The EffecTs of Amlodipine and other Blood PREssure Lowering Agents on Microvascular FuncTion in Small Vessel Diseases (TREAT-SVDs) trial: Study protocol for a randomised crossover trial

Background

Hypertension is the leading modifiable risk factor for cerebral small vessel diseases (SVDs). Yet, it is unknown whether antihypertensive drug classes differentially affect microvascular function in SVDs.

Aims

To test whether amlodipine has a beneficial effect on microvascular function when compared to either losartan or atenolol, and whether losartan has a beneficial effect when compared to atenolol in patients with symptomatic SVDs.

Design

TREAT-SVDs is an investigator-led, prospective, open-label, randomised crossover trial with blinded endpoint assessment (PROBE design) conducted at five study sites across Europe. Patients aged 18 years or older with symptomatic SVD who have an indication for antihypertensive treatment and are suffering from either sporadic SVD and a history of lacunar stroke or vascular cognitive impairment (group A) or CADASIL (group B) are randomly allocated 1:1:1 to one of three sequences of antihypertensive treatment. Patients stop their regular antihypertensive medication for a 2-week run-in period followed by 4-week periods of monotherapy with amlodipine, losartan and atenolol in random order as open-label medication in standard dose.

Outcomes

The primary outcome measure is cerebrovascular reactivity (CVR) as determined by blood oxygen level dependent brain MRI signal response to hypercapnic challenge with change in CVR in normal appearing white matter as primary endpoint. Secondary outcome measures are mean systolic blood pressure (BP) and BP variability (BPv).

Discussion

TREAT-SVDs will provide insights into the effects of different antihypertensive drugs on CVR, BP, and BPv in patients with symptomatic sporadic and hereditary SVDs.

Funding

European Union's Horizon 2020 programme.

Trial registration

NCT03082014.

Impact of ethnicity on adverse perinatal outcome in women with chronic hypertension: a cohort study

OBJECTIVE

To assess the impact of maternal ethnicity on the risk of adverse perinatal outcome in pregnant women with chronic hypertension.

METHODS

Demographic and delivery data were collated of women with chronic hypertension and singleton pregnancy who delivered at one of three UK obstetric units between 2000 and 2014. Multivariable logistic regression models were used to calculate risk ratios (RR), according to ethnic group, for adverse perinatal outcome, adjusted for other maternal characteristics including age, parity, body mass index, smoking status, deprivation index and year of delivery. The impact of maternal ethnicity on birth-weight centile calculation was investigated by comparing the birth-weight centile chart customized for ethnicity (Gestation Related Optimal Weight; GROW) with a birth-weight centile calculator that does not adjust for that factor (INTERGROWTH-21^st ).

RESULTS

The study cohort included 4481 pregnancies (4045 women) with chronic hypertension. Women of white ethnicity accounted for 47% (n = 2122) of the cohort and 36% (n = 1601) were of black, 8.5% (n = 379) of Asian and 8.5% (n = 379) of other ethnicity. The overall incidence of stillbirth was 1.6%, that of preterm birth < 37 weeks was 16% and that of fetal growth restriction (birth weight < 3^rd centile) was 11%. Black women, compared with white women, had the highest risk for all adverse perinatal outcomes, with stillbirth occurring in 3.1% vs 0.6% of pregnancies (adjusted RR (aRR), 5.56 (95% CI, 2.79-11.09)), preterm birth < 37 weeks in 21% vs 11% (aRR, 1.70 (95% CI, 1.43-2.01)) and birth weight < 3^rd centile in 15% vs 7.4% (aRR, 2.07 (95% CI, 1.71-2.51)). Asian women, compared with white women, were also at increased risk of adverse perinatal outcome, with stillbirth occurring in 1.6% vs 0.6% (aRR, 3.03 (95% CI, 1.11-8.28)), preterm birth < 37 weeks in 20% vs 11% (aRR, 1.82 (95% CI, 1.41-2.35)) and birth weight < 3^rd centile in 12% vs 7.4% (aRR, 1.69 (95% CI, 1.24-2.30)). The sensitivity and specificity for prediction of infants requiring neonatal unit admission were 40% and 93%, respectively, for those with birth weight < 3^rd centile according to GROW charts, compared with 16% and 96%, respectively, for those with birth weight < 3^rd centile according to INTERGROWTH-21^st charts.

