Transcoronary sinus administration of autologous bone marrow in patients with chronic refractory stable angina Phase 1

PURPOSE

Based on our preclinic studies with autologous unfractionated bone marrow (AUBM) via coronary sinus with transitory occlusion, a clinic study in patients with chronic stable angina was designed. The objectives were to evaluate safety, tolerance and feasibility.

METHODS AND MATERIALS

A multicenter prospective study with inclusion and exclusion criteria defined by an Independent Clinical Committee was carried out. Fourteen patients underwent transcoronary sinus administration of freshly aspirated and filtered AUBM (60-120 ml). Safety and tolerance were evaluated. Feasibility was evaluated with Seattle Angina Questionnaire (SAQ), Canadian Cardiovascular Society (CCS) angina classification (baseline-Day 180), myocardial perfusion (baseline-Day 90) with independent core laboratory and coronary angiography (baseline and Day 30).

RESULTS

There were no changes in the safety and tolerance parameters. Preliminary clinical efficacy at Day 180 disclosed a significant improvement of 38%, evaluated by the SAQ. The CCS angina classification shows that the mean angina class was 3.0+/-0.55 at baseline and improved to 2.0+/-0.00 at Day 180 (P <.001). Semiquantitative radionuclide perfusion imaging (core lab) showed a significant improvement at Day 90 in 13/14 patients, with a mean improvement of 24% at rest (P <.01) and 33% at stress (P <.05). Coronary angiography showed more collateral vessels in 9/14 patients.

CONCLUSIONS

We can conclude that AUBM via coronary sinus with transitory occlusion is tolerable and safe. Significant improvement in the myocardial perfusion at Day 90 and in the quality of life at Day 180 was observed.

Spinal injuries admitted to a specialist centre over a 5-year period: a study to evaluate delayed admission

STUDY DESIGN

Retrospective study of 432 patients admitted to our institution with a spinal injury over a 5-year period.

OBJECTIVES

To present epidemiological data relating to this spinal population, reporting specifically on delayed admission and length of hospitalisation.

SETTING

Royal National Orthopaedic Hospital, Stanmore, UK.

METHODS

A total of 432 traumatic spinal injuries admitted between March 1998 and March 2003 were analysed with respect to age, gender, mechanism of injury, level of bony injury, neurological level (complete, incomplete and intact), Injury Severity Score (ISS), date of injury, referral and admission independently and length of hospitalisation. The delays between injury and referral (>3 days) and between referral and admission (>7 days) were correlated to the length of hospitalisation. A detailed analysis of the cause of delay at both junctures was undertaken.

RESULTS

There were 322 males (average age, 38.6 years) and 110 females (average age, 41.8 years) in our study. Classification of neurological severity disclosed 108 complete injuries, 115 incomplete and 209 intact. The average time between injury and referral was 5.5 days (range 0-94), and between referral and admission was 10.7 days (range 0-130). A total of 161 patients (37%) experienced a delay between injury and referral, of whom 59 (37%) were subsequently also delayed to admission. The principal reason for delay between injury and referral was the treatment of concurrent injuries. Even patients with complete injuries (15/43) experienced delayed referral. In all, 112 patients (26%) experienced a delay between referral and admission. Principal reasons included the provision of beds (Intensive care, acute and rehabilitation) and physiological stabilisation of other injuries particularly thoracic trauma.

CONCLUSIONS

Provision of beds remains the most common preventable reason for delay between referral and admission and is associated with increased hospitalisation. Early liaison with a designated spinal injuries unit, particularly those with cord injury remains vitally important.

