Indirect bright light improves circadian rest-activity rhythm disturbances in demented patients

Light is known to be an important modulator of circadian rhythms. We tested the hypothesis than an enduring increase in the daytime environmental illumination level improves rest-activity rhythm disturbances in demented patients. Actigraphy was performed before, during, and after 4 weeks of increased illumination in the living rooms of 22 patients with dementia clinically diagnosed as probable Alzheimer's disease, multi-infarct dementia, dementia associated with alcoholism, or normal pressure hydrocephalus. The results indicated that during increased illumination, the stability of the rest-activity rhythm increased in patients with intact vision, but not in visually impaired patients.     

Pathologic staging of papillary carcinoma of the thyroid with airway invasion based on the anatomic manner of extension to the trachea: a clinicopathologic study based on 22 patients who underwent thyroidectomy and airway resection

We received the clinical and pathologic features of 22 cases of papillary carcinoma of the thyroid that invaded the trachea and were treated by thyroidectomy and airway resection with or without reconstructive surgery over an interval of 16 years. We studied the fine relationships between lamina propria and lymphatics in the region between the isthmus of the thyroid and the trachea. The manner of invasion of papillary carcinoma of the thyroid was by blunt dissection along blood vessels and collagen fibers oriented perpendicularly to the tracheal lumen between cartilaginous rings. Although lymph node metastases were found in 14 patients (64%), we observed lymphangitic tumor in the tracheal mucosa in only three patients (14%). We devised a staging system for papillary carcinoma of the thyroid based on the extent of invasion of the trachea. Of the 11 patients with stage I, II, or III disease, none of six (0%) followed for 5 years died of thyroid cancer in the 5-year observation period; one patient in this group died later of thyroid cancer. Of the 11 patients with stage IV disease, five of seven (71%) followed for 5 years died of thyroid cancer in the 5-year observation period; one additional patient in this group died later of thyroid cancer.     

Anticoagulation with low molecular weight heparin (Fragmin) during continuous hemodialysis in the intensive care unit

A preparation of low molecular weight heparin (Fragmin) was administered to patients with multiorgan failure receiving continuous venovenous hemodialysis. Three patients received a high-dose regimen (35 IU/kg bolus followed by 13 IU/kg infusion), and 7 received a low-dose regimen (8 and 5 IU/kg, respectively) for 36 h. High-dose Fragmin was associated with minimal clotting in the extracorporeal circuit. Plasma fibrinopeptide A levels declined, and mean anti-Xa activity was in the range 0.47-0.79 IU/ml. The urea equilibration coefficient (UEC) (100% at initiation) remained above 90% throughout. All 3 patients had mild bleeding episodes, which led to discontinuation of Fragmin in 1. During all low-dose treatments, marked thrombus formation occurred in the extracorporeal circuit, and in 2, the circuit clotted within the study period. Fibrinopeptide A levels further increased in 4 patients, and mean anti-Xa activity was in the range 0.27-0.53 IU/ml. UEC declined appreciably in 3 treatments (including the 2 in which early circuit clotting occurred). One patient experienced a mild bleeding episode. The low-dose Fragmin regimen produced safer anticoagulation in patients at risk from bleeding and is suitable for prolonged renal support although the tendency to thrombosis may necessitate more frequent circuit changes.     

RanBP1 stabilizes the interaction of Ran with p97 nuclear protein import

Three factors have been identified that reconstitute nuclear protein import in a permeabilized cell assay: the NLS receptor, p97, and Ran/TC4. Ran/TC4, in turn, interacts with a number of proteins that are involved in the regulation of GTP hydrolysis or are components of the nuclear pore. Two Ran-binding proteins, RanBP1 and RanBP2, form discrete complexes with p97 as demonstrated by immunoadsorption from HeLa cell extracts fractionated by gel filtration chromatography. A > 400-kD complex contains p97, Ran, and RanBP2. Another complex of 150-300 kD was comprised of p97, Ran, and RanBP1. This second trimeric complex could be reconstituted from recombinant proteins. In solution binding assays, Ran-GTP bound p97 with high affinity, but the binding of Ran-GDP to p97 was undetectable. The addition of RanBP1 with Ran-GDP or Ran-GTP increased the affinity of both forms of Ran for p97 to the same level. Binding of Ran-GTP to p97 dissociated p97 from immobilized NLS receptor while the Ran-GDP/RanBP1/p97 complex did not dissociate from the receptor. In a digitonin-permeabilized cell docking assay, RanBP1 stabilizes the receptor complex against temperature-dependent release from the pore. When added to an import assay with recombinant NLS receptor, p97 and Ran-GDP, RanBP1 significantly stimulates transport. These results suggest that RanBP1 promotes both the docking and translocation steps in nuclear protein import by stabilizing the interaction of Ran-GDP with p97.     

