Intra-arterial infusion of [125I]A beta 1-40 labels amyloid deposits in the aged primate brain in vivo

Alzheimer's disease is characterized by extracellular amyloid deposits in the brain at both vascular sites (cerebrovascular amyloid, CVA) and within the neuropil (plaques). In the present study we demonstrated that brain amyloid of aged non-human primates is efficiently detected by [125I]A beta in vitro, and assessed the detection of that amyloid in vivo by intravascular infusion of [125I]A beta. Aged squirrel monkeys (Saimiri sciureus) were anesthetized and infused intra-arterially with [125I]A beta, and sacrificed 2 h later. Analysis of the anterior frontal and temporal cortices by autoradiography demonstrated that [125I]A beta was deposited on CVA and that essentially every amyloid deposit which could be detected with thioflavin S or anti-A beta antibodies was also labeled by [125I]A beta. These experiments suggest that intravascular infusion of radiolabeled A beta can be used to detect and image amyloid deposits in the human AD brain.

Negative intraoral air pressures of deaf children with cochlear implants: physiology, phonology, and treatment

The primary purpose of this investigation was to examine deaf children's use of negative intraoral air pressures (-Po's) from a physiological and a phonological perspective, with the hope of gathering insight into the strategies these children use to produce speech. A secondary purpose was to compare the effectiveness of two methods of treating these deviant productions. Subjects were four profoundly deaf children, age 6:6-9:2, who used cochlear implants and had demonstrated persistent use of -Po's. Po's were collected during production of CV syllables with initial [p] and [b] and a variety of vowel contexts. Two of the children used -PO's more often before low than high vowels. We suggest that this vowel-based pattern may result when deaf children learn to lower their larynges in response to visible jaw lowering cues. Another child presented with a pattern of more frequent -Po's before front than back vowels, suggesting that she may have expanded her pharynx anteriorly as she attempted to achieve an anterior tongue placement. Two children also clearly used -Po's more frequently for voiced than voiceless stops, possibly resulting from a tendency to use the degree rather than the timing of vocal fold adduction to distinguish voiceless and voiced phonemes. Two of the children were enrolled in a single-subject multiple baseline study to compare the effectiveness of traditional articulation treatment and visual-feedback treatment. The child who was a far less proficient talker demonstrated rapid and sustained change, whereas the better talker demonstrated minimal change with treatment. This study provides evidence that (a) deaf children use speech production strategies quite unlike those of normally hearing children and (b) deviant speech behaviors of deaf children should be treated before they become part of functional phonological systems. This work highlights the need to consider the unique speech behaviors of deaf children, and their reliance on alternate feedback mechanisms, when developing assessment and treatment procedures.

Chronic endotoxemia and endothelium-dependent vasodilation in coronary arteries

Endotoxin acutely decreases the production of nitric oxide, leading to abnormal regulation of coronary vascular tone: however, the effects of chronic endotoxemia on vasomotion are unknown. We therefore tested the hypothesis that chronic, low-level endotoxemia inhibits endothelium-dependent vasodilation. Rabbits were continuously infused with a subclinical dose of Escherichia coli endotoxin (.6 microgram/24 h, intraperitoneal) or saline for 5 wk. Endotoxin at this concentration elicited no significant sustained pyretic or hemodynamic responses. Both endothelium-dependent and independent vasomotor responses were determined in coronary arteries (250-500 mu). Vasorelaxation in response to acetylcholine, but no adenosine diphosphate (ADP), was significantly enhanced in endotoxin-challenged animals (EC50 = 62.6 +/- 11.1 nM, control vs. 33.97 +/- 5.7 nM, endotoxin-challenged; p < .05). Vasoconstriction to PGF2 alpha, but not KCl, was significantly decreased in endotoxin-challenged animals. These results indicate that endothelium-dependent and independent vasomotor responses are altered during chronic endotoxemia and are due, in part, to alterations in signal-transduction mechanisms specific for certain types of receptors.

Neutrophil taurine in psoriasis

Neutrophil taurine was measured in 30 subjects presenting with chronic stable plaque-type psoriasis. The taurine concentration expressed per 5 x 10(6) cells was significantly lower (p < 0.002) in these subjects compared to neutrophil taurine measured in 20 control subjects. In view of increasing evidence proposing possible roles for taurine in maintaining normal neutrophil function coupled with previously observed anti-inflammatory effects of taurine in vitro, an assessment of possible roles of taurine in the aetiology of psoriasis is discussed.

