Lovastatin/SN38 co-loaded liposomes amplified ICB therapeutic effect via remodeling the immunologically-cold colon tumor and synergized stimulation of cGAS-STING pathway

Current immune checkpoint blockade (ICB) immunotherapeutics have revolutionized cancer treatment. However, many cancers especially the "immunologically cold" tumors, do not respond to ICB, prompting the search for additional strategies to achieve durable responses. The cGAS-STING pathway, as an essential immune response pathway, has been demonstrated for a potent target to sensitize ICB immunotherapy. However, the low efficiency of conventional STING agonists limits their clinical application. Recent studies have shown that DNA topoisomerase I (TOPI) inhibitor chemodrug SN38 can activate the cGAS-STING pathway and induce an immune response through DNA damage, while the traditional statins medication lovastatin was found to inhibit DNA damage repair, which may in turn upregulate the damaged DNA level. Herein, we have developed a liposomal carrier co-loaded with SN38 and lovastatin (SL@Lip), which can be accumulated in tumors and efficiently released SN38 and lovastatin, addressing the problem of weak solubility of these two drugs. Importantly, lovastatin can increase DNA damage and enhance the activation of cGAS-STING pathway, coordinating with SN38 chemotherapy and exhibiting the enhanced combinational immunotherapy of PD-1 antibody by remodeling the tumor microenvironment in mouse colorectal cancer of both subcutaneous and orthotopic xenograft models. Overall, this study demonstrates that lovastatin-assisted cGAS-STING stimulation mediated by liposomal delivery system significantly strengthened both chemotherapy and immunotherapy of colorectal cancer, providing a clinically translational strategy for combinational ICB therapy in the "immunologically cold" tumors.

Cocrystallization of Gefitinib Potentiate Single-Dose Oral Administration for Lung Tumor Eradication via Unbalancing the DNA Damage/Repair

Gefitinib (GEF) is a clinical medication for the treatment of lung cancer targeting the epidermal growth factor receptor (EGFR). However, its efficacy is remarkably limited by low solubility and dissolution rates. In this study, two cocrystals of GEF with co-formers were successfully synthesized using the recrystallization method characterized via Powder X-ray Diffraction, Fourier Transform Infrared Spectroscopy, and 2D Nuclear Overhauser Effect Spectroscopy. The solubility and dissolution rates of cocrystals were found to be two times higher than those of free GEF. In vitro cytotoxicity studies revealed that the cocrystals enhanced the inhibition of cell proliferation and apoptosis in A549 and H1299 cells compared to free GEF. In mouse models, GEF@TSBO demonstrated targeted, safe, and effective antitumor activity with only one-dose administration. Mechanistically, the GEF cocrystals were shown to increase the cellular levels of damaged DNA, while potentially downregulating PARP, thereby impairing the DNA repair machinery and leading to an imbalance between DNA damage and restoration. These findings suggest that the cocrystallization of GEF could serve as a promising adjunct to significantly enhance the physicochemical and biopharmaceutical performance for lung cancer treatment, providing a facial strategy to improve GEF anticancer efficiency with high bioavailability that can be orally administrated with only one dose.

Impact of L-Pyroglutamic Acid on the Solubility of Puerarin: Preparation, Solid-State Characterization and Physicochemical Evaluation of Puerarin-L-Pyroglutamic Acid Co-Crystal

