Higher Weight Increase Research Articles

Development and Characterization of a Hydrogel Containing Silver Sulfadiazine for Antimicrobial Topical Applications

Development and optimization of a hydrogel with impregnated silver sulfadiazine was pursued, for antimicrobial topical applications. The selected hydrogel exhibited a homogeneous appearance, with whitish colloration and devoid of any fractures or cracks. The content in impregnated silver sulfadiazine was within established limits (1%, w/w) with a standard deviation of up to 1.28%. The hydrogel presented a good characteristic in relation to release of the active antimicrobial principle, verified through swelling tests and antimicrobial activity. The swelling tests indicated a higher increase in weight during the first 6 h of contact with a moist environment, with a maximum value of 266.00 ± 0.81, and with maintenance of the original shape of the hydrogel. The impregnated silver sulfadiazine presented antimicrobial activity, as expected, indicating a prolonged release of the drug. The infrared spectra of the hydrogel with impregnated silver sulfadiazine indicated that the drug did not engage in any bonds with the polymeric matrix, which otherwise could have reduced its antimicrobial activity. The mechanical resistance tests produced good results, indicating that the hydrogels may be utilized in different locations of the human body with skin lesions.

Comparative effect of local and foreign commercial feeds on the growth and survival of Clarias gariepinus juveniles

Growth and survival of Clarias gariepinus juveniles fed with a local feed and coppens commercial feed were observed for 16 weeks at the laboratory of the Department of Zoology, University of Ilorin, Nigeria. The proximate compositions and economics of the feeds and water quality of the cultured tanks were assessed. Fish fed with coppens showed significant (P<0.05) higher weight increase, specific growth rate, protein efficiency ratio and low food conversion ratio than fish fed with local feed. Significant (P<0.05) higher mortality were recorded in fish fed with the local feed. The growth performance was a reflection of the proximate composition of the feeds with local feed having low crude protein (10.95%), lipid (3.95%) and ash (4.92%) when compared to coppens which had 42% crude protein, 12% lipid and 9.5% ash with protein being most significant. Carbohydrate (69.90%) and crude fiber (2.88%) were higher in the local feed than in coppens with an imbalance in carbohydrate and lipid ratio. Mortality was attributed to stress resulting from the poor quality of the feed. Cost of feeding with local feed to a weight gain of 31.67g was ₦80, while the cost of feeding with coppens to a weight gain of 148.58g was ₦16.

Comparative effect of local and foreign commercial feeds on the growth and survival of Clarias gariepinus juveniles

Growth and survival of Clarias gariepinus juveniles fed with a local feed and coppens commercial feed were observed for 16 weeks at the laboratory of the Department of Zoology, University of Ilorin, Nigeria. The proximate compositions and economics of the feeds and the water quality of the cultured tanks were assessed. Fish fed with coppens showed significant (P<0.05) higher weight increase, specific growth rate, protein efficiency ratio and low food conversion ratio than fish fed with local feed. Significant (P<0.05) higher mortality were recorded in fish fed with the local feed. The growth performance was a reflection of the proximate composition of the feeds with local feed having low crude protein (10.95%), lipid (3.95%) and ash (4.92%) when compared to coppens which had 42% crude protein, 12% lipid and 9.5% ash with protein being most significant. Carbohydrate (69.90%) and crude fiber (2.88%) were higher in the local feed than in coppens with an imbalance in carbohydrate and lipid ratio. Mortality was attributed to stress resulting from the poor quality of the feed. Cost of feeding with local feed to a weight gain of 31.67g was ₦80, while the cost of feeding with coppens to a weight gain of 148.58g was ₦16.

Materials Characterization Approaches for Optimization of Microbial Fuel Cell Electrodes

Materials Characterization Approaches for Optimization of Microbial Fuel Cell Electrodes

Application of fish gelatin as diet binder in diets for the common carp Cyprinus carpio L. fingerlings

