The literature on tympanostomy tube treatment of children with recurrent and secretory otitis med... more The literature on tympanostomy tube treatment of children with recurrent and secretory otitis media was reviewed. The evidence for positive effects of tube treatment in secretory otitis media is ve ...
Ultrastructure of Endocrine Cells and Tissues, 1984
Even after almost 250 years of research the morphological and physiological interrelationship of ... more Even after almost 250 years of research the morphological and physiological interrelationship of the cellular elements of the carotid body are still poorly understood (1). The only function which has been confirmed is the capacity of the carotid body to act as a specific chemoreceptor.
International journal of pediatric otorhinolaryngology, Jan 11, 2002
Previous studies have shown that children with recurrent acute otitis media (rAOM) have significa... more Previous studies have shown that children with recurrent acute otitis media (rAOM) have significantly lower quantities of alpha-haemolytic streptococci (AHS) in the nasopharynx than healthy children. Furthermore children with otitis media have AHS with lower inhibitory activity in vitro on Streptococcus pneumoniae and non-typable Haemophilus influenzae compared with healthy children. A randomised, placebo controlled and double blind clinical study among children with rAOM was designed to determine whether or not a nasal spray, containing AHS with very good inhibitory activity on the three most common OM pathogens, could be an alternative to tympanostomy tube insertion. Forty three children under 4 years of age were included in the study. The children sprayed once daily for 4 months and were monitored for 6 months. Sixteen children in the active group and 20 children in the placebo group were evaluated. The result showed no significant differences regarding the number of episodes of ...
A telemedical pilot-project involving two rural primary health care centers in Tärnaby/Storuman i... more A telemedical pilot-project involving two rural primary health care centers in Tärnaby/Storuman in Southern Lappland and the University Hospital of Umeå was carried out during the period Sept. 1, 1996-Dec. 31, 1998. Out of 169 consultations in all, 40 pertained to dermatology, 50 to ENT, 40 to orthopedics, and a further 27 to other specialties (surgery, medicine and gynecology). Among the 169, 47 cases were successfully managed via telemedicine. 30% of consultations were made in order to secure a second opinion. The remaining 70% were made in order to seek advice concerning a possible referral. At the telemedical visit, patients indicated a satisfaction score of 5.5 on a scale up to 6.0. The GP's rated the educational value at 4.4. After completion of the pilot-project, a survey of acceptance and ratings of the future potential of telemedicine for the health care system was carried out among 191 doctors and other health care workers in Västerbotten county. Using a similar graded...
ORL; journal for oto-rhino-laryngology and its related specialties
The aim of the present experimental study was to elucidate the temporal development of myringoscl... more The aim of the present experimental study was to elucidate the temporal development of myringosclerosis. Twenty-four Sprague-Dawley rats were myringotomized bilaterally. At 3, 6, 9, 12, 18, 24, 30, 36, 48, 60, 72 and 84 h after the myringotomy, 2 animals at each time were examined otomicroscopically and thereafter sacrificed. The pars flaccida and pars tensa were excised and prepared for light- and electron-microscopic studies. Otomicroscopically, myringosclerosis was visible in the pars tensa 24 h after myringotomy, whereas no sclerotic lesions were noted in the pars flaccida. Histologically, sclerotic lesions were present in the pars tensa and pars flaccida 9 and 12 h, respectively, after myringotomy. The pars flaccida responds promptly with an inflammatory reaction characterized by abundant macrophages. Myringosclerosis develops promptly after myringotomy and its establishment is related to an inflammatory reaction.