Abstract. Drug solubility plays a significant role in the successful therapeutic formulation. The objective of this work is enhancing the water solubility of Puerarin. We successfully synthesized a novel crystalline phase co-crystal of Puerarin (PUE) with L-pyroglutamic acid (PG) via recrystallization method and characterized by various solid-state characterization techniques. PXRD pattern shows the crystallinity phase co-crystal. The DSC analysis of co-crystal shows change in the thermal behavior compared with a pure form of PUE and PG. The FT-IR analysis shows change in the functional group frequency due to H-bonding interaction between PUE and PG molecule. The solubility of Pure PUE and co-crystal investigated in Pure water, pH 6.8 phosphate buffer solution and pH 1.2 acidic medium.  co-crystal reveals improved solubility when compared with pure form of PUE. The time-dependent in vitro dissolution rate of co-crystal was more significant compared to the pure commercial form of PUE, demonstrating that co-crystal could be used as a useful product for pharmaceutical formulation with enhance properties. Resumen. La solubilidad de un fármaco juega un papel importante en su formulación farmacútica final. El objetivo de este trabajo es incrementar la solubilidad acuosa del compuesto puerarina. En este sentido, reportamos la síntesis de una nueva matriz cristalina, formada a través de la recristalización de una mezcla de puerarina (PUE) y ácido L-piroglutámico (PG). El patron de análisis DSC del co-cristal mostró un cambio términco comparado con PUE y PG puros. El análisis detallado del co-cristal por medio de infrarrojo (FT-IR) mostró un cambio en la fecuancia de absorción en la región característica de enlaces de hidrógeno entre PUE y PG. Comparamos la solubilidad de una muestra pura de PUE y la de una muestra del co-cristal en agua, en un buffer de fosfátos pH 6.8, y en medio acídico a pH 1.2. La muestra del co-cristal mostró un aumento significativo en la solubilidad acuosa, comparada con la de PUE en todos los medios. Además, el perfil de disolución de una mestra del co-cristal fue significativamente mayor que el perfil de disolución de PUE, demostrando que esta forma de co-cristalización es un procedimiento altamente efectivo para incrementar la solubilidad acuosa de PUE.  

The protective mechanism of a novel polysaccharide from Lactobacillus-fermented Nostoc commune Vauch. on attenuating cadmium-induced kidney injury in mice

A novel polysaccharide (NCVP-F) from Lactobacillus-fermented Nostoc commune Vauch. was obtained to investigate its underlying mechanism in cadmium-induced kidney injury. Results indicated that in comparison with NCVP, NCVP-F with lower molecular weight of 365.369 kDa, exhibited higher mole percentage of Man and Glc-UA, whereas slightly lower mole percentage of other monosaccharides. NCVP-F is a α-pyran polysaccharide similar to NCVP. Meanwhile, NCVP-F can more effectively alleviate hepatorenal injury (ALT, AST, TG, BUN and SCr) and kidney tissue lesions in Cd-injured mice model by increasing antioxidant enzyme activity (SOD, GSH and GSH-Px), inhibiting cytokines levels (IL-6, IL-1β, TNF-α and IL-18). In addition, NCVP-F effectively inhibited apoptosis proteins (Bax, cytochrome c, a-caspase-9 and a-caspase-3) and enhanced anti-apoptotic protein (Bcl-2) probably via activating PI3K/AKT/mTOR pathway in the Cd-injury kidney. Furthermore, 16S rRNA sequencing results indicated that NCVP-F better enriched Lachnospiraceae, reduced Muribaculaceae, Alloprevotella and Blautia to regulate Cd-induced gut microbiota disorders, which was probably down-regulated 7 pathways including apoptosis and lipopolysaccharide biosynthesis, and up-regulated 63 pathways, such as carbohydrate metabolism and lipid metabolism. This study suggested that applying functional NCVP-F prepared by biotransformation with low molecular weight might be more beneficial.

A scientometrics study of the nanomedicines assisted in respiratory diseases

Nanomedicine has been extensively studied for its versatility and broad-spectrum applications of theranostics in the research of respiratory disease. However, to the best of our knowledge, a scientometrics study based on the scientific knowledge assay of the overall situation on nanomedicine applied in the research of respiratory disease has not been reported so far, which would be of major importance to relevant researchers. To explore and exhibit the research status and developing trend of nanomedicines deployed in basic or clinical research in respiratory disease, the research ecosystem and exciting subareas were profiled based on the massive data mining and visualization from the relevant works reported from 2006 to 2021. Data were collected from the Web of Science database. Data statistics software and bibliometric analysis software were employed to visualize the research trend and the relationship between respiratory diseases and nanomedicines in each representative direction. The cluster analysis and burst detections indicated that the improvement of drug delivery and vaccine developments are the up-to-date key directions in nanomedicines for respiratory disease research and treatments. Furthermore, we emphatically studied four branch areas in this field including COVID-19, nanotube, respiratory syncytial virus, and mRNA vaccine those are selected for in-depth mining and bibliometric coupling analysis. Research trends signify the future focuses will center on preventing respiratory diseases with mRNA vaccines using nanoparticle-based approaches. We anticipate our study will enable researchers to have the panorama and deep insights in this area, thus inspiriting further exploitations especially the nanobiomaterial-based systems for theranostic applications in respiratory disease treatment.

