Hippocampal atrophy in normal aging. An association with recent memory impairment

OBJECTIVE: To estimate the prevalence of radiographically detectable hippocampal atrophy (HA) in a normal aging sample and to test whether such atrophy is associated with memory dysfunction. DESIGN: One hundred fifty-four medically healthy and cognitively normal elderly persons (aged 55 to 88 years) received magnetic resonance imaging and/or computed tomographic scans designed to identify HA. One hundred forty-five of these subjects also underwent psychometric tests of memory function. Multivariate analyses of variance were used to evaluate differences in memory performance between subjects with and without HA. SETTING: This study was conducted at a research clinic for the investigation of age-associated neuropsychological and neuroradiologic changes. PARTICIPANTS: Based on the following criteria, 154 subjects were consecutively selected from a larger group of elderly research volunteers participating in a study of normal aging: age of 55 years or greater; Global Deterioration Scale score of 2 or less; and Mini-Mental State examination score of 28 or greater. Subjects with evidence for significant medical, psychiatric, or neurologic disease were excluded. MAIN OUTCOME MEASURES: Outcome measurements included individual psychometric test scores and computed tomographic-magnetic resonance imaging hippocampal atrophy ratings. RESULTS: Nearly 33% of the subjects had radiographic evidence for HA. The prevalence of HA increased significantly with age and was more common in male than female subjects. After controlling for age, level of education, and vocabulary, subjects with HA were found to perform more poorly on tests of recent (secondary) verbal memory when compared with subjects without HA (P < .01). No significant differences were found for tests of immediate (primary) memory. CONCLUSION: We conclude that HA is a common accompaniment of normal aging and is associated with mild memory impairment. Additional research is needed to determine whether HA constitutes a significant risk for future dementia.     

Participation in continuing professional education in nursing: findings of an interview study

The evidence suggests that enrolled nurses and those working part-time and on night duty consistently attend less continuing professional education than their more senior, full-time and day duty colleagues. This was substantiated in the findings of this study which also highlighted the paucity of opportunities for continuing education among unqualified practitioners. In the light of recent developments within the health services, this inequitable provision of continuing professional education to all nursing practitioners will need to be addressed and resolved. Continuing professional education provided on an arbitrary and random basis will not afford maximum positive outcomes for clients, the service and practitioners and has the potential to increase the levels of frustration among disadvantaged groups of nursing staff.     

Enzymatic preparation of heparin oligosaccharides containing antithrombin III binding sites

Two new oligosaccharides were prepared from heparin by its partial depolymerization using heparin lyase I (EC 4.2.2.7) in an attempt to prepare oligosaccharides having intact antithrombin III binding sites. The oligosaccharides were purified by chromatography on the basis of both size and charge and demonstrated a high level of purity by capillary electrophoresis. One- and two-dimensional 1H NMR spectroscopy at 500 MHz revealed the structure of each oligosaccharide. The octasaccharide and decasaccharide are DeltaUAp2S(1-->4)-alpha-DGlcNpS6S(1-->4)-alpha-L-IdoAp (1-->4)-alpha-D -GlcNpAc6S(1-->4)-betaD-GlcAp(1-->4)-alpha-D-GlcNpS 3S6S(1-->4)-alpha- L-IdoAp2S(1-->4)alpha-D-GlcNpS6S (where DeltaUAp is 4-deoxy-alpha-L-threo-hex-enopyranosyluronic acid, GlcNp is 2-amino-2-deoxy-glucopyranose, GlcAp is glucopyranosyluronic acid, S is sulfate and Ac is acetate) and DeltaUAp2S(1-->4)-alpha-D-GlcNpS6S(1-->4)-alpha-L-IdoAp++ +(1-->4)-alpha- D-GlcNpAc6S (1-->4)-beta-D-GlcAp(1-->4)-alpha-D-GlcNpS3S6S(1-->4)-alpha- L-IdoAp2S (1-->4)-alpha-D-GlcNpS6S(1-->4)-alpha-L-IdoAp2S(1-->4)-alpha -D-GlcNpS 6S, respectively. A hexasaccharide containing a similar structural motif to that found in the antithrombin III binding site and having greatly reduced anticoagulant activity was also isolated. The structure of the hexasaccharide is DeltaUAp2S(1-->4)-alpha-D-GlcNpAc6S(1-->4)-beta-D-GlcAp++ +(1-->4)-alpha- D-GlcNpS3S6S(1-->4)-alpha-L-IdoAp(1-->4)-alpha-D-GlcNpS6S . The octasaccharide and decasaccharide correspond to the predominant structural motif found in porcine intestinal mucosal heparin. Sufficient quantities of the decasaccharide were obtained to examine its interaction with antithrombin III using microtitration calorimetry. This decasaccharide bound to antithrombin III with similar avidity as heparin and showed comparable anticoagulant activity, as determined using an antithrombin III dependent anti-factor Xa assay. Interestingly, while both decasaccharide and heparin bound to antithrombin with nanomolar affinity, very little heat of binding was observed.     