The Annals of otology, rhinology, and laryngology, 1997
The present study was designed to establish whether or not an increased production of oxygen-deri... more The present study was designed to establish whether or not an increased production of oxygen-derived free radicals is involved in the causation of myringosclerosis. Sclerotic lesions in the tympanic membrane were experimentally elicited by keeping rats with perforated tympanic membranes in an atmosphere containing roughly 40% oxygen. The animals were treated daily with a solution containing either copper zinc-superoxide dismutase plus catalase, deferoxamine, or copper sulfate plus iron chloride, applied to the traumatized area. After 1 week the extension of myringosclerotic plaques was determined otomicroscopically. The pars tensa and pars flaccida were then dissected free and prepared for light microscopic studies. The results showed that treatment with copper zinc-superoxide dismutase plus catalase and deferoxamine inhibited or reduced the development of myringosclerosis, whereas the ears treated with copper sulfate plus iron chloride appeared unaffected. Consequently, the finding...
The Annals of otology, rhinology, and laryngology, 1993
Topically applied hydrocortisone was used to develop an animal model for persistent tympanic memb... more Topically applied hydrocortisone was used to develop an animal model for persistent tympanic membrane (TM) perforations. Hydrocortisone suspension was applied on the margins of TM perforations of standardized size in rats once daily for 10 days. The healing patterns of the TMs were mapped weekly and, when the perforations were about to close, daily. After 50 days, all hydrocortisone-treated perforations were open, whereas the controls closed within 9 to 12 days. At 3 months, when one third of the perforations still were open, the TMs were studied by otomicroscopy and light microscopy. All TMs were thickened and covered by keratin and wax. The thickened epidermal layer at the border of the TM perforations that remained open also draped the surface of the perforation facing the middle ear cavity. The thickened connective tissue layer contained abundant fibroblasts with their axes of length oriented at random. Both application of 1.4% hyaluronan and wounding of the perforation border e...
ORL; journal for oto-rhino-laryngology and its related specialties, 1994
Heparin, in concentrations of 250, 2,500 and 25,000 IU, was applied topically to the edge of tymp... more Heparin, in concentrations of 250, 2,500 and 25,000 IU, was applied topically to the edge of tympanic membrane (TM) perforations, standardized in size, once daily until the perforation had closed. At 2 months, the animals were killed and the TMs subjected to otomicroscopic and light microscopic studies. The day that closure of the TM perforations was complete (median 8 days) was the same for the various heparin groups as for the sterile water-treated controls. However, regarding opacity of the healed TM area, heparin affected the TM in a dose-dependent manner. The TMs that had been subjected to the highest concentration of heparin were the most transparent and showed the least sclerosis. When compared for thickness, the TMs treated with the higher concentration of heparin were considerably thinner than those treated with the lower concentration. The sterile water-treated controls were all thicker than the heparin-treated TMs. It is inferred that glycosaminoglycan heparin improves th...
Pharmacologic labyrinthectomy has become an alternative to surgery for treatment of severe Ménièr... more Pharmacologic labyrinthectomy has become an alternative to surgery for treatment of severe Ménièr's disease. The use of systemic streptomycin has been replaced by intratympanal instillations of gentamicin that are administered once daily for a limited number of days. Gentamicin provides a high success rate for ablation of vertigo without causing any unnecessary negative effects on hearing. Future development of more selective vestibulotoxic chemicals could mean that pharmacologic labyrinthectomy will become a simple and ultimate treatment for disabling Ménière's disease.
The Annals of otology, rhinology, and laryngology, 1995
The purpose of this study was to elucidate possible relationships between the oxygen concentratio... more The purpose of this study was to elucidate possible relationships between the oxygen concentration of the middle ear cavity and the development of myringosclerosis. Three groups of rats with myringotomized tympanic membranes were exposed to different oxygen concentrations of 10%, 15%, and 40%, respectively, for 1 week. A fourth group was kept in ambient air. Two other groups of rats with myringotomized and intubated tympanic membranes were exposed to oxygen concentrations of 10% and 40%, respectively, for the same period of time. Otomicroscopically, all hyperoxic animals had more numerous myringosclerotic lesions compared with the ambient air group, and also displayed a pronounced hyperplasia of the keratinizing epithelium around the perforation border. By contrast, the hypoxic animals showed less pronounced myringosclerotic lesions or even completely lacked them. It is inferred that an increased oxygen concentration in the middle ear cavity will increase the likelihood of myringosc...