Levosulpiride for Premature Ejaculation: A Systematic Review and Meta-Analysis

Premature ejaculation (PE) is one of the major causes of sexual dysfunction. Levosulpiride is an off-label medicine used to treat PE, but no review on its efficacy exists. A systematic review and meta-analysis was performed to determine the efficacy of levosulpiride in treating PE. Databases PubMed, Science Direct, and Google Scholar were searched. Randomized control trials (RCTs) comparing levosulpiride with placebo or other medicine were selected. Odds ratio (OR) of improved intravaginal ejaculation latency time (IELT) was calculated. A total of 97 articles were retrieved from database search, of which only four RCTs containing 203 men met the selection criteria. All four RCTs were included in systematic review while only two were included in meta-analysis. A high selection and detection bias was found in both of these studies. Meta-analysis also showed the odds of improving IELT in PE patients using levosulpiride to be significantly higher (p < .05) compared with those who used placebo, OR: 100.81, 95% confidence interval (CI) [13.12-774.90], I² = 0%. Odds of improving IELT for > 5 min (500% improvement) were also significantly higher (p < .05) compared with the placebo groups (OR: 38.88, 95% CI [5.12-295.29], I² = 0%). The odds of improving IELT for > 1 min, but < 5 min were also significantly higher (p < .05) than placebo groups (OR: 32.84, 95% CI [4.15-259.75], I² = 0%). Levosulpiride improved IELT, but even so, limited studies are available on this topic. Additional research is thus required to support the present review's findings.

Haphephobia: a rare specific phobia of being touched

Introduction

Haphephobia is a morbid fear of being touched or touching. The symptoms of Haphephobia are very similar to other specific phobias.

Objectives

Presentation of a case of haphephobia due to childhood sexual abuse

Methods

Mrs. X., A 22-year-old Bangladeshi female, presents to the psychiatric consult service with an intense fear of being touched by her husband. She told that whenever her husband comes closer to her, her heart starts to pound fast, she feels discomfort in the chest, a burning sensation on her whole body, and loses control over the environment. Furthermore, she can’t sleep properly for the fear of being touched. Her in-laws’ parents concluded that some ‘evil spirits’ might cause the symptoms. So her husband brought her to a Psychiatrist. On an in-depth assessment session, ensuring all the confidentiality issues, she told the Psychiatrist that she has a history of brutal sexual abuse followed by the threat to kill her by her stepfather at the age of fourteen.

Results

After a thorough medical workup and history gathering, her consultant psychiatrist could elucidate the source of the presenting picture and told her that she developed haphephobia, and suggested taking psychotherapy along with prescribed medicines.

Conclusions

Fear of being touched is a particularly difficult fear to cope with. Patients with haphephobia after sexual assault should be handled very cautiously by the experts keeping confidentiality issues in mind. Cognitive-behavior therapy, Exposure therapy, Virtual reality exposure therapy, practicing mindfulness, using daily coping strategies, and medications like beta-blockers, anxiolytics, antidepressants can help a person to overcome haphephobia.

Disclosure

No significant relationships.

Discovery of a novel antibacterial protein CB6-C to target methicillin-resistant Staphylococcus aureus

Given a serious threat of multidrug-resistant bacterial pathogens to global healthcare, there is an urgent need to find effective antibacterial compounds to treat drug-resistant bacterial infections. In our previous studies, Bacillus velezensis CB6 with broad-spectrum antibacterial activity was obtained from the soil of Changbaishan, China. In this study, with methicillin-resistant Staphylococcus aureus as an indicator bacterium, an antibacterial protein was purified by ammonium sulfate precipitation, Sephadex G-75 column, QAE-Sephadex A 25 column and RP-HPLC, which demonstrated a molecular weight of 31.405 kDa by SDS-PAGE. LC–MS/MS analysis indicated that the compound was an antibacterial protein CB6-C, which had 88.5% identity with chitosanase (Csn) produced by Bacillus subtilis 168. An antibacterial protein CB6-C showed an effective antimicrobial activity against gram-positive bacteria (in particular, the MIC for MRSA was 16 μg/mL), low toxicity, thermostability, stability in different organic reagents and pH values, and an additive effect with conventionally used antibiotics. Mechanistic studies showed that an antibacterial protein CB6-C exerted anti-MRSA activity through destruction of lipoteichoic acid (LTA) on the cell wall. In addition, an antibacterial protein CB6-C was efficient in preventing MRSA infections in in vivo models. In conclusion, this protein CB6-C is a newly discovered antibacterial protein and has the potential to become an effective antibacterial agent due to its high therapeutic index, safety, nontoxicity and great stability.

