Attenuation of 7-ketocholesterol- and 7ß-hydroxycholesterol-induced oxiapoptophagy by nutrients, synthetic molecules and oils: Potential for the prevention of age-related diseases.

Age-related diseases for which there are no effective treatments include cardiovascular diseases; neurodegenerative diseases such as Alzheimer's disease; eye disorders such as cataract and age-related macular degeneration; and, more recently, Severe Acute Respiratory Syndrome (SARS-CoV-2). These diseases are associated with plasma and/or tissue increases in cholesterol derivatives mainly formed by auto-oxidation: 7-ketocholesterol, also known as 7-oxo-cholesterol, and 7ß-hydroxycholesterol. The formation of these oxysterols can be considered as a consequence of mitochondrial and peroxisomal dysfunction, leading to increased in oxidative stress, which is accentuated with age. 7-ketocholesterol and 7ß-hydroxycholesterol cause a specific form of cytotoxic activity defined as oxiapoptophagy, including oxidative stress and induction of death by apoptosis associated with autophagic criteria. Oxiaptophagy is associated with organelle dysfunction and in particular with mitochondrial and peroxisomal alterations involved in the induction of cell death and in the rupture of redox balance. As the criteria characterizing 7-ketocholesterol- and 7ß-hydroxycholesterol-induced cytotoxicity are often simultaneously observed in major age-related diseases (cardiovascular diseases, age-related macular degeneration, Alzheimer's disease) the involvement of these oxysterols in the pathophysiology of the latter seems increasingly likely. It is therefore important to better understand the signalling pathways associated with the toxicity of 7-ketocholesterol and 7ß-hydroxycholesterol in order to identify pharmacological targets, nutrients and synthetic molecules attenuating or inhibiting the cytotoxic activities of these oxysterols. Numerous natural cytoprotective compounds have been identified: vitamins, fatty acids, polyphenols, terpenes, vegetal pigments, antioxidants, mixtures of compounds (oils, plant extracts) and bacterial enzymes. However, few synthetic molecules are able to prevent 7-ketocholesterol- and/or 7ß-hydroxycholesterol-induced cytotoxicity: dimethyl fumarate, monomethyl fumarate, the tyrosine kinase inhibitor AG126, memantine, simvastatine, Trolox, dimethylsufoxide, mangafodipir and mitochondrial permeability transition pore (MPTP) inhibitors. The effectiveness of these compounds, several of which are already in use in humans, makes it possible to consider using them for the treatment of certain age-related diseases associated with increased plasma and/or tissue levels of 7-ketocholesterol and/or 7ß-hydroxycholesterol.

Nocardiosis in freshwater reared Chinook salmon (Oncorhynchus tshawytscha).

CASE HISTORY: An investigation was conducted to identify the cause of mortalities in freshwater reared Chinook salmon (Oncorhynchus tshawytscha). Mortalities occurred in juvenile salmon, at a salmon rearing facility in the South Island of New Zealand. The affected fish were from a pen inside the facility with no surrounding pens or other year classes affected. CLINICAL FINDINGS: Clinically affected fish presented with skin lesions. The majority of skin lesions were unruptured, boil-like, raised circular masses up to 4 cm in diameter, particularly on the dorsolateral aspects and the flank. A number of fish presented with large ulcers resulting from rupturing of the raised lesions described above. This clinical presentation showed similarities to that of furunculosis caused by typical Aeromonas salmonicida, a bacterium exotic to New Zealand. LABORATORY FINDINGS: Samples were taken from two representative fish in the field for histopathology, bacterial culture and molecular testing. Histopathological findings included granulomatous lesions in the kidney, liver, spleen and muscle. When stained with Fite-Faraco modified acid fast stain filamentous branching rods were identified within these granulomas. Following bacterial culture of kidney swabs pure growth of small white matt adherent colonies was observed. This isolate was identified as a Nocardia species by biochemical testing and nucleotide sequencing of the partial 16S rRNA gene. All samples were negative for A. salmonicida based on bacterial culture and PCR testing. DIAGNOSIS: Nocardiosis caused by a Nocardia species. CLINICAL RELEVANCE: Nocardiosis in these fish was caused by a previously undescribed Nocardia species that differs from the species known to be pathogenic to fish: N. asteroides, N. salmonicida and N. seriole. This bacterium is likely to be a new or unnamed environmental species of Nocardia that has the potential to cause disease in Chinook salmon under certain conditions. The clinical presentation of this Nocardia species manifested as raised, boil-like skin lesions which has similarities to the presentation of furunculosis caused by the bacterium typical A. salmonicida, a species exotic to New Zealand.

Bevacizumab combined with gemcitabine and capecitabine for advanced pancreatic cancer: a phase II study.

