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Biomedical subjects

G Granström

Publications and source records attributed to G Granström.

At least 37 records · Page 2Linked to original sources
PubMed1999

First and second branchial arch syndrome: aspects on the embryogenesis, elucidations, and rehabilitation using the osseointegration concept.

BACKGROUND: The osseointegration concept has dramatically changed the possibility of rehabilitating patients with craniofacial defects due to branchial arch syndromes. PURPOSE: This article describes some problems related to the investigative routines and rehabilitation of individuals with malformations of the first and second branchial arches of the craniofacial region. Animal model systems have increased the knowledge of basic embryonic processes that can explain the extent of the malformations. Though most clinical first and second branchial arch syndromes are likely to be caused by sporadic mutations, inherited syndromes occur and also teratogenically induced syndromes are known. Prenatal diagnosis ruling out heredity and exogenous influence seems possible in the future. The possibility of preventing and alleviating fulminant syndromes prenatally also could be conceivable in the future. PATIENTS AND METHODS: The rehabilitation process starts early after birth and should involve a team of specialists including clinical geneticists, pediatricians, audiologists, plastic surgeons, maxillofacial surgeons, otosurgeons, anaplastologists, speech pathologists, pedodontists, and orthodontists. With the development of the osseointegration concept in which craniofacial prostheses and hearing aids can be adapted on implants anchored in the craniofacial skeleton, a new field in the rehabilitation of these malformations has opened. RESULTS: Important aspects in the use of the osseointegration concept include determination of the lowest age for implant surgery, accessibility of adequate bone for implants, the growth of the craniofacial skeleton during childhood, and the possibility for the patient and his or her parents to care for the skin penetration. Adverse tissue reactions, durability of craniofacial prostheses, and the possibility of unknown adverse reactions to metal implants in the body over a long time are other aspects of concern. CONCLUSIONS: Patients with branchial arch syndromes benefit from a well-planned multidisciplinary rehabilitation process in which osseointegrated bone-anchored hearing aids and bone-anchored ear prostheses can be useful tools.

Adolescent↗
PubMed1999

Guided tissue generation in the temporal bone.

Ten patients with malformations of the temporal bones were submitted to installation of implants for anchorage of bone-anchored auricular epistheses or bone-anchored hearing aids. Due to lack of bone in the temporal region, expanded polytetrafluoroethylene membranes were used to aid bone generation, each patient serving as his or her own control. It was found that bone formation around the flange fixtures covered with membranes increased significantly compared to the uncovered fixtures. It is concluded that the use of barrier membranes is one way to support bone generation in temporal bones lacking sufficient bone for implant-related surgery.

Bone Regeneration↗
PubMed1998

Stability measurements of craniofacial implants by means of resonance frequency analysis. A clinical pilot study.

Nineteen patients previously treated with 52 implants for anchorage of craniofacial prostheses were subjected to implant stability measurements by means of resonance frequency analysis (RFA), six months to 15 years after implant placement. The resonance frequency (RF) of a transducer attached to the implant abutment was measured by using a frequency response analyser, a personal computer (PC) and dedicated software. Statistically significant higher RF values were seen for implants in the temporal bone as compared to implants in the nose and periorbital regions. There was a positive correlation with time since implant placement for the period from six months up to seven years. It was concluded that the preliminary results suggest that implant stability increases with time and that implants in temporal bone are more stable than implants in the bone in the nose and periorbital regions, probably reflecting differences in bone density.

Adult↗
PubMed1997

Differential expression of tissue-specific adhesion molecules on human circulating antibody-forming cells after systemic, enteric, and nasal immunizations. A molecular basis for the compartmentalization of effector B cell responses.

Expression of the adhesion molecules CD44, L-selectin (CD62L), and integrin alpha 4 beta 7 by antibody-secreting cells (ASC) was examined in human volunteers after oral, rectal, intranasal, or systemic immunization with cholera toxin B subunit. Almost all blood ASC, irrespective of immunization route, isotype (IgG and IgA), and immunogen, expressed CD44. On the other hand, marked differences were observed between systemically and intestinally induced ASC with respect to expression of integrin alpha 4 beta 7 and L-selectin, adhesion molecules conferring tissue specificity for mucosal tissues and peripheral lymph nodes, respectively. Thus, most ASC induced at systemic sites expressed L-selectin, whereas only a smaller proportion of ASC expressed alpha 4 beta 7. In contrast, virtually all IgA- and even IgG-ASC detected after peroral and rectal immunizations expressed alpha 4 beta 7, with only a minor fraction of these cells expressing L-selectin. Circulating ASC induced by intranasal immunization displayed a more promiscuous pattern of adhesion molecules, with a large majority of ASC coexpressing L-selectin and alpha 4 beta 7. These results demonstrate that circulating ASC induced by mucosal and systemic immunization express different sets of adhesion molecules. Furthermore, these findings provide for the first time evidence for differential expression of adhesion molecules on circulating ASC originating from different mucosal sites. Collectively, these results may explain the anatomical division of mucosal and systemic immune responses in humans as well as the compartmentalization of mucosal immune responses initiated in the upper vs. the lower aerodigestive tract.

