Plasminogen II accumulates five times faster than plasminogen I at the site of a balloon de-endothelializing injury in vivo to the rabbit aorta: comparison with other hemostatic proteins

In the rabbit blood stream, plasminogen circulates as two glycoforms, plasminogen I (PLG-I) and plasminogen II (PLG-II), in a molar ratio of 1:2.2. To compare their relative behaviors toward a site of vascular injury, radiolabeled samples of PLG-I and PLG-II were coinjected intravenously into NZW rabbits before inducing a de-endothelializing (balloon catheter) injury to the thoracic aorta. At various times (5 to 60 minutes) after injury, each rabbit was anesthetized and exsanguinated, the aorta was excised, and the radioactivity per centimeters squared of aortic intima-media (IM) was measured relative to that of blood at exsanguination. The uptake of iodine 125-labeled PLG-I and iodine 131-labeled PLG-II showed that the IM was essentially saturated by both glycoforms by 30 to 40 minutes after injury. Extrapolation of the flux rates to 1 minute after injury indicated that the uptake of PLG-II (2.4 pmol/min/cm2) exceeded PLG-I (0.5 pmol/min/cm2) almost five-fold. This result is consistent with an earlier report (Metabolism 1994;43:1430-7) that PLG-II is released by the liver and catabolized in vivo approximately five times faster than PLG-I. By molar comparison, the flux of total plasminogen (ie, PLG-I plus PLG-II) into the injured aorta wall in vivo was 2.4 times greater than that for prothrombin. Assuming both zymogens are converted to their respective proteases within the wound site, then approximately 2 to 3 molecules of plasmin are released for each molecule of thrombin in vivo. The possible significance of this plasmin:thrombin ratio is discussed in respect to the turnover of fibrin(ogen) within the site of vascular injury.

Identification of an HLA-A11 serological variant and its characterization by sequencing based typing

We have identified an HLA-A11 variant allele, A*1105, segregating in a Caucasoid family. The variant antigen expressed by this allele failed to cross-react with most Caucasoid anti-HLA-A11 antisera tested. Sequencing based typing has been used to characterize this new allele and this showed that it has a novel mutation at a polymorphic position (502) in exon 3. In comparison with A*1101, the mutation (A-->G) results in an amino acid change from positively-charged lysine to negative glutamate and this may explain the altered HLA-A11 serological profile exhibited by this antigen. The new allele was found in a patient with acute lymphoid leukaemia (ALL), her father and two siblings.

Identification of a new variant, HLA-Cw*1507, differing from Cw*1502 only at the KIR-related dimorphism of codons 77 and 80

We describe here a novel allele, HLA-Cw*1507, identified by polymerase chain reaction using sequence-specific primers (PCR-SSP) and sequence-based typing (SBT). Cw*1507 is similar to Cw*1502 with differences at nucleotide positions 302 (A to G) and 312 (A to C) in exon 2. The substitutions observed in Cw*1507, change codon 77 from AAC (asparagine) to AGC (serine) and codon 80 from AAA (lysine) to AAC (asparagine), compared to Cw*1502. Residues 77 and 80 of HLA-C alleles are located in the alpha 1 domain, where they can influence interaction between antigenic peptides and the T-cell receptor. Also, the dimorphism at these residues from asparagine and lysine to serine and asparagine, respectively, are known to modulate interaction with the natural killer (NK) cell killer inhibitory receptor (KIR). The new HLA-Cw*1507, together with Cw*1502, represents the fourth pair of HLA-C alleles differing only at the KIR-related dimorphic codons 77 and 80.

Indirect evidence of human skeletal muscle damage and collagen breakdown after eccentric muscle actions

