Search PubMed⌕ Search

Biomedical subjects

J Hendriks

Publications and source records attributed to J Hendriks.

At least 19 recordsLinked to original sources
PubMed2006

Cloning, sequencing and expression of white rhinoceros (Ceratotherium simum) interferon-gamma (IFN-gamma) and the production of rhinoceros IFN-gamma specific antibodies.

Bovine tuberculosis (BTB) is endemic in African buffalo (Syncerus caffer) in the Kruger National Park (KNP). In addition to buffalo, Mycobacterium bovis has been found in at least 14 other mammalian species in South Africa, including kudu (Tragelaphus strepsiceros), Chacma baboon (Papio ursinus) and lion (Panthera leo). This has raised concern about the spillover into other potentially susceptible species like rhinoceros, thus jeopardising breeding and relocation projects aiming at the conservation of biodiversity. Hence, procedures to screen for and diagnose BTB in black rhinoceros (Diceros bicornis) and white rhinoceros (Ceratotherium simum) need to be in place. The Interferon-gamma (IFN-gamma) assay is used as a routine diagnostic tool to determine infection of cattle and recently African buffalo, with M. bovis and other mycobacteria. The aim of the present work was to develop reagents to set up a rhinoceros IFN-gamma (RhIFN-gamma) assay. The white rhinoceros IFN-gamma gene was cloned, sequenced and expressed as a mature protein. Amino acid (aa) sequence analysis revealed that RhIFN-gamma shares a homology of 90% with equine IFN-gamma. Monoclonal antibodies, as well as polyclonal chicken antibodies (Yolk Immunoglobulin-IgY) with specificity for recombinant RhIFN-gamma were produced. Using the monoclonals as capture antibodies and the polyclonal IgY for detection, it was shown that recombinant as well as native white rhinoceros IFN-gamma was recognised. This preliminary IFN-gamma enzyme-linked immunosorbent assay (ELISA), has the potential to be developed into a diagnostic assay for M. bovis infection in rhinoceros.

Amino Acid Sequence↗
PubMed2006

Superior sulcus tumor arising in an azygos lobe.

A non-small cell lung cancer presenting as a superior sulcus tumor in an azygos lobe has not yet been reported. We present such a case in a 69-year-old man undergoing complete resection after induction chemoradiotherapy and discuss the specific location of a superior sulcus tumor and the aberrant anatomy of an azygos lobe.

Aged↗
PubMed2006

Development of a matrix to evaluate the threat of biological agents used for bioterrorism.

Adequate public health preparedness for bioterrorism includes the elaboration of an agreed list of biological and chemical agents that might be used in an attack or as threats of deliberate release. In the absence of counterterrorism intelligence information, public health authorities can also base their preparedness on the agents for which the national health structures would be most vulnerable. This article aims to describe a logical method and the characteristics of the variables to be brought in a weighing process to reach a priority list for preparedness. The European Union, in the aftermath of the anthrax events of October 2001 in the United States, set up a task force of experts from multiple member states to elaborate and implement a health security programme. One of the first tasks of this task force was to come up with a list of priority threats. The model, presented here, allows Web-based updates for newly identified agents and for the changes occurring in preventive measures for agents already listed. The same model also allows the identification of priority protection action areas.

Bioterrorism↗
PubMed2005

Heparan sulfate proteoglycan binding promotes APRIL-induced tumor cell proliferation.

APRIL, a proliferation-inducing ligand, is a member of the tumor necrosis factor (TNF) family that is expressed by various types of tumors and influences their growth in vitro and in vivo. Two receptors, transmembrane activator and cyclophilin ligand interactor (TACI) and B-cell maturation antigen (BCMA), bind APRIL, but neither is essential for the tumor-promoting effects, suggesting that a third receptor exists. Here, we report that APRIL specifically binds to heparan sulfate proteoglycans (HSPG) on the surface of tumor cells. This binding is mediated by the heparin sulfate side chains and can be inhibited by heparin. Importantly, BCMA and HSPG do not compete, but can bind APRIL simultaneously, suggesting that different regions in APRIL are critical for either interaction. In agreement, mutation of three lysines in a putative heparin sulfate-binding motif, which is not part of the TNF fold, destroys interaction with HSPG, while binding to BCMA is unaffected. Finally, whereas interaction of APRIL with HSPG does not influence APRIL-induced proliferation of T cells, it is crucial for its tumor growth-promoting activities. We therefore conclude that either HSPG serve as a receptor for APRIL or that HSPG binding allows APRIL to interact with a receptor that promotes tumor growth.

