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K H Lam

Publications and source records attributed to K H Lam.

At least 19 recordsLinked to original sources
PubMed2006

TuBaFrost 3: regulatory and ethical issues on the exchange of residual tissue for research across Europe.

The regulatory regimes for research with residual tissue and accompanying data differ widely between countries in the European Union (EU): from specific consent to opt-out or even no consent at all. This could greatly hamper research where the exchange of tissue and accompanying data has become the gold standard, like in TubaFrost. Instead of adhering to international guidelines, which have a democratic deficit, or an attempt for a new set of possible harmonising rules, TubaFrost chose to create a coordinating rule: if tissue may legitimately be used for a certain kind of research in the country where it was taken and under whose jurisdiction the patient falls, it may also be used for such research in the country where it is sent to in the context of a scientific program even if in that other country other regulations would apply for research with residual tissue taken from patients under their jurisdiction. This coordinating rule has a sound basis in EU law in general and will solve the problems related to diverging national regulatory regimes in the case of cross national research with residual tissue.

Ethics, Research↗
PubMed2006

TuBaFrost 5: multifunctional central database application for a European tumor bank.

Developing a tissue bank database has become more than just logically arranging data in tables combined with a search engine. Current demand for high quality samples and data, and the ever-changing legal and ethical regulations mean that the application must reflect TuBaFrost rules and protocols for the collection, exchange and use of tissue. To ensure continuation and extension of the TuBaFrost European tissue bank, the custodianship of the samples, and hence the decision over whether to issue samples to requestors, remains with the local collecting centre. The database application described in this article has been developed to facilitate this open structure virtual tissue bank model serving a large group. It encompasses many key tasks, without the requirement for personnel, hence minimising operational costs. The Internet-accessible database application enables search, selection and request submission for requestors, whereas collectors can upload and edit their collection. Communication between requestor and involved collectors is started with automatically generated e-mails.

Computer Simulation↗
PubMed2006

TuBaFrost 2: Standardising tissue collection and quality control procedures for a European virtual frozen tissue bank network.

Tumour Bank Networking presents a great challenge for oncological research as in order to carry out large-scale, multi-centre studies with minimal intrinsic bias, each tumour bank in the network must have some fundamental similarities and be using the same standardised and validated procedures. The European Human Frozen Tumour Tissue Bank (TuBaFrost) has responded to this need by the promotion of an integrated platform of tumour banks in Europe. The operational framework for TuBaFrost has drawn upon the best practice of standard workflows and operating procedures employed by members of the TuBaFrost project and key initiatives worldwide.

Biological Specimen Banks↗
PubMed2006

TuBaFrost 4: access rules and incentives for a European tumour bank.

When designing infrastructure for a networked virtual tumour bank (samples remain at the collector institutes and sample data are collected in a searchable central database), it is apparent that this can only function properly after developing an adequate set of rules for use and access. These rules must include sufficient incentives for the tissue sample collectors to remain active within the network and maintain sufficient sample levels in the local bank. These requirements resulted in a key TuBaFrost rule, stating that the custodianship of the samples remains under the authority of the local collector. As a consequence, the samples and the decision to issue the samples to a requestor are not transferred to a large organisation but instead remain with the collector, thus allowing autonomous negotiation between collector and requestor, potential co-authorship in publications or compensation for collection and processing costs. Furthermore, it realises a streamlined cost effective network, ensuring tissue visibility and accessibility thereby improving the availability of large amounts of samples of highly specific or rare tumour types as well as providing contact opportunities for collaboration between scientists with cutting edge technology and tissue collectors. With this general purpose in mind, the rules and responsibilities for collectors, requestors and central office were generated.

Europe↗
PubMed2006

TuBaFrost 1: Uniting local frozen tumour banks into a European network: an overview.

TuBaFrost is the consortium responsible for the creation of a virtual European human frozen tumour tissue bank: a collection of high quality frozen residual, accurately classified tumour tissue samples, which are stored in European cancer centres and universities. This virtual tissue bank, searchable on the internet, has rules for access and use, and a code of conduct to comply with the various legal and ethical regulations in European countries. The easy accessibility and the European scale of the bank will result in the availability of a large number of samples even of rarer tumour types. Standardisation of collection, storage and quality control throughout the network is achieved minimising inter-institutional variability. A website providing access to upload, search and request samples is a key tool of the tissue bank. The search engine makes use of virtual microscopy. An overview of the development of the European virtual frozen tissue bank infrastructure is described in this paper. The various key aspects are described in more detail in a series of articles to appear in this Journal.

Biological Specimen Banks↗
PubMed2006

TuBaFrost 6: virtual microscopy in virtual tumour banking.

Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated Virtual Microscope systems can be acquired, with the capability to quickly scan large batches of glass slides at high magnification and compress and store the large images on disc, which subsequently can be consulted through the Internet. The images are stored on an image server, which can give simple, easy to transfer pictures to the user specifying a certain magnification on any position in the scan. This offers new opportunities in histology review, overcoming the necessity of the dynamic telepathology systems to have compatible software systems and microscopes and in addition, an adequate connection of sufficient bandwidth. Consulting the images now only requires an Internet connection and a computer with a high quality monitor. A system of complete pathology review supporting bio-repositories is described, based on the implementation of this technique in the European Human Frozen Tumor Tissue Bank (TuBaFrost).

Computer Simulation↗
PubMed2006

TuBaFrost: European virtual tumor tissue banking.

TuBaFrost is a consortium responsible for the task to create a virtual European human frozen tumor tissue bank, composed of high quality frozen tumor tissue collections with corresponding accurate diagnosis stored in European cancer centers and universities, searchable on the Internet, providing rules for access and use and a code of conduct to comply with the various legal and ethical regulations in European countries. Such infrastructure would enlarge tissue availability and accessibility in large amounts of specified or even rare tumor samples. Design of an infrastructure for European residual tissue banking with the described characteristics, clear focus points emerge that can be broken down in dedicated subjects: (1) standardization and quality assurance (QA) to avoid inter-institute quality variation; (2) law and ethics enabling exchange of tissue samples possible between institutes in the different European countries, where law and ethics are characterized by a strong variability; (3) rules for access, with sufficient incentives for collectors; (4) central database application containing innovations on search and selection procedures; (5) support when needed with histology images; and (6) Internet access to search and upload, with in addition a solid website giving proper information on the procedures, intentions and activities not only to the scientific community, but also to the general public. One consortium decision, part of the incentives for collectors, had major impact on the infrastructure; custodianship over the tissues as well as the tissues stay with the collector institute. Resulting in specimens that are not given to an organization, taking decisions on participation of requests, but instead the local collected tissues stay very easy to access by the collector and allows autonomous negotiation between collector and requestor on cooperation, coauthorship in publication or compensation in costs. Thereby, improving availability of large amounts of high quality samples of a highly specified or rare tumor types and contact opportunities for cooperation with other institutes.

Databases, Factual↗
PubMed2006

Virtual microscopy in virtual tumor banking.

Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated virtual microscope systems can be acquired, with the capability to quickly scan large batches of glass slides at high magnification and compress and store the large images on disc, which subsequently can be consulted through the Internet. The images are stored on an image server, which can give simple, easy to transfer pictures to the user specifying a certain magnification on any position in the scan. This offers new opportunities in histology review, overcoming the necessity of the dynamic telepathology systems to have compatible software systems and microscopes and in addition, an adequate connection of sufficient bandwidth. Consulting the images now only requires an Internet connection and a computer with a high quality monitor. A system of complete pathology review supporting biorepositories is described, based on the implementation of this technique in the European Human Frozen Tumor Tissue Bank (TuBaFrost).

Databases, Factual↗
PubMed2003

Isolated ventricular non-compaction presenting with ventricular tachycardia.

Isolated ventricular non-compaction is a rare congenital cardiomyopathy, manifested morphologically as prominent myocardial trabeculations and deep inter-trabecular recesses that communicate with the ventricular cavity. Heart failure is the most common presenting condition. Other manifestations include arrhythmia and cardioembolic events. This report is illustrative of isolated ventricular non-compaction in a 78-year-old woman. The diagnosis was made when she presented with ventricular tachycardia many years after a stroke. She subsequently underwent implantation of a cardioverter-defibrillator. This report documents an uncommon presentation of this disease entity in the oldest patient at presentation as yet reported in the literature.

Aged↗
PubMed2002

[Pulmonary problems associated with lymphoplasmacytic lymphoma (Waldenström's macroglobulinemia)].

A 62-year-old man, known for some years due to lymphoplasmacytic lymphoma, was admitted with progressive dyspnoea. Multiple lung infiltrates were found upon X-ray examination. Because of the suspicion of an infection, a bronchoscopy with bronchoalveolar lavage was performed. No infectious cause could be established. Upon cytological examination, a highly increased level of kappa-positive B-lymphoid cells was found, as is seen in cases of lymphoplasmacytic lymphoma (Waldenström's macroglobulinaemia). Following chemotherapy, the dyspnoea lessened and the pulmonary infiltrates disappeared. In patients with a lymphoproliferative disorder, pulmonary infiltrates due to infection are found relatively frequently. This case report highlights a rare complication of the disease, namely pulmonary infiltrates caused by infiltration of lymphoplasmacytic cells, emphasising the importance of cytological examination of broncho-alveolar lavage fluid.

