Mapping the platelet profile for functional genomic studies and demonstration of the effect size of the GP6 locus

BACKGROUND

Evidence suggests the wide variation in platelet response within the population is genetically controlled. Unraveling the complex relationship between sequence variation and platelet phenotype requires accurate and reproducible measurement of platelet response.

OBJECTIVE

To develop a methodology suitable for measuring signaling pathway-specific platelet phenotype, to use this to measure platelet response in a large cohort, and to demonstrate the effect size of sequence variation in a relevant model gene.

METHODS

Three established platelet assays were evaluated: mobilization of [Ca(2+)](i), aggregometry and flow cytometry, each in response to adenosine 5'-diphosphate (ADP) or the glycoprotein (GP) VI-specific crosslinked collagen-related peptide (CRP). Flow cytometric measurement of fibrinogen binding and P-selectin expression in response to a single, intermediate dose of each agonist gave the best combination of reproducibility and inter-individual variability and was used to measure the platelet response in 506 healthy volunteers. Pathway specificity was ensured by blocking the main subsidiary signaling pathways.

RESULTS

Individuals were identified who were hypo- or hyper-responders for both pathways, or who had differential responses to the two agonists, or between outcomes. 89 individuals, retested three months later using the same methodology, showed high concordance between the two visits in all four assays (r(2) = 0.872, 0.868, 0.766 and 0.549); all subjects retaining their phenotype at recall. The effect of sequence variation at the GP6 locus accounted for approximately 35% of the variation in the CRP-XL response.

CONCLUSION

Genotyping-phenotype association studies in a well-characterized, large cohort provides a powerful strategy to measure the effect of sequence variation in genes regulating the platelet response.

Sternotomy for substernal goitre: an otolaryngologist's perspective

Introduction:

Large substernal goitres present a challenge to the otolaryngologist due to their size and location. Predicting which patients will require sternotomy can enable planning of surgery in a specialist centre, with the assistance of a thoracic surgeon. Our aim for this study was to establish clinical and radiological predictors which would aid the otolaryngologist in the pre-operative planning of such cases.

Methods:

A retrospective medical record review was conducted for all patients undergoing thyroidectomy for substernal goitre who required sternotomy in our institution over a 10-year period.

Results:

During the study period, 140 patients with substernal goitres underwent thyroidectomy. Three patients (2 per cent) required sternotomy. These cases are described.

Conclusions:

Radiological evidence of extension of a substernal goitre to the aortic knuckle, or loss of tissue planes on computed tomography, should raise suspicion that the patient may require sternotomy for safe delivery of the gland. The otolaryngologist should plan surgery for these patients in a specialist centre, with the help of a thoracic surgeon.

Otorhinolaryngologists' interest in facial plastic surgery: a survey in the United Kingdom and Ireland

Introduction:

Within the field of otorhinolaryngology, interest in facial plastic surgery has grown significantly in recent years. There is a lack of evidence in the literature documenting this interest in the British Isles.

Materials and methods:

572 questionnaires were mailed to all members of the British Association of Otolaryngologists, Head and Neck Surgeons and to members of the Irish Otolaryngological Society.

Results:

Our response rate was 68 per cent. One-third of respondents were performing facial plastic procedures regularly, most commonly otoplasty (80 per cent), rhinoplasty (74 per cent) and facial flaps (28 per cent). Two-thirds of respondents had attended supplementary courses in facial plastic surgery, and 65 per cent would like facial plastic surgery to compose one-third of their daily practice.

Discussion:

Facial plastic surgery has become a significant part of the otorhinolaryngologists' practice. They are now offering a wider variety of procedures in the area. This is the first paper to document this interest in the United Kingdom and Ireland.

[Isolation, characterization and typing of Escherichia coil 0157:H7 strains from beef products and milk]

Shiga toxin (Stx)-producing Escherichia coli (STEC) is an emergent pathogen associated with foodborne diseases, especially foodstuffs of animal origin. A total of 250 beef samples (ground beef and hamburgers) obtained from retail outlets in Santa Fe and Santo Tomé cities, and 150 milk samples from bulk tank milk from dairy barns of the region were analyzed by selective enrichment and immunomagnetic separation. Escherichia coli O157:H7 stx2, eae and ehxA positive strains were isolated from three (1.2%) beef samples. The strains could be differentiated by pulsed-field gel electrophoresis, phagetyping and genotyping of stx. The milk samples were negative for STEC O157. These findings confirm the role of food of animal origin in the epidemiology of E. coli O157:H7 - associated diseases.