Amino Acid Sequence↗
PubMed2005

Video-assisted thoracic surgery (VATS) for primary spontaneous pneumothorax: how I do it ?

The precise management of primary spontaneous pneumothorax remains controversial due to the lack of large prospective randomized trials. This not only regards the indications for conservative or invasive treatment but also the precise technique for air evacuation and recurrence prevention. The technique of video-assisted thoracic surgery is described as it is performed in our centre for the treatment of primary spontaneous pneumothorax.

Humans↗
PubMed2004

Bichat guidelines for the clinical management of smallpox and bioterrorism-related smallpox.

Smallpox is a viral infection caused by the variola virus. It was declared eradicated worldwide by the Word Health Organization in 1980 following a smallpox eradication campaign. Smallpox is seen as one of the viruses most likely to be used as a biological weapon. The variola virus exists legitimately in only two laboratories in the world. Any new case of smallpox would have to be the result of human accidental or deliberate release. The aerosol infectivity, high mortality, and stability of the variola virus make it a potential and dangerous threat in biological warfare. Early detection and diagnosis are important to limit the spread of the disease. Patients with smallpox must be isolated and managed, if possible, in a negative-pressure room until death or until all scabs have been shed. There is no established antiviral treatment for smallpox. The most effective prevention is vaccination before exposure.

Bioterrorism↗
PubMed2004

Prognostic value of nonangiogenic and angiogenic growth patterns in non-small-cell lung cancer.

An essential prerequisite of nonangiogenic growth appears to be the ability of the tumour to preserve the parenchymal structures of the host tissue. This morphological feature is visible on a routine tissue section. Based on this feature, we classified haematoxylin and eosin-stained tissue sections from 279 patients with non-small-cell lung cancer into three growth patterns: destructive (angiogenic; n=196), papillary (intermediate; n=38) and alveolar (nonangiogenic; n=45). A Cox multiple regression model was used to test the prognostic value of growth patterns together with other relevant clinicopathological factors. For overall survival, growth pattern (P=0.007), N-status (P=0.001), age (P=0.020) and type of operation (P=0.056) were independent prognostic factors. For disease-free survival, only growth pattern (P=0.007) and N-status (P<0.001) had an independent prognostic value. Alveolar (hazard ratio=1.825, 95% confidence interval=1.117-2.980, P=0.016) and papillary (hazard ratio=1.977, 95% confidence interval=1.169-3.345, P=0.011) growth patterns were independent predictors of poor prognosis. The proposed classification has an independent prognostic value for overall survival as well as for disease-free survival, providing a possible explanation for survival differences of patients in the same disease stage.

Adult↗
PubMed2004

Juvenile sexual delinquents: contrasting child abusers with peer abusers.

BACKGROUND: There is growing concern regarding juvenile sex offenders, and concomitant interest in a more scientific database which could help direct management and treatment resources. AIMS: To investigate whether juveniles who sexually offend against children (or those at least five years younger than themselves) differ from those who sexually assault their peers or older victims. METHOD: The study is based on data from psychological screenings conducted for the juvenile courts in the Netherlands. RESULTS: As hypothesized, juvenile child molesters scored higher on neuroticism, had experienced more social problems, and had been bullied more often at school than their peers who sexually assaulted same-age or older victims. Child molesters also reported a more negative self-image. When referred for screening, they were younger but had committed more sex offences, more often against males than females. CONCLUSIONS: The results were suggestive of greater need for psychological interventions in the child molester group, although in both groups substantial minorities had had experience of early childhood deprivation or abuse.

Adolescent↗
PubMed2004

Aortic graft infection from appendicitis. A case report.

Fifteen years after aortobifemoral bypass and five years after left femoropopliteal bypass, a 73-year old man presented with a vague abdominal pain syndrome. After an extensive work-up, aortobifemoral graft infection was suspected; an appendiceal abscess infiltrating the prosthesis was discovered during exploratory laparotomy. Appendectomy was performed followed by removal of the vascular graft, the latter being replaced by a bilateral axillofemoral prosthesis. Aortic graft infection from appendicitis is an extremely rare condition; a review of similar cases is presented.

