Application of Single-Domain Antibodies (“Nanobodies”) to Laboratory Diagnosis

Pillay Tahir S.,Muyldermans Serge 대한진단검사의학회 2021 Annals of Laboratory Medicine Vol.41 No.6

Antibodies have proven to be central in the development of diagnostic methods over decades, moving from polyclonal antibodies to the milestone development of monoclonal antibodies. Although monoclonal antibodies play a valuable role in diagnosis, their production is technically demanding and can be expensive. The large size of monoclonal antibodies (150 kDa) makes their re-engineering using recombinant methods a challenge. Single-domain antibodies, such as “nanobodies,” are a relatively new class of diagnostic probes that originated serendipitously during the assay of camel serum. The immune system of the camelid family (camels, llamas, and alpacas) has evolved uniquely to produce heavy-chain antibodies that contain a single monomeric variable antibody domain in a smaller functional unit of 12–15 kDa. Interestingly, the same biological phenomenon is observed in sharks. Since a single-domain antibody molecule is smaller than a conventional mammalian antibody, recombinant engineering and protein expression in vitro using bacterial production systems are much simpler. The entire gene encoding such an antibody can be cloned and expressed in vitro. Single-domain antibodies are very stable and heat-resistant, and hence do not require cold storage, especially when incorporated into a diagnostic kit. Their simple genetic structure allows easy re-engineering of the protein to introduce new antigen-binding characteristics or attach labels. Here, we review the applications of single-domain antibodies in laboratory diagnosis and discuss the future potential in this area.

Case Report of a Laparoscopic Primary Diaphragmatic Repair in Acute Penetrating Trauma: Is It Within the Realm of an Acute Care Surgeon?

Pillay Yagan,Vetter Cheyenne 대한외상중환자외과학회 2021 Journal of Acute Care Surgery Vol.11 No.2

The laparoscopic repair of traumatic diaphragmatic injuries in the acute phase has not been well established. The current consensus view is an elective repair by a surgeon with an advanced laparoscopic skill set. This case report illustrates the position that with judicious patient selection an acute repair is not only possible but well within the realm of an acute care surgeon. Anterior diaphragmatic injuries with penetrating trauma can even be repaired primarily without the need for prosthetic reinforcement. It is hoped that this case report will add to the surgical armamentarium of the acute care surgeon.

A Comparative Theoretical Study of Au, Ag and Cu Adsorption on TiO₂ (110) Rutile Surfaces

Pillay, Devina,Wang, Yun,Hwang, Gyeong S. 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

The adsorption properties of Au, Ag and Cu on TiO_(2)(110) rutile surfaces are examined using density functional theory slab calculations within the generalized gradient approximation. We consider five and four different adsorption sites for the metal adsorption on the stoichiometric and reduced surfaces, respectively. The metal-oxide bonding mechanism and reactivity of metal atoms are also discussed based on the analyses of local density of states and charge density differences. This study predicts that Au atoms prefer to adsorb at the fourfold hollow site over the fivefold-coordinated Ti(5c)and in-plane and bridging O(2c) atoms with the adsorption energy of?0.6eⅤ. At this site, it appears that the covalent and ionic interactions with the Ti(5c) and the O(2c), respectively, contribute synergistically to the Au adsorption. At a neutral F^(0)_(x) center in the reduced surface, Au binds to the surface via a rather strong ionic interaction with surrounding sixfold-coordinated Ti(6c) atoms, and its binding energy is much larger than to the stoichiometric surface. On the other hand, Ag and Cu strongly interact with the surface bridgingO(2c) atoms, and the site between two bridging O(2c) atoms is predicted to be energetically the most favorable adsorption site. The adsorption energies of Ag and Cu at the B site are estimated to be ?1.2eⅤ, respectively. Unlike Au, the interaction of A and Cu with a vacancy defect is much weaker than with the stoichiometric surface.

