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Biomedical subjects

G Granström

Publications and source records attributed to G Granström.

At least 55 records · Page 3Linked to original sources
PubMed1993

Bone-anchored reconstruction of the irradiated head and neck cancer patient.

Titanium implants in facial bones for retention of epitheses or dental bridges were used for reconstruction in cancer patients after tumor surgery. Even heavily irradiated bones could integrate the implants and bear the load from the epithesis. No major complications, such as wound infection, fistulation, or osteoradionecrosis, occurred after implant surgery. There was, however, an increased loss of implants with time after irradiation, especially in the orbital region. When hyperbaric oxygen was used as adjunctive treatment, implant losses were reduced.

Adolescent↗
PubMed1993

The bone-anchored hearing aid and bone-anchored epithesis for congenital ear malformations.

Surgery for correction of aural atresia was performed on 156 ears in 111 patients. A comparison was made between plastic surgery for auricular reconstruction and the bone-anchored epithesis. Another comparison was performed between hearing improvement after reconstructive surgery for meatal and middle ear atresia and the bone-anchored hearing aid. It was found that the bone-anchored epithesis is an excellent alternative to plastic reconstructive surgery of the auricle. The bone-anchored hearing aid could be considered as a strong alternative to surgery in patients with meatal and middle ear atresia--especially in patients with advanced malformations. Neither the bone-anchored epithesis nor the bone-anchored hearing aid excludes the patient from reconstructive surgery later in life.

Adolescent↗
PubMed1993

Postimplantation irradiation for head and neck cancer treatment.

Eleven patients who had undergone surgical treatment for head and neck cancer and had titanium implants placed for skin-penetrating prostheses were irradiated postimplantation. The absorbed doses of irradiation to the implant region varied between 50 and 80 Gy. The time interval between implant surgery and irradiation varied from 4 to 60 months. Of 32 fixtures placed, 2 were removed as part of extended tumor surgery and 2 were lost in conjunction with induced chemotherapy. Five of the patients showed skin dehiscences around 9 implants after completed irradiation. Osteoradionecrosis developed in three of the patients after radiotherapy. If irradiation is to be performed in areas where titanium implants have been placed, it is recommended that all prostheses, frameworks, and abutments be removed before irradiation; the fixtures should be allowed to remain intact but should be covered with skin or mucosa.

Adolescent↗
PubMed1993

The effects of hyperbaric oxygenation on bone-titanium implant interface strength with and without preceding irradiation.

This study investigated the influence of a single 15-Gy dose of irradiation on the capacity of titanium screws to integrate in irradiated bone tissue. The biomechanical force necessary to unscrew the titanium implants 8 weeks after placement was 54% lower for implants in irradiated bone tissue compared to implants in nonirradiated bone tissue. Postirradiation use of hyperbaric oxygen treatment at 2.8 ATA (2-hour daily treatments for 21 days) increased the biomechanical force necessary to unscrew the titanium implants by 44% in irradiated bone and by 22% in nonirradiated bone.

Animals↗
PubMed1992

Histochemical analysis of enzymes involved in the formation and metabolism of the nasal septal cartilage.

Formation of the nasal septal cartilage in prenatal and neonatal rats was studied histologically and by histochemistry to determine the manner, degree and participation of the nasal septal cartilage in midface growth and in bone formation of the face. Chondrogenesis of the nasal septal cartilage started at the 13th embryonic day, premaxillary and vomerin bone formation at the 14th embryonic day and endochondral bone formation of the septo-presphenoid area at the 17th embryonic day. After differentiation of the nasal septal cartilage, this cartilage supported ethmoid bone formation by endochondal ossification in the septo-presphenoid area. Nasal septal cartilage showed intense activity of lactate dehydrogenase, NADH2-diaphorase and a moderate activity of acid phosphatase, whereas premaxillary and vomerin bone showed intense activity of alkaline phosphatase. Osteoblasts showed intense activity of alkaline phosphatase, lactate dehydrogenase and NADH2-diaphorase and osteoclasts showed intense activity of acid phosphatase. During the embryonal period growth of the nasal septal cartilage could occur in an ethmoido-rostral direction supported by endochondral ossification and growth in length and height supported by apposition and interstitial growth.

Animals↗
PubMed1992

Influence of allergy, asthma and hypertension on nasal polyposis.