Bronchoalveolar Lavage Fluid↗
PubMed2000

Surgical treatment of recalcitrant radiation-induced gastric erosions.

BACKGROUND: Uncontrolled bleeding as a result of radiation gastritis in patients who have pharyngo-laryngo-esophagectomy and gastric pull-up is seldom reported. Surgical resection in the management of this condition has rarely been described. METHOD: A 66-year-old man with hypopharyngeal cancer was treated by pharyngo-laryngo-esophagectomy and gastric transposition. He received postoperative radiotherapy and had recurrent hemorrhagic gastritis, necessitating surgical resection. The manubrium was resected to access the mediastinal part of the gastric conduit. The diseased part of the gastric conduit was removed and a free jejunal graft was interposed to replace the resected stomach. RESULTS: Manubrial resection offered adequate access to the stomach transposed in the mediastinum, and the life-threatening bleeding gastritis was successfully controlled by surgical resection. CONCLUSION: Surgical resection of the radiation-damaged transposed stomach through a manubrial resection approach can safely be performed. Free jejunal graft is the choice of reconstruction of the circumferential defect.

Aged↗
PubMed2000

Synthesis of a new chiral ligand, 6, 6'-dihydroxy-5, 5'-biquinoline (BIQOL) and its applications in the asymmetric addition of diethylzinc to aldehydes.

A new chiral ligand 6, 6'-dihydroxy-5, 5'-biquinoline (BIQOL, 2) was prepared via Cu2+ mediated coupling. The resolution was carried out by separating the corresponding ditrifluomethanesulfonate on chiral column. When applied to the enantioselective addition of diethylzinc to aromatic aldehydes, this ligand induced the reaction with enantioselectivity equivalent to that induced by BINOL. The effects of solvent and reaction temperature on enantioselectivity were also studied.

Journal Article↗
PubMed2000

Transradial coronary angioplasty and stenting--immediate results and 3-month clinical follow-up in the first 50 patients performed at the National Heart Institute.

AIM: To explore the safety and feasibility of coronary angioplasty and stenting via the radial artery in a heterogenous group of patients and to report the immediate and 3-month clinical follow-up. BACKGROUND: The use of the transradial approach for coronary angiography was first described by Lucien Campeau in 1989. Based on the favourable initial results, this technique has gained widespread acceptance worldwide. Ferdinand Kiemeneij's work in transradial angioplasty and stenting has taken invasive cardiology into the exciting new era of "minimally invasive coronary intervention". METHODS AND RESULTS: Fifty consecutive patients underwent Transradial Percutaneous Transluminal Coronary Angioplasty (PTCA) with or without stenting from mid March 98-December 98. The right radial approach was utilised in 41 patients (80%) while the left in 9 patients. Ninety percent of the procedures was done on an adhoc basis. Diabetes mellitus was present in 38% of patients. Eighty percent of patients had unstable angina pectoris and 60% had a prior history of acute myocardial infarction. The commonest vessel involved was the LAD (51%) and type B lesions predominated (54%). PTCA was successful in 96%. One patient had a total LAD occlusion, which could not be wired, and another developed severe spasm during catheter manipulation. The latter had successful PTCA via the right femoral route Stents were utilised in 57% of patients. The commonest indication for stenting was suboptimal PTCA results (89%) and dissection (14%). There was no stent embolisation and all stents were successfully deployed (100%). One patient developed acute stent thrombosis necessitating repeat PTCA and another patient sustained an acute anteroseptal myocardial infarction 5 days post procedure as a result of subacute stent thrombosis and died. Two patients had successful primary PTCA. There was no bleeding or vascular complications. 60% of patients were treated on an outpatient basis. At 3-months follow up, 1 patient required CABG's for disease progression. Three patients had absent radial pulses without adverse consequence. No patient required repeat PTCA at follow up. CONCLUSION: In summary, adhoc PTCA and stenting is safe and feasible in our patient population. A study on the cost effectiveness of the procedure compared to conventional femoral PTCA is warranted.

Angioplasty, Balloon, Coronary↗
PubMed1999

A comparative investigation on the biosorption of lead by filamentous fungal biomass.