Combined mediator blockade or topical steroid for treating the unified allergic airway

BACKGROUND

Asthma and allergic rhinitis are manifestations of a single unified allergic airway, for which the best treatment is uncertain.

OBJECTIVE

To compare the anti-inflammatory efficacy in the unified allergic airway of combined oral mediator antagonism and combined topical steroid.

METHODS

Subjects with asthma and perennial allergic rhinitis entered a randomized double blind crossover study comparing montelukast 10 mg and cetirizine 10 mg to extra-fine inhaled beclomethasone 400 mcg/day and intranasal beclomethasone 200 mcg/day, each taken once daily for 2 months, after 2-week placebo washouts. Measurements were made after each washout and randomized treatment, comprising: methacholine PC20, exhaled and nasal nitric oxide, blood eosinophils and eosinophilic cationic protein, symptoms, lung and nasal function tests.

RESULTS

Seventeen patients completed per protocol. For PC20 and exhaled nitric oxide, only combined topical steroid produced improvements (P < 0.005) from placebo baseline. Combined steroid was superior by a 0.93 (95% CI 0.14-0.93, P < 0.05) doubling dilution difference for PC20 and a 0.99 (95% CI 0.9-15.1, P < 0.01) doubling difference for exhaled nitric oxide. Both treatments attenuated eosinophils and eosinophilic cationic protein, and reduced nasal symptoms (P < 0.05). Only steroid improved nasal nitric oxide (P=0.05) and asthma symptoms (P < 0.05). Neither treatment affected lung or nasal function tests.

CONCLUSION

Combined topical steroid and combined mediator antagonism both attenuated systemic inflammation in the unified allergic airway, but only the former reduced bronchial and nasal inflammatory markers. The relevance of this to exacerbations and airway remodelling needs to be defined.

Thyroid pathology and the globus symptom: are they related? A two year prospective trial

INTRODUCTION

The globus sensation is a constant feeling of a lump in the throat and may be associated with thyroid enlargement. A two year prospective study was set up to ascertain the relationship between thyroid pathology and globus symptoms.

MATERIALS AND METHODS

All patients undergoing thyroid surgery over a two year period were included. Patients were questioned pre- and post-operatively. Globus symptom scores were recorded using a visual analogue scale. The size, weight and histological features of the removed specimens were correlated and statistical analysis performed.

RESULTS

Two hundred patients were included in the study; 58 were symptomatic for globus pharyngeus pre-operatively, and 80 per cent of these patients' symptoms resolved post-operatively (p < or = 0.0001). Patients with histological features of inflammation showed the greatest improvement (p < or = 0.0001).

CONCLUSION

As many as one-third of patients with a thyroid mass will complain of a globus-like symptom. Patients undergoing thyroid surgery, who are symptomatic for globus pharyngeus, can expect that their symptoms will improve following surgery.

Experimental study of the NaK 3 3Pi double minimum state

We have used the Doppler-free, perturbation-facilitated optical-optical double-resonance technique to investigate the vibrational, rotational, and hyperfine structure of the 3 (3)Pi double minimum state of NaK. Since this electronic state arises from an avoided crossing with the nearby 4 (3)Pi state, we observe striking patterns in the data that provide a sensitive probe of the electronic wave function in the various regions of the double well potential. A single-mode cw dye laser excites 2(A) (1)Sigma(+)(v(A),J) approximately 1(b) (3)Pi(Omega=0)(v(b),J) mixed singlet-triplet "window" levels from thermally populated rovibrational ground state levels, 1(X) (1)Sigma(+)(v(X),J+/-1). Further excitation by a single-mode cw Ti:sapphire laser selects various 3 (3)Pi(0)(v(Pi),J(Pi)) rovibrational levels, which are detected by observing direct 3 (3)Pi(0)-->1(a) (3)Sigma(+) fluorescence in the green spectral region. Using the inverse perturbation approximation method, we have determined a 3 (3)Pi(0) potential curve that reproduces the measured energies to approximately 0.24 cm(-1). In addition, the hyperfine and spin-orbit constants, b(F) and A(v), have been determined for each region of the potential curve.