Abdominal Pain↗
PubMed2003

Current Internet use and preferences of IVF and ICSI patients.

BACKGROUND: Nowadays, the Internet has a tremendous impact on modern society, including healthcare practice. The study aim was to characterize current Internet use by IVF and ICSI patients and to identify their preferences regarding Internet applications in fertility care. METHODS: A total of 163 couples with fertility problems awaiting an IVF or ICSI procedure in the University Medical Centre Nijmegen, The Netherlands, was asked to complete a written questionnaire on Internet use in general, and also for fertility-related problems, preferences regarding Internet applications in fertility care and demographic characteristics. RESULTS: The response rate was 82%. In total, 81% of infertile couples used the Internet. Multivariate logistic regression analysis showed ethnic background and annual family income to be significant predictors of Internet use. Some 66% of Internet users and 54% of the total study population used the Internet for fertility-related problems. The female partners were the main Internet users with regard to fertility-related issues. In terms of preferences of the study participants, the majority favoured personal medical information online. CONCLUSIONS: Most infertile couples used the Internet with respect to fertility-related problems and were interested in implementation of Internet applications in fertility care. Healthcare providers should actively participate in the development and implementation of Internet applications in fertility care.

Adult↗
PubMed2002

Urinothorax: a rare pleural effusion.

A 68-year old man suffered severe respiratory distress, secondary to massive pleural effusion on the right side several hours after removing the nephrostomy tube from both right and left kidneys. A chest tube was placed and a yellowish fluid was evacuated. This was found to be urine from a fistula between the right pelvis and the chest cavity. Diagnosis and management of urinothorax are discussed.

Aged↗
PubMed2002

Long-term results after video-assisted thoracic surgery for spontaneous pneumothorax.

OBJECTIVE: Analysis of the long-term results of video-assisted thoracic surgery (VATS) for spontaneous pneumothorax in patients treated in two surgical centres from May 1994 until December 2000. METHODS: A cohort of 86 patients was studied retrospectively. For final analysis, 74 patients undergoing 76 VATS procedures were included. RESULTS: Sixty-three procedures for primary spontaneous pneumothorax (PSP) and 13 procedures for secondary spontaneous pneumothorax (SSP) were performed. In 78.9% (n = 60) blebs or bullae were resected with an endostapler device. In 2.6% (n = 2) an apical fibrotic zone was resected. In 71.1% (n = 54) a subtotal pleurectomy was performed combined with an abrasion in 41 cases. In 21.1% (n = 16) a total pleurectomy and in 7.8% (n = 6) an abrasion was performed. Operative mortality was 1.3% (n = 1) and total operative morbidity 25.4% in the PSP group and 76.9% in the SSP group. Mean follow-up was 36 months. The global recurrence rate was 5.3% (n = 4), being 4.8% (n = 3) in the PSP group and 7.7% (n = 1) in the SSP group. Recurrences occurred at 1 (n = 2), 2 (n = 1) and 16 (n = 1) months after the initial operation. The incidence of postoperative neuralgia was 17.1% (n = 13). One patient needed analgesics for the neuralgia. CONCLUSION: VATS treatment of spontaneous pneumothorax proves to be effective. In cases of SSP, VATS treatment is feasible but a higher morbidity rate should be anticipated.

Adult↗
PubMed2001

Formation of a new buried charge drives a large-amplitude protein quake in photoreceptor activation.

Photoactive yellow protein (PYP) is a eubacterial photoreceptor and a structural prototype of the PAS domain superfamily of receptor and regulatory proteins. We investigate the activation mechanism of PYP using time-resolved Fourier transform infrared (FTIR) spectroscopy. Our data provide structural, kinetic, and energetic evidence that the putative signaling state of PYP is formed during a large-amplitude protein quake that is driven by the formation of a new buried charge, COO(-) of the conserved Glu46, in a highly hydrophobic pocket at the active site. A protein quake is a process consisting of global conformational changes that are triggered and driven by a local structural "fault". We show that large, global structural changes take place after Glu46 ionization via intramolecular proton transfer to the anionic p-coumarate chromophore, and are suppressed by the absence of COO(-) formation in the E46Q mutant. Our results demonstrate the significance of buried charge formation in photoreceptor activation. This mechanism may serve as one of the general themes in activation of a range of receptor proteins. In addition, we report the results of time-resolved FTIR spectroscopy of PYP crystals. The direct comparison of time-resolved FTIR spectroscopic data of PYP in aqueous solution and in crystals reveals that the structure of the putative signaling state is not developed in P6(3) crystals. Therefore, when the structural developments during the functional process of a protein are experimentally determined to be very different in crystals and solutions, one must be cautious in drawing conclusions regarding the functional mechanism of proteins based on time-resolved X-ray crystallography.

