The Reality of Antimicrobial Resistance and Antibiotic Usage Data in Asia: The CAPTURA Experience

Antimicrobial resistance (AMR), particularly in low- and middle-income countries, is threatening to undermine advances in health and development. Scarce technical and human resources in these countries limit the collection of quality AMR data for evidence-based decision-making. The CAPTURA consortium, funded by the Fleming Fund, was implemented across 7 countries in the South and Southeast Asian region. The program focused on collating historical bacteriological data for qualitative and quantitative analyses. The team gathered standard data on the quality of laboratories and clinics and the quality and quantity of retrospective historical AMR data. In addition, retrospective data on antimicrobial use and consumption were analyzed. While standard protocols guided the project, a tailored approach for stakeholder engagement was implemented to work with countries and secure data-sharing agreements. The program also had to navigate the challenges of the COVID-19 pandemic, making some innovative adaptations to overcome logistical barriers. From 2018 through 2022, a large body of data was collected that was used to base a series of recommended key measures for strengthening the development of standardized national surveillance programs and to support alignment with international efforts.

Ultratunable Quantum Frequency Conversion in Photonic Crystal Fiber

Quantum frequency conversion of single photons between wavelength bands is a key enabler to realizing widespread quantum networks. We demonstrate the quantum frequency conversion of a heralded 1551 nm photon to any wavelength within an ultrabroad (1226-1408 nm) range in a group-velocity-symmetric photonic crystal fiber, covering over 150 independent frequency bins. The target wavelength is controlled by tuning only a single pump laser wavelength. We find internal, and total, conversion efficiencies of 12(1)% and 1.4(2)%, respectively. For the case of converting 1551 to 1300 nm we measure a heralded g^{(2)}(0)=0.25(6) for converted light from an input with g^{(2)}(0)=0.034(8). We expect that this photonic crystal fiber can be used for myriad quantum networking tasks.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

The safety of paediatric surgery between COVID-19 surges: an observational study

Despite the ongoing coronavirus disease 2019 (COVID‐19) pandemic, elective paediatric surgery must continue safely through the first, second and subsequent waves of disease. This study presents outcome data from a children's hospital in north‐west England, the region with the highest prevalence of COVID‐19 in England. Children and young people undergoing elective surgery isolated within their household for 14 days, then presented for real‐time reverse transcriptase polymerase chain reaction testing for severe acute respiratory syndrome coronavirus disease‐2 (SARS‐CoV‐2) within 72 h of their procedure (or rapid testing within 24 h in high‐risk cases), and completed a screening questionnaire on admission. Planned surgery resumed on 26 May 2020; in the four subsequent weeks, there were 197 patients for emergency and 501 for elective procedures. A total of 488 out of 501 (97.4%) elective admissions proceeded, representing a 2.6% COVID‐19‐related cancellation rate. There was no difference in the incidence of SARS‐CoV‐2 among children and young people who had or had not isolated for 14 days (p > 0.99). One out of 685 (0.1%) children who had surgery re‐presented to the hospital with symptoms potentially consistent with SARS‐CoV‐2 within 14 days of surgery. Outcomes were similar to those in the same time period in 2019 for length of stay (p = 1.0); unplanned critical care admissions (p = 0.59); and 14‐day hospital re‐admission (p = 0.17). However, the current cohort were younger (p = 0.037); of increased complexity (p < 0.001) and underwent more complex surgery (p < 0.001). The combined use of household self‐isolation, testing and screening questionnaires has allowed the re‐initiation of elective paediatric surgery at high volume while maintaining pre‐COVID‐19 outcomes in children and young people undergoing surgery. This may provide a model for addressing the ongoing challenges posed by COVID‐19, as well as future pandemics.

Resource-efficient frequency conversion for quantum networks via sequential four-wave mixing

We report a resource-efficient scheme in which a single pump laser was used to achieve frequency conversion by Bragg-scattering four-wave mixing in a photonic crystal fiber. We demonstrate bidirectional conversion of coherent light between Sr⁺²P_1/2→²D_3/2 emission wavelength at 1092 nm and the telecommunication C band with conversion efficiencies of 4.2% and 37% for up- and down-conversion, respectively. We discuss how the scheme may be viably scaled to meet the temporal, spectral, and polarization stability requirements of a hybrid light-matter quantum network.