CONCLUSIONS

Black ethnicity, compared with white, is associated with the greatest risk of adverse perinatal outcome in women with chronic hypertension, even after adjusting for other maternal characteristics. Women of Asian ethnicity are also at increased risk, but to a lesser extent. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Therapeutic effects of inorganic nitrate and nitrite in cardiovascular and metabolic diseases

Nitric oxide (NO) is generated endogenously by NO synthases to regulate a number of physiological processes including cardiovascular and metabolic functions. A decrease in the production and bioavailability of NO is a hallmark of many major chronic diseases including hypertension, ischaemia-reperfusion injury, atherosclerosis and diabetes. This NO deficiency is mainly caused by dysfunctional NO synthases and increased scavenging of NO by the formation of reactive oxygen species. Inorganic nitrate and nitrite are emerging as substrates for in vivo NO synthase-independent formation of NO bioactivity. These anions are oxidation products of endogenous NO generation and are also present in the diet, with green leafy vegetables having a high nitrate content. The effects of nitrate and nitrite are diverse and include vasodilatation, improved endothelial function, enhanced mitochondrial efficiency and reduced generation of reactive oxygen species. Administration of nitrate or nitrite in animal models of cardiovascular disease shows promising results, and clinical trials are currently ongoing to investigate the therapeutic potential of nitrate and nitrite in hypertension, pulmonary hypertension, peripheral artery disease and myocardial infarction. In addition, the nutritional aspects of the nitrate-nitrite-NO pathway are interesting as diets suggested to protect against cardiovascular disease, such as the Mediterranean diet, are especially high in nitrate. Here, we discuss the potential therapeutic opportunities for nitrate and nitrite in prevention and treatment of cardiovascular and metabolic diseases.

The safety and efficacy of intracoronary nitrite infusion during acute myocardial infarction (NITRITE-AMI): study protocol of a randomised controlled trial

INTRODUCTION

Acute myocardial infarction (AMI) is a major cause of death and disability in the UK and worldwide. Presently, timely and effective reperfusion with primary percutaneous coronary intervention (PPCI) remains the most effective treatment strategy for limiting infarct size, preserving left ventricular ejection fraction (LVEF) and improving clinical outcomes. However, the process of reperfusion can itself induce cardiomyocyte death, known as myocardial reperfusion injury, for which there is currently no effective therapy. Extensive preclinical evidence exists to suggest that sodium nitrite (as a source of endogenous nitric oxide) is an effective therapeutic strategy for preventing myocardial reperfusion injury. The purpose of NITRITE-AMI is to test whether sodium nitrite reduces reperfusion injury and subsequent infarct size in patients undergoing PPCI for MI.

METHODS AND DESIGN

NITRITE-AMI is a double-blind, randomised, single-centre, placebo-controlled trial to determine whether intracoronary nitrite injection reduces infarct size in patients with myocardial infarction undergoing primary angioplasty. The study will enrol 80 patients presenting with ST-elevation myocardial infarction. Patients will be randomised to receive either a bolus of intracoronary sodium nitrite or placebo (sodium chloride) at the time of PPCI. The primary outcome is infarct size assessed by creatine kinase area under the curve (AUC) over 48 h. Secondary endpoints include troponin T AUC and infarct size, LV dimensions and myocardial salvage index assessed by cardiac MR (CMR), markers of platelet reactivity and inflammation, the safety and tolerability of intracoronary nitrite, and 1 year major adverse cardiac events.

ETHICS AND DISSEMINATION

The study is approved by the local ethics committee (NRES Committee London West London: 11/LO/1500) and by the Medicines and Healthcare Products Regulatory Agency (MHRA) (EudraCT nr. 2010-022460-12). The results of the trial will be published according to the CONSORT statement and will be presented at conferences and reported in peer-reviewed journals.

TRIAL REGISTRATION

United Kingdom Clinical Research Network (Study ID 12117), http://clinicaltrials.gov (NCT01584453) and Current Controlled Trials (ISRCTN:38736987).

Inorganic nitrate and the cardiovascular system

Fruit and vegetable-rich diets reduce blood pressure and risk of ischaemic stroke and ischaemic heart disease. While the cardioprotective effects of a fruit and vegetable-rich diet are unequivocal, the exact mechanisms of this effect remain uncertain. Recent evidence has highlighted the possibility that dietary nitrate, an inorganic anion found in large quantities in vegetables (particularly green leafy vegetables), may have a part to play. This beneficial activity lies in the processing in vivo of nitrate to nitrite and thence to the pleiotropic molecule nitric oxide. In this review, recent preclinical and clinical evidence identifying the mechanisms involved in nitrate bioactivity, and the evidence supporting the potential utility of exploitation of this pathway for the prevention and/or treatment of cardiovascular diseases are discussed.