Fish gelatin applied as an animal source binder and stabilizer in diets for the common carp Cyprinus carpio L. fingerlings in comparison with binder void diet. Experimental diets prepared from standard raw materials adding laboratory made fish gelatin at 1% as binder. Three types of gelatin applied (extracted from tilapia Tilapia zilli skins, common carp Cyprinus carpio L. gas bladder and barred needlefish Ablennes hians heads). Three diets containing each type of extracted gelatin were prepared to compare with gelatin void diet. Fish initial average weight 5.56 gm were fed at 5% body weight daily. Chemical and physical analyses performed on pellets thrown into water to feed fish as affected by added gelatin. The influences of gelatin monitored on pellet density, floating period, sinking velocity, water absorption rate and disintegrating rate as indicators for pellet quality and resistance into water. Feed intake by fish during research period studied also. Results showed that bladder gelatin diet gave the highest weight increase in comparison with other diets which reached 15.6gm. Physical measurements demonstrated that the highest density recorded in bladder gelatin diet (1.4 gm/cm 3 ) followed by head and skin gelatin diets (1.3 gm/cm 3 ) while the lowest density recorded in gelatin void diet (1.1 gm/cm 3 ). Floating time of 8.55 sec. and sinking velocity of 1.06 sec./cm recorded for bladder gelatin diet in comparison with 7.53, 7.31 and 5.30 sec. for floating time and 1.37, 1.43 and 2.47 sec./cm for sinking velocity of diets containing head , skin gelatin and control, respectively. Various treatment indicated impacts on growth where weight increase rated 10.26-15.6 g, specific growth rate 1.10-1.61 and relative growth rate 39.46-62.40 %. Bladder gelatin diet surpassed others in weight increase, specific and relative growth rates. Feed conversion ratios reached 3.156, 2.862, 3.597 and 4.306 for skin, bladder, head gelatin and control diets, respectively. As for feed intake, bladder gelatin treatment gave the highest values. Chemical composition did not affected by using binders.

Biochemical signs of impaired cobalamin function do not affect hematological parameters in young infants: results from a double-blind randomized controlled trial

Whereas iron deficiency is considered the leading cause of anemia in infants, cobalamin deficiency is foremost characterized by developmental delay, and the typical macrocytic anemia is confined to severe and longstanding cobalamin deficiency in this age group. Hematological parameters were investigated in 4-mo-old infants with biochemical signs of impaired cobalamin function who participated in a randomized controlled cobalamin intervention study at 6 wk. One hundred and seven infants were randomly assigned to receive either an intramuscular injection with 400 μg cobalamin or no intervention at 6 wk. Hematological parameters, and cobalamin and folate status were determined at inclusion and 4 mo. Cobalamin supplementation improved all markers of impaired cobalamin function but had no effect on hematological cell counts at 4 mo (P > 0.18). Signs indicative of an iron-restricted erythropoiesis were observed at 6 wk and 4 mo. At 4 mo, the strongest predictors of low iron status were male gender and a high percentage weight increase from birth. In infants with biochemical signs of impaired cobalamin function, supplementation does not improve hematological cell counts. Variations in erythrocyte parameters seem to be foremost associated with iron status in this age group.

Growth of pike larvae: effects of prey, turbidity and food quality

We studied experimentally the effects of turbidity and prey composition on pike larval growth and hypothesized that pike larval growth varies with turbidity and food quality. We reared the first-feeding pike larvae (Esox lucius) in laboratory tanks with (1) clear or (2) turbid water provided with zooplankton rations from (3) an inner and (4) an outer archipelago site. The sites differ in physical features, salinity, eutrophication status, zooplankton community structure and density. Pike larvae showed the highest weight increase in clear water with zooplankton from the outer site and the poorest weight increase in turbid water with zooplankton as prey from the inner site. Our fatty acid analysis revealed that unsaturated fatty acid levels were highest in the outer site. The relative percentage of copepods was also higher in the outer site. This study supports the hypothesis that turbidity weakens the ability of pike larvae to capture certain prey. Further, zooplankton community composition matters in turbid water, but is not a primary factor in clear water.

Morphology and mechanical properties of poly(ethyleneoctene) copolymers obtained by dynamic packing injection molding

The morphology and mechanical properties of poly(ethylene-octene) copolymers (POE) obtained by dynamic packing injection molding were investigated by mechanical tests, differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The mechanical tests found that only POE with low octene content and high molecular weight show apparent response for external shear field. Further investigation has been done by DSC, FT-IR, and SEM in order to make clear the reason of that phenomenon. Finally, the hypothetical mechanism of POE microstructure formation under shear field has been proposed. For POE with low octene content and high molecular weight, orientation degree and mechanical properties both increase substantially under shear field. For POE with low octene content and low molecular weight, orientation degree and crystallinity increase under shear field, but it is not dramatically benefit for the mechanical properties. For POE with high octene content and high molecular weight, the shear field has little effect on the morphology and mechanical properties.