Bacterial co-infection and early mortality among pulmonary tuberculosis patients in Manila, The Philippines

OBJECTIVE

To investigate the prevalence of bacterial co-infection and its effect on early mortality among hospitalised human immunodeficiency virus (HIV) negative pulmonary tuberculosis (PTB) patients in Manila, the Philippines.

DESIGN

A prospective observational study was conducted at a national infectious disease hospital. HIV-negative PTB patients aged 13 years hospitalised from November to December 2011 and from December 2012 to May 2013 were enrolled. Sputum samples were tested for Mycobacterium tuberculosis and six respiratory bacterial pathogens using polymerase chain reaction (PCR).

RESULTS

Of 466 patients, 228 (48.9%) were TB-PCR-positive. Overall, bacterial pathogens in purulent sputum were detected in 135 (29.0%) patients: Haemophilus influenzae was the most common bacterium (21.2%), followed by Streptococcus pneumoniae (7.9%). The prevalence of bacterial co-infection did not differ between TB-PCR-positive and -negative patients. A total of 92 (19.7%) patients died within 2 weeks. Bacterial co-infection was significantly associated with an increased risk of 2-week mortality among TB-PCR-positive patients (adjusted risk ratio [aRR] 1.67, 95%CI 1.03-2.72). This association was also observed but did not reach statistical significance among TB-PCR-negative patients (aRR1.7, 95%CI 0.95-3.02).

CONCLUSION

Bacterial co-infection is common and contributes to an increased risk of early mortality among HIV-negative PTB patients.

Hughes Abdominal Repair Trial (HART) - Abdominal wall closure techniques to reduce the incidence of incisional hernias: study protocol for a randomised controlled trial

Background

Incisional hernias are common complications of midline closure following abdominal surgery and cause significant morbidity, impaired quality of life and increased health care costs.

The ‘Hughes Repair’ combines a standard mass closure with a series of horizontal and two vertical mattress sutures within a single suture. This theoretically distributes the load along the incision length as well as across it. There is evidence to suggest that this technique is as effective as mesh repair for the operative management of incisional hernias; however, no trials have compared the Hughes Repair with standard mass closure for the prevention of incisional hernia formation following a midline incision.

Methods/design

This is a 1:1 randomised controlled trial comparing two suture techniques for the closure of the midline abdominal wound following surgery for colorectal cancer. Full ethical approval has been gained (Wales REC 3, MREC 12/WA/0374). Eight hundred patients will be randomised from approximately 20 general surgical units within the United Kingdom. Patients undergoing open or laparoscopic (more than a 5-cm midline incision) surgery for colorectal cancer, elective or emergency, are eligible. Patients under the age of 18 years, those having mesh inserted or undergoing musculofascial flap closure of the perineal defect in abdominoperineal wound closure, and those unable to give informed consent will be excluded. Patients will be randomised intraoperatively to either the Hughes Repair or standard mass closure. The primary outcome measure is the incidence of incisional hernias at 1 year as assessed by standardised clinical examination. The secondary outcomes include quality of life patient-reported outcome measures, cost-utility analysis, incidence of complete abdominal wound dehiscence and C-POSSUM scores. The incidence of incisional hernia at 1 year, assessed by computerised tomography, will form a tertiary outcome.

Discussion

A feasibility phase has been completed. The results of the study will be used to inform current and future practice and potentially reduce the risk of incisional hernia formation following midline incisions.

Trial registration

Trial Registration Number: ISRCTN 25616490. Registered on 1 January 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1573-0) contains supplementary material, which is available to authorized users.

Imaging pancreas transplants

Pancreas transplants are performed in multiple centres across the UK with good graft survival rates. This places an increasing demand on radiology services, particularly as the complication rates are not insignificant. The imaging appearances of pancreas transplants and their complications can be difficult to interpret. This review provides an illustrative journey through the anatomical appearances of a graft and the imaging appearances of complications, as a reference tool for radiologists.

Development of a large animal model for investigating resuscitation after blast and hemorrhage

BACKGROUND

Blast injuries are an increasing problem owing to the widespread terrorist threat, but hemorrhage remains the second leading cause of civilian trauma death. Against this background, increasing numbers of prehospital and military trauma organizations are advocating a hypotensive approach to resuscitation of the hypovolemic casualty, deliberately aiming not to achieve a normal blood pressure so as not to disturb any newly formed blood clots at the site of a vascular injury.

