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Biomedical subjects

J Bergström

Publications and source records attributed to J Bergström.

At least 73 records · Page 4Linked to original sources

Helicobacter pylori and neutrophils: sialic acid-dependent binding to various isolated glycoconjugates.

Helicobacter pylori has been shown to agglutinate erythrocytes in a sialic acid-dependent manner. However, very few studies have examined relevant target cells in the human stomach. Neutrophils are required for the onset of gastritis, and the inflammatory reaction may be induced on contact between bacteria and neutrophils. In the present work, glycolipids and glycoproteins were isolated from neutrophils and were studied for binding by overlay with radiolabeled bacteria on thin-layer chromatograms and on membrane blots. There was a complex pattern of binding bands. The only practical binding activity found was sialic acid dependent, since treatment of glycoconjugates with neuraminidase or mild periodate eliminated binding. As shown before for binding to erythrocytes and other glycoconjugates, bacterial cells grown on agar bound to many glycoconjugates, while growth in broth resulted in bacteria that would bind only to polyglycosylceramides, which are highly heterogeneous and branched poly-N-acetyllactosamine-containing glycolipids. Approximately seven positive bands were found for glycoproteins, and the traditional ganglioside fraction showed a complex, slow-moving interval with very strong sialic-acid-dependent binding, probably explained by Fuc substitutions on GlcNAc.

Chromatography, Thin Layer↗

Effect of protein intake on plasma and erythrocyte free amino acids and serum IGF-I and IGFBP-1 levels in rats.

Amino acid (AA) levels in plasma and erythrocytes (RBC) were determined in rats (n = 29) fed diets with 6, 21, and 35% protein, and their association with insulin-like growth factor I (IGF-I), insulin, or IGF-binding protein (IGFBP)-1 levels was studied. Free AA in plasma and RBC were determined by reversed-phase high-pressure liquid chromotography, and IGF-I, IGFBP-1, and insulin plasma levels were determined by RIA. Rats fed the low-protein (6%) diet were growth-retarded and had lower serum IGF-I levels and higher serum IGFBP-1 levels than the other two groups (P < 0.0001). In rats fed the low-protein diet, most of the nonessential AA (NEAA) in both plasma and RBC increased, whereas the essential AA (EAA), with the exception of threonine, decreased. When the groups were combined, both RBC and plasma EAA-to-NEAA ratios were positively correlated to IGF-I (r = 0.76 and 0.80, respectively; P < 0.0001) and inversely correlated to IGFBP-1 levels (r = -0.67, P < 0.001 and r = -0.78, P < 0.0001, respectively). A significant inverse correlation was found between RBC glutamate and IGF-I (r = -0.85, P < 0.0001, n = 25) and insulin (r = -0.72, P < 0.001, n = 21), and a positive correlation was found for IGFBP-1 (r = 0.78, P < 0.0001, n = 24). In multiple regression analysis, only IGF-I remained as an independent variable. Threonine was the only EAA with a significant inverse correlation to insulin (r = -0.66, P < 0.001). We hypothesize that AA metabolism is associated to changes in IGF-I, insulin, and IGFBP-1 levels in rats on different protein intakes.

Aging↗

Evidence of splanchnic-brain signaling in inhibition of ingestive behavior by middle molecules.

Anorexia, nausea, and vomiting are common symptoms of uremic intoxication. Fractions in the middle molecule weight range, isolated from normal urine and uremic plasma ultrafiltrate, inhibit ingestive behavior in the rat. To investigate their site of action and specificity, male rats were injected intraperitoneally, intravenously, or intracerebroventricularly with concentrated fractions of uremic plasma ultrafiltrate or normal urine (molecular weight range: 1.0 to 5.0 kD) and tested for ingestive and sexual behavior. An intraperitoneal injection of 0.5 ml of urine fraction (10:1) or 2.0 ml of uremic plasma ultrafiltrate fraction (25:1) inhibited carbohydrate intake by 76.3 and 45.9%, respectively, but an intravenous injection had no effect. However, intravenous injection of higher doses inhibited carbohydrate ingestion. An intracerebroventricular injection of 5 or 10 microl of urine (20:1) middle molecule fraction inhibited carbohydrate intake by 13.4 and 41.6%, respectively. An injection of 5 or 10 microl of uremic plasma ultrafiltrate (125:1) middle molecule fraction inhibited carbohydrate intake by 22.6 and 49.5%, respectively. Injections of the corresponding fraction from normal plasma ultrafiltrate had no effect. Injection of urine or uremic plasma ultrafiltrate middle molecule fractions did not affect the display of sexual behavior. These results suggest that middle molecule fractions from uremic plasma ultrafiltrate or normal urine act in the splanchnic region and/or brain to inhibit food intake and that the effect is specific for ingestive behavior.

