MyMedR

Displaying publications 21 - 40 of 43 in total

Abstract:

Sort:

Surface active complexes formed between keratin polypeptides and ionic surfactants

Pan F, Lu Z, Tucker I, Hosking S, Petkov J, Lu JR

J Colloid Interface Sci, 2016 Dec 15;484:125-134.
PMID: 27599381 DOI: 10.1016/j.jcis.2016.08.082

Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C12TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes.

Matched MeSH terms: Keratins/isolation & purification; Keratins/chemistry*
Fulltext NTCU induced pre-malignant and malignant stages of lung squamous cell carcinoma in mice model

Zakaria MA, Rajab NF, Chua EW, Selvarajah GT, Masre SF

Sci Rep, 2021 Nov 18;11(1):22500.
PMID: 34795360 DOI: 10.1038/s41598-021-01988-8

Mice have served as an excellent model to understand the etiology of lung cancer for years. However, data regarding dual-stage carcinogenesis of lung squamous cell carcinoma (SCC) remain elusive. Therefore, we aim to develop pre-malignant (PM) and malignant (M) lung SCC in vivo using N-nitroso-tris-chloroethylurea (NTCU). BALB/C mice were allotted into two main groups; PM and M groups which received treatment for 15 and 30 weeks, respectively. Then, the mice in each main group were allotted into three groups; control, vehicle, and cancer (n = 6), which received normal saline, 70% acetone, and 0.04 M NTCU by skin painting, respectively. Histopathologically, we discovered a mix of hyperplasia, metaplasia, and dysplasia lesions in the PM group and intracellular bridge; an SCC feature in the M group. The M group was positive for cytokeratin 5/6 protein which confirmed the lung SCC subtype. We also found significantly higher (P

Matched MeSH terms: Keratins/metabolism
Fulltext Solitary fibrous tumour of the submandibular region: a rare entity

Noor Liza Ishak, Primuharsa Putra Sabir Athar Husin, Suria Hayati Md Pauzi, Isa Mohd Rose, Mohd Razif Mohamad Yunus

Malaysian Journal of Medicine and Health Sciences, 2016;12(2):53-55.
MyJurnal

Solitary fibrous tumours of the head and neck region are
extremely rare. The clinical diagnosis is often difficult to
establish, and this lesion may be indistinguishable from other
soft tissue neoplasms. An 18-year old Chinese gentleman
presented with a painless right submandibular swelling which
was increasing in size for eight months. A computed
tomography scan showed a well-defined solid mass measuring
about 2.0 x 2.96 cm in the submandibular region. The tumour
was resected and was confined within its capsule.
Immunohistochemical staining was strongly positive for CD34,
CD 99, and vimentin and negative for desmin, smooth muscle
actin (SMA), cytokeratin, S100 and CD68. The microscopic and
immunohistochemical profile were compatible with solitary
fibrous tumour. Distinguishing solitary fibrous tumours from
various spindle neoplasms can be difficult. In view of the
resemblance, immunohistochemical staining can help
differentiate solitary fibrous tumour from spindle neoplasm.

Matched MeSH terms: Keratins
Extraction and application of keratin from natural resources: a review

Chilakamarry CR, Mahmood S, Saffe SNBM, Arifin MAB, Gupta A, Sikkandar MY, et al.

3 Biotech, 2021 May;11(5):220.
PMID: 33968565 DOI: 10.1007/s13205-021-02734-7

Over recent years, keratin has gained great popularity due to its exceptional biocompatible and biodegradable nature. It has shown promising results in various industries like poultry, textile, agriculture, cosmetics, and pharmaceutical. Keratin is a multipurpose biopolymer that has been used in the production of fibrous composites, and with necessary modifications, it can be developed into gels, films, nanoparticles, and microparticles. Its stability against enzymatic degradation and unique biocompatibility has found their way into biomedical applications and regenerative medicine. This review discusses the structure of keratin, its classification and its properties. It also covers various methods by which keratin is extracted like chemical hydrolysis, enzymatic and microbial treatment, dissolution in ionic liquids, microwave irradiation, steam explosion technique, and thermal hydrolysis or superheated process. Special emphasis is placed on its utilisation in the form of hydrogels, films, fibres, sponges, and scaffolds in various biotechnological and industrial sectors. The present review can be noteworthy for the researchers working on natural protein and related usage.

