A monoclonal antibody-based sandwich ELISA for measuring canine Thymidine kinase 1 protein and its role as biomarker in canine lymphoma

Introduction

Dogs play an important role in society, which increased during the covid epidemics. This has led to a much higher workload for the veterinarians. Therefore, there is a need for efficient diagnostic tools to identify risk of malignant diseases. Here the development of a new test that can solve some of these problems is presented. It is based on serum Thymidine Kinase 1 (TK1), which is a biomarker for cell proliferation and cell lysis.

Methods

Anti-TK1 monoclonal antibodies were produced against two different epitopes, the active site of the TK1 protein and the C-terminal region of canine TK1. The antibodies were developed with hybridoma technology and validated using dot blot, Quartz Crystal Microbalance (QCM) technology, western blots, immunoprecipitation (IP), and enzyme-linked immunosorbent assay (ELISA). Clinical evaluation of Canine TK1 ELISA was done by using sera from 131 healthy dogs and 93 dogs with lymphoma. The two selected Anti-TK1 monoclonal antibodies have Kd values in the range of 10-9 M and further analysis with dot and western blots confirmed the high affinity binding of these antibodies. A sandwich Canine TK1 ELISA was developed using the anti-TK1 antibodies, and TK1 concentrations in serum samples were determined using dog recombinant TK1 as a standard.

Results

Serum TK1 protein levels were significantly higher in dogs with lymphoma compared to those in healthy dogs (p < 0.0001). Receiver operating curve analysis showed that the canine TK1-ELISA obtain a sensitivity of 0.80, at a specificity of 0.95. Moreover, the Canine TK1 ELISA has a positive predictive value (PPV) of 97%, and the negative predictive value (NPV) of 83%, reflecting the proportion of test results that are truly positive and negative. Furthermore, Canine TK1 ELISA had significantly higher capacity to differentiate dogs with T-cell lymphoma from those with B-cell lymphoma compared to earlier used TK1 activity assays.

Discussion

These results demonstrate that the Canine TK1 ELISA can serve as an efficient tool in the diagnosis and management of dogs with lymphomas.

Molecular characterization of equine thymidine kinase 1 and preliminary evaluation of its suitability as a serum biomarker for equine lymphoma

Background

Thymidine kinase 1 (TK1) plays a key role in the synthesis of deoxythymidine triphosphate (dTTP) and is thus important for DNA replication and cell proliferation. The expression of TK1 is highest during S-phase, and it is rapidly degraded after mitosis. In cancer cells, TK1 is upregulated, resulting in leakage of excess TK1 into the blood. Consequently, serum TK1 has been used as a diagnostic and prognostic cancer biomarker, mainly in human medicine. The aims of this work were to characterize equine TK1 and to evaluate its suitability as a serum biomarker for equine lymphoma.

Results

Equine TK1 was cloned, expressed in E. coli and affinity purified. The purified recombinant horse TK1 showed broad substrate specificity, phosphorylating pyrimidine deoxyribo- and ribonucleosides and, to some extent, purine deoxynucleosides, including anticancer and antiviral nucleoside analogues. ATP was the preferred phosphate donor. Serum TK1 activity was measured in samples collected from horses with confirmed or suspected lymphoma and control horses with and without concurrent diseases. Serum TK1 activity levels were significantly higher in horses with lymphoma (p <  0.0005) and suspected lymphoma (p <  0.02) and in tumour-free groups with diverse diseases (p <  0.03) than in controls without concurrent diseases. There was a significant difference between the lymphoma group and the tumour-free group with diverse diseases (p <  0.0006). Furthermore, receiver operating characteristic analysis revealed a sensitivity of 0.86, a specificity of 0.95 and an AUC (area under the curve) of 0.92 compared to the controls without concurrent diseases, with a sensitivity of 0.97, a specificity of 0.71 and an AUC of 0.88 when compared with the tumour-free group with diverse diseases.

Conclusion

Equine TK1 showed high specific activity and broader substrate specificity than human TK1. Anticancer and antiviral thymidine analogues were efficiently phosphorylated by horse TK1, suggesting that these analogues might be good candidates for chemotherapy in horses. Serum TK1 activity was significantly higher in horses with lymphoma than in controls. ROC analysis indicated that serum TK1 could serve as a promising cancer biomarker in horses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-021-00399-x.

