Biochar influences nitrogen and phosphorus dynamics in two texturally different soils

Nitrogen (N) and phosphorus (P) are vital for crop growth. However, most agricultural systems have limited inherent ability to supply N and P to crops. Biochars (BCs) are strongly advocated in agrosystems and are known to improve the availability of N and P in crops through different chemical transformations. Herein, a soil-biochar incubation experiment was carried out to investigate the transformations of N and P in two different textured soils, namely clay loam and loamy sand, on mixing with rice straw biochar (RSB) and acacia wood biochar (ACB) at each level (0, 0.5, and 1.0% w/w). Ammonium N (NH4-N) decreased continuously with the increasing incubation period. The ammonium N content disappeared rapidly in both the soils incubated with biochars compared to the unamended soil. RSB increased the nitrate N (NO3-N) content significantly compared to ACB for the entire study period in both texturally divergent soils. The nitrate N content increased with the enhanced biochar addition rate in clay loam soil until 15 days after incubation; however, it was reduced for the biochar addition rate of 1% compared to 0.5% at 30 and 60 days after incubation in loamy sand soil. With ACB, the net increase in nitrate N content with the biochar addition rate of 1% remained higher than the 0.5% rate for 60 days in clay loam and 30 days in loamy sand soil. The phosphorus content remained consistently higher in both the soils amended with two types of biochars till the completion of the experiment.

Nanodiamonds enable femtosecond-processed ultrathin glass as a hybrid quantum sensor

The quantum properties of fluorescent nanodiamonds offer great promise for fabricating quantum-enabled devices for physical applications. However, the nanodiamonds need to be suitably combined with a substrate to exploit their properties. Here, we show that ultrathin and flexible glass (thickness 30 microns) can be functionalized by nanodiamonds and nano-shaped using intense femtosecond pulses to design cantilever-based nanomechanical hybrid quantum sensors. Thus fabricated ultrathin glass cantilevers show stable optical, electronic, and magnetic properties of nitrogen-vacancy centers, including well-defined fluorescence with zero-phonon lines and optically detected magnetic resonance (ODMR) near 2.87 GHz. We demonstrate several sensing applications of the fluorescent ultrathin glass cantilever by measuring acoustic pulses, external magnetic field using Zeeman splitting of the NV centers, or CW laser-induced heating by measuring thermal shifting of ODMR lines. This work demonstrates the suitability of the femtosecond-processed fluorescent ultrathin glass as a new versatile substrate for multifunctional quantum devices.

Effects of anterior maxillary distraction compared to LeFort-1 osteotomy and total maxillary distraction osteogenesis for treating hypoplastic maxilla in patients with cleft lip and palate- A systematic review and meta-analysis

OBJECTIVE

To compare the treatment outcomes and effectiveness of Anterior Maxillary Distraction (AMD) with the LeFort I Osteotomy and Total Maxillary Distraction Osteogenesis (TMDO) to treat cleft maxillary hypoplasia.

METHODS

(PROSPERO CRD42020223345) Thorough electronic search of seven databases, unpublished gray literature, and a hand search of the relevant studies reference lists was done. Studies assessing mid-facial skeletal, dentoalveolar, and soft-tissue outcomes of AMD in patients >8 years of age, hypoplastic cleft maxilla, and with either TMDO/LeFort 1/ both as control groups were included. Seven included articles were assessed for the study characteristics and qualitative synthesis. Three studies were analyzed quantitatively using the RevMan 5.4 software. The quality of studies was assessed using Cochrane ROB2 and the overall certainty of evidence using GRADE.

RESULTS

AMD was performed in 241 subjects, LeFort 1 in 145 subjects, and TMDO in 42 subjects. Maxillary advancement for AMD and LeFort 1 groups showed no statistically significant difference (Mean Difference, MD -0.64°) while TMDO showed statistically significant advancement than AMD (MD -1.44°). Statistically significant upward rotation of anterior maxilla was noted with AMD (MD -6.15 degrees) than Lefort 1. Upper incisor inclination improved in both AMD and TMDO groups (MD 1.5°). Improvement in the maxilla-mandibular relationship, convexity of face, lip and nose, and marked dentoalveolar changes in overjet and upper incisor position were noted in all the three groups. Discernible airway alterations were noted in LeFort 1 and TMDOs. Total relapse was the least with AMD.

CONCLUSION

Distraction osteogenesis exhibited better dento-skeletal outcomes and minor skeletal relapse than LeFort 1. TMDO is a preferred modality in treating severe maxillary hypoplasia associated with CLP than AMD. Further long-term prospective comparative studies are required, possibly involving the patient-centric merits.

