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Biomedical subjects

L Bergstrom

Publications and source records attributed to L Bergstrom.

At least 19 recordsLinked to original sources
PubMed1995

Tandem binding of six OmpR proteins to the ompF upstream regulatory sequence of Escherichia coli.

OmpR is a transcription factor in Escherichia coli whose function is modulated by phosphorylation in the presence of phosphorylated EnvZ, a transmembrane protein histidine kinase involved in osmosensing. Using a protein S-OmpR hybrid protein, we demonstrated that six OmpR molecules bind tandemly to the -100 to -39 sequence of ompF. This sequence consists of three 20-base pair units: F1, F2, and F3, each of which is bound by two OmpR proteins. Polymerase chain reaction selection of nine randomized base pairs within the F1 sequence revealed highly conserved C residues spaced 10 base pairs apart. Further mutational analysis of conserved bases indicated that two OmpR molecules bind tandemly to two direct repeats. Mobility shift assays showed that cooperative interactions play a role in enhancing binding of OmpR to lower affinity F2 and F3 sites. Activation and repression of ompF expression are thus regulated by a total of eight OmpR molecules, including two molecules that bind to a distal site (-380 to -361).

Bacterial Outer Membrane Proteins↗
PubMed1992

"You'll feel me touching you, sweetie": vaginal examinations during the second stage of labor.

Videotapes of women during the second stage of labor and their caregivers were examined in this descriptive study to determine how caregivers performed sterile vaginal examinations. Conversational analysis techniques were used to analyze the data. Results showed that the examinations were performed in a ritualistic manner by all caregivers, and the way the ritual was enacted repeatedly demonstrated the power of the caregivers over the women. The most common reason for performing the procedure, to help the woman push better, seems to be specific to the second stage of labor and is not described in the literature. The authors offer suggestions for better use of the examination, and recommend that it be performed far less frequently than is common.

Adolescent↗
PubMed1984

Recurrent retropharyngeal abscess.

An infant had a case of recurrent retropharyngeal abscess. This clinical entity usually follows an upper respiratory tract infection with involvement of the retropharyngeal lymph nodes. Management includes incision and drainage as the patient's clinical status dictates and may require long-term intravenous antibiotic therapy. A biopsy of the abscess wall, assessment of the patient's immunocompetence, and a search for contributory anatomic defects may be useful. A computed tomographic scan is a valuable technique for diagnosis and follow-up.

Abscess↗
PubMed1984

Posterior choanal atresia: a syndromal disorder.

Posterior choanal atresia has a significant incidence of associated defects. Recently a constellation of defects, bearing the acronym of CHARGE, has been described. Its entities are (ocular) Coloboma, Heart defects, Atresia choanae, Retarded growth and development, Genital hypoplasia and Ear anomalies or hearing loss. Some of these have been previously noted. There are 26 patients in this series, none having the entire CHARGE association, but 7 had several; 3 of the 7 had bilateral choanal atresia. One other patient had a chromosomal defect with an associated heart defect. Two patients had cardiac and other visceral defects. Seven had base of skull abnormalities, 3 of whom had elements of CHARGE, and 9 had congenital hearing loss. Five were normal. CT scan suggests a growth disturbance of the basicranium in some of the patients.

Abnormalities, Multiple↗
PubMed1984

Teratomas of the head and neck in childhood.

Teratomas are tumors consisting of tissue arising from all three embryonic germ layers. Their occurrence in the head and neck region is rare. Three patients with this lesion are presented. Although exhibiting progressive uncoordinated growth, histologic evidence of malignancy in the head and neck form of this tumor is distinctly uncommon. Mortality associated with teratomas is most often secondary to respiratory compromise. Complete surgical extirpation is the treatment of choice to lower mortality and recurrences. The use of fine needle aspiration in the management of neck masses in children is discussed.

Biopsy, Needle↗
PubMed1983

Concurrent measurement of substance P and serotonin in spinal superfusates: failure of capsaicin and p-chloroamphetamine to co-release.

This study examined the efflux of endogenous serotonin and substance P-like immunoreactive material into in vivo superfusates of the rat spinal cord under quiescent conditions and during the addition of either capsaicin or p-chloroamphetamine to the superfusate. Using a method which permitted concurrent measurement of serotonin and substance P-like immunoreactive material in the same sample of superfusate, it was found that capsaicin increased the efflux of substance P-like immunoreactive material from the spinal cord but did not alter the efflux of serotonin. Conversely, the addition of p-chloroamphetamine caused the efflux of serotonin from the spinal cord to increase, but did not affect the efflux of substance P-like immunoreactive material.

Amphetamines↗
PubMed1983

Early childhood education: a means to earlier diagnosis of hearing impairment in the multihandicapped.

Detection of congenital or infantile hearing loss is often delayed in otherwise normal children, but even greater delays occur in the multihandicapped. Neonatal hearing screening and high risk register techniques have not had universal acceptance. A collaborative project between medical school otology and audiology personnel and a school for multihandicapped children under the age of 3 years in the Department of Special Education in another university has significantly reduced detection time and provided speech, language and other remedial therapy while otologic diagnosis and educational functional assessment proceed. The investigators and staff are bilingual. Parents learn to observe and work with their own child at the school and in the home.

Child, Preschool↗
PubMed1983

Hearing loss in pediatric renal patients.

Modern techniques of prolonging life and useful function for endstage renal patients have been accompanied by a variety of new clinical and pathological manifestations, among which are inner ear problems. Of 151 pediatric renal patients followed prospectively 47% had hearing loss, which closely approximates that found in renal patients of all ages. However, only 5.3% of pediatric-age patients, as compared with 15% of all age groups, have hearing loss of unknown etiology. Certain types of hearing loss, for example, those due to acoustic trauma and Ménière's, were not found in the pediatric-age group, while ototoxic, congenital and genetic hearing losses were more common in young persons than in the overall group. Management includes assessment of hearing and vestibular function prior to and at intervals during the administration of ototoxics, monitoring of blood levels, careful attention to otological symptoms and observing the principles of hearing conservation.