Arterial hypertension was found in 78 of 224 consecutive patients operated for nasal polyposis. An exacerbated degree of hypertension was significant in groups aged above 50 years. In total, 46% of patients whose nasal polyposis lasted for more than 10 years suffered from hypertension. Fifty of 78 patients developed hypertension after nasal polyposis had been established, and the mean duration time from polyposis to hypertension was 11.1 years. Eosinophilic infiltration was found in 88% of nasal polyps. Of the patients with eosinophilic polyps, 34.8% were classified as atopic. The most common allergens were house dust, tree- and grass pollen, mite and acetyl salicylate. Hyposensitization against known allergens reduced necessary polypectomy frequency in 60% of patients. The third most common concurrent disease was asthma (26.1%). Ten cases of the triad: asthma, intolerance to acetyl salicyclic acid and nasal polyps were found, comprising 4.4% of all patients. Fifty percent of these patients also had hypertension. This investigation strengthens earlier studies that hypertension is not an aetiologica factor for nasal polyposis but can develop secondary to nasal obstruction.

Adolescent↗
PubMed1992

Diagnosis of induced cleft palate in rats from defective patterns of differentiation of isoenzymes.

Cleft palate was induced in 420 embryos of Sprague-Dawley rats with a single oral dose of 600 mg/kg beta-aminoproprionitrile (BAPN) on embryonal day 15, 7 hours. The cleft palate was accompanied by a pathological differentiation pattern of various isoenzymes in palatal shelves. These isoenzymes could be detected in amniotic fluid from the 16th to the 20th days of pregnancy when they also had a pathological differentiation pattern. We conclude that teratogenically induced cleft palate in rats is accompanied by a pathological differentiation pattern that can be traced by determination of isoenzymes in the palatal shelves as well as in amniotic fluid.

Abnormalities, Drug-Induced↗
PubMed1992

Titanium implants in irradiated tissue: benefits from hyperbaric oxygen.

Since the introduction of osseointegrated titanium implants for bone-anchored facial and dental prostheses, an increasing number of irradiated patients are being treated with this technique. Although the number of patients who have had titanium implants after irradiation is limited, available statistics point to a tendency of a higher implant loss frequency as compared with nonirradiated patients. This review discusses factors behind deleterious tissue effects and implant failures from irradiation and points to possibilities to improve the surgical outcome with special reference to hyperbaric oxygen therapy.

Animals↗
PubMed1992

Ear deformities in mandibulofacial dysostosis.

Bilateral conductive deafness is common in mandibulofacial dysostosis with or without atresia of the external auditory meatus. This deafness is due to a wide range of deformities of the ossicular chain associated with a characteristic reduction in the size of the middle ear cavity. The inner ear is only occasionally affected. This study describes findings of experimentally induced malformations of the ears in laboratory animals which are compared to the clinical, radiological and surgical findings from 14 patients with mandibulofacial dysostosis (Treacher-Collins syndrome).

Abnormalities, Drug-Induced↗
PubMed1991

Diagnostic value of clinical and bacteriological findings in pertussis.

Clinical and bacteriological findings in the diagnosis of pertussis were evaluated in 300 consecutive patients with parental or the patient's own suspicion of the disease. Serology was used as a reference method. Of the 285 (95%) patients fully sampled, 163 (57%) were diagnosed as having pertussis while the remaining 122 patients constituted the non-pertussis control group. The clinical and epidemiological data were collected at the first visit made on median day seven of illness. In this population of mainly unimmunised children, the highest predictive values were obtained for the physician's diagnosis of pertussis (100%) and for the physician's diagnosis of some other illness (93%). The only clinical symptom with a high predictive value for pertussis was the report of whoops (92%). Among epidemiological data the highest predictive value (90%) was obtained for reported household exposure in unimmunised children more than 1 year of age. Culture of Bordetella pertussis was found to have an overall 50% sensitivity. Isolation of other bacteria had no predictive value in the differential diagnosis of pertussis.

Adolescent↗
PubMed1991

Bordetella pertussis adenylate cyclase activity in nasopharyngeal aspirates for rapid diagnosis of whooping cough in relation to culture and serology.

Adenylate cyclase activity, measured in 201 nasopharyngeal aspirates from patients presenting with own or parental suspicion of whooping cough, was compared to diagnosis made by culture and by serology in the culture negative cases. The median amount of cyclic AMP in samples from culture negative patients (n = 145) was 0.60 pmoles which differed significantly (p less than 0.001) from the median value 3.28 in samples from culture positive patients (n = 56). The median value 0.70 pmoles of cyclic AMP in samples from culture negative patients who were positive by serology (n = 54) did not differ significantly from the value of 0.57 pmoles in samples from serology negative patients (n = 91). With a limit for positive cyclic AMP set at 2 pmoles, 45 samples were positive. The sensitivity of the assay was 66% (37/56) in culture positive patients while the specificity was 93% (85/91) in the serology negative patients. The positive predictive value for the c-AMP test was 82% (37/45) in relation to culture and 87% (39/45) in relation to culture and/or serology. The results confirmed that measurement of adenylate cyclase activity in nasopharyngeal aspirates by an 1-h incubation method can serve as an early and rapid diagnostic method of pertussis infection. The low sensitivity of the c-AMP assay in samples from serology positive but culture negative patients indicates however, that this assay will have to be supplemented by serology for a high diagnostic sensitivity in all cases of pertussis.