Facilitative affiliation: nurse-client interactions that enhance healing

Facilitative affiliation is a new concept developed to capture the essence of effective nurse-client interactions, regardless of the client population or the practice setting. This concept has been synthesized within the theoretical framework of Modeling and Role-Modeling. Defining attributes have been identified as (a) presence, (b) assessment of needs based on the client's self-care knowledge and perceived resources, (c) creative individualized interventions, (d) selective normative disregard, (e) mutual trust, (f) nurturance, and (g) advocacy: Facilitative affiliation is defined as any nurse-client interaction in which the nurse assesses the client's needs based on that individual's self-care knowledge and perceived resources and creates individualized interventions based on those identified needs. The relationship is then characterized by availability, nurturance, and advocacy on the part of the nurse and a sense of mutual trust between the client and the nurse. Several client outcomes have been posited including that of enhanced healing.

Formaldehyde replaces glutaraldehyde in porcine bioprosthetic heart valves

BACKGROUND AND AIMS OF THE STUDY

In the production of porcine bioprostheses, the initial glutaraldehyde treatment is often followed by a short incubation in formaldehyde to ensure sterility of the valve. It is assumed that the glutaraldehyde cross links are stable and that the formaldehyde step does not alter the glutaraldehyde incorporated. The objective of this study was to determine whether the formaldehyde interacts with the tissue to cause changes in the glutaraldehyde composition.

MATERIALS AND METHODS

Two methods of tissue treatment were investigated: (i) fresh porcine leaflet tissue was treated with glutaraldehyde, followed by storage in formaldehyde, (ii) tissue processed in glutaraldehyde and transferred to formaldehyde for six hours was returned to glutaraldehyde for storage. The content of the two aldehydes was estimated by high performance liquid chromatography (HPLC), using an adaptation of the method developed by Hughes et al, which measures the acid labile Schiff bases formed between the collagen and the aldehyde.

RESULTS

The initial content of glutaraldehyde in the tissue declined from 63 +/- 10 nmol/mg dry weight to 21 +/- 4 nmol/mg dry weight when the leaflets were placed in formaldehyde for 24 hours. The initial uptake of formaldehyde was 800 +/- 144 nmol/mg dry weight after 24 hours and this declined to 370 +/- 33 nmol/mg dry weight over a 16 week period of storage in formaldehyde. By this stage, the level of glutaraldehyde had decreased to 2.4 +/- 0.2 nmol/mg dry weight. There was a sharp decline in the glutaraldehyde concentration from 89 +/- 6 nmol/mg dry weight to 14 +/- 1 nmol/mg dry weight when the tissue was placed in 4% formaldehyde solution for six hours. The formaldehyde uptake was 770 +/- 54 nmol/mg dry weight. After return to 0.625% glutaraldehyde solution the formaldehyde concentration declined whilst the glutaraldehyde concentration initially increased.

CONCLUSIONS

These results show that the formaldehyde reacts with the epsilon amino groups of lysine which had not reacted with glutaraldehyde, probably for steric reasons; and that formaldehyde replaces some glutaraldehyde in the tissue by a mass action effect. The tissue concentration of both aldehydes subsequently declined over the study period.

Nitric oxide synthase inhibition during experimental sepsis improves renal excretory function in the presence of chronically increased atrial natriuretic peptide

OBJECTIVE

To test whether renal excretory function decreases after nitric oxide synthase inhibition during experimental hyperdynamic sepsis.

DESIGN

Prospective, randomized, controlled animal trial.

SETTING

Research laboratory at a large university medical center.

SUBJECTS

Chronically instrumented Merino breed ewes (n = 18).

INTERVENTIONS

Continuous infusion of Escherichia coli endotoxin (10 ng/kg/min) for the experimental period of 32 hrs. One group received a bolus of the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (25 mg/kg), after 24 hrs, and the remaining sheep were given the carrier, sodium chloride 0.9%.

MEASUREMENTS AND MAIN RESULTS

The sheep developed a hyperdynamic cardiovascular response characterized by a decrease in systemic vascular resistance index (p < .05), and an increased cardiac index (p < .05) by 24 hrs. The sheep retained fluid, with creatinine clearance decreasing in the presence of chronically increased atrial natriuretic peptide. After the administration of N omega-nitro-L-arginine methyl ester, systemic vascular resistance index and cardiac index returned to baseline values, fluid balance normalized, and glomerular filtration rate increased (p < .05), while the control animals continued to retain fluid and their creatinine clearance continued to decrease. The concentrations of atrial natriuretic peptide did not differ significantly between groups after N omega-nitro-L-arginine methyl ester administration.