Adolescent↗
PubMed1982

Laryngeal papillomatosis: recurrence after 33-year remission.

After repeated laryngeal papilloma excisions, a 4-year-old Caucasian male became symptom-free. Benign squamous papilloma recurred in the larynx and trachea at age 37 after a gunshot wound, prolonged nasogastric intubation, several laparotomies, endotracheal anesthesias, and massive weight loss. This case and others in the literature suggest that current therapy produces prolonged remission, not "cure." Its course reinforces accumulating evidence for the existence of human papilloma viruses (HPV) whose DNA apparently becomes incorporated into host laryngeal cell DNA, supporting an hypothesis that HPV remains in normal-appearing epithelium adjacent to papilloma. Like herpes zoster varicella virus, HPV may lie dormant until reactivated by host immunosuppression, trauma, malnutrition or sepsis, features also present in the patient described. Repeated intubation probably injured and destroyed cells, releasing viral material. Papilloma patients in remission probably should be warned of factors, including intubation for elective surgery, which could induce recurrence.

Adult↗
PubMed1981

Fragile bones and fragile ears.

Conductive, sensorineural and mixed hearing loss occur in osteogenesis imperfecta in autosomal dominant inheritance pattern. Hearing loss is generally due to the middle and inner ear pathology of osteogenesis imperfecta and only occasionally to the coincidental association of otosclerosis and osteogenesis imperfecta. Two lesions cause the conductive hearing loss of osteogenesis imperfecta: (1) functional ossicular discontinuity due either to stapes superstructure fracture or fibrous replacement, or (2) thick, crumbly, lightly fixed stapes footplate. Cochlear hair cell loss, stria vascularis atrophy and calcification, tectorial membrane distortion and perilymph hemorrhage are autopsy findings that could account for sensorineural hearing loss, which occurs in a surprisingly high percentage of osteogenesis imperfecta patients. Hearing loss occurs earlier in osteogenesis imperfecta than in otosclerosis. Distinctive acoustic impedance and X-ray abnormalities occur in osteogenesis imperfecta. Other otologic findings may include lopped pinna, notching of the helix of the pinna, rosy flush of the medial wall of the middle ear and vestibular abnormalities.

Adult↗
PubMed1980

Renal disease. Its pathology, treatment, and effects on the ear.

Twenty-six hemodialysis and renal transplant patients were studied for the effects of age, duration of kidney failure, amounts and types of treatment, disturbed calcium metabolism, and vascular disease on clinical and pathologic inner ear manifestations. Three subgroups of patients were compared with each other: (1) those having hearing loss of unknown etiology, (2) those having strial deposits, and (3) those having neither. Severity of treatment was not necessarily predictive for severity of inner ear disease. Within each subgroup there was wide variability and almost complete overlap for the factors studied when the three groups were compared. Cochlear strial deposits seem to bear little relationship to disturbed calcium meatbolism or to vascular disease, but their size may be related to the presence of hearing loss.

Adolescent↗
PubMed1980

Continuing management of conductive hearing loss during language development.

Recently greater attention has been focussed on the possibility that mild fluctuating or intermittent hearing loss, as seen in one of early childhood's most common illnesses, otitis media, may have long-lasting and sometimes devastating effects on language development and learning. Conductive hearing loss in serous otitis media most affects frequencies below 2000 Hz, and the duration of hearing loss after an acute episode of otitis media may last 6-24 months in up to 30% of affected children. The first principle of management of this problem and congenital conductive hearing loss is detection prior to language delay. Special attention should be given to neurologically handicapped, retarded, learning disabled or physically frail children since their deficient speech and language are often attributed to abnormal neurologic or intellectual status. Treatment includes limited use of vasoactive decongestants; for acute suppurative otitis media antibiotics may be chosen empirically with a high percentage of good results. Other measures include speech and language evaluation, home stimulation language programs and temporary or longterm amplification. The surgeon assesses the patient for potential operability. Surgery to correct a congenital conductive lesion should not be attempted in an only hearing ear.

Acoustic Impedance Tests↗
PubMed1980

Edge enhancement computed tomography scanning in inflammatory lesions of the middle ear.

The high resolution modification of an EMI 5005 scanner was utilized with an edge enhancement technique to study inflammatory lesions of the temporal bone. Bone erosions caused by cholesteatomas can be accurately delineated because of the circumscribed nature of expansion. The soft tissue masses cannot be appreciated by present CT techniques. Erosions of the horizontal semicircular canal and involvement of the sinus tympani are readily visualized by CT scanning. Computed tomography is limited in demonstrating the stapes superstructure and horizontal portion of the facial canal due to the inability to obtain good coronal scans. The remaining ossicles can be demonstrated with equal clarity with pluridirectional tomography.

Bone Resorption↗
PubMed1980

Erythromycin ototoxicity.

Erythromycin is considered one of the safest antibiotics in common use today. In its otolaryngologic use, the authors have found it effective in treating acute suppurative sinusitis and occasionally otitis media, when combined with sulfonamides. There are few complications of erythromycin administration. Probably the least generally acknowledged of these is ototoxicity. There have been three reports of six cases with ototoxic complications from erythromycin, primarily from administration of its intravenous form. The authors present a case study of an 18 year old girl in severe renal failure, who suffered a reversible sensorineural hearing loss from high doses of an oral erythromycin preparation. The clinical manifestations of this case are compared to those previously reported.

Adolescent↗