Ethical guidelines for deliberately infecting volunteers with COVID-19.

Global fatalities related to COVID-19 are expected to be high in 2020-2021. Developing and delivering a vaccine may be the most likely way to end the pandemic. If it were possible to shorten this development time by weeks or months, this may have a significant effect on reducing deaths. Phase II and phase III trials could take less long to conduct if they used human challenge methods-that is, deliberately infecting participants with COVID-19 following inoculation. This article analyses arguments for and against such methods and provides suggested broad guidelines for regulators, researchers and ethics committees when considering these matters. It concludes that it may be possible to maintain current ethical standards yet still permit human challenge trials in a context where delay is critical. The implications are that regulators and researchers need to work together now to design robust but short trials and streamline ethics approval processes so that they are in place when applications for trials are made.

Placental 11ß-Hydroxysteroid dehydrogenase type 2 expression: Correlations with birth weight and placental metal concentrations.

INTRODUCTION: Infants born below 2500 g are classified as low birth weight. Excess in utero exposure to cortisol has been linked to restricted fetal growth. Placental production of 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) inactivates cortisol before passage into the fetus. The present study tested the hypothesis that placental 11ß-HSD2 expression is positively correlated with an individualized birth weight centile and raw birth weight, and examines the relationship between metal concentrations in placental tissue and 11ß-HSD2 expression. METHODS: Placentae from 191 births were collected and samples preserved to maintain mRNA profile. Placental 11ß-HSD2 expression was measured via qRT-PCR. Addition samples were collected from placental tissues and uniformly dried in order to quantify 18 metals via ICP-MS (n = 160). RESULTS: A significant, positive correlation between 11ß-HSD2 expression and individualized birth weight centile (p = 0.0321) and birth weight (p = 0.0243) was found. Additionally, maternal age and gestational age were positivity correlated with each other (p = 0.0321). Birth weight was significantly different with race, marital status, education and maternal tobacco use. Four metals (Co, Mn, Ni, Zn) demonstrated significant positive correlations (p < 0.05) with 11ß-HSD2 expression. Sex specific differences were found; Co, Cu, Fe, Zn, and Ni were positively correlated with 11ß-HSD2 expression in males only, no significant correlations were found in the female only sample. CONCLUSION: These data indicate that the growth potential of a fetus is related to the 11ß-HSD2 expression in the placenta, and that 11ß-HSD2 expression is related to the trace metals status of the mother.

Placental concentrations of bisphenol A and birth weight from births in the Southeastern U.S.

INTRODUCTION: Bisphenol A (BPA) is a weakly estrogenic compound that has been detected in a wide variety of food products and biological matrices (saliva, blood, urine, etc). Despite the potential risk of human exposure to BPA, little information exists concerning maternal and fetal exposure to BPA during pregnancy. The aim of this study is to evaluate the correlation between placental BPA concentration, infant birth weight and calculated birth weight centile, and several other maternal and infant parameters. METHODS: Placental sample were collected from 200 subjects. BPA levels were measured by isotope dilution GC-MS. Additional maternal and infant data were gathered from medical charts and were potential correlates with placental BPA levels. RESULTS: Placental BPA concentrations ranged from 4.4 ng/g to 273.9 ng/g in oven-dried tissue (average 103.4 ± 61.8 ng/g). There was a significant negative correlation between calculated birth weight centile and levels of placental BPA (p < 0.05). Low birth weight and small for gestational age infants also had significantly greater placental BPA concentrations as compared to normal weight infants and average/large for gestational age infants. Infants born to African American mothers also had greater placental BPA concentrations as compared to infants born to Hispanic mothers. DISCUSSION: Placental BPA concentrations are correlated with the growth potential of the fetus and may play a role in reduced fetal growth.

PP087. Deep trial secondary analysis: Digoxin immune fab fragment treatment has additional benefits in endogenous digitalis-like factor positive preeclamptic women.