METHODS

There are no data available to guide clinicians as to how best to resuscitate the blast-injured casualty who has also suffered a hemorrhagic injury. A large-scale program was initiated to examine this question and to offer clinical guidance on the optimal resuscitation strategy in such circumstances in terms of volume, type of fluid, speed of resuscitation, and appropriate endpoints. Before such experiments could be undertaken, a novel large animal model of blast and hemorrhage had to be devised and validated. This study outlines the derivation of such a large animal model utilizing terminally anesthetized Large White pigs exposed to a standardized primary blast wave followed by a controlled hemorrhage of 30% of the total blood volume.

RESULTS AND CONCLUSION

The preliminary results confirm the reliability and reproducibility of this model.

The role of the polymerase chain reaction in the diagnosis of bacterial meningitis in Vietnam

Bacterial meningitis remains an important cause of morbidity and mortality in Vietnam. Diagnosis is hampered by the ready availability of antibiotics in the community, leading to late presentation, masked clinical signs, and poor organism detection during the microscopical examination and culture of cerebrospinal fluid (CSF). In order to improve organism detection at the Hospital for Tropical Diseases in Ho Chi Minh City, a diagnostic PCR-based protocol was developed. This protocol was followed in the investigation of CSF samples from 36 patients with clinical signs of bacterial meningitis. Each sample was first tested in a semi-nested PCR using primers for the 16sRNA gene common to all bacteria. The products of this reaction were then amplified using a 16sru8 primer and primers specific for Neisseria meningitidis, Haemophilus influenzae or Streptococcus spp. The samples found positive for Streptococcus were further investigated in a nested PCR using primers specific for the pneumolysin gene of S. pneumoniae. The sensitivity of detection was increased from 36% with culture to 44% with PCR. Although the sample size was small, the results indicate that PCR would be a feasible and useful adjunct in the diagnosis of bacterial meningitis, particularly in areas where community antibiotic use is common.

Complete genome sequence of a multiple drug resistant Salmonella enterica serovar Typhi CT18

Salmonella enterica serovar Typhi (S. typhi) is the aetiological agent of typhoid fever, a serious invasive bacterial disease of humans with an annual global burden of approximately 16 million cases, leading to 600,000 fatalities. Many S. enterica serovars actively invade the mucosal surface of the intestine but are normally contained in healthy individuals by the local immune defence mechanisms. However, S. typhi has evolved the ability to spread to the deeper tissues of humans, including liver, spleen and bone marrow. Here we have sequenced the 4,809,037-base pair (bp) genome of a S. typhi (CT18) that is resistant to multiple drugs, revealing the presence of hundreds of insertions and deletions compared with the Escherichia coli genome, ranging in size from single genes to large islands. Notably, the genome sequence identifies over two hundred pseudogenes, several corresponding to genes that are known to contribute to virulence in Salmonella typhimurium. This genetic degradation may contribute to the human-restricted host range for S. typhi. CT18 harbours a 218,150-bp multiple-drug-resistance incH1 plasmid (pHCM1), and a 106,516-bp cryptic plasmid (pHCM2), which shows recent common ancestry with a virulence plasmid of Yersinia pestis.

Typhoid fever: pathogenesis and disease

Typhoid fever is an infectious disease of global distribution. Although there is a wealth of data on Salmonella typhimurium infection in the mouse and the interaction of this serovar with human cell lines in vitro, there is a relatively small amount of data on S. typhi and the pathogenesis of typhoid fever. In this review we focus on three areas: adherence to and invasion of gut epithelial cells, dissemination to systemic sites, and survival and replication within host cells. In addition, we attempt to put current salmonella research into the context of typhoid fever.

Gender roles and/or styles in crisis: an integrative analysis of the experiences of fathers of children with cancer

Despite a proliferation of research with families of children with cancer and gender differences in parental coping, few studies have explicitly explored the experiences of fathers of children with cancer. Using several different data collection efforts, including semistructured in-depth interviews and open workshops, this integrative analysis views fathers' experiences through the lens of gender. Findings suggest that fathers' experiences can be understood as influenced by gender identities, gender roles, and the gendered organization of support systems, employment, and health care institutions. The results suggest the need for interventions that provide fathers and entire families with the opportunity to develop new skills and coping strategies for dealing with the stresses and challenges of childhood cancer.