Feline thymidine kinase 1: molecular characterization and evaluation of its serum form as a diagnostic biomarker

BACKGROUND

Thymidine kinase 1 (TK1) catalyzes the initial phosphorylation of thymidine in the salvage pathway synthesis of dTTP, an essential building block of DNA. TK1 is a cytosolic enzyme with its highest level during the S-phase of the cell cycle. In cancer cells TK1 is upregulated and excess TK1 is leaked into the blood. Therefore, serum TK1 has been used as biomarker for cancer diagnosis and prognosis in human medicine. Feline TK1 shows high sequence similarity to TK1 from other species. The aim of this study was to characterize feline TK1 and evaluate if serum TK1 can be used as a diagnostic biomarker.

RESULTS

Feline TK1 was cloned, expressed and affinity purified. The purified feline TK1 phosphorylated not only pyrimidine deoxyribonucleosides but also pyrimidine ribonucleosides and to some extent purine deoxynucleosides. A number of anticancer and antiviral nucleoside analogs also served as substrates with fairly high efficiency. ATP and dATP were the preferred phosphate donor. Serum TK1 activity in felines with malignant diseases was significantly higher than that in healthy individuals. ROC analysis revealed an area under the curve (AUC) of 0.98 with a sensitivity of 0.83 and a specificity of 0.95 for felines with lymphoma. Serum TK1 activity in felines with IBD or inflammatory disease was within the same range as healthy ones. Furthermore, in felines with lymphoma serum TK1 activity returned to normal levels in response to treatment.

CONCLUSION

Feline TK1 has high specific activity and a broader substrate specificity in comparison with TK1 from other species. Serum TK1 activity in felines with malignant diseases is significantly higher than that in normal felines and in felines with inflammatory diseases. These results suggest that serum TK1 may be a promising biomarker for the diagnosis and monitoring of malignant diseases and for the differential diagnosis of certain inflammatory disease.

Cardiac failure, transplantation and donation: current perspectives

Cardiac failure remains a significant source of morbidity and mortality worldwide. Multiple treatment options exist and have variable safety and reliability. Stem cell grafting and left ventricular assist device implantation are two of the promising recent techniques that have a bright future as transient and permanent therapies for end-stage heart failure. For the moment though they serve largely as bridges to cardiac transplantation, the definitive management of the failing heart. Cardiac transplantation itself is facing a number of challenges that limit its widespread usage globally. This review aims to obtain current perspectives on heart failure treatment, particularly among the three abovementioned modalities, whilst highlighting briefly some of the other novel treatment alternatives emerging globally. A comprehensive review of literature is undertaken from the past few years to understand the recent advancements, knowledge and research trends in this arena. An attempt is also made to understand the factors limiting the employment of modern management principles in the treatment of heart failure in the developing world, with particular emphasis on cardiac donation and transplantation; and the steps that could be taken to improve the desperately low recipient to donor ratio across the globe.

High levels of inactive thymidine kinase 1 polypeptide detected in sera from dogs with solid tumours by immunoaffinity methods: implications for in vitro diagnostics

Determination of serum thymidine kinase 1 (STK1) activity has been used as a proliferation marker for neoplastic diseases in both human and veterinary medicine. The purpose of this study was to determine STK1 activity and enzyme levels in different dog tumours. Serum samples from three dogs with leukaemia, five with lymphoma, 21 with solid tumours and 18 healthy dogs were analyzed for STK1 activity, using an optimized [(3)H]-deoxythymidine (dThd) phosphorylation assay, and for STK1 protein levels using an immunoaffinity/western blot assay. STK1 activity in dogs with haematological tumours was significantly higher than in the solid tumour and healthy dog groups (mean ± standard deviation [SD] = 65 ± 79, 1.1 ± 0.5, and 1.0 ± 0.4 pmol/min/mL, respectively). Serum samples were analyzed after immunoaffinity isolation by western blot and the TK1 26 kDa band intensities quantified revealing that concentrations were significantly higher in dogs with haematological tumours and solid tumours compared to healthy dogs (mean ± SD=33 ± 12, 30 ± 13, and 10 ± 5 ng/mL, respectively). Pre-incubation with the reducing agent dithioerythritol (DTE) showed a decrease in STK1 activity and protein levels in most samples, but an increase of about 20% in sera from healthy dogs and from those with haematological malignancies. Compared to animals with solid tumours, the specific STK1 activity (nmol [(3)H]-deoxythymidine monophosphate (dTMP)/min/mg of TK1 protein of 26 kDa) was 30-fold higher in haematological malignancies and 2.5-fold higher in healthy dogs, respectively. The results demonstrate that there is a large fraction of inactive TK1 protein, particularly in sera from dogs with solid tumours. The findings are important in the use of STK1 as a biomarker.