Characterization and complete genome analysis of Bacillus velezensis CB6 revealed ATP synthase subunit α against foodborne pathogens

Given the serious threat of foodborne multidrug-resistant bacteria to animals and humans, finding an effective antibacterial compound has always been an important topic for scientists. Here, from the soil of Changbaishan, we have identified a bacterium that can inhibit the growth of Staphylococcus aureus. Nr genome database analysis and phylogenetic analysis showed that strain CB6 belongs to Bacillus velezensis. We found that the crude extract of strain CB6 has broad-spectrum antibacterial activity against foodborne pathogens. In addition, we showed that the crude extract loses antibacterial activity after treatment with papain. Next, strain CB6 was purified using ammonium sulfate precipitation, a Sephadex G-75 gel filtration column and high-performance liquid chromatography system (HPLC). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis indicated that the antibacterial compound was the protein ATP synthase subunit α (ATP-1), with a molecular weight of 55.397 KDa. Moreover, we reported the complete genome sequence of strain CB6, which is composed of a unique circular 3,963,507 bp chromosome with 3749 coding genes and a G + C content of 46.53%. The genome contained 12 gene clusters with antibacterial functions, which constituted over 20.947% of the complete genome. Of note, the amino acid sequence encoding the ATP-1 protein in the strain CB6 genome was identified. In addition to these findings, we speculate that the ATP-1 protein may provide energy for secondary metabolites, which in turn will improve the antibacterial activity of the secondary metabolites. All the above important features make the ATP-1 as a potential candidate for the development of new antibacterial drugs and food preservatives in the future.

Preparation, Characterization and Pharmacokinetic Study of N-Terminal PEGylated D-Form Antimicrobial Peptide OM19r-8

Recently, new cationic antibacterial peptide OM19R has been designed with low minimum inhibitory concentration (MIC) values against some gram-negative bacteria, such as Escherichia coli, Salmonella, and Shigella. However, this hybrid peptide, like most antibacterial peptides, has low enzyme stability and short half-life, which, in turn, increases the drug's cost. In this study, an antibacterial peptide (OM19r-8) was obtained containing some D-Arg amino acids. The new preparations were carried out through the replacement of l-Arginine by d-Arginine and the addition of PEG chains. Firstly, eight OM19r series of antibacterial peptides were obtained by designing D-Arg. Then, a polyethylene glycol-modified product mPEG₅-butyrALD-OM19r-8 (mPEG₅-OM19r-8) was isolated and purified by reverse-phase high-performance liquid chromatography (RT-HPLC). The enzyme stability test showed that the resistance of antibacterial peptide OM19r-8 to protease degradation increased by 4-32-fold. Moreover, the Time-kill studies showed that the germicidal kinetics curves of mPEG₅-OM19r-8 and OM19r-8 to Escherichia coli had a similar trend, thus suggesting that PEG modification has an acceptable effect on the activity of the original peptide. Furthermore, the elimination of half-life (28.09 ± 2.81min) of mPEG₅-OM19r-8, and the area under the drug concentration-time curve (2686.48 ± 651.36min∗ug/ml) was significantly prolonged. The current study demonstrates an example that optimizes the AMP by utilizing L-to-D amino acid replacement and including PEG chains. These results provide useful data for the clinical application of the mPEG₅-OM19r-8.