Hepatoprotective effects of Hibiscus, Rosmarinus and Salvia on azathioprine-induced toxicity in rats

As an anti-metabolite, Azathioprine inhibits the de novo and salvage pathways of purine synthesis. Intraperitoneal injection of this drug results in not only lymphocyte suppression but also toxicity to bone marrow, gastrointestinal tract, and liver. This Azathioprine-induced hepatotoxicity was found to be associated with oxidative damage. Plants with antioxidative properties have been traditionally used to prevent diseases associated with free radicals. In this report, we used water extracts of three herbal plants that have been commonly used for treating many illnesses (Hibiscus sabdariffa, Rosmarinus officinalis and Salvia officinalis). Here we show their novel hepatoprotective effects against Azathioprine-induced hepatotoxicity in rats. Typically, administration of Azathioprine induces oxidative stress through depleting the activities of antioxidants and elevating the level of malonialdehyde in liver. This escalates levels of alanine aminotransferase, and aspartate aminotranferase in serum. Pretreatment with any of the three herbal plants used in this investigation proved to have a protective effect against Azathioprine-induced hepatotoxicity. Animals pretreated with water extracts from any of the three herbs under investigation not only failed to show necrosis of the liver after azathioprine administration, but also retained livers that, for the most part, were histologically normal. In addition, these herbs blocked the induced elevated levels of alanine aminotransferase and aspartate aminotranferase in serum. The Azathioprine-induced oxidative stress was relieved to varying degrees by the examined herbal extracts. This effect was evident through reducing malonialdehyde levels and releasing the inhibitory effect of Azathioprine on the activities of glutathione, catalase and superoxide dismutase. To our knowledge, this report is the first that shows hepatoprotective effects of Hibiscus, Rosmarinus and Salvia species against Azathioprine-induced acute liver damage.

Adipose tissue at entheses: the rheumatological implications of its distribution. A potential site of pain and stress dissipation?

OBJECTIVES

To describe the distribution of adipose tissue within and adjacent to entheses in order to assess its functional significance at attachment sites.

METHODS

Entheses were removed from 29 different sites in the limbs of formalin fixed, elderly, dissecting room cadavers and the samples prepared for paraffin and/or methylmethacrylate histology. Entheses from four young volunteers with no history of significant musculoskeletal injury were examined by magnetic resonance imaging using T(1) weighted sequences.

RESULTS

Adipose tissue was present at several different sites at numerous entheses. Many tendons/ligaments lay on a bed of well vascularised, highly innervated, "insertional angle fat". Endotenon fat was striking between fascicles, where entheses flared out at their attachments. It was also characteristic of the epitenon, where it occurred in conjunction with lamellated and Pacinian corpuscles. Fat filled, meniscoid folds often protruded into joint cavities, immediately adjacent to attachment sites.

CONCLUSION

Adipose tissue is a common feature of normal entheses and should not be regarded as a sign of degeneration. It contributes to the increase in surface area of attachment sites, promotes movement between tendon/ligament and bone, and forms part of an enthesis organ that dissipates stress. The presence of numerous nerve endings in fat at attachment sites suggests that it has a mechanosensory role and this could account for the rich innervation of many entheses. Because damage to fat is known to lead to considerable joint pain, our findings may be important for understanding the site of pain in enthesopathies.

Is there a role for surgery in the management of dropped head syndrome?

We present a 50-year-old chronic epileptic man with a long-standing head drop, who fell sustaining multilevel thoracic vertebral body fractures. The antiepileptic medication was thought to be responsible for his osteoporosis and dropped head. We review the aetiology of the dropped head and report on our experience of surgery for this rare and disabling condition.

Stevens Johnson syndrome in Pakistan: a ten-year survey

OBJECTIVE

A pre-tested questionnaire-based, retrospective study to highlight the causative factors, mode of presentation, complications and outcome of patients with Stevens Johnson syndrome.

SETTING

Aga Khan University Hospital over a 10 year period.

METHODS

All case records with a diagnosis of Steven Johnson Syndrome in the period 1990 to 2000 were retrospectively reviewed. Data was retrieved on a comprehensive questionnaire. The demographic variatbles and drugs taken within the previous 21 days were noted. Date analysis was done by Epi-Info Version 6.0.

RESULTS

Of the 101 studied patient files, the most common offender was found to be the Penicillins as a group and Sulfadoxine-Pyrimethamine (Fansidar) when considering all drugs individually. Most common complications included electrolyte disturbances (13.9%) and congestive heart failure (6.9%). Mortality rate was high at 10.1%.