Matched MeSH terms: Keratins
An immunohistochemical study of the lining epithelium of odontogenic keratocyst

Siar CH, Ng KH

J Nihon Univ Sch Dent, 1995 Sep;37(3):163-9.
PMID: 7490610

The lining epithelium of 15 cases of odontogenic keratocyst (OKC) was evaluated immunohistochemically. The peroxidase-antiperoxidase technique was applied to study the distribution of polyclonal keratin and S-100 protein while the indirect method was used to examine monoclonal vimentin and desmin reactivity. Consistent positive keratin staining was revealed in the lining epithelium of all 15 OKCs with additional intense staining in the stratum corneum. None of the cases showed vimentin or desmin reactivity within the lining epithelium elements. One of the 15 cysts studied showed positive S-100 protein staining in the nuclei of the lining epithelial cells. The pertinent literature on the immunophenotyping of the lining epithelium of OKC is reviewed.

Matched MeSH terms: Keratins/analysis
'Combined ameloblastoma and odontogenic keratocyst' or 'keratinising ameloblastoma'

Siar CH, Ng KH

Br J Oral Maxillofac Surg, 1993 Jun;31(3):183-6.
PMID: 7685634

Four cases of either combined occurrence of ameloblastoma and odontogenic keratocyst or a rare keratinising variant of ameloblastoma are presented. The cardinal histomorphologic characteristics are simultaneous occurrence of ameloblastomatous epithelial islands with central keratinisation and multiple keratinising cysts. Immunohistochemically the tumour elements were keratin positive and occasionally S-100 protein and desmin positive. Major differential diagnosis of these neoplasms are discussed.

Matched MeSH terms: Keratins/analysis
Unusual granular cell odontogenic tumor. Report of two undescribed cases with features of granular cell ameloblastoma and plexiform granular cell odontogenic tumor

Siar CH, Ng KH

J Nihon Univ Sch Dent, 1993 Jun;35(2):134-8.
PMID: 7692017

Granular cell ameloblastoma (GCA) is a well recognized variant of follicular ameloblastoma with extensive granular cell change. In contrast, plexiform granular cell odontogenic tumor (PGCOT) is a rare and recently described lesion characterized histologically by a monophasic plexiform pattern of granular cells. In this paper, two cases of an unusual granular cell odontogenic tumor exhibiting combined features of these two entities are described along with their immunohistochemical characteristics. The granular cells of both the GCA and PGCOT areas showed similar patterns of expression for keratin and S-100, which differed from those of typical ameloblastoma. No reactivity for desmin or vimentin was noted. The histomorphologic and immunohistochemical features of these hybrid tumors suggest that the granular cells present have a common origin, most probably the odontogenic epithelium.

Matched MeSH terms: Keratins/analysis
Patterns of expression of intermediate filaments and S-100 protein in desmoplastic ameloblastoma

Siar CH, Ng KH

J Nihon Univ Sch Dent, 1993 Jun;35(2):104-8.
PMID: 7692015

Seventeen cases of desmoplastic ameloblastoma were examined immunohistochemically. Immunoperoxidase techniques were applied for detection of keratin, desmin, vimentin and S-100 protein expression in these tumors. The tumor epithelium of desmoplastic ameloblastoma exhibited weak, focal, inconstant keratin staining, weak, variable expression of S-100 protein, desmin immunoreactivity of mild to moderate intensity and vimentin non-reactivity. The pertinent literature on the immunohistochemistry of ameloblastomas is briefly reviewed.

Matched MeSH terms: Keratins/analysis
Orthokeratinised odontogenic keratocysts in Malaysians

Siar CH, Ng KH

Br J Oral Maxillofac Surg, 1988 Jun;26(3):215-20.
PMID: 2456095

The records of the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, Malaysia, were reviewed for the incidence of odontogenic keratocysts of the orthokeratinised variety, during the 20-year-period, 1967 to 1986. Nine cases were found. The clinical, histological and radiological features of these cases are reported. Many features were similar to previous reports of this entity but a peak incidence in the second decade of life, an almost even distribution in the maxilla and mandible, and a distinct predilection for the Chinese were observed. It is suggested that these features may be peculiar to Malaysians.

Matched MeSH terms: Keratins
Calcifying and keratinizing ameloblastoma of the maxilla

Siar CH, Ng KH

J Laryngol Otol, 1991 Nov;105(11):971-2.
PMID: 1722237

A case is described of ameloblastoma of maxilla presenting with numerous calcified keratin pearls. The significance of cellular variation in relation to the behavioural potential of the ameloblastoma in general is briefly discussed.

