Purification of antigenically intact Ro ribonucleoproteins; biochemical and immunological evidence that the 52-kD protein is not a Ro protein.

Anti-Ro sera immunoprecipitate Ro ribonucleoproteins (RNPs) from human cell extracts. Ro RNPs are biochemically heterogeneous particles whose functions are unknown and whose exact composition remains controversial. In addition to 60-kD Ro and to La proteins, a 52-kD polypeptide (p52) has been proposed to be a stable component of the Ro RNPs. To confirm the immunological studies supporting this hypothesis, we have biochemically purified Ro RNPs from HeLa cells using non-denaturing conditions. Ro RNPs segregated into three distinct populations, one of which only contained hY5 RNA (RohY5 RNPs). No p52 co-purified with Ro RNPs. Despite the absence of p52, purified Ro RNPs had biochemical and immunological properties identical to those of unfractionated Ro RNPs. Many anti-Ro sera only recognize p52 in immunoblots, and are said to be monospecific anti-p52. Preincubation with purified RohY5 RNPs (free of p52) of all human anti-Ro (including so-called monospecific anti-p52) sera abolished their capacity to immunoprecipitate Ro RNPs from unfractionated HeLa cell extracts. Conversely, preincubation of anti-Ro sera with purified p52 protein specifically inhibited recognition of p52 in immunoblots, but did not interfere with immunoprecipitation of Ro RNPs. Our data demonstrate that anti-p52 antibodies do not target intact Ro RNPs, nor do they target the native 60-kD Ro protein. Contrary to previous reports, p52 protein is not a stable component of antigenically intact Ro RNPs.     

Prospective study of antigenemia,plasma viremia and lymphocytic viremia in HIV-infected hemophiliacs

A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p<0.05). Plasma viremia was closely associated (p<0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of >500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p<0.05).     

The Prospective Assessment of Autonomic Nerve Function by Pupillometry in Adolescents with Type 1 Diabetes Mellitus

The study aimed to compare the longitudinal assessment of autonomic nerve function by computerized infrared pupillometry and standard cardiovascular tests in adolescents with diabetes. Adolescents (n = 150) were assessed at two time points (T1 and T2). The median time interval between assessments was 1.5 (range 0.9–3) years. At T1 the median age was 14.5 (range 8.3–19.5) years and the median duration was 6.5 (range 1.1–16) years. The pupillary variables assessed included the resting pupil diameter, the maximum constriction velocity, and the reflex amplitude of constriction. Heart rate reflexes were assessed in response to deep breathing, the Valsalva manoeuvre, and on standing from a lying position (30/15 ratio). Between visits there was a significant decrease in maximum constriction velocity (6.0 mm s^?1 vs 6.3 mm s^?1, p = 0.0001) and resting pupil diameter (6.2 mm vs 6.3 mm, p = 0.001). At reassessment pupillary abnormalities increased from 32 (21 %) to 45 (30%), with 17 (54 %) of the initial abnormalities persisting. Adolescents with abnormally slow maximum constriction velocity compared to those with normal maximum constriction velocity had a higher glycated haemoglobin (HbA_1c%) at T2 (p = 0.02) and between assessments (p = 0.01). Cardiovascular test abnormalities did not increase between visits and the persistence of initial abnormalities was low (21 %). In summary, pupillometry appears a more sensitive test of autonomic nerve dysfunction in adolescents with diabetes than assessment of cardiovascular reflexes.     