Bacterial Proteins↗
PubMed2001

Constitutive CD27/CD70 interaction induces expansion of effector-type T cells and results in IFNgamma-mediated B cell depletion.

The interaction between the TNF receptor family member CD27 and its ligand CD70 provides a costimulatory signal for T cell expansion. Normally, tightly regulated expression of CD70 ensures the transient availability of this costimulatory signal. Mice expressing constitutive CD70 on B cells had higher peripheral T cell numbers that showed increased differentiation toward effector-type T cells. B cell numbers in CD70 transgenic (TG) mice progressively decreased in primary and secondary lymphoid organs. This B cell depletion was caused by CD27-induced production of IFNgamma in T cells. We conclude that apart from its role in controlling the size of the activated T cell pool, CD27 ligation contributes to immunity by facilitating effector T cell differentiation.

Animals↗
PubMed2000

Isolation, reconstitution and functional characterisation of the Rhodobacter sphaeroides photoactive yellow protein.

We report the isolation, functional reconstitution and photophysical characterisation of Rhodobacter sphaeroides photoactive yellow protein (PYP), of which the gene was recently cloned. Reconstitution of the his-tagged purified apo-protein with 4-hydroxy-cinnamic acid yields the characteristic blue absorbance at 446 nm, but surprisingly also an absorbance peak at 360 nm. This additional peak is not caused by binding of a second chromophore, as confirmed with mass spectroscopy. Moreover, reconstitution with the 'locked' analogue 7-hydroxy-coumarin-3-carboxylic acid yields only a single absorbance peak at 441 nm. The 446 nm and 360 nm species are part of a temperature- and pH-dependent equilibrium. Photoactivation of the protein leads to formation of a blue-shifted intermediate as in other PYPs, with a 100-fold increased groundstate recovery rate (k(pB-->pG)=500 s(-1)) compared to E-PYP.

Apoproteins↗
PubMed2000

Probing the nature of the blue-shifted intermediate of photoactive yellow protein in solution by NMR: hydrogen-deuterium exchange data and pH studies.

The nature of the pB intermediate of photoactive yellow protein (PYP) from Ectothiorhodospira halophila has been probed by NMR. pH-dependent changes in the NMR spectrum of the dark state of PYP are shown to closely mimic exchange broadening effects observed previously in the NMR spectrum of the pB intermediate in solution. Amide H-D exchange data show that while pB retains a solid protected core, two regions become significantly less protected than the dark state. The amide exchange data help to rationalize why the conformational exchange process affects the N-terminal 28-residue segment of the protein, which is not close to the site of chromophore rearrangement. At very low pH (pH 1.7), the dark state NMR spectrum displays approximately 30 very sharp signals, which are characteristic of a portion of the molecule becoming unfolded. Similarities between the dark state spectra at pH approximately 3.2 and the spectra of pB suggest a model for pB in solution where the protein exists in an equilibrium between a well-ordered state and a state in which a region is unfolded. Such a two-state model accounts for the exchange phenomena observed in the NMR spectra of pB, and the hydrophobic exposure and lability inferred from thermodynamic data. It is likely that in the crystalline environment the ordered form of pB is strongly favored.

Amides↗
PubMed2000

Nitric oxide reductases in bacteria.

Nitric oxide reductases (NORs) that are found in bacteria belong to the large enzyme family which includes cytochrome oxidases. Two types of bacterial NORs have been characterised. One is a cytochrome bc-type complex (cNOR) that receives electrons from soluble redox protein donors, whereas the other type (qNOR) lacks the cytochrome c component and uses quinol as the electron donor. The latter enzyme is present in several pathogens that are not denitrifiers. We summarise the current knowledge on bacterial NORs, and discuss the evolutionary relationship between them and cytochrome oxidases in this review.

Amino Acid Sequence↗