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Biomedical subjects

J Lindberg

Publications and source records attributed to J Lindberg.

At least 55 records · Page 3Linked to original sources
PubMed1994

Calcium oxalate stone agglomeration reflects stone-forming activity: citrate inhibition depends on macromolecules larger than 30 kilodalton.

To evaluate the clinical utility of in vitro calcium oxalate monohydrate (COM) crystallization kinetics measurements and to determine the effect of quantitative removal of urinary Tamm-Horsfall glycoprotein on such measurements, we examined 24-hour, room temperature urine collections of patients from our Stone Clinic and of normal subjects from our research laboratories at Ochsner Medical Institutions in New Orleans, LA, and compared their COM kinetic parameters in vitro before and after urine ultrafiltration (30 kd). Data from 53 calcium oxalate stone-forming patients (26% women; mean age, 47 years) who demonstrated radiographic or other evidence of forming at least one stone were compared with data from 22 healthy volunteers (25% women; mean age, 40 years). Hypercalciuria (> 7.5 mm/24 hr), hyperoxaluria (> 0.5 mm/24 hr), and hypocitraturia (< 2.0 mm/24 hr) were present in 38%, 26%, and 26% of the patient population, respectively. Urinary creatinine, urate, calcium, citrate, phosphate, oxalate, pH, volume, total immunoreactive-disaggregated Tamm-Horsfall glycoprotein, and the urine's effects on COM solubility, percent crystal growth inhibition, and crystal agglomeration inhibition [tm] were determined. Calcium oxalate monohydrate agglomeration inhibition, [tm], was reduced in stone-forming patients. It decreased with increasing stone frequency, making [tm] a useful tool for measuring the risk of stone recurrence. Urinary Tamm-Horsfall glycoprotein and citrate concentrations were linearly related to COM agglomeration inhibition. Their effects were synergistic. Tamm-Horsfall glycoprotein removal from urine reduced COM agglomeration inhibition dramatically. Alkali therapy increased urinary citrate concentration and increased [tm].(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Septic arthritis of the knee: a 10-year review and long-term follow-up using a new scoring system.

The case records of 64 patients with 65 episodes of infectious gonarthritis during 1979-88 were reviewed regarding epidemiological, clinical and laboratory data of possible relevance to the course and outcome of the disease. Long-term healing results were evaluated by means of a new scoring system 2-11 years after the acute disease in 46 patients. The infection was acquired by inoculation in 37% and by the hematogenous route in 55%. The major risk factors were trauma to the joint and arthrosis. Staphylococcus aureus was the causative agent in 58% and Streptococci in 15%. Treatment consisted of suction irrigation (86%) or intermittent aspiration (5%) combined with systemic antibiotic treatment. At follow-up, the pain and ache scores of the arthritic joint had decreased by 21% and 16% respectively, compared with the scores of the contralateral control joints. Anatomy and motility were reduced by 9% and 8% respectively. Age < 45 was associated with a greater score loss than in older patients. Treatment delayed by > 5 days was associated with increased loss of motility. We estimate that 79% of the patients had excellent or good long-term results following treatment of infectious arthritis of the knee. Evaluation of healing after infectious gonarthritis by use of a scoring system is quite feasible and allows comparison of different treatment regimes with improved accuracy.

Adolescent↗
PubMed1994

Assessing the relationship between a multidimensional psychological "control profile" and cardiovascular risk.

This article begins by citing apparently conflicting sets of literature regarding the association between control and cardiovascular risk. Each set of findings is based on a unidimensional understanding of control. To gain more precise information, a multidimensional control inventory, the Shapiro Control Inventory (SCI), was given to twenty individuals at the time of their yearly physical. Results showed that low perceived control on the domain specific control scale was associated with higher cardiovascular risk. Further, several findings between specific risk parameters--smoking, calories from fat, blood pressure, and cholesterol level (HDL)--were significantly associated with different dimensions of the control profile. Case study data from the two individuals at highest risk suggest that different control profiles may be associated with cardiovascular risk. Guidelines and suggestions for future research are offered.

Adult↗
PubMed1993

Structural studies of acetan, an exopolysaccharide elaborated by Acetobacter xylinum.