The major histocompatibility complex region marked by HSP70-1 and HSP70-2 variants is associated with clozapine-induced agranulocytosis in two different ethnic groups

Genes of the major histocompatibility complex (MHC) have been associated with susceptibility to drug-induced adverse reactions. We previously found that clozapine-induced agranulocytosis (CA) is associated with the HLA-DRB1*0402, DRB4*0101, DQB1*0302, DQA1*0301 haplotype in Ashkenazi Jewish patients and with the HLA-DRB1*1601, DRB5*02, DQB1*0502, DQA1*0102 haplotype in non-Jewish patients. In the present study, we tested the hypothesis that the variants of the heat-shock protein 70 (HSP-70) encoded by the HSP-70 loci located within the MHC region and known to be involved in apoptosis and regulation of cell proliferation could play an important role in molecular mechanisms of CA. First, we analyzed HSP70-2 polymorphism in risk-associated haplotypes from HLA homozygous cells and normal individuals and confirmed that the HSP70-2 9-kb variant was associated invariably with DR4 (HLA-DRB1*0402, DQB1*0302) and DR2 (HLA-DRB1*01601, DQB1*0502, DQA1*0102 and HLA-DRB1*1501, DQB1*0602) haplotypes, which were the haplotypes found increased in Jewish and non-Jewish patients with CA, respectively. The 9.0-kb variant was also found to be associated with HLA-B44, DRB1*0401 and HLA-B44, DRB1*07 haplotypes. Second, in patients with CA (12 Ashkenazi Jewish and 20 non-Jewish patients), HSP70-1 A and HSP70-2 9.0-kb variants were associated with the MHC haplotypes found by us to be markers of susceptibility to CA. The clozapine-treated control group had an excess number of HSP70-1 C and HSP70-2 8.5-kb variants, consistent with genetic resistance to CA associated with those variants. This finding supports our hypothesis that a dominant gene within the MHC region (marked by HSP70-1 and HSP70-2), but not necessarily HLA, is associated with CA in two different ethnic groups.     

Color duplex ultrasonography in the diagnosis of temporal arteritis

BACKGROUND: The diagnosis of temporal arteritis usually requires a biopsy of the temporal artery. We examined the usefulness of color duplex ultrasonography in patients suspected of having temporal arteritis. METHODS: In this prospective study, all patients seen in the departments of rheumatology and ophthalmology from January 1994 to October 1996 who had clinically suspected active temporal arteritis or polymyalgia rheumatica were examined by duplex ultrasonography. The final diagnoses, made according to standard criteria, were temporal arteritis in 30 patients, 21 with biopsy-confirmed disease; polymyalgia rheumatica in 37; and negative histologic findings and a diagnosis other than temporal arteritis or polymyalgia rheumatica in 15. We also studied 30 control patients matched for age and sex to the patients with arteritis. Two ultrasound studies were performed and read before the biopsies; one ultrasonographer was unaware of the clinical information. RESULTS: In 22 (73 percent) of the 30 patients with temporal arteritis, ultrasonography showed a dark halo around the lumen of the temporal arteries. The halos disappeared after a mean of 16 days (range, 7 to 56) of treatment with corticosteroids. Twenty-four patients (80 percent) had stenoses or occlusions of temporal-artery segments, and 28 patients (93 percent) had stenoses, occlusions, or a halo. No halos were identified in the 82 patients without temporal arteritis; 6 (7 percent) had stenoses or occlusions. For each of the three types of abnormalities identified by ultrasonography, the interrater agreement was > or =95 percent. CONCLUSIONS: There are characteristic signs of temporal arteritis that can be visualized by color duplex ultrasonography. The most specific sign is a dark halo, which may be due to edema of the artery wall. In patients with typical clinical signs and a halo on ultrasonography, it may be possible to make a diagnosis of temporal arteritis and begin treatment without performing a temporal-artery biopsy.     

Selective inhibition of factor Xa is more efficient than factor VIIa-tissue factor complex blockade at facilitating coronary thrombolysis in the canine model

OBJECTIVES: We determined the effect of adjunctive inhibition of the extrinsic coagulation pathway by factor VIIa-tissue factor complex inhibitors, DEGR VIIa and tissue factor pathway inhibitor (TFPI), and the selective factor Xa inhibitor, tick anticoagulant peptide (TAP), after thrombolytic therapy with tissue-type plasminogen activator (t-PA) in a canine model of electrically induced coronary thrombosis. BACKGROUND: Ongoing thrombin generation is considered an important component of the heightened thrombin activity associated with thrombolytic therapy and may be responsible for reperfusion failure and reocclusion. METHODS: Forty-two dogs with electrically induced coronary thrombus undergoing thrombolysis with t-PA (1 mg/kg over 20 min) were randomly assigned to one of the following adjunctive regimens: TAP (30 micrograms/kg body weight per min for 90 min, n = 10); TFPI (100 to 150 micrograms/kg per min for 90 min, n = 10); DEGR VIIa (1- to 2-mg/kg bolus, n = 10) and saline control (n = 12). The dogs were observed for 120 min after thrombolysis for reocclusion. RESULTS: All three active study agents accelerated the time to reperfusion by an average of 12 min (all p < 0.05). Duration of reflow was greatest with TAP (117 +/- 8 min, p < 0.05 compared with saline control), whereas DEGR VIIa and TFPI did not prolong the duration of reflow. Reocclusion rates were similar among control, DEGR VIIa and TFPI groups (70%, 78% and 67%, respectively). Tick anticoagulant peptide reduced the occurrence of reocclusion (0%, p < 0.05 compared with saline control). CONCLUSIONS: In this experimental model, during systematic blockade of various extrinsic coagulation pathway proteins, we demonstrated that whereas acceleration of thrombolysis occurs with factor VIIa-tissue factor complex inhibition, optimal enhancement of thrombolysis was achieved through specific factor Xa blockade.