Role for endothelial nitric oxide synthase in nitrite-induced protection against renal ischemia-reperfusion injury in mice

Nitrite is protective against renal ischemia/reperfusion injury (IRI); an effect due to its reduction to nitric oxide (NO). In addition to other reductase pathways, endothelial NO synthase (eNOS) may also facilitate nitrite reduction in ischemic environments. We investigated the role of eNOS in sodium nitrite (60 microM, 10 ml/kg applied topically 1 min before reperfusion)-induced protection against renal IRI in C57/BL6 wild-type (WT) and eNOS knockout (eNOS KO) mice subjected to bilateral renal ischemia (30 min) and reperfusion (24h). Markers of renal dysfunction (plasma [creatinine] and [urea]), damage (tubular histology) and inflammation (cell recruitment) were elevated following IRI in WT mice; effects significantly reduced following nitrite treatment. Chemiluminescence analysis of cortical and medullary sections of the kidney demonstrated rapid (within 1 min) distribution of nitrite following application. Whilst IRI caused a significant (albeit substantially reduced compared to WT mice) elevation of markers of renal dysfunction and damage in eNOS KO mice, the beneficial effects of nitrite were absent or reduced, respectively. Moreover, nitrite treatment enhanced renal dysfunction in the form of increased plasma [creatinine] in eNOS KO mice. Confirmation of nitrite reductase activity of eNOS was provided by demonstration of nitrite (100 microM)-derived NO production by kidney homogenates of WT mice, that was significantly reduced by L-NMMA. L-NMMA was without effect using kidney homogenates of eNOS KO mice. These results support a role for eNOS in the pathways activated during renal IRI and also identify eNOS as a nitrite reductase in ischemic conditions; activity which in part underlies the protective effects of nitrite.

Parentage identification using single nucleotide polymorphism genotypes: application to product tracing

Identification of relatives using SNP markers has many possible applications. One is as a route to tracing a food product such as a cut of meat back to its source of origin by identifying the parents of the animal from which the product was derived. We develop methods for using SNP markers with maximum likelihood, allowing for the possibility of genotyping errors that would cause false exclusions by simpler methods. We use expectations of likelihood ratios to consider how gene frequencies in the parental populations, numbers of loci, and error rates affect accuracy. This is further quantified as the risk, the probability that an incorrect sire is identified from a panel that contains many other putative sires including its relatives, using a breeding structure relevant to pig breeding. This appears to be a straightforward and potentially effective means of product tracing.

Parotid Warthin's tumour Bristol Royal Infirmary (1985-1995): a study of histopathology in 33 cases

This is a study of 33 (32 patients) confirmed Warthin's tumours (adenolymphomas) treated surgically at Bristol Royal Infirmary (1985--1995) focussing specifically upon 17 salient histopathological features together with capsular measurement by micrometry. Twenty-four out of 33 tumours had 'thin' capsules (< or = 200 microm), whereas 5/9 'thick' capsules were associated with gross tumour degeneration. The degenerative features including cystic change, squamous metaplasia, corpora amylacea like bodies, etc. were quantified. Tumours were classified into subtypes (typical, stroma poor, etc). These variations were not associated with age or sex. In 20/33 tumours a marginal sinus suggested a lymph node origin. Fine needle aspiration cytology (FNA) smears showing degeneration features are a diagnostic problem, but histopathological features are reflected in such smears and their recognition enhances diagnostic precision, enabling controlled surgical enucleation, the ideal operation, to be performed in most cases. In this study only 12 tumours were so treated; 11 others received parotidectomy. The theories of histogenesis are reviewed and discussed.