A sensitive and kinetically defined radiochemical assay for canine and human serum thymidine kinase 1 (TK1) to monitor canine malignant lymphoma

Thymidine kinase 1 (TK1) is a cell cycle regulated enzyme with maximum expression during the S phase. Serum TK1 (S-TK1) is a unique biomarker for cell proliferation. Here, an optimized [(3)H]-thymidine (dThd) phosphorylation assay is described, which is as sensitive as the commercially available TK-REA and TK-Liaison assays for measurement of S-TK1 activity in dogs and humans. Serum samples from dogs (35 healthy, 32 with lymphoma, 2 with leukemia, and 35 with solid tumors) and humans (18 healthy, 9 with chronic lymphocytic leukemia, 10 with myelodysplastic syndrome) were analyzed using the [(3)H]-dThd assay. Mean S-TK1 activities were 1.11 ± 0.46 pmol/min/mL in healthy dogs and 1.15 ± 0.32 pmol/min/mL in healthy humans. S-TK1 activities in dogs with hematological malignancies were 24.2 ± 47.9 pmol/min/mL, and the receiver operating characteristic curve showed an area under the curve of 0.88. With a cut-off value of 1.9 pmol/min/mL (mean value ± 2 SD), the sensitivity was 0.94 and the specificity was 0.68. Very similar results were obtained with human samples (healthy and lymphoma cases). S-TK1 activities measured during chemotherapy of six dogs with lymphoma were drastically reduced. In one case, S-TK1 activity increased prior to relapse. S-TK1 levels in dogs with solid tumors did not differ from the healthy group. S-TK1 activities correlated with those determined with the TK-REA and TK-Liaison assays (r=0.92 and r=0.96, respectively). In conclusion, this optimized [(3)H]-dThd assay is fast, sensitive and economical for measuring S-TK1 activity and should increase its clinical use as biomarker.

Risk of thyroid cancer after exposure to fertility drugs: results from a large Danish cohort study

BACKGROUND

Findings from the few epidemiological studies that have investigated thyroid cancer risk after fertility drugs have been inconclusive. Using data from the largest cohort of infertile women to date, we examined the effects of fertility drugs on thyroid cancer risk.

METHODS

A cohort of 54 362 women with infertility problems referred to Danish fertility clinics in the period 1963-1998 was established. A detailed data collection including information about type and amount of treatment was conducted. Using case-cohort techniques, we calculated rate ratios (RRs) of thyroid cancer associated with different fertility drugs after adjustment for age at first live birth.

RESULTS

A total of 29 thyroid cancers were identified during follow-up through 2000. Use of clomiphene [RR = 2.28; 95% confidence interval (CI): 1.08-4.82] or progesterone (RR = 10.14; 95% CI: 1.93-53.33) was associated with an increased thyroid cancer risk, although the latter estimate was based on few cases. When stratifying for parity status, the risk was primarily associated with clomiphene (RR = 3.09; 95% CI: 1.21-7.88) in parous women. No significantly increased risk was found after use of gonadotrophins, hCG or GnRH. We observed no association with number of cycles of use or years since first use (latency).

CONCLUSIONS

Clomiphene and possibly progesterone may increase thyroid cancer risk, particularly among parous women. Longer follow-up is needed to confirm our findings.