Animals↗

Effects of high-dose folic acid and pyridoxine on plasma and erythrocyte sulfur amino acids in hemodialysis patients.

In this investigation, sulfur amino acids (sAA) and sulfhydryls were determined in the plasma and erythrocytes (RBC) of 10 uremic patients on regular hemodialysis (HD) treatment and 10 healthy subjects, before and after supplementation with 15 mg/d of folic acid and 200 mg/d of pyridoxine for 4 wk. The basal total plasma concentrations of homocysteine (Hcy), cysteine (Cys), cysteinylglycine (Cys-Gly), gamma-glutamylcysteine (gamma-Glu-Cys), glutathione (GSH), and free cysteinesulfinic acid (CSA) were significantly higher in HD patients when compared to healthy subjects, whereas methionine (Met) and taurine (Tau) concentrations were the same in the two groups. HD patients showed significantly higher RBC levels of Hcy and Cys-Gly, whereas the RBC concentrations of Met, Cys, Tau, and GSH were not different from those in the healthy subjects. The plasma concentrations of sAA and sulfhydryls differed compared with RBC levels in the healthy subjects and HD patients. In both groups, supplementation with high doses of folic acid and pyridoxine reduced the plasma Hcy concentration. In addition, increased plasma concentrations of Cys-Gly and GSH were found in the HD patients and of CSA in the healthy subjects. After vitamin supplementation, the RBC concentrations of Hcy, Cys, and GSH increased and that of Tau decreased in healthy subjects. The only significant finding in RBC of HD patients was an increase in GSH levels after supplementation. This study shows several RBC and plasma sAA and sulfhydryl abnormalities in HD patients, which confirms earlier findings that RBC and plasma pools play independent roles in interorgan amino acid transport and metabolism. Moreover, high-dose supplementation with folic acid and pyridoxine significantly reduced Hcy levels, but did not restore the sAA and sulfhydryl abnormalities to normal levels. The increase that was observed in GSH after vitamin supplementation may have a beneficial effect in improving blood antioxidant status in uremic patients. Finally, the findings of elevated plasma Cys levels correlating to the elevated plasma Hcy levels in the presence of elevated plasma CSA levels, both before and after vitamin supplementation, led to the hypothesis that a block in decarboxylation of CSA is linked to hyperhomocysteinemia in end-stage renal failure.

Adult↗

Physiological saline is not a biocompatible peritoneal dialysis solution.

UNLABELLED: We have previously demonstrated that daily exposure to dialysis fluid results in significantly increased peritoneal lymphatic flow. In this study, we investigated if daily intraperitoneal infusion of saline (isotonic, glucose free) could cause similar changes. METHODS: Sixteen male SD rats received daily infusion (i.p.) of 20 ml saline for ten days (Saline group). Twenty-four hours after the last infusion, a 4 hour dwell study using 25 ml 3.86% glucose dialysis solution with frequent dialysate and blood sampling was done in each rat as well as in rats which did not receive daily infusion (Control, n=8). Radiolabeled human albumin (RISA) was added to the solution as an intraperitoneal volume marker. Radioactivity, glucose, urea, sodium, and potassium were measured for each sample. In a separate study, the RISA absorption to peritoneal tissue was also determined. RESULTS: The net ultrafiltration was significantly decreased in the daily infusion group (p<0.05). However, the apparent volume at 3 minutes of the dwell was markedly increased; this was due to a significant increase in the RISA binding (1.5-12.0% in the Saline group vs. 0.45-1.12% in the Control group) to peritoneal tissues as assessed by measurement of RISA recovery at 3 min of the dwell. This resulted in a significant overestimation both of the intraperitoneal volume (IPV) at 3 min and the (apparent) fluid absorption rate (as estimated by the transport of RISA out of peritoneal cavity): 0.087+/-0.026 ml/min in the Saline group vs. 0.052+/-0.007 ml/min in the Control group, p<0.001. The direct lymphatic flow as estimated by the clearance of RISA to plasma (which should not be affected by the RISA binding) also increased markedly (0.021+/-0.005 ml/min in the Saline group vs. 0.008+/-0.001 ml/min in the control group). There was no significant difference in the D/P values for small solutes (urea, sodium, potassium, urate) and D/D0 for glucose between the two groups. CONCLUSIONS: 1) Daily infusion of physiological saline into peritoneal cavity may increase the peritoneal lymphatic flow; 2) The significant (apparent) increase in IPV shortly after infusion may suggest increased RISA binding to peritoneal tissues (which may be related to the damage of the tissues, and results in overestimation of the peritoneal fluid absorption rate); 3) Saline is not a biocompatible peritoneal dialysis solution, and should therefore not be used as a control or flush solution.