Reactions from the medical and nursing professions to Nightingale's "reform(s)" of nurse training in the late 19th century

In 1860, the Nightingale School of Nursing opened at St Thomas's Hospital, London. Florence Nightingale's overriding raison d'etre in the setting up of this foundation was a replacement of the old fashioned nurse (caricatured by Mrs Gamp-an "ignorant and immoral drunkard") by the highly trained, and eminently respectable "lady-nurse". While this change met with a great deal of approval from the lay public and the majority of the nursing profession, a minority of the latter together with the bulk of medical practitioners (including several leading physicians and surgeons of the day) wholeheartedly opposed this revolutionary move. It was felt, by them, that the medical profession was in danger of losing control over nursing with the resultant sacrifice of satisfactory patient care. Today, both medical student and nurse training is moving noticeably away from the bedside, an orientation which has added such an important dimension to British medical/nurse training over so many generations. Is this 19th century experience yet another example of history repeating itself in the medical sphere?

The Albert Dock Hospital, London: the original site (in 1899) of Tropical Medicine as a new discipline

The London School of Tropical Medicine, and indeed the 'new' discipline of tropical medicine, originated in 1899 at the Albert Dock Hospital - situated in London's east-end. The founder of the discipline was Patrick Manson - with a great deal of political assistance from the British Secretary of State for the Colonies (Joseph Chamberlain). The hospital (originally opened in 1890) was rebuilt in 1937-1938 and ultimately demolished in 1993.

Pleomorphic adenomas of the major salivary glands: a study of the capsular form in relation to surgical management

This was a retrospective study of 126 primary pleomorphic adenomas to correlate capsular characteristics with tumour histopathology in relation to current surgical debate (parotidectomy versus local excision). Capsular thickness was measured by micrometry and tumours classified into subtypes (1-4). Evidence of fine needle aspiration damage (needle tracks, infarction) was sought. Minimal changes were seen in eight tumours. Tumour growth features (bosselations, enveloping) were present in 57% and 33%, respectively, also microinvasion (42%) and tumour 'buds' (12%). Parotid lesions possessed thicker capsules than submandibular tumours. There was little correlation between capsular thickness and cellular structure. The significant exception was large (> 25 mm) hypocellular parotid tumours which had thinner capsules and could be vulnerable to operative rupture. In 110 standard operations (parotidectomy, submandibular gland excision), capsular exposure was evident in 81%. Field irrigation is recommended to lessen the risk of tumour seeding. This study reaffirms many elements of capsular weakness and suggests that parotidectomy is the operation of choice.

Improving cytological diagnosis and surgical management of parotid adenolymphoma

BACKGROUND

The role of fine-needle aspiration cytology (FNAC) in the diagnosis and management of discrete parotid swellings remains controversial. Controlled enucleation can be appropriate with accurate preoperative diagnosis. This study (1985-1995) reviewed the role of FNAC in the diagnosis and surgical management of adenolymphoma.

METHODS

Review of cytological smears by two observers concentrated on the features of infarction and squamoid metaplasia. Sensitivity, interobserver and intraobserver variation were evaluated statistically in a two-run 'blinded' analysis of 80 cytological slides from a variety of lesions.

RESULTS

Of 222 epithelial neoplasms of the parotid, 33 were adenolymphomas. FNAC was performed before operation in 32, producing 34 slides, and a correct cytological diagnosis was made in 21 patients. Retrospective review of the 34 slides, to examine specific features of squamoid metaplasia and infarction, improved diagnostic accuracy. The reliability and reproducibility of cytodiagnosis was confirmed by analysis of interobserver and intraobserver agreement. The sensitivity was high (0.76-0.88). Controlled enucleation was performed in 12 patients and superficial parotidectomy in 11. There were no tumour recurrences.

CONCLUSION

Attention to the features of squamoid metaplasia and infarction improves cytological diagnosis and directs appropriate surgical management.

Objectives and strategies in pig improvement: an applied perspective

Largely because of the influence of Charles Smith, simple performance testing of pigs over the previous 30 yr has been highly successful. With larger production units, current genetic objectives can be divided into two components: 1) to raise genetic potential for production traits and 2) to maximize the probability that this potential can be realized in practice. Faster improvement through increased accuracy and a more flexible nucleus structure are offered by BLUP methodology. Electronic measures of feed intake permit selection based on feeding behavior and the shape of the feed intake curve. After the elimination of the halothane gene, the next limiting factor for meat quality could be intramuscular fat. With more than 1500 mapped genes, the main constraints on marker-assisted selection are the high costs of DNA testing and the relatively small effects of this selection on performance. A combination of the possible effects of BLUP, the Meishan breed, and the ESR gene could give genetic improvements totaling 4 liveborn piglets per litter over the next 10 yr. There appear to be no limits on future improvement of lean growth, but risks are adverse changes in reproduction and disease resistance. Existing quantitative methods of improvement are very cost effective. The greatest challenge for molecular technologies may be the genetics of the immune system.

The lateral thyroid ligament of Berry

Division of the lateral thyroid ligament is essential for total thyroid lobectomy. The exact extent of this ligament, first described by Berry in 1888, was studied in a series of 25 cadaveric and post-mortem subjects. The ligament was attached to the inferior margin of the cornu of the cricoid cartilage, near its pole, and extended infero-medially onto the tracheal wall, reaching the midline in 4 of the 50 lobes examined. At the level of the cricoid cartilage, the mean distance between the attachment of the ligament to the cricoid cartilage and the recurrent laryngeal nerve (RLN) entry point into the larynx was 1.9 mm. This region corresponds to the area where RLNs are mostly injured during thyroid surgery. Awareness of the extent of this ligament and the proximity of the RLN to it should lessen the risk of injury to the RLN during thyroid lobectomy and total thyroidectomy.

A comparative audit of prevalent, incident and interval cancers in the Avon breast screening programme

The 4th year of the Avon breast screening programme comprises two distinct groups: those called for screening for the first time (prevalent group) and those who were initially screened 3 years earlier (incident group). The cancer detection rate, stage of disease and rate of interval cancers in these patients have been compared. For the prevalent groups of year 1 and year 4 there was no statistically significant difference in the cancer detection rate, proportion of small tumours or node positivity. For the prevalent and incident groups of year 4, there was no statistically significant difference in the cancer detection rate or proportion of small tumours. There were significantly fewer node-positive tumours in the incident group (5/45 vs 8/23; P < 0.05). Fifty-six interval cancers presented in the 3-year period between years 1 and 4 of screening; 28 (50%) after 24 months. The screening programme may result in tumours being detected at an earlier stage, but this may be offset by the high rate of interval cancers. This suggests that the time between screens may need to be reduced to 2 years.

Rate and classification of interval cancers in the breast screening programme

There has been concern about the number of interval cancers which have been detected within the National Breast Screening Programme. A series of 134 women presenting with interval cancers was studied by prospective audit and the rate and radiological classification of the tumours determined. The cancers were classified as true (67), false-negative (22), unclassifiable (28), occult (12), and minimal sign (5). The interval cancer rate did not achieve the new National Guidelines in either the first 2 years or the 3rd interval year. The false-negative cancers presented mainly in the 1st interval year, whereas the true cancers were predominantly confined to the 2nd and 3rd years. These data suggest that alterations to the screening programme may be beneficial. It may be, however, that the programme is still on the learning curve and this should be taken into account when interpreting these data.

Problems in diagnosis and management of goitre in childhood and adolescence

This study is a retrospective review of 17 patients aged 16 and under with a total of 18 goitres, who were investigated and treated at Bristol Children's Hospital and Bristol Royal Infirmary between 1967 and 1994. There were five neoplasms, comprising follicular adenoma (three) and papillary carcinoma (two). Other benign causes of goitre included nodular goitre (four), non-toxic hyperplasia (three) and chronic lymphocytic thyroiditis (three). The authors suggest some guidelines to help in the diagnosis and management of goitre in young patients, as a consequence of significant difficulties encountered in 12 of the 17 patients in this series.

The treacherous fibroadenoma: a 'mighty mouse'

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Exfoliative cytology in the diagnosis of breast disease

A total of 393 nipple discharge or scrape smears from 360 women were examined cytologically over a 12-year period. Twenty-nine breast cancers (8 per cent) have been histologically confirmed in this group, of which 16 had malignant smear cytology (sensitivity 55 per cent). Nine patients with breast cancer and positive cytology had impalpable tumours. Two of these cancers were not detected by any other investigation. Thirteen patients with nipple discharge had false-negative cytology, but there were no false-positive results (specificity 100 per cent). All patients with expressible or spontaneous nipple discharges and those with skin changes at the nipple should undergo examination of cytological smears.

Scrape cytology in the diagnosis of Paget's disease of the breast

Eczema of the nipple is an important symptom presenting to the general surgeon in the out-patient department. The diagnosis of Paget's disease of the nipple has traditionally been made by incision biopsy necessitating at least a local anaesthetic. We present 14 patients with nipple skin change, in whom the technique of scrape cytology was used to identify patients with Paget's disease. In our series eight cases of Paget's disease were successfully identified by scrape cytology with no false negatives or positives. We suggest that this is a quick, easy, non-invasive method of screening eczema of the nipple in the out-patient clinic.