Diaminoindanes as microsomal triglyceride transfer protein inhibitors

The synthesis and biological activities of biarylamide-substituted diaminoindanes as microsomal triglyceride transfer protein (MTP) inhibitors are described. One of the more potent compounds, 8aR, inhibited both the secretion of apoB from Hep G2 cells and the MTP-mediated transfer of triglycerides between synthetic acceptor and donor liposomes with IC(50) values of 0.7 and 70 nM, respectively. In normolipidemic rats and dogs, oral administration of 8aR dose-dependently reduced both plasma triglycerides and total cholesterol. Moreover, in rats and dogs, 8aR also prevented the postprandial rise in plasma triglycerides following a bolus administration of a fat load. Because MTP inhibitors decrease very low density lipoprotein assembly in the liver, the potential for hepatic lipid accumulation was evaluated. In normolipidemic rats, hepatic cholesterol and triglyceride contents were dose-dependently increased by 8aR. However, hepatic lipid accumulation resulted in negligible change in total liver weight and was reversible after withdrawal of the compound.

Exposure of human vascular smooth muscle cells to Raf-1 antisense oligodeoxynucleotides: cellular responses and pharmacodynamic implications

To characterize the pharmacodynamic properties of CGP 69846A/ISIS 5132, an antisense oligodeoxynucleotide directed against the mitogenic signal transducer Raf-1 kinase, we investigated the elicited biological responses in human coronary artery smooth muscle cells. Cell exposure to CGP 69846A resulted in a reversible time- and concentration-dependent down-regulation of cellular Raf-1 gene expression and, ultimately, inhibition of cell cycle progression. The highest potencies of this compound to reduce Raf-1 mRNA and protein levels were observed after 24 and 48 hr of cell exposure, respectively, with corresponding IC50 values of approximately 100 and approximately 300 nM. Proliferation was inhibited with an IC50 value of approximately 300 nM after 72 hr. We interpreted the recovery rate of Raf-1 mRNA after cell exposure to antisense ODNs as the half-life (t1/2 approximately 50 hr) of active intracellular CGP 69846A in our cell culture system. The endogenous Raf-1 turnover half-life of approximately 30 hr, as assessed by monitoring metabolically labeled Raf-1 protein, correlated kinetically with the antisense-induced protein decay rate (50% decay in approximately 33 hr), indicating that the efficiency of CGP 69846A in decreasing Raf-1 protein levels was rate-limited by the endogenous protein turnover rate. The pharmacodynamic effects of CGP 69846A antisense ODNs are therefore limited by the duration of its intracellular activity rather than by its ability to transiently decrease mRNA levels. Local steady state exposure to CGP 69846A may represent a new approach to prevent the transition of quiescent vascular smooth muscle cells into the pathologically hyperproliferating cells seen after angioplasty.

Molecular and cellular characterization of baboon C-Raf as a target for antiproliferative effects of antisense oligonucleotides

C-Raf is a an essential member of the growth factor-ras pathway and a target for intervention strategies aimed at blocking cell proliferative responses. Excessive smooth muscle proliferation is considered one cause of the arterial closure in restenosis. Because of the similarity to the human cardiovascular system, a useful current animal model of the disease is a baboon model. As a foundation for animal studies employing antisense oligonucleotides, efforts were made to characterize the molecular and cellular biology of the baboon system. The nucleotide sequence of baboon c-raf cDNA was determined. Antisense phosphorothioate oligonucleotides specific to the 3'-UTR of c-raf mRNA from human and baboon were compared using primary baboon smooth muscle cells in culture. A particular human antisense oligonucleotide, referred to as ISIS 5132, was different by only 2 of 20 bases from the baboon sequence. The corresponding baboon antisense oligonucleotide ISIS 12959, however, was markedly more effective to inhibit c-raf mRNA, protein production, and DNA synthesis, and the results attest to the species specificity of the approach. After antisense treatment, c-raf mRNA levels dropped rapidly, whereas protein levels decreased with a half-life of roughly 24-48 hours, consistent with the antiproliferative effects. The data are discussed with regard to the profile of protein-protein interactions made by C-Raf and with the view that the baboon system closely parallels the human one at the signal transduction level. As this work progressed, a baboon cDNA homolog of a human c-raf-2 pseudogene was isolated, sequenced, and shown to be transcribed into mRNA.

