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Biomedical subjects

D Nir

Publications and source records attributed to D Nir.

10 recordsLinked to original sources
PubMed1999

Saccharomyces cerevisiae cells harboring the gene encoding sarcotoxin IA secrete a peptide that is toxic to plant pathogenic bacteria.

Sarcotoxin IA is a cecropin-type antibacterial protein produced by the flesh fly, Sarcophaga peregrina. Similar to other bactericidal small proteins produced by insects, sarcotoxin IA is released into the hemolymph of larvae and nymphs upon mechanical injury or bacterial infection. The gene (sarco) that encodes this toxin was introduced into Saccharomyces cerevisiae yeast cells and was expressed under a constitutive yeast promoter. The transformed yeast cells were grown in a liquid medium, and a peptide with a similar molecular size to that of the mature sarcotoxin IA was detected in the medium by Western blot analysis. The secreted sarcotoxin-like peptide (SLP) had a potent cytotoxic effect against several bacteria, including plant pathogenic bacteria, similar to the toxic effects of the authentic sarcotoxin IA. Erwinia carotovora was more susceptible to the toxic medium than Pseudomonas solanacearum and Pseudomonas syringae pv. lachrymans. Thus, yeast may be used in the production of such proteins for employment against various bacterial pathogens.

Animals↗
PubMed1997

More about pain in the neck: thyroid cartilage and mastoid process syndromes.

Eight patients with cervical pain were examined. The only positive finding was an impressive tenderness over the thyroid cartilage (in seven patients) or over the area of the insertion of the sternocleidomastoid muscle to the mastoid process (in one patient). The diagnosis of thyroid cartilage syndrome and mastoid process syndrome were suggested and the patients were treated with oral and topical non-steroidal anti-inflammatory drugs (NSAIDs) which reduced the symptoms. These syndromes are rare. The thyroid cartilage syndrome has been previously reported only once in the literature and this is the first report on the mastoid process syndrome. These syndromes, although rare, should be included in the list of causes for cervical pain and better recognition of the syndromes will save patients from undergoing unnecessary investigation and inappropriate treatment.

Adolescent↗
PubMed1993

Eustachian tube function during pregnancy.

The upper respiratory mucosa has been reported to react to sex hormones in both physiological and pathological conditions. The present study was specifically aimed to determine the influence of high levels of oestrogen on Eustachian tube function. Fifty-three healthy, pregnant women were prospectively evaluated for Eustachian tube function during pregnancy. Eustachian tube function was found to be highly variable in different women, and in the same woman at different stages of pregnancy. We did not find a specific trend in Eustachian tube function with increasing oestrogen levels as encountered during pregnancy.

Ear, Middle↗
PubMed1992

[An electromechanical model of the middle ear].

A dynamic model of the middle ear and mastoid system was designed in order to evaluate basic principles in tympanometry. The model allows controlled simulation of the exact changes in the ear drum's mass and in intratympanic volume and pressure. The contribution of each of these factors to acoustic impedance was measured. We found that the volume values of static, acoustic compliance were equal to the volume of air in a closed cell. There was good correlation between direct measurement of air pressure in the model cell and indirect pressure measurement by tympanometry. We also demonstrated a difference between mechanical displacement of the drum and its displacement by negative pressure. This demonstration of tympanometry using a middle-ear compatible model enables us to understand its principles and helps in the education of students.

Acoustic Impedance Tests↗
PubMed1991

Effect of estrogen on eustachian tube performance.

Changing levels of sex hormones have been previously associated with clinical symptoms due to alterations of the respiratory mucosa. Aural manifestations, however, have not yet been studied in this regard. Eustachian tube swallow test and blood levels of estrogen were evaluated daily in 25 women undergoing induction of ovulation. Most women showed a near stable eustachian tube performance over a wide range of estrogen levels, particularly in the physiologic range. However, there is a moderate decrease in eustachian tube function with increasing estrogen levels in some women, manifested mainly at levels beyond that of the normal menstrual cycle.