Prolonged remission of hypercalcaemia due to parathyroid carcinoma with pamidronate

Parathyroid carcinoma is rare and the associated hypercalcaemia is often resistant to all treatment. A case is described in which prolonged control of hypercalcaemia has been achieved by infrequent infusions of pamidronate despite continuing hypersecretion of parathyroid hormone.

Primary breast lymphoma with skin involvement arising in lymphocytic lobulitis

Primary breast lymphoma is a rare tumour which has recently been associated with pre-existing lymphocytic lobulitis. We report a patient with lymphocytic lobulitis in whom the lymphoma recurred in the contra-lateral breast 5 years after the initial presentation, to be followed shortly afterwards by skin involvement. This progression illustrates the relationship between extra-nodal lymphomas and underlying autoimmune disease and the homing of lymphomas to related sites.

Will screening for breast cancer reduce mortality? Evidence from the first year of screening in Avon

In the first year of screening in Avon, 93 malignant lesions were detected of which one-half were impalpable. Of the impalpable lesions, one-half were in situ or showed areas of microinvasion only. One-fifth of the malignant lesions were invasive tumours of special histological type which are known to carry a good prognosis even when not detected by screening. One-quarter of the lesions had clinical or pathological features which would be expected to confer a poor prognosis. Only 16 invasive ductal carcinomas measuring 1 cm or less in diameter were detected--a small proportion of the total number of malignant lesions. Although these early figures suggest that the effect of screening on mortality from breast cancer may be small, continued high-quality screening and careful detailed analysis are essential to determine the effect of screening on the mortality from breast cancer and the effect on the population as a whole.

Diagnostic and therapeutic aspects of fine-wire localization biopsy for impalpable breast cancer

During the first 2 years (July 1989 to July 1991) of the Avon Breast Screening Service, fine-wire localization biopsy was indicated in 213 impalpable breast lesions. A total of 144 lesions were benign and 69 malignant. Only four of 213 lesions (1.9 per cent) were not excised at the first localization. Factors influencing reoperation in the 69 patients with malignant impalpable lesions were examined. There was a significant association (P < 0.001) between parenchymal disturbances on mammography and invasive carcinoma, and between non-invasive carcinoma and microcalcification (P < 0.001). In 31 patients the localization biopsy was the only surgical procedure. Thirty-eight patients required further surgery: 12 underwent further local excision and 26 mastectomy. Reoperation was more frequent in patients with calcification than in those with parenchymal disturbance (P < 0.001). The most frequent indications for mastectomy were inadequate excision of widespread comedo ductal carcinoma in situ or invasive ductal carcinoma combined with extensive ductal carcinoma in situ. Fine-wire localization biopsy was a combined therapeutic and diagnostic procedure in 31 of 69 women with impalpable screen-detected lesions. The majority of patients required further surgery because radiological abnormalities underestimated the extent of disease.

Hepatic metastases in adenoid cystic carcinoma of the submandibular gland

We present a case of adenoid cystic carcinoma of the submandibular gland resulting in metastases to the liver, nine years following initial presentation.

Florid papillomatosis of the nipple: a clinico-pathological surgical problem

Adenoma or florid papillomatosis of the nipple is a rare, benign condition which resembles the clinical appearances of Paget's disease of the nipple and the histological appearances of papillary carcinoma of the breast. We describe a case which illustrates the pitfalls in diagnosis and proposes a safe management procedure for breast and nipple lesions.

The disposition of 2-cyano-1-methyl 3-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydro-pyridazin-3-yl)phenyl)guanidine in animals

2-Cyano-1-methyl 3-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydro-pyridazin-3-yl)phenyl)guan idine (SK&F 94836), a new positive inotrope/vasodilator, is being evaluated for the treatment of congestive heart failure. The absorption, metabolism, and disposition of the compound have been investigated in the rat, mouse, and dog. SK&F 94836 was rapidly absorbed, widely distributed, and rapidly and completely excreted primarily via the urine. There was no evidence of metabolism of the compound in any of the species studied. The compound showed minimal interaction with cytochrome P-450. The compound contains a chiral center. The enantiomers have been shown not to interconvert in either rat or dog. The serum protein binding was low in all species, including humans, and exhibited no stereoselectivity. Studies conducted in rat and dog using constant rate co-infusion of racemic SK&F 94836 and radiolabeled inulin have demonstrated that SK&F 94836 is eliminated by active tubular secretion.

Management of high grade parotid carcinomas

Thirty-four patients admitted to the Bristol Royal Infirmary during the 20-year period 1966-85 and diagnosed as suffering from high grade parotid carcinoma were studied. The male:female ratio was 2.4:1, with a mean age at presentation of 68 years. Facial swelling was present in all patients with a mean duration of 9.9 months before treatment. Pain, deep fixation, facial nerve involvement, ulceration and distal metastases were all associated with a poor prognosis. Diagnosis was made either at operation or by fine needle biopsy. All 34 patients received radiotherapy. Fourteen patients (41 per cent) underwent a definitive surgical procedure. The local recurrence rates for the non-surgical and surgically treated groups were 30 per cent (six patients) and 36 per cent (five patients) respectively; twelve patients (60 per cent) in the non-surgical group developed distant metastases as opposed to six patients (43 per cent) in the surgical group. Both local and distant recurrent disease are indicators of poor prognosis, with only one patient alive at 104 months. Seven patients (21 per cent) remain recurrence free. Definitive surgery, combined with radiotherapy, improved survival in those with amenable localized disease.

Supracondylar fractures of the humerus in children

Thirty-five children were evaluated at a mean of 2 years, 3 months following treatment of supracondylar fractures of the humerus. Elbow motion, clinical carrying angle, and roentgenographic measurements including Baumann's angle, humeral-ulnar angle, and metaphyseal-diaphyseal angle were determined for both the normal and the involved extremities. The humeral-ulnar angle best correlated with the final clinical carrying angle, followed by Baumann's angle and the metaphyseal-diaphyseal angle. We recommend postreduction measurement of the humeral-ulnar angle in fractures that have been surgically stabilized and Baumann's angle in those fractures treated by cast immobilization alone to determine the adequacy of reduction.

Beta-adrenergic responsiveness in stress-sensitive and stress-resistant pigs

This study investigated whether enhanced metabolic responsiveness to beta-adrenergic stimulation might explain the liability of the stress-sensitive pig to develop an acidosis during stressful situations. Blood lactate, pH, PCO2 and heart rate response to an intravenous infusion of isoprenaline were examined in three lines of pentobarbitone anaesthetized, atropinized pigs. The lines were Pietrain X Hampshire which had been selected over eight generations for a positive reaction to the halothane test (stress-sensitive); Pietrain X Hampshire which had been selected over eight generations for no reaction to the halothane test (stress-resistant) and British Landrace which had been selected over four generations for a positive halothane reaction (stress-sensitive). The metabolic responses to isoprenaline were greater in the stress-sensitive Pietrain X Hampshire line than the stress-resistant line. The stress-sensitive Landrace pigs, however, had smaller changes in pH and PCO2 in response to isoprenaline than the stress-resistant Pietrain X Hampshire pigs. This inconsistent trend across the three lines led to the conclusion that enhanced beta-adrenergic responsiveness was not the likely cause of stress sensitivity.

Triggering of B lymphocytes through CD23: epitope mapping and studies using antibody derivatives indicate an allosteric mechanism of signalling

By using five monoclonal antibodies in reciprocal cross-locking studies, a minimum of three epitope clusters have been defined for the B-cell restricted, activation-associated CD23 antigen. Two of the five antibodies were capable of replacing low molecular weight B-cell growth factor (BCGF) in B-cell co-stimulation assays. These two antibodies belonged to the same epitope group, while non-stimulatory antibodies fell outside this cluster. By prior coating of activated B lymphocytes at 4 degrees, all five CD23 antibodies interfered with the subsequent uptake of BCGF activity onto the cells. However, only the two stimulatory antibodies were capable of inhibiting the absorption of BCGF completely. From one of these antibodies, F(ab')2 and Fab fragments were generated and both were found to be equivalent to whole antibody in their ability to mimic BCGF. Immobilized antibody, however, failed to stimulate over a wide range of concentrations. These findings demonstrate that the ability of certain CD23 antibodies to deliver a growth-promoting signal to activated B cells is independent not only of the Fc portion of the molecule but also of receptor cross-linking. The latter observation is indicative of an allosteric mechanism of triggering, a notion supported by the epitope specificity of activation through CD23. The findings are discussed in relation to the putative natural ligands for CD23 and the way they may influence B-cell function through this receptor.