Chronic vitamin E treatment prevents defective endothelium-dependent relaxation in diabetic rat aorta

Summary We examined the effect in rats of 2 months of streptozotocin-induced diabetes mellitus on relaxation and contraction of aortas in vitro. A further diabetic group was treated from time of diabetes induction with a 1% dietary supplement of vitamin E. Diabetes caused a 26.5% deficit (p<0.001) in maximum endothelium-dependent relaxation to acetylcholine in phenylephrine-precontracted aortas. This was 64.3% attenuated (p<0.01) by vitamin E treatment; maximum relaxation was not significantly altered compared to non-diabetic rats. Vitamin E treatment of non-diabetic rats did not significantly affect acetylcholine-induced relaxation. Diabetes or treatment did not significantly alter acetylcholine sensitivity. Endothelium-independent relaxation response to glyceryl trinitrate was not affected by diabetes or vitamin E treatment, indicating that vascular smooth muscle responses to nitric oxide remained unaltered. There was a 35.4% reduction in the maximum contractile response to phenylephrine with diabetes (p<0.05) which was unaffected by vitamin E treatment. The data suggest that the chronic deficit in nitric oxide-mediated endothelium-dependent relaxation in diabetes depends largely upon excess activity of reactive oxygen species. Treatment with vitamin E to increase free radical scavenging specifically protected vascular endothelium although it had no effect on deficits in vascular smooth muscle contractile responses.Abbreviations NO Nitric oxide - ARI aldose reductase inhibitor - ACH acetylcholine - GTN glyceryl trinitrate - GSH reduced form of glutathione - EC₅₀ effective concentration for 50% of the maximal response     

Effectiveness of a long-acting injectable form of bromocriptine in patients with prolactin and growth hormone secreting macroadenomas

OBJECTIVE With the development of new long-acting depot preparations of bromocriptine (bromocriptine LAR), we investigated the effectiveness of intramuscular injections of long-acting bromocriptine in patients with prolactin and GH secreting macroadenomas. STUDY DESIGN AND PATIENTS Fourteen patients with PRL secreting (8 patients) and GH secreting (6 patients) macroadenomas were treated with monthly intramuscular Injections of a long-acting and repeatable form of bromocriptine for 3–6 months. A 50-mg monthly dose was administered In the majority of patients with PRL secreting macroadenomas. A 100-mg monthly dose was administered In all patients with GH secreting macroadenomas. MEASUREMENTS Plasma PRL and/or GH levels were measured 6 and 12 hours after the first injection and then on days 1, 2,14 and 28 after each Injection, up to a maximum period of 6 months. Patients were hospitalized for 48 hours after each Injection and were specifically questioned with respect to side-effects. Pituitary imaging with MRI or CT scans was performed In all patients before commencing treatment and was subsequently repeated In 5/8 patients with macroprolactinomas and 5/6 patients with GH secreting macroadenomas after the completion of a 6-month course of treatment. RESULTS In ail patients with macroprolactinomas, serum PRL levels decreased significantly after their first 50-mg injection with nadir levels obtained by 24–48-hours post Injection (12815 ± 8704 vs 1480 ± 1859 mU/l; mean ± SD, P<0.01). At their latest follow-up, on a 50-mg monthly dose, 4 patients developed normoprolactinaemia (PRL levels <360mU/l) while two patients demonstrated a significant reduction In serum PRL levels (70 and 87% of pretreatment values). In two patients, although a substantial decrement of serum PRL levels was achieved 12-24 hours post injection, serum PRL levels Increased to pretreatment values by day 14 post injection. Both patients received a higher (100mg) monthly dose which was partially effective In one patient. In two patients with GH secreting macroadenomas, a sustained decrease of elevated GH levels was observed; in two patients, while a substantial reduction of the elevated serum GH levels was achieved 12–24 hours after the first and subsequent injections, serum GH levels increased to pretreatment values by day 14 post injection; in two patients there was no effect on the elevated serum GH levels. Significant tumour shrinkage (24–50%) was observed In 5/5 patients with PRL secreting macroadenomas assessed at completion of a 6-month course of treatment. Significant tumour shrinkage was also documented In 2/5 acromegalics tested (29 and 46% respectively). CONCLUSION It is concluded that bromocriptine LAR Is an effective treatment in the majority of patients with macroprolactinomas; it is also partially effective in some patients with GH secreting macroadenomas.     

