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Biomedical subjects

M Berry

Publications and source records attributed to M Berry.

At least 91 records · Page 5Linked to original sources
PubMed1997

Hyperopia correction by noncontact holmium:YAG laser thermal keratoplasty: U.S. phase IIA clinical study with 2-year follow-up.

PURPOSE: This study was performed to determine the long-term efficacy, safety, and stability of noncontact holmium:yttrium aluminum garnet (Ho:YAG) laser thermal keratoplasty (LTK) for correction of low-to-moderate hyperopia. METHODS: The authors treated 1 eye each of 28 patients for correction of low-to-moderate hyperopia (up to +3.88 diopters [D] refractive error) using the Sun 1000 Corneal Shaping System (Sunrise Technologies, Inc., Fremont, CA). Treatments were performed with one or two rings of eight spots per ring with centerline diameters of 6 mm (one ring) or 6 and 7 mm (two rings), ten pulses of laser light at 5-Hz pulse repetition frequency, and pulse energies ranging from 208 to 242 mJ. Follow-up was 2 years. RESULTS: At 2 years after surgery, uncorrected distance visual acuity was improved by 1 or more lines of Snellen visual acuity in 19 (73%) of 26 of the treated eyes. The mean lines gained was 2.5 +/- 2.2/3.3 +/- 2.7 for one- and two-ring treatment groups, respectively. The mean change in spherical equivalent of the subjective manifest refraction was -0.53 +/- 0.33 D/-1.48 +/- 0.58 D for one- and two-ring treatment groups. Regression between 1 and 2 years was 0.01 D and 0.16 D, respectively. In the one-ring treatment group (18 eyes), 13 eyes (72%) had refractive corrections (range, -0.38 to -1.13 D), and 5 eyes (29%) were unchanged (within +0.25 D) relative to their preoperative measurements. In the two-ring treatment group, all eight eyes (100%) had reductions in their hyperopia (range of corrections, -0.38 to -2.25 D). None of the eyes lost two or more lines of spectacle-corrected distance visual acuity. There were no sight-threatening complications. CONCLUSIONS: This initial U.S. clinical study indicates that noncontact laser thermal keratoplasty treatment of low hyperopia is safe and produces modest but persistent corrections with 2-year follow-up. Expanded studies of this treatment method are warranted.

Adult↗
PubMed1997

The relationship between developing oligodendrocyte units and maturing axons during myelinogenesis in the anterior medullary velum of neonatal rats.

Myelinogenesis was investigated in whole-mounted anterior medullary vela from rats aged postnatal day (P) 10-12, using double immunofluorescence labelling with Rip and anti-neurofilament 200 (NF200) antibodies, to identify oligodendrocytes and axons, respectively. A number of discrete phases of maturation of oligodendrocyte units were recognised. (1) Promyelinating oligodendrocytes co-expressed Rip and Myelin basic Protein and formed axonal associations, prior to ensheathment. (2) Transitional oligodendrocytes contained both ensheathing and non-ensheating processes. (3) Myelinating oligodendrocytes were established after a period of remodelling (in which non-ensheathing processes were lost), appearing as oligodendrocyte unit morphological phenotypes with a definitive number of incipient myelin sheaths. (4) Maturation of myelinating oligodendrocytes was defined as the establishment of internodal sheath lengths and the redistrubution of myelin basic protein from the cell somata and radial processes into the myelin sheaths only. Myelination was probably related to the maturational state of the axons, since it was initiated when the latter had attained a critical diameter of between approximately 0.2 and 0.4 micron, coincident with the expression of NF200. Oligodendrocyte differentiation and myelination of the AMV were asynchronous and multifocal, and at P10: (1) axons which were destined to be of the largest calibre in the adult AMV were already myelinated by early developing oligodendrocytes, whilst those which were destined to be the smallest calibre in the adult were unmyelinated, but ultimately became ensheathed by late developing oligoendrocytes; (2) axons were sequentially ensheathed by early developing myelinating oligodendrocytes and late developing promyelinating oligodendrocytes; (3) all axons were small calibre; (4) oligodendrocyte units exhibited polymorphism. Thus, the development of oligodendrocyte morphological phenotypes was not related solely to either the physical dimension of axon calibre at the time of ensheathment, nor oligodendrocyte birth dates.

Animals↗
PubMed1997

Unusual computed tomography appearance of Castleman disease.

A case is presented here of Castleman disease in an uncommon location. Ultrasonography demonstrated a large hypoechoic mass with multiple vascular channels. On computed tomography, the lesions with a nodular contour were located lateral to the carotid sheath on the right side, and demonstrated a variegated enhancement pattern.

Adult↗
PubMed1997

Spatial and temporal changes in the insulin-like growth factor (IGF) axis indicate autocrine/paracrine actions of IGF-I within wounds of the rat brain.