Acoustic Impedance Tests↗
PubMed1990

Malignant external otitis in an infant.

Ten cases of malignant external otitis in children have been reported hitherto. These are reviewe, and an eleventh case, a three-month-old infant associated with genetic granulocytopenia, is presented. On the grounds of the reported paediatric cases, the erudition in childhood is compared with the more common form in the adult, and is found to be much less linked with diabetes mellitus and to have a far better prognosis, with practically no mortality.

Agranulocytosis↗
PubMed1983

A new method of measuring bone density in the lower tibia of normal and postinjury limbs. A quantitative and comparative study.

In osteoporosis, a pathologic state of diminution of bone mass, radiography is the most widely used diagnostic method, but it is only descriptive and mainly depicts changes in the compacta. Based on the Compton photon-scattering phenomenon, a noninvasive yet quantitative measuring method for analyzing bone density was developed. The values of repeated measurements taken at identical locations did not vary by more than 2%. Using this technique, bone density of the lower tibia was measured in 39 men and 36 women; 14 had been affected by an injury to a knee or calf and immobilized five to eight years prior to this investigation. The measured values demonstrated an impressive equality between the tibiae of each individual and between the two sexes up to 50 years of age. However, these values correlated poorly with the bone density of the distal radius. In women older than 50 years of age, bone density decreased. Bone density was also low in all postinjury limbs. When compared with radiographic and bone mineral content (BMC) measurements of the same limb at the same location, the bone density measurements were useful and reduced the range of uncertainty of diagnosing osteoporosis by radiography only. Little or no correlation was found between bone density values and BMC measurements. The Compton scattering technique may become a precise and sensitive method for the clinical diagnosis of postinjury osteoporosis and quantitation of the long-term effects of limb injuries.

Adolescent↗
PubMedDate not supplied

Hyoid bone syndrome and its treatment with nonsteroidal anti-inflammatory drugs.

PURPOSE: Nonspecific cervical pain is a common complaint in primary ear, nose, and throat clinic patients. In some cases, hyoid bone syndrome has been recognized as the cause of the complaint. Our study describes this common but unrecognized syndrome and suggests a treatment with nonsteroidal anti-inflammatory drugs (NSAIDs), a method of treatment not previously reported for this syndrome. PATIENTS AND METHODS: Patients with suspected hyoid bone syndrome (38) were treated with oral NSAIDs and/or with an NSAID ointment for topical application. RESULTS: Symptomatic relief was obtained in 66% of our patients and in 71% of the patients treated by NSAID tablets. Symptomatic relief was obtained in 91% of the patients with symptom durations of less than 6 weeks. CONCLUSION: We recommend a course of NSAID therapy as the first method of treatment for this syndrome before treatment with invasive procedures, especially for patients with symptom durations of less than 6 weeks. Better recognition of the hyoid bone syndrome will result in a more effective treatment and will avoid an unnecessary investigation.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

Halitosis: an interdisciplinary approach.

PURPOSE: To summarize the experience in our halitosis clinic, emphasizing an interdisciplinary approach. PATIENTS AND METHODS: Thirty-nine patients with a primary complaint of halitosis were evaluated. Their health was established by a questionnaire, by clinical examination, and by laboratory analysis. Halitosis was evaluated organoleptically by a dentist and an otolaryngologist (odds ratio [OR] = 5.7). The volatile sulfide levels were measured with a portable sulfide monitor (Halimeter; RH-17 series, Interscan, Chatsworth, CA). RESULTS: The patients were found to suffer from otolaryngological disorders (26%), dental problems (23%), oral discomfort (18%), and gastrointestinal pathology (10%), or several of the above. In 31% of the patients, however, no clinical involvement was detected. The salivary flow rates in the patients were similar to those in healthy controls, whereas their oral Candida carrier rate was low (28%). Fifty-seven percent of the patients had objective halitosis by organoleptic evaluation and 61% by Halimeter measurement. CONCLUSION: A high percentage of the patients who came to the clinic with a primary complaint of halitosis did not have a detectable problem.

Adolescent↗