Sustained reduction in child mortality with vitamin A in Nepal.
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Child↗
Biomedical subjects
A Sommer
Publications and source records attributed to A Sommer.
Family history and risk of primary open angle glaucoma. The Baltimore Eye Survey.
OBJECTIVE: Primary open angle glaucoma has been previously associated with a positive family history of glaucoma. We used data from the Baltimore Eye Survey to examine this association. DESIGN: A population-based prevalence survey identified 161 cases of primary open angle glaucoma among 5308 black and white residents of east Baltimore, Md, who were 40 years of age or older. Family history was ascertained by interview and included all first-degree relatives (parents, siblings, and children). RESULTS: Age-adjusted associations of primary open angle glaucoma with a history of glaucoma were higher in siblings (odds ratio [OR] = 3.69) than in parents (OR = 2.17) or children (OR = 1.12). Odds ratios were slightly higher in blacks than in whites, and there was evidence of selection bias, with ORs between two and three times higher for those who had prior knowledge of their glaucoma diagnosis than for those who first received their diagnosis by the study examination (history in siblings OR = 4.72 for those with prior knowledge vs 2.77 for those without). CONCLUSION: Family history is an important risk factor for primary open angle glaucoma, although clinic-based studies are likely to overstate its impact.
Adult↗
Risk factors for the development of glaucomatous visual field loss in ocular hypertension.
OBJECTIVE: To detect characteristics of persons with ocular hypertension that are associated with a higher risk of future glaucomatous field loss. METHODS: Annual examinations of the optic disc, nerve fiber layer, and visual field in 647 persons with bilateral intraocular pressure higher than 21 mmHg and initially normal visual field test results with the Goldmann perimeter. RESULTS: Sixty-eight persons developed a field defect on two consecutive Goldmann visual field tests in at least one eye, while 579 others retained normal fields. Moderate or severe nerve fiber layer atrophy at baseline was associated with a seven to eight times greater risk of development of visual field loss. Attributes that were significantly associated with the incidence of field loss included older age, larger cup-disc ratio, smaller rim-disc area ratio, larger cup asymmetry, presence of disc crescent, and higher intraocular pressure. Characteristics found not to be associated with incidence were gender, race, hypertension, diabetes, refractive error, family history of glaucoma, smoking or alcohol drinking history, and disc area. CONCLUSIONS: Increasing nerve fiber layer atrophy judged by a semiquantitative grading system was associated with increasing risk of development of visual field loss among persons with ocular hypertension. The relationship of the development of field loss to race, myopia, family history of glaucoma, and medical history are more complex than has been presumed.
Adult↗
Race-, age-, gender-, and refractive error-related differences in the normal optic disc.
OBJECTIVE: To determine race-, age-, gender-, and refractive error-related differences in the size and topography of the optic disc in healthy Americans. DESIGN: Population-based study. SETTING: Eastern and southeastern health districts of Baltimore, Md. PARTICIPANTS: A population-based sample of 4877 non-institutionalized black and white individuals aged 40 years or older without evidence of optic nerve disease. MAIN OUTCOME MEASURE: Race-, age-, gender-, and refractive error-related differences in optic disc measurements: disc area, neural rim area, cup area, cup-to-disc ratio, and neural rim area-to-disc area ratio. RESULTS: We analyzed simultaneous stereoscopic optic disc photographs from 3387 (1534 black and 1853 white) of the 4877 healthy individuals using an image analyzer (Topcon Image Analyzer, Topcon Instrument Corporation, Paramus, NJ). A total of 1490 individuals were excluded owing to the absence of good-quality images from either eye. The image analyzer defined the cup margin 150 microns below the surface of the disc margin. On average, blacks had significantly larger disc areas (blacks, 2.94 mm2; whites, 2.63 mm2), larger cup areas (blacks, 1.04 mm2; whites, 0.71 mm2), larger cup-to-disc ratios (blacks, 0.56; whites, 0.49), similar neural rim areas (blacks, 1.90 mm2; whites, 1.92 mm2), and smaller neural rim area-to-disc area ratios (blacks, 0.66; whites, 0.74) compared with whites. There were no age-related differences in any of the disc measurements. Male subjects had 2% to 3% larger optic discs compared with female subjects. No association between refractive error and any of the optic disc measurements studied was detected. CONCLUSIONS: Racial differences in the normal optic disc are present among urban Americans, and these differences must be considered in evaluation of the optic disc for glaucoma and other optic neuropathies. Among the individuals in our study, all of whom were 40 years of age or older, no progressive age-related decline in neural rim area was detectable. Neither gender nor refractive error were associated with any significant differences in the size and topography of the normal optic disc.