Different effects of a single amino acid substitution on three adjacent epitopes in the gp41 C-terminal tail of a neutralizing antibody escape mutant of human immunodeficiency virus type 1

The envelope protein of human immunodeficiency virus type 1 (HIV-1) comprises the outer gp 120 SU domain and the anchoring gp41 TM domain, and the conventional view is that it has a single transmembrane region with the following C-terminal sequence situated entirely within the virion. However, we have recently proposed that the gp41 C-terminal region comprises three transmembrane regions and an external loop structure. Part of this loop is the peptide 731PRGPDRPEGIEEEGGERDRDRS752 that carries three antibody epitopes, 734PDRPEG739, 740IEEE743, and 746ERDRD750. PDRPEG is not detected in virions but reacts with its cognate MAb (C8) in Western blots, IEEE is a linear and non-neutralizing epitope, and ERDRD is a conformational and neutralizing epitope. Here we show that escape mutants selected with neutralizing ERDRD-specific antibody had a single 732R-->G substitution, 14 residues upstream of the cognate epitope, and no longer bound the selecting antibody. The same amino acid substitution altered epitope PDRPEG in the virion so that it now reacted with MAb C8, but left epitope IEEE unaffected. Introduction of 732R-->G by site-specific mutagenesis into the gp41 of cloned HIV-1 NL4-3 virions allowed them to escape neutralization by ERDRD-specific IgG, and confirms that 732R makes a major contribution to the neutralizing conformation of the 731-752 region of the C-terminal tail of gp41.

Typhoid fever and genetic polymorphisms at the natural resistance-associated macrophage protein 1

Control of Salmonella enterica serovar Typhimurium (S. typhimurium) infection in the mouse model of typhoid fever is critically dependent on the natural resistance-associated macrophage protein 1 (Nramp1). In this study, we examined the role of genetic polymorphisms in the human homologue, NRAMP1, in resistance to typhoid fever in southern Vietnam. Patients with blood-culture-confirmed typhoid fever and healthy control subjects were genotyped for 6 polymorphic markers within and near NRAMP1 on chromosome 2q35. Four single base-pair polymorphisms (274 C/T, 469+14 G/C, 1465-85 G/A, and D543N), a (GT)(n) repeat in the promoter region of NRAMP1 and D2S1471, and a microsatellite marker approximately 130-kb downstream of NRAMP1 were examined. The allelic and genotypic frequencies for each polymorphism were compared in case patients and control subjects. No allelic association was identified between the NRAMP1 alleles and typhoid fever susceptibility. In addition, neither homozygotes nor heterozygotes for any NRAMP1 variants were at increased risk of typhoid fever.

Epidemic typhoid in vietnam: molecular typing of multiple-antibiotic-resistant Salmonella enterica serotype typhi from four outbreaks

Multidrug-resistant Salmonella enterica serotype Typhi isolates from four outbreaks of typhoid fever in southern Vietnam between 1993 and 1997 were compared. Pulsed-field gel electrophoresis, bacteriophage and plasmid typing, and antibiotic susceptibilities showed that independent outbreaks of multidrug-resistant typhoid fever in southern Vietnam are caused by single bacterial strains. However, different outbreaks do not derive from the clonal expansion of a single multidrug-resistant serotype Typhi strain.

Patient doses in abdominal aortogram and aorta femoral runoff examinations

Radiation doses to adult male patients from abdominal aortogram and aorta femoral runoff examinations in a medical center were determined with the help of a dose-area product meter. The abdominal aortogram and aorta femoral runoff examination consisted of scout radiographs, fluoroscopy (to position a catheter near the area of interest), and serial films (to record the flow of contrast media). Measurements were converted to effective doses with the help of published results from Monte Carlo simulation calculations. Data from 19 male adult patients weighing 53 to 86 kg were analyzed. The resulting total effective dose had a value of 14.0 +/- 4A mSv (mean and standard deviation). The percent contribution by fluoroscopy was 18.5 +/- 9.9%. The fluoroscopy effective dose had a stronger correlation with the dose-area product (correlation coefficient of 0.97) than with duration of exposure (correlation coefficient of 0.84). Most of the radiation exposure in the observed abdominal aortogram and aorta femoral runoff examination was attributed to radiography.