A precise role for insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and IGF-receptors (IGF-Rs) in damaged central nervous system (CNS) tissue has not been elucidated, although their expression in the ischemic brain has been demonstrated. However, little is known of IGF responses after CNS trauma. In this study, we have used ribonuclease protection assay, in situ hybridization, and immunohistochemistry to demonstrate that IGF-I, IGFBPs, and IGF-1R expression alters in response to a penetrating CNS injury. Within penetrant cerebral wounds in the acute phase of the response (1-7 days post lesion; dpl), increased levels of IGF-I, IGFBP-1, -2, -3, -6, and IGF-1R protein were localized to injury responsive astrocytes, neurons and cells of the monocyte lineage. IGF-I, IGFBP-2, and 3 showed a congruency in sites of messenger RNA (mRNA) and peptide expression, with IGF-I and IGFBP-2 mRNA expression predominating. IGF-I, IGFBP-1, and IGFBP-3 protein were also associated with the microvascular endothelium, which was accompanied by increased levels of IGFBP-3 mRNA. These early changes in IGFBP expression probably facilitate IGF-I action. Later in the wounding response (7-14 dpl), the expression of IGFBP-4 and IGFBP-5 peaked within astrocytes and neurons, with IGFBP-5 mRNA being specifically localized to the glia limitans within the wound, suggesting an inhibitory role for these proteins, down-regulating the effects of IGF-I chronically. Our evidence suggests that within penetrating CNS wounds, IGF-I acts in an autocrine/paracrine manner to regulate cellular responses, with its spatial and temporal availability being modulated by the differential presence of stimulatory vs. inhibitory IGFBPs.

Animals↗
PubMed1997

Birth weight reduction associated with residence near a hazardous waste landfill.

We examined the relationship between birth weight and mother's residence near a hazardous waste landfill. Twenty-five years of birth certificates (1961-1985) were collected for four towns. Births were grouped into five 5-year periods corresponding to hypothesized exposure periods (1971-1975 having the greatest potential for exposure). From 1971 to 1975, term births (37-44 weeks gestation) to parents living closest to the landfill (Area 1A) had a statistically significant lower average birth weight (192 g) and a statistically significant higher proportion of low birth weight [odds ratio (OR) = 5.1; 95% confidence interval (CI), 2.1-12.3] than the control population. Average term birth weights in Area 1A rebounded by about 332 g after 1975. Parallel results were found for all births (gestational age > 27 weeks) in Area 1A during 1971-1975. Area 1A infants had twice the risk of prematurity (OR = 2.1; 95 CI, 1.0-4.4) during 1971-1975 compared to the control group. The results indicate a significant impact to infants born to residents living near the landfill during the period postulated as having the greatest potential for exposure. The magnitude of the effect is in the range of birth weight reduction due to cigarette smoking during pregnancy.

Adult↗
PubMed1997

Blood glucose concentration influences postprandial fullness in IDDM.

OBJECTIVE: Upper gastrointestinal (GI) symptoms and delayed gastric emptying both occur frequently in patients with long-standing IDDM, but the relationship between them is relatively weak. Recent studies in normal subjects have indicated that blood glucose concentration may increase the perception of sensations arising from the upper GI tract. The purpose of this study was to examine the relationships among postprandial fullness, the rate of gastric emptying, and blood glucose concentration in IDDM patients. RESEARCH DESIGN AND METHODS: We studied measurements of gastric emptying, blood glucose concentrations, cardiovascular autonomic nerve function, upper GI symptoms, and postprandial hunger and fullness in 40 IDDM patients (16 men, 24 women). ages 19-63 years. Gastric emptying of solids and liquids was measured scintigraphically, upper GI symptoms were measured by questionnaire immediately before ingestion of the test meal, and fullness and hunger were measured by visual analog scales every 15 min. Blood glucose concentrations were measured at -5, 30, 60, 90, and 120 min. RESULTS: Solid gastric emptying was delayed in 58% of the patients, and both solid and liquid gastric emptying were slower (P < 0.05) in women than in men. The score for upper GI symptoms was not significantly related to gastric emptying. In contrast, postprandial fullness, but not hunger, was related to the amount of solid (r = 0.36, P < 0.05) but not liquid in the stomach. Both before (r = 0.39, P < 0.05) and after (r = 0.47, P < 0.01) the meal, fullness was related to blood glucose concentration. Postprandial fullness was also related to autonomic nerve dysfunction (r = 0.39, P < 0.05). Multiple regression analysis confirmed that blood glucose concentration, the rate of solid gastric emptying, and autonomic nerve dysfunction were independent determinants of postprandial fullness, together accounting for 47% of the variance. CONCLUSIONS: These observations demonstrated that, in IDDM, postprandial fullness is influenced by blood glucose concentration, the rate of solid gastric emptying, and autonomic nerve function.

Adult↗
PubMed1997

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Computer Communication Networks↗
PubMed1997

Surgical treatment of iatrogenic tracheal lacerations.

Traumatic and iatrogenic injuries of the trachea are uncommon. These injuries which are usually managed by surgery are associated with a high morbidity and mortality. In case of suspected lacerations, bronchoscopy remains the diagnostic procedure of choice. We present two unusual iatrogenic tracheal lacerations due to endotracheal stenting and intubation which were managed by primary suture with coverage of the suture line.