Matched MeSH terms: Keratins
Fulltext Treatments of chicken feather waste

Cheong, Chooi Wei, Siti Aqlima Ahmad, Ooi, Peck Toung, Phang, Lai Yee

The Pertanika Journal of Scholarly Research Reviews, 2017;3(1):32-41.
MyJurnal

Feather waste is a potential renewable source to recover valuable products because it is being a rich source of keratin proteins and amino acids. It can be used to make feather meal, fertilizer and yarn sizing agent. Various treatments have been used to recover the protein from chicken feathers as the keratinous feathers cannot be easily degraded due to its tough structure. This paper reviews the existing treatment methods used to hydrolyze chicken feathers. The treatment methods for feather hydrolysis such as physical, chemical, biological and combined treatments as well as their advantages and challenges are highlighted. The effects of these treatments on feather hydrolysis are complex and vary in regards to the performance of feather hydrolysis and product yielded. Hence, it is important to choose an appropriate treatment method since the type of treatment applied affects the product yielded qualitatively and quantitatively. In addition, the economic assessment and environmental impact of the choice of treatment should be considered also.

Matched MeSH terms: Keratins
Serum IgA cross-reactivity between glycine-alanine repeat sequence of EBNA-1 and keratin or collagen in nasopharyngeal carcinoma

Mathew A, Cheng HM, Sam CK, Prasad U

Clin. Immunol. Immunopathol., 1994 May;71(2):164-8.
PMID: 7514112

Inhibition studies were carried out to study possible cross-reactivity between a peptide fragment of the Epstein-Barr virus nuclear antigen, EBNA-1, and keratin/collagen. The 20-amino acid peptide (pAG), derived from a glycine-alanine repeat region of EBNA-1, uniquely makes up about one-third of the viral protein and is a dominant IgA antigenic epitope in patients with nasopharyngeal carcinoma (NPC). A small percentage of normal human sera (NHS) also binds pAG and this reactivity is examined in this study. Ten percent (2/20) and 13.4% (2/15) of IgA-pAG-positive NPC sera and NHS, respectively, were significantly inhibited by keratin in a competitive ELISA system. Conversely, 31.6% (6/19) and 30.8% (4/13) of IgA-keratin-positive NPC sera and NHS, respectively, were significantly inhibited by pAG. This indicated minimum cross-reactivity between IgA serum antibodies to EBNA-1 and keratin. Using collagen as inhibitor, none of 18 and only 2/13 IgA-pAG-positive NPC sera and NHS, respectively, were inhibited. In the collagen ELISA system, only 2/19 (10.5%) and 4/25 (16%) of IgA-collagen-positive NPC sera and NHS, respectively, were inhibited with pAG. Therefore, cross-reactivity with collagen was also low. IgA-pAG-positive NHS may therefore not be a false positive phenomenon, but whether it may represent an early serological profile related to NPC carcinogenesis remains to be determined.

Matched MeSH terms: Keratins/immunology*
Loss of PTEN expression is associated with IGFBP2 expression, younger age, and late stage in triple-negative breast cancer

Dean SJ, Perks CM, Holly JM, Bhoo-Pathy N, Looi LM, Mohammed NA, et al.

Am J Clin Pathol, 2014 Mar;141(3):323-33.
PMID: 24515759 DOI: 10.1309/AJCPR11DEAYPTUSL

OBJECTIVES: To investigate the association between PTEN loss and IGFBP2 expression in a series of triple-negative breast cancers and to relate this expression to basal cytokeratin expression and clinicopathologic features.
METHODS: One hundred and one formalin-fixed and paraffin-processed triple-negative breast cancer cases from the University of Malaya Medical Centre were tested immunohistochemically for cytokeratins 5/6 and 14, PTEN, and IGFBP2. The resulting slides were scored for proportion and intensity of staining.
RESULTS: Loss of tumor nuclear and cytoplasmic staining for PTEN occurred in 48.3% of cases and was significantly associated with younger age at diagnosis (47 years compared with 57 years in those without PTEN loss; P = .005). Independent predictors of PTEN loss were late stage at presentation (P = .026), cytokeratin 5/6 positivity (P = .028), and IGFBP2 expression (P = .042). High levels of IGFBP2 expression were seen in 32% of cases; an independent predictor of high levels was cytokeratin 14 negativity (P = .005). PTEN loss and high levels of IGFBP2 expression were associated with poorer survival, but neither of these trends was significant.
CONCLUSIONS: PTEN loss is a frequent event in triple-negative breast cancers and is significantly associated with younger age at onset of breast cancer, late stage, and IGFBP2 expression.