CONCLUSION

SJS was found to be a rare condition but having a mortality rate of 10.1%. As it can be induced by a large number of drugs, caution should be practiced while prescribing.

Anthrax: pathological aspects in autopsy cases in Shiraz, Islamic Republic of Iran, 1960-2001

Anthrax, like tuberculosis, shows a new epidemic spread in industrialized countries, revealing some ambiguous aspects to the disease and providing new challenges to medicine. Shiraz University of Medical Sciences has records of 7130 autopsies performed in the past 40 years, 33 of which are anthrax cases. We reviewed all the pathology slides of these cases and classified the organs involved in a search for unrecognized microscopic findings. The most common cause of death was sepsis, caused by organ involvement and direct cytotoxicity of Bacillus anthracis, in addition to its exotoxin production. Novel findings included hyaline membrane formation in respiratory system cases that is similar to acute [adult] respiratory distress syndrome and evidence of primary gastrointestinal involvement, showing the ability of the organism to pass the gastric barrier

Audit of Neurosurgery Senior House Officer training in the United Kingdom and Eire: a postal survey

An audit was performed to describe the current training conditions of senior house officers in neurosurgery in the UK and Eire. A postal questionnaire was sent to all neurosurgery senior house officers in a 6-month training period between February and August 2003. The questionnaire covered most aspects of working pattern, training and job satisfaction by the end of the 6-month post. The results from the audit showed that there are deficiencies in certain areas of the current system being employed for senior house officer training. Improvements to this training system in line with the establishment of a generic neurosciences training programme will benefit future surgical trainees.

Anthrax: pathological aspects in autopsy cases in Shiraz, Islamic Republic of Iran, 1960-2001

Anthrax, like tuberculosis, shows a new epidemic spread in industrialized countries, revealing some ambiguous aspects to the disease and providing new challenges to medicine. Shiraz University of Medical Sciences has records of 7130 autopsies performed in the past 40 years, 33 of which are anthrax cases. We reviewed all the pathology slides of these cases and classified the organs involved in a search for unrecognized microscopic findings. The most common cause of death was sepsis, caused by organ involvement and direct cytotoxicity of Bacillus anthracis, in addition to its exotoxin production. Novel findings included hyaline membrane formation in respiratory system cases that is similar to acute (adult) respiratory distress syndrome and evidence of primary gastrointestinal involvement, showing the ability of the organism to pass the gastric barrier.

Detection of Cryptosporidium amongst diarrhoeic and asymptomatic children in Jeddah, Saudi Arabia

Between the March and May of 2000, stool specimens were collected from children aged <5 in six pre-school crèches and clinics in the Jeddah area of Saudi Arabia. Sixty-three (25%) of the children had diarrhoeal disease but the other 190 were asymptomatic. When the stool samples were stained and examined for the oocysts of Cryptosporidium spp. and other enteric protozoa, 20 (32%) of the symptomatic children but only nine (4.7%) of the asymptomatic were found to be excreting Cryptosporidium oocysts. Similarly, Cyclospora cayetanensis was found, always as a co-infection with Cryptosporidium sp., in seven (11%) of the children with diarrhoeal disease but only eight (4.2%) of the asymptomatics. One asymptomatic child was found to be co-infected with Isospora belli and Cryptosporidium. Giardia intestinalis and cysts of Entamoeba histolytica/dispar were detected in 18 (29%) and nine (14%) of the children with diarrhoeal disease and in eight (4.2%) and 13 (6.8%) of the asymptomatic children, respectively. This appears to be the first report of Cy. cayetanensis from Saudi Arabia and the highest prevalence of Cryptosporidium infection ever described.