A total of 50 patients with advanced pancreatic cancer were enrolled in a phase II study of bevacizumab 15 mg kg(-1), capecitabine 1300 mg m(-2) daily for 2 weeks and gemcitabine 1000 mg m(-2) weekly 2 times; cycles were repeated every 21 days. Radiological response rate was 22%; progression-free survival and over survival were 5.8 and 9.8 months respectively. Grade 3 or 4 toxicities included neutropaenia (22%), thrombocytopaenia (14%), thromboembolic events (12%), hypertension (8%) and haemorrhage (6%).

Epidermal growth factor receptor-directed therapy in esophageal cancer.

Esophageal adenocarcinoma (EAC) is one of the fastest growing malignancies in the US. The long-term survival of patients with this cancer remains poor; only 25% of patients undergoing surgical excision are alive after 5 years. Multimodal programs that incorporate radiotherapy, chemotherapy and surgery for localized tumors may result in a modest survival advantage. However, significant strides in this disease can result from the inclusion of targeted therapies. The epidermal growth factor receptor (EGFR) family represents one such target and is receiving increasing attention due to the advent of specific inhibitors. Studies conducted by us and others have shown that the overexpression of EGFR family signaling intermediates is common in Barrett's esophagus and EAC. In the latter case, EGFR expression may have prognostic significance. EGFR inhibitors, including oral tyrosine kinase inhibitors and monoclonal antibodies, result in a synergistic antitumor effect with chemotherapeutic agents or with radiotherapy. Therefore, several ongoing studies include EGFR-directed therapy either alone or in combination with chemoradiotherapy for this disease. Our study of gefitinib, oxaliplatin and radiotherapy suggested that gefitinib can be safely incorporated into an oxaliplatin-based chemoradiation program for esophageal cancer, although the clinical activity of this combination is modest. Herein, we review the current literature on this subject.

[New CT program simulating kidney displacement during retroperitoneal laparoscopic nephrectomy].

A total of 12 patients with malignant localized renal or ureteral neoplasms underwent multi-slice computed tomography. Imaging data were sent to the dedicated workstation to create volume rendering and virtual laparoscopic images of the kidney which was displaced ventrally with retroperitoneal balloon. These findings were compared with video images obtained during retroperitoneal laparoscopic nephrectomy. The kidney displacement simulator depicted all renal arteries (100% sensitivity) and 13 of 14 renal veins (93% sensitivity). Hilar anatomy, including the tumor, major vessels and their relationships were visualized as in the actual laparoscopic views. The desired portions of major vessels as well as the left adrenal and gonadal veins visualized with this system completely corresponded with the actual laparoscopic images during surgery. The kidney displacement simulator is useful to foresee desired portions of major vessels and branched small vessels such as the adrenal or gonadal veins in advance of surgery. It is thus able to guide surgeons and reduce operative risks and possible complications.

The glycosylation pattern of baculovirus expressed envelope protein E2 affects its ability to prevent infection with bovine viral diarrhoea virus.

We have investigated the role of glycosylation of the envelope glycoprotein E2 of bovine viral diarrhoea virus (BVDV), produced in insect cells, in BVDV infection. When amino acids predicated to code for the C-terminal N-linked glycosylation site were mutated the resulting protein was less efficient than wild type protein at preventing infection of susceptible cells with BVDV. In addition, mutational analysis showed that a further two predicted N-terminal N-linked glycosylation sites of E2 are required for efficient production of recombinant protein.

Acetylator status, drug metabolism and disease.

Acetylation polymorphism, although discovered 40 years ago, still holds interest not only because many drugs and carcinogens are metabolized by acetylation in the liver but also because advances have been made in the understanding of the molecular genetics of acetylation. It is this genetic variation of drug metabolism that is one of the causes of inter-individual variation of the effect of a drug. Acetylation polymorphism relates to the metabolism of a number of arylamine and hydrazine drugs and carcinogens by cytosolic N-acetyltransferase--NAT2. In humans, 2 genes--NAT1 and NAT2--are responsible for the N-acetyltransferase activity. Studies have revealed several allelic variants of both NAT1 and NAT2. It has been suggested that some of these variants modify the individual susceptibility to disease.

Predictive value of ultrasonography in the diagnosis of palpable breast lump.