Serine protease inhibitor MDSPI16 ameliorates LPS-induced acute lung injury through its anti-inflammatory activity

A previous study described a novel serine protease inhibitor 16 from Musca domestica (MDSPI16), which inhibited the elastase and chymotrypsin. It also exhibited a potential anti-inflammatory activity for acute lung injury (ALI), while its effects on ALI are yet to be elucidated. The present study aimed to investigate the effects and the underlying mechanisms of MDSPI16 on lipopolysaccharide (LPS)-challenged mice and bone marrow neutrophils. The ALI model based on the results of LPS-induced mice demonstrated that MDSPI16 markedly reduced the infiltration of inflammatory cells, protein exudation in lung tissues, and downregulated the level of interleukin-6 (IL-6), IL-1β and tumor necrosis factor-α (TNF-α). Furthermore, the LPS-stimulated mouse bone marrow neutrophils model was employed to determine the role of MDSPI16. The cytokine levels were quantified by both the enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR). Consequently, the expression of IL-6, IL-1β, and TNF-α was found to be inhibited by MDSPI16 in a dose-dependent manner. Moreover, MDSPI16 also inhibited the mouse neutrophils nuclear factor-κB (NF-κB) signaling pathway, c-Jun N-terminal kinase (JNK) signaling pathway, ERK1/2 and AP-1 signaling pathway in addition to the expression of iNOS and COX-2 proteins, which in turn, might alleviate the release of pro-inflammatory cytokines during ALI. Therefore, MDSPI16 could be proposed as a potential and novel drug therapy for ALI.

Mean Tip-Apex Distance In Lag Screw Cut-Out After Dynamic Hip Screw Fixation Of Hip Fracture

BACKGROUND

To determine mean tip-apex distance after Dynamic Hip Screw fixation of intertrochanteric fracture.

METHODS

This descriptive cross-sectional study was conducted in the Department of Orthopaedics, Hayatabad Medical Complex, Peshawar from October 2015 to September 2016 on a total 285 patients.

RESULTS

A total of 285 patients were observed. Status of TAD among 285 patients was analysed as 171 (60%) patients had TAD ranged 15 mm to 20 mm, 91(32%) patients had TAD ranged 21 mm to 25 mm, 23 (8%) patients had TAD ranged >25mm. Mean TAD was 18 mm with SD±7.45. Eight percent patients had screw cut out while 92% patients didn't had screw cut out.

CONCLUSIONS

To avoid lag screw cut out in dynamic hip screw for intertrochanteric fracture of hip the Tip apex distance must be accurate otherwise there will be cut out of lag screw.

Palladium-polymer nanoreactors for the aqueous asymmetric synthesis of therapeutic flavonoids

Polymeric core–shell micelles incorporating a chiral palladium pyridinooxazoline catalyst are presented as nanoreactors for the aqueous asymmetric synthesis of flavanones, a class of flavonoids, with therapeutic properties.

Thermal Conductivity of Some Major Building Materials in Saudi Arabia

The objective of this work was to measure the thermal conductivity of the more common building materials used in Saudi Arabia and compare the results with the data reported in handbooks These materials included seven types of clay bricks, one type of sandlime bricks, five types of concrete blocks and one type of pre fabricated wall The study shows that, although the thermal conductivities of these materials lie within the range of the values reported in handbooks, they are on the higher side of the range.

Prevalence of sensitization to food allergens and challenge proven food allergy in patients visiting allergy centers in Rawalpindi and Islamabad, Pakistan

In this study, we estimated the prevalence of food allergy in the adult allergic patients of Rawalpindi and Islamabad , Pakistan, based on self-report, skin prick test (SPT) and oral food challenge test (OFC). SPT was used for the estimation of sensitization to wheat, egg, milk, beef, chicken, mutton, fish, corn, lentils, rice, soya, peanut and banana. Among 689 patients, 39.19 % showed sensitivity to one or more foods, where, sensitization to wheat (156; 22.6 %) was highest, followed by egg (148; 21.48 %) and milk (138; 20.03 %). Sensitization to various proteins ranged between 15.53–15.97 %, while lentils, corn, rice, soya and peanut sensitization was 15.4, 16, 12.5, 12 and 11.5 % respectively. Only 7.1 % patients were SPT positive for banana allergen. SPT was performed in patients with self-reported food allergy (341/689) and also with no self-reported history of food allergy (348/689). SPT results were positive in 69.8 % of the self-report group, whereas, in the patients with no self-reported food allergy 9.2 % were found sensitized to one or more tested food allergens. 101 patients were recruited for OFC, 61 % of these were confirmed of food allergy. The prevalence of food allergy in the study population was 9 %. Food specific OFC results show that wheat allergy is affecting 1.6 % (95 % CI 0.9–2.84 %) of the total allergy patients, followed by egg allergy 1.31 % (95 % CI 0.70–2.47 %). Furthermore, corn allergy, rice allergy and peanut allergy were 1.02, 0.87 and 0.73 %, respectively. In conclusion, wheat allergy is the most prevalent, followed by egg, chicken, beef and fish allergy, respectively.