Effect of post-mortem changes on peripheral and central whole blood and tissue clozapine and norclozapine concentrations in the domestic pig (Sus scrofa)

Interpretation of the results of psychoactive or other drug measurements in post-mortem blood specimens may not be straightforward, in part because analyte concentrations in blood may change after death. There is also the issue of comparability of plasma (or serum) results to those obtained in whole blood. To investigate these problems with respect to clozapine, this drug (10mg/kg daily) was given orally to two pigs. Blood was collected 3h post-dose on day 7, the animals were sacrificed, and blood taken from central and peripheral veins for up to 48 h after death. Tissue samples were also collected immediately after death and at 48 h. Ante-mortem whole blood clozapine/N-desmethylclozapine (norclozapine) concentrations were 0.86/1.07 and 1.11/1.15 mg/l in pigs 1 and 2, respectively. Blood clozapine and norclozapine concentrations generally increased after death (central vein: clozapine up to 300%, norclozapine up to 460%; peripheral vein: clozapine up to 155%, norclozapine up to 185%). Initial blood and kidney clozapine and norclozapine concentrations were comparable in both animals, but were some two-fold higher in heart, liver and striated muscle in pig 2. In both animals, the heart and striated muscle clozapine and norclozapine concentrations had increased some two- to three-fold at 48 h, whilst the liver and kidney concentrations were essentially unchanged. The reason for the increase in heart and striated muscle concentrations at 48 h is unclear, but could be simple variation in sample site. The plasma:whole blood distribution of clozapine and norclozapine was studied in vitro. In human blood (one volunteer donor, haematocrit 0.50) the plots of plasma versus whole blood concentration were linear for both analytes across the range 0.1-1.5mg/l, although clozapine favoured plasma (plasma:whole blood ratio=1.12), whereas norclozapine favoured whole blood (ratio 0.68). In pig blood, the plots of plasma versus whole blood were non-linear in both cases, although clozapine favoured plasma to a greater extent than norclozapine. This may be due to lower plasma clozapine and norclozapine protein binding capacity in the pig as compared to man.

Gastric adenocarcinoma missed at endoscopy

BACKGROUND AND PURPOSE

The diagnosis of gastric cancer is based on histological confirmation at endoscopy with the emphasis on early detection to improve prognosis. The aims of this study were to identify the proportion of patients with gastric adenocarcinoma in whom the diagnosis was missed at first endoscopy and the subsequent delay which occurred before the histological diagnosis was established.

METHODS

Retrospective review of 137 consecutive patients with biopsy-proven gastric adenocarcinoma presenting to one surgical unit over a five-year period.

RESULTS

Two patients with a biopsy diagnosis at laparotomy and 6 patients in whom case notes could not be traced were excluded from the study. Of the remaining 129 patients, the diagnosis of gastric adenocarcinoma was missed at first endoscopy in 18 (14%). The median delay to histological diagnosis in this subgroup of patients was 13 weeks (range 3-102).

CONCLUSION

Delays in establishing the diagnosis of gastric adenocarcinoma following initial endoscopy occur in a number of patients. Greater suspicion and a more rigorous protocol for repeat endoscopy and biopsy must be implemented in order to reduce the number of missed diagnoses after initial endoscopy.

Blocking the effects of IL-1 in rheumatoid arthritis protects bone and cartilage

Destruction of articular joints occurs progressively in patients with rheumatoid arthritis (RA). Although the exact aetiology of RA has not been fully elucidated, a large body of evidence supports a role for interleukin-1 (IL-1) in cartilage and bone erosion. In vitro studies suggest that IL-1 can cause cartilage destruction by stimulating the release of matrix metalloproteinases and other degradative products, and it can increase bone resorption by stimulating osteoclast differentiation and activation. In animal models of RA, blocking the effects of IL-1 with either IL-1 receptor antagonist (IL-1Ra; endogenous), anti-IL-1 monoclonal antibodies, or soluble IL-1 type II receptors significantly reduced cartilage destruction and bone erosion. Gene therapy with IL-1Ra was also effective in reducing joint destruction in experimental RA and osteoarthritis (OA) models. In clinical studies, anakinra, a human recombinant IL-1 receptor antagonist (IL-1ra; exogenous), significantly slowed radiographic progression of RA relative to placebo and significantly reduced clinical symptoms when used as monotherapy or in addition to existing methotrexate therapy. These results demonstrate that blocking IL-1 protects bone and cartilage from progressive destruction in RA.