“A Century of Orthodontic Progress” – Innovations in Orthodontics

Innovation is the roadmap towards improvement .Creation, implementation and execution of new ideas, methods and technology aiming at efficiency and improvement is known as innovation. Innovation is the roadmap towards improvement. The speciality of orthodontics has obtained new dimensions due to innovations such as holistic orthodontic approach, Laser assisted orthodontics, digitization in diagnosis and treatment planning, nanotechnology, genetically driven orthodontic treatment plans with gene therapy, interactive self ligating bracket and flash free adhesive coated appliance system, robotic wire bending, 3D bioprinted scaffolds to treat osseous defects of the craniofacial complex, forensic orthodontics, mobile apps in orthodontics and dentoalveolar distraction modalities. These innovations have lead to an accurate treatment with reduced clinician efforts, enhanced treatment precision and better patient compliance. The future of orthodontic speciality with these adjunts is bright and progressive. With reduced clinician’s efforts and improved patient’s compliance these advancement are certainly a boon to our orthodontic speciality

In-line ultra-thin attosecond delay line with direct absolute-zero delay reference and high stability

We introduce an ultra-thin attosecond optical delay line based on controlled wavefront division of a femtosecond infrared pulse after transmission through a pair of micrometer-thin glass plates with negligible dispersion effects. The time delay between the two pulses is controlled by rotating one of the glass plates from absolute zero to several optical cycles, with 2.5 as to tens of attosecond resolution with 2 as stability, as determined by interferometric self-calibration. The performance of the delay line is validated by observing attosecond-resolved oscillations in the yield of high harmonics induced by time delayed infrared pulses, in agreement with a numerical simulation for a simple model atom. This approach can be extended in the future for performing XUV-IR attosecond pump-probe experiments.

Prosthetic fungal infections: poor prognosis with bacterial co-infection

AIMS

The aims of this study were to report the efficacy of revision surgery for patients with co-infective bacterial and fungal prosthetic joint infections (PJIs) presenting to a single institution, and to identify prognostic factors that would guide management.

PATIENTS AND METHODS

A total of 1189 patients with a PJI were managed in our bone infection service between 2006 and 2015; 22 (1.85%) with co-infective bacterial and fungal PJI were included in the study. There were nine women and 13 men, with a mean age at the time of diagnosis of 64.5 years (47 to 83). Their mean BMI was 30.9 kg/m² (24 to 42). We retrospectively reviewed the outcomes of these PJIs, after eight total hip arthroplasties and 14 total knee arthroplasties. The mean clinical follow-up was 4.1 years (1.4 to 8.8).

RESULTS

The median number of risk factors for PJI was 5.5 (interquartile range (IQR) 3.25 to 7.25). All seven patients who initially underwent debridement and implant retention (DAIR) had a recurrent infection that led to a staged revision. All 22 patients underwent the first of a two-stage revision. None of the nine patients with negative tissue cultures at the second stage had a recurrent infection. The rate of recurrent infection was significantly higher in the presence of multidrug-resistant bacteria (p = 0.007), a higher C-reactive protein (CRP) at the time of presentation (p = 0.032), and a higher number of co-infective bacterial organisms (p = 0.041). The overall rate of eradication of infection after two and five years was 50% (95% confidence interval (CI) 32.9 to 75.9) and 38.9% (95% CI 22.6 to 67), respectively.

CONCLUSION

The risk of failure to eradicate infection with the requirement of amputation associated with this diagnosis is much higher than in patients with PJI without bacterial and fungal co-infection, and this risk is heightened when the fungal organism is joined by polymicrobial and multidrug-resistant bacterial organisms. Cite this article: Bone Joint J 2019;101-B:582-588.

Time-resolved nano-Newton force spectroscopy in air and vacuum using a load cell of ultra micro-balance

We demonstrate a simple and versatile nanomechanical force measuring setup with 1 nN precision in air and vacuum using a load cell of an ultra-microbalance. We validate stability, precision, and linearity of the load cell with simple tests. The setup is customized to measure stress-strain response of biomaterials (silk, leaf, and flower) and capillary force in fluids. We isolated an optical pull force induced by a Watt-level laser reflected from a mirror/solid surface in air, in addition to optical push force. Furthermore, we add an interferometric probe to directly measure nanoscale deflection of cantilever of the load cell in real-time, thus bypassing its conventional electromagnetic readout, to improve speed and precision of the instrument. We demonstrate nanomechanical force measurement in high vacuum with the same precision and employ radiation pressure to calibrate the load cell for various precision measurements.

Systematic review of the effectiveness of community-based self-management interventions among primary care COPD patients

COPD self-management reduces hospital admissions and improves health-related quality of life (HRQoL). However, whilst most patients are managed in primary care, the majority of self-management trials have recruited participants with more severe disease from secondary care. We report the findings of a systematic review of the effectiveness of community-based self-management interventions in primary care patients with COPD. We systematically searched eleven electronic databases and identified 12 eligible randomised controlled trials with seven included in meta-analyses for HRQoL, anxiety and depression. We report no difference in HRQoL at final follow-up (St George's Respiratory Questionnaire total score -0.29; 95%CI -2.09, 1.51; I2 0%), nor any difference in anxiety or depression. In conclusion, supported self-management interventions delivered in the community to patients from primary care do not appear to be effective. Further research is recommended to identify effective self-management interventions suitable for primary care populations, particularly those with milder disease.