Administration, Inhalation↗
PubMed1997

Effects of vitamin B6 on beta-aminoproprionitrile-induced palatal cleft formation in the rat.

OBJECTIVE: This study was conducted to evaluate the effects of beta-aminoproprionitrile and vitamin B6 on palatal clefting. METHOD: In four groups of pregnant Sprague-Dawley rats, beta-aminoproprionitrile (BAPN; 600 mg/kg b.w.) was given by gavage on embryonal day 15, 7 hours to induce palatal clefts. Vitamin B6 (10 mg/kg b.w., IM) was given twice on embryonal day 14, 7 hours and on day 15, 7 hours. The possibility that the food's content of vitamin B6 affected the results was also tested. Palatal cleft formation was divided into four different grades, ranging from no cleft formation to total cleft formation. RESULTS/CONCLUSION: It was found that BAPN induces cleft palate in rat fetuses and that this defect can be prevented both in number and severity by administration of vitamin B6 before and simultaneously with BAPN.

Administration, Oral↗
PubMed1997

Clinical appearance of spontaneous and induced first and second branchial arch syndromes.

The clinical appearance was investigated of 29 patients with mandibulofacial dysostosis, 26 with hemifacial microsomia, and seven with thalidomide-induced malformations affecting derivatives of the first and second branchial arches. Malformations of the external ear, ear canal, middle ear, zygoma, maxilla, mandible, and lower eye lid were prominent features of the syndromes. Facial nerve and 6th cranial nerve paralysis as well as anophthalmia or microphthalmia were seen only in patients with hemifacial microsomia and in the thalidomide-induced syndrome. We compared the clinical results with those in an animal model in which an induced first and second branchial arch syndrome depends on disturbed migration of neural crest cell during early embryogenesis. The critical time for a similar process in humans would be between the 20th and 29th days of pregnancy.

Adult↗
PubMed1997

The bone-anchored hearing aid (BAHA) in children with auricular malformations.

A retrospective study was undertaken to evaluate the outcome of the use of the bone-anchored hearing aid (BAHA) in children. All patients included in the study had bilateral auricular malformations. Previous alternatives had been conventional hearing aids or surgical middle ear reconstruction. Thirty-seven patients under 16 years of age were studied. The most common syndrome in the group was Treacher Collins. Sixteen of the patients had earlier middle ear reconstruction, the results of which did not produce social hearing. Of 40 inserted fixtures to anchor the BAHA, three were lost during the follow-up period because of failed osseointegration. Skin reactions were graded according to a clinical scoring system and were determined to be comparable in number and severity to those of an adult population. All patients in the study considered the BAHA to be superior to earlier bone-conduction devices. It is concluded that the BAHA is an excellent alternative to bone-conduction devices in children with auricular malformations. Middle ear surgery can be postponed until adulthood or abandoned, especially in syndromic patients in whom it is known to be difficult and unpredictable.

Adolescent↗
PubMed1997

Cell proliferative modulation of MCG 101 sarcoma from mice exposed to hyperbaric oxygenation.

Tumor cell kinetics were studied in C57 Bl/J mice with a transplantable sarcoma, MCG 101, exposed to hyperbaric oxygen (HBO2), 2.8 atm abs, 2 hours daily for 9 days or until spontaneous death. The isoenzymatic pattern of lactate dehydrogenase (LDH) confirmed that there was a significant shift toward aerobic metabolism in tumor tissue as well as in the liver and skeletal muscle. Recruitment of cells from the G0G1 state into DNA synthesis was associated with an increased mobilization of substrates for polyamine synthesis in terms of an elevated ornithine decarboxylase (ODC) activity. However, cell cycle turnover in terms of bivariate flow cytometric analysis after bromodeoxyuridine (BrdUrd) injection, final tumor weight, and survival time were not changed compared with the controls. Tumor cell metabolism demonstrated evidence of an unchanged net energy utilization, in that activities (V(max) of phosphofructokinase (PFK) and LDH were not significantly changed. When the tumor-bearing animals were exposed to advanced HBO2 pressure (3.7 atm abs) for 3 h as a single dose, the DNA distribution and growth rate were not changed immediately. However, 3.5 h later we observed a DNA pattern similar to that after repeated HBO2 treatments, 2.8 atm abs, concomitant with a preponderance of cells in the late S-phase, which is consistent with a block at the entry of G2M. We conclude that MCG 101 sarcoma recovers from HBO2 exposure by an accumulation of cells in the S-phase without significant changes of net tumor growth. This may have relevance to clinical radiocurability.