Group B streptococcal serotype distribution of isolates from colonized pregnant women at the time of delivery in United Arab Emirates

OBJECTIVE

To determine the maternal colonization rate with group B streptococcus (GBS) and to identify the most frequent GBS serotypes occurring in UAE women during labour.

STUDY DESIGN

From February 1998 to January 1999, five hundred and sixty three pregnant women from a similar socio-economic and ethnic population were enrolled for the study. High vaginal swab cultures for GBS were obtained at the time of admission for delivery. Isolates were classified according to their capsular polysaccharide types (Ia, Ib, Ic, II-V) and c protein antigen compound.

RESULTS

Fifty-seven (10.1%) of 563 mothers were found to be carriers of GBS. Among the isolates, serotype IV (26.3%) predominated followed by type Ia (21.0%), type III (17.6%), type V (12.3%) and nontypeable, which accounted for 15.8%.

CONCLUSIONS

In view of the unknown status for GBS carrier rates in our community, this study suggests that about 10% of UAE women are colonized with group B streptococcus at delivery. The serotype distribution of the isolates in this population is different than those reported elsewhere with type IV predominating followed by type Ia and III.

Utilization of hydralazine hydrochloride in the Potentiometric Determination of Osmium(VIII): Analysis of Binary and Ternary Mixtures

A simple, rapid and accurate potentiolnetric method is described for tliedetermination of Os(VIII) in tlie co~icentrationr ange 0.4-4.0 mg/ml. Tlie method isbased on tlie addition of hydralazine hydrochloride to Os(VIII) to reduce it to Os(IV). The excess of hydralazine hydrocliloridew as oxidized by iodine dissolved ill acetic acid. The liberated iodide was then potentiometrically titrated against mercury(II) using silver amalgam as the indicator electrode. The potential of this method for sime- microdetermination is important in practical applications where tlie above reaction should proceed quantitatively towards completion. The relative standard deviation for six replicate deterinination of osmium(VIII) in binary andternary mixtures without the need for extraction or heating.

Typing of drug resistant isolates of Mycobacterium tuberculosis from India using the IS6110 element reveals substantive polymorphism

We investigated IS6110 polymorphism in clinical isolates of Mycobacterium tuberculosis from patients attending the outpatient department at various hospitals in northern India. DNA fingerprinting of 126 clinical isolates of M. tuberculosis was carried out using restriction fragment length polymorphism (RFLP) associated with the IS6110 element in M. tuberculosis genomes. A substantive degree of polymorphism was evident in the MDR M. tuberculosis isolates. The number of bands in the fingerprints varied from 0 to 19. However, the lack of common bands made it difficult to cluster the majority of these isolates. We were also unable to associate drug resistance with IS6110 copy number. Specific regions of the gyrA and katG genes from a representative number of these isolates were sequenced to determine the genotype. The majority of the isolates analyzed were found to belong to Group 1, indicating that these strains were evolutionarily older. We find no evidence of the W strain, prevalent in the US, in our study. The epidemiological patterns of the various strains in India seem to be very complex, as reflected by the presence of a large number of different strains (types) within north India.

Spectrophotometric Estimation of Cefuroxime and Ceftazidime in Bulk and in Dosage Forms

Three simple, accurate and sensitive spectrophotometric methods (A, B and C) for the determination of cefuroxime and ceftazidime in bulk samples and in dosage forms are described. They are based on the reaction with nitrous acid forming a nitroso derivatives which can be measured at λmax 350 and 355 nm for cefuroxime (I) and ceftazidime (II), respectively (method A) or by oxidation of drug I or II with an excess of freshly prepared hypobromite and the residual hypobromite was treated with sodium fluorescein at the optimum experimental conditions and measured at λmax at 517 nm (method B). Method C is based on the formation of tris (0-phenanthroline) iron(II) complex (ferroin) upon the oxidation of the studied drug I or II with an iron (III)-o-phenanthroline mixture in acetate buffer solution of pH 3.6 and measuring at λmax 509 nm. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 0.2 – 6.0, 0.2 – 3.2 and 0.1 – 5.6 μg ml−1 for methods A, B and C, respectively. The apparent molar absorptivity, Sandell sensitivity, detection and quantitation limits were calculated. For more accurate results, Ringbom optimum concentration range was 0.2 – 5.6 μg ml−1. The validity of the proposed methods was tested by analysing dosage forms containing the studied drugs I and II. The relative standard deviations were ≤ 1.25% with recoveries 98.6 – 101.4% .