The management of stab wounds to the chest: sixteen years' experience

In a retrospective review of 16 years of admissions to a regional cardiothoracic unit, 76 patients were admitted with stab wounds to the chest. Of these wounds, 75% were managed conservatively with tube drainage and observation and 25% required surgical intervention. 5.2% were managed as emergency room thoracotomies, 15.8% as urgent procedures in the operating theatre and 4% as late procedures. The total mortality was 1.3% and was seen in the emergency room thoracotomy group (mortality 25%). The risk if sub-diaphragmatic injury in the presence of chest injury is highlighted.

Valve replacement with the ATS open pivot bileaflet prosthesis

OBJECTIVE

We sought to evaluate the ATS open pivot bileaflet valve with respect to haemodynamics and thromboembolism.

METHODS

We prospectively studied 200 consecutive patients aged 13-80 years. One hundred and nineteen aortic, 103 mitral and 11 tricuspid valves were replaced in 172 single, 23 double and 5 triple valve procedures. Thirty-eight were re-operations and 51 underwent coronary bypass. Transvalvular gradients were determined by transoesophageal and transthoracic echocardiography. Patients were followed for 12 months to 3 years.

RESULTS

There were four hospital (2%) and three late deaths, each non-valve related. Two patients were reoperated for partial valve dehiscence. One aortic reoperation patient suffered a potential transient thromboembolic event. One tricuspid prosthesis thrombosed after anticoagulation was discontinued but thrombolysis resolved this problem. There were no other thromboembolic events. Valve gradients were equivalent or better than those for other bileaflet valves.

CONCLUSIONS

The ATS valve has excellent haemodynamic characteristics and a very low thromboembolic rate, probably related to the convex self-washing hinge mechanism. Consequently, we have reduced anticoagulant levels to INR (international normalised ratio) 1.5 to 2.0 for aortic valve patients in sinus rhythm. Early experience suggests that the ATS valve functions well in the tricuspid position.

Glial heterotopias of the nose: a report of two cases

Two neonates are presented who had glial heterotopias of the nose, one with and the other without intracranial connections. It is important to distinguish these malformations from nasofrontal encephaloceles in order to avoid inadvertent exposure of the brain during surgical removal of the mass lesions. The distinction between them may not be clear clinically because of their similar pathogenesis.

Post-heatstroke parkinsonism and cerebellar dysfunction

A case is presented of a 45-year-old woman who developed parkinsonism, cerebellar dysfunction, aphasia and flaccid paralysis secondary to heat stroke. Magnetic resonance imaging revealed irregular patchy areas of increased signal intensity in the white matter of both cerebral hemispheres and the left striatum, remaining unchanged over a follow-up period of two years. Cerebellar atrophy, while not seen on initial examination, was present on the follow-up study done one year later and became more marked after two years.

Ameloblastoma with stromal multinucleated giant cells

We report a case of ameloblastoma which uniquely showed heavy osteoclast-like giant cell accumulation and woven bone formation in the surrounding fibrous stroma. Immunohistochemistry showed that the giant cells were non-epithelial in origin and suggested that stromal factors (i.e., the presence or absence of mineralized bone) determines whether these cells express an osteoclastic antigenic phenotype.

Posttraumatic paroxysmal nocturnal hemidystonia

The term "nocturnal paroxysmal dystonia" has been used to describe patients who display paroxysmal episodes of dystonic-dyskinetic movements arising during nonrapid eye movement sleep, in particular stages 2-3 (Lugaresi E, Cirignotta F. Hypnogenic paroxysmal dystonia: epileptic seizure or a new syndrome. Sleep 1981;4: 129-138). The pathogenesis of these attacks has remained controversial. We describe a patient with posttraumatic paroxysmal nocturnal hemidystonia. Acetazolamide led to improvement.

Choroido-cerebral calcification syndrome with retardation

We present a sibship with a rare syndrome characterized by mental retardation, dense calcification of the lateral ventricular choroid plexus, and increased CSF protein. Neurophysiologic studies yielded nonspecific results, and endocrine studies, including parathormone levels, were normal. Simultaneous measurements of CSF and serum calcium, magnesium, and other electrolytes were normal, but the CSF/serum ratio of phosphate was low, suggesting a possible role in the pathogenesis of this syndrome.

Isolation and characterization of AMP deaminase from mammalian (rabbit) myocardium

AMP deaminase (AMP aminohydrolase, EC 3.5.4.6) is a ubiquitous enzyme in eukaryotes, which may play a role in ATP catabolism during myocardial ischaemia. We report isolation of AMP deaminase from rabbit myocardium with a 19% recovery and a 650-fold enrichment, using a newly devised protocol involving sequential cation-exchange, gel-permeation and affinity chromatographies. The cardiac AMP deaminase preparation described was electrophoretically and chromatographically homogeneous and contained one unique N-terminal residue (leucine). The isolated enzyme was sensitive to various cations (K+, Mg2+, Ca2+). The pH optimum of purified cardiac AMP deaminase was 6.8, its pI was 6.5, and it displayed substrate-specificity toward 5'-AMP. The subunit molecular mass of rabbit heart AMP deaminase on SDS/PAGE (81 kDa) and the holoenzyme molecular mass as estimated by non-denaturing size-exclusion h.p.l.c. (330 kDa) indicated that the native enzyme was a tetramer. Cardiac AMP deaminase displayed a sigmoidal substrate-saturation curve in the presence of 100 mM KCl. Apparent Michaelis constants were a Km of 5.8 mM AMP and a Vmax. of 11.1 mumol/min per mg of protein. ATP and ADP were positive allosteric effectors of cardiac AMP deaminase: the apparent Km was decreased to 1.7 mM by 1.0 mM ATP. The enzyme was inhibited by GTP, coformycin, coformycin 5'-phosphate, palmitoyl-CoA, inorganic phosphate compounds, and the metal chelator o-phenanthroline. No inhibition either by product nucleotide (IMP) or by nicotinamide nucleotides was detected when these agents were examined at concentrations up to 2.5 mM. We conclude that this enzyme preparation offers a means by which the kinetic mechanism and regulation of mammalian cardiac AMP deaminase may be directly investigated.

Mobius syndrome with basal ganglia calcification

Basal ganglia calcification has not been described in Mobius syndrome. A family with two children with Mobius syndrome are reported. Bilateral basal ganglia calcification was seen on computed tomography in both. This is the first family where cerebral involvement has been clearly documented in this syndrome.

Mucosal cell-mediated immunity to mycobacterial, enterobacterial and other microbial antigens in inflammatory bowel disease

Culture studies have suggested that Mycobacterium paratuberculosis may play a role in the aetiology of Crohn's disease. However, evidence of sensitization to mycobacterial antigens amongst patients with Crohn's disease has not yet been adequately demonstrated. Previous studies of cell-mediated immunity (CMI) in Crohn's disease were restricted to responses of peripheral blood mononuclear cells (PBMC) to mycobacterial antigens. In this study we have investigated the proliferative responses of both PBMC and mesenteric lymph node mononuclear cells (MLNMC) to a range of mycobacterial and non-mycobacterial antigens. There was no evidence of specific sensitization in the responses of MLNMC and PBMC from patients with inflammatory bowel disease (IBD) to the mycobacterial antigens. However, anergy to M. paratuberculosis could not be excluded. IBD MLNMC responses to most antigens were generally greater than those of PBMC, which were often undetectable. When compared with controls, there was evidence of increased CMI to a range of non-mycobacterial antigens, especially Yersinia enterocolitica, amongst both MLNMC and PBMC from patients with Crohn's disease and ulcerative colitis (UC). These results do not provide support to the proposed role of mycobacteria in the pathogenesis of Crohn's disease, but indicate that further investigation may determine a role for bacterial-specific T cell-mediated responses in the pathogenesis of IBD.

Multicentric glioma of the spinal cord

A 24-year-old woman with neurofibromatosis presented with a 1.5-year history of pain in the neck, both shoulders and back, and a 4-month history of progressively increasing weakness of all the limbs and inability to walk. The limb weakness fluctuated and, at the height of the weakness, it was associated with hesitancy and retention of urine. Magnetic resonance imaging (MRI) showed a fusiform enlargement of the upper cervical cord with obliteration of the subarachnoid space. Imaging after gadolinium-DTPA injection revealed inhomogeneous enhancement extending from the lower medulla down to the C4 cord level, and homogeneous enhancement at D3 to D4 and D6 to D8 cord levels. The spinal cord at the lower two levels appeared morphologically normal. At operation the fusiform enlargement of the cervical cord was confirmed. The tumour was partially removed. Histology revealed it to be a fibrillary astrocytoma.