Indirect markers of muscle damage and collagen breakdown were recorded for up to 9 days after a bout of concentric, followed by a bout of eccentric, muscle actions. Nine untrained participants performed two bouts of 50 maximum effort repetitions on an isokinetic dynamometer (angular velocity 1.05 rad x s(-1), range of motion 1.75 rad). An initial concentric bout of muscle actions was followed by an eccentric bout 21 days later, using the same knee extensors. Concentric actions induced no changes in maximum voluntary isometric contraction force (MVC), nor induced any changes in the serum enzyme activities of creatine kinase, a lactate dehydrogenase isoenzyme (LDH-1), or alkaline phosphatase. Similarly, concentric actions induced no change in markers of collagen breakdown, namely plasma hydroxyproline and serum type 1 collagen concentration. In contrast, eccentric actions induced a 23.5+/-19.0% (mean+/-s) decrease in MVC immediately post-exercise (P < 0.05), and increased the serum enzyme activities of creatine kinase and LDH-1 to 486+/-792 and 90+/-11 IU.l(-1) respectively on day 3 post-exercise, and to 189+/-159 and 96+/-13 IU x l(-1) respectively on day 7 post-exercise (all P< 0.05). Eccentric actions induced no significant changes in plasma hydroxyproline, but increased collagen concentration on days 1 and 9 post-exercise (48.6% and 44.3% increases above pre-exercise on days 1 and 9 respectively; both P < 0.05). We conclude that eccentric but not concentric actions may result in temporary muscle damage, and that collagen breakdown may also be affected by eccentric actions. With caution, indices of collagen breakdown may be used to identify exercise-induced damage to connective tissue.

Flow cytometry and squamous cell carcinoma of the maxillary sinus: A possible prognostic indicator for multimodality intervention

Malignant tumors of the paranasal sinuses constitute less than 1% of all malignancies. Unfortunately, few prognostic factors have been identified regarding the efficacy of interventional therapy. Patients with carcinoma of the maxillary sinus frequently present with an advanced stage of disease and multimodality therapy is often proposed. Although some tumors appear to be more sensitive to preoperative chemotherapy and radiation therapy, a method of predicting and evaluating tumor behavior has not been recognized. Introduced as a means of identifying cell populations with abnormalities in total DNA content, flow-cytometric DNA analysis provides a quick and reliable means of tumor characterization for many malignancies. Although nuclear DNA content has been implicated as a prognostic factor in an increasing number of tumor types, current data on the role of DNA content in head and neck carcinoma is conflicting and incomplete. To evaluate the role of flow-cytometric DNA analysis in predicting therapeutic alternatives, 22 patients with squamous cell carcinoma of the maxillary sinus were reviewed. Patient outcome and histopathologic grade were retrospectively compared with flow-cytometric evaluations of paraffin-embedded formalin-fixed tumor specimens. Four of sixteen tumors (25%) were found to be aneuploid and were also associated with an increased survival rate (p < 0.01). This initial data emphasizes the possible usefulness of DNA measurement for characterization of squamous cell carcinoma of the maxillary sinus and stresses the need for further evaluation.

Delusional ideation in religious and psychotic populations

OBJECTIVES

Previous research into schizotypy has shown that certain groups of people have similar experiences to the positive symptoms of schizophrenia but remain functioning members of society, such as those with profound religious experiences (Jackson & Fulford, 1997).

METHOD

The focus of the present study was to explore the incidence of delusional ideation in New Religious Movements (NRMs). Hare Krishnas and Druids were compared to two control groups (non-religious and Christian), and to deluded, psychotic in-patients on two delusions measures.

RESULTS

As predicted, individuals from the NRMs scored significantly higher than the control groups on all the delusional measures apart from levels of distress. They did not show as much florid symptomatology as the psychotic patients, but could not be differentiated from the deluded group on the number of delusional items endorsed on the Peters et al. Delusions Inventory (PDI; Peters, Day & Garety, 1996), or on levels of conviction. However, they were significantly less distressed and preoccupied by their experiences. No differences were found between the two control groups on any of the delusional measures, suggesting that religious beliefs per se do not account for the NRMs members' scores.

DISCUSSION

These findings provide further support for, first, the notion of a continuum between normality and psychosis and, second, for the necessity to consider the multidimensionality of delusional beliefs.

A novel HLA allele, HLA-B*5113, identified in the Kolla Amerindians of North-West Argentina

A novel HLA-B51 allele, B*5113, was identified in a Kolla Amerindian individual from North-West Argentina. HLA-B*5113 differs from B*51011 by two nucleotide substitutions, one synonymous, the other nonsynonymous. The resulting amino acid difference at residue 116 in the HLA-B molecule's peptide binding site is likely to affect the nature of the peptides which bind to this molecule. The finding of this novel allele supports previous findings of increased diversity at HLA-B in Amerindian groups.