INTRODUCTION: A double blinded placebo controlled clinical trial of a commercial digoxin immune Fab fragment (DIF) in preeclamptic (PE) women provided some benefit to treated subjects (1). In that study DIF, relative to placebo, prevented a decline in CrCl and lowered levels of endogenous digitalis-like factor (EDLF) activity as measured by sodium pump inhibition (SPI). However, some PE subjects had undetectable EDLF. OBJECTIVES: The hypothesis tested was that only PE women with measureable EDLF would respond to DIF treatment and analysis of EDLF positive women might reveal treatment effects masked by inclusion of EDLF negative, and hence non-responding, PE women. Accordingly, analyses of DIF effects in EDLF positive PE women were conducted. METHODS: Patient characteristics and study design have been published (1). In these subanalyses, subjects were considered to be EDLF positive if their plasma inhibited red cell sodium pump mediated Rb uptake. All analyses were redone for the EDLF positive subgroup by Covance Inc as in the original trial. Continuous data were analyzed by ANCOVA. Categorical data were analyzed by Barnard Exact Test. RESULTS: 45 subjects (23 DIF, 22 placebo) had baseline SPI evaluated. Of these 22% had undetectable SPI. EDLF positive PE women showed greater and more significant reductions of SPI in response to DIF at each time point (12, 24, 48 hr treatment) than in the original analysis. Subjects with undetectable EDLF showed no significant change in response to DIF or placebo. For CrCl, EDLF positive PE women showed greater and more significant preservation of CrCl compared with original analyses. Subjects absent EDLF showed deterioration of CrCl with or without DIF. Among EDLF positive PE women DIF treated women had significantly less maternal pulmonary edema (p=0.035) and significantly less intraventricular hemorrhage in their infants (p=0.015). There was the suggestion of reductions in the incidence of other maternal and neonatal abnormalities. CONCLUSION: These data indicate that EDLF positive PE women are those that responded to DIF and also raise the possibility of extended benefits of DIF treatment in this group. Results support further research in this area.

Antimicrobial activity of ruthenium-based intercalators.

Multidrug resistance of bacterial pathogens is a major problem and there is a clear need for the development of new types of antibiotics. Here we investigated the antimicrobial activity of ruthenium(II) based DNA-intercalating complexes. These complexes were found to have no activity in vitro against the Gram-negative bacterium Escherichia coli, but the complexes were clearly active against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus. In vivo activity has also been demonstrated for one of the compounds using a simple infection model, the nematode Caenorhabditis elegans. Importantly, this also showed that the compound tested was not toxic to the nematodes.

Antimicrobial activity of an iron triple helicate.

The prevalence of antibiotic resistance has resulted in the need for new approaches to be developed to combat previously easily treatable infections. Here we investigated the potential of the synthetic metallomolecules [Fe(2)L(3)](4+) and [Cu(2)(L')(2)](2+) as antibacterial agents. Both molecules have been shown to bind DNA; [Fe(2)L(3)](4+) binds in the major groove and causes DNA coiling, whilst [Cu(2)(L')(2)](2+) can act as an artificial nuclease. The work described here shows that only [Fe(2)L(3)](4+) is bactericidal for Bacillus subtilis and Escherichia coli. We demonstrate that [Fe(2)L(3)](4+) binds bacterial DNA in vivo and, strikingly, that it kills B. subtilis cells very rapidly.

Synthetic metallomolecules as agents for the control of DNA structure.

This tutorial review summarises B-DNA structure and metallomolecule binding modes and illustrates some DNA structures induced by molecules containing metallic cations. The effects of aquated metal ions, cobalt amines, ruthenium octahedral metal complexes, metallohelicates and platinum complexes such as cis-platin are discussed alongside the techniques of NMR, X-ray crystallography, gel electrophoresis, circular dichroism, linear dichroism and molecular dynamics. The review will be of interest to people interested in both DNA structure and roles of metallomolecules in biological systems.

Diversity in a variable-number tandem repeat from Yersinia pestis.

We have identified a tetranucleotide repeat sequence, (CAAA)(N), in the genome of Yersinia pestis, the causative agent of plague. This variable-number tandem repeat (VNTR) region has nine alleles and great diversity (calculated as 1 minus the sum of the squared allele frequencies) (diversity value, 0.82) within a set of 35 diverse Y. pestis strains. In contrast, the nucleotide sequence of the lcrV (low-calcium-response) gene differed only slightly among these strains, having a haplotype diversity value of 0.17. Replicated cultures, phenotypic variants of particular strains, and extensively cultured replicates within strains did not differ in VNTR allele type. Thus, while a high mutation rate must contribute to the great diversity of this locus, alleles appear stable under routine laboratory culture conditions. The classic three plague biovars did not have single identifying alleles, although there were allelic biases within biovar categories. The antiqua biovar was the most diverse, with four alleles observed in 5 strains, while the orientalis and mediaevalis biovars exhibited five alleles in 21 strains and three alleles in 8 strains, respectively. The CAAA VNTR is located immediately adjacent to the transcriptional promoters for flanking open reading frames and may affect their activity. This VNTR marker may provide a high-resolution tool for epidemiological analyses of plague.

Splenic rupture associated with severe preeclampsia. A case report.