Outcome of ilizarov fixator in tibial non-union

OBJECTIVE

To evaluate the results of non-union of tibia treated with Ilizarov fixator.

METHODS

The case series was conducted at Hayatabad Medical Complex, Peshawar, from January 2012 to April 2015, and comprised consecutive patients with non-union of the tibia. Patients of either gender, with complex non-union of the tibia from the age of 18 to 65 years were included, while patients with intra-articular fractures, vascular injury, smokers and steroid users were excluded. Outcome of the treatment was graded by using the scoring system of Association for the Study and Application of Methods of Ilizarov.

RESULTS

There were 21 patients with a mean age of 40±13.89 years (range: 18-65 years). There were 7(33.3%) female and 14(66.6%) male patients. There were 14(66.6%) patients who had one previous surgery, 5(23.8%) had 2 surgeries and 2(9.5%) had 3. Bone results were excellent in 12(57.1%) patients, good in 6(28.6%) and fair in 3(14.3%). Functional results were excellent in 7(33.3%) patients, good in 9(42.9%), fair in 4(19%) and poor in 1(4.8%).

CONCLUSIONS

Ilizarov fixator gave good to excellent results in tibialnon-union, by eradicating the infection, filling the defect with bone transport, correcting the deformity and the limb length discrepancy.

Effectiveness of platelets rich plasma versus corticosteroids in lateral epicondylitis

OBJECTIVE

To compare the treatment modalities of lateral epicondylitis in terms of pain relief.

METHODS

The randomised controlled study was conducted at Hayatabad Medical Complex, Peshawar, Pakistan, from April 2013 to March 2014, and comprised cases of lateral epicondylitis. The patients were selected through consecutive sampling from the outpatient department and were randomly allocated to two equal groups; group A receiving corticosteroid injections, and group B receiving injection of platelet-rich plasma. The patients were followed up for three weeks to determine the effectiveness of intervention.

RESULTS

The 102 patients in the study were divided into two groups of 51(50%) each. The over mean age was 33.9±10.3 years. Mean age of patients in the corticosteroid group was 34.2±10.2 years and in the other group it was 33.6±10.5 years. Mean baseline visual analogue score in group A were 6.5±1.2 and in group B it was 6.7±1.4. In group A, 74.5% of patients presented in moderate pain category and 25.5% presented in severe pain category. In group B, 70.6% presented in moderate with 29.4% presented in severe pain category. On follow-up, the mean pain score in group A was 4.0±2.6 and in group B it was 3.5±2.61. Group A showed effectiveness in 52.9% patients and group B showed effectiveness in 82.3% (p=0.001).

CONCLUSIONS

PRP is an effective alternate to corticosteroid in the treatment of lateral epicondylitis (tennis elbow).

Three-dimensional profilometry of microlenses by phase shifting interferometery using nematic liquid crystal material filled cell as a phase modulator

In this paper, we report the use of a nematic liquid crystal material filled cell in transmission mode as a voltage controlled phase modulator for the characterization of microlenses. In one arm of the Mach-Zehnder interferometer, a nematic liquid crystal filled cell with DC voltage connection was placed, and in another arm of the interferometer microlenses with a 4-F imaging system were placed. Interference takes place between the light beams coming from the two arms of the Mach-Zehnder interferometer, one after passing through the nematic liquid crystal cell and another after passing through microlenses. Interference patterns were recorded by a CCD camera. By applying DC voltage to the nematic liquid crystal filled cell, various phase shifted interferograms were recorded, and from phase shifted interferograms, the shape and size of microlenses were determined. The results of the reconstructed profile of the microlenses are compared with white-light profilometry.