Changes in indices of antioxidant status, lipid peroxidation and inflammation in human skeletal muscle after eccentric muscle actions

This study investigated the effects of chronic muscle inflammation on indices of antioxidant status and muscle injury after eccentric exercise. Eight subjects each performed 70 maximal voluntary eccentric muscle actions on an isokinetic dynamometer, using the knee extensors of a single leg. Venous blood samples were collected into serum and EDTA tubes 5 and 3 days before exercise, immediately before exercise, and then again on days 3, 4, 5, 6, 7, 10 and 12 after the bout. Needle biopsies were taken from the vastus lateralis of six subjects, a week before exercise (baseline), and again on days 4 and 7 post-exercise. The concentrations of malondialdehyde in plasma and muscle were used as markers of lipid peroxidation. Creatine kinase activity, beta-glucuronidase activity and total antioxidant capacity were determined in serum. In muscle, aqueous and bound total antioxidant capacity, the aqueous sulphydryl concentration, and beta-glucuronidase and glucose-6-phosphate dehydrogenase activity were determined. No changes were detected in serum total antioxidant capacity, serum creatine kinase and beta-glucuronidase after the baseline biopsy. After exercise serum creatine kinase and beta-glucuronidase were elevated although other serum measures were unchanged. In muscle, aqueous and bound total antioxidant capacity, sulphydryls, glucose-6-phosphate dehydrogenase and beta-glucuronidase were all elevated. Despite evidence of inflammation in this study, muscle antioxidant status was not compromised, and malondialdehyde was unaltered in muscle and plasma. Therefore, this study provides no evidence that chronic muscle inflammation compromises antioxidant status or increases lipid peroxidation.

Identification of an HLA-C variant allele, Cw*0805, by sequencing based typing

We have identified a variant HLA-C allele, Cw*0805, in DNA isolated from a blood sample used in the UK National External Quality Assessment Scheme for Histocompatibility and Immunogenetics. The DNA was initially typed by PCR-SSP and PCR-SBT as Cw*0802, 1602 with a single mismatch in exon 2 of one of the alleles. The two HLA-C alleles were separated by locus- and allele-specific PCRs and sequencing analysis showed that the Cw*0802 allele was variant in this sample, with a single mismatch in exon 2 at position 289.

Sexual networks: the integration of social and genetic data

New methods for studying sexual networks are presented, drawing upon routine procedures followed in genitourinary medicine clinics in the UK for tracing partners and identifying strains of infection. The routine social procedures were developed to incorporate a structured interview. The routine microbiological diagnosis of gonorrhoea was augmented by phenotyping and the development of new genetic techniques for the fine discrimination of gonococcal strains (opa-typing). Selected results from a study in Sheffield, UK show that each method has limitations, when conducted separately, but these are minimised when the methods are combined. Moreover, the use of simple and routine methods of data collection resolve issues of scale and sample that have beset other network studies, as they provide a means of covering a larger and defined population. Popular concepts about these methods are discussed in the conclusion. The integrated approach employed in our research raises questions both about social methods, 'of people who lie, particularly when they talk about sex', and about microbiological methods, 'of genes that tell the truth' and bypass what people say and think altogether. We argue that these stereotypes are misleading insofar as they suggest that genetic techniques can substitute for the social, and we suggest that even the finest discrimination of organisms at the genetic level will never obviate the need for their interpretation in the light of social data.

Partner notification for gonorrhoea: a comparative study with a provincial and a metropolitan UK clinic

OBJECTIVE

To compare partner notification practice and outcomes at a provincial and a metropolitan clinic.

DESIGN

Prospective study, following standardisation of partner notification policy.

SETTINGS

Sheffield Department of Genitourinary Medicine, Royal Hallamshire Hospital and Jefferiss Wing Centre for Sexual Health, St Mary's Hospital, London.

SUBJECTS

Consecutive patients with culture positive gonorrhoea between October 1994 and March 1996 who were interviewed by a health adviser.

RESULTS

In Sheffield, 235 cases reported 659 outstanding contacts, of whom 129 (20%) were subsequently screened, and 65 (50%) had gonorrhoea. At St Mary's 510 cases reported 2176 outstanding contacts, of whom 98 (5%) were known to have been screened, and 53 (54%) had gonorrhoea. Patient or provider referral agreements appeared more productive in Sheffield, where 60% resulted in contact attendance, compared with 13% at St Mary's. Provider referral was used more frequently in Sheffield, for 44% of referrals, compared with 1% at St Mary's. Multivariate analysis showed that partner notification was less effective for casual and short term (< 7 days) partnerships in both centres, and for homosexual men at St Mary's.