Effect of ICV infusion of CRF on blood pressure and adrenal steroids in rabbits

The effect of prolonged, 22 h long, intracerebroventricular (i.c.v.) infusion of corticotropin-releasing hormone (CRF) on plasma cortisol, corticosterone and electrolyte concentrations, mean arterial blood pressure (MAP) and heart rate (HR) were investigated in conscious rabbits. During i.c.v. infusion of CRF, 1 and 3 μ/h, at a rate of 17 μl/h, plasma cortisol and corticosterone concentrations rose to the level noted after ACTH stimulation in rabbits. Plasma [Na] did not change, but plasma [K] was reduced and plasma osmolality increased during the infusion of CRF, 3 μ/h. MAP and HR, recorded continuously during i.c.v. infusion of CRF, changed only with the higher dose of CRF: MAP was elevated during the first 5 h of infusion, and then returned to the control level. HR was lower than control at the end of the first hour of infusion and again between 9 and 15 h of infusion. The prolonged rise of CRF concentration in the brain induced a sustained rise in circulating adrenal steroid hormones. MAP did not increase to the level noted after bolus i.c.v. injection of CRF and the rise in MAP was not sustained.     

Rare diseases mimicking acute vertebrobasilar artery thrombosis

Acute ischaemia of the vertebrobasilar circulation leads to a variety of clinical manifestation and is mostly due to cardiogenic or artery-to-artery embolism. We describe four neurological emergency situations involving vertebrobasilar artery aclusion of other origins: basilar migraine, extrinsic compression by rheumatoid inflammatory tissue, generalized vasculitis in subacute rheumatic fever and basilar artery dissection. The differential diagnosis of acute vertebrobasilar artery occlusion may have an important impact on patient management.     

Self-expanding nitinol stents in canine vertebral arteries: hemodynamics and tissue response.

PURPOSETo evaluate the hemodynamics and tissue response associated with stent placement in low-flow-velocity arteries.METHODSSix self-expanding nitinol stents (5.5 mm caliber) were implanted transfemorally within the proximal segments of vertebral arteries (2.5 mm diameter) in six adult dogs during anticoagulative protection.RESULTSControl angiograms demonstrated patency and 20% dilatation of all stented arteries. One artery was partially thrombosed 1 week later and subsequently showed a 50% stenosis. Throughout the observation period (4 to 9 months after stenting), the other five arteries remained patent without significant narrowing (< or = 15%). Small cervical muscle branches originating from the vertebral arteries within the stented segments remained patent. No major branch occlusions of the vertebrobasilar system were detected. Stent migration or kinking did not occur. MR studies of the brain 4 months after implantation revealed no infarcted areas. These findings were confirmed with brain sections. Stented artery specimens showed delayed stent dilatation. A comparison of the total mean thickness of intima covering the five 30- to 40-mm stents removed at 4, 6, and 9 months showed no significant difference (338, 332, and 389 microns, respectively). Histologic findings verified the macroscopic impression of a thicker intima at the inner curve of the stented artery segments and at the junctions of the stent filaments. The shortest (10 mm) stent had the thinnest neointimal growth (155 microns). Stented vessels showed compression of the media with atrophy, but without necrosis or perforation. Scanning electron photomicrographs revealed intact endothelial cell linings with typical elongated cells.CONCLUSIONSNo significant risk of thromboembolic events exists after implanting these nitinol stents in nonatherosclerotic vertebral arteries in dogs. Thicker neointimal growth after stenting may result from either low wall shear stress with possible flow separation or from changes in the shape and size of the stent, or both.     

Antiulcer activity of Tinospora cordifolia Miers and Centella asiatica linn extracts

The ethanol extracts of the roots of T. cordifolia Miers and C. asiatica Linn were observed to induce a marked protective action against an 8 h restraint stress induced ulcerization, the activity being comparable to that of diazepam.