A Case Report of a Bleeding Duodenal Gastro-Intestinal Stromal Tumor and its Emergent Management

Yagan Pillay,Oladapo Mabadeje 대한외상중환자외과학회 2021 Journal of Acute Care Surgery Vol.11 No.3

A gastrointestinal stromal tumor (GIST) arising in the duodenum is a rare subtype of mesenchymal tumor. GISTs have a reported incidence of 11.9–19.6 per million population and duodenal GISTs make up just 5% of these tumors. Common presentation of duodenal GISTs is through an upper gastrointestinal bleed, of which, they are responsible for less than 1% of all gastrointestinal bleeding. In an elective setting, surgical management remains the mainstay of treatment. In this Case Report, the emergent management of a localized duodenal resection was performed by an acute care surgeon, in an unstable patient. The risk factors for malignancy include tumor size and a high mitotic cell index. Tumor recurrence is determined by tumor size, tumor rupture, high mitotic cell index, a non-gastric location and gastrointestinal bleeding.

A Case Report of a Rare Aetiology of a Sigmoid Volvulus Involving a Congenital Omental Defect

Yagan Pillay,Vimal Naidoo 대한외상중환자외과학회 2024 Journal of Acute Care Surgery Vol.14 No.1

Sigmoid volvulus is a rare form of large bowel obstruction and makes up < 5% of all colonic obstruction. The commonest aetiologies include a lead point involving an intra or extra luminal mass such as amalignancy or a benign stricture or colonic dysmotility especially in the geriatric population. Rareaetiologies include a mesenteric defect, or as in this case report, a congenital omental defect acting as thelead point. This makes for an increasingly unusual case report, and we believe that this is the first suchreport in English language literature. The management remains the same, irrespective of the aetiology. Endoscopic bowel decompression in the acute phase is followed by definite surgical management with orwithout a primary surgical anastomosis.

Case Report of an Appendiceal Mucinous Neoplasm: A Rare Etiology for Appendicitis

Yagan Pillay,Olivia Boden 대한외상중환자외과학회 2023 Journal of Acute Care Surgery Vol.13 No.3

An appendiceal mucinous neoplasm is a rare condition with a clinical picture that can resemble appendicitis. Published reports have documented an incidence of 0.07-0.3% of all appendicectomies. The ubiquitous use of computerized tomography scans has helped plan surgical strategies as these patients may often require a right hemicolectomy in order to ascertain oncological clearance. This helps the clinician to avoid the complication of pseudomyxoma peritonei with its attendant increased mortality. In this case report the presence of a normal appendix base allowed for a laparoscopic intervention without having to resect the right hemi-colon. All published case reports to date have documented the involvement of the entire appendix. This case report is unique in the sparing of the proximal appendix.

A Rare Case of Sigmoid Intussusception due to Sigmoid Diverticula in a Patient with Concomitant Extensive Small Bowel Diverticula

Yagan Pillay,Adeyemi Laosebikan 대한외상중환자외과학회 2023 Journal of Acute Care Surgery Vol.13 No.2

Small intestinal diverticula is a rare occurrence, and their surgical management remains controversial due to the lack of a recognized classification system. Complications such as perforation and obstruction are treated surgically. Their etiology remains nebulous but theories such as damage to the Auerbach’s nerve plexus have been advanced as a possible cause. The concomitant presence of a sigmoid intussusception due to diverticular disease in the same patient is truly a rare occurrence. The vast majority of colonic intussusception is due to malignancy and a benign etiology remains elusive. The reported cases of benign causes include a lipoma and benign lymphadenopathy. We believe this to be the first such case report of a colonic diverticulum causing an intussusception. Despite an exploratory laparotomy of less than sixty minutes, the patient demised in the intensive care unit following an occipital lobe stroke. We believe this case of sigmoid intussusception with concomitant small intestinal diverticula to be the first such case report of its kind in English-language scientific publications.