Animals↗
PubMed1995

One-stage procedure to establish osseointegration: a zero to five years follow-up report.

A cohort of 214 patients, who were operated on to insert implants in the mastoid process for the retention of bone-anchored hearing aids and auricular prostheses, was follow-up over a five-year period. About half the group were operated on using the conventional two-stage procedure allowing three to four months for osseointegration. In the second group (one-stage group) the skin penetrating coupling was connected at the time of the implant insertion. The success rate for stable implants was found to be the same in both groups. In the one-stage group four out of 161 implants inserted were lost and in the two-stage group three out of 120. The cumulative success rate was also found to be the same. A 'worst case' table where patients lost to follow-up, patients who died during the study period, and patients who for some reason left the study is also included. The importance of this 'worst case' scenario when follow-up data are presented is discussed.

Adolescent↗
PubMed1995

Induction of compartmentalized B-cell responses in human tonsils.

The capacity of tonsillar and nasal mucosal lymphoid tissues to serve as induction sites of local and/or distant B-cell responses in humans has been examined. The frequencies of vaccine-specific antibody-secreting cells (ASC) in cell suspensions from palatine tonsils (PT) and adenoids were determined after local (intra-tonsillar [i.t.]) and regional (intranasal [i.n.]) immunizations as well as peroral and parenteral immunizations with cholera and tetanus toxoids. While peroral and parenteral immunizations evoked negligible ASC responses in PT, i.t. vaccination induced a substantial ASC response which consisted of immunoglobulin G (IgG) and IgA ASC. Responses were highly restricted to immunized tonsils. Primary immunization in one PT followed by a second immunization of both PT evoked a larger ASC response in the primed tonsil. The latter ASC response was associated with higher frequencies of ASC precursors in primed tonsils. Furthermore, two i.n. immunizations induced only modest ASC responses in PT, although such immunizations evoked high ASC responses in adenoids. However, both i.t. and i.n. routes of immunization induced specific peripheral blood ASC responses, suggesting that a fraction of B cells activated in tonsils or in nasal mucosa may enter the circulation and disseminate to distant organs. These blood ASC responses preceded increases in both IgA and IgG antibody titers in nasal washes and serum samples. However, vaccine-specific ASC were not detected in duodenal cell suspensions from volunteers who had received i.t. or i.n. immunizations. Collectively, these results indicate that tonsils can serve as expression sites of locally induced antibody responses and support the development of immunological memory. Furthermore, tonsils may serve as powerful inductive sites for immune responses expressed in the upper aerodigestive tract.

Adenoids↗
PubMed1995

Imprints from the oropharyngeal mucosa: a novel method for studies of cell-kinetics and spatial relations between leukocytes, epithelial cells and bacteria in the secretion on the surface of the mucosa.

Cell-kinetics and spatial relations between the cellular elements in the secretion on the mucosal surfaces of the oral cavity and the pharynx were studied with a new imprint technique whereby pieces of foam-plastic are pressed against the mucosal surfaces and then immediately against a glass slide. For visualisation of leukocytes, epithelial cells and bacteria, imprints were stained according to May Grünewald-Giemsa and with acridine orange. For visualisation and discrimination between T and B-cells, slides were stained with immunohistochemical technique using anti-CD-3 and anti-CD-19, respectively, as antibodies. Imprints were also prepared for scanning electron microscopy (SEM). The results show that there are large numbers of morphologically intact cells in the secretions and that there are statistically significant differences between the different mucosal areas as regards numbers, types and spatial relations between the cellular elements in the surface secretions. Rather great inter- and intra-individual differences in cellular composition were observed, indicating a dynamic system. This was further documented by observation of a dominance of polymorphonuclear leukocytes on the tonsillar surface, in contrast to the dominance of mononuclear leukocytes in secretion from the mesopharynx. We consider that this new imprint method is reliable and gives representative samples from the surface secretion. The results clearly show the need for further studies concerning the physiological role of the cellular elements in the surface secretion of the oral cavity and mesopharynx.

Bacteria↗
PubMed1994

Effect of erythromycin treatment on antibody responses in pertussis.