The removal of lead from aqueous solutions by adsorption on filamentous fungal biomass was studied. Batch biosorption experiments were performed to screen a series of selected fungal strains for effective lead removal at different metal and biomass concentrations. Biosorption of the Pb2+ ions was strongly affected by pH. The fungal biomass exhibited the highest lead adsorption capacity at pH 6. Isotherms for the biosorption of lead on fungal biomass were developed and the equilibrium data fitted well to the Langmuir isotherm model. At pH 6, the maximum lead biosorption capacity of Mucor rouxii estimated with the Langmuir model was 769 mg/g dry biomass, significantly higher than that of most microorganisms. Biomass of Mucor rouxii showed specific selectivity for Pb2+ over other metals ions such as Zn2+, Ni2+ and Cu2+. This fungal strain may be applied to develop potentially cost-effective biosorbent for removing lead from effluents. The technique of scanning electron microscopy coupled with X-ray dispersion analysis shows that Pb2+ has exchanged with K+ and Ca2+ on the cell wall of Mucor rouxii, thereby suggesting ion exchange as one of the dominant mechanisms of metal biosorption for this fungal strain.

Absorption↗
PubMed1999

The role of neck dissection in head and neck mucosal squamous cancer.

The most clinically useful system of classification of neck lymph nodes is grouping into levels I-V. Anatomical, clinical and pathological studies demonstrate that although generally lymphatic flow is from above downwards, level I is often bypassed and level V is seldom involved. Neck dissection is classified into radical, modified radical, selective and extended radical neck dissections. Recent studies demonstrate that elective neck dissection is beneficial to the outcome of oral cancer patients, but not necessarily to laryngeal and pharyngeal cancer patients. Modified radical neck dissection is as effective as radical neck dissection when performed in the elective situation. Selective neck dissection in the form of supra-omohyoid neck dissection is useful as a staging procedure. Modified radical neck dissection is acceptable for the N1 neck provided postoperative radiotherapy is given.

Carcinoma, Squamous Cell↗
PubMed1998

Construction of an efficient Bacillus subtilis system for extracellular production of heterologous proteins.

An efficient expression/secretion vector, designated pM2Veg, was constructed for extracellular production of heterologous proteins in Bacillus subtilis. To construct pM2Veg, a synthetic cassette, the Veg cassette carrying: (1) the strong vegetative vegI promoter from B. subtilis, (2) the Escherichia coli lac operator, (3) the B. subtilis consensus ribosome-binding site, (4) the Staphylococcal protein A leader sequence, (5) a cloning region for insertion of foreign genes, (6) translational stop codons in all three reading frames, and (7) the gnt transcriptional terminator, was cloned into a derivative of the stable pRB373 B. subtilis/E. coli shuttle plasmid, the pM2 vector. The application of pM2Veg to effect secretory production of heterologous proteins was illustrated using two widely different proteins: the endoglucanase (Eng) encoded by the cenA gene of Cellulomonas fimi and human epidermal growth factor (hEGF). Levels of Eng and hEGF measured in culture supernatant samples of B. subtilis transformants harboring recombinant constructs formed between pM2Veg and the cenA and hEGF genes were 8.3 U ml-1 and 7.0 mg l-1, respectively. The Eng activity is more than four times higher than the yield from the best cenA recombinant construct previously reported, and the hEGF data represents the first successful expression of the factor in B. subtilis.

3T3 Cells↗
PubMed1997

Submucosal tumor extension in hypopharyngeal cancer.

OBJECTIVES: To study the incidence and extent of submucosal tumor extension in hypopharyngeal cancer and to evaluate the impact on the tumor recurrence and overall survival rates. METHODS: Fifty-seven resected specimens of hypopharyngeal cancer were studied in detail from January 1986 to December 1989 by use of the whole-organ, step-serial sectioning technique. RESULTS: Three types of submucosal tumor extension could be identified. Type I extension was characterized by a tumor with a smooth round contour that extended submucosally. The mucosa was thereby elevated and was detectable on gross inspection at operation. In type II extension, tongues and islands of tumor infiltrated within the submucosa, and these were not noticeable on gross examination. Skip metastasis in the submucosa where the submucosal tumor was completely separated from the main tumor bulk was classified as type III extension. Thirty-three patients (58%) had submucosal tumor extension. The frequencies (and extents of submucosal tumor extension) in the superior, medial, lateral, and inferior directions were 16% (3-10 mm), 37% (2-37 mm), 26% (2-37 mm), and 28% (3-35 mm), respectively. Two thirds of the submucosal extension was type I (22 of 33), and only 1 patient had a true skip lesion submucosally (type III extension). Type II submucosal extension was found in one third of the patients (11 of 33). This occurred significantly more often in the patients who had received radiotherapy before surgery (82% [9/11]; P < .001; 95% confidence interval, 1.28-4.44). The presence of submucosal tumor extension had no effect on the tumor recurrence and overall survival rates. CONCLUSIONS: The incidence of submucosal tumor extensions in hypopharyngeal cancer is high (58%), but most (67%) of them can be detected grossly at operation. The presence of submucosal tumor extension does not adversely affect the survival and tumor recurrence rates.

Adult↗