Adult↗
Health (care) reform, managed care, and ophthalmology.
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Health Care Reform↗
Benefit of systemically administered rhIGF-I and rhIGF-I/IGFBP-3 on cancellous bone in ovariectomized rats.
The dose-related effects of systemically administered rhIGF-I and rhIGF-I/IGFBP-3 were monitored in the osteopenic rat skeleton at three different sites with cancellous bone: distal femoral metaphysis, epiphysis, and lumbar vertebral bodies. At the age of 16 weeks, rats were bilaterally ovariectomized (OVX) or sham operated (sham) and 8 weeks later divided into the control groups (sham OVX), and OVX groups treated with different doses of rhIGF-I or rhIGF-I/IGFBP-3 for 8 weeks. Fluorescent bone markers were given 9 and 2 days before necropsy. In addition, changes in designated bone sites as a result of ovariectomy alone were evaluated 8 and 16 weeks after surgery. High bone resorption, which dominates the postovariectomy remodeling process, resulted in a loss of cancellous bone at all measured sites. The highest trabecular bone loss was measured in the metaphyses (40%), compared with 22% in the lumbar vertebrae and 16% in the epiphyses. After 8 weeks of treatment with 7.5 mg/kg of rhIGF-I/IGFBP-3, bone formation rates were increased at all sites measured. Increased trabecular thickness was observed at the epiphyses and in the lumbar vertebral bodies. Increased bone resorption was restricted to the metaphyses of the rats that received the highest dose of rhIGF-I or rhIGF-I/IGFBP-3. Both formulations of rhIGF-I increased longitudinal bone growth similarly. This experiment demonstrates site-specific differences in cancellous bone reactions following ovariectomy. Epyphyses showed some advantages for cancellous bone histomorphometry over metaphyses and lumbar vertebral bodies. The data presented confirm the potential of rhIGF-I/IGFBP-3 complex to promote the bone formation process at various bone sites in osteoporotic rat skeleton.
Animals↗
Apoprotein-phospholipid interactions in Lp(a).
Lipoprotein (a) (Lp(a)) and low-density lipoprotein (LDL) are structurally related to each other. Both exhibit identical phospholipid compositions and possess one molecule of apoprotein B-100 (apoB). Lp(a) contains, in addition, apoprotein (a) (apo(a)), which localizes to the particle surface and interacts with the apoB component by non-covalent and covalent forces. Protein-protein interaction is probably interrelated with protein-lipid interaction. Fluorescent analogs of phosphatidylcholine and sphingomyelin were inserted into the surface layer of LDL and Lp(a). The obtained fluorescence data reflecting mobility and distributional heterogeneity of the labeled lipids provided evidence that apo-proteins discriminate between choline phospholipids and preferentially associate with phosphatidylcholine. This effect is enhanced in Lp(a) because of the presence of apolipoprotein (a). Higher affinity for Lp(a) as compared with LDL was also observed with a fluorescent diether analog of phosphatidylcholine in native serum. In contrast, the time-dependent transfer of the same lipid into Lp(a) was slower compared with LDL, probably as a consequence of the more rigid surface of the former lipoprotein.
Apolipoproteins↗
National outcomes of cataract extraction. Retinal detachment and endophthalmitis after outpatient cataract surgery. Cataract Patient Outcomes Research Team.
BACKGROUND: A near-total shift to cataract extraction on an outpatient basis occurred as a result of an administrative ruling by the Health Care Financing Administration. No national study has been conducted to assess the possible effects of that decision on clinical outcomes of surgery. The authors compared the rates of retinal detachment (RD) repair and hospitalization for endophthalmitis after extracapsular cataract extraction (ECCE) (including phacoemulsification) in 1986 and 1987 with those following inpatient cataract extraction in 1984. METHODS: Using the 5% random sample of Medicare beneficiaries, we analyzed the claims of all individuals 66 years of age or older who underwent ECCE by nuclear expression or phacoemulsification in 1986 and 1987. A total of 57,103 patients were identified and followed to the end of 1988. Cumulative probability of RD repair and hospitalization for endophthalmitis was calculated by standard lifetable methods. These findings were compared with the cumulative probability of the same complications in a cohort of 330,000 patients who underwent cataract extraction on an inpatient basis in 1984. RESULTS: In the 1986-to-1987 cohort, the cumulative probability of RD within 3 years after cataract surgery was 0.81% and the cumulative probability of endophthalmitis within 1 year was 0.08%. The rate of RD is similar to that which we previously reported for 330,000 patients who underwent inpatient surgery in 1984, but the rate of endophthalmitis is significantly lower in the 1986-to-1987 outpatient cohort (0.08% versus 0.12%; z = 2.42; P = 0.01). CONCLUSIONS: The shift to outpatient cataract surgery was accompanied by no significant increase in the probability of RD repair and possibly a significant decrease in the rate of hospitalization for endophthalmitis.