The NaK 1(b) 3Pi(Omega=0) state hyperfine structure and the 1(b) 3Pi(Omega=0) approximately 2(A) 1Sigma+ spin-orbit interaction

We have measured the hyperfine structure of mutually perturbing rovibrational levels of the 1(b) 3Pi0 and 2(A) 1Sigma+ states of the NaK molecule, using the perturbation-facilitated optical-optical double resonance method with copropagating lasers. The unperturbed 1(b) 3Pi0 levels are split into four hyperfine components by the Fermi contact interaction bFIS. Mixing between the 1(b) 3Pi0 and 2(A) 1Sigma+ levels imparts hyperfine structure to the nominally singlet component of the perturbed levels and reduces the hyperfine splitting of the nominally triplet component. Theoretical analysis relates these observations to the hyperfine splitting that each 1(b) 3Pi0 level would have if it were not perturbed by a 2(A) 1Sigma+ level. Using this analysis, we demonstrate that significant hyperfine splitting arises because the 1(b) 3Pi0 state cannot be described as pure Hund's case (a). We determine bF for the 1(b) 3Pi0 levels and also a more accurate value for the magnitude of the singlet-triplet spin-orbit coupling HSO=[1(b) 3Pi0(vb,J)(H(SO))2(A) 1Sigma+(vA,J). Using the known spectroscopic constants of the 1(b) 3Pi state, we obtain bF=0.009 89+/-0.000 27 cm(-1). The values of (H(SO)) are found to be between 2 and 3 cm(-1), depending on vb, vA, and J. Dividing (H(SO)) by calculated vibrational overlap integrals, and taking account of the 1(b) 3Pi(Omega) rotational mixing, we can determine the magnitude of the electronic part H(el) of H(SO). Our results yield (H(el))=(16.33+/-0.15) cm(-1), consistent with our previous determinations using different techniques.

Cardiovascular effects of long-term central and peripheral administration of urocortin, corticotropin-releasing factor, and adrenocorticotropin in sheep

The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in the stress response, have acute effects on arterial pressure. New evidence indicates that urocortin (UCN), the putative agonist for the CRF type 2 receptor, has selective cardiovascular actions. The responses to long-term infusions of these hormones, both peripherally and centrally, in conscious animals have not been studied. Knowledge of the long-term effects is important because they may differ considerably from their acute actions, and stress is frequently a chronic stimulus. The present experiments investigated the cardiovascular effects of CRF, UCN, and ACTH in conscious sheep. Infusions were made either into the lateral cerebral ventricles (i.c.v.) or i.v. over 4 d at 5 microg/h. UCN infused i.c.v. or i.v. caused a prolonged increase in heart rate (HR) (P < 0.01) and a small increase in mean arterial pressure (MAP) (P < 0.05). CRF infused i.c.v. or i.v. progressively increased MAP (P < 0.05) but had no effect on HR. Central administration of ACTH had no effect, whereas systemic infusion increased MAP and HR (P < 0.001). In conclusion, long-term administration of these three peptides associated with the stress response had prolonged, selective cardiovascular actions. The striking finding was the large and sustained increase in HR with i.c.v. and i.v. infusions of UCN. These responses are probably mediated by CRF type 2 receptors because they were not reproduced by infusions of CRF.

Upper level of the spina bifida defect: how good are we?

OBJECTIVE

To assess the accuracy of obstetric sonography in determining the upper level of myelomeningocele lesions.

METHODS

This was a retrospective study of 171 consecutive cases of spina bifida repaired in utero. The upper level of the lesion as determined by obstetric sonography was assigned by community physicians prior to referral in the second trimester and by the authors at Vanderbilt University Medical Center during preoperative evaluation. One hundred and eleven cases had levels established by plane-film X-ray or magnetic resonance imaging after delivery and this was regarded as the gold standard.

RESULTS

Of the 171 community examinations, only 29% identified a specific upper level of the lesion; our corresponding examinations specified the lesion level in all cases. Of the 111 cases that had upper levels of the lesion established by post-delivery imaging, corresponding levels were available for comparison from 35 of the community examinations and from 111 of the examinations performed at Vanderbilt. All three assigned levels were available for comparison in 35 cases. In 26% of cases, community-assigned levels agreed exactly with post-delivery levels, while 66% agreed within one level and 80% agreed within two levels. In 38% of cases, levels assigned at Vanderbilt agreed exactly with post-delivery levels, while 78% agreed within one level and 96% agreed within two levels. Upper levels of the lesion assigned at Vanderbilt were significantly more accurate overall compared with those assigned by community physicians (signed rank test [paired comparison], P = 0.048). However, comparison of lesion levels assigned at Vanderbilt in the first 50 vs. the last 61 cases revealed a significant learning effect (Fisher's exact test, P = 0.03). When comparison of lesion levels assigned by community physicians was restricted to the first 50 cases at Vanderbilt, accuracy was similar (n = 13; t-test, P = 0.16; rank sum test, 0.31).