Effects of Long Chain Cellulose Ester on Mechanical Properties of Polylactic Acid Reinforced with Microcrystalline Cellulose

Long chain cellulose ester (LCCE) synthesized by acylation reaction via microwave process was used as a compatibilizer for banana stem microcrystalline cellulose/polylactic acid (BS MCC/PLA) composite. The proper reaction time and power output for LCCE synthesis were 150 second and 160 watt, respectively, which resulted in the highest weight increase (%) of LCCE synthesis. The FT-IR and NMR results confirmed that long chain acyl ester was grafted on cellulose structure. The degree of substitution (DS) of LCCE was 2.41. The BS MCC content was fixed at 40wt% while LCCE content was varied from 0-9 wt%. The Tensile properties properties of BS MCC/PLA composites with or without LCCE were studied by tensile test. The results revealed that the addition of LCCE enhanced the elongation at break of 40wt% BS MCC/PLA composite owing to the improvement of compatibility between PLA and MCC, particularly the addition of 5wt% of LCCE which led to the highest elongation at break. However, when the addition of LCCE was greater than 5wt%, the elongation at break was slightly decreased because of the small aggregation of BS MCC and LCCE in PLA matrix as supported by morphological analysis. Nevertheless, the addition of LCCE contributed to the decrease in tensile strength and Young’s modulus of 40wt% BS MCC/PLA composite slightly because of the decreasing of crystallinity in PLA composite.

Nutrient Enrichment of Mother's Milk and Growth of Very Preterm Infants After Hospital Discharge

To determine if the addition of a multinutrient human milk fortifier to mother's milk while breastfeeding very preterm infants after hospital discharge is possible and whether it influences first-year growth. Of a cohort of 320 infants (gestational age: 24-32 weeks; birth weight: 535-2255 g), breastfed infants (65% [n = 207]) were randomly assigned shortly before hospital discharge to receive either unfortified (n = 102, group A) or fortified (n = 105, group B) mother's milk until 4 months' corrected age (CA). The remaining infants were bottle-fed with a preterm formula (group C). Follow-up was performed at term and at 2, 4, 6, and 12 months' CA. Mean duration of breastfeeding after term was not significantly different between groups A and B (11.8 and 10.6 weeks, respectively). Weight, length, and head circumference were not significantly different between groups A and B at 12 months' CA. Compared with groups A and B, infants in group C had a higher increase in weight z score until term and in length z score until 6 months' CA. At 12 months' CA, boys in group C were significantly longer and heavier compared with those in groups A and B, whereas girls in group C were longer and heavier compared with those in group A only. A higher protein intake was related to a higher serum urea nitrogen level and growth. Fortification of mother's milk after hospital discharge while breastfeeding very preterm infants was possible without influencing breastfeeding duration but did not significantly influence growth parameters at 1 year of age compared with unfortified mother's milk.

Water Uptake Threshold of Rabbiteye (Vaccinium ashei) Blueberries and Its Influence on Fruit Splitting

Split-resistant and split-susceptible rabbiteye blueberry fruit were evaluated at all stages of development to determine “water uptake thresholds” by soaking in distilled water. Weight increase after soaking was measured, and percent weight gain was calculated to take into consideration the weight increase of the fruit from development. The ratio of percent increase in volume to weight increase resulting from water uptake was calculated. Ratios of percent water uptake to weight increase between split-susceptible ‘Tifblue’ and split-resistant ‘Premier’ blueberries were found to be similar. The split-susceptible ‘Tifblue’ had a 1.6 g/50 fruit increase with a 1.7% water uptake and a ratio of 1.08. ‘Premier’ had a higher weight increase with 3.3 g/50 fruit and also a higher percentage of water uptake at 3.6% providing a ratio of 1.09. Although both absorbed water at a constant rate shown by a linear increase of weight increase over time, ‘Premier’ absorbed a significantly greater amount of water than did ‘Tifblue’ yet remained intact and did not split.