Absorption↗

Activation of human B-lymphocytes by Prevotella intermedia.

Black pigmented Gram negative Prevotella intermedia is a potential pathogenic bacterium in periodontal disease. Lipopolysaccharides (LPS) from Gram negative bacteria are the main antigens that stimulate antibody production and cytokine synthesis. Many reports indicate a strong correlation of specific antibodies of the immunoglobulin G (IgG) class with antigens of periopathogenic bacteria in periodontal disease. The aim of this study was to measure lymphocyte proliferation and immunoglobulin (IgA, IgG and IgM) production from B-lymphocytes in response to P. intermedia stimulation. P. intermedia was originally isolated from human periodontal pockets by means of a gingival crevice lavage method. The periodontal pocket was washed with salt solution and the solution was then aspirated into a cannula for further culturing in the laboratory. The identification of P. intermedia was made on Brucella agar. Lymphocytes were isolated from human peripheral blood. P. intermedia was added to the lymphocytes in concentrations from 0.005% to 0.1%. The immunoglobulin production was measured by enzyme-linked immunosorbent assay (ELISA). The results showed that IgA and IgG were produced in response to stimulation with P. intermedia. The IgG response was dose-dependent. No stimulation of IgM production was obtained. It is concluded from the present observations that P. intermedia can stimulate proliferation of lymphocytes and production of IgA and IgG.

Antibodies, Bacterial↗

Intraperitoneal addition of hyaluronan improves peritoneal dialysis efficiency.

BACKGROUND: It has been shown that hyaluronan (HA) can decrease peritoneal fluid absorption. It is not known, however, how various molecular weights and various concentrations of hyaluronan affect peritoneal fluid absorption rate. METHODS: A study of 4-hour dwells, with frequent dialysate and blood sampling, was performed in male Sprague-Dawley rats (6-7 rats in each group) with 131I albumin as an intraperitoneal volume marker. Each rat was infused intraperitoneally with 25 mL of 1.5% glucose solution alone or 1.5% glucose solution containing hyaluronan at various molecular weights (MW-85 kD, 280 kD, 500 kD, and 4 MD) or containing hyaluronan of MW 500 kD at various concentrations (0.01%, 0.05%, 0.1%, 0.5%). Two additional groups were infused with 40 mL of 1.36% glucose dialysate alone or 1.36% glucose dialysate with 0.01% hyaluronan (MW 500 kD) to test the effect of hyaluronan when high dialysate fill volume was used. RESULTS: Addition of 0.01% hyaluronan significantly decreased peritoneal fluid absorption rate (K(E)) (by 22%, p < 0.01). The decrease was more marked with hyaluronan at high MW or high concentration, or with high dialysate fill volume. The net ultrafiltration tended to be higher in all hyaluronan groups compared to their control groups except in the 4 MD group; this difference was mainly due to a lower K(E) in all the hyaluronan groups. The direct lymphatic flow was significantly decreased in the 0.5% HA group. The transcapillary ultrafiltration rate (Qu) was significantly lower in the 4 MD group as compared to the control group. No difference in Qu was found between the other groups as compared to their control groups. CONCLUSIONS: (1) Intraperitoneal addition of hyaluronan may increase net peritoneal fluid removal, mainly because hyaluronan decreases peritoneal fluid absorption rate. The decrease was more marked when high dialysate fill volume was used, indicating that intraperitoneal addition of hyaluronan can prevent the decreased net ultrafiltration caused by an increase in dialysate fill volume. (2) The decrease in peritoneal fluid absorption rate may be both MW-dependent and concentration-dependent: that is, a higher MW as well as a higher concentration of hyaluronan result in a more marked decrease in peritoneal fluid absorption rate. (3) Low concentrations of high MW hyaluronan may also decrease Qu. However, Qu did not decrease when high concentrations of hyaluronan were used despite a significant decrease in peritoneal fluid absorption rate.