The heterogeneity of cell populations by the cytochemical characteristics of the cellular chromatin

Cell heterogeneity of cytochemical characteristics of chromatin in the norm and after provocative factors in vitro (a heating at 45 degrees C, X-irradiation and joint actions of heating and X-ray irradiation) was investigated in the peripheral blood mononuclear cells of sheep and mouse, the lymphoid cell populations of the murine bone marrow, spleen and thymus. As a criterion of cytochemical heterogeneity were used the distinctions in the rate of staining of cell nuclei with DNA-specific dyes, that was registered by means of measurement of coefficient variation of the DNA-histogram basis peak, with a flow cytometry. Heterogeneity of cytochemical characteristics are dealt with showed a variability of spatial organization of interphase nuclei of single cells. The provocative factors bring about a decrease in the level of the cytochemical characteristics heterogeneity in the sheep mononuclear cells. In the murine cell populations studied no such equalizing of the marker of variability was revealed.     

Growth hormone secretion, puberty and adult height after cranial irradiation with 18 Gy for leukaemia

The dose of prophylactic cranial irradiation given to patients for acute lymphoblastic leukaemia has been decreased from 24 to 18 Gy, but the beneficial effect of this decrease on growth is controversial. This study compares the growth hormone (GH) secretion and growth of 35 patients (20 boys) given 18 Gy at 3.7+/-0.3 (SE) years, and routinely evaluated 5.4+/-0.4 years after irradiation to define the indications for GH treatment in these patients. Of these, 63% had a low GH peak (< 10 microg/l) after one (22 cases) or two (17 cases) stimulation tests. The plasma concentrations of insulin-like growth factor I and its GH-dependent binding protein were normal for age in all but two cases. The height changes between irradiation and evaluation were correlated with the GH peaks (P < 0.03) and were concordant, except in patients with early puberty. This occurred in 16 patients including all 12 girls irradiated before 4 years of age. A significant (P < 0.03) reduction in height (SD) between irradiation and adult height occurred in untreated GH-deficient patients (-1+/-0.3, n=6), but not in GH-deficient patients given GH (-0.6+/-0.3, n=8) or in those with normal GH peak (-0.4+/-0.3, n=7). CONCLUSION: In children irradiated for acute lymphoblastic leukaemia, GH deficiency is frequent after 18 Gy but its impact on adult height is smaller than after higher doses. We suggest that the indications for gonadotropin releasing hormone analogue therapy should be broad in patients with early or rapidly progressing puberty and those for GH therapy in those patients with a below average constitutional height before irradiation.     

Potato gun ocular injury

PURPOSE: This study aimed to identify a dangerous new weapon capable of causing damage to the ocular and periocular regions. METHODS: The authors report two patients who had penetrating ocular injury in the past year because of homemade recreational potato guns. RESULTS: In one 14-year-old boy, projectiles from the firing of a potato gun resulted in orbital and cranial injuries that were life threatening with widespread fractures, marked disruption of facial structures, a cerebrospinal fluid fistula requiring bifrontal surgical repair, and loss of one eye. In a separate accident with a different potato gun, a 14-year-old boy who was wearing glasses at the time of injury had a sight-threatening perforating corneal laceration. CONCLUSION: Practitioners must be aware of the existence of these new, homemade unregulated devices. Information about the use and construction of these guns is widespread on the Internet, but no injuries resulting from these guns currently are documented in the medical literature.     