Lower weight gain with the orally disintegrating olanzapine than with standard tablets in first‐episode never treated psychotic patients

A post-hoc analysis of the data from a randomised clinical trial involving prescription of antipsychotic treatment to never treated first-onset psychotic patients was used to compare the weight change after 6-week olanzapine treatment (standard tablets vs. orally disintegrating formulation). In the subgroup of 38 patients randomised to olanzapine, standard olanzapine tablets were non-randomly and consecutively prescribed to the first 19 patients, with the orally disintegrating formulation being prescribed to the following 19 patients. After 6-week treatment with olanzapine, a significant higher increase in weight was noted in those patients on standard tablets (mean weight increase 6.3 +/- 1.9 Kg) as compared to those on orally disintegrating olanzapine (mean weight increase 3.3 +/- 3.2 Kg) (F = 7.7; p = 0.009). BMI increase was also significantly higher in the olanzapine tablet group (mean increase of 2.1 Kg/m(2) as compared with 1.1 Kg/m(2) in the orally disintegrating group) (F = 4.7; p = 0.036). Substantial weight gain (SWG) (> or =7% increase from baseline weight) was noted in 84.2% (n = 16) of the olanzapine tablet patients and in 31.6% (n = 6) of the orally disintegrating olanzapine patients, with the olanzapine tablet group showing a significant increase in the mean percentage of weight gain (F = 4.0; p = 0.014). Partial sublingual absorption occurring with orally disintegrating olanzapine may bypass gastrointestinal metabolisation and hence lead to differences in metabolite versus parent compound ratios. However, the need arises to replicate the present study with a longer follow-up.

Maslinic acid as a feed additive to stimulate growth and hepatic protein-turnover rates in rainbow trout ( Onchorhynchus mykiss)

Maslinic acid is a triterpene present in a considerable proportion in solid residues from olive-oil production. In the present work the effects of maslinic acid on growth, protein-turnover rates and nucleic-acid concentration on liver were investigated in the rainbow trout. Five groups of 120 fish of a mean body mass of 20 g were fed for 225 days with diets containing 0, 1, 5, 25 and 250 mg of maslinic acid per kg diet. At the end of the experiment, whole-body and liver weight and growth rate of trout fed with maslinic acid were higher than controls. The highest weight increase was registered for the group fed 250 mg kg − 1 , representing a 29% increase over controls. The total hepatic DNA or liver cell hyperplasia levels in trout fed with 25 and 250 mg of maslinic acid kg − 1 were 37% and 68% higher than controls. Also in these same groups of trout, fractional and absolute hepatic protein-synthesis rates were significantly higher than in control, and significant increments in hepatic protein-synthesis efficiency and protein-synthesis capacity were reported. In close agreement with these results, microscopy studies showed that trout fed on 25 and 250 mg kg − 1 hepatocytes appeared to be more compact, with a larger rough-endoplasmic reticulum and larger glycogen stores than controls. These results suggest that maslinic acid can act as a growth factor when added to trout diet.

Effect of steam on bonding strength and dimensional stability of laminated veneer lumbers manufactured using different adhesives

Laminated veneer lumbers (LVLs) manufactured from wood with different adhesives are being increasingly used in the construction of furniture frames and buildings. Yet there is little information available concerning the dimensional stability and shear strength of LVLs after being exposed to steam. In this study, LVLs were manufactured from poplar and beech veneers with phenol/formaldehyde (PF), poly(vinyl acetate) (PVAc), Desmodur-VTKA (D-VTKA) and urea/formaldehyde (UF) adhesives. Dimensional stability of LVLs was measured after being exposed to steam for 2, 6, 12, 24, 48 and 96 h, according to the Turkish Standard (TS) 3639, and also shear strength was measured (according to BS EN 205). The highest initial density of 0.93 g/cm3 was for beech LVL with VTKA adhesive. After exposure to steam for 96 h, the highest weight increase of 65.7% was for poplar LVL with PVAc, the highest radial swelling of 5.7% was for beech LVL with UF, the highest tangential swelling of 7.9% was for beech LVL with PF and the highest longitudinal swelling of 0.5% was for beech LVL with VTKA. The highest shear strength value of 15.8 N/mm2 among all samples without exposure to steam was obtained for beech LVL with PVAc adhesive and the lowest shear strength was obtained as 4.48 N/mm2 for poplar LVL with UF adhesive.