The processing and heterostructuring of silk with light

Spider silk is a tough, elastic and lightweight biomaterial, although there is a lack of tools available for non-invasive processing of silk structures. Here we show that nonlinear multiphoton interactions of silk with few-cycle femtosecond pulses allow the processing and heterostructuring of the material in ambient air. Two qualitatively different responses, bulging by multiphoton absorption and plasma-assisted ablation, are observed for low- and high-peak intensities, respectively. Plasma ablation allows us to make localized nanocuts, microrods, nanotips and periodic patterns with minimal damage while preserving molecular structure. The bulging regime facilitates confined bending and microwelding of silk with materials such as metal, glass and Kevlar with strengths comparable to pristine silk. Moreover, analysis of Raman bands of microwelded joints reveals that the polypeptide backbone remains intact while perturbing its weak hydrogen bonds. Using this approach, we fabricate silk-based functional topological microstructures, such as Mobiüs strips, chiral helices and silk-based sensors.

Selective disruption of vascular endothelium of zebrafish embryos by ultrafast laser microsurgical treatment

In this work, we demonstrate that ultrafast laser irradiation could selectively disrupt vascular endothelium of zebrafish embryos in vivo. Ultrafast lasers minimize the collateral damage in the vicinity of the laser focus and eventually reduce coagulation in the tissues. We have also found that the threshold fluence for lesion formation of the vascular endothelium strongly depends on the developmental stage of the embryos. The threshold laser fluence required to induce apparent lesions in the vascular structure for Somite 14, 20 and 25 stages is about 5 J/cm(2) ~7 J/cm(2), which is much lower than that for the later development stages of Prim 16 and Prim 20 of 30 J/cm(2) ~50 J/cm(2). The proposed method for treating the vascular cord of zebrafish embryos in the early stage of development has potential as a selective and effective method to induce a fatal lesion in the vascular endothelium without damaging the developed blood vessels.

Dynamic changes in PDMS surface morphology in femtosecond laser treatment

We have investigated the effect of the dynamics of crater size on the poly(dimethylsiloxane) (PDMS) surface morphology in fs-laser micro-processing. PDMS surface was processed with varying both inter-pulse interval and inter-spot distance between successive laser pulses. With keeping the interval of 5 ms crater shape is round even if the spot is overlapped in space. But decreasing the interval to 0.02 ms the shape of the crater is no longer round. Decreasing the inter-distance between the craters results in roughened surface morphology even at time intervals of 5 ms. Temporal dependence of single-shot fs-laser induced crater size was measured as a function of time delay. Within 0.1 ms after pulse irradiation with a fluence of 4.8 J/cm2 on PDMS surface the crater size has reached to its maximum values and then decreased with a time constant of about 0.3 ms. The surface morphology after fs-laser pulse irradiation is strongly dependent on not only inter-spot distance between successive laser pulse but also their inter-pulse intervals. By proposing a theoretical model on their dynamic features, we will try to explain the current observation in quantitatively.

Femtosecond laser-assisted selective reduction of neovascularization in rat cornea

Nonlinear multiphoton absorption induced by focusing near infrared (NIR) femtosecond (fs) laser pulses into a transparent cornea allows surgery on neovascular structures with minimal collateral damage. In this report, we introduce an fs laser-based microsurgery for selective treatment of rat corneal neovascularizations (in vivo). Contiguous tissue effects are achieved by scanning a focused laser pulse below the corneal surface with a fluence range of 2.2–8.6 J/cm². The minimal visible laser lesion (MVL) threshold determined over the corneal neovascular structures was found to be 4.3 J/cm². Histological and optical coherence tomography examinations of the anterior segment after laser irradiations show localized degeneration of neovascular structures without any unexpected change in adjacent tissues. Furthermore, an approximately 30 % reduction in corneal neovascularizations was observed after 5 days of fs laser exposure. The femtosecond laser is thus a promising tool for minimally invasive intrastromal surgery with the aid of a significantly smaller and more deterministic photodisruptive energy threshold for the interaction between the fs laser pulse and corneal neovascular structures.

Impact of myocardial ischemia on myocardial revascularization in stable ischemic heart disease. Lessons from the COURAGE and FAME 2 trials

In patients with stable ischemic heart disease (SIHD), myocardial revascularization should be performed to either improve survival or improve symptoms and functional status among patients who are not well controlled with optimal medical therapy (OMT). A general consensus exists on the core elements of OMT, which include both lifestyle intervention and intensive secondary prevention with proven pharmacotherapies. By contrast, however, there is less general agreement as to what constitutes the optimal approach to revascularization in SIHD patients. The COURAGE and FAME 2 randomized trials form the foundation of the current clinical evidence base and raise the important question: "What is the impact of myocardial ischemia on myocardial revascularization in stable ischemic heart disease?"

Effects of post-processing treatments on sensory quality and Shiga toxigenic Escherichia coli reductions in dry-fermented sausages

The effects of post-processing treatments on sensory quality and reduction of Shiga toxigenic Escherichia coli (STEC) in three formulations of two types of dry-fermented sausage (DFS; salami and morr) were evaluated. Tested interventions provided only marginal changes in sensory preference and characteristics. Total STEC reductions in heat treated DFS (32°C, 6days or 43°C, 24h) were from 3.5 to >5.5 log from production start. Storing of sausages (20°C, 1month) gave >1 log additional STEC reduction. Freezing and thawing of sausages in combination with storage (4°C, 1month) gave an additional 0.7 to 3.0 log reduction in STEC. Overall >5.5 log STEC reductions were obtained after storage and freezing/thawing of DFS with increased levels of glucose and salt. This study suggests that combined formulation optimisation and post-process strategies should be applicable for implementation in DFS production to obtain DFS with enhanced microbial safety and high sensory acceptance and quality.

Evaluation of fluoride varnish and its comparison with pumice prophylaxis using self-etching primer in orthodontic bonding--an in vivo study

The aim of this study was to evaluate the use of fluoride varnish as a prophylaxis method with self etching primer (SEP) and its comparison with pumice before orthodontic bonding. Thirty seven orthodontic patients participated in a prospective clinical trial. A split mouth technique was used in each patient, one quadrant was assigned to fluoride varnish and the contralateral quadrant to pumice prophylaxis. A total of 684 teeth were bonded with SEP (Transbond plus; 3M Unitek) and monitored for 6 months for bond failures. A total of 42 (6.1%) failures were recorded, 9 (2.6%) in the pumice group and 33 (9.6%) in the fluoride varnish group. Chi-square analysis was used to compare the number of bracket failures between the pumice and fluoride varnish groups and the number of patients in each group experiencing at least one bond failure. Statistically significant differences were found both in total number of bond failures (P < 0.001) and in the number of patients with bond failures (P < 0.05) between both groups. A significantly lower and clinically acceptable bond failure rate was observed with Transbond Plus self etching primer after pumice prophylaxis.

Polyclonal Antibodies in Renal Transplantation—A Relook

Polyclonal antibodies have been used in renal transplantation for the past four decades. Increasing knowledge regarding their varied mechanisms of action have confirmed their versatility in clinical practice. They can be used for induction, reversing acute rejections (especially those resistant to steroids), and possibly conferring an element of allotolerance, thereby reducing chronic allograft nephropathy. Their recent usage as IV bolus, single-dose, preoperative infusion as induction therapy in renal transplantation is an attractive and extremely cost-effective strategy, especially in a developing country such as India.

Organization of the antiseptic resistance gene qacA and Tn552-related beta-lactamase genes in multidrug- resistant Staphylococcus haemolyticus strains of animal and human origins

A part (12 kb) of a plasmid containing the beta-lactamase genes of Tn552, the disinfectant resistance gene qacA, and flanking DNA has been cloned from a Staphylococcus haemolyticus isolate and sequenced. This region was used to map the corresponding regions in six other multiresistant S. haemolyticus isolates of human and animal origin. The organizations of the genetic structures were almost identical in all isolates studied. The beta-lactamase and qacA genes from S. haemolyticus have >99.9% identities at the nucleotide level with the same genes from S. aureus, demonstrating that various staphylococcal species able to colonize animal and human hosts can exchange the genetic elements involved in resistance to antibiotics and disinfectants. The use of antibiotics and disinfectants in veterinary practice and animal husbandry may also contribute to the selection and maintenance of resistance factors among the staphylococcal species. Different parts of the 12-kb section analyzed had high degrees of nucleotide identity with regions from several other different Staphylococcus aureus plasmids. This suggests the contribution of interplasmid recombination in the evolutionary makeup of this 12-kb section involving plasmids that can intermingle between various staphylococcal species. The lateral spread of resistance genes between various staphylococcal species is probably facilitated by the generation of large multiresistance plasmids and the subsequent interspecies exchange of them.

Genetic linkage between resistance to quaternary ammonium compounds and beta-lactam antibiotics in food-related Staphylococcus spp

Little is known about the occurrence of antimicrobial resistance determinants in staphylococci isolated from food and food processing industries. Quaternary ammonium compound (QAC)-resistant coagulase-negative staphylococci (CNS) isolated from food and food-processing industries were investigated for the presence of genetic determinants (qacA/B and qacC/smr) encoding resistance to the QAC benzalkonium chloride (BC), several antibiotic resistance genes, and staphylococcal insertion sequences IS257 and IS256. Six qacA/B-harboring strains were resistant to penicillin and hybridized to a blaZ probe. The qacA/B and blaZ probes hybridized to plasmids of similar size in three isolates. Molecular and genetic characterization of the 23-kb plasmid (pST6) of Staphylococcus epidermidis St.6 revealed the presence of qacB adjacent to an incomplete beta-lactamase transposon Tn552 encoding the gene cluster blaZ, blaR, and blaI. Sequence analysis of flanking regions and the intergenic region between blaZ and qacB revealed the presence of IS257 downstream of blaZ as well as sin and binR between blaZ and qacB. In the three other BC and penicillin-resistant strains, the qacA/B and blaZ genes were located on separate plasmids. A qacC harboring S. epidermidis strain (St.17) also hybridized to tetK (tetracycline resistance) and ermB (erythromycin resistance) genes. The individual genes were located on separate plasmids, suggesting no linkage between QAC and antibiotic resistance determinants. Plasmid-free Staphylococcus aureus RN4220 allowed uptake of the pST6 plasmid DNA, indicating that the resistance genes could potentially be transferred to pathogens under selective stress. In conclusion, presence of both resistance determinants could lead to co-selection during antimicrobial therapy or disinfection in hospitals or in food industries.

[Can disinfectants contribute to antibiotic resistance?]

BACKGROUND

Disinfectants are widely used in medicine, veterinary medicine, and the food processing industry. Increasingly, disinfectants are included in consumer products. Broad-scale use of antiseptics and disinfectants may have detrimental ecological consequences, for instance the development of antimicrobial resistance.

MATERIAL AND METHODS

We give an overview of the correlation between the use of certain antiseptics and disinfectants, bacterial resistance to these agents, and antibiotic resistance.

RESULTS

The mechanisms of antibiotic and biocide resistance share many common characteristics. There are links between disinfectant resistance and antibiotic resistance. Some biocides have the ability to select for antibiotic resistant mutants and vice versa. Resistance genes are often located on transferable genetic elements that facilitate horizontal gene transfer between microorganisms. Antibiotic resistance and disinfectant resistance may be stabilized and maintained even in the absence of a direct selective pressure. Higher incidence of bacteria resistant to certain disinfectants have been reported in environments where such agents are frequently used compared to environments where they are not in regular use. Increased domestic usage of non-antibiotic antimicrobial agents may select for antibiotic-resistant bacteria of clinical significance.

INTERPRETATION

The use of antiseptics and disinfectants should be restricted to products and areas where they have an essential and documented effect.

Disinfectant and antibiotic resistance of lactic acid bacteria isolated from the food industry

Quaternary ammonium compounds (QACs) are widely used as disinfectant in medical and food environments. There is a growing concern about the increasing incidence of disinfectant-resistant microorganisms from food. Disinfectant-resistant lactic acid bacteria (LAB) may survive disinfection and cause spoilage problems. Moreover, resistant LAB may potentially act as a reservoir for resistance genes. A total number of 320 LAB from food industry and meat were screened for resistance to the QAC benzalkonium chloride (BC). Out of 320 strains, five strains (1.5%) were considered to be resistant and 56 (17.5%) were tolerant to BC. The resistant strains were isolated from food processing equipment after disinfection. The resistant, tolerant, and some sensitive control bacteria were examined for susceptibility to 18 different antibiotics, disinfectants, and dyes using disc agar diffusion test and microdilution method. Little systematic cross-resistance between BC and any of the antimicrobial agents tested were detected except for gentamycin and chlorhexidine. A BC-tolerant strain was much easier to adapt to higher levels of BC as compared to a BC-sensitive strain. No known gram-positive QAC resistance genes (qacA/B, qacC, qacG, and qacH) were detected in the BC-resistant strains. Identification to species level of the BC-resistant isolates was carried out by comparative analysis of 16S-rDNA sequencing. In conclusion, resistance to BC is not frequent in LAB isolated from food and food environments. Resistance may occur after exposure to BC. The BC resistant isolates showed no cross-resistance with other antimicrobial compounds, except for gentamycin and chlorhexidine. Nevertheless, BC-resistant LAB may be isolated after disinfection and may contribute to the dissemination of resistance.

Comparison of predicted amino acid sequences of measles virus strains in the Edmonston vaccine lineage

Protein-encoding nucleotide sequences of the N, P, M, F, H, and L genes were determined for a low-passage isolate of the Edmonston wild-type (wt) measles virus and five Edmonston-derived vaccine virus strains, including AIK-C, Moraten, Schwarz, Rubeovax, and Zagreb. Comparative analysis demonstrated a high degree of nucleotide sequence homology; vaccine viruses differed at most by 0. 3% from the Edmonston wt strain. Deduced amino acid sequences predicted substitutions in all viral polypetides. Eight amino acid coding changes were common to all vaccine viruses; an additional two were conserved in all vaccine strains except Zagreb. Comparisons made between vaccine strains indicated that commercial vaccine lots of Moraten and Schwarz had identical coding regions and were closely related to Rubeovax, while AIK-C and Zagreb diverged from the Edmonston wt along slightly different paths. These comparisons also revealed amino acid coding substitutions in Moraten and Schwarz that were absent from the closely related reactogenic Rubeovax strain. All of the vaccine viruses contained amino acid coding changes in the core components of the virus-encoded transcription and replication apparatus. This observation, combined with identification of noncoding region nucleotide changes in potential cis-acting sequences of the vaccine strains (C. L. Parks, R. A. Lerch, P. Walpita, H.-P. Wang, M. S. Sidhu, and S. A. Udem, J. Virol. 75:921-933, 2001), suggest that modulation of transcription and replication plays an important role in attenuation.

Analysis of the noncoding regions of measles virus strains in the Edmonston vaccine lineage

The noncoding sequence of five Edmonston vaccine viruses (AIK-C, Moraten, Rubeovax, Schwarz, and Zagreb) and those of a low-passage Edmonston wild-type (wt) measles virus have been determined and compared. Twenty-one nucleotide positions were identified at which Edmonston wt and one or more vaccine strains differed. The location of some of these nucleotide substitutions suggests that they may influence the efficiency of mRNA synthesis, processing, and translation, as well as genome replication and encapsidation. Five nucleotide substitutions were conserved in all of the vaccine strains. Two of these were in the genomic 3'-terminal transcriptional control region and could affect RNA synthesis or encapsidation. Three were found within the 5'-untranslated region of the F mRNA, potentially altering translation control sequences. The remaining vaccine virus base changes were found in one to four vaccine strains. Their genomic localization suggests that some may modify cis-acting regulatory domains, including the Kozak consensus element of the P and M genes, the F gene-end signal, and the F mRNA 5'-untranslated sequence.

Rescue of mumps virus from cDNA

A complete DNA copy of the genome of a Jeryl Lynn strain of mumps virus (15,384 nucleotides) was assembled from cDNA fragments such that an exact antigenome RNA could be generated following transcription by T7 RNA polymerase and cleavage by hepatitis delta virus ribozyme. The plasmid containing the genome sequence, together with support plasmids which express mumps virus NP, P, and L proteins under control of the T7 RNA polymerase promoter, were transfected into A549 cells previously infected with recombinant vaccinia virus (MVA-T7) that expressed T7 RNA polymerase. Rescue of infectious virus from the genome cDNA was demonstrated by amplification of mumps virus from transfected-cell cultures and by subsequent consensus sequencing of reverse transcription-PCR products generated from infected-cell RNA to verify the presence of specific nucleotide tags introduced into the genome cDNA clone. The only coding change (position 8502, A to G) in the cDNA clone relative to the consensus sequence of the Jeryl Lynn plaque isolate from which it was derived, resulting in a lysine-to-arginine substitution at amino acid 22 of the L protein, did not prevent rescue of mumps virus, even though an amino acid alignment for the L proteins of paramyxoviruses indicates that lysine is highly conserved at that position. This system may provide the basis of a safe and effective virus vector for the in vivo expression of immunologically and biologically active proteins, peptides, and RNAs.

Enhanced measles virus cDNA rescue and gene expression after heat shock

Rescue of negative-stranded RNA viruses from full-length genomic cDNA clones is an essential technology for genetic analysis of this class of viruses. Using this technology in our studies of measles virus (MV), we found that the efficiency of the measles virus rescue procedure (F. Radecke et al., EMBO J. 14:5773-5784, 1995) could be improved by modifying the procedure in two ways. First, we found that coculture of transfected 293-3-46 cells with a monolayer of Vero cells increased the number of virus-producing cultures about 20-fold. Second, we determined that heat shock treatment increased the average number of transfected cultures that produced virus another two- to threefold. In addition, heat shock increased the number of plaques produced by positive cultures. The effect of heat shock on rescue led us to test the effect on transient expression from an MV minireplicon. Heat shock increased the level of reporter gene expression when either minireplicon DNA or RNA was used regardless of whether complementation was provided by cotransfection with expression plasmids or infection with MV helper virus. In addition, we found that MV minireplicon gene expression could be stimulated by cotransfection with an Hsp72 expression plasmid, indicating that hsp72 likely plays a role in the effect of heat shock.

A single amino acid change in the hemagglutinin protein of measles virus determines its ability to bind CD46 and reveals another receptor on marmoset B cells

This paper provides evidence for a measles virus receptor other than CD46 on transformed marmoset and human B cells. We first showed that most tissues of marmosets are missing the SCR1 domain of CD46, which is essential for the binding of Edmonston measles virus, a laboratory strain that has been propagated in Vero monkey kidney cells. In spite of this deletion, the common marmoset was shown to be susceptible to infections by wild-type isolates of measles virus, although they did not support Edmonston measles virus production. As one would expect from these results, measles virus could not be propagated in owl monkey or marmoset kidney cell lines, but surprisingly, both a wild-type isolate (Montefiore 89) and the Edmonston laboratory strain of measles virus grew efficiently in B95-8 marmoset B cells. In addition, antibodies directed against CD46 had no effect on wild-type infections of marmoset B cells and only partially inhibited the replication of the Edmonston laboratory strain in the same cells. A direct binding assay with insect cells expressing the hemagglutinin (H) proteins of either the Edmonston or Montefiore 89 measles virus strains was used to probe the receptors on these B cells. Insect cells expressing Edmonston H but not the wild-type H bound to rodent cells with CD46 on their surface. On the other hand, both the Montefiore 89 H and Edmonston H proteins adhered to marmoset and human B cells. Most wild-type H proteins have asparagine residues at position 481 and can be converted to a CD46-binding phenotype by replacement of the residue with tyrosine. Similarly, the Edmonston H protein did not bind CD46 when its Tyr481 was converted to asparagine. However, this mutation did not affect the ability of Edmonston H to bind marmoset and human B cells. The preceding results provide evidence, through the use of a direct binding assay, that a second receptor for measles virus is present on primate B cells.

Respiratory syncytial virus (RSV) SH and G proteins are not essential for viral replication in vitro: clinical evaluation and molecular characterization of a cold-passaged, attenuated RSV subgroup B mutant

A live, cold-passaged (cp) candidate vaccine virus, designated respiratory syncytial virus (RSV) B1 cp-52/2B5 (cp-52), replicated efficiently in Vero cells, but was found to be overattenuated for RSV-seronegative infants and children. Sequence analysis of reverse-transcription-PCR-amplified fragments of this mutant revealed a large deletion spanning most of the coding sequences for the small hydrophobic (SH) and attachment (G) proteins. Northern blot analysis of cp-52 detected multiple unique read-through mRNAs containing SH and G sequences, consistent with a deletion mutation spanning the SH:G gene junction. Immunological studies confirmed that an intact G glycoprotein was not produced by the cp-52 virus. Nonetheless, cp-52 was infectious and replicated to high titer in tissue culture despite the absence of the viral surface SH and G glycoproteins. Thus, our characterization of this negative-strand RNA virus identified a novel replication-competent deletion mutant lacking two of its three surface glycoproteins. The requirement of SH and G for efficient replication in vivo suggests that selective deletion of one or both of these RSV genes may provide an alternative or additive strategy for developing an optimally attenuated vaccine candidate.

Rescue of synthetic measles virus minireplicons: measles genomic termini direct efficient expression and propagation of a reporter gene

Measles virus (MV) mRNA transcription and replication are thought to be controlled by cis-acting sequence elements contained within the terminal MV genomic noncoding nucleotides. To validate these promoter and regulatory signal assignments, cDNAs were constructed allowing synthesis of RNAs corresponding to a MV genome in which all coding and intercistronic regions were replaced by the chloramphenicol acetyl transferase (CAT) coding sequence. Transcript production by T7 polymerase starting and ending precisely with the MV genome terminal residues was achieved by fusing the T7 polymerase promoter and the hepatitis delta virus genome ribozyme followed by tandem T7 polymerase termination sequences to the MV genomic 5' and 3' ends, respectively. Transfection of these negative polarity transcripts, mimicking natural defective interfering RNAs of the internal deletion type, into MV-infected 293 cells gave rise to CAT activity which could be serially transferred and massively amplified together with progeny helper virus in fresh cells. Transfer was blocked only by antibodies able to neutralize MV infectivity, indicating that the chimeric RNA not only was encapsidated, transcribed, and replicated, but also packaged into virions. Sequence analyses confirmed that both the expected chimeric antigenome and mRNA products were transcribed and replicated with fidelity during serial passage. Minor changes introduced in the transcription promoter markedly compromised function. This system now can be exploited to examine MV genomic cis-acting regulatory elements and extended to the development of full-length MV cDNAs.

Cephalometric analysis of changes produced by a modified Herbst appliance in the treatment of Class II division 1 malocclusion

This study investigated treatment changes produced by the Herbst appliance in a sample of severe Class II division 1 cases, over a period of 8 months. The sample consisted of 16 girls, of whom eight were treated by the Herbst appliance, whilst eight served as controls. All cases were matched with respect to age, sex, skeletofacial morphology, and length of treatment/observation period. Twenty-two skeletal and 19 dental parameters were recorded on pre- and post-treatment cephalograms. The net treatment effect of Herbst therapy was evaluated, taking into account the growth that occurred in the control sample. The study revealed that during 8 months of Herbst therapy there was a significant increase in mandibular length, along with sagittal repositioning. The skeletal changes in the mandible were mainly responsible for overjet and molar relation correction. A slight, favourable forward rotation of the mandible was identified. Dentoalveolar features included flaring of lower incisors and distalization of upper molars. The appliance did not have any retrusive effect on the maxilla. The modified splint design differed from the original and was cemented rather than bonded.

Central giant cell granuloma of jaws--review of 19 cases

19 cases of central giant cell granuloma (CGCG) were reviewed after screening the records of the past four years of the Dental out patient department of AIIMS Hospital, New Delhi. It was found that CGCG usually occurs in the 2nd and 3rd decades and is more common in females. The mandible is more frequently involved than the maxilla and lesions occur more commonly on the right than left side.

Defective measles virus in human subacute sclerosing panencephalitis brain

Evidence is presented showing that the brain cells of patients with subacute sclerosing panencephalitis (SSPE) contain mutant measles (MV) genomes having the characteristics of 5' copy-back defective interfering (DI) RNAs. Using a polymerase chain reaction-based amplification specific for copy-back DIs, abundant, discrete cDNAs representing different-sized MV defective RNA species were generated from each SSPE brain. The defective genomes were cloned in two portions. The most common of these defective species were sequenced, confirming their MV genome origin and 5' copy-back nature. We deduced that the minimum DI stem length of these species was 95 nucleotides, further delimiting the prerequisite 5' regulatory region sequences specifying MV genomic replication/encapsidation functions. This calculation assumes a precise copy-back mechanism and complete complementarity of the panhandle structure. Since the SSPE-derived viral genome encodes dysfunctional viral envelope proteins, we hypothesize that SSPE brains may lack the high degree of selective pressure encountered in tissue culture MV infections. This allows for the coexistence of numerous replication-competent defective particles in each SSPE brain. A role for viral defective particles as modulators of this persistent measles virus infection of humans is proposed.

