Adenosine technetium-99m-methoxy isobutyl isonitrile myocardial tomography in patients with coronary artery disease: comparison with exercise

We compared the results of adenosine and bicycle exercise 99mTc-methoxy isobutyl isonitrile (MIBI) myocardial SPECT in 22 patients (18 males and 4 females, mean age 51 +/- 11 yr) with angiographically documented coronary artery disease (CAD).

METHODS

All patients were submitted on separate days to three intravenous injections of 99mTc-MIBI (20 mCi); one at rest, one during exercise and one during adenosine (140 micrograms/kg per min for 6 min with injection of 99mTc-MIBI at 4 min). A total of 484 myocardial segments were quantitatively analyzed.

RESULTS

Adenosine induced a significant increase of heart rate (94 +/- 16 bpm at peak versus 70 +/- 13 bpm at rest, p < 0.01). Systolic and diastolic blood pressure were not significantly different after adenosine infusion compared to rest. In all segments, a significant relationship between exercise and adenosine 99mTc-MIBI uptake was observed (r = 0.90, p < 0.0001). Concordance between the two studies for identification of perfusion status was observed in 438 (90%) of the 484 segments (kappa value of 0.81). Agreement on localization of the perfusion defect to a specific vascular territory was 92%.

CONCLUSION

Despite different hemodynamic effects, adenosine and exercise 99mTc-MIBI SPECT imaging provide similar information in the diagnosis and localization of CAD.

Relative protection from cerebral atherosclerosis of young patients with homozygous familial hypercholesterolemia

It is well known that hypercholesterolemia is correlated with coronary atherosclerosis, but no definite information is available on its association with cerebrovascular atherosclerosis. We studied 10 young patients (age 3-32 years) with homozygous familial hypercholesterolemia (FH), together with 3 normal relatives as healthy controls. Extra- and intracranial Doppler examination, MRI and cerebral blood flow by SPECT and 99mTc-HM-PAO were performed on all. Six out of 10 patients already had signs and symptoms of coronary heart disease, but all patients were free from ischemic brain lesions, as small as detectable at MRI, and had normal cerebral blood flow. Two patients presented significant stenosis of the carotid arteries at Doppler examination. Young patients with homozygous FH have early and clinically evident coronary atherosclerosis, while overt disease in the cerebral district is delayed despite the extremely elevated plasma cholesterol concentration. This was also confirmed by the autopsy of two patients, who died after the study and whose cerebral arteries were totally free from atherosclerotic lesions. The age, at which flow-reducing atherosclerotic lesions develop in hypercholesterolemic patients, differs with regard to the arterial district involved.

Effect of acute administration of L-acetyl carnitine on cerebral blood flow in patients with chronic cerebral infarct

The effect of L-acetyl carnitine (L-AC) on cerebral blood flow (CBF) was evaluated in 20 patients with chronic cerebrovascular disease, who suffered an ischaemic stroke at least 6 months before the study. All patients performed a CT scan and were investigated with xenon-133 by brain dedicated single photon emission computed tomography (SPECT, Tomomatic 32, Medimatic Inc., Copenhagen). A single high dose (1.5 g) of L-acetyl carnitine was intravenously administered to 10 patients, while sodium acetate as placebo was injected to 10 other subjects. Cerebral blood flow (ml/min x 100 g) was evaluated before and 45 min after the injection. No changes were observed after placebo injection (43 +/- 12 ml/min x 100 g versus 43 +/- 10 ml/min x 100 g). CBF increased (from 42 +/- 9 ml/min x 100 g to 46 +/- 9, P less than 0.05) in both ipsilateral and contralateral hemisphere, the ischaemic area, but not in the stroke corresponding zone. It was concluded that L-acetyl carnitine at the i.v. dosage of 1.5 g acutely enhanced CBF in patients with chronic cerebral infarct.

Mixed transcortical aphasia: clinical features and neuroanatomical correlates. A possible role of the right hemisphere

This paper reports the clinical features of 2 patients affected by mixed transcortical aphasia. Both of them had extensive damage of the left hemisphere. Cerebral blood flow measurement showed a marked decrease in left-hemisphere flow. In particular, speech areas were found to be morphologically and functionally damaged. The present findings, together with a critical review of the literature, served as a starting point for a discussion of linguistic features, diagnostic criteria and classical neuroanatomical interpretation of mixed transcortical aphasia. The possible contribution of the right hemisphere in determining this aphasic syndrome is suggested.

Cerebral blood flow in thalamic aphasia

A 59-year-old man is reported, who became aphasic after left thalamic infarction, shown by CT. His speech was fluent, with reduced voice volume, impaired auditory and reading comprehension, verbal paraphasias but intact repetition skills. A single photon emission computed tomography (SPECT) scan to measure regional cerebral flow (rCBF) showed a reduction of flow in the parietotemporal areas of the left hemisphere. It is suggested that thalamic aphasia could result from structural subcortical damage with a homolateral functional cortical deficit leading to the specific aphasic disturbance.

[Effects of pentobarbital on serum PRL and TSH in the basal condition and under TRH stimulation in man: preliminary note]

The Authors have tested serum levels of PRL and TSH in six healthy males, anaesthesized with 20 mg./Kg. body weight of pentobarbital with and without stimultion with TRH. PB has no effect on serum levels of TSH but there is an inhibition of PRL release 180', 240' and 360' after the administration of the drug. The AA. have found no effects of PB on the stimulation test with TRH. All the data obtained have been examined with Student's "T" test.