Adult↗
PubMed1996

Cholesterol-lowering intervention program. Effect of the step I diet in community office practices.

BACKGROUND: A randomized study was conducted to test the feasibility of cholesterol lowering in physician office practices using the National Cholesterol Education Program Adult Treatment Panel 1 guidelines. METHODS: Twenty-two physician practices in phase 1 and 23 in phase 2 were recruited from communities in Western Pennsylvania and West Virginia. These physicians treated a total of 450 adults in phase 1 (190 men and 260 women) and 480 adults in phase 2 (184 men and 296 women) with hypercholesterolemia. Three models (Usual Care [phase 1], Office Assisted [phase 2], and Nutrition Center [phase 2]) for implementing the National Cholesterol Education Program Adult Treatment Panel 1 guidelines were tested over an 18-month period. The baseline serum cholesterol levels were as follows: 6.51 mmol/L (252 mg/dL) in the Usual Care Model; 6.80 mmol/L (262 mg/dL) in the Office Assisted Model; and 6.96 mmol/L (269 mg/dL) in the Nutrition Center Model. RESULTS: In the patients who were not taking lipid-lowering medication, the mean cholesterol response was significantly different between the 3 models (P < .01). Serum cholesterol levels declined by 0.14 mmol/L (5.4 mg/dL) in the Usual Care Model; by 0.31 mmol/L (12 mg/dL) in the Office Assisted Model; and by 0.54 mmol/L (20.9 mg/dL) in the Nutrition Center Model. Two factors-length of time to follow-up measurement and change in weight-were independently related to cholesterol response across all models. African Americans demonstrated a significantly smaller response than whites in the Usual Care Model, while men demonstrated greater declines in serum cholesterol levels than women in the Office Assisted Model. Patient satisfaction was very favorable in both enhanced conditions; however, those treated in the the Nutrition Center Model were more satisfied (P < .05) with program components. CONCLUSIONS: The impact of nutrition intervention delivered through physician practices on serum cholesterol levels is less than clinically desirable, and new approaches with more aggressive therapy should be tested and implemented.

Anticholesteremic Agents↗
PubMed1996

Role of the duplicated CCAAT box region in gamma-globin gene regulation and hereditary persistence of fetal haemoglobin.

Hereditary persistence of fetal haemoglobin (HPFH) is a clinically important condition in which a change in the developmental specificity of the gamma-globin genes results in varying levels of expression of fetal haemoglobin in the adult. The condition is benign and can significantly alleviate the symptoms of thalassaemia or sickle cell anaemia when co-inherited with these disorders. We have examined structure-function relationships in the -117 HPFH gamma promoter by analysing the effect of mutating specific promoter elements on the functioning of the wild-type and HPFH promoters. We find that CCAAT box mutants dramatically affect expression from the HPFH promoter in adult blood but have little effect on embryonic/fetal expression from the wild-type promoter. Our results suggest that there are substantial differences in the structure of the wild-type gamma promoter expressed early in development and the adult HPFH promoter. Together with previous results, this suggests that gamma silencing is a complex multifactorial phenomenon rather than being the result of a simple repressor binding to the promoter. We present a model for gamma-globin gene silencing that has significant implications for attempts to reactivate the gamma promoters in human adults by pharmacological means.

Animals↗
PubMed1996

Transfer of horseradish peroxidase from oligodendrocyte to axon in the myelinating neonatal rat optic nerve: artefact or transcellular exchange?

In this paper we make the surprising observation that intracellular injection of horseradish peroxidase (HRP) into a single myelinating oligodendrocyte also resulted in localised HRP labelling at the nodes of Ranvier of some axons of the unit. It appeared that HRP had been transferred to the nodal axoplasm from the paranodal loops of the HRP-filled oligodendrocyte. Three HRP-filled oligodendrocytes from isolated optic nerves of 14-day-old rats were analysed by serial section electron microscopy, and HRP was observed in the axonal cytoplasm at three of the nodes of Ranvier delineated by one of the cells. At labelled nodes, HRP was of a uniform intensity throughout the nodal axoplasm. Axonal labelling gradually diminished along the paranodal regions and was not evident in the contiguous internodal axoplasm beyond 20 microns from the node. The myelin sheaths, paranodal loops, and axons appeared normal at labelled nodes, and the paranodal loops and astrocyte perinodal processes adjacent to those of the HRP-filled oligodendrocyte unit did not contain HRP. There was no evidence of extracellular HRP or tissue damage in the surrounding neuropil, and axons neighbouring those enwrapped by the HRP-filled oligodendrocyte did not contain HRP. The possibility that axonal labelling was an artefact of either iontophoretic injection or tissue preparation is discussed. This provocative finding is not definite proof of exchange, but the balance of evidence supports the possibility that there was transcellular exchange of HRP at paranodes between the labelled oligodendrocyte and some of the axons in the unit. The rarity of HRP transfer to axons suggests that it may be a transient or labile event. It is not clear whether oligodendrocyte to axon macromolecular exchange has real physiological and/or pathological significance.

Animals↗