(1)H MR Spectroscopy in Gliomatosis: Is there a Sensitivity Issue?

Objective. (1)H MR spectroscopy (MRS) is widely performed for assessment of brain tumours and is considered a highly sensitive technique capable of differentiating benign from malignant conditions and tumour grading. Method. We present a case of a 69 year old woman who was suspected to have gliomatosis on MRI. Results. MRS performed using single voxel and chemical shift/multivoxel techniques was within normal limits. A repeat scan 6 months later showed progressive disease, and biopsy was performed that proved the diagnosis of glioblastoma. Conclusion. Normal MRS in a patient with suspicion of gliomatosis on MRI should not reassure clinicians into assuming a benign aetiology or a good prognosis in short term.

A case of raised intracranial pressure due to multiple lumbar nerve root melanotic schwannomas.

We report a patient with multiple cranial nerve and lumbar spine nerve root melanotic schwannomas, a rare variant of schwannoma, with raised intracranial pressure. Possible pathophysiology of the raised intracranial pressure by decreased CSF resorption due to blocked spinal lymphatics and other mechanisms is discussed.

An Algorithm for Optimizing Rotational Control of Globodera rostochiensis on Potato Crops in Bolivia.

The outline area of new cysts of Globodera rostochiensis was measured by image analysis. A linear regression of this value against egg content provided a basis for adjusting the egg number for cyst size. This adjusted egg content provides an estimate of the relative fullness of a cyst with eggs. This value showed an exponential decline in eggs over 3.5 years since the last potato crop. It corresponds to an average loss in the dormant egg population of 32.8 +/- 5.6%/year for 26 fields at Toralapa, Bolivia. This value compared well with a mean decline of 40 +/- 4%/year for 42 fields after measuring viable eggs/100 g soil on two occasions one year apart. The new approach allows declines to be estimated at one time point. The decline in lipid content of the dormant, unhatched second-stage juveniles (J2) was 17 +/- 6% per annum as measured by image analysis after Oil red O staining. This may be sufficient to compromise infectivity after 3 to 4 years of dormancy. A standard model was modified to consider the effect of both lipid depletion during dormancy and choice of susceptible potato on the population dynamics of G. rostochiensis under rotational control. It is concluded that a few cultivars may impose lower populations on G. rostochiensis in 3 to 4-year rotations than the majority used in Bolivia.

Prediction of late cardiac events by dipyridamole thallium scintigraphy in patients with intermittent claudication and occult coronary artery disease.

Concomitant coronary artery disease often occurs in patients with peripheral vascular disease, but it may be asymptomatic. Despite being asymptomatic, cardiovascular events are the main source of morbidity and mortality in this group of patients. Dipyridamole thallium scintigraphy has been shown to be of prognostic value in patients with peripheral vascular disease and symptomatic coronary artery disease, but its effect on the long-term outcome in the asymptomatic group of patients is less defined. Eighty-four consecutive patients with peripheral vascular disease and no symptoms of coronary artery disease were therefore evaluated by clinical assessment, dipyridamole thallium imaging, radionuclide ventriculography, and cardiac catheterization and followed for a mean of 66 months. Abnormal perfusion patterns were found on thallium scintigraphy in 48 patients (57%); fixed, mixed, and reversible defects were present in 14 (17%), 11 (13%), and 23 (27%) patients, respectively. Significant coronary artery disease was present in 52 patients (69%) and mean left ventricular ejection fraction was 44%. During the follow-up period, 23 patients had a cardiac event (nonfatal myocardial infarction or cardiac death). Univariate analysis of 15 clinical, scintigraphic, radionuclide, and angiographic variables revealed that age, angiographic extent of coronary artery disease, and an abnormal thallium scan were significant predictors of subsequent cardiac events. Multivariate stepwise logistic regression analyses selected fixed and mixed thallium defects and diffuse coronary artery disease as the only significant independent predictors of outcome. Thus, the present study shows the value of dipyridamole thallium scintigraphy as a valuable prognostic indicator for long-term event-free survival in a cohort of patients with peripheral vascular disease and no history or symptoms of coronary artery disease.

Sensitivity and specificity of QTc dispersion for identification of risk of cardiac death in patients with peripheral vascular disease.

OBJECTIVE: To determine whether QTc dispersion, which is easily obtained from a standard electrocardiogram, can predict those patients with peripheral vascular disease who will subsequently suffer a cardiac death, despite having no cardiac symptoms or signs. DESIGN: Patients with peripheral vascular disease were followed up for five years after they had had coronary angiography, radionuclide ventriculography, and their QTc dispersion calculated from their 12 lead electrocardiogram. SUBJECTS: 49 such patients were then divided into three groups: survivors (34), cardiac death (12), and non-cardiac death (3). MAIN OUTCOME MEASURE: Survival. RESULTS: The mean (SD; range) ejection fractions were similar in all three groups: survivors 45.9 (11.0; 27.0-52.0), cardiac death 44.0 (7.90; 28.5-59.0), and non-cardiac death 45.3 (4.55; 39.0-50.0). QTc dispersion was significantly prolonged in the cardiac death group compared with in the survivors (86.3(23.9; 41.0-139) v 56.5 (25.4; 25.0-164); P = 0.002). A QTc dispersion > or = 60 ms had a 92% sensitivity and 81% specificity in predicting cardiac death, QTc dispersion in patients with diffuse coronary artery disease was significantly (P < 0.05) greater than in those with no disease or disease affecting one, two, or three vessels. CONCLUSIONS: There is a strong link between QTc dispersion and cardiac death in patients with peripheral vascular disease. QTc dispersion may therefore be a cheap and non-invasive way of assessing the risk of cardiac death in patients with peripheral vascular disease.

A comparison of maximal exercise and dipyridamole thallium-201 planar gated scintigraphy.

Both symptom-limited maximal exercise and intravenously given dipyridamole stress (0.56 mg/kg over 4 min with a 2 min walk) gated thallium scans were performed in 22 patients undergoing coronary arteriography for the assessment of chest pain. All scans were acquired gated to the electrocardiogram in 3 projections and were reported for the presence and extent of defects in 5 myocardial segments in each view. In addition, left and right ventricular myocardial uptake and estimates of right and left lung and liver to left ventricular uptake were assessed relative to the injected dose of thallium-201. Overall, 190/310 segments were abnormal with exercise compared with 169/310 with dipyridamole. Segments were scored greater in extent in 90/310 cases with exercise, compared with 46/310 in which the defect was more extensive with dipyridamole (P less than 0.0005). Non-attenuation corrected percentage myocardial thallium uptakes were similar for both stresses: anterior percentage uptakes, 0.785% +/- 0.230% with exercise versus 0.870% +/- 0.217% with dipyridamole (NSD). Left and right lung and liver to left ventricle ratios were all significantly higher with dipyridamole than with exercise (1.587 +/- 0.408 versus 1.446 +/- 0.518, P less than 0.02; 1.78 +/- 0.479 versus 1.46 +/- 0.502, P less than 0.002; 2.598 +/- 0.788 versus 1.265 +/- 0.386, P less than 0.001, respectively). High right and left lung uptakes with dipyridamole were strongly correlated with high exercise values (r = 0.756, P less than 0.001; r = 0.809, P less than 0.001). The liver uptake was weakly correlated between the 2 different stress tests (r = 0.483, P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Physiological roles of chicken LHRH-I and -II in the control of gonadotrophin release in the domestic chicken.

The physiological roles of chicken LHRH-I and -II (cLHRH-I and -II) in the regulation of gonadotrophin release were investigated in the domestic chicken. Measurements of the neuropeptides, using specific radioimmunoassays, in brain sections cut in three planes or in grossly dissected brain areas, showed that cLHRH-II occurs in low amounts throughout the brain whereas cLHRH-I is most abundant in the diencephalon. Within the diencephalon, the largest amount of cLHRH-I occurred in the median eminence of the hypothalamus. The amount of cLHRH-I in the median eminence was higher (P less than 0.05) in laying than in out-of-lay hens. No cLHRH-II was detected in the median eminence in either reproductive state. The amount of cLHRH-I in the hypothalamus was increased (P less than 0.05) in cockerels at the onset of puberty and in somatically immature birds after castration. There were no correlated changes in the amounts of hypothalamic cLHRH-II measured in the same experimental samples. Active immunization of laying hens against cLHRH-I but not against cLHRH-II resulted in the complete regression of the reproductive system and a depression in the concentration of plasma LH. These observations, taken together, suggest that gonadotrophin secretion in the hen is more likely to be directly regulated by cLHRH-I than by cLHRH-II.

Incidence of arrhythmias in dental anaesthesia: a cross-over comparison of halothane and isoflurane.

Fifty patients received halothane anaesthesia during the surgical removal of 3rd molars from one side of the mouth and isoflurane during extractions on the other. Degree of surgical difficulty was matched, and end-tidal PCO2 did not differ significantly between sides. A significantly higher incidence of arrhythmias occurred during halothane, compared with isoflurane, anaesthesia. This difference occurred primarily when halothane was given for the first operated side. A clinically important feature of the stability of cardiac rhythm during isoflurane anaesthesia was demonstrated--when frequent ectopic beats occur during halothane anaesthesia, a significant decrease in the rate of premature contractions occurs within 3 min of discontinuing halothane and introducing isoflurane.

Successful reversal of sleep apnoea syndrome following treatment for acromegaly, confirmed by polygraphic studies.

A patient with acromegaly was shown to have obstructive sleep apnoea by polygraphic recordings. Following successful hypophysectomy, further recordings demonstrated resolution of obstructive sleep apnoea.

A practical approach to pre-hospital coronary care.

Prehospital coronary care involving a doctor and nurse team transported from the hospital by taxi has operated in Dundee for 18 months. Comparison of this service with the previous service shows it to be as effective, safe and relatively inexpensive.

The influence of cardiac staffing resources on permanent cardiac pacemaker implantation rates.

In Tayside region, from 1976 to 1986, the number of permanent pacemakers implanted per year more than doubled, with the increase particularly marked over the latter five years. In order to determine the factor(s) which had caused this increase in implantation rates, a retrospective analysis of patients undergoing pacemaker implantation during the period 1981-1986 was undertaken. No change in the number of elderly in the population, age of patients, mode of referral, waiting time before insertion or clinical indications for pacing was observed to account for this change. The advent of ambulatory ECG monitoring may have contributed to this increase, but the appointment of an extra cardiologist in Tayside in 1982 was believed to have been more important. These results suggest that the number of pacemakers implanted in a region is highly dependent on the number of cardiological staff in that region available for their insertion.

Percutaneous biopsy following positive bone scans.

When a bone scan reveals an abnormal radionuclide accumulation and the cause is uncertain, bone biopsy is sometimes necessary. One hundred thirty biopsies have been performed in our institution with a percutaneous needle guided by fluoroscopy. This procedure is safe and effective.