Extractive Spectrophotometric Determination of Nortriptyline Hydrochloride Using Sudan II, IV and Black B

A simple spectrophotometric methods has been developed for the determination of nortriptyline hydrochloride in pure and in pharmaceutical formulations based on the formation of ion-pair complexes with sudun II (SII), sudan (IV) (SIV) and sudan black B (SBB). The selectivity of the method was improved through extraction with chloroform. The optimum conditions for complete extracted colour development were assessed. The absorbance measurements were made at 534, 596 and 649 nm for SII, SIV and SBB complexes, respectively. The calibration graph was linear in the ranges 0.5- 280. 0.5- 37.5 and 0.5 – 31.0 μg ml−1 of the drug usiny the same reagents, respectively. The precision of the procedure was checked by calculating the relative standard deviation of ten replicate determinations on 15 μg ml−1 of nortriptyline HCI and was found to be 1.7, 1.3 and 1.55% using SII, SIV, and SBB complexes, respectively. The molar absorptivity and Sandell sensitivity for each ion-pair were calculated. The proposed methods were successfully applied to the deterniination of pure nortriptyline HCI and in pharmaceutical formulations, and the results demonstrated that the method is equally accurate, precise and reproducible as the official method.

Activation of stress-activated protein kinase in osteoarthritic cartilage: evidence for nitric oxide dependence

OBJECTIVE

We have demonstrated in bovine chondrocytes that nitric oxide (NO) mediates IL1 dependent apoptosis under conditions of oxidant stress. This process is accompanied by activation of c-Jun NH2-terminal kinase (JNK; also called stress-activated protein kinase). In these studies we examined activation of JNK in explant cultures of human osteoarthritic cartilage obtained at joint replacement surgery and we characterized the role of peroxynitrite to act as an upstream trigger.

DESIGN

A novel technique to isolate chondrocyte proteins (<10% of total cartilage protein) from cartilage specimens was developed. It was used to analyse JNK activation by a western blot technique. To examine the hypothesis that chondrocyte JNK activation is a result of increased peroxynitrite, in vitro experiments were performed in which cultured chondrocytes were incubated with this oxidant.

RESULTS

Activated JNK was detected in the cytoplasm of osteoarthritis (OA) affected chondrocytes but not in that of controls. In vitro, chondrocytes produce NO and superoxide anion. IL-1 (48 h), which induces nitric oxide synthase, resulted in an activation of JNK; this effect was reversed by N-monomethylarginine (NMA). TNFalpha treated chondrocytes at 48 h produce superoxide anion (EPR method). Exposure of cells to peroxynitrite led to an accumulation of intracellular oxidants, in association with JNK activation and cell death by apoptosis.

CONCLUSION

We suggest that JNK activation is among the IL-1 elicited responses that injure articular chondrocytes and this activation of JNK is dependent on intracellular oxidant formation (including NO peroxynitrite). In addition, the extraction technique here described is a novel method that permits the quantitation and study of proteins such as JNK involved in the signaling pathways of chondrocytes within osteoarthritic cartilage.

Measurement of blood flow and oxygen tension in adjacent tissues in pedicled and free flap head and neck reconstruction

The purpose of this study was to evaluate blood flow and transcutaneous partial oxygen pressure (TcPO(2)) in adjacent tissues to free and pedicled flaps following reconstructive procedures used in conjunction with radical surgery for head and neck cancers. Fifty patients were included. Fourteen patients had reconstruction with pedicled flaps and 36 with free flaps. For each patient, TcPO(2) and laser Doppler flow measurements were taken at the center of the flap, in adjacent tissue, and in a corresponding contralateral site. Three laser Doppler measurements were performed at each site and a mean value recorded. All patients had undergone reconstruction up to 6 months prior to the time of the measurements. The collected data were analyzed using a Wilcoxon signed rank test. There were no statistically significant differences in partial oxygen tension or laser Doppler values between tissues adjacent to free compared to pedicled flaps. Although there is strong evidence to support that free flaps have improved blood flow and partial oxygen tension over pedicled flaps, further study is required to evaluate adjacent tissues. Flap choice may assist with alteration in blood flow in less favorable defects such as those in previously irradiated fields and those resulting from burn scars or chronic infections.