[Effect of atropine on hypophyseal gonadotropins in the basal condition and under GnRH stimulation]

The Authors have tested serum levels of LH and FSH in 10 healthy males after stimulation test with GnRH preceded by administration i.m. of 1 mg. of atropine 10' and 1 hour before the test, to examine some interferences of the drug on ipophisary gonadotropins. Atropine has no effect on LH and FSH release because there are no differences between mean values of the hormones during the test with and without atropine, at any time it is administered. All the data obtained have been controlled with Student's "t" test.

[Inhibitory effects of atropine on serum prolactin levels after TRH stimulation]

The authors have tested serum levels of PRL after administration of atropine 10' and 60' before stimulation test with TRH, in 12 male and 12 female. The administration of the drug 10' before TRH has inhibited the PRL release, in all the groups. No effect presented atropine if administered 60' before TRH test.

[Effects of pentobarbital on serum levels of LH and FSH, in normal conditions and after GnRH stimulation: preliminary report]

The authors have tested serum levels of LH and FSH in healthy males anaesthetized with 20 mg/Kg body weight of pentobarbital, and stimulation test with GnRH. LH has reached levels higher than the stimulation test has been practised in the anaesthetized volunteers than in subjects awakes. The AA. have also showed that there is no effect on psychic stress and of atropine, used as preanaesthetic drug, on serum levels of the pituitary hormones. At the end, PB has no effect on serum levels of FSH.

Correlation between unilateral exophthalmos and thyroid diseases

43 clinically euthyroid patients with unilateral exophthalmos were examined using clinical methods, echography, and computerized tomography. The functioning of the hypothalamic-hypophyseal-thyroid axis was investigated by measurements of TSH (before and after stimulation with TRH), thyroid hormones and antithyroglobulin antibodies. After a review of the literature, the results are discussed.

Comparison of a water-soluble and a water-insoluble podophyllotoxin derivative in murine neoplasms

Comparison of a water-soluble (27-487) with a water-insoluble (VP-16-213) podophyllotoxin derivative in seven murine neoplasms revealed slight therapeutic superiortiy of VP-16-213 but also slightly greater toxicity when compared with 27-487. A strikingly good response of the Taper liver tumor to both compounds was observed, providing further incentive to the use of podophyllotoxin derivatives in human hepatomas.

Cyclosporins: immunosuppressive agents with antitumor activity

Initial screening of the 2 recently developed immunosuppressive agents, cyclosporin A and cyclosporin C, in 11 murine transplantable neoplasms revealed significant increase of lifespan with long-term survivors after i.p. injection to the ascites tumors, Taper liver, Sarcoma 180J and Ehrlich.

Kinetics of erythroid and myeloid stem cells in post-hypoxia polycythaemia

The number of erythroid burst-(BFU-E) and colony-forming units (CFU-E), as well as of myeloid-macrophage colony-forming units (CFU-C), has been evaluated in tibial marrow and spleen of ex-hypoxic polycythaemic mice, at sequential time intervals after the end of hypoxia. In both marrow and spleen, the kinetics of the CFU-E pool is characterized by a sharp fall from above normal to lower than normal values. BFU-E and CFU-C however rise from below normal to higher than normal levels. These results have been correlated with both the erythropoietin (Ep) and the erythropoietic activity curves. It is apparent that Ep levels largely control both the differentiation and the amplification of the CFU-E pool and it is suggested that Ep may act as a 'survival factor' at the CFU-E level and/or increase the flow of cells from BFU-E to CFU-E. The difference in response between CFU-E and BFU-E favours a clearcut distinction between these populations, whereas the similarity between the BFU-E and CFU-C response suggest a close relationship between these two cell populations. It is also of interest that the murine spleen functions as a large reservoir of erythroid microenvironment for hypoxia-induced stress erythropoiesis.

Combinations of tetrahydrouridine and cytosine arabinoside in mouse tumors

Thirteen experimental mouse neoplasms were tested by cytidine (CR)-deaminase and deoxycytidine (dCR)-kinase levels. Four neoplasms, Sarcoma T241, Adenocarcinoma E0771, Lewis lung carcinoma (LL), and Sarcoma 180 Japan (S180J), considered to have high deaminase and sufficient dCR-kinase activities, were tested in vivo for combination chemotherapy with cytosine arabinoside (ara-C) and the CR-deaminase inhibitor, tetrahydrouridine (THU). THU did not significantly improve the growth inhibition of ara-C in a wide range of combinations in T241, E0771, LL, and the solid form of S180J, but more than doubled the survival time of the S180J ascites-bearing animals. Toxicity in the form of weight loss and toxic deaths was observed in some but not all groups, especially at high dosages of ara-C and THU. Tissue distribution of [3H]-ara-C and [14C]-THU in T241-bearing mice revealed an accelerated clearance of ara-C-derived radioactivity under the influence of THU in the tumor and five host tissues, but not in the small intestines. With the exception of the small intestines, clearance of THU-derived radioactivity was faster in all tissues studied compared to the clearance of [3H]-ara-C-derived radioactivity. Intracellular CR-deaminase levels were inhibited significantly, ie, dose dependent, in tumor and host kidney after a single ip injection of THU to E0771--bearing mice. In the solid S180J, with or without simultaneous ip administration of THU, [3H]-ara-C was not converted to 5'-di- and tri-phosphates at all. In mice bearing the ascites form of S180J, [3H]-ara-C was extensively converted to ara-C 5'-di- and tri-phosphates. THU increased both overall ara-C-derived radioactivity and the relative amounts of ara-C 5'-di- and tri-phosphates.