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Biomedical subjects

J Lindemann

Publications and source records attributed to J Lindemann.

At least 19 recordsLinked to original sources
PubMed2004

Immediate effect of benzalkonium chloride in decongestant nasal spray on the human nasal mucosal temperature.

Benzalkonium chloride is a preservative commonly used in nasal decongestant sprays. It has been suggested that benzalkonium chloride may be harmful to the nasal mucosa. Decongestion with the vasoconstrictor xylometazoline containing benzalkonium chloride has been shown to cause a significant reduction of the nasal mucosal temperature. The purpose of the present study was to determine the short-term influence of xylometazoline nasal spray with and without benzalkonium chloride on the nasal mucosal temperature. Healthy volunteers (30) were included in the study. Fifteen volunteers received xylometazoline nasal spray (1.0 mg/mL) containing benzalkonium chloride (0.1 mg/mL) and 15 age-matched subjects, received xylometazoline nasal spray without benzalkonium chloride. Using a miniaturized thermocouple the septal mucosal temperature was continuously measured at defined intranasal detection sites before and after application of the nasal spray. The mucosal temperature values did not significantly differ between the group receiving xylometazoline containing benzalkonium chloride and the group receiving xylometazoline spray without benzalkonium chloride before and after decongestion (P > 0.05). In both study groups septal mucosal temperatures significantly decreased after decongestion (P < 0.05) because of a reduction of the nasal mucosal blood flow following vasoconstriction. This study indicates that benzalkonium chloride itself does not seem to influence nasal blood flow and nasal mucosal temperature in topical nasal decongestants.

Administration, Inhalation↗
PubMed2004

Numerical simulation of air temperature and airflow patterns in the human nose during expiration.

Recovery of heat and water during expiration is an important but not yet fully understood function of the nose. The presented study investigated cooling of the expiratory air for heat recovery within the human nose applying numerical simulation. A numerical simulation in a bilateral three-dimensional model of the human nose based on computed tomography was employed. Temperature distribution and airflow patterns during expiration were displayed. Cooling of the expiratory air primarily takes place in the areas of inferior and middle turbinate. Areas of the highest decrease in temperature are characterized by turbulent airflow with vortices of low velocity. Numerical results showed good concordance with experimental in vivo temperature measurements. Heating of inspired air not only depends on inspiration but also on expiration. Cooling the warm expiratory air may be regarded as an important factor for heat recovery. Furthermore, the results demonstrate the close relation between heat exchange and airflow patterns.

Exhalation↗
PubMed2003

The impact of expiration on particle deposition within the nasal cavity.

One of the most important functions of the nose is cleansing the inspired air. The aim of this study was to compare the intranasal deposition of particles during inspiration and expiration, applying different breathing manoeuvres. In nine subjects, the non-deposited particles during inhalation of an aerosol of starch particles were laser-optically detected by placing a suction probe transnasally in the anterior nasal segment. The particle deposition was measured during cyclical nose-in/nose-out (nose-only) and nose-in/mouth-out breathing. The deposited fraction was calculated in percentages. Active anterior rhinomanometry and acoustic rhinometry were performed. The mean deposited fraction in the anterior nasal segment was statistically significantly higher (P < 0.02) during nose-only breathing (46.0%) compared with nose-in/mouth-out breathing (33.0%). Our results suggest that intranasal particle deposition takes place during inspiration as well as during expiration. The period of expiration does not only seem to be important for water and heat recovery, but also for cleansing of the respiratory air.

Administration, Inhalation↗
PubMed2003

The relationship between water vapour saturation of inhaled air and nasal patency.

The nasal cavity volume and the temperature of the nasal mucosa are considered to be the most important predictors of nasal conditioning. The aim of this study was to assess the relationship between the intranasal degree of water vapour saturation of inhaled air and nasal patency. Intranasal humidity values at different locations within the nasal cavity of 15 healthy subjects were compared to nasal airway resistance detected by active anterior rhinomanometry (AAR). Repeