Effect of nutrients deficiency on biofilm formation and single cell protein production with a purple non-sulphur bacteria enriched culture

Purple non-sulphur bacteria (PNSB) are of interest for biorefinery applications to create biomolecules, but their production cost is expensive due to substrate and biomass separation costs. This research has utilized fuel synthesis wastewater (FSW) as a low-cost carbon-rich substrate to produce single-cell protein (SCP) and examines PNSB biofilm formation using this substrate to achieve a more efficient biomass-liquid separation. In this study, PNSB were grown in Ca, Mg, S, P, and N-deficient media using green shade as biofilm support material. Among these nutrient conditions, only N-deficient and control (nutrient-sufficient) conditions showed biofilm formation. Although total biomass growth of the control was 1.5 times that of the N-deficient condition and highest overall, the total biofilm-biomass in the N-deficient condition was 2.5 times greater than the control, comprising 49% of total biomass produced. Total protein content was similar between these four biomass samples, ranging from 35.0 ± 0.2% to 37.2 ± 0.0%. The highest protein content of 44.7 ± 1.3% occurred in the Mg-deficient condition (suspended biomass only) but suffered from a low growth rate. Overall, nutrient sufficient conditions are optimal for overall protein productivity and dominated by suspended growth, but where fixed growth systems are desired for cost-effective harvesting, N-deficient conditions provide an effective means to maximize biofilm production without sacrificing protein content.

Protective and Curative Effects of Ethanol extract of Tinospora Cordifolia on Gentamicin-induced Nephrotoxicity in Rats

Gentamicin induced acute tubular necrosis (ATN) in intrinsic variety of acute renal failure (ARF) results from oxidative stress leading to cellular lipid peroxidation. Tinospora cordifolia (Tc), locally named as 'Guluncha' is an herbal plant with medicinal value possess antioxidant property as well as significant scavenging activity in different extracts and easily available in Bangladesh. This prospective study was approved by the Institutional Review Board of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. This study was conducted to assess the effect of ethanol extract of Tc on gentamicin induced renal damage in rats in the department of Pharmacology, BSMMU, Dhaka, Bangladesh from January 2014 to June 2014. For this purpose, sixty rats were divided into six equal groups. Gentamicin (80mg/kg/day, 7 days) was administered and nephrotoxicity was evaluated biochemically by estimating elevated levels of serum creatinine and serum urea. Extant of lipid peroxidation was assessed by estimating renal cortical malondialdehyde (MDA) levels. The ethanol extract of Tc (200mg/kg/day) was administered with gentamicin concurrently and also consecutively to detect preventive and curative effects respectively. Statistically significant amelioration in the biochemical parameters both in serum and renal tissue suggested that active compound or compounds extracted from Tinospora cordifolia have both protective and curative effects against nephrotoxicity, though responsible active ingredient, accurate mechanism or safety profile was not confirmed by this study.

Correlation between HRCT Findings of Symptomatic COVID-19 Patient with RT-PCR Test in a Tertiary Hospital of Bangladesh

The COVID-19 pandemic has turned into a global calamity and affected millions of lives around the world. Even though the vaccination efforts have started, they are yet to have an effective impact on the lower to middle-income countries. Early detection and isolation are still the best way to control the spread of the virus. The standard practice for detecting COVID-19 is the RT-PCR (Reverse Transcription Polymerase Chain Reaction) test but this test has a high probability of producing false-negative results plus lack of availability at all the time due to shortage of kit. Since COVID-19 is a respiratory disease affecting the lungs and the imaging patterns caused by COVID-19 can be observed in chest HRCT (High Resolution Computed Tomography) scans. As a result, HRCT can be used as an alternative diagnostic modality for any suspected cases of COVID-19. In this cross-sectional study was carried out in the Department of Radiology and Imaging, BSMMU, Dhaka, Bangladesh from May 12, 2020 to August 10, 2020. Chest HRCT scans of 284 suspected patients irrespective of age and sex who had done RT-PCR test either positive or negative test result having symptoms suggesting COVID pneumonia were enrolled in this study. Patients who had not done RT-PCR and who were not willing to do HRCT chest were excluded. According to the study, ground glass opacity is the most common feature and found in 89.44% of patients. The other predominant features were including consolidation, crazy paving, fibrotic density and vascular enlargement. The diagnostic performance of the CT scan was also evaluated using the RT-PCR test result as the gold standard and the sensitivity, specificity, and accuracy of the CT scan diagnosis were found to be 83.2%, 50% and 79.9% respectively. The severity of the five lung lobes has also been studied. The right middle lobe and the left upper lobe seemed to be in more severe condition for most of the patients compared to the other lung lobes.

Comparative Efficacy, Safety, Tolerability, and Effectiveness of Antipsychotics in The Treatment of Dementia-Related Psychosis (DRP): A Systematic Literature Review

OBJECTIVES

To evaluate the comparative efficacy, safety, tolerability, and effectiveness of atypical antipsychotics (AAPs) for the treatment of dementia related psychosis (DRP) in older adults.

METHODS

In this systematic literature review (SLR), we qualitatively synthesized evidence on the comparative efficacy (based on neuropsychiatric inventory), tolerability (weight gain), and safety (cerebrovascular adverse events [CVAE], cardiovascular events, mortality, somnolence, extrapyramidal symptoms [EPS]) of AAPs used to treat DRP. We also assessed effectiveness based on all-cause discontinuations and discontinuations due to lack of efficacy or adverse events (AE). Published articles from through March 2021 from PubMed, EMBASE, PsycINFO, and Cochrane databases evaluated. We included double-blind, active-comparator/placebo-controlled randomized trials, open-label trials, and observational studies.

RESULTS

This qualitative synthesis included 51 eligible studies with sample size of 13,334 and mean age of 79.36 years. Risperidone, olanzapine, quetiapine, and aripiprazole demonstrated numerically small improvement in psychotic symptoms among patients with DRP. Somnolence was the most reported AE for all the AAPs, with weight gain and tardive dyskinesia more common with olanzapine and risperidone, respectively. These AAPs are associated with falls, EPS, cognitive declines, CVAE, and mortality. Aripiprazole and olanzapine had lower odds of discontinuation due to lack of efficacy, with olanzapine having greater discontinuation odds due to AEs.

CONCLUSION

This SLR demonstrated that AAPs used off-label to treat DRP are associated with small numerical symptom improvement but with a high risk of AEs, including cognitive decline and potentially higher mortality. These results underscore the need for new treatments with a favorable benefit-risk profile for treating DRP.

Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan

Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.

Morphological Effect of Ethanol Extract of Tinospora cordifolia on Gentamicin-induced Nephrotoxicity in Rats

Recent studies indicate that cellular lipid peroxidation by free radical is an underlying mechanism of acute renal failure induced by gentamicin (GM). Tinospora cordifolia (Tc) extract has been reported to have antioxidant and free radical scavenging activities that is why it is used in present study with the expectation to interrupt the toxic free radical chain reaction of lipid peroxidation in the course of gentamicin administration. For this purpose, sixty rats were divided into six equal groups. Gentamicin (80mg/kg/day, 7 days) was administered to produce nephrotoxicity and structural alterations were evidenced from histopathology of renal tissues which indicates the renal injury and dysfunction in rats. The ethanol extract of Tinospora (200mg/kg/day) was administered with gentamicin simultaneously and also sequentially to observe preventive and curative effects respectively. Both the groups recovered from the gentamicin-induced nephrotoxicity, evidenced from improvement of histopathological features, though accurate mechanism and safety profile is not confirmed by this study.

Raman spectroscopy of blood plasma samples from breast cancer patients at different stages

Raman spectroscopy was employed for the characterization of blood plasma samples from patients at different stages of breast cancer. Blood plasma samples taken from clinically diagnosed breast cancer patients were compared with healthy controls using multivariate data analysis techniques (principal components analysis - PCA) to establish Raman spectral features which can be considered spectral markers of breast cancer development. All the stages of the disease can be differentiated from normal samples. It is also found that stage 2 and 3 are biochemically similar, but can be differentiated from each other by PCA. The Raman spectral data of the stage 4 is found to be biochemically distinct, but very variable between patients. Raman spectral features associated with DNA and proteins were identified, which are exclusive to patient plasma samples. Moreover, there are several other spectral features which are strikingly different in the blood plasma samples of different stages of breast cancer. In order to further explore the potential of Raman spectroscopy as the basis of a minimally invasive screening technique for breast cancer diagnosis and staging, PCA-Factorial Discriminant Analysis (FDA) was employed to classify the Raman spectral datasets of the blood plasma samples of the breast cancer patients, according to different stages of the disease, yielding promisingly high values of sensitivity and specificity for all stages.

Principal components analysis of Raman spectral data for screening of Hepatitis C infection

In the current study, Raman spectroscopy is employed for the identification of the biochemical changes taking place during the development of Hepatitis C. The Raman spectral data acquired from the human blood plasma samples of infected and healthy individuals is analysed by Principal Components Analysis and the Raman spectral markers of the Hepatitis C Virus (HCV) infection are identified. Spectral changes include those associated with nucleic acidsat720 cm^-1, 1077 cm^-1 1678 (CO stretching mode of dGTP of RNA), 1778 cm^-1 (RNA), with proteins at 1641 cm^-1(amide-I), 1721 cm^-1(CC stretching of proteins) and lipids at 1738 cm^-1(CO of ester group in lipids). These differences in Raman spectral features of blood plasma samples of the patients and healthy volunteers can be associated with the development of the biochemical changes during HCV infection.

Raman spectral analysis for rapid screening of dengue infection

Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated with lipidic and amino acid/protein content are observed and assigned based on literature and these features can be considered as markers associated with dengue development. Based on the spectroscopic analysis of the current, albeit limited, cohort of samples, Principal Components Analysis (PCA) coupled Factorial Discriminant Analysis, yielded values of 97.95% sensitivity and 95.40% specificity for identification of dengue infection. Furthermore, in a comparison of the normal samples to the patient samples which scored low for only one of the biomarker tests, but high or medium for either or both of the other two, PCA-FDA demonstrated a sensitivity of 97.38% and specificity of 86.18%, thus providing an unambiguous screening technology.

Structural studies of substrate and product complexes of 5-aminolaevulinic acid dehydratase from humans,Escherichia coliand the hyperthermophilePyrobaculum calidifontis

A number of X-ray analyses of an enzyme involved in a key early stage of tetrapyrrole biosynthesis are reported. Two structures of human 5-aminolaevulinate dehydratase (ALAD), native and recombinant, have been determined at 2.8 Å resolution, showing that the enzyme adopts an octameric quaternary structure in accord with previously published analyses of the enzyme from a range of other species. However, this is in contrast to the finding that a disease-related F12L mutant of the human enzyme uniquely forms hexamers [Breiniget al.(2003),Nature Struct. Biol.10, 757–763]. Monomers of all ALADs adopt the TIM-barrel fold; the subunit conformation that assembles into the octamer includes the N-terminal tail of one monomer curled around the (α/β)8barrel of a neighbouring monomer. Both crystal forms of the human enzyme possess two monomers per asymmetric unit, termedAandB. In the native enzyme there are a number of distinct structural differences between theAandBmonomers, with the latter exhibiting greater disorder in a number of loop regions and in the active site. In contrast, the second monomer of the recombinant enzyme appears to be better defined and the active site of both monomers clearly possesses a zinc ion which is bound by three conserved cysteine residues. In native human ALAD, theAmonomer also has a ligand resembling the substrate ALA which is covalently bound by a Schiff base to one of the active-site lysines (Lys252) and is held in place by an ordered active-site loop. In contrast, these features of the active-site structure are disordered or absent in theBsubunit of the native human enzyme. The octameric structure of the zinc-dependent ALAD from the hyperthermophilePyrobaculum calidifontisis also reported at a somewhat lower resolution of 3.5 Å. Finally, the details are presented of a high-resolution structure of theEscherichia coliALAD enzyme co-crystallized with a noncovalently bound moiety of the product, porphobilinogen (PBG). This structure reveals that the pyrrole side-chain amino group is datively bound to the active-site zinc ion and that the PBG carboxylates interact with the enzymeviahydrogen bonds and salt bridges with invariant residues. A number of hydrogen-bond interactions that were previously observed in the structure of yeast ALAD with a cyclic intermediate resembling the product PBG appear to be weaker in the new structure, suggesting that these interactions are only optimal in the transition state.

Placenta accreta and anesthesia: A multidisciplinary approach

Placenta accreta (an abnormally adherent placenta) is one of the two leading causes of peripartum hemorrhage and the most common indication for peripartum hysterectomy. Placenta accreta may be associated with significant maternal hemorrhage at delivery owing to the incomplete placental separation. When placenta accreta is diagnosed before delivery, a multidisciplinary approach may improve patient outcome.

Targeting IL-17A in multiple myeloma: a potential novel therapeutic approach in myeloma

We have previously demonstrated that interleukin-17A (IL-17) producing Th17 cells are significantly elevated in blood and bone marrow (BM) in multiple myeloma (MM) and IL-17A promotes MM cell growth via the expression of IL-17 receptor. In this study, we evaluated anti-human IL-17A human monoclonal antibody (mAb), AIN457 in MM. We observe significant inhibition of MM cell growth by AIN457 both in the presence and absence of BM stromal cells (BMSC). While IL-17A induces IL-6 production, AIN457 significantly down-regulated IL-6 production and MM cell-adhesion in MM-BMSC co-culture. AIN-457 also significantly inhibited osteoclast cell–differentiation. More importantly, in the SCIDhu model of human myeloma administration of AIN-457 weekly for 4 weeks after the first detection of tumor in mice led to a significant inhibition of tumor growth and reduced bone damage compared to isotype control mice. To understand the mechanism of action of anti-IL-17A mAb, we report here, that MM cells express IL-17A. We also observed that IL-17A knock-down inhibited MM cell growth and their ability to induce IL-6 production in co-cultures with BMSC. These pre-clinical observations suggest efficacy of AIN 457 in myeloma and provide the rationale for its clinical evaluation for anti-myeloma effects and for improvement of bone disease.

Escherichia coli signal peptidase recognizes and cleaves the signal sequence of α-amylase originating from Bacillus licheniformis

The gene encoding the α-amylase from Bacillus licheniformis was cloned, with and without the native signal sequence, and expressed in Escherichia coli, resulting in the production of the recombinant protein in the cytoplasm as insoluble but enzymatically active aggregates. Expression with a low concentration of the inducer at low temperature resulted in the production of the recombinant protein in soluble form in a significantly higher amount. The protein produced with signal sequence was exported to the extracellular medium, whereas there was no export of the protein produced from the gene without the signal sequence. Similarly, the α-amylase activity in the culture medium increased with time after induction in case of the protein produced with signal sequence. Molecular mass determinations by MALDI-TOF mass spectrometry and N-terminal amino acid sequencing of the purified recombinant α-amylase from the extracellular medium revealed that the native signal peptide was cleaved by E. coli signal peptidase between Ala28 and Ala29. It seems possible that the signal peptide of α-amylase from B. licheniformis can be used for the secretion of other recombinant proteins produced using the E. coli expression system.

Post transfusion lung injury in the neonatal population

OBJECTIVE

The objective of this study was to examine the changes in level of respiratory support following transfusion in neonates who require intermediate or intensive care.

STUDY DESIGN

Data on respiratory support were collected retrospectively from the medical record before, during and after transfusion. Neonatal post transfusion lung injury (NPTLI) was defined as an increase in the highest mean airway pressure (MAP) of ≥2 cm H(2)O or FiO(2) >0.15 in the 6-h after transfusion that persisted from 6 to 18 h post transfusion.

RESULT

A total of 373 (330 packed red blood cell) transfusions were given to 108 infants. NPTLI occurred following 31 (8.3%) transfusions in 23 patients. During the first 6 h after transfusion, FiO2 or MAP was increased in 47 transfusions (12.6%) and the changes persisted in 31 transfusions (7.8%). Infants who developed NPTLI were less mature (27.1±0.7 vs 31.0±0.5 weeks; P=0.005) and of lower birth weight (1001±110 vs1692±104 g; P=0.001). Infants who developed NPTLI were more likely to develop necrotizing enterocolitis (6/24 vs 4/85; P=0.002) and die within 24 h of transfusion (5/22 vs 3/85; P=0.003).

CONCLUSION

In neonates receiving intensive or intermediate care, blood transfusion was associated with need for increased respiratory support in a significant number of cases. Development of NPTLI was associated with poorer outcomes.

Role of routine oesophago-gastroduodenoscopy before cholecystectomy

INTRODUCTION

A proportion of patients do not get symptomatic relief after cholecystectomy because there is an overlap in the symptomology of biliary and gasroduodenal pathologies. In our unit all the patients are offered gastroscopy prior to Cholecystectomy. Aim of this study was to evaluate the efficacy of gastroscopy in all patients with upper abdominal pain irrespective of ultrasound findings.

MATERIAL AND METHODS

This retrospective study was carried out, between Jan 2001-Oct 2003. All the patients undergoing laparoscopic cholecystectomy by a single surgeon were studied. Group 1 (n = 61) were not endoscoped before the operation (Jan 2001-May 2002). Group 2 (n = 60) had routine endoscopy carried out before surgery (June 2002-October 2003). The results were entered in a database and analyzed.

RESULTS

Total of 240 laparoscopic cholecystectomies were carried out. Female to male ratio was 4:1. In Group 1, the recurrence or persistence of symptoms was 20/61 (32.78%) patients who were not scoped. In Group 2, all patients were scoped with positive findings in 35% of the patients. All were treated for the pathology and only 2(3.3%) had recurrence or persistence of symptoms.

CONCLUSION

The routine use of gastroscopy before laparoscopic cholecystectomy helps to reduce persistence of symptoms and is recommended.

An analysis of renal dysfunction in 1511 patients with fractured neck of femur: the implications for peri-operative analgesia

SUMMARY

Following two deaths from respiratory failure secondary to opioid toxicity in patients admitted for surgical repair of fractured neck of femur, we retrospectively studied the serum urea and electrolyte concentrations of 1511 consecutive patients requiring surgery for proximal femoral fracture, and calculated their glomerular filtration rate. Five hundred and forty-five (36.1%) patients had renal dysfunction on admission (glomerular filtration rate < 60 ml x min(-1).1.73 m(-2)); 435 (28.8%) had grade 3 chronic kidney disease (moderate; glomerular filtration rate 30-59 ml x min(-1).1.73 m(-2)), 82 (5.4%) had grade 4 disease (severe; glomerular filtration rate 15-29 ml x min(-1).1.73 m(-2)) and 28 (1.9%) had grade 5 (renal failure; glomerular filtration rate < 15 ml min(-1).1.73 m(-2)). The 30-day mortality for patients with renal dysfunction (62/536; 11.6%) was significantly greater (p = 0.004) than for patients with normal renal function (68/958; 7.1%), although median (IQR [range]) postoperative lengths of stay were similar 15 (10-22 [1-125]) vs 14 (9-22 [1-120]) days respectively; p = 0.06). Renal impairment is common in patients admitted for fixation of fractured neck of femur, who are consequently at risk of opioid toxicity.

Crystallization and preliminary X-ray diffraction analysis of L-threonine dehydrogenase (TDH) from the hyperthermophilic archaeon Thermococcus kodakaraensis

The enzyme L-threonine dehydrogenase catalyses the NAD(+)-dependent conversion of L-threonine to 2-amino-3-ketobutyrate, which is the first reaction of a two-step biochemical pathway involved in the metabolism of threonine to glycine. Here, the crystallization and preliminary crystallographic analysis of L-threonine dehydrogenase (Tk-TDH) from the hyperthermophilic organism Thermococcus kodakaraensis KOD1 is reported. This threonine dehydrogenase consists of 350 amino acids, with a molecular weight of 38 kDa, and was prepared using an Escherichia coli expression system. The purified native protein was crystallized using the hanging-drop vapour-diffusion method and crystals grew in the tetragonal space group P4(3)2(1)2, with unit-cell parameters a = b = 124.5, c = 271.1 A. Diffraction data were collected to 2.6 A resolution and preliminary analysis indicates that there are four molecules in the asymmetric unit of the crystal.

Surface charge and the effect of excess calcium ions on the hydroxyapatite surface

This paper describes the use of surface titration as a more direct probe of the surface chemistry of hydroxyapatite (HA) than zeta-potential measurements. The variation in HA surface charge with pH for two different KCl electrolyte concentrations was determined titrimetrically and the point of zero charge (PZC) found to be at a pH of 7.3 +/- 0.1. The curves also demonstrated that HA accumulates positive charge more readily below the PZC than it accumulates negative charge above it. Extended titration data indicated that dissolution occurred more rapidly in increasingly acidic conditions, but was inhibited by increasing electrolyte strength. Similar experiments with 2.5 mM Ca(2+) in the electrolyte show that Ca(2+) adsorption balances loss of H(+) to give a near-neutral surface at any pH above 7 (subject to availability of calcium ions and adsorption sites). The mechanism for adsorption has been shown to be deprotonation of adjacent surface HPO(4)(2-) sites and subsequent adsorption of a calcium ion to the lattice surface site. Furthermore, inhibition of dissolution under alkaline conditions in the presence of Ca(2+) suggested that dissolution was driven by desorption of Ca(2+). Modelling of the adsorption/desorption processes demonstrated that in both pure water and under physiological conditions phosphate groups will predominate at the HA surface. Furthermore, the (200) plane was identified as the likely form of the HA surface. These methodologies and findings are particularly relevant to investigation of biological response with respect to modification of surface hydrophobicity and surface energy or charge.

Isolation and characterization of psychrotrophs from subterranean environments

Subterranean environments are potential sources for the isolation of novel microorganisms. Water and soil samples were collected at depths ranging from 10 to 1800 meters below the surface, and screening was carried out with aerobic rich and anaerobic minimal media. Two psychrotrophic and three chemoautotrophic strains were isolated. One of the psychrotrophic isolates, designated SN16A, grew at temperatures between -5 and 37 degrees C with optimal growth between 25 and 30 degrees C. The other psychrotroph, designated KB700A, grew between -10 and 30 degrees C. Little difference in growth rate could be observed between 20 and 30 degrees C; however, this strain did not grow at 37 degrees C. KB700A utilized CO2 chemoautotrophically at 30 degrees C, using hydrogen as an energy source. Both strains were characterized biochemically. The complete 16S rRNA sequence of KB700A was 98.7% homologous with that of Pseudomonas marginalis. However, the 16S rRNA of SN16A showed only 95.4% identity at maximum-with the corresponding gene of Arthrobacter globiformis-suggesting that this strain may belong to a novel genus. Both strains exhibited the ability to produce hydrolytic enzymes on plate assays. Our results suggest that subterranean environments are promising sources for the isolation of psychrotrophic microorganisms.

Successful treatment of a patient with mixed warm and cold antibody mediated Evans syndrome and glucose intolerance

Thrombocytopenia and autoimmune hemolytic anemia (Evans syndrome) with the presence of both warm and cold autoantibodies (mixed type) are rare in the pediatric age group. This condition may be associated with other autoimmune disorders and is notoriously difficult to treat. This case describes an adolescent male who presented with rapid onset Evans syndrome and diabetes. After failing to respond to high dose prednisone and intravenous immunoglobulin, the patient was successfully treated with monoclonal antibody against CD20 (anti-CD20). This suggests that anti-CD20 is a valuable treatment for severe warm and cold antibody mediated Evans syndrome, and possibly for select cases of antibody mediated diabetes.

Closure of aortopulmonary window with amplatzer duct occluder device

Aortopulmonary window is a relatively uncommon congenital heart defect. We report on a patient with a small aortopulmonary window, who presented with an asymptomatic murmur and in whom catheter closure was successfully performed with an Amplatzer Duct Occluder.

Low-temperature lipase from psychrotrophic Pseudomonas sp. strain KB700A

We have previously reported that a psychrotrophic bacterium, Pseudomonas sp. strain KB700A, which displays sigmoidal growth even at -5 degrees C, produced a lipase. A genomic DNA library of strain KB700A was introduced into Escherichia coli TG1, and screening on tributyrin-containing agar plates led to the isolation of the lipase gene. Sequence analysis revealed an open reading frame (KB-lip) consisting of 1,422 nucleotides that encoded a protein (KB-Lip) of 474 amino acids with a molecular mass of 49,924 Da. KB-Lip showed 90% identity with the lipase from Pseudomonas fluorescens and was found to be a member of Subfamily I.3 lipase. Gene expression and purification of the recombinant protein were performed. KB-Lip displayed high lipase activity in the presence of Ca2+. Addition of EDTA completely abolished lipase activity, indicating that KB-Lip was a Ca2+-dependent lipase. Addition of Mn2+ and Sr2+ also led to enhancement of lipase activity but to a much lower extent than that produced by Ca2+. The optimal pH of KB-Lip was 8 to 8.5. The addition of detergents enhanced the enzyme activity. When p-nitrophenyl esters and triglyceride substrates of various chain-lengths were examined, the lipase displayed highest activity towards C10 acyl groups. We also determined the positional specificity and found that the activity was 20-fold higher toward the 1(3) position than toward the 2 position. The optimal temperature for KB-Lip was 35 degrees C, lower than that for any previously reported Subfamily I.3 lipase. The enzyme was also thermolabile compared to these lipases. Furthermore, KB-Lip displayed higher levels of activity at low temperatures than did other enzymes from Subfamily I.3, indicating that KB-Lip has evolved to function in cold environments, in accordance with the temperature range for growth of its psychrotrophic host, strain KB700A.

A new suture for hair transplantation: poliglecaprone 25

BACKGROUND

The most common type of donor closure in hair transplantation is with nonabsorbable, running sutures, usually of nylon or polypropylene. This is accomplished with or without buried absorbable sutures. Another popular method of closure is with stainless steel staples. Each of these methods has benefits and limitations with respect to healing, comfort, and convenience for the patient.

OBJECTIVE

The purpose of this study is to describe the use of poliglecaprone 25, a synthetic, absorbable, monofilament suture in hair transplantation surgery, to detail the suturing techniques needed to maximize the benefit of this suture, and to compare this material and suturing technique to a well-established form of closure, that of metal staples in a bilaterally controlled fashion.

METHODS

Poliglecaprone 25 is a synthetic, absorbable monofilament suture of low tissue reactivity. It was compared to closure with metal staples in a bilateral controlled study. One side of the donor area was closed with poliglecaprone 25 sutures using a running cutaneous stitch and the other side was closed with stainless steel staples. Patients were evaluated with regard to healing, postoperative discomfort, resultant surgical scar, and closure material preference.

RESULTS

Of the 22 patients studied, the following postoperative complaints were noted on the staples side: tenderness (12), itching (4), swelling (2), and scabbing (1). This compared to only one complaint of itching and one complaint of swelling on the poliglecaprone 25 side. Two patients had postoperative complaints of visibility of staples showing through their hair. Objective measurements revealed a wider scar overall on the staples side in six patients and wider scar on the suture side in two patients. The average scar width on the staples side measured 1.78 mm compared to 1.42 mm on the suture side. Fourteen of the 22 patients preferred poliglecaprone 25 for future procedures, 1 preferred metal staples, and 7 had no preference. Most patients stated that postoperative discomfort from the staples and the inconvenience and occasional pain associated with their removal was responsible for their decision.

CONCLUSION

Poliglecaprone 25 is a strong synthetic, absorbable, monofilament suture with low tissue reactivity that can be used in hair transplantation to close the donor wound with a single, running cutaneous stitch. This suture can provide a donor closure that ensures hemostasis, has little risk of infection, and is comfortable for the patient. If specific surgical techniques are followed, this suture can provide a donor closure that ensures hemostasis has little risk of complications, is both comfortable and convenient for the patient postoperatively and results in a fine surgical scar.

Crystallization and preliminary X-ray study of Pk--REC from a hyperthermophilic archaeon, Pyrococcus kodakaraensis KOD1

Pk-REC is a protein which binds to DNA and catalyzes the central step of recombination and repair. The protein was crystallized using the hanging-drop vapour-diffusion method with PEG as a precipitant. Two orthorhombic crystal forms I and II with the same space group P2(1)2(1)2(1) were obtained at pH 8.0 using PEG 3000 and PEG 550 monomethylether, respectively. The unit-cell parameters were a = 151, b = 174, c = 241 A for form I and a = 151, b = 176, c = 300 A for form II, indicating that the asymmetric unit contains more than 20 molecules.

A unique DNase activity shares the active site with ATPase activity of the RecA/Rad51 homologue (Pk-REC) from a hyperthermophilic archaeon

A RecA/Rad51 homologue from Pyrococcus kodakaraensis KOD1 (Pk-REC) is the smallest protein among various RecA/Rad51 homologues. Nevertheless, Pk-Rec is a super multifunctional protein and shows a deoxyribonuclease activity. This deoxyribonuclease activity was inhibited by 3 mM or more ATP, suggesting that the catalytic centers of the ATPase and deoxyribonuclease activities are overlapped. To examine whether these two enzymatic activities share the same active site, a number of site-directed mutations were introduced into Pk-REC and the ATPase and deoxyribonuclease activities of the mutant proteins were determined. The mutant enzyme in which double mutations Lys-33 to Ala and Thr-34 to Ala were introduced, fully lost both of these activities, indicating that Lys-33 and/or Thr-34 are important for both ATPase and deoxyribonuclease activities. The mutation of Asp-112 to Ala slightly and almost equally reduced both ATPase and deoxyribonuclease activities. In addition, the mutation of Glu-54 to Gln did not seriously affect the ATPase, deoxyribonuclease, and UV tolerant activities. These results strongly suggest that the active sites of the ATPase and deoxyribonuclease activities of Pk-REC are common. It is noted that unlike Glu-96 in Escherichia coli RecA, which has been proposed to be a catalytic residue for the ATPase activity, the corresponding residual Glu-54 in Pk-REC is not involved in the catalytic function of the protein.

Median lip fissures and their management

Median lip fissures are an uncommon condition and usually give rise to pain and episodes of bleeding. We report three cases of median lip fissures which were treated by surgical excision.

Oral self-mutilation by a 17-month-old child with Lesch-Nyhan syndrome

We report a 17-month-old boy who was a known case of Lesch-Nyhan syndrome and presented with self-inflicted oral ulcerations of his lips and cheeks. He had a normal complement of caries-free deciduous teeth. Initially a conservative approach was planned and a bite plate made, but as a result of poor compliance and persistent ulceration and after consultation with his parents it was decided to extract all deciduous teeth.

Intermittent mental paraesthesia in an edentulous mandible

A patient presenting with bilateral intermittent mental paraesthesia on wearing a lower denture on a very atrophic ridge was treated with an implant-retained overdenture which resolved her symptoms.

Characterization of a RecA/RAD51 homologue from the hyperthermophilic archaeon Pyrococcus sp. KOD1

The Pk-rec gene, encoding a RecA/RAD51 homologue from the hyperthermophilic archaeon Pyrococcussp. KOD1, was expressed in Escherichia coli. The recombinant Pk-REC was purified to homogeneity and was shown to be in a dimeric form. A striking property of the purified recombinant Pk-REC was the unusual DNase activity on both single- and double-stranded DNAs along with the ATPase activity. The reaction product of this DNase activity was mononucleotides. The optimum temperature and pH for the DNase activity were 60 degrees C and 8-8.5, respectively. In addition, the metal ion requirement for DNase activity was different from that for the ATPase activity. The protein exhibited no DNase activity in the presence of Zn2+ion, which was one of the most preferable divalent cations for ATPase activity. Another unique characteristic of the recombinant protein was that the reaction product of ATPase activity was AMP instead of ADP.Pk-REC may represent a common prototype of the RecA family proteins with high RecA-like activity.

A RecA/RAD51 homologue from a hyperthermophilic archaeon retains the major RecA domain only

A gene encoding a RecA/RAD51 homologue from a hyperthermophilic archaeon, Pyrococcus sp. KOD1 (Pk), was cloned, sequenced and expressed in Escherichia coli. The deduced 210-amino acid sequence was compared to homologues from bacteria (RecA), eukaryotes (RAD51, DMC1) and archaea (RadA). The entire protein from Pk (Pk-REC) basically corresponds to the essential central domain of its counterparts and lacks the two smaller RecA subdomains at the N- and C-termini. The sequence comparison suggests that Pk-REC represents a common prototype of RecA, RAD51, DMC1 and RadA, with higher enzymatic activity. Recombinant Pk-REC was fully active and complemented the ultraviolet light sensitivity of an E. coli recA mutant strain.

An abnormally acidic TATA-binding protein from a hyperthermophilic archaeon

The gene encoding the TATA-binding protein (PkTBP) from a hyperthermophilic archaeon, Pyrococcus sp. KOD1 (Pk), was cloned and sequenced. An open reading frame with homology to the conserved C-terminal core region of eukaryotic TBP was expressed in Escherichia coli. Specific DNA-binding activity of the recombinant PkTBP (190 amino acids, 21.36 kDa) was also demonstrated. Although it was composed of a structurally direct repeat sequence which is similar to eukaryotic TBP, the total net charge of archaeal TBP was amazingly negative (calculated isoelectric point (pI) was 4.66 and experimentally estimated pI was 4.8). A series of five Glu residues was found at the C terminus of archaeal TBP. These data strongly suggest that a positively charged protein is also involved in the transcription initiation event which might stabilize the structure of the genomic DNA under high-growth-temperature conditions.