Epidermal growth factor receptor signaling activates orthodenticle expression during Drosophila head development

The relation between signal transduction pathways and the genes that specify regional identity remains poorly understood. We investigated the interaction between the epidermal growth factor receptor (EGFR) pathway and the homeobox gene orthodenticle (otd), which specifies cell fate during head development. Previous studies of head formation in Drosophila melanogaster demonstrated that reducing either EGFR signaling or otd expression in the imaginal primordium of the dorsal head capsule eliminates the ocelli and other dorsal head structures. Here, we show that blocking EGFR signaling reduces otd expression and that activating EGFR signaling outside this primordium induces ectopic otd expression. We also demonstrate that loss of EGFR can be rescued by constitutive otd expression. Our results indicate that otd is a downstream target of the EGFR pathway during head development.

Retinal vein thrombosis associated with chronic hepatitis C: a case series and review of the literature

The role of procoagulant autoantibodies in hepatitis C virus (HCV) infection is unclear. Three individuals with HCV infection and a unique genetic hypercoagulable state developed retinal vein thrombosis (RVT) in association with interferon-alpha (IFN-alpha) therapy. It is probable that a combination of active HCV infection in a genetically susceptible individual receiving IFN-alpha accounted for the observed RVT.

Selection of antibiotic-resistant bacterial mutants: allelic diversity among fluoroquinolone-resistant mutations

To obtain a general framework for understanding selection of antibiotic-resistant mutants, allelic diversity was examined with about 600 fluoroquinolone-resistant mutants of mycobacteria. Selection at low fluoroquinolone concentration produced many low-level resistance mutants. Some of these contained mutations that conferred unselected antibiotic resistance; none contained alterations in the quinolone-resistance-determining region of the GyrA protein, the principal drug target. As selection pressure increased, a variety of GyrA variants became prevalent. High concentrations of antibiotic reduced the variety to a few types, and eventually a concentration was reached at which no mutant was recovered. That concentration defined a threshold for preventing the selection of resistance. The pattern of variants selected, which was also strongly influenced by antibiotic structure, readily explained the variants present in clinical isolates. Thus, resistance arises from selection of mutants whose identity depends on drug concentration and structure, both of which can be manipulated to restrict selection.

Negligible genetic diversity of mycobacterium tuberculosis host immune system protein targets: evidence of limited selective pressure

A common theme in medical microbiology is that the amount of amino acid sequence variation in proteins that are targets of the host immune system greatly exceeds that found in metabolic enzymes or other housekeeping proteins. Twenty-four Mycobacterium tuberculosis genes coding for targets of the host immune system were sequenced in 16 strains representing the breadth of genomic diversity in the species. Of the 24 genes, 19 were invariant and only six polymorphic nucleotide sites were identified in the 5 genes that did have variation. The results document the highly unusual circumstance that prominent M. tuberculosis antigenic proteins have negligible structural variation worldwide. The data are best explained by a combination of three factors: (i) evolutionarily recent global dissemination in humans, (ii) lengthy intracellular quiescence, and (iii) active replication in relatively few fully immunocompetent hosts. The very low level of amino acid diversity in antigenic proteins may be cause for optimism in the difficult fight to control global tuberculosis.