International journal of pediatric otorhinolaryngology, 1984
Already within 24 h, splitting of the soft palate in rats caused production of effusion in the at... more Already within 24 h, splitting of the soft palate in rats caused production of effusion in the attic space. During the next couple of days the effusion material filled the meso- and hypotympanon. The production of a serous fluid in the attic space appeared concomitant with an elevated histamine content in the middle ear cavity, irrespective of whether the ears were ventilated or not. In the artificially ventilated middle ears no effusion appeared in the meso- and hypotympanon and the hypotympanal mucosal lining remained normal. The serous effusion filling the middle ear cavities with the intact tympanic membranes was replaced at about 7 days by a purulent effusion material containing mainly Gram-negative enteric rods. Thus it seems that a serous otitis media and a purulent otitis media occur in a continuum. The change to a purulent infection could be prevented by artificial ventilation, but as soon as the myringotomies were healed or the tympanostomy tubes got clogged a flocculent, ...
The aim of the present study was to experimentally provoke well-defined serous and purulent effus... more The aim of the present study was to experimentally provoke well-defined serous and purulent effusion materials and to analyze the fluid using cytological and immunochemical techniques. Using these parameters an attempt was made to find a marker(s) for the degree of inflammation, duration of the disease and possible sequelae.
The method of auditory evoked brainstem responses (AEBR) was applied on an animal model with two ... more The method of auditory evoked brainstem responses (AEBR) was applied on an animal model with two types of well defined middle ear effusions--serous otitis media (SOM) and purulent otitis media (POM). The animals with SOM exhibited fairly normal interpeak latencies but a considerably increased auditory threshold. In contrast, POM mainly affected the latencies of the brainstem evoked potential but also caused a slight increase of the auditory threshold. The results indicate that SOM chiefly causes a conductive hearing loss, while POM also affects the neural circuit.
The literature on tympanostomy tube treatment of children with recurrent and secretory otitis med... more The literature on tympanostomy tube treatment of children with recurrent and secretory otitis media was reviewed. The evidence for positive effects of tube treatment in secretory otitis media is ve ...
Ultrastructure of Endocrine Cells and Tissues, 1984
Even after almost 250 years of research the morphological and physiological interrelationship of ... more Even after almost 250 years of research the morphological and physiological interrelationship of the cellular elements of the carotid body are still poorly understood (1). The only function which has been confirmed is the capacity of the carotid body to act as a specific chemoreceptor.
International journal of pediatric otorhinolaryngology, Jan 11, 2002
Previous studies have shown that children with recurrent acute otitis media (rAOM) have significa... more Previous studies have shown that children with recurrent acute otitis media (rAOM) have significantly lower quantities of alpha-haemolytic streptococci (AHS) in the nasopharynx than healthy children. Furthermore children with otitis media have AHS with lower inhibitory activity in vitro on Streptococcus pneumoniae and non-typable Haemophilus influenzae compared with healthy children. A randomised, placebo controlled and double blind clinical study among children with rAOM was designed to determine whether or not a nasal spray, containing AHS with very good inhibitory activity on the three most common OM pathogens, could be an alternative to tympanostomy tube insertion. Forty three children under 4 years of age were included in the study. The children sprayed once daily for 4 months and were monitored for 6 months. Sixteen children in the active group and 20 children in the placebo group were evaluated. The result showed no significant differences regarding the number of episodes of ...