Laparoscopic Tissue Repair of an Acutely Incarcerated Spigelian Hernia

Yagan Pillay,Rufaro Asefa 대한외상중환자외과학회 2021 Journal of Acute Care Surgery Vol.11 No.1

Spigelian hernias are a rare type of abdominal wall hernia. A weakness in the spigelian fascia causesabdominal contents to herniate between the abdominal muscle layers as an interparietal hernia. We present the case of a 72-year old woman with acute onset abdominal pain and distention. Acomputed tomography scan revealed an incarcerated spigelian hernia with small bowel obstruction. This necessitated an acute surgical intervention with a laparoscopic tissue repair. The case isunique as our patient had a large hernial neck measuring 4.8 centimeters, one of the largest inpublished literature. The laparoscopic tissue repair is outside the current norm for this type ofhernial repair and remains a rare type of surgical herniorrhaphy. Laparoscopic ventral hernia repairin the acute setting should form part of the surgical skill set of acute care surgeons as borne out bythe published literature and this case report.

Synergistic Utilization of Dichloroethylene as Sole Carbon Source by Bacterial Consortia Isolated from Contaminated Sites in Africa

Ademola O. Olaniran,Nokukhanya H. Mfumo,Dorsamy Pillay,Balakrishna Pillay 한국생물공학회 2006 Biotechnology and Bioprocess Engineering Vol.11 No.3

The widespread use and distribution of chloroethylene organic compounds is of serious concern owing to their carcinogenicity and toxicity to humans and wildlife. In an effort to develop active bacterial consortia that could be useful for bioremediation of chloroethylene-contaminated sites in Africa, 16 combinations of 5 dichloroethylene (DCE)-utilizing bacteria, isolated from South Africa and Nigeria, were assessed for their ability to degrade cis- and trans-DCEs as the sole carbon source. Three combinations of these isolates were able to remove up to 72% of the compounds within 7 days. Specific growth rate constants of the bacterial consortia ranged between 0.465 and 0.716 d-1, while the degradation rate constants ranged between 0.184 and 0.205 d-1, with 86.36~93.53 and 87.47~97.12% of the stoichiometric-expected chloride released during growth of the bacterial consortia in cis- and trans-DCE, respectively. Succession studies of the individual isolates present in the consortium revealed that the biodegradation process was initially dominated by Achromobacter xylosoxidans and subsequently by Acinetobacter sp. and Bacillus sp., respectively. The results of this study suggest that consortia of bacteria are more efficient than monocultures in the aerobic biodegradation of DCEs, degrading the compounds to levels that are up to 60% below the maximum allowable limits in drinking water.

Synergistic Utilization of Dichloroethylene as Sole Carbon Source by Bacterial Consortia Isolated from Contaminated Sites in Africa

Olaniran, Ademola O.,Mfumo, Nokukhanya H.,Pillay, Dorsamy,Pillay, Balakrishna The Korean Society for Biotechnology and Bioengine 2006 Biotechnology and Bioprocess Engineering Vol.11 No.3

The widespread use and distribution of chloroethylene organic compounds is of serious concern owing to their carcinogenicity and toxicity to humans and wildlife. In an effort to develop active bacterial consortia that could be useful for bioremediation of chloroethylene-contaminated sites in Africa, 16 combinations of 5 dichloroethylene (DCE)-utilizing bacteria, isolated from South Africa and Nigeria, were assessed for their ability to degrade cis- and trans- DCEs as the sole carbon source. Three combinations of these isolates were able to remove up to 72% of the compounds within 7 days. Specific growth rate constants of the bacterial consortia ranged between 0.465 and $0.716\;d^{-1}$ while the degradation rate constants ranged between 0.184 and $0.205\;d^{-1}$ with $86.36{\sim}93.53\;and\;87.47{\sim}97.12%$ of the stoichiometric-expected chloride released during growth of the bacterial consortia in cis- and trans-DCE, respectively. Succession studies of the individual isolates present in the consortium revealed that the biodegradation process was initially dominated by Achromobacter xylosoxidans and subsequently by Acinetobacter sp. and Bacillus sp., respectively. The results of this study suggest that consortia of bacteria are more efficient than monocultures in the aerobic biodegradation of DCEs, degrading the compounds to levels that are up to 60% below the maximum allowable limits in drinking water.