BACKGROUND: Splenic rupture is a very rare event complicating pregnancy. Approximately 5% of cases reported have involved the postpartum period. Unrecognized, this complication is universally fatal. CASE: Preeclampsia and pulmonary edema complicated a 42-year-old woman's intrapartum care. After cesarean delivery she was supported with mechanical ventilation, blood products and invasive monitoring. Shortly thereafter, she became hypotensive and developed disseminated intravascular coagulation. During exploratory laparotomy a splenic capsular rupture was identified. Splenectomy and continued intensive care support ultimately reversed the severe end-organ consequences. CONCLUSION: It is extremely important that this condition be maintained in the diagnostic differential of post-operative hemodynamic instability. Failure to identify it is invariably fatal. Awareness and intervention are essential to ensure a good outcome.

PCR analysis of tissue samples from the 1979 Sverdlovsk anthrax victims: the presence of multiple Bacillus anthracis strains in different victims.

An outbreak of human anthrax occurred in Sverdlovsk, Union of Soviet Socialists Republic (now Ekaterinburg, Russia) in April 1979. Officials attributed this to consumption of contaminated meat, but Western governments believed it resulted from inhalation of spores accidentally released from a nearby military research facility. Tissue samples from 11 victims were obtained and methods of efficiently extracting high-quality total DNA from these samples were developed. Extracted DNA was analyzed by using PCR to determine whether it contained Bacillus anthracis-specific sequences. Double PCR using "nested primers" increased sensitivity of the assay significantly. Tissue samples from 11 persons who died during the epidemic were examined. Results demonstrated that the entire complement of B. anthracis toxin and capsular antigen genes required for pathogenicity were present in tissues from each of these victims. Tissue from a vaccination site contained primarily nucleic acids from a live vaccine, although traces of genes from the infecting organisms were also present. PCR analysis using primers that detect the vrrA gene variable region on the B. anthracis chromosome demonstrated that at least four of the five known strain categories defined by this region were present in the tissue samples. Only one category is found in a single B. anthracis strain.

Characterization of the variable-number tandem repeats in vrrA from different Bacillus anthracis isolates.

PCR analysis of 198 Bacillus anthracis isolates revealed a variable region of DNA sequence differing in length among the isolates. Five polymorphisms differed by the presence of two to six copies of the 12-bp tandem repeat 5'-CAATATCAACAA-3'. This variable-number tandem repeat (VNTR) region is located within a larger sequence containing one complete open reading frame that encodes a putative 30-kDa protein. Length variation did not change the reading frame of the encoded protein and only changed the copy number of a 4-amino-acid sequence (QYQQ) from 2 to 6. The structure of the VNTR region suggests that these multiple repeats are generated by recombination or polymerase slippage. Protein structures predicted from the reverse-translated DNA sequence suggest that any structural changes in the encoded protein are confined to the region encoded by the VNTR sequence. Copy number differences in the VNTR region were used to define five different B. anthracis alleles. Characterization of 198 isolates revealed allele frequencies of 6.1, 17.7, 59.6, 5.6, and 11.1% sequentially from shorter to longer alleles. The high degree of polymorphism in the VNTR region provides a criterion for assigning isolates to five allelic categories. There is a correlation between categories and geographic distribution. Such molecular markers can be used to monitor the epidemiology of anthrax outbreaks in domestic and native herbivore populations.

Molecular evolution and diversity in Bacillus anthracis as detected by amplified fragment length polymorphism markers.

Bacillus anthracis causes anthrax and represents one of the most molecularly monomorphic bacteria known. We have used AFLP (amplified fragment length polymorphism) DNA markers to analyze 78 B. anthracis isolates and six related Bacillus species for molecular variation. AFLP markers are extremely sensitive to even small sequence variation, using PCR and high-resolution electrophoresis to examine restriction fragments. Using this approach, we examined ca. 6.3% of the Bacillus genome for length mutations and ca. 0.36% for point mutations. Extensive variation was observed among taxa, and both cladistic and phenetic analyses were used to construct a phylogeny of B. anthracis and its closest relatives. This genome-wide analysis of 357 AFLP characters (polymorphic fragments) indicates that B. cereus and B. thuringiensis are the closest taxa to B. anthracis, with B. mycoides slightly more distant. B. subtilis, B. polymyxa, and B. stearothermophilus shared few AFLP markers with B. anthracis and were used as outgroups to root the analysis. In contrast to the variation among taxa, only rare AFLP marker variation was observed within B. anthracis, which may be the most genetically uniform bacterial species known. However, AFLP markers did establish the presence or absence of the pXO1 and pXO2 plasmids and detected 31 polymorphic chromosomal regions among the 79 B. anthracis isolates. Cluster analysis identified two very distinct genetic lineages among the B. anthracis isolates. The level of variation and its geographic distribution are consistent with a historically recent African origin for this pathogenic organism. Based on AFLP marker similarity, the ongoing anthrax epidemic in Canada and the northern United States is due to a single strain introduction that has remained stable over at least 30 years and a 1,000-mile distribution.

Sideswipe elbow fractures.