Entrance skin exposure in PA chest radiography

To determine whether entrance skin exposure during chest radiography is related to the thickness of the patient's chest, the authors used a dose-area product meter to record ESE during posteroanterior chest examinations of adult male patients. Manual adjustment of collimation and automatic exposure control were used. Analysis of the results showed a weak correlation between radiation exposure and chest thickness. The equivalent chest thicknesses of anthropomorphic phantoms are thinner than the chest thicknesses of most adult patients. Therefore, if it is necessary to measure the entrance skin exposure to a patient, it should be measured directly or computed from the actual technique used. An examination of the distribution of recorded dose-area product shows that this parameter can be a quality control criterion for limiting the field size in manual collimation.

The pattern of tuberculosis in Queen Elizabeth Central Hospital, Blantyre, Malawi: 1986-1995

SETTING

Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi.

OBJECTIVE

To determine the pattern of tuberculosis (TB) cases over a period of ten years.

DESIGN

TB registers for QECH for the years 1986-1995 (January 1st to December 31st) were obtained and clinical information on the type of TB in each patient was recorded. Human immunodeficiency virus (HIV) test results of adults with smear-positive pulmonary TB (PTB) and children with TB between 1993 and 1996 were recorded from case notes.

RESULTS

There were 19,377 TB cases, 10,982 men and 8,395 women, registered over the ten-year period. Of these, 4,691 (24%) cases were in children aged 0-14 years and 11,890 (61%) cases were in adults aged 15-44 years. The number of cases increased from 657 in 1986 to 2,734 in 1995, and the proportion of cases with extra-pulmonary TB (EPTB) rose from 11% in 1986 to 33% in 1995. The largest increase in cases was in children and in young adults aged 15-44 years. In all age groups, PTB was more common than EPTB. There were significant increases in the proportion of adult TB cases with pleural effusion. Of those who were tested, 72% of adults with smear-positive PTB and 64% of children with TB were found to be HIV-seropositive.

CONCLUSION

There has been a dramatic increase in cases of TB and changes in disease pattern in QECH during the last 10 years, which is related to the HIV epidemic.

Short courses of ofloxacin for the treatment of enteric fever

Typhoid fever continues to be a major public health problem in tropical countries, exacerbated in recent years by the spread of multi-drug resistant strains of Salmonella typhi. Short treatment courses of fluoroquinolones are effective, and have the advantage of reduced cost and increased compliance, but the optimal length of treatment is unknown. In an open, randomized comparison, 107 adults with uncomplicated enteric fever (95 of whom had positive blood cultures for S. typhi and 5 for S. paratyphi) were treated with oral ofloxacin, 15 mg/kg/d for 2 d or 10 mg/kg/d for 3 d. Mean fever clearance times were the same in the 2 treatment groups (97 h). There were 7 treatment failures, one in the 2 d group and 6 in the 3 d group (P = 0.07). Three of the 5 patients infected with nalidixic acid resistant strains of S. typhi had treatment failures, compared with 4 of 90 with nalidixic acid sensitive isolates (P < 0.0001; relative risk 13.5, 95% confidence interval 4.1-43%). Treatment with ofloxacin for 2 or 3 d is equally effective in adults with uncomplicated enteric fever caused by nalidixic acid sensitive strains of S. typhi. The epidemiology and management of nalidixic acid resistent typhoid needs further investigation.