The exopolysaccharide acetan, elaborated by Acetobacter xylinum, has been investigated. The polysaccharide and a heptasaccharide, obtained on enzymic hydrolysis, corresponding to the repeating unit were characterised by sugar and methylation analysis and by NMR spectroscopy and MS. It is concluded that the polysaccharide is composed of repeating units with the following structure. [formula: see text] The polysaccharide further contains approximately two O-acetyl groups per repeating unit, which have not been assigned, but it appears that they are on primary locations.

Carbohydrate Conformation↗
PubMed1993

Doxycycline and pyrimethamine for toxoplasmic encephalitis.

Clinical improvement is reported in a 40-year-old man with AIDS and presumed toxoplasmic encephalitis, who was treated with doxycycline, 400 mg, and pyrimethamine, 25 mg, daily. Computerised tomography (CT) scanning of the brain showed complete resolution of 2 ring-enhanced lesions within 5 weeks.

AIDS-Related Opportunistic Infections↗
PubMed1993

Comparison of hypertonic saline solutions and dextran in dialysis-induced hypotension.

The efficacy of three hypertonic saline solutions for treating dialysis-induced hypotension in a randomized, blinded, crossover clinical trial of 10 patients (a minimum of three cycles per solution) was compared. Dialysis-induced hypotension, defined as a decrease in systolic blood pressure of at least 10 mm Hg or systolic blood pressure less than 100 mm Hg, was treated with an iv bolus of either 10 mL of 23% saturated hypertonic saline, 30 mL of 7.5% hypertonic saline, or 30 mL of 7.5% saline with 6% dextran 70, each containing similar osmolar loads of 80, 80, and 100 mosM, respectively. All three solutions raised systolic blood pressure within 5 min (mean pretreatment systolic blood pressure, 87 mm Hg; mean posttreatment systolic blood pressure, 101 mm Hg; P < 0.05). The magnitude of the increase was greater with saturated hypertonic saline (15 mm Hg) and dextran 70 (17 mm Hg) compared with that with hypertonic saline (9 mm Hg; P < 0.05). At 10 min, dialysis-induced hypotension was less frequent with saturated hypertonic saline (incidence, 9%) compared with hypertonic saline (45%). Beyond 10 min, however, there was a trend toward a lower incidence of further dialysis-induced hypotension with dextran 70. There were no side effects. Given equal osmole loads, the more concentrated solution produced a greater increase in systolic blood pressure. The addition of an oncotic agent such as dextran may prolong the blood pressure response beyond 10 min. It was concluded that hypertonic saline solutions safely and effectively treat dialysis-induced hypotension.

Aged↗
PubMed1992

Distribution of substituents in O-(2-hydroxypropyl) derivatives of cyclomalto-oligosaccharides (cyclodextrins: influence of increasing substitution of the base used in the preparation, and of macrocyclic size.

Samples of O-(2-hydroxypropyl)derivatives of cyclomaltoheptaose (beta-cyclodextrin) with increasing substitution were prepared by withdrawing aliquots at different times from a reaction mixture containing cyclomaltoheptaose and an excess of (S)-propylene oxide in 0.39 M aqueous sodium hydroxide. The distributions of substituents between the different molecules and between the different alpha-D-glucopyranosyl residues in these samples were determined by mass spectrometry and methylation analysis, respectively. The solubilities of the samples and their association constants with phenolphthalein were also determined. The relative reactivities at O-2 and O-3 versus O-6, calculated using Spurlin's equations, decreased with increasing degree of substitution, probably because of steric hindrance. No significant differences were observed when different strong bases were used as promoters of the hydroxypropylation of cyclomaltoheptaose. The hydroxypropylation of cyclomaltohexaose (alpha-cyclodextrin) and cyclomalto-octaose (gamma-cyclodextrin) was briefly investigated.

Carbohydrate Conformation↗
PubMed1992

Evaluation of impact loading in overhead work using a bolt pistol support.