Bone and Body Composition of Children and Adolescents With Repeated Forearm Fractures

DXA measurements in 90 children and adolescents with repeated forearm fractures showed reduced ultradistal radius BMC and BMD values and elevated adiposity, suggesting site-specific bone weakness and high body weight increase fracture risk. Symptoms to cow milk, low calcium intakes, early age of first fracture, and overweight were over-represented in the sample. Although many apparently healthy children fracture their forearms repeatedly during growth, no previous studies of their bone health and body composition have been undertaken. Nor has the prevalence of established risk factors for fracture in such a population been assessed. Ninety children and adolescents (47 girls and 43 boys) 5-19 years of age, who had experienced at least two fractures of the forearm, were studied. Bone size and mineralization were assessed using DXA at the ultradistal radius, one-third radius, neck of femur, hip trochanter, lumbar spine, and total body. Total body lean mass and fat mass were also determined. The prevalence of six risk factors for fracture were also examined, and their influence on ultradistal BMC Z scores was assessed. Participants experienced 295 fractures (74.9% forearm). Children with an early age of first fracture had higher rates of fracture per l00 years of exposure than those fracturing later. Four risk factors for fracture were over-represented in observed versus expected percentages: early age of first fracture (27.7% versus 11.3%), adverse symptoms to cow milk (22.2% versus 6.7%), low dietary calcium intake (20% versus 4.5%), and overweight (33.3% versus 15.5%). However, physical activity levels were similar to the reference population. Z scores for BMC and BMD were reduced, particularly at the ultradistal radius, whereas Z scores for weight, body mass index, fat mass, and body fat percentage were increased. Mean (SD) BMC Z scores were lowest at the ultradistal radius, -0.66 (1.22), where symptoms to milk were associated with reduced values (p < 0.009) and overweight with increased values (p < 0.003). Our results suggest site-specific weakness and high body weight contribute to fracture risk in children and adolescents who fracture their forearms repeatedly. These findings are consonant with work showing adult Colles fractures increase as ultradistal radius BMD falls and with evidence that overweight children and adolescents are fracture prone.

Olanzapine vs. other antipsychotics in actual out‐patient settings: six months tolerability results from the European Schizophrenia Out‐patient Health Outcomes study

The European Schizophrenia Out-patient Health Outcomes study is an observational study investigating treatment in schizophrenia. We report treatment-emergent adverse events during the first 6 months of treatment. The rate of extrapyramidal symptoms (EPS), anticholinergic use, weight gain and sexual related dysfunctions were assessed in 8,400 out-patients. Patients typical antipsychotics and risperidone experienced significantly more EPS and anticholinergic use than patients in the clozapine, olanzapine, and quetiapine cohorts. Patients treated with amisulpride, typical antipsychotics and risperidone were significantly more likely to have sexual related dysfunctions and/or amenorrhea. Increases in weight and body mass index occurred in all cohorts, but were significantly greater in the olanzapine and clozapine cohorts. Patients treated with olanzapine, quetiapine and clozapine had better tolerability outcomes regarding EPS and sexual related dysfunctions compared with patients receiving risperidone, amisulpride and typicals. Patients treated with olanzapine and clozapine had higher weight increases than patients treated with risperidone, quetiapine and typicals.

Weight Gain During Long-Term Treatment of Obsessive-Compulsive Disorder

The effect of extended anti-depressant treatment on weight has been poorly investigated. Also unknown is whether different compounds have differential effects. The aim of the present study was to assess changes in weight in obsessive-compulsive disorder (OCD) patients treated for 2.5 years with clomipramine or selective serotonin reuptake inhibitors. 138 DSM-IV OCD patients who responded to 6-month acute treatment at the Mood and Anxiety Disorders Unit, Department of Neuroscience, University of Turin, Italy, were followed-up for 2 years while receiving open-label clomipramine, citalopram, fluoxetine, fluvoxamine, paroxetine, or sertraline. Patients were consecutively recruited and followed from May 1998 to March 2003. The mean percentage change in weight was compared for each group, as was the proportion of patients who had a > or = 7% weight increase from baseline. At the end of the 2.5-year study period, patients had gained a mean of 2.5% of their body weight with respect to baseline (1.58 kg); 14.5% of the total sample experienced a significant (> or = 7%) weight increase. Within each but the fluoxetine treatment group, paired t tests showed a significant increase in weight from baseline to final visit. Analysis of variance showed a significant difference between treatment groups (p = .009), with clomipramine being associated with the highest weight increase and fluoxetine and sertraline with the lowest. A higher proportion of clomipramine-treated patients (34.8%) gained > or = 7% in weight as compared with sertraline and fluoxetine, which accounted for the lowest percentage of patients with a significant weight gain (4.5% and 8.7%, respectively), although this difference was not statistically significant. Risk of weight gain during extended serotonin reuptake inhibitor treatment for OCD differs depending on which compound is used. The differences among antiobsessive drugs may affect compliance with medication and health risks.

Bradykinin release from high molecular weight kininogen and increase in plasma kallikrein-like activity following sensory stimulation by food in the rat.