Prevalence of psychiatric morbidity in the adult population of a rural South African village

We report on the first South African two-stage community prevalence study of psychiatric morbidity, conducted in Mamre, a rural "coloured' village, 50 km from Cape Town. Randomly selected adults (N = 481) were assessed using the Self-Reporting Questionnaire (SRQ) as a first-stage screen and the Present State Examination (PSE-9) was administered to a proportion of the sample (N = 121) as the second-stage criterion. Demographic, health care utilization, and substance abuse data were also collected. Using the PSE-9 CATEGO Index of Definition of 5, the weighted prevalence of psychiatric morbidity was 27.1% (confidence interval of 19.5-34.7%), the majority of cases being given a tentative diagnosis of depressive or anxiety disorder. The CATEGO algorithm may not be fully appropriate in this cultural context as there was an apparent over-diagnosis of paranoid states. The SRQ's weighted sensitivity and specificity were 0.49 and 0.82 respectively. Overall, the SRQ correctly identified 67% of cases and non-cases. No demographic variables predicted psychiatric morbidity, but there was an indirect link between morbidity and primary care utilization. Further South African studies of the validity of both the SRQ and of criterion instruments are needed. These may contribute to knowledge regarding cultural factors affecting psychiatric diagnosis.

Alcohol attributable fractions for trauma in South Africa

The misuse and abuse of alcohol is widespread in South African society and is likely to have a large impact on the economy. A major burden is borne by the hospital care system, in particular the cost of alcohol-related trauma. The purpose of this study was to estimate the cost of alcohol misuse in terms of fatal and non-fatal trauma. The design of the study was a cross-sectional survey of key informants. Each key informant was mailed a list of 11 trauma categories found to be linked to alcohol in both the local and international literature. They were asked to make an estimate of the alcohol attributable fraction (AAF) for each trauma category, based on their clinical experience and knowledge of empirical research. The median estimates for each trauma category showed that alcohol misuse could be linked to a substantial amount of mortality and morbidity, particularly with respect to motor vehicle trauma and interpersonal violence. These AAF estimates were supported by the findings of other empirical research conducted in South Africa, as well as by the literature on mortality data in the U.S.A. This suggests that there is potential for a vast amount of injuries and deaths to be eliminated if alcohol misuse could be controlled or eliminated.

Structural analysis of affinity maturation: the three-dimensional structures of complexes of an anti-nitrophenol antibody

Affinity maturation of the immune response to nitrophenol-containing antigens has been extensively investigated. Significant strides made during the past several years with the advent of PCR technology have provided a wealth of biochemical knowledge. Structural investigations of the phenomena have however been limited. We have determined the three-dimensional structure of the Fab fragment of 88C6/12, an anti-4-hydroxy-3-nitrophenyl acetic acid antibody complexed with the immunizing hapten and with a heteroclitic iodinated hapten. The crystallographic structure of the complexes reveals that the binding is stabilized by a number of hydrogen bonds and extensive van der Waals interactions between the hapten and the antibody. In addition, the Fab binding pocket contains a region of positive electrostatic potential well suited for interaction with the predominant resonance form of the nitrophenyl ring system. The observed heteroclicity towards the iodinated hapten is not a direct result of iodine-protein interactions, but results from the enhanced stability in the iodinated ring of the resonance form that binds the antibody. In addition this investigation provides a rationale for the strong preference for the substitution in the heavy chain from the germ-line gene encoded Trp 33 to Leu 33 in the mature anti-nitrophenol response.

Hyaluronic acid-filled mammary implants: an experimental study

Issues of radiolucency and biocompatibility of currently available mammary implants have prompted the search for alternatives. Several new filler materials have been suggested recently but have involved the use of materials foreign to the body. We have studied the use of a naturally found polysaccharide molecule, hyaluronic acid, as an alternative filler material to silicone gel. We tested hyaluronic acid-filled implants using standard mammographic techniques, applanation tonometry, and in an in vivo animal model (n = 24) up to 1 year after implantation. The present study demonstrates that hyaluronic acid-filled implants have softness comparable with that of silicone gel and saline implants and are more radiolucent, allowing better visualization of breast structures around the implant. Furthermore, in vivo studies fail to demonstrate any adverse reactions to the material over a period of 1 year. Hyaluronic acid has unique properties in modulating the process of wound healing, and these properties may be applied to the tissues surrounding the implants as a result of leaching of hyaluronic acid through the covering shell. Although further studies using larger volumes of filler, characterization of the hyaluronic acid within the implant, quantification of the exact amounts of hyaluronic acid leached into surrounding tissues, and a more appropriate primate model need to be undertaken, this pilot study points out that there may be more biologically compatible materials for the use in breast implants that warrant further investigation.