Adenylyl Cyclases↗
PubMed1991

Transplantation of facial processes for repair of induced branchial arch syndromes.

A technique has been developed by which facial processes with adequately migrated neural crest tissue can be cultured and transplanted to embryos with induced craniofacial malformations. Culturing was carried out in the anterior eye chambers of adult rats or as whole embryo cultures in glass vials (n = 71). Facial processes transplanted to the anterior eye chamber differentiated to cartilage, bone, and mesenchymal tissues. It was possible to keep the embryos alive in whole tissue culture for up to 24 hours. The addition of epidermal growth factor to the culture medium resulted in accelerated growth of epithelium on the surface of the facial processes. Facial processes were accepted when transplanted to either normal or etretinate treated embryos. Epithelium covered the transplanted facial processes, neural crest tissue was seen in the centre, and capillaries were in close contact to the base of each one.

Abnormalities, Drug-Induced↗
PubMed1991

Enzyme histochemical analysis of craniofacial malformations induced by retinoids.

Craniofacial malformations were induced in 256 embryos from 32 pregnant rats by a single intraperitoneal injection of 10 mg/kg etretinate at 8.5 days gestation. The litters developed several malformations including microtia, low set and dorsally placed outer ears, defective middle ear ossicles, short cochleas, defectively differentiated Meckel's cartilages, micrognathia, rudimentary malar bones, lateral facial clefts, fistulas, and skin tags, all of which tissues are derivatives of the first and second branchial arches. The teratogenically induced syndrome shows similarities to the mandibulofacial dysostosis syndrome in man. The defects were accompanied by a change in the histochemical differentiation and location of various enzymes in the craniofacial tissues.

Abnormalities, Drug-Induced↗
PubMed1990

Ear discharge after insertion of transmyringeal tubes.

The peroperative bacteriology and cytology of the middle ear have been studied in 103 ears in 65 children operated on due to longstanding secretory otitis media. Within one month postoperatively, 12 ears (12%) showed signs of infection with discharge from the tube. Ten out of these 12 ears showed peroperative growth of Hemophilus influenzae, Branhamella catarrhalis, pneumococci or staphylococci in the middle ear effusions, a significant difference compared to ears without postoperative discharge. The peroperative cytological evaluation of the middle ear effusions from 10 out of the 12 patients with postoperative ear discharge showed presence of phagocytes as a sign of infection. It is concluded that pre-existing bacteria in the middle ear effusion of patients with longstanding secretory otitis media might increase the risk of postoperative infection within the first month after insertion of transmyringeal tubes.

Bacteria↗
PubMed1990

DNA hybridization for diagnosis of pertussis.

The aim of the present study was to evaluate a mixed phase DNA hybridization assay for detection of Bordetella pertussis and Bordetella parapertussis in nasopharyngeal aspirates from patients with suspected pertussis. Among 179 consecutive patients with own or parental suspicion of pertussis, the diagnosis was confirmed in 103 patients by serology and in 52/103 (50%) cases also by culture. The remaining 76 patients served as nonpertussis controls. Direct hybridization was positive in 38% samples with serology as reference method, a non-significant difference to the 50% sensitivity for culture. Preculture of samples on membranes for 24, 48 and 72 h gave a significantly higher sensitivity only with 72 h preculture, 69% vs 50% (P = 0.007). The 72h preculture gave, however, also a significant decrease of specificity, 87% vs 100% for routine culture (P = 0.001) and is not a more rapid diagnostic method. The result shows that rapid diagnosis by DNA hybridization can be achieved in a large proportion of pertussis cases. The presence of smaller numbers of bacteria in samples only positive after preculture indicate that DNA hybridization could be a highly sensitive diagnostic method with further development of more rapid amplification systems.

Bordetella↗
PubMed1990

Malformations of the maxillofacial region induced by retinoids in an experimental system.

Treatment of pregnant Sprague-Dawley rats with etretinate or retinoic acid on pregnancy Day 8.5-9.0 resulted in craniofacial malformations in 100% of the embryos. A morphological investigation of the maxillofacial malformations was undertaken. Retinoid-exposed embryos showed a reduced skull base, flattened and elongated occiput and micrognathia. The malar bones were reduced or missing. Meckel's cartilage was delayed in differentiation as was the mandibular bone. The fusion between different facial processes was disturbed which resulted in facial and palatal clefts. Disturbance of the development of the hypophysis was combined with persisting Rathke's pouch. Aplasia of incisor and molar tooth buds was seen as was aplasia of salivary gland ducts. The facial artery was hyperplastic.

Abnormalities, Drug-Induced↗