This paper evaluates the effects of a bolt gun support stand on impact loading of the hand-arm system while firing spiked bolts into a steel beam. Ten healthy male subjects fired two bolts into the centre of the beam, one with and one without the aid of the support stand. During firing of a bolt gun, the shock sequences were recorded by two accelerometers. The analysis showed that peak values of acceleration decreased more than eightfold during firing with the bolt pistol support. The shock damping effect due to the bolt support was noted at the thumb (metacarpal level) and elbow bones.

Accidents, Occupational↗
PubMed1992

Chronic liver disease in Ethiopia: a clinical study with emphasis on identifying common causes.

Between July 1986 and April 1989, 334 hospitalized adult Ethiopian patients with chronic liver disease were studied according to a protocol to define their clinical features and to identify risk factors with the aim of preventive intervention. Of these, 14 had chronic hepatitis, 208 cirrhosis and 112 hepatocellular carcinoma (HCC). Both clinical and histological diagnostic criteria were employed. A detailed questionnaire was used to document demographic and clinical data. A common clinical presentation among patients with chronic hepatitis was darkening of the face and hands with or without hypertrichosis of the face and blisters over the dorsi of the hands. This overt or latent form of porphyrea cutanea tarda (PCT) responds to chloroquine. Patients with cirrhosis of the liver commonly present for the first time with ascites, splenomegaly, haematemesis and/or melena from oesophageal varices, and mental changes due to hepatic encephalopathy. Overt or latent forms of PCT are also common features. Peculiar to these cirrhotics is the rarity of spider naevi, gynaecomastia, testicular atrophy, Dupuytren's contracture, parotid gland enlargement and clubbing of the fingers. Exhaustion, loss of appetite, rapid loss of weight, right upper quadrant and/or epigastric pain (all often of less than 6 months' duration, a big, hard, tender and grossly nodular liver with bruit, signs of portal hypertension, and/or hepatic encephalopathy, in a young male with a rapid down hill course characterize the Ethiopian patient with HCC. Serum anti-nuclear factor, anti-mitochondrial anti-bodies and anti-smooth muscle anti-bodies were absent in those with chronic hepatitis and were uncommon in the cirrhotics and HCC cases. One or more hepatitis B virus markers were found in 86% of chronic hepatitis, 88% cirrhosis and 78% HCC and the HBsAg carrier state was found in 36%, 29% and 23%, respectively. Among the HBsAg carriers, HBeAg positivity was less common than anti-HBe but anti-HDV was significantly higher than in the healthy general population. Alphafetoprotein (AFP) levels greater than 500 mg/ml were present in 16 (8%) cirrhotics and 58 (52%) patients with HCC. Histologically, 3 of the chronic hepatitis patients had progressed to cirrhosis, 8 of the cirrhotic patients had chronic active hepatitis and 85% of HCC cases occurred in a background of macronodular cirrhosis. Three cirrhotics developed HCC during follow-up.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

Synthesis of some 2-O-(2-hydroxyalkyl) and 2-O-(2,3-dihydroxyalkyl) derivatives of cyclomaltoheptaose.

On alkylation of cyclomaltoheptaose with oxiranes, promoted by alkali of low concentration, substitution at secondary positions, particularly at O-2, is favoured. The reaction has been used to prepare the 2-O-[(R)- and (S)-2-hydroxypropyl], 2-O-(2-hydroxy-2-methylpropyl), 2-O-[(R)- and (S)-2,3-dihydroxypropyl], and 2-O-[(R)- and (S)-2,3-dihydroxy-2-methylpropyl] derivatives. Each of these derivatives is less soluble in water than cyclomaltoheptaose, and their complexes with toluene, in contrast to that of cyclomaltoheptaose, are well soluble in water.

Carbohydrate Conformation↗
PubMed1991

The structure of the capsular polysaccharide from Streptococcus pneumoniae type 7B.

The capsular polysaccharide elaborated by Streptococcus pneumoniae type 7B is composed of the following heptasaccharide repeating-units. [formula: see text] The identities and modes of linkage of the constituents were established using sugar, methylation, and phosphorus analysis, together with 1D- and 2D-n.m.r. spectroscopy. The sequence was established from inter-residue n.O.e. data. The structure was corroborated by n.m.r. spectroscopy, f.a.b.-m.s., and methylation analysis of the oligosaccharides isolated after partial acid hydrolysis of the polysaccharide with aqueous 48% hydrogen fluoride. It is suggested that the structural basis for the common antigenic formula in the group 7 serotypes of S. pneumoniae is the disaccharide element alpha-D-GlcpNAc-(1----2)-alpha-L-Rhap-(1----.