CONCLUSIONS

In this ovine model of experimental hyperdynamic sepsis, renal excretory function decreases in the presence of chronically increased concentrations of atrial natriuretic peptide. Administration of the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester, reverses the vasodilatory state, thereby improving fluid balance and glomerular filtration.

Multiple keratoses and squamous carcinoma after PUVA treatment of vitiligo

PUVA is known to be carcinogenic when used in the treatment of psoriasis. To date skin cancer has not been demonstrated after PUVA treatment of vitiligo. We report a patient in whom multiple squamous cell carcinomata and keratoses developed in vitiligo areas after a prolonged course of PUVA. PUVA therapy of vitiligo induces repigmentation of affected skin in some patients. An increased frequency of cutaneous neoplasms in depigmented areas is a potential hazard, as in these sites the photoprotective effect of melanin is lacking.

The horizon-ratio relation as information for relative size in pictures

The horizon-ratio relation was found to be an effective source of information for relative size in pictures under some conditions: when the difference in image size of depicted "same real size" objects was not too great (Experiment 1), and when the horizon line was not too high or too low in the picture (Experiment 2). The latter finding seemed to be linked to the observers' identification of the horizontal line as the horizon (and not as the edge of a finite surface). In addition, individual patterns of response were remarkably systematic even in the absence of a horizon, or any other pictorial information, (Experiment 3). It is suggested that in this case observers imposed a horizon on the picture on which to base their relative size judgments, possibly based on the observer's own eye level or on the content of the picture. It is concluded that although the horizon-ratio relation provides the same kind of information as that available in the optic arrays from real scenes, pictorial information requires the satisfaction of additional constraints in order to be fully effective.

A new animal model for abdominal aortic aneurysms:initial results using a multiple-wire stent

OBJECTIVES

The effect of a plain 48-wire self-expanding flexible stent (Wallstent-Schneider (Europe) AG) on abdominal aortic aneurysms has been studied in a new animal model.

METHODS

Aneurysms were created by interposing fusiform segments of glutaraldehyde-tanned bovine internal jugular vein into the infrarenal aortas of 12 Large White pigs. The first six pigs were assessed after 6 weeks by ultrasonography and arteriography; they were then sacrificed for pathological examination. Endovascular placement of the stents, 2 weeks after aneurysm creation, was performed under arteriographic control in the next six pigs. These pigs were assessed by ultrasonography and arteriography 6 weeks after stenting; they were then sacrificed for pathological examination.

RESULTS

At 6 weeks the aneurysms in the first group were pulsatile with partial endothelialisation and no mural thrombus. Placement of the stent in the second group was accomplished easily. Stenting resulted in an immediate reduction in wall pulsatility of all aneurysms and thrombosis of the excluded aneurysm sac occurred in three cases. In the other three cases the pulse pressure in the sac was reduced. In all cases there was a significant reduction in maximum aneurysm diameter when measured 6 weeks after stenting.

CONCLUSIONS

A pulsatile, non-thrombogenic aortic aneurysm model approaching human dimensions has been successfully developed for the study of endoprostheses prior to their clinical use. Endovascular placement of a plain, multiple-wire Wallstent was associated with reductions in aneurysm pulsatility, pulse pressure within the sac and maximum aneurysm diameter over the study period. Stenting was associated with thrombosis of the excluded aneurysm sac in 50% of cases.

A comparison of twice-weekly MPD-PUVA and three times-weekly skin typing-PUVA regimens for the treatment of psoriasis

The most frequent PUVA treatment regimen in current use is three times weekly, using skin typing to estimate the starting dose. Recently, it was suggested that twice-weekly treatment, using the minimal phototoxic dose (MPD) to calculate suberythemal starting doses of UVA, achieved similar clearance rates with fewer treatments and a lower cumulative UVA dose. We have carried out a trial on 83 patients, comparing twice-weekly MPD-PUVA with three times-weekly skin typing-PUVA, in order to test this hypothesis. Although clearance rates were comparable between the two regimens, there was no overall significant difference in the number of treatments or in the cumulative UVA doses at clearance. However, for patients with skin types I and II the cumulative UVA dose was significantly higher using the twice-weekly MPD regimen (70.0 J/cm2 vs. 55.8 J/cm2; P < 0.05). Our results do not confirm that there is a reduction in cumulative UVA dosage with twice-weekly MPD-PUVA.