Aged↗
Variation in cataract surgery practice and clinical outcomes.
PURPOSE: To examine associations between surgical technique, patient and surgeon characteristics, and clinical outcomes of cataract surgery. METHODS: Seventy-five ophthalmologists were recruited from three cities based on a sampling scheme stratified by surgeon-reported annual volume of cataract surgery. Seven hundred seventy-two patients undergoing first eye cataract surgery were enrolled, with complete preoperative, perioperative, and 4-month postoperative clinical data on 717 patients (93%). RESULTS: Sixty-five percent of surgery was performed by phacoemulsification and 35% by standard extracapsular (ECCE) techniques. Performance of ECCE was associated with the presence of ocular comorbidity and 21 or more years in practice of the surgeon. Performance of phacoemulsification was associated with annual volume of cataract surgery, wherein high-volume (201-399 patients annually) and very high-volume (> 400 patients annually) surgeons had 3.7 and 3.9 times the likelihood of performing phacoemulsification compared with moderate-volume (51-200 cases annually) surgeons. The rates of intraoperative, perioperative, and 4-month postoperative adverse events and the amount of improvement in visual acuity did not differ either by surgical technique or volume stratum. The reported occurrence of posterior capsular opacification within 4 months of surgery was increased in the presence of cortical opacification, one city, and patients operated on by either high- or very high-volume surgeons. CONCLUSIONS: In this cohort, no difference in clinical outcomes, as measured by change in visual acuity or occurrence of postoperative adverse events (except for posterior capsular opacification), can be attributed to performance of phacoemulsification versus ECCE or to the reported annual volume of cataract surgery of the surgeon. Self-reported high and very high annual volume of cataract surgery is associated independently with performance of phacoemulsification and surgeon's report of posterior capsular opacification at 4 months after cataract surgery.
Aged↗
Volatile fatty acid concentrations, enzyme activities and microflora in the rumen contents of heifers during transition to pasture.
Observations were carried out on volatile fatty acid (VFA) concentrations, enzyme activities and the microflora of the rumen contents in heifers during transition from winter to pasture feeding and in the subsequent gazing cycles. After turn-out to pasture, total VFA concentrations in the rumen contents of heifers significantly decreased from 107.7 to 88.7 mmol.l-1 (P < 0.01). After subsequent increase the total VFA concentrations reached their highest value (117.0 mmol.l-1) in the 8th week of grazing. The proportion of the molar acetic acid concentration in the rumen content increased insignificantly whereas that of propionic acid decreased insignificantly. In the molar proportion of butyric acid no significant differences could be stated. In the subsequent weeks the molar proportions of acetic acid were rather balanced and ranged within 66.2 and 68.0 mol%; the molar proportion of propionic acid insignificantly increased in the 4th week (18.7 mol%). Molar proportions of butyric acid on pasture insignificantly increased in week 3 (15.2 mol%) and appeared as balanced, later acquiring values between 14.0 and 14.8 mol%. The energetic yield of VFA production in the rumen of heifers decreased insignificantly from 73.6 to 72.15; the acetate: propionate ratio revealed an insignificant increase from 3.66 to 4.18. The enzyme activity of cellulase (endoglucanase E.C.3.2.1.4 and cellobiohydrolase E.C.3.2.1.91.) decreased significantly from 17.83 to 16.64 micrograms.ml-1 (P < 0.01); in the subsequent weeks, however, a significant increase could be observed. The enzyme activity of alpha-amylase (E.C.3.2.1.1.) decreased significantly (P < 0.05). In the 4th week a significant increase of the former occurred. The numbers of cellulolytic bacteria in the rumen content decreased significantly from 8.08 to 7.61 log 10.ml-1 (P < 0.01) and then a significant increase to 8.39 log 10.ml-1 was observed again in the 3rd week of grazing (P < 0.05). During pasture, a significant increase of the numbers of lactate-utilizing bacteria was recorded. As to the numbers of lactobacilli a significant decrease (P < 0.05) with a subsequent insignificant increase during grazing could be observed. Throughout the grazing season, the numbers of Streptococci reached values that surpassed those recorded during the winter feeding period. After transition from winter feeding to pasture the adaptation of rumen fermentation took four weeks.