The role of strictureplasty in Crohn's disease

Crohn's disease is a panintestinal disease of unknown aetiology and a tendency to recrudescence throughout the patient's life. It is therefore impossible to cure Crohn's disease by medical therapy or surgical excision. In spite of this, the majority of patients can be managed through their disease and maintained in a good state of health by a combination of medical and surgical treatment. Early attempts at surgical management of Crohn's disease in the 1930's and 1940's involved bypass procedures which were marred with serious complications of sepsis, development of cancer and increased rate of recurrence. By the 1950's resection became the preferred operation but there soon arose a controversy about the amount of bowel that should be removed. There were some who advocated radical excision; removing all diseased bowel with a large margin of apparently normal tissue on each side of the resection. Others found less radical resection safer as it preserved gut and also had no apparent effect on the rate of recurrence of the disease. Although this argument continued, the balance gradually shifted towards less radical surgery. Furthermore, the wave of conservatism led to the evolution of the concept of minimal surgery.

Strictureplasty for ileo-colic anastomotic strictures in Crohn's disease

We report an audit of outcome on 24 patients (16 females) who had a strictureplasty to treat ileo-colic anastomotic strictures. All except one patient had their original resection for Crohn's disease, and required reoperation because of symptoms of recurrent intestinal obstruction for a mean 9.3 months (range 1-36); the remaining patient was discovered to have ileo-colic anastomotic stricture before he underwent laparotomy for closure of loop ileostomy. At operation, four patients needed additional small bowel strictureplasties, two of whom also underwent small bowel resection for separate areas of phlegmonous disease. There was no post-operative mortality, three patients developed wound infection and one had a pelvic abscess, which settled on antibiotic therapy. Two patients have since died of unrelated disease. Five patients have since needed reoperation for recurrence; only one had a stricture at the site of previous strictureplasty. Over a mean follow-up of 70.8 months (range 18-393) all 22 living patients now have complete relief of symptoms.

MR imaging in hydatid disease

Hydatid cysts may develop anywhere in the body as a result of the presence of a viable parasite (Echinococcus granulosus). Depending on the condition of the parasite, the host reaction, and therapy, the hydatid cyst will degenerate and may eventually collapse, leaving an area of calcification in the host tissue. The purpose of this pictorial essay is to demonstrate the use of MR imaging in the diagnosis of the various stages of hydatid disease and in monitoring response to therapy.

Intractable hiccup induced by brainstem lesion

Four patients with brainstem lesions presented with intractable hiccup and mild to moderate neurological signs. Two of the patients had been initially diagnosed as having a psychogenic cause for their hiccup. Magnetic resonance imaging (MRI) demonstrated brainstem infarction in one case, tuberculoma at the junction of the medulla oblongata and the cervical spinal cord in two, and a vermian tuberculoma compressing the brainstem in one. The brainstem infarct and one of the medullary tuberculoma were not detected on high resolution enhanced computed tomography. The 3 patients with CNS tuberculoma were free of hiccup 1-5 months after antituberculous chemotherapy. It is proposed that hiccup is not an abnormal reflex, but a myoclonus generated by repetitive activity of the "inspiratory solitary nucleus" due to release of higher nervous system inhibitory/-regulatory control. The neuroanatomical network and the mechanisms underlying the formation of intractable hiccup are outlined. The value of MRI in the initial diagnosis and follow-up of patients with intractable hiccup due to brainstem lesions is emphasised.

MR imaging of intradural inflammatory diseases of the spine

Twenty-eight patients with intradural inflammatory disease of the spine were studied in order to characterize the MR imaging findings of infectious and inflammatory conditions. Patients were categorized according to the spinal compartment involved. Among the 12 patients in the intradural extramedullary group, unenhanced scans were either normal or nonspecific while contrast-enhanced scans were helpful in visualizing and localizing the lesion. Nevertheless, contrast-enhanced MR studies were unable to differentiate infection and inflammation from tumor in this compartment. Among 16 patients with intramedullary lesions, four had granulomatous disease and 12 had nongranulomatous disease. The granulomatous lesions resembled tumors and displayed MR characteristics of a focal lesion with large nodular enhancement. The patients with nongranulomatous intramedullary lesions exhibited two subsets of MR findings. In the first subset of nine patients, diffuse cord swelling and high signal were seen on long TR images, combined with either no enhancement or peripheral, diffuse, or speckled enhancement of the spinal cord on contrast-enhanced short TR images. In the second subset of three patients, minimal or no spinal cord swelling was displayed despite the visualization of high signal on long TR scans and nodular enhancement with contrast administration on short TR scans. Both subsets were sufficiently unique that nongranulomatous myelitis could usually be differentiated from spinal cord tumors.

