow rates, Wp approached 65% of the total inspiratory work. The authors conclude that inspiratory muscle activity can be substantial during MV, particularly during AMV at low trigger sensitivity and flow. Monitoring of inflation pressure is a simple means of determining the degree of inspiratory muscle rest during MV.

Analysis of the entire nucleotide sequence of the cryptic plasmid of Chlamydia trachomatis serovar L1. Evidence for involvement in DNA replication

Chlamydia trachomatis serovar L1/440/LN possesses a 7498bp plasmid which was designated pLGV440. The plasmid was cloned at the BamH1 site of pAT153 into Escherichia coli and the recombinant plasmid was designated pCTL1. A detailed restriction endonuclease map of pCTL1 was constructed. A fragment of the chlamydial plasmid was shown to function as a promoter in E. coli when placed upstream of the lacZ gene. The entire plasmid was sequenced by the chain termination method. Open reading frames were identified from the resulting consensus sequence together with a candidate for the plasmid origin of replication consisting of four perfect tandem repeats of a 22bp sequence, an A:T rich sequence and an open reading frame which could generate a 34.8kdal product. The predicted polypeptide products of the open reading frames were compared by computer with all reported protein sequences. Homology of the predicted polypeptide product of an open reading frame to the E. coli dnaB protein and the analogous product of gene 12 of bacteriophage P22 is described.

Detection of Chlamydia trachomatis by enzyme immunoassay in patients with trachoma

Trachoma control necessitates identification of individuals shedding ocular chlamydiae. Conventional techniques of chlamydial culture are unsuitable for large field surveys in developing countries. In this study an enzyme immunoassay (EIA) developed for the detection of chlamydial antigen in genital-tract infection was used in trachoma. Conjunctival swabs were taken for chlamydial antigen detection from 1225 subjects in a Gambian village with endemic trachoma. Of these, 997 had insignificant or no disease and 172 had mild, 30 moderate, and 26 severe disease. Chlamydial antigen was detected in 5.0%, 20.3%, 46.7%, and 26.9% of subjects in these four categories, respectively. Samples for chlamydial isolation were obtained from 259 subjects. The corresponding rates of detection obtained by chlamydial isolation were 3/90 (3.3%), 16/129 (12.4%), 7/21 (33.3%), and 7/19 (36.8%). If isolation is taken as the "gold standard", the EIA technique had a sensitivity of 70.6% and a specificity of 90%. A substantial proportion of subjects with severe conjunctival scarring, from whom chlamydiae cannot generally be isolated, were antigen positive by EIA, implying that persistent chlamydial antigen plays a part in the pathogenesis of the late sequelae of trachoma.

Chlamydial and gonococcal antibodies in sera of infertile women with tubal obstruction

Sera from 48 infertile women with tubal pathology and from 77 infertile women with normal fallopian tubes were tested by enzyme linked immunosorbent assay (ELISA) using Chlamydia trachomatis and Neisseria gonorrhoeae antigens. Control sera were obtained from women undergoing abortion, sterilisation, and from women practising barrier contraception. The results of ELISA for antibodies to chlamydiae were in close agreement with results published previously of an immunofluorescence test on these sera. Antibodies to C trachomatis were found in 73% of the infertile women with tubal pathology, significantly more than in any of the control groups. Only a very low prevalence (2-5%) of antibodies to gonococcal pili was found in all groups, except women undergoing abortion (16%).

Antigenic specificity of human antibody to chlamydia in trachoma and lymphogranuloma venereum

An understanding of the molecular basis of the humoral immune response to chlamydial infections in man requires the identification of target antigens to which antibodies are directed. The antigenic specificity of antibody from patients with lymphogranuloma venereum (LGV) or trachoma was therefore assessed by Western blotting. Surface polypeptides were first identified using purified chlamydial outer membrane complex as antigen. Antibodies in sera from patients with LGV but not from control negative sera reacted with a wide range of chlamydial surface polypeptides with molecular masses of 19, 29, 41, 58, 63 and 65 kDa. The major component of the antibody response detected by both immunoblotting and immunoprecipitation assay was directed against the major outer membrane protein (MOMP). Antibody to MOMP was species-specific on Western blotting, whereas antibody to several other polypeptides recognized common immunodeterminants on polypeptides of C. psittaci Cal-10 of equivalent molecular mass. Immunologically C. psittaci Cal-10 was more closely related to LGV strains of C. trachomatis than a guinea pig inclusion conjunctivitis strain of C. psittaci. Trachoma sera collected from a village in southern Iran showed predominantly type-specific antibody on micro-immunofluorescence to serotype A or B trachoma agents. These sera showed a weak immune response to MOMP, a pronounced response to a polypeptide of 36 kDa and much less widespread reactivity with other chlamydial polypeptides. The lack of an immune response to SDS-stable immunodeterminants on MOMP might contribute to the susceptibility of trachoma patients to repeated cycles of ocular infection with chlamydiae.

Fire in the operating theatre. Evacuation pre-planning may save lives

An operating theatre fire and the steps taken to deal with it are described; the difficulties encountered in evacuating anaesthetised patients are highlighted. Measures which might be taken to prevent recurrence of these problems, and recommendations on the institution of fire drills for the safety of patients and staff are given.

Effect of chronic lung disease on the perception of added inspiratory loads

The perceived magnitude of externally added loads to breathing was estimated in 10 normal subjects and 10 patients with chronic lung disease (5 obstructive, 5 interstitial disorders) to determine if chronic mechanical abnormalities of the respiratory system are accompanied by changes in the perception of dyspnea. Flow rates and tidal volumes were varied to assess the effect of altered patterns of breathing. With added resistive loads, the perceived magnitude increased as both resistance and the flow rate increased. With elastic loads the perceived magnitude increased as both elastance and tidal volume increased. In all subjects, perceived magnitude of added loads was most directly related to the inspiratory pressure used to overcome the load. Although the exponent for the power function relationship between perceived magnitude and the physical magnitude of the load was affected by the subject's age, there was no difference between the patients studied and the age-matched normal subjects. The results indicate that the sensation associated with added loads to breathing is the same in patients with chronic lung disease as in normal subjects. Also, they suggest that the altered pattern of breathing in patients with chronic lung disease is a behavioral adaptation to minimize respiratory distress.

Celiac disease and spinocerebellar degeneration with normal vitamin E status

We studied a 47-year-old man with spinocerebellar degeneration and malabsorption due to celiac enteropathy; the serum vitamin E level was normal. The neurologic disorder initially deteriorated despite improvement of small bowel histology on a gluten-free diet and vitamin E therapy, but later stabilized. The etiology of the neurologic disorder in adult celiac disease has not been identified and does not appear to be vitamin E deficiency.

Simple mastectomy under local anaesthesia

Nine patients with locally advanced carcinoma of the breast underwent simple mastectomy under regional anaesthesia (1% lignocaine and 1:100,000 adrenaline). Preoperative sedation was provided by oral lorazepam. There were no technical problems, evidence of lignocaine toxicity or excessive operative blood loss and no wounds became infected.

Respiratory obstruction following vocal cord injection of Teflon paste

Injection of poly(tetrafluoroethylene) past (Teflon) into vocal cords is becoming more common, but immediate morbidity has not previously been described. A case is reported in which acute airway obstruction followed the injection of Teflon paste into a paralysed vocal cord. This was easily managed, without resort to tracheostomy, by topical lignocaine which reduced the overactivity of the normal vocal cord.