CONCLUSION

Partner notification outcomes were better in the provincial setting where contact attendance could be recorded more reliably and provider referral was used more extensively. The high proportion of contacts who remained untraced in both settings indicates the need for complementary screening and prevention initiatives.

Sexual histories, partnerships and networks associated with the transmission of gonorrhoea

We aimed to describe and compare sexual links among people with gonorrhoea, by studying patients in 2 UK departments of genitourinary medicine. Interviews were completed for 510 and 235 cases in London and Sheffield respectively. There was a greater proportion of cases in men, homosexual men, non-white and non-British people and fewer female sex workers in London. Total networks of 1738 people in London and 570 people in Sheffield were described. Large linked heterosexual networks identified in Sheffield were associated with local contact, including men with higher numbers of sexual partners. Condom use for vaginal sex was reported for 11% of heterosexual partnerships in Sheffield, and 27% in London, with little difference between regular and casual partners. It was more difficult to define networks in London due to a high proportion of relatively anonymous contacts. These difficulties suggest that research and interventions may profitably focus upon venues for meeting partners as well as partner notification.

Double data entry: what value, what price?

We challenge the notion that double data entry is either sufficient or necessary to ensure good-quality data in clinical trials. Although we do not completely reject that notion, we quantify some of the effects that poor quality data have on final study results in terms of estimation, significance testing, and power. By introducing digit errors into simulated blood pressure measurements we demonstrate that simple range checks allow us to detect (and therefore correct) the main errors that impact the final study results and conclusions. The errors that cannot easily be detected by such range checks, although possibly numerous, are shown to be of little importance in drawing the correct conclusions from the statistical analysis of data. Exploratory data analysis cannot identify all errors that a second data entry would detect, but on the other hand, not all errors that are found by exploratory data analysis are detectable by double data entry. Double data entry is concerned solely with ensuring, to a high degree of certainty, that what is recorded on the case record form is transcribed into the database. Exploratory data analysis looks beyond the case record form to challenge the plausibility of the written data. In this sense, the second entering of data has some benefit, but the use of exploratory data analysis methods, either as data entry is ongoing or at the end of data entry and as the first stage in an analysis strategy, should always be mandatory.

The use of cold compression dressings after total knee replacement: a randomized controlled trial

This prospective, controlled study compared cold compressive dressings with wool and crepe in the postoperative management of patients undergoing total knee replacement (TKR). Forty TKR patients were assessed for blood loss, pain, swelling, and range of motion. Patients in the cold compression group had less blood loss through suction drainage (982 mL versus 768 mL). A higher proportion of patients in the treatment group did not require blood transfusion postoperatively. Mean opiate requirements were lower in the cold compression group (0.57 versus 0.71 mg/kg/48 hours). The cold compression device appeared to reduce blood loss and pain following TKR.

Sexual networks and the transmission of HIV in London

This paper discusses ways in which empirical research investigating sexual networks can further understanding of the transmission of HIV in London, using information from a 24-month period of participant observation and 53 open-ended, in-depth interviews with eighteen men and one woman who have direct and indirect sexual links with each other. These interviews enabled the identification of a wider sexual network between 154 participants and contacts during the year August 1994-July 1995. The linked network data help to identify pathways of transmission between individuals who are HIV+ and those who are HIV-, as well as sexual links between 'older' and 'younger' men, and with male prostitutes. There appears to be considerable on-going transmission of HIV in London. The majority of participants reported having had unprotected anal and/or vaginal sex within a variety of relationships. The implications of these findings for policies designed to prevent the transmission of HIV are discussed.

Sex workers and the control of sexually transmitted disease

OBJECTIVES

To describe and assess measures to control sexually transmitted diseases (STDs) among sex workers and their partners.

METHODS

A review of medical, historical and social literature, focusing on selected cases.

RESULTS

Measures to control disease in sex workers today are often prompted by concerns about HIV transmission. However, the literature shows that prostitution varies from one place and time to another, together with the risk of sexually transmitted disease. A broad social definition of prostitution rather than a narrow reference to levels of sexual activity is important for effective disease control, as an understanding of the relation between social disadvantage and sexual activity enables the provision of occupational services that sex workers actually want and use. Social prejudice and legal sanctions cause some sex workers and their partners to avoid even the most appropriate and accessible specialist services. Therefore targeted programmes can only complement, and not replace, general measures to control STDs, which are developed for other social groups or the local population as a whole.