A telemedical pilot-project involving two rural primary health care centers in Tärnaby/Storuman i... more A telemedical pilot-project involving two rural primary health care centers in Tärnaby/Storuman in Southern Lappland and the University Hospital of Umeå was carried out during the period Sept. 1, 1996-Dec. 31, 1998. Out of 169 consultations in all, 40 pertained to dermatology, 50 to ENT, 40 to orthopedics, and a further 27 to other specialties (surgery, medicine and gynecology). Among the 169, 47 cases were successfully managed via telemedicine. 30% of consultations were made in order to secure a second opinion. The remaining 70% were made in order to seek advice concerning a possible referral. At the telemedical visit, patients indicated a satisfaction score of 5.5 on a scale up to 6.0. The GP's rated the educational value at 4.4. After completion of the pilot-project, a survey of acceptance and ratings of the future potential of telemedicine for the health care system was carried out among 191 doctors and other health care workers in Västerbotten county. Using a similar graded...
ORL; journal for oto-rhino-laryngology and its related specialties
The aim of the present experimental study was to elucidate the temporal development of myringoscl... more The aim of the present experimental study was to elucidate the temporal development of myringosclerosis. Twenty-four Sprague-Dawley rats were myringotomized bilaterally. At 3, 6, 9, 12, 18, 24, 30, 36, 48, 60, 72 and 84 h after the myringotomy, 2 animals at each time were examined otomicroscopically and thereafter sacrificed. The pars flaccida and pars tensa were excised and prepared for light- and electron-microscopic studies. Otomicroscopically, myringosclerosis was visible in the pars tensa 24 h after myringotomy, whereas no sclerotic lesions were noted in the pars flaccida. Histologically, sclerotic lesions were present in the pars tensa and pars flaccida 9 and 12 h, respectively, after myringotomy. The pars flaccida responds promptly with an inflammatory reaction characterized by abundant macrophages. Myringosclerosis develops promptly after myringotomy and its establishment is related to an inflammatory reaction.
The Annals of otology, rhinology, and laryngology, 1997
The present study was designed to establish whether or not an increased production of oxygen-deri... more The present study was designed to establish whether or not an increased production of oxygen-derived free radicals is involved in the causation of myringosclerosis. Sclerotic lesions in the tympanic membrane were experimentally elicited by keeping rats with perforated tympanic membranes in an atmosphere containing roughly 40% oxygen. The animals were treated daily with a solution containing either copper zinc-superoxide dismutase plus catalase, deferoxamine, or copper sulfate plus iron chloride, applied to the traumatized area. After 1 week the extension of myringosclerotic plaques was determined otomicroscopically. The pars tensa and pars flaccida were then dissected free and prepared for light microscopic studies. The results showed that treatment with copper zinc-superoxide dismutase plus catalase and deferoxamine inhibited or reduced the development of myringosclerosis, whereas the ears treated with copper sulfate plus iron chloride appeared unaffected. Consequently, the finding...
The Annals of otology, rhinology, and laryngology, 1993
Topically applied hydrocortisone was used to develop an animal model for persistent tympanic memb... more Topically applied hydrocortisone was used to develop an animal model for persistent tympanic membrane (TM) perforations. Hydrocortisone suspension was applied on the margins of TM perforations of standardized size in rats once daily for 10 days. The healing patterns of the TMs were mapped weekly and, when the perforations were about to close, daily. After 50 days, all hydrocortisone-treated perforations were open, whereas the controls closed within 9 to 12 days. At 3 months, when one third of the perforations still were open, the TMs were studied by otomicroscopy and light microscopy. All TMs were thickened and covered by keratin and wax. The thickened epidermal layer at the border of the TM perforations that remained open also draped the surface of the perforation facing the middle ear cavity. The thickened connective tissue layer contained abundant fibroblasts with their axes of length oriented at random. Both application of 1.4% hyaluronan and wounding of the perforation border e...