Matched MeSH terms: Keratins/metabolism
Molecular strategies to increase keratinase production in heterologous expression systems for industrial applications

Yahaya RSR, Normi YM, Phang LY, Ahmad SA, Abdullah JO, Sabri S

Appl Microbiol Biotechnol, 2021 May;105(10):3955-3969.
PMID: 33937928 DOI: 10.1007/s00253-021-11321-y

Keratinase is an important enzyme that can degrade recalcitrant keratinous wastes to form beneficial recyclable keratin hydrolysates. Keratinase is not only important as an alternative to reduce environmental pollution caused by chemical treatments of keratinous wastes, but it also has industrial significance. Currently, the bioproduction of keratinase from native keratinolytic host is considered low, and this hampers large-scale usage of the enzyme. Straightforward approaches of cloning and expression of recombinant keratinases from native keratinolytic host are employed to elevate the amount of keratinase produced. However, this is still insufficient to compensate for the lack of its large-scale production to meet the industrial demands. Hence, this review aimed to highlight the various sources of keratinase and the strategies to increase its production in native keratinolytic hosts. Molecular strategies to increase the production of recombinant keratinase such as plasmid selection, promoter engineering, chromosomal integration, signal peptide and propeptide engineering, codon optimization, and glycoengineering were also described. These mentioned strategies have been utilized in heterologous expression hosts, namely, Escherichia coli, Bacillus sp., and Pichia pastoris, as they are most widely used for the heterologous propagations of keratinases to further intensify the production of recombinant keratinases adapted to better suit the large-scale demand for them. KEY POINTS: • Molecular strategies to enhance keratinase production in heterologous hosts. • Construction of a prominent keratinolytic host from a native strain. • Patent analysis of keratinase production shows rapid high interest in molecular field.

Matched MeSH terms: Keratins
Characterization of keratin microparticles from feather biomass with potent antioxidant and anticancer activities

Sharma S, Gupta A, Chik SMST, Kee CG, Mistry BM, Kim DH, et al.

Int J Biol Macromol, 2017 Nov;104(Pt A):189-196.
PMID: 28596005 DOI: 10.1016/j.ijbiomac.2017.06.015

In the present study chicken feathers were hydrolyzed by chemical treatment in alkaline conditions. The pH value of feather hydrolyzed solution was amended accordingly the iso-electric precipitation. Two types of keratin microparticles KM1, KM2 were synthesized under acidic conditions at 3.5 and 5.5pH respectively. The synthesized keratin microparticles possessed uniform and round surface by scanning electron microscopy (SEM). The thermal degradation of microparticles were examined by thermogravimetry (TGA). Fourier transform infrared spectroscopy (FTIR) revealed that the extracted keratin retained the most of protein backbone. The microparticles were screened for their in vitro anticancer activities by SRB bioassay towards HeLa, SK-OV-3 and A549 cancer cell lines. Futhermore, their cytotoxicity towards healthy cell lines was analyzed having Malin Darby canine kidney (MDCK) cell lines along with in vitro antioxidant activity using DPPH and ABTS methods KM1 and KM2 showed 200.31±1.01 and 139.73±0.94, 214.16±0.29 and 153.92±0.61, 328.92±3.46 and 200.33±2.48μg/mL of IC50 levels against HeLa, SK-OV-3, and A549 cell lines, respectively. Moreover, KM1 and KM2 demonstrated significant antioxidant potency with IC50 levels 13.15 and 9.02μg/mL as well as 8.96 and 5.60μg/mL in DPPH and ABTS radical scavenging bioassay, respectively.

Matched MeSH terms: Keratins/pharmacology*; Keratins/chemistry*
Cannon's disease: clinical and diagnostic implications: a case report

Ram S, Siar CH

Dent Update, 2004 Nov;31(9):557-9.
PMID: 15612463

Cannon's disease or white sponge naevus is a relatively rare genetically determined skin disorder. It is inherited as an autosomal dominant trait that displays a high degree of penetrance and expressivity. This article describes cases of Cannon's disease in a mother and her son.

Matched MeSH terms: Keratins/genetics
A clinicopathological and immunohistochemical study of the calcifying epithelial odontogenic tumour (Pindborg tumour) in Malaysians

Ng KH, Siar CH

J Laryngol Otol, 1996 Aug;110(8):757-62.
PMID: 8869610

We reviewed the clinicopathological characteristics of 13 cases of calcifying epithelial odontogenic tumour (CEOT) (Pindborg tumour) diagnosed in the Division on Stomatology, Institute for Medical Research, Kuala Lumpur, over a 29-year period. There were eight female and five male patients. These consisted of eight (61.5 per cent) Malays, three (23.1 per cent) Chinese, one (7.7 per cent) Indian and one (7.7 per cent) Melanau. Their ages at presentation ranged from 19-61 years (mean age, 31.8 years). There were 12 central and one peripheral CEOT. Of these, 76.9 per cent of cases were located in the maxilla, the remaining in the mandible. The commonest clinical diagnosis was a dentigerous cyst (66.7 per cent). Enucleation was the main mode of treatment. Histologically, sheets and strands of polyhedral epithelial cells containing eosinophilic, homogeneous globules with Liesegang rings were observed. One case also showed extensive calcification and clear cell differentiation. Immunohistochemistry revealed a variable keratin staining of the CEOT epithelium, confirming its heterogeneity.