Canine distemper virus L gene: sequence and comparison with related viruses

We cloned the genomic RNA of canine distemper virus (CDV) and determined the nucleotide sequence of the large (L) protein-coding gene. The L gene is 6573 nucleotides long and contains a single open reading frame coding for a polypeptide of 2161 amino acids (MW 246,354). The precise 5' end of the viral genome consists of a 38-nucleotide leader region. The CDV L protein shows over 77% amino acid similarity with its morbilliform relative measles virus (MV) with nearly 67% of their amino acids conserved. The sequence homology of 11 negative strand viruses L proteins is compared and relatedness was found in the following decreasing order: CDV, MV, Sendai virus, parainfluenza virus type 3, simian virus 5, parainfluenza virus type 2, mumps virus, Newcastle disease virus, respiratory syncytial virus, vesicular stomatitis virus, rabies virus. The consensus sequence of proposed functional domains involved in L gene catalytic activities was well conserved in the CDV L protein.

Canine distemper terminal and intergenic non-protein coding nucleotide sequences: completion of the entire CDV genome sequence

Sequences critical for the transcription and replication functions of canine distemper virus (CDV) RNA polymerase were analyzed. The sequence was obtained from polymerase chain reaction (PCR) products using either c-DNA clones from a genomic library as template or in most instances genomic CDV RNA. Clones coding for the precise 3'- and 5'-ends of the CDV genome were sequenced and the results confirmed by additional PCR experiments. The virtual identity of terminal sequences and spacing at the two noncoding ends speak to the importance of these areas in replication and transcription. The sequence for each of the CDV gene boundaries was defined and all were compared to related viruses. This report completes the sequence determination of the CDV genome.

Fingerprinting human chromosomes by polymerase chain reaction-mediated DNA amplification

We describe here a method for DNA fingerprinting of human chromosomes by Alu-polymerase chain reaction (PCR) amplification of DNA from monochromosomal hybrids, following digestion with restriction endonucleases. DNA digestion with restriction enzymes prior to PCR amplification reduces the total number of amplified fragments. The number and pattern of bands of PCR products observed in an electrophoretic medium are chromosome specific and provide a "fingerprint signature" for individual human chromosomes. Using this approach, we have produced fingerprints for human chromosomes 2, 5, 7, 9, and 12. The applicability of this approach to chromosome identification was assessed by comparing the fingerprints obtained for two different hybrids containing chromosome 7. DNA fragments specific for the long and the short arms of human chromosome 12 have also been identified. In addition, Alu-PCR-generated DNA fragments, specific for different chromosomes, were used to probe Southern blots of a hybrid cell panel to identify human chromosomes present in hybrid cell lines. The chromosomal specificity of these probes permits the identification of intact as well as rearranged chromosomes composed of segments arising from more than one chromosome.

Production, localization and glucose repression of beta-glucosidase in Trichoderma longibrachiatum

Optimal production of beta-glucosidase was obtained by incubating the culture at 27 degrees C in a growth medium that had an initial pH of 5.0 and contained cellobiose. The bulk of the enzyme (70%) was present in a cell-associated state (cell debris and cytosol) while only a small portion (30%) appeared in the culture filtrate. When cellulosic substrates were used, the major portion of the enzyme (70%) appeared in the extracellular fraction. A repression of the enzyme occurred in the presence of glucose. A drop of the pH of the medium during the exponential growth phase coincided with a rapid inactivation of the enzyme. The glucose effect was most likely mediated by adverse effects of low pH on the integrity of the enzyme.

Effects of prostaglandin E2 analogue suppository on blood loss in suction abortion

The purpose of the present clinical investigation was to determine the effect of preoperative treatment with a long-acting prostaglandin suppository containing 9-deoxo-16,16-dimethyl-9-methylene prostaglandin E2 on uterine blood loss in patients undergoing preoperative cervical dilatation before transcervical abortion. Ninety-five young women in the ninth to 14th week of gestation were randomly assigned to one of two groups. Patients in group 1 were treated with a long-acting prostaglandin suppository and group 2 patients acted as control subjects. At the end of three hours, patients in both groups underwent abortion with careful intraoperative measurement of blood loss in both groups. The blood loss in the prostaglandin-treated group was significantly lower than that in the control group (69.0 +/- 14.1 mL versus 151.1 +/- 26.6 mL). The difference in intraoperative blood loss was observed at all gestations between nine and 14 weeks. There was significantly greater dilation of the cervix after prostaglandin treatment (mean difference, 4.58 mm; P less than .005).

An unusual complication of extradural catheterization in obstetric anaesthesia

An extradural catheter was inserted at the third lumbar interspace for relief of pain during labour in a 21-year-old gravid patient. Attempts to withdraw the catheter met with resistance and produced severe pain in the distribution of the second left lumbar nerve. Radiography revealed an acutely angled loop of the catheter over the L2-3 nerve root.