A lump is the first symptom in over 80 percent of all patients with cancer of the breast. Consequently, the finding of any lump in the breast is a highly significant sign and warrants a thorough investigation. The present study was undertaken to study the predictive value of ultrasonography in the diagnosis of palpable breast lumps. Fifty-two female patients with palpable breast lumps that were unilateral underwent ultrasonography of the breast. Thirty-six of these patients who had solitary, unilateral, solid lumps were followed up with FNAC/biopsy/mammography and the findings were compared. The mean age group was seen to be 41 years. The youngest patient was 17 years old and the oldest was 80 years. The validity of USG in the diagnosis of palpable breast lumps was calculated. A sensitivity value of 95%, specificity of 94.10%, positive and negative predictive values of 95.50% and 93.75% were noted and were comparable to other similar studies. The sensitivity, specificity, positive and negative predictive values were statistically significant (p=0.0000006) and were comparable to the values obtained by different studies conducted elsewhere. Among the multiple USG parameters, shape, margins, vascularity, surrounding tissue character, sound transmission through the lump were more significant in the diagnosis of benign vs. malignant lumps. Echogenicity and echotexture were of less significance.

Enhanced crystallization of the Cys18 to Ser mutant of bovine gammaB crystallin.

The cysteine residues of the gamma crystallins, a family of ocular lens proteins, are involved in the aggregation and phase separation of these proteins. Both these phenomena are implicated in cataract formation. We have used bovine gammaB crystallin as a model system to study the role of the individual cysteine residues in the aggregation and phase separation of the gamma crystallins. Here, we compare the thermodynamic and kinetic behavior of the recombinant wild-type protein (WT) and the Cys18 to Ser (C18S) mutant. We find that the solubilities of the two proteins are similar. The kinetics of crystallization, however, are different. The WT crystallizes slowly enough for the metastable liquid-liquid coexistence to be easily observed. C18S, on the other hand, crystallizes rapidly; the metastable coexisting liquid phases of the pure mutant do not form. Nevertheless, the coexistence curve of C18S can be determined provided that crystallization is kinetically suppressed. In this way we found that the coexistence curve coincides with that of the WT. Despite the difference in the kinetics of crystallization, the two proteins were found to have the same crystal forms and almost identical X-ray structures. Our results demonstrate that even conservative point mutations can bring about dramatic changes in the kinetics of crystallization. The implications of our findings for cataract formation and protein crystallization are discussed.

Molecular basis of a progressive juvenile-onset hereditary cataract.

In a recent paper, patients with a progressive juvenile-onset hereditary cataract have been reported to have a point mutation in the human gammaD crystallin gene (Stephan, D. A., Gillanders, E., Vanderveen, D., Freas-Lutz, D., Wistow, G., Baxevanis, A. D., Robbins, C. M., VanAuken, A., Quesenberry, M. I., Bailey-Wilson, J., et al. (1999) Proc. Natl. Acad. Sci. USA 96, 1008-1012). This mutation results in the substitution of Arg-14 in the native protein by a Cys residue. It is not understood how this mutation leads to cataract. We have expressed recombinant wild-type human gammaD crystallin (HGD) and its Arg-14 to Cys mutant (R14C) in Escherichia coli and show that R14C forms disulfide-linked oligomers, which markedly raise the phase separation temperature of the protein solution. Eventually, R14C precipitates. In contrast, HGD slowly forms only disulfide-linked dimers and no oligomers. These data strongly suggest that the observed cataract is triggered by the thiol-mediated aggregation of R14C. The aggregation profiles of HGD and R14C are consistent with our homology modeling studies that reveal that R14C contains two exposed cysteine residues, whereas HGD has only one. Our CD, fluorescence, and differential scanning calorimetric studies show that HGD and R14C have nearly identical secondary and tertiary structures and stabilities. Thus, contrary to current views, unfolding or destabilization of the protein is not necessary for cataractogenesis.

PANORAMA: an integrated Web-based sequence analysis tool and its role in gene discovery.

As the exponential growth of DNA sequence information in databases continues, the task of converting this deposited information into knowledge becomes more dependent on integrative sequence analysis and visualization tools. PANORAMA is an Internet-accessible software package that performs a variety of informatics analyses on a given DNA sequence and returns a visual and interactive representation of the results. Its design is modular, so that further sequence analysis tools can be integrated with minimal effort. The utility of PANORAMA is demonstrated in the analysis of 650 kb of human genomic DNA from chromosome region 3p21.3, a region of potential tumor suppressor genes involved in lung cancer, breast cancer, and other forms of cancer. PANORAMA aided in the discovery of genes and alternate splice forms of known exons, in the demarcation of intron-exon boundaries, and in the identification of promoter regions and polymorphisms, all of which contributed to a better understanding of the region. PANORAMA is available on the World Wide Web at http://atlas.swmed.edu.

Computerized polymorphic marker identification: experimental validation and a predicted human polymorphism catalog.

