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Biomedical subjects

H Hedelin

Publications and source records attributed to H Hedelin.

At least 91 records · Page 5Linked to original sources
PubMed1985

Abdominal injuries in children: an analysis of 348 cases.

Three hundred and forty-eight children from Skaraborg County, Sweden, admitted to hospital with abdominal injuries over a 30-year period (1951-1980), have been analysed and compared with all patients with abdominal injury (1407) admitted to hospital from the same area during the same period. The number of children admitted in the second half of the period was greater than during the first but the proportion of children compared with adults was considerably reduced. During the period abdominal injuries due to car accidents increased in adults but not in children. The most frequent cause of abdominal injury in children was a bicycle accident. Abdominal injury due to sport also increased over the period. Mortality decreased, with no deaths in the past 10 years, compared with 8.6 per cent mortality in the first 10 years of the period.

Abdominal Injuries↗
PubMed1985

Urease-induced crystallization in synthetic urine.

The urease-induced crystallization of magnesium ammonium phosphate and calcium phosphate was studied at different alkalinization degrees by incubating synthetic urine with increasing Jack Bean urease concentrations. The crystallization was studied as precipitation on glass rods immersed in synthetic urine. The calcium phosphate precipitation on the glass rods occurred when the pH reached 6.8. Magnesium ammonium phosphate precipitation occurred when the pH reached 7.0. The maximal crystallization occurred at a pH between 7.5 and 8.0; at higher pHs the precipitation was considerably lower. The possible mechanisms and clinical implications behind this narrow pH optimum for urease-induced crystallization, which also have important implications for future experimental studies, are discussed.

Calcium Phosphates↗
PubMed1985

Factors influencing the time long-term indwelling Foley catheters can be kept in situ.

To study the factors that influence the frequency of unscheduled catheter changes, patients with long-term indwelling Foley catheters were followed up for 48 weeks. A marked interindividual difference in the need for unscheduled changes was noted. The amount and composition of the encrustations precipitated on the catheters and urine osmolality influenced the frequency of unscheduled catheter changes. There was no correlation between the time a catheter had been in situ and the amount of encrustations on catheters changed on schedule after various times in situ. This indicates that time does not govern the amount of encrustations accumulated.

Adult↗
PubMed1985

The severity of infection stones compared to other stones in the upper urinary tract.

A retrospective study of the case records of 391 adult patients with spontaneously passed or surgically removed concrements from the upper urinary tract during the period 1982-1983 was performed. According to chemical analysis, 66% of the stones were calcium stones, 30% were infection stones, 4% were uric acid/urate stones and 1% were cystine stones. Of the infection stones 12 (10%) were staghorn calculi. The infection stones placed a greater strain on the patients than the calcium stones. Thus, infection stones were significantly more often recurrent stones and required surgery significantly more often than the calcium stones. Only 6% of the patients with infection stones had proved abnormalities predisposing to upper urinary tract infection. Urinary tract infection with a urease-producing microorganism was detected in only 52% of the patients with infection stones. As infection with a urease-producing microorganism is a prerequisite for the formation of infection stones in the urinary tract a careful microbiological investigation to find and treat the infection responsible for the stone formation is mandatory.

Adolescent↗
PubMed1984

Effects of tranexamic acid and local fibrin deposition of fibrinolysis and granulation tissue formation in preformed cavities.

The effects of locally deposited fibrin and of tranexamic acid-induced antifibrinolysis on forming granulation tissue were studied in the light of a recently developed method for treatment of postoperative fistulas by occlusion with a fibrin clot. Perforated teflon cylinders, either empty or fibrin-filled, were implanted subcutaneously in rats and extracted after 2 weeks. Fibrin deposition was found to stimulate granulation tissue ingrowth into the cylinders but it did not change the fibrinolytic activity in the granulation tissue. A significantly higher fibrinolytic activity was, however, found in the tissue fluid collected from the space between the granulation tissue and the implanted fibrin clot compared to tissue fluid from cylinders implanted empty. Tranexamic acid significantly reduced the fibrinolytic activity on the granulation tissue and delayed lysis of the implanted fibrin clot. It also reduced granulation tissue ingrowth but it did not abolish the positive effects of the clot on granulation tissue formation.

Animals↗
PubMed1984

Ureaplasma urealyticum-induced crystallization of magnesium ammonium phosphate and calcium phosphates in synthetic urine.

Crystallization of struvite and calcium phosphates was studied in vitro as encrustations on glass rods immersed in synthetic urine, to evaluate the crystallization capacity of Ureaplasma urealyticum and compare it with that of known urease and non-urease-producing bacteria. Inoculation of the synthetic urine with Ureaplasma urealyticum resulted in alkalinization of the synthetic urine and crystallization of struvite and brushite. Inoculation with Proteus mirabilis caused a faster and more pronounced alkalinization as well as crystallization of struvite and apatite. The alkalinization and crystallization caused by Ureaplasma urealyticum and Proteus mirabilis was completely prevented by acetohydroxamic acid, a potent urease inhibitor, linking the crystallization to the urease activity of the microorganisms. When the synthetic urine was inoculated with urease-negative Escherichia coli no alkalinization and no crystallization were seen.

Calcium Phosphates↗
PubMed1984

Ureaplasma urealyticum and upper urinary tract stones.

The occurrence of bacteria and Ureaplasma urealyticum in the upper urinary tract was studied in 50 patients operated on for renal stones. Cultures were performed on voided urine, pelvic urine obtained during surgery and the stone. The chemical composition of the stones was analysed. Twenty-six stones were of metabolic origin and 24 infection-induced, i.e. composed of struvite and/or carbonate-apatite. Ureaplasma urealyticum was cultured from the upper urinary tract in 1 patient with metabolic stones, and in 7 with infection stones. In 4 of these 7 patients no other urease-producing micro-organism was detected, suggesting that Ureaplasma urealyticum may have been associated with stone formation in these patients.