Absorption↗

A simple and fast method to estimate peritoneal membrane transport characteristics using dialysate sodium concentration.

BACKGROUND: The peritoneal equilibration test (PET) is widely used to classify a patient's peritoneal transport characteristics. However, PET is laborious and the prediction of fluid removal based on PET is generally poor. It is believed that osmosis by glucose occurs partially through transcellular water channels, resulting in sieving of sodium and decrease of dialysate sodium concentration when using hypertonic glucose dialysate. OBJECTIVE: In this study, we investigated the possibility of using dialysate sodium concentration to classify the patient's peritoneal transport characteristics. METHODS: A 6-hour dwell study with frequent dialysate and plasma sampling was performed in 46 patients using 2 L of 3.86% glucose dialysate with 131I-albumin as an intraperitoneal volume (IPV) marker. The peritoneal transport of sodium, creatinine, glucose, and fluid was evaluated. RESULTS: The dialysate sodium concentration at 240 min (D(Na240)) significantly correlated with D/P creatinine (r = 0.76, p < 0.001) and D/D0 glucose (r = -0.83, p < 0.001) at 240 min of the dwell (better than dialysate sodium concentration at any other time of the dwell). DNa240 also significantly correlated with IPV at 240 min of the dwell (r = -0.61, p < 0.001)(better than D/P creatinine and D/D0 glucose). There were significant correlations between D(Na240) and the sodium-sieving coefficient (r = 0.71, p < 0.001) and the diffusive mass transfer coefficient for sodium (r = 0.50, p < 0.001). When using D(Na240) to divide the patients into four groups, as in the PET method, no significant difference was found between the two methods. CONCLUSION: Using 3.86% glucose solution, D(Na240) can be used instead of D/P creatinine to classify patients into different transport groups. D(Na240) provides a better prediction of peritoneal fluid transport and reflects both the diffusive and convective transport properties of the membrane. As only one dialysate sample (and no blood sample) is needed, D(Na240) may offer important clinical advantages compared with PET.

Biological Transport↗

Influence of hemodialysis on intravascular volume and vasoactive hormones.

BACKGROUND: The posthemodialysis plasma level of atrial natriuretic peptide (ANP) has been proposed as an index for an adequate fluid state in hemodialysis (HD) patients. PATIENTS AND METHODS: We investigated the effect of fluid removal during HD on the interaction between intravascular volume and the vasoactive hormones ANP, vasopressin, adrenaline, noradrenaline, renin and aldosterone in 16 HD patients. Intravascular volume was examined with the 131I-labeled albumin method for blood volume (BV) and ultrasound for measurement of inferior vena cava diameter (IVCD). RESULTS: There was a significant decrease in BV, IVCD and ANP, but not in the other vasoactive hormones. Based on BV and IVCD measurements, the predialysis plasma ANP levels in the normovolemic and hypovolemic patients were significantly higher than in the hypervolemic patients. There was no significant difference between the postdialysis ANP levels in the hypervolemic and normovolemic patients and no significant correlations between ANP and BV and IVCD, respectively, but postdialysis ANP correlated significantly with the ultrafiltration rate (r = -0.51, p < 0.05), noradrenaline (r = 0.54, p < 0.05) and change in vasopressin (r = -0.50, p < 0.05). There were also correlations between ANP and age before HD (r = 0.50, p < 0.05) and after HD (r = 0.70, p < 0.0025). CONCLUSION: We conclude that the usefulness of the plasma ANP level for assessment of the fluid state in HD patients is limited, since age and other factors than those directly related to volume influence the concentration of ANP.

Adult↗

Peritoneal fluid kinetics: comparison between polyglucose solution and albumin solution.

Polyglucose (PG) solution has been shown to be capable of inducing peritoneal ultrafiltration despite its hypo-osmolality. However, the mechanism of osmosis by PG is not clear. In this study, we compared the fluid kinetics of albumin (ALB) solution (thought to be an ideal solution that should induce ultrafiltration through colloid osmosis) and PG solution. A 4-hour dwell study with frequent sampling was conducted in Sprague-Dawley rats (six rats in each group). The study used 25 mL of dialysate buffer, 10% ALB dialysis solution, 15% ALB dialysis solution, 20% ALB dialysis solution, or 7.5% PG solution, with 131I albumin as an intraperitoneal volume marker. All solutions were prepared by adding ALB or PG to a base dialysis solution (without osmotic agent). The initial osmolality values of the five solutions were 250 mOsm/kg, 284 mOsm/kg, 300 mOsm/kg, 320 mOsm/kg, and 280 mOsm/kg, and the dialysate drainage volumes at 4 hours were 17.0 +/- 0.8 mL, 22.4 +/- 0.8 mL, 25.4 +/- 0.6 mL, 27.3 +/- 0.9 mL, and 26.3 +/- 0.6 mL (buffer, 10% ALB, 15% ALB, 20% ALB, and 7.5% PG groups, respectively). The higher initial osmolality in the ALB groups was partially due to the sodium content in the ALB powder. The intraperitoneal volume was decreasing in the 10% ALB group, rather stable in the 15% ALB group, but slowly increasing in the 20% ALB group. In the PG group, intraperitoneal volume decreased initially and then started to increase after 2 hours. This pattern was closely related to the increase in the dialysate osmolality (to higher than plasma level). At 4 hours, the dialysate osmolality was significantly higher (and higher than plasma level) in the PG group as compared to all the ALB groups. No differences in peritoneal fluid absorption rate were observed among the four treatment groups. In the 15% ALB and 20% ALB groups, the transcapillary ultrafiltration rate (Qu) was lower in the later part of the dwell than in the initial part of the dwell; in the PG group, the opposite pattern was observed. Our results suggest that the osmosis of albumin dialysis solution is different from the osmosis of polyglucose solution. Polyglucose solution induces net ultrafiltration only when the dialysate osmolality increase to higher than plasma level, suggesting that degradation of polyglucose may be important for effective ultrafiltration.

Albumins↗

Vasodilatation by intraperitoneal addition of nitroprusside is not a model for high peritoneal transport.

It has been suggested that the peritoneal capillary is the major determinant for peritoneal fluid transport and that an increase in the number of peritoneal capillaries may be the reason for an increased peritoneal transport rate. In this study, we investigated the impact on peritoneal fluid and solute transport of vasodilatation (which may increase the number of perfused capillaries) by intraperitoneal addition of nitroprusside. A 4-hour dwell was performed in four groups of Sprague-Dawley rats (4-8 rats in each group) with 131I albumin as an intraperitoneal volume marker. Nitroprusside at concentrations of 0% (control), 0.0005%, 0.001%, and 0.002% was added to the 3.86% glucose solution before intraperitoneal infusion. Net ultrafiltration (NUF) was 13.2 +/- 0.6 mL, 14.5 +/- 0.7 mL, 13.4 +/- 0.9 mL, and 6.3 +/- 2.0 mL for the control group and the 0.0005%, 0.001%, and 0.002% nitroprusside groups, respectively. No significant differences in peritoneal fluid absorption rate (KE) were observed among the four groups. The intraperitoneal volume, transcapillary ultrafiltration rate (Qu), and peritoneal small-solute transport rate (glucose and urea) as assessed by diffusive mass transfer coefficient were significantly higher or tended to be higher in the 0.0005% nitroprusside group as compared to control. However, with further increase in the dose of nitroprusside, these parameters started to decrease as compared to the 0.0005% nitroprusside group, and NUF was significantly lower in the 0.002% nitroprusside group, conceivably suggesting a reduction in blood flow owing to the systemic effects of nitroprusside. Our study showed that: (1) a low dose of nitroprusside increased the peritoneal small-solute transport rate, but did not decrease peritoneal transcapillary ultrafiltration rate; (2) although a high dose of nitroprusside decreased peritoneal fluid removal, the decrease was not due to an increased small-solute transport rate, but more likely to a significant drop in peritoneal blood flow; (3) vasodilatation by nitroprusside did not change peritoneal fluid absorption rate. Overall, vasodilatation does not seem to produce a pattern of peritoneal fluid kinetics similar to that seen in high transporters, who have a higher peritoneal transport rate, lower transcapillary ultrafiltration rate, and higher peritoneal fluid absorption rate.

Animals↗

Glycosphingolipid binding specificities of Neisseria meningitidis and Haemophilus influenzae: detection, isolation, and characterization of a binding-active glycosphingolipid from human oropharyngeal epithelium.