A retrospective review of all cases of sideswipe elbow fractures (SSEFs) treated at two community hospitals from 1982 to 1992 was conducted to determine the functional outcome of the operative treatment of SSEFs. All five injuries involved the left elbow, and they included open fractures of the olecranon, the radius and ulna, the ulna and humerus, the humerus, and traumatic amputation of the arm. Concomitant injuries included three radial nerve palsies and two injuries each to the median nerve, ulnar nerve, and brachial artery. Treatment included irrigation, debridement (repeated if necessary), open reduction and internal fixation, external fixation (one case), and delayed amputation (one case). An average of 130/-10 degrees elbow flexion/extension, and 60/60 degrees supination/pronation was obtained for the three of four patients with reconstructions who returned for follow-up.

Clozapine use in female geriatric patients with psychoses.

This study was undertaken to evaluate the clinical response of geriatric patients with psychoses to the atypical neuroleptic drug, clozapine. Records of patients over 60 years of age (n = 12, all female) who had received clozapine over a 30-month period from selected hospitals in Western Pennsylvania were reviewed. Among the six patients who were rapidly titrated (300 mg/day in 3 weeks), none are currently receiving clozapine, while four patients who received a slower titration and lower dosage (range, 25 mg/day to 300 mg/day; mean, 150 mg/day) remain clinically improved on stable doses of clozapine. Postural hypotension affected seven patients, and was the reason for discontinuation of clozapine in five patients. One patient experienced nonfatal agranulocytosis, and one subject experienced leukopenia. One patient died from causes unrelated to clozapine. This retrospective study suggests both a low-dose and slow-titration strategy for initiating clozapine among elderly patients, similar to the use of other psychotropic drugs in the elderly, as well as close attention to postural hypotension, agranulocytosis, and drug interactions.

Displacement of an uncemented acetabular component after dislocation of a total hip prosthesis. A case report.

Review of the literature reveals few reports of complications encountered with noncemented acetabular components; most concern problems with screw or cup placement, component wear or migration, or disassembly of modular components. No reports involving the displacement of a noncemented acetabular component were found. This is a case report of a patient in whom a noncemented acetabular component was dislodged after the closed reduction of a dislocated total hip prosthesis 4.5 weeks after surgery. In light of this case, the authors believe these reductions should be performed under general anesthesia with fluoroscopic guidance. Care must be taken at surgery to ream sufficiently and obtain proper cup fit and position. Finally, the authors recommend bicortical screw fixation to provide maximum contact and rigid fixation in the early postoperative period.

Pathologic fractures of the humerus.

In a study of 57 actual or impending pathologic fractures of the humerus in 52 patients with inoperable cancer treated between 1972 and 1982, we retrospectively reviewed the charts for analysis and comparison of the functional result and pain relief afforded by the various treatments used. Function of the extremity and relief of pain were each graded as excellent, good, fair, or poor using a modification of Perez's rating system. Seven pathologic fractures were treated nonoperatively. These patients generally had only fair pain relief and a poor functional result. Forty-six pathologic fractures were treated with intramedullary fixation using a Rush rod (n = 16), a Küntscher rod (n = 29), or an Ender rod (n = 1); the Neer endoprosthesis was used in four patients. Thirty-one patients received radiation to the humerus. There were seven operative complications, the most common (n = 3) being prominence of an intramedullary rod at the insertion site which required a second minor procedure for advancement of the rod. From this series, we conclude that any patient who has a pathologic fracture or impending fracture of the humerus and a predicted survival of six weeks or more is likely to benefit from rigid internal fixation with an appropriately selected device, adjunctive use of methylmethacrylate, and postoperative local irradiation therapy as needed.

Medial synovial shelf plica syndrome. Treatment by intraplical steroid injection.

Medial synovial shelf plica syndrome is caused by acquired thickening and inflammation of a commonly present residual embryonic synovial fold. Treatment with a local injection into the plica and surrounding synovium of a steroid and a long-acting local anesthetic was tested in a series of 30 patients to see if more involved and expensive treatment could be avoided. Thirty-one knees were studied and treated prospectively; rigid criteria for making the diagnosis were maintained. Twenty-two (73%) patients had complete relief of pain and full return to activity; five patients had some amelioration of their symptoms and partial return to activity; and three patients had poor results. Two of the poor results were secondary to errors in diagnosis, and one was secondary to the presence of mature fibrosis confirmed during subsequent arthroscopic resection. As a control, ten patients were injected with long-acting local anesthetic alone. In all ten, symptoms were relieved only for the duration of the anesthetic. Intraplical steroid injection appears to be a reasonable, prudent, initial step in the treatment of medial synovial shelf plica syndrome. For competitive athletes, it provides very short morbidity and the ability to return to full practice and participation in a very short period of time.