Animal Feed↗
[Effect of physical treatment of rapeseed expeller, wheat, corn and corn gluten feed on the degradability in the rumen and the enzymatic in vitro digestibility of nondegraded crude proteins].
The influence of physical treatment-expansion and flaking-on crude proteins degradability in the rumen was studied in maize, maize-gluten feed, rape extracted meal and in the expanded one at 120 degrees C and 150 degrees C, rape cake, wheat and flaked wheat by in sacco method. The enzymatic digestibility of crude protein in the rumen undegraded residues of the above mentioned feeds was determined by an enzymatically in vitro method. The treatment of feed decreased significantly the original solubility and theoretical degradability of crude proteins, and the amount of undegraded crude proteins was increased. Positive influence on the amount of enzymatically digested crude protein was determined in rape expanded at 120 degrees C and 150 degrees C (60, 61 and/or 68%). Flaking of wheat had a similar effect. Enzymatic digestibility at undegraded rests where increased by 8-10% after the heat treatment and it remained almost unchanged in expanded maize-gluten feed.
Animal Feed↗
[Use of free fatty acids in animal nutrition].
The description of the processes of absorption of free fatty acids in monogastric animals and in ruminants is the first part of the review. The feeding problems of free fatty acids are discussed in the second part. In pig diets is a level up 6% free fatty acids in the dry matter of the ration not disadvantageous. In the feeding of ruminants additionally free fatty acids reduce the fermentation processes in the rumen. Only protected free fatty acids (Ca-fatty acids) are favourable in feeding systems for high yielding cows.
Absorption↗
A 210-mumol dose of vitamin A provides more prolonged impact on vitamin A status than 105 mumol among preschool children.
A randomized controlled clinical trial was conducted to determine the relative protection afforded by two large doses of vitamin A against subclinical vitamin A deficiency among 345 preschool children. At baseline, children either had or were at high risk of developing non-corneal xerophthalmia. Vitamin A status was assessed by the relative dose response (RDR) test, serum retinol concentration, and ocular examination before and 3 and 6 mo following one oral dose of 105 mumol or 210 mumol of vitamin A. At 3 and 6 mo, mean serum retinol concentration was significantly higher in the 210-mumol group than in the 105-mumol group. The proportion of children with a positive RDR did not differ between groups at 3 mo, but by 6 mo there were three times more children positive in the 105-mumol group. Most of the observed difference was confined to children with xerophthalmia at baseline. The relative benefit of the 210-mumol dose was related to baseline vitamin A status. The current World Health Organization recommended prophylactic dose of 210 mumol seems appropriate.
Child, Preschool↗
Import, targeting, and processing of a plant polyphenol oxidase.
A tomato (Lycopersicon esculentum L.) gene encoding a precursor of polyphenol oxidase (PPO) was transcribed and translated in vitro. The import, targeting, and processing of the [35S]methionine-labeled precursor protein (pPPO) were studied in isolated chloroplasts. The protein was routed to the thylakoid lumen in two steps. The 67-kD precursor was first imported into the stroma in an ATP-dependent step. It was processed to a 62-kD intermediate by a stromal peptidase. Translocation into the lumen was light dependent and involved processing of the 62-kD to the 59-kD mature form. The mature polypeptide was soluble in the lumen and not bound to thylakoids. This two-step targeting pattern was observed in plastids from a variety of plants including pea (Pisum sativum L.), tomato, and maize (Zea mays L.). The ratio between the intermediate and mature forms observed depended on the plant species, leaf age, growth conditions, and illumination regime to which the plants had been subjected. Cu2+ was not required for pPPO import or processing. Furthermore, low concentrations of Cu2+ (1-5 microM) markedly inhibited the first import step. Tentoxin specifically inhibited pPPO import, leaving the precursor bound to the envelope membrane. The two-step routing of pPPO into chloroplasts, typical of thylakoid lumen proteins, is consistent with the two-domain structure of the transit peptide and appears to be a feature of all plant PPO genes isolated so far. No evidence was found for unorthodox routing mechanisms, which have been suggested to be involved in the import of plant PPOs. The two-step routing may account for some of the multiplicity of PPO observed in vivo.
Amino Acid Sequence↗
Vitamin A: its effect on childhood sight and life.
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Child↗
Effect of vitamin A supplementation on immunoglobulin G subclass responses to tetanus toxoid in children.