Group 1 Allergen Genes in Two Species of House Dust Mites, Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae): Direct Sequencing, Characterization and Polymorphism

Group 1 allergens of Dermatophagoides farinae (Der f 1) and D. pteronyssinus (Der p 1) dominate overall allergic responses in house dust mite allergy patients. The need for accurate identification and characterization of representative variants of group 1 allergens in any given geographic locality has been emphasized for development of appropriate allergen extracts. Regional amino acid sequence polymorphism has been described but the extent of this polymorphism is not well understood. Such data are completely absent for the USA and many other countries. Most previous studies used cDNA libraries generated by reverse transcriptase (RT-PCR) and/or primers amplifying shorter fragments of this gene. Using novel species-specific primers and direct PCR, we document group 1 allergen gene sequence polymorphism in populations of D. farinae and D. pteronyssinus from the USA and Pakistan. We report two novel introns (nt pos 87 and 291) in both species, and the absence of intron 3 in Der p 1. Thirteen silent and one novel non-synonymous mutation (Tryptophan W¹⁹⁷ to Arginine R¹⁹⁷) were detected in D. farinae. The potential medical significance of the latter mutation is discussed. Two haplotypes of the Der f 1 gene were identified, haplotype 1 (63%) was more frequent than haplotype 2 (18%). Polymorphism in Der f 1 displayed geographical localization, since both haplotypes were present in mite populations from Pakistan whereas haplotype 1 was observed only in the USA. In Der p 1, a silent mutation at nt (aa) position 1011(149) and four non-synonymous mutations at positions 589(50), 935(124), 971(136), 1268(215) were observed. These mutations were reported from many other geographic regions, suggesting that polymorphism in the Der p 1 gene is panmictic. The extent of polymorphism in both genes is substantially lower than that reported previously (0.10–0.16% vs 0.31–0.49%), indicating the need for careful evaluation of potential polymerase errors in studies utilizing RT-PCR.

Measurement of birefringence of nematic liquid crystal material by multiple-wavelength interferometry using nearly common-path single-stage Mach-Zehnder interferometer

We report the measurement of birefringence of nematic liquid crystal (NLC) material using multiple-wavelength interferometry. A nearly common path single-stage Mach-Zehnder interferometer was used for recording interferograms of high stability. The Fourier transform fringe analysis technique was used to reconstruct the two-dimensional phase maps of interferograms consisting of the entire active area of the liquid crystal cell. Change in phase as a function of applied voltage to a liquid-crystal cell was measured for blue, green, and red color laser light, keeping the temperature constant during the experiment. From the change in phase, the birefringence for three colors, i.e., red, green, and blue light, was determined. It is found that the birefringence of NLC material for red, green, and blue colors decreases with the increase in wavelength in the visible range. The present method is noncontact, nonmechanical scanning and highly stable due to a common path interferometer.

Group 10 allergens (tropomyosins) from house-dust mites may cause covariation of sensitization to allergens from other invertebrates

Group 10 allergens (tropomyosins) have been assumed to be a major cause of cross-reactivity between house-dust mites (HDMs) and other invertebrates. Despite all of the published data regarding the epidemiology, percent IgE binding and level of sensitization in the population, the role of tropomyosin as a cross-reactive allergen in patients with multiple allergy syndrome still remains to be elucidated. Homology between amino acid sequences reported in allergen databases of selected invertebrate tropomyosins was determined with Der f 10 as the reference allergen. The 66.9 and 54.4% identities were found with selected crustacean and insect species, respectively, whereas only 20.4% identity was seen with mollusks. A similar analysis was performed using reported B-cell IgE-binding epitopes from Met e1 (shrimp allergen) and Bla g7 (cockroach allergen) with other invertebrate tropomyosins. The percent identity in linear sequences was higher than 35% in mites, crustaceans, and cockroaches. The polar and hydrophobic regions in these groups were highly conserved. These findings suggest that tropomyosin may be a major cause of covariation of sensitization between HDMs, crustaceans, and some species of insects and mollusks.