Skeletal muscle metabolism in heart failure: a 31P nuclear magnetic resonance spectroscopy study of leg muscle

1. The gastrocnemius muscle of seven patients with mild to moderate chronic heart failure and of five healthy control subjects was studied using 31P nuclear magnetic resonance spectroscopy. Spectra were collected at rest and during an incremental, symptom-limited, exercise protocol. Blood flow was measured in the same study during brief interruptions to exercise. 2. The phosphocreatine/(phosphocreatine plus inorganic phosphate) ratio was lower in patients with heart failure than in control subjects at an exercise rate of 1.5 W, although intracellular pH and blood flow were similar. 3. The cytosolic free adenosine 5'-diphosphate concentration was markedly increased in patients with heart failure exercising at 1.5 W compared with control subjects exercising at the same workload. 4. Although the maximum workload achieved by patients with heart failure was less than half of that reached by control subjects, the pH and the phosphocreatine/(phosphocreatine plus inorganic phosphate) ratio were lower in patients with heart failure at maximal load. Blood flow was less at maximal exercise in patients with heart failure than in control subjects in keeping with the reduced work load. 5. The phosphocreatine depletion induced in the gastrocnemius muscle by exercise was more severe than previously described in the forearm of patients with heart failure. 6. Metabolic abnormalities in skeletal muscle may contribute to exercise intolerance in heart failure, particularly during submaximal exercise.

Value of AgNOR method in predicting recurrence of meningioma

Images

Results of combined valve replacement and myocardial revascularization. Relation to method of myocardial protection

One hundred and twenty-three patients underwent combined valve and coronary artery bypass surgery, between 1974 and 1985. Seventy patients had aortic valve replacement, 53 had mitral valve replacement; 63.4% were male and 45% were over 60 years (mean 59 +/- 2 years). Ischaemic cardiac arrest was used in 21 patients (Group I), cold crystalloid cardioplegia in 51 (Group II), and cold blood cardioplegia in 51 (Group III). Group III had a greater number of patients with poor preoperative functional status and left ventricular function. Early mortality was 19%, 17.6% and 11.7% in Groups I, II and III respectively (NS), and was not influenced by patients age, number of vessels with critical coronary artery disease and the type of the valve procedure. There was a significant decrease in the release of LDH and AST in Group III when compared with Group II (p less than 0.02 and p less than 0.01) respectively. The linearized rate of recurrence of angina (% per patient year) was 0.4, 0.95 and 0.07; and late mortality (% per 100 years) was 5.8, 3.2 and 2.6 in Groups I, II and III respectively. Patient survival and the quality of life has been improved since the introduction of cold blood cardioplegic protection.

The use of antipyrine clearance to measure liver damage in psoriatic patients receiving methotrexate

Salivary antipyrine clearance was measured in 15 patients with psoriasis receiving methotrexate and related to liver biopsy changes and routine liver function tests, to determine whether antipyrine clearance could be used as a non-invasive method for monitoring liver function. Comparison of the salivary antipyrine clearance in the methotrexate group (mean 0.51 ml/min/kg, range 0.26-0.81) with 15 matched psoriatic controls (mean 0.54 ml/min/kg, range 0.34-0.99) showed no significant difference. Liver biopsy changes were scored for fatty change, fibrosis, liver cell necrosis and portal tract infiltrate. Total liver biopsy scores correlated significantly with antipyrine clearance/kg body weight (r = -0.72, P less than 0.05). There was no significant correlation of total liver biopsy scores with the other liver function tests. Correlation of the individual liver biopsy changes and antipyrine clearance showed a significant correlation with fatty change (r = -0.75, P less than 0.01), but not with fibrosis (r = -0.53), liver cell necrosis (r = -0.54) or infiltrate (r = -0.41).