ORL; journal for oto-rhino-laryngology and its related specialties, 1994
Heparin, in concentrations of 250, 2,500 and 25,000 IU, was applied topically to the edge of tymp... more Heparin, in concentrations of 250, 2,500 and 25,000 IU, was applied topically to the edge of tympanic membrane (TM) perforations, standardized in size, once daily until the perforation had closed. At 2 months, the animals were killed and the TMs subjected to otomicroscopic and light microscopic studies. The day that closure of the TM perforations was complete (median 8 days) was the same for the various heparin groups as for the sterile water-treated controls. However, regarding opacity of the healed TM area, heparin affected the TM in a dose-dependent manner. The TMs that had been subjected to the highest concentration of heparin were the most transparent and showed the least sclerosis. When compared for thickness, the TMs treated with the higher concentration of heparin were considerably thinner than those treated with the lower concentration. The sterile water-treated controls were all thicker than the heparin-treated TMs. It is inferred that glycosaminoglycan heparin improves th...
Pharmacologic labyrinthectomy has become an alternative to surgery for treatment of severe Ménièr... more Pharmacologic labyrinthectomy has become an alternative to surgery for treatment of severe Ménièr's disease. The use of systemic streptomycin has been replaced by intratympanal instillations of gentamicin that are administered once daily for a limited number of days. Gentamicin provides a high success rate for ablation of vertigo without causing any unnecessary negative effects on hearing. Future development of more selective vestibulotoxic chemicals could mean that pharmacologic labyrinthectomy will become a simple and ultimate treatment for disabling Ménière's disease.
The Annals of otology, rhinology, and laryngology, 1995
The purpose of this study was to elucidate possible relationships between the oxygen concentratio... more The purpose of this study was to elucidate possible relationships between the oxygen concentration of the middle ear cavity and the development of myringosclerosis. Three groups of rats with myringotomized tympanic membranes were exposed to different oxygen concentrations of 10%, 15%, and 40%, respectively, for 1 week. A fourth group was kept in ambient air. Two other groups of rats with myringotomized and intubated tympanic membranes were exposed to oxygen concentrations of 10% and 40%, respectively, for the same period of time. Otomicroscopically, all hyperoxic animals had more numerous myringosclerotic lesions compared with the ambient air group, and also displayed a pronounced hyperplasia of the keratinizing epithelium around the perforation border. By contrast, the hypoxic animals showed less pronounced myringosclerotic lesions or even completely lacked them. It is inferred that an increased oxygen concentration in the middle ear cavity will increase the likelihood of myringosc...
International journal of pediatric otorhinolaryngology, 1984
Already within 24 h, splitting of the soft palate in rats caused production of effusion in the at... more Already within 24 h, splitting of the soft palate in rats caused production of effusion in the attic space. During the next couple of days the effusion material filled the meso- and hypotympanon. The production of a serous fluid in the attic space appeared concomitant with an elevated histamine content in the middle ear cavity, irrespective of whether the ears were ventilated or not. In the artificially ventilated middle ears no effusion appeared in the meso- and hypotympanon and the hypotympanal mucosal lining remained normal. The serous effusion filling the middle ear cavities with the intact tympanic membranes was replaced at about 7 days by a purulent effusion material containing mainly Gram-negative enteric rods. Thus it seems that a serous otitis media and a purulent otitis media occur in a continuum. The change to a purulent infection could be prevented by artificial ventilation, but as soon as the myringotomies were healed or the tympanostomy tubes got clogged a flocculent, ...
The aim of the present study was to experimentally provoke well-defined serous and purulent effus... more The aim of the present study was to experimentally provoke well-defined serous and purulent effusion materials and to analyze the fluid using cytological and immunochemical techniques. Using these parameters an attempt was made to find a marker(s) for the degree of inflammation, duration of the disease and possible sequelae.
The method of auditory evoked brainstem responses (AEBR) was applied on an animal model with two ... more The method of auditory evoked brainstem responses (AEBR) was applied on an animal model with two types of well defined middle ear effusions--serous otitis media (SOM) and purulent otitis media (POM). The animals with SOM exhibited fairly normal interpeak latencies but a considerably increased auditory threshold. In contrast, POM mainly affected the latencies of the brainstem evoked potential but also caused a slight increase of the auditory threshold. The results indicate that SOM chiefly causes a conductive hearing loss, while POM also affects the neural circuit.
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Papers by Sten Hellström