Adult↗
PubMed1984

The composition of catheter encrustations, including the effects of allopurinol treatment.

The composition of encrustations precipitated on long-term indwelling urethral catheters was analysed using a newly developed wet chemical method that allows determination of small sample volumes. In contrast to earlier studies, the major portion of the encrusted material could be identified; ammonium magnesium phosphate and calcium phosphates (brushite and apatite) were the major components. The effect of allopurinol was also investigated and it was found to decrease significantly the amounts of urate and calcium phosphate but not to lower significantly the total amount of material precipitated on the catheters.

Allopurinol↗
PubMed1983

Patients with abdominal trauma and fatal outcome: analysis of a 30-year series.

Patients with blunt abdominal trauma and fatal outcome during 30 years in a well-defined rural Swedish area have been analyzed. There were 127 patients. Several facts indicate that more severe trauma has been appearing more often during this period The mortality rate has, however, been stable, but the patients have become older. More patients die from pulmonary complications than from the trauma itself. One very important development is the significant decrease in mortality among children.

Abdominal Injuries↗
PubMed1983

Influence of local fibrin deposition on granulation tissue formation. A biochemical study in the rat.

A recently developed method for occlusion of fistulas with a fibrin clot initiated studies of the effects of deposited fibrin on granulation tissue formation. Perforated Teflon cylinders, empty or fibrin-filled, were implanted subcutaneously in rats for 2, 3 and 4 weeks and the composition of the ingrowing granulation tissue was followed by sequential biochemical analysis. The concentration of fat and water and the cellularity, measured as DNA concentration, were the same throughout the period studied in the granulation tissue from cylinders implanted empty and fibrin filled. After 2 weeks of implantation, the collagen concentration was higher in fibrin-filled cylinders than in cylinders implanted empty. The higher collagen concentration was explained by a higher proportion of mature collagen-synthesising cells. After 3 and 4 weeks of implantation there was no difference in the collagen concentration between cylinders implanted empty and fibrin filled.

Acid Phosphatase↗
PubMed1983

Blunt renal trauma. Analysis of 417 patients.

Case records of 417 patients, from a well-defined area, who were hospitalized because of blunt renal trauma during the period 1950-1979 were analyzed. The incidence increased during the final decade, corresponding to a rising incidence of motor traffic accidents and sports injuries. Young patients, between 10 and 29 years of age, were responsible for the increase and half of all patients were in this age group. Associated injuries were frequent. Emergency urography was rare during the earlier part of the investigation period, but the frequency increased strongly thereafter. Treatment was mainly conservative (nonoperative) except in patients with major renal injuries. Nephrectomy was performed in 22 patients. Reconstructive surgery was performed especially in patients with intermediate renal injuries during the final decade. The total mortality was 6.5%. Only 7 patients (1.7%) died from the renal injury. A dramatic reduction in the hospitalization time was noted.

Accidents, Traffic↗
PubMed1983

The influence of locally deposited fibrin on the biomechanical properties of developing granulation tissue in rats.

A recently developed method for the occlusion of fistulas with a fibrin clot has stimulated studies concerning the effects of deposited fibrin on the formation of granulation tissue (g.t.). In this study the influence of artificially implanted fibrin on the biomechanical properties of developing g.t. was investigated in rats. Perforated Teflon cylinders either empty or fibrin filled, were implanted subcutaneously for two weeks. The g.t. from fibrin filled cylinders was found to adhere significantly better to the cylinder walls which is an important property in the case of fistula closure with fibrin. Mechanical testing, however, showed that the maximum load and the maximum strain were significantly higher in cylinders implanted empty. However, the collagen concentration was no higher in cylinders implanted empty suggesting that in the newly formed g.t. studied, factors other than the collagen concentration determined the strength of the tissue.

Animals↗
PubMed1983

Bacterial colonization of the lower urinary tract in women with long-term indwelling urethral catheter.

The bacterial colonization of urethra and urine was studied over long periods in 16 hospitalized women with long-term indwelling bladder catheter. The cultured flora was polymicrobic and, except for Proteus mirabilis and Escherichia coli, rapidly changing. The colonization patterns showed marked inter-species variations. P. mirabilis was the species most commonly found, and in the urethra it was significantly more persistent than the other species. Unlike the other species, P. mirabilis was rarely found in urine without concomitant urethral growth. Prophylactic measures aimed to reduce the risk of permanent colonization by this pathogen, which is rendered particularly harmful by its urease production, should therefore be directed towards the urethra and the periurethral area.

Adult↗
PubMed1982

Abdominal injury from sporting activities.

The frequency of abdominal injury is rising. In an analysis of 1,354 cases of closed abdominal trauma sustained during a 30-year period (1950-1979) in Skaraborg County, Sweden, a distinct increase was found in the numbers associated with sporting activities. The severity of the injuries caused by sports likewise showed an increase. The representation of injured organs was of the same order as in the total series of closed abdominal injuries. An analysis of the 136 cases of sports-associated injury is presented with regard to cause and type of the injuries, diagnosis and prognosis.

Abdominal Injuries↗
PubMed1982

Influence of fibrin clots on development of granulation tissue in preformed cavities.

To examine the influence of fibrin clots, perforated Teflon cylinders have been implanted subcutaneously in rats. Fibrin clots made from both species specific fibrinogen and from an non-species specific preparation, together with ingrowing granulation tissue, kept the implanted cylinder filled during the four week study period. This was valid for both concentrations investigated. Interaction between granulation tissue and fibrin clot differed between the two fibrin types.

Animals↗