Previously, we demonstrated that administering vitamin A supplements to children resulted in a significant increase in the immunoglobulin G (IgG) response generated against a vaccine dose of tetanus toxoid (TT) (R. D. Semba et al., J. Nutr. 122:101-107, 1991). However, from these analyses we could not determine whether there was an increase in levels of IgG of the subclass presumed to be important for protection against challenge by the toxin or whether there was simply a general increase in the levels of all the IgG subclasses expressing anti-TT activity. The goal of this study was to determine the profile of the anti-TT IgG subclasses in children receiving vitamin A supplementation or a placebo in order to assess the potential utility of the enhanced anti-TT response. In a randomized, double-masked, placebo-controlled clinical trial, the levels of the different anti-TT IgG subclasses were measured in 139 Indonesian preschool children (3 to 6 years of age) 2 weeks before and 3 weeks after immunization. Baseline anti-TT levels and immunization histories were used to separate those children who were responding to TT for the first time from those who responded in a secondary fashion because of previous exposure to TT. Children who were given vitamin A prior to immunization had significant increases in IgG1 levels regardless of whether they were undergoing primary or memory reactions. In the group of individuals who underwent a secondary response to TT, vitamin A supplementation was also associated with a modest but significant change in the levels of anti-TT IgG3. There were only minor changes in the levels of anti-TT IgG2 and IgG4. Since IgG1 is the subclass associated with a protective response to TT immunization, these results suggest that vitamin A supplementation may be a safe and effective intervention to enhance the relevant humoral response to TT and other vaccine antigens.
Adjuvants, Immunologic↗
Familial adrenal insufficiency, achalasia, alacrima, peripheral neuropathy, microcephaly, normal plasma very long chain fatty acids, and normal muscle mitochondrial respiratory chain enzymes.
Adrenal insufficiency has been associated with adrenoleukodystrophy and adrenomyeloneuropathy. In these diseases, plasma very long chain fatty acids are elevated. Peripheral neuropathy is frequently seen in adults with adrenomyeloneuropathy. We encountered two first cousins with adrenal insufficiency, who also developed peripheral neuropathy, achalasia, alacrima, and microcephaly. However, plasma very long chain fatty acids, pipecolic acid, phytanic acid, and cranial computed tomographic scan were normal. Muscle mitochondrial respiratory chain enzymes were also normal. This syndrome of adrenal insufficiency, achalasia, alacrima, microcephaly, and peripheral neuropathy is different from either adrenomyeloneuropathy or adrenoleukodystrophy.
Adolescent↗
Primary cultures of rat islet capillary endothelial cells. Constitutive and cytokine-inducible macrophagelike nitric oxide synthases are expressed and activities regulated by glucose concentration.
We have succeeded in obtaining cultures of pure rat islet capillary endothelial cells. These multiply in vitro and exhibit the same antigenic phenotype as expressed in situ: von Willebrand factorhigh, Ox43 (rat endothelial marker)weak, and Ox2 (thymocyte and brain endothelium marker)high. This phenotype differs from both exocrine endothelium stained in situ and rat aorta endothelial cells cultured in vitro under identical conditions. Islet and aorta endothelial cells were cultured in the presence of various glucose concentrations. Nitrite and citrulline concentrations in culture supernatants were measured as an indirect quantification of nitric oxide formation. In islet endothelia, both nitrite and citrulline levels were found to be strongly glucose-dependent, with high levels at high glucose concentrations and vice versa, in contrast to aorta endothelial cells, where no glucose effect was found. Shifting islet endothelial cultures from high to low glucose levels or the reverse led to a slow decrease or increase in nitrite and citrulline formation with several cell generations needed to reach steady levels. Adding a combination of the cytokines interleukin-1 beta, tumor necrosis factor-alpha, and interferon-gamma to both endothelial cell cultures led to a dramatic increase of nitric oxide formation. Again with islet but not with aorta endothelial cells a modulating effect by glucose concentrations was found. Reverse-transcription-polymerase chain reaction with specific primers demonstrated the presence of constitutively expressed nitric oxide synthase-RNA in the islet capillary endothelial cells and confirmed the glucose effect. In addition, we found that cytokines indeed induce the expression of inducible synthase messenger RNA in both endothelial cells, which was not found in the absence of cytokines. Electron paramagnetic resonance spectroscopy of islet endothelial cells confirmed intracellular synthesis of nitric oxide in the presence of cytokines. In conclusion, we here for the first time provide evidence that constitutive nitric oxide synthase is also expressed in capillary endothelium and that cytokine challenge leads to the expression of the inducible isoform in these cells.
Amino Acid Oxidoreductases↗