CONCLUSIONS

Community physicians were successful in assigning the upper level of the spina bifida lesion only 29% of the time. When successful, the accuracy of these determinations was similar to that of the authors at Vanderbilt. A significant learning effect was demonstrated by improved accuracy over time at Vanderbilt. A concerted continuing medical education effort is indicated to improve the imaging skills of physicians in the accurate diagnosis of the severity of spina bifida in fetuses.

Molecular analysis of Fiji disease virus genome segments 5, 6, 8 and 10

The complete sequences of Fiji disease virus (FDV) genome segments 5 (S5), S6, S8 and S10 were obtained and comprised 3150 nt, 2831 nt, 1959 nt and 1819 nt, respectively. Each segment contained a single ORF which encoded putative proteins of 115 kDa, 97 kDa, 69 kDa and 63.0 kDa, respectively. The putative amino acid sequences encoded by S5 and S6 contained putative leucine zipper motifs while FDV S5 and S8 each contained an ATP-GTP-binding motif. At the amino acid level, FDV S5, S6, S8 and S10 showed most similarity to the corresponding segments of Rice black-streaked dwarf virus. Based on sequence similarities, it is predicted that FDV S8 encodes a minor core protein, while FDV S10 encodes an outer capsid protein. The evolutionary relationships of FDV to other reoviruses are discussed.

Wegener's granulomatosis masquerading as unilateral sinusitis

Wegener's Granulomatosis (WG) is a rare, multi-system disease of unknown aetiology. The disease is characterised by necrotizing granulomas and vasculitis of the upper and lower respiratory tracts and kidneys. The sinonasal region may be the first area to manifest this systemic condition. If the disease is diagnosed early and treated appropriately, involvement of the lungs and kidneys may be averted. Left untreated, the disease may prove rapidly fatal. A low threshold of clinical suspicion must be maintained. We report a case, of a middle aged patient who presented with unilateral sinusitis secondary to a large obstructive nasal mass. Anti neutrophil cytoplasmic antibody (ANCA) titres helped confirm the diagnosis of WG. Unilateral sinusitis with a nasal mass, is a very unusual presentation of WG, and emphasises the importance of a low threshold of suspicion for patients presenting with atypical sinonasal symptoms.

Survival after liver transplantation for hepatocellular carcinoma

BACKGROUND

Selection criteria for patients with hepatocellular carcinoma (HCC) suitable for liver transplantation (LT) include tumor size and number and vascular invasion. There has been a recent trend to expand the transplant criteria for HCC. We reviewed our experience to determine survival following LT based on tumor characteristics.

METHODS

A retrospective analysis was performed on 72 patients with HCC who underwent LT between 1985 and July 2002. The Milan criteria were applied for LT candidacy for HCCs that were deemed unresectable from anatomical considerations and/or the severity of underlying cirrhosis. Patients were divided into four groups: group 1: patients with known HCC who satisfied the selection criteria (n = 22); group 2: patients with known HCC that exceeded the criteria (n = 17); group 3: patients with incidental HCC found at pathological examination of the explant (n = 33); group 4: contemporary LT recipients without HCC (n = 935).

RESULTS

In the known HCC group, the interval between listing as status 2 and transplantation was 72.2 +/- 133.6 days (median 23 days). Three-year patient survival was 80.2% in group 1, 35.8% in group 2, 63.2% in group 3, and 81.5% in group 4. In group 2 patients, the tumors were significantly larger, had more nodules, and were more often bilobar. In group 3, five (15%) exceeded the criteria mainly because of tumor size and four patients died within 3 years post-LT (three from tumor recurrence).

CONCLUSION

Liver transplantation for HCC yields acceptable survival in early-stage tumors, particularly if transplanted soon after listing. Long-term survival was inferior in patients with multiple tumors and tumors that were greater than 5 cm in diameter.