Cephalic stimulation by food elicits, among other responses, dilatation of mesenteric blood vessels preparatory for digestion. The possible participation of bradykinin (BK), a powerful endogenous vasodilator, in this response was studied in fasted rats prior and following stimulation by sight and scent of food (sensory stimulation, SS), actual ingestion being denied to the animals. BK content of plasma high (HK) and low molecular weight kininogen (LK) was determined by bioassay on the atropinized, antihistamine-treated isolated guinea-pig ileum following release by trypsin from heat/acid denatured plasma. BK corresponding to LK was estimated in plasma which prior to denaturation had been incubated with kaolin, a process which leads to quantitative release and inactivation of BK from HK, but does not affect LK. BK corresponding to (HK + LK) was determined in plasma not exposed to kaolin. BK contained in HK was the difference between BK of (HK + LK) and of BK of LK. Plasma and glandular kallikreins were estimated by fluorimetry, using specific synthetic substrates. A 40.6+/-4.0% decrease (P<0.001) of BK in HK occurred in rats after 90 s of SS; LK remained unaffected. Ten minutes of SS did not result in further change. Atropine inhibited the effect of SS. Return of HK to pretreatment levels occurred when, following 90s of SS, rats were allowed to rest for 60 min in the absence of food. Renewed capacity to respond to SS was then observed. Plasma kallikrein, but not glandular kallikrein, increased in plasma of rats after SS. Increased free BK was detected in the circulation of Enalapril-protected rats after SS. Electrical stimulation of the distal sector of the sectioned left abdominal vagus nerve of Nembutal-anesthetized fasted rats reproduced the effect of SS on HK. It is concluded that visuo-olfactory stimulation by food generates nerve impulses, possibly carried by the vagus nerve, which by activating plasma kallikrein lead to cleavage of circulatory HK and release of BK in the rat.

Desenvolvimento de Supputius cincticeps (Heteroptera, Pentatomidae) alimentado com larvas de Zophobas confusa, Tenebrio molitor (Coleoptera, Tenebrionidae) e Musca domestica (Diptera, Muscidae)

Egg viability and nymphal development of the predatory bug Supputius cincticeps (Stal, 1860) were evaluated during two generations in the Biological Control Laboratory of the Nucleo de Biotecnologia Aplicada a Agropecuaria (Bioagro/UFV) in Vicosa (Minas Gerais, Brazil) at 24.72±1.10oC and photophase of 12 hours. Three treatments were represented by S. cincticeps fed with Zophobas confusa Gebien, 1906, Tenebrio molitor Linnaeus, 1758 and Musca domestica Linnaeus, 1758 larvae. Higher egg viability of this predator was found when the preys were Z. confusa and T. molitor, 74.46% and 80.91 %, than in M. domestica, 57.02%, but incubation period showed no differences between preys. Shorter nymphal development and higher nymphal viability were found with Z. confusa and T. molitor than with M. domestica. Higher weight increase was found for nymphs which originated males and females in the second generation specialy with the first two preys.

Abnormal degradation of von Willebrand factor main subunit in pulmonary hypertension

We wished to investigate whether the abnormalities in multimeric structure and biological function of von Willebrand factor (vWF) observed in pulmonary hypertensive patients could be related to increased proteolytic degradation. We therefore analysed plasma vWF subunit composition in 24 pulmonary hypertensive patients, aged 1.2-45 yrs. After immunoisolation, vWF was subjected to 5.5% sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western immunoblotting, vWF intact subunit (225 kDa) and four proteolytic fragments (189, 176, 150 and 140 kDa) were visualized by peroxidase staining and analysed in a laser densitometer. In pulmonary hypertensive patients, the relative density of the intact subunit was decreased, and this was associated with an increase in the 176 kDa proteolytic fragment. The mean densities of the other fragments were not significantly changed, but in some patients the 150 and 140 kDa polypeptides were markedly increased. Abnormalities in multimeric structure of vWF (loss of high molecular weight multimers and increase in low molecular weight forms in comparison with controls), were associated with a significant decrease in biological activity (62-92% activity, 95% confidence interval (CI) for the mean). Total proteolytic fragment density correlated positively with multimeric abnormalities (rs = 0.45), and negatively with biological activity of vWF (rs = -0.49). Thus, in pulmonary hypertension, multimeric abnormalities and decreased biological activity are related to proteolytic degradation of vWF main subunit, possibly reflecting extensive endothelial dysfunction.