Survival, metastasis and recurrence of oral cancer in relation to pathological features

The outcome of 123 patients with squamous cell carcinoma of the oral/oropharyngeal mucosa treated by primary radical surgery and simultaneous neck dissection and followed up for a maximum of 5 years is reported and related to the pathological features of the tumour. Actuarial survival analysis showed the overall 1-year survival probability was 84%, falling to 69% at 2 years, and 65% at 5 years. For patients without lymph node metastasis, the corresponding survival probabilities were 95%, 86% and 86%, respectively; and for patients with metastasis, 71%, 52% and 44%, respectively. In all, 30 patients (24%) died of their oral cancer; 16 (13%) of local recurrence, 10 (8%) of regional recurrence and 4 (3%) of systemic metastases. In addition to lymph node metastasis, survival was related to the site and stage of the primary tumour, histological pattern of invasion, status of the resection margins and, for patients with metastasis, the number and anatomical level of positive nodes and the presence and extent of extracapsular spread. These pathological features are important indicators of tumour behaviour and should be incorporated into protocols for assessment of prognosis.

Cyclosporin-responsive hidradenitis suppurativa

Hidradenitis suppurativa, a chronic inflammatory condition of the apocrine gland follicles, may rarely be complicated by pyoderma gangrenosum (PG). We report such a case, in which the immunosuppressant cyclosporin A (CyA) was given to treat PG and a dramatic improvement occurred in the patient's intractable perineal HS.

Cutaneous lupus erythematosus--a study of clinical and laboratory prognostic factors in 65 patients

An eleven year review of patients presenting with cutaneous lupus erythematosus (LE) was made in order to determine the frequency of change from discoid LE (DLE) to systemic LE (SLE) and to identify clinical and laboratory prognostic factors. Three of fifty-six (5.4%) patients with DLE progressed to SLE after 1, 13 and 34 years respectively. They had a progressive rash and persistent abnormalities in their full blood count, erythrocyte sedimentation rate, antinuclear antibody and serum immunoglobulins prior to the development of SLE. We recommend that regular longterm monitoring of these indices should be carried out in patients presenting with DLE.

Miller Fisher syndrome and anti-GQ1b antibodies

A case is presented of Miller Fisher syndrome in a 77-year-old woman. The diagnosis was confirmed by the presence of serum IgG antibody to ganglioside GQ1b. Miller Fisher syndrome, although uncommon, enters the differential diagnosis of brainstem stroke.

Retinoic acid stimulates glucose transporter expression in L6 muscle cells

Factors that regulate the tissue specific and developmental expression of the GLUT4 gene, whose transcribed protein is primarily responsible for mediating insulin stimulated glucose transport, are poorly defined. In this study we examined the effects of retinoic acid, a circulating factor that can promote cellular differentiation, on glucose uptake and glucose transporter expression in cultured L6 muscle cells. At the myoblast stage, treatment with 1 microM retinoic acid for 24 h increased both 1 h and 8 h insulin stimulated uptake of 2-deoxyglucose by more than twofold. A dose and time dependent effect of retinoic acid on 8 h insulin stimulated 2-deoxyglucose uptake was observed at both the myoblast and myocyte stage. Comparatively little effect from retinoic acid treatment was found on basal uptake at either stage. In myoblast cells, retinoic acid increased the content of GLUT4 mRNA in a dose and time dependent manner, an effect that was partially attenuated by insulin. In myocytes retinoic acid increased GLUT4 mRNA levels to 2.3 times basal. Nuclear run-on studies indicate that the increased GLUT4 mRNA represents enhanced transcriptional activity. The results suggest a role for retinoic acid in regulation of expression of the GLUT 4 gene in muscle cells.

Pyoderma gangrenosum, erythema elevatum diutinum and IgA monoclonal gammopathy

A patient with erythema elevatum diutinum (EED) developed pyoderma gangrenosum (PG). Investigation revealed an IgA kappa monoclonal gammopathy. Previous reports of PG in association with EED are reviewed and the spectrum of the neutrophilic dermatoses discussed.