A computational system for the prediction of polymorphic loci directly and efficiently from human genomic sequence was developed and verified. A suite of programs, collectively called POMPOUS (polymorphic marker prediction of ubiquitous simple sequences) detects tandem repeats ranging from dinucleotides up to 250 mers, scores them according to predicted level of polymorphism, and designs appropriate flanking primers for PCR amplification. This approach was validated on an approximately 750-kilobase region of human chromosome 3p21.3, involved in lung and breast carcinoma homozygous deletions. Target DNA from 36 paired B lymphoblastoid and lung cancer lines was amplified and allelotyped for 33 loci predicted by POMPOUS to be variable in repeat size. We found that among those 36 predominately Caucasian individuals 22 of the 33 (67%) predicted loci were polymorphic with an average heterozygosity of 0.42. Allele loss in this region was found in 27/36 (75%) of the tumor lines using these markers. POMPOUS provides the genetic researcher with an additional tool for the rapid and efficient identification of polymorphic markers, and through a World Wide Web site, investigators can use POMPOUS to identify polymorphic markers for their research. A catalog of 13,261 potential polymorphic markers and associated primer sets has been created from the analysis of 141,779,504 base pairs of human genomic sequence in GenBank. This data is available on our Web site (pompous.swmed.edu) and will be updated periodically as GenBank is expanded and algorithm accuracy is improved.

Drug use in Nepal: the view from the street.

This study uses qualitative research techniques to examine heroin use in Nepal. It explores the life histories of 16 heroin users in Kathmandu, the country's capital, emphasizing those who are street children or who are otherwise displaced. The cases document that the initiation of use in Nepal is a complex process which includes: certain personality traits; an early history of culturally acceptable use of alcohol, tobacco, marijuana, or hashish; peer influence; and the specific social setting of users. Outside (i.e., foreign) influences are included in the mix, but never as a single determinant of drug use. Factors specific to the Nepali scene include the traditional association of forms of marijuana with certain religious contexts and the availability of heroin. An additional factor is the poverty of the urban setting. The approach in Nepal to dealing with drugs primarily involves a realization of the role played by the interaction between personality and social setting in the fullest meaning of that term.

Analgesic efficacy of enadoline versus placebo or morphine in postsurgical pain.

Enadoline, a selective agonist of the kappa-opioid receptor, was studied for its analgesic efficacy in patients with pain after obstetric or gynecologic surgery. An initial study involving a comparison of enadoline (2, 5, 15 micrograms), an acetaminophen-codeine (ACET/COD) combination, and placebo showed all treatments to be ineffective analgesics. Therefore, a second study with the same design but using higher doses of enadoline (15 and 25 micrograms) and replacing ACET/COD with morphine 10 mg i.m. was conducted. Enadoline 25 micrograms produced similar pain relief to that of morphine, although of shorter duration, and better than enadoline 15 micrograms or placebo. However, enadoline was associated with dose-limiting neuropsychiatric adverse events, which led to early termination of the study.

Analgesic efficacy of the kappa-receptor agonist, enadoline, in dental surgery pain.

To study the analgesic efficacy of enadoline, a selective agonist of the kappa-opioid receptor, a double-blind, randomized comparison was made of enadoline versus placebo and a combination of acetaminophen-codeine in patients with pain after surgical extraction of impacted molar teeth. An initial study involving a comparison of enadoline, a combination, and placebo failed to show any analgesic effect of enadoline. Therefore, a second study with the same design but using higher doses of enadoline was conducted. Despite continued safety and tolerability even at the higher doses, enadoline could not be shown to be superior to placebo. The acetaminophen-codeine combination was significantly more effective than enadoline or placebo. Enadoline did not show analgesic efficacy in this study. Possible reasons for this lack of efficacy are discussed.

Iatrogenic left main coronary artery stenosis.

Iatrogenic left main coronary artery stenosis is a potentially life-threatening complication of cardiac valve replacement surgery due to injury by perfusion cannulas. This requires prompt clinical recognition and diagnosis by repeat coronary angiography, and treatment by early coronary artery bypass grafting. We present 3 patients who had normal coronary arteries prior to valve replacement surgery, and who developed severe left main coronary artery stenosis after surgery. Accelerating angina and refractory ventricular arrhythmia were presenting clinical manifestations. Coronary artery bypass grafting was successfully performed in all 3 patients.

Endomyocardial biopsy causing coronary artery-right ventricular fistula after cardiac transplantation.

We present 3 cases of coronary artery-right ventricular fistulae diagnosed on yearly check-ups on 160 cardiac transplant patients between September 1982 and January 1995. The fistula was communicating with the ventricular branch of the right coronary artery, the septal branch of the left anterior descending artery and the distal right coronary artery in the three cases being reported. Histological examination of the endomyocardial biopsy specimen showed the presence of small calibre arteries which were not seen in other cases. Although endomyocardial biopsy carries a risk of less than 0.5 percent, the possibility of causing coronary artery-ventricular fistula should be added to the list of the complications of this procedure. The shunt caused by these fistulae is small and has no hemodynamic significance and usually does not warrant any treatment.