CONCLUSIONS

Sex workers and sex work differ from one place to another and so a single model for STD control is inappropriate. None the less, occupational health risks suggest a general need for specialist services. Where these do not compound the disadvantages that sex workers already suffer, medical services are likely to offer significant benefits in prevention, early diagnosis, and treatment of STDs. As the stigma of prostitution leads many people to remain invisible to services, a general health infrastructure and anti-discriminatory measures will be equally important to effective disease control.

Reduction of trachoma in a sub-Saharan village in absence of a disease control programme

BACKGROUND

Trachoma is a leading cause of blindness in the developing world and is most prevalent among people who live in poor rural communities in arid locations.

METHODS

We analysed the results of surveys of trachoma prevalence in Marakissa, a rural village in The Gambia. These surveys were undertaken in 1959, by the Medical Research Council, and in 1987 and 1996 by the Gambian National Eye Care Programme.

FINDINGS

During this 37-year period, the prevalence of active inflammatory trachoma among children aged 0-9 years fell from 65.7 cases per 100 children in 1959 to 2.4 cases per 100 children in 1996. The prevalence also fell dramatically among people of 10-19 years (52.5 to 1.4 per 100) and among people of 20 years and older (36.7 to 0 cases per 100).

INTERPRETATION

The dramatic fall in disease occurrence was paralleled by improvements in sanitation, water supply, education, and access to health care in the village. Of particular importance is that the decline in trachoma occurred without any trachoma-specific intervention.

Molecular mechanism underlying the action of a novel fusion inhibitor of influenza A virus

In the initial stages of influenza virus infection, the hemagglutinin (HA) protein of influenza virus mediates both adsorption and penetration of the virus into the host cell. Recently, we identified and characterized BMY-27709 as an inhibitor of the H1 and H2 subtypes of influenza A virus that specifically inhibits the HA function necessary for virus-cell membrane fusion (G.-X. Luo, R. Colonno, and M. Krystal, Virology 226:66-76, 1996). Studies presented herein show that the inhibition is mediated through specific interaction with the HA protein. This binding represses the low-pH-induced conformational change of the HA protein which is a prerequisite for membrane fusion. In an attempt to define the binding pocket within the HA molecule, a number of drug-resistant viruses have been isolated and characterized. Sequence analyses of the HA gene of these drug-resistant viruses mapped amino acid changes responsible for drug resistance to a region located near the amino terminus of HA2. In addition, we have identified inactive analogs of BMY-27709 which are able to compete out the inhibitory activity of BMY-27709. This finding suggests that inhibition of the HA-mediated membrane fusion by this class of compounds is not solely the result of binding within the HA molecule but requires specific interactions.

Combined sequestration, bronchogenic cyst, and dysgenetic lung simulating congenital lobar emphysema

We report the case of a newborn with bronchopulmonary sequestration, bronchogenic cyst, and dysgenetic lung that radiographically simulated congenital lobar emphysema. We discuss congenital malformations of the lungs and the concept of a continuum in the development of pulmonary anomalies.

Sexual partner networks in the transmission of sexually transmitted diseases. An analysis of gonorrhea cases in Sheffield, UK

BACKGROUND AND OBJECTIVES

Routine contact tracing data on patients with gonorrhea are used to identify sexual partner networks. These are combined with gonococcal typing data to study patterns of transmission. The role of persons in transmission is discussed.

STUDY DESIGN

Contact tracing data on patients with gonorrhea attending the Royal Hallamshire Hospital in Sheffield in 1988 and 1989 are analyzed. Gonococcal strains identified by auxotype/serovar (A/S) class are combined with these data to identify transmission paths.

RESULTS

The network contained 1,272 persons, 724 (77%) of whom had gonorrhea during the study period. Four hundred two clusters of linked cases were identified. The largest cluster, containing 35 persons connected over 16 months, is discussed in greater detail to illustrate how these data may help identify patterns of transmission and the role of persons.

CONCLUSION

Contact tracing data can be used to identify sexual partner networks and to study transmission patterns. Microbiologic data can aid interpretation. An person's risk of acquiring infection depends on indirect links as well as direct links. To understand patterns of transmission it may be important to distinguish between those involved in transmission and those only acquiring infection. Networks established through gonococcal transmission are also relevant to the transmission of other sexually transmitted diseases.