Production of long-lived neutralizing antibodies to HIV-1 IIIB in mice with a vaccinia recombinant virus-infected cell vaccine expressing gp160

A formaldehyde-fixed cell vaccine in adjuvant (syngeneic cells infected with a vaccinia virus recombinant expressing gp160: vacc-gp160) stimulated only nonneutralizing antibody when used on its own in four strains of mice, but a similar nonfixed cell vaccine stimulated neutralizing antibodies up to a titer of 1/320 in C57BL/6 (H-2b) mice previously infected with live vacc-gp160. Synthesis of ELISA antibodies to rgp120 or rgp160 did not correspond closely to the synthesis of neutralizing antibodies and should not therefore be used to monitor the production of neutralizing antibody. The ELISA antibody response produced by boosting with the cell vaccine made with the vaccinia virus expressing gp160 under the control of a T7 promoter (vacc-gp160-PT7) was as high as that in mice given an approximately 10-fold higher dose of purified rgp160. The ELISA antibody response to the cell vaccine made with vacc-gp160-PT7 was better than that in which gp160 was expressed under the vaccinia early/late promoter (vacc-gp160-P7.5). Nearly all mice (92%; 11 of 12) primed by infection with vacc-gp160 produced comparable levels of neutralizing antibodies after a single boost with rgp160, vacc-gp160-PT7-infected cells, or vacc-gp160-P7.5-infected cells. Neutralization titers peaked at around day 22 after boost, and declined by day 29. A second boost with the same vacc-gp160-infected cells gave increased neutralizing titers in all (eight of eight) mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Kohl: a lead-hazardous eye makeup from the Third World to the First World

Kohl is a widely used traditional cosmetic. It is mainly worn around the eyes in Asia, Africa, and the Middle East. It may be a pervasive source of lead poisoning in those areas and among individuals from those areas who have immigrated to developed nations. Samples of kohl were purchased in Morocco, Mauritania, Great Britain, and the United States. Some of these samples originated from Pakistan, India, and Saudi Arabia. Kohl is widely believed to consist of antimony, but analysis consistently revealed only trace amounts of antimony. Nine of the twenty-two samples tested contained less than 0.6% lead; however, seven samples had lead levels in excess of 50%. The remainder ranged from 3.31 to 37.3%. Third-world-manufactured kohls were purchased in the United States and Britain, suggesting that this hazard is no longer confined to the third world. Those kohls that contained lead were sold in violation of laws on lead in cosmetics in both of these nations. Third-world physicians and health care workers appear to be unaware of possible lead uptake from unsuspected traditionally used items. Physicians in developed nations with patients from Asia, the Middle East, and North Africa need to factor in the possibility of past or present lead intake from unorthodox sources such as kohl.

Pyridoxal 5'-phosphate deficiency in uremic undialyzed, hemodialyzed, and non-uremic kidney transplant patients

In this study, we have investigated plasma pyridoxal 5'-phosphate (PLP) concentrations in undialyzed and dialyzed uremic patients and in kidney transplant subjects, using an enzymatic technique with thermal deproteinization to liberate PLP from plasma proteins. The specificity of the reaction indicates no interference with pyridoxal and only 3% interference with pyridoxamine phosphate. In 17 hemodialyzed patients, a deficiency of about 50% of plasma PLP concentration is found as compared to 25 healthy subjects (22.2 +/- 2.47 vs. 48.8 +/- 3.00 nmol . l-1), as mean +/- SEM). In seven undialyzed uremic patients with end-stage renal failure, the plasma PLP concentration is also decreased (29.3 +/- 1.74 nmol . l-1). The absence of PLP in plasma ultrafiltrates demonstrates that no loss of PLP occurs due to hemodialysis. The daily oral supplementation with 250-750 mg pyridoxal induces a supraphysiological increase in plasma PLP concentration in hemodialyzed as well as in undialyzed patients. In 116 non-uremic kidney transplant subjects, the mean plasma PLP concentration was 33.8 +/- 3.50 nmol . l-1). In 65% of these patients, a marked deficit (below 20 nmol . l-1) was observed. In conclusion, uremic patients have a deficient vitamin B6 state. Its correction with pyridoxal to restore physiological plasma PLP concentration necessitates oral supplementation with lower doses that those widely used at present. In kidney transplant patients a similar plasma PLP deficiency is observed in the absence of chronic renal failure.