Matched MeSH terms: Keratins/analysis
Fulltext The eyes do not see what the mind does not know: an underreported feature in mature cystic teratoma of the ovary

Wong, Y.P., Tan, G.C.

Medicine & Health, 2018;13(2):223-228.
MyJurnal

Mature cystic teratoma is the commonest ovarian germ cell tumour which accounts for 70% of all benign ovarian neoplasms in the reproductive age groups. Being a pluripotent germ cell tumour, mature cystic teratoma has at least two out of three mature embryonic germ cell components: ectoderm, mesoderm and endoderm. The presence of multiple cystic spaces within the tumour wall, also known as pneumatosis cystoides-like appearance is rarely described but a characteristic feature in cystic teratoma of the ovary. Currently, there is little information concerning the mechanism of its formation. Herein, we described an unusual case of ovarian mature cystic teratoma in a 31-year-old pregnant female with multiple sieve-like areas resembling pneumatosis cystoides of the intestine. Macroscopic and histological examination of the ovary revealed features diagnostic of mature cystic teratoma. Intriguingly, multiple cystic spaces of variable sizes were found within the cyst wall histologically. They were lined partially or completely by foamy histiocytes and foreign body type multinucleated giant cells, exhibiting strong CD68 immunoreactivity. Vascular endothelial markers (CD31 and CD34) and epithelial marker (cytokeratin AE1/AE3) were negative. A diagnosis of mature cystic teratoma with pneumatosis cystoides-like feature was rendered. The patient was discharged well with no signs and symptoms of early labour. The etiopathogenesis of this intriguing histological feature is briefly discussed in this article.

Matched MeSH terms: Keratins
Human cytokeratin 1 plays a role in the interaction of Pteropine orthoreovirus with Hek293 cells but not HeLa cells

Siew ZY, Tan YF, Iswara RP, Wong SF, Wong ST, Tan BK, et al.

Microbes Infect, 2024;26(1-2):105243.
PMID: 38380604 DOI: 10.1016/j.micinf.2023.105243

Pteropine orthoreovirus (PRV) causes respiratory tract infections in humans. Despite its emergence as a zoonotic and respiratory virus, little is known about its cell tropism, which hampers progress in fully understanding its pathogenesis in humans. Hek293 cells are most susceptible to PRV infection, while HeLa cells are the least. Human cytokeratin 1 (CK1) was identified as the protein that interacts with PRV. The immunofluorescence assay and qPCR results revealed prior treatment with anti-CK1 may provide Hek293 cells protection against PRV. The KRT1-knockout Hek293 cells were less susceptible to PRV infection. Further study into the pathogenesis of PRV in humans is needed.

Matched MeSH terms: Keratins
Nasopharyngeal undifferentiated carcinoma with sarcomatoid features: Pitfalls in the immunohistochemistry

Lee M, Son HJ, Kim NY, Kim SJ, Yu IK

Malays J Pathol, 2019 Aug;41(2):201-206.
PMID: 31427557

We present a case of an undifferentiated subtype of non-keratinizing squamous cell carcinoma (NK-SCC) with sarcomatoid features in the nasopharynx in a 69-year-old man who was difficult to diagnose due to spindle-shaped malignant cells. He was admitted because of a right nasal obstruction and right headache, and imaging revealed a heterogeneously enhanced irregularly shaped mass at the nasopharynx. Histopathologically, the tumour was partially organised, and the tumour cells were epithelioid or spindle-shaped. Initially, we erroneously diagnosed the tumour as an angiosarcoma owing to its false-negative immunoreaction for cytokeratins and a mistaken interpretation for CD31. After in situ hybridization for Epstein-Barr virus was positive, a consultation and additional immunostaining (including re-staining for cytokeratin with varying dilutions) were performed, and the diagnosis was revised to NK-SCC with sarcomatoid features. We believe that sarcomatoid features may be observed in nasopharyngeal carcinoma and in this case, immunostaining using various epithelial markers is necessary and careful attention should be paid to the interpretation of immunostaining.

Matched MeSH terms: Keratins

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links