Carbohydrate Conformation↗
PubMed1991

Structural studies of the Vibrio cholerae O:3 O-antigen polysaccharide.

The structure of the Vibrio cholerae O:3 O-antigen polysaccharide has been investigated, mainly by n.m.r. spectroscopy, mass spectrometry, sugar and methylation analysis, and specific degradations, and is proposed to involve the following tetrasaccharide repeating-unit. [formula: see text]. In this structure, D-D-Hep is D-glycero-D-manno-heptose, Asc is 3,6-dideoxy-L-arabino-hexose (ascarylose), and Sug is 2,4-diamino-2,4,6-trideoxy-D-glucose (bacillosamine) in which N-2 is acetylated and N-4 is acylated with a 3,5-dihydroxyhexanoic acid. That the 2,4-diamino-2,4,6-trideoxy-D-glucose residue is linked through O-3 and not through one of the hydroxyl groups in the 3,5-dihydroxyhexanoyl group is indicated but not definitely proved. The configuration of the latter group has not been determined. The f.a.b.-mass spectrum of the methylated O-antigen indicates that the structure given above also represents the biological repeating-unit.

Carbohydrate Conformation↗
PubMed1990

Immunogenicity of hepatitis B vaccine simultaneously administered with the expanded programme on immunisation (EPI).

To assess the immunogenicity of hepatitis B vaccine simultaneously administered with the Expanded Programme on Immunisation (EPI) vaccines, a total of 300 consecutive infants, ranging in age between 6 weeks and 6 months, were alternatively assigned to the revised EPI and to EPI plus plasma-derived hepatitis B vaccine (Hevac B Pasteur). Four dosages (2 mcg or 0.5 ml each) of hepatitis B vaccine were given intramuscularly. HBsAg, anti-HBc, and anti-HBs were determined at day 0 and at day 210 in both groups by radioimmunoassay methods. The anti-HBs titre levels and geometric mean titres (GMTs) were determined at day 180 and day 210. There were three new hepatitis B virus infections in the control group and none in the study group by day 210. The seroconversion rates in the study group were 66% at day 180 and 84% at day 210, the respective GMTs being 116 and 940. Although the duration of observation is short (7 months) and the difference in the rate of infection between the two groups is not statistically significant (P greater than 0.05), the immunogenicity of the vaccine appears to be good. The simultaneous administration of hepatitis B vaccine and the EPI vaccines is logistically ideal. However, we suggest a further study using a larger dose of the Hevac B Pasteur vaccine to find out if a higher seroconversion rate than the 84% observed in this study could be achieved.

Female↗
PubMed1990

Effect of magnesium citrate and magnesium oxide on the crystallization of calcium salts in urine: changes produced by food-magnesium interaction.

The effect of magnesium citrate and magnesium oxide on urinary biochemistry and on the crystallization of calcium salts was examined in 7 normal subjects and 4 patients with recurrent calcium oxalate nephrolithiasis. When magnesium citrate or magnesium oxide was administered on an empty stomach (10 mEq. 4 times per day or 486 mg. magnesium per day for 2 weeks) urinary magnesium increased by only 77 to 79 mg. per day and urinary citrate increased by 98 to 142 mg. per day. However, urinary calcium increased by 21 to 25 mg. per day. No significant changes were noted in urinary saturation of calcium oxalate or brushite or in the limit of metastability (formation product) of these salts. However, when magnesium salts were provided with meals there were more prominent increases in urinary magnesium (by 92 to 96 mg. per day) and in citrate (by 218 to 226 mg. per day). Moreover, urinary oxalate decreased. Owing to these changes the urinary saturation of calcium oxalate decreased and the formation product increased. If magnesium citrate and magnesium oxide are to be used in the management of recurrent calcium oxalate nephrolithiasis, they should be administered with meals.

Adult↗