The glycosphingolipid binding specificities of Haemophilus influenzae and Neisseria meningitidis were investigated as to the binding of radiolabeled bacteria to glycosphingolipids on thin-layer chromatograms. Thereby, similar binding profiles, for the binding of the two bacteria to lactosylceramide, isoglobotriaosylceramide, gangliotriaosylceramide, gangliotetraosylceramide, lactotetraosylceramide, neolactotetraosylceramide, and sialylneolactohexaosylceramide, were obtained. On a closer view the binding preferences of the bacteria could be differentiated into three groups. The first specificity is recognition of lactosylceramide. The second specificity is binding to gangliotriaosylceramide and gangliotetraosylceramide, since conversion of the acetamido group of the N-acetylgalactosamine of gangliotriaosylceramide and gangliotetraosylceramide to an amine prevented the binding of the bacteria, and thus the binding to these two glycosphingolipids represents a separate specificity from lactosylceramide recognition. Preincubation of H. influenzae with neolactotetraose inhibited the binding to neolactotetraosylceramide, while the binding to lactosylceramide, gangliotetraosylceramide, or lactotetraosylceramide was unaffected. Thus, the third binding specificity is represented by neolactotetraosylceramide, and involves recognition of other neolacto series glycosphingolipids with linear N-acetyllactosamine chains, such as sialyl-neolactohexaosylceramide. The relevance of the detected binding specificities for adhesion to target cells was addressed as to the binding of the bacteria to glycosphingolipids from human granulocytes, epithelial cells of human nasopharyngeal tonsils and human plexus choroideus. Binding-active neolactotetraosylceramide was thereby detected in human granulocytes and the oropharyngeal epithelium.

Animals↗

Blood pressure control in dialysis patients: importance of the lag phenomenon.

Failure by the world dialysis community to understand and use the dry-weight method of blood pressure (BP) control has resulted in an increasing incidence of treatment-resistant hypertension, which remains the principal cause of cardiovascular morbidity and mortality. This failure may in part be because the relationship between the extracellular volume (ECV) and BP is not simple and linear, but complex, because of a lag of several weeks between the normalization of the time-averaged ECV and the decrease in BP. Another cause for this failure may be the unwillingness to taper and stop all antihypertensive medications during the transition from hypertension to normotension. In this report, we describe in detail the lag phenomenon, document its presence during treatment in other populations, and describe how this knowledge is used in the application of the dry-weight method of drug-free BP control in the dialysis population.

Antihypertensive Agents↗

Malnutrition, cardiac disease, and mortality: an integrated point of view.

Malnutrition and hypoalbuminemia, which are prevalent in patients with end-stage renal disease (ESRD), are strong predictors of increased mortality. However, cardiovascular disease predominates among direct causes of death, whereas malnutrition appears to be of minor importance in this respect. Reports in the literature demonstrate that cardiac failure may cause malnutrition and that infection/inflammation may predispose to atherosclerosis as well as to catabolism and hypoalbuminemia. Proinflammatory cytokines, generated in response to cardiac failure, infection, and other inflammatory stimuli, appear to play a pivotal role by causing muscle wasting, hypoalbuminemia, and anorexia as well as reduced cardiac contractility and atherosclerotic vascular disease. We hypothesize that this scenario also applies to ESRD patients, in whom congestion, hypertension, cardiac failure, and ischemic cardiovascular disease are common. Malnutrition rarely may be the direct cause of death, except in elderly dialysis patients, but may contribute to a poor prognosis by aggravating pre-existing heart failure and increasing the susceptibility to infections.

Age Factors↗

Smoking and vascular density of healthy marginal gingiva.

The influence of smoking on the vascular characteristics in periodontally healthy individuals was studied over a period of 11 wk. Fourteen healthy female dental students, 7 smokers and 7 nonsmokers, aged 25 to 38 yr, volunteered for the experiment. Photodocumentation was performed on four occasions with the aid of a stereophotographic method. The characteristics of gingival vessels were evaluated according to a semi-quantitative vascular index. It was found that the vascular density was not statistically significantly different in smokers and nonsmokers. Furthermore, the vascular density remained stable in both smokers and nonsmokers. The results suggest that the vascular density of the marginal gingiva is uninfluenced by moderate smoking once healthy gingival conditions prevail.

Adult↗