Characterization of Mycobacterium tuberculosis isolates from patients in Houston, Texas, by spoligotyping

Mycobacterium tuberculosis isolates (n = 1,429) from 1,283 patients collected as part of an ongoing population-based tuberculosis epidemiology study in Houston, Texas, were analyzed by spoligotyping and IS6110 profiling. The isolates were also assigned to one of three major genetic groups on the basis of nucleotide polymorphisms located at codons 463 and 95 in the genes (katG and gyrA) encoding catalase-peroxidase and the A subunit of DNA gyrase, respectively. A total of 225 spoligotypes were identified in the 1,429 isolates. There were 54 spoligotypes identified among 713 isolates (n = 623 patients) assigned to 73 IS6110 clusters. In addition, among 716 isolates (n = 660 patients) with unique IS6110 profiles, 200 spoligotypes were identified. No changes were observed either in the IS6110 profile or in the spoligotype for the 281 isolates collected sequentially from 133 patients. Five instances in which isolates with slightly different spoligotypes had the same IS6110 profile were identified, suggesting that in rare cases isolates with different spoligotypes can be clonally related. Spoligotypes correlated extremely well with major genetic group designations. Only three very similar spoligotypes were shared by isolates from genetic groups 2 and 3, and none was shared by group 1 and group 2 organisms or by group 1 and group 3 organisms. All organisms belonging to genetic groups 2 and 3 failed to hybridize with spacer probes 33 to 36. Taken together, the results support the existence of three distinct genetic groups of M. tuberculosis organisms and provide new information about the relationship between IS6110 profiles, spoligotypes, and major genetic groups of M. tuberculosis.

Therapy and drug resistance in malaria

The aim of this study was to highlight the high degree of clinical resistance of P. falciparum and also of P. vivax to chloroquine and also the importance of early diagnosis and prompt treatment. Ninety cases of smear positive malaria aged between 6 months to 14 years were studied with regards to clinical manifestations, management and outcome. Criteria for drug resistance were absence of clearance of parasitemia and/or persistance of fever after 72 hours of therapy. Chloroquin resistance was noted in 15 (62.5%) cases of falciparum malaria and 15 (51.7%) cases of vivax malaria. The resistant and complicated cases were treated with quinine. Four (6.6%) cases were resistant to quinine and responded to artemether. There was no mortality. Early reporting of cases, frequent sampling malarial parasite, prompt diagnosis of falciparum malaria, early institution of appropriate therapy and awareness of choloquine and/or quinine resistance helps in salvaging lives.

Laser in situ keratomileusis for correction of myopia and astigmatism after penetrating keratoplasty

PURPOSE

To determine the safety and effectiveness of laser in situ keratomileusis (LASIK) for visual rehabilitation of residual myopia and astigmatism after penetrating keratoplasty.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

LASIK was performed on 23 eyes of 22 patients unable to wear glasses or contact lenses after penetrating keratoplasty due to anisometropia, high astigmatism, and/or contact lens-intolerance.

METHODS

All patients underwent LASIK for visual rehabilitation after penetrating keratoplasty. Uncorrected visual acuity and best spectacle-corrected visual acuity, degree of anisometropia, and corneal transplant integrity were recorded before surgery, as well as at 1 month, 3 months, 6 months, and 12 months after LASIK surgery.

RESULTS

The mean spherical equivalent before surgery was -7.58+/-4.42 diopters (D), which was reduced to -1.09+/-2.01 D, -0.79+/-1.84 D, -0.77+/-1.25 D, and -1.57+/-1.20 D, respectively, at 1, 3, 6, and 12 months after LASIK. The mean cylinder before surgery was 3.64+/-1.72 D, which was reduced to 1.98+/-1.15 D, 1.64+/-1.14 D, 1.48+/-0.92 D, and 1.29+/-1.04 D, respectively, at 1, 3, 6, and 12 months after LASIK. Spherical equivalent anisometropia was reduced from a mean of 6.88+/-4.4 D to 1.42+/-1.05 D at the final examination. Best-corrected visual acuity remained the same or improved in 21 of 23 eyes and decreased by 1 and 3 lines in 2 patients. There were no surgical flap or corneal transplant complications.

CONCLUSIONS

LASIK is a viable treatment alternative for myopia and astigmatism after penetrating keratoplasty in patients who are contact lens-intolerant. LASIK is more effective in treating myopia than astigmatism after penetrating keratoplasty.