Ultrasonographically-guided fine-needle aspiration cytology in the diagnosis of colonic lesions

BACKGROUND: The use of fine-needle aspiration cytology (FNAC) in the diagnosis of colonic lesions was investigated. METHODS: Some 22 patients (median age 71 years) with a colonic lesion identified on abdominal ultrasonography underwent ultrasonographically-guided FNAC using a 21-G needle. The sample was checked immediately by a cytopathologist for adequacy. RESULTS: Eighteen patients had colonic carcinoma; aspiration cytology detected malignant epithelial cells consistent with colonic carcinoma in 17 patients and severely dysplastic cells in one patient. The sensitivity and specificity of ultrasonographically-guided FNAC in the diagnosis of colonic carcinoma was 94 and 100 per cent respectively. The remaining four patients had a diagnosis of ileocaecal tuberculosis, ileocaecal Crohn's disease, and metastatic adenocarcinoma in the liver with no identifiable primary (two patients). One demonstrated granulomata, grew acid-fast bacilli and the patient was treated for tuberculosis. One had inflammatory cells and the patient was found to have Crohn's disease on histology. The remaining two patients had confirmed metastatic adenocarcinoma in the liver on aspiration cytology but suspected colonic lesions were found to be benign on cytological examination and no primary lesion was subsequently demonstrated. There were no complications of FNAC and patients complained of minimal discomfort. There has been no evidence of tumour recurrence with a median follow-up of 12 (range 1-25) months. CONCLUSION: Ultrasonographically-guided FNAC is a valid method for the diagnosis of colonic tumours.     

Limitations to exercise- and maximal insulin-stimulated muscle glucose uptake

The hypothesis of this investigation was that insulin and muscle contraction, by increasing the rate of skeletal muscle glucose transport, would bias control so that glucose delivery to the sarcolemma (and t tubule) and phosphorylation of glucose intracellularly would exert more influence over glucose uptake. Because of the substantial increases in blood flow (and hence glucose delivery) that accompany exercise, we predicted that glucose phosphorylation would become more rate determining during exercise. The transsarcolemmal glucose gradient (TSGG; the glucose concentration difference across the membrane) is inversely related to the degree to which glucose transport determines the rate of glucose uptake. The TSGG was determined by using isotopic methods in conscious rats during euglycemic hyperinsulinemia [Ins; 20 mU/(kg. min); n = 7], during treadmill exercise (Ex, n = 6), and in sedentary, saline-infused rats (Bas, n = 13). Rats received primed, constant intravenous infusions of trace 3-O-[3H]methyl-D-glucose and [U-14C]mannitol. Then 2-deoxy-[3H]glucose was infused for the calculation of a glucose metabolic index (Rg). At the end of experiments, rats were anesthetized, and soleus muscles were excised. Total soleus glucose concentration and the steady-state ratio of intracellular to extracellular 3-O-[3H]methyl-D-glucose (which distributes on the basis of the TSGG) were used to calculate ranges of possible glucose concentrations ([G]) at the inner and outer sarcolemmal surfaces ([G]im and [G]om, respectively). Soleus Rg was increased in Ins and further increased in Ex. In Ins, total soleus glucose, [G]om, and the TSGG were decreased compared with Bas, while [G]im remained near 0. In Ex, total soleus glucose and [G]im were increased compared with Bas, and there was not a decrease in [G]om as was observed in Ins. In addition, accumulation of intracellular free 2-deoxy-[3H]glucose occurred in soleus in both Ex and Ins. Taken together, these data indicate that, in Ex, glucose phosphorylation becomes an important limitation to soleus glucose uptake. In Ins, both glucose delivery and glucose phosphorylation influence the rate of soleus glucose uptake more than under basal conditions.