The effect of erythromycin treatment on antibody responses to Bordetella pertussis filamentous haemagglutinin (FHA) and pertussis toxin (PT) was investigated in convalescent blood samples from 105 children with pertussis. Erythromycin had been given to 59 children, median age 3.2 years (range 0.3-9.9) on median day 7 (range 11-14) after onset of disease while the remaining 46 children, age 3.45 (0.6-8.1) were untreated. No significant differences in IgG antibody concentration were noted to FHA by ELISA and to PT, neither by NT nor by ELISA, but a tendency towards lower median titers was seen to both antigens and by both type of assays in the erythromycin-treated group. Similarly, early erythromycin treatment i.e. within 7 days of onset of symptoms, did not influence significantly of the development of the antibody responses but tended to lead to lower titer levels. A significant response to PT and FHA was found in about 90% of blood samples, irrespective of treatment. All 56 children with culture-confirmed B. pertussis infection had a significant response to PT. The study has thus shown a slight but not significant effect of erythromycin treatment on antibody responses in pertussis.

Adhesins, Bacterial↗
PubMed1994

Long-term follow-up with the bone-anchored hearing aid: a review of the first 100 patients between 1977 and 1985.

Skin-penetrating implants have been used since 1977 for retention of Bone Anchored Hearing Aids, or BAHA. This paper analyzes the stability of the implants and the frequency of skin reactions in the first one hundred consecutive patients operated upon at Sahlgrens Hospital, Göteborg. The follow-up time varied between 8 and 16 years. Ninety percent of the implants were found to be stable. Five percent were explanted due to direct trauma. Another five percent lost integration but often after many years in use. Adverse skin reactions were seen, but 79% of the patients had no or one single episode of soft tissue reaction. A percutaneous coupling in the mastoid process will give rise to only minor clinical problems and could be considered as a simple, predictable and safe device.

Adult↗
PubMed1993

Serological correlates in whooping cough.

Antibody concentrations to three Bordetella pertussis antigens in 94 predisease samples from women who, within a median of 220 days, developed culture-confirmed whooping cough were compared to antibodies in samples from matched controls. The median IgG antibody levels were significantly lower to all three antigens, pertussis toxin, filamentous haemagglutinin and lipopolysaccharide, in the predisease samples of cases as compared to non-cases (p values ranging from 0.0001 to 0.01). A significant difference in antibody distribution was, however, found only to pertussis toxin, measured either by ELISA or by a neutralization test (p values of 0.0004 and 0.007, respectively). The results could be interpreted as meaning that antibodies to the different antigens all participate in protection against disease but that antibodies to pertussis toxin play a major role.

Adhesins, Bacterial↗
PubMed1993

High frequency of spontaneous interferon-gamma-producing cells in human tonsils: role of local accessory cells and soluble factors.

The frequency of mononuclear cells (MNC) spontaneously secreting interferon-gamma (IFN-gamma) has been examined in freshly isolated cell suspensions from human palatine tonsils. Two-site reverse enzyme-linked immunospot (ELISPOT) analyses, involving short term (20 h) incubation of MNC in the absence of any added exogenous stimulus, revealed that tonsillar MNC suspensions contain exceptionally large numbers of cells secreting IFN-gamma. No significant differences were observed when comparing the frequency of IFN-gamma-producing cells between cell suspensions obtained from hyperplastic and tonsillitis specimens. Cell-sorting experiments disclosed that spontaneous tonsillar IFN-gamma production was essentially contributed by CD4+ T cells, and required the presence of accessory cells and/or soluble factors to be detected. Thus, depletion of plastic adherent cells or monocytes from the tonsillar MNC suspensions resulted in reduced numbers of detectable IFN-gamma-secreting cells. Addition of very small numbers of autologous monocytes restored spontaneous IFN-gamma production in tonsillar MNC cultures depleted of monocytes. Neutralization of endogenous IL-1 beta and IL-2, as well as blocking of the IL-2 receptor, also decreased IFN-gamma production from unfractionated tonsillar cells. Addition of exogenous IL-1 beta restored IFN-gamma production in cultures of tonsillar MNC depleted of plastic adherent cells. Furthermore, IL-1 beta synergized with IL-2 by tonsillar MNC depleted of plastic adherent cells. Furthermore, IL-1 beta synergized with IL-2 by increasing intracellular as well as cell-free levels of IFN-gamma in cultures of unfractionated tonsillar MNC. This study further establishes that the tonsils are highly active immunological organs containing large numbers of T cells spontaneously producing IFN-gamma whose detection is contingent upon the presence of functional accessory cells. It also demonstrates that concomitant production of IL-1 beta and IL-2 occurs in tonsils and is necessary to maintain ongoing synthesis and extracellular accumulation of IFN-gamma in these organs.

Adolescent↗