Fine-needle aspiration biopsy and the diagnosis of thyroid cancer

Conventional criteria for the evaluation of thyroid nodules are inaccurate in identifying the small proportion of malignant neoplasms. The diagnostic accuracy of fine-needle aspiration biopsy (FNAB) for cytology was therefore assessed in 562 patients with nodular thyroid disease, 373 of whom (66.4 per cent) had histological confirmation of the cytological diagnosis. Sixty-one aspiration biopsies were positive for malignancy, and the diagnosis was confirmed histologically in 59 of these (96.7 per cent). Thus, there were two false positive cytology results among 310 patients with proven benign disease (0.6 per cent). Four of sixty-three patients with proven carcinoma had a benign cytological diagnosis, a false negative rate of 6.3 per cent. In 57 of the 59 malignancies (96.6 per cent) correctly diagnosed by FNAB the histological type of tumour was successfully identified. Overall 367 of 373 patients received correct cytological discrimination between benign and malignant nodules, an overall accuracy of 98.4 per cent for FNAB. The sensitivity of the test was 93.7 per cent and the specificity 99.4 per cent. Besides being safe, cost-effective and reliable, FNAB directs the appropriate selection of patients for surgery and enables the correct operation to be performed for each type of tumour.

Evidence for an association between CD23 and the receptor for a low molecular weight B cell growth factor

Low molecular weight B cell growth factor (BCGF) and a monoclonal antibody (MHM6) to the 45-kDa, B lineage-restricted, CD23 activation antigen (BLAST-2; EBVCS) were found to be indistinguishable in their biological effects. Individually, both augmented DNA synthesis in activated, but not resting, B lymphocytes while no additional enhancement resulted from using the two agonists in combination. Furthermore, by increasing the expression of Tac, both MHM6 and BCGF promoted activated B cells to respond more vigorously to the late addition of recombinant interleukin 2. The presence of BCGF during B cell activations was found to down-regulate the expression of the CD23 antigen while the coating of activated cells with MHM6 antibody diminished their capacity to absorb BCGF activity. The findings demonstrate that CD23 and a low molecular weight BCGF deliver a comparable growth-promoting signal to activated B cells. A possible relationship between CD23 and the receptor for the low molecular weight BCGF is discussed.

Adenolymphoma of the parotid: aetiology, diagnosis and treatment

In order to study the changing clinical pattern, diagnosis and surgical treatment of adenolymphoma, the records of all 57 patients with a confirmed histological diagnosis, made at Bristol Royal Infirmary between 1951 and 1984, were reviewed; in 3 patients (5 per cent) bilateral lesions had been found. No characteristics emerged in a review of the history and clinical examination which would have enabled a correct preoperative diagnosis to be made. During the period of study the incidence of adenolymphoma increased 24-fold. (Parotid pleomorphic salivary adenomas increased in incidence by only 42 per cent over the same period). Before 1965 all patients were men; between 1965 and 1975 the male to female ratio was 3:1; between 1975 and 1985, 1.6:1. Of the 48 patients who had a relevant history taken 45 were smokers (93.8 per cent). It is postulated that tobacco consumption is important in the development of adenolymphoma, and has produced the changes in incidence and sex ratio. Fine needle aspiration biopsy cytology (FNAB) afforded the only method of achieving a pre-operative diagnosis. This was successful in 64.7 per cent. Superficial parotidectomy induced a 43 per cent incidence of facial nerve neurapraxia. Controlled enucleation reduced this to 8 per cent. Enucleation is the procedure of choice for adenolymphoma but can only be employed with confidence if an exact pre-operative diagnosis is made.

Does radiolabelled diphosphonate retention reflect bone metabolism in the elderly?

The 24-h whole-body retention of diphosphonates (WBR), a useful measure of bone metabolism in young subjects, was measured in 27 elderly subjects (19 from home and eight in-patients). WBR rose with increasing age (r = 0.55, P less than 0.01) and was negatively correlated with renal function (r = -0.60, P less than 0.01). In five subjects given vitamin D, WBR did not fall. The measurement of WBR in the elderly has to be assessed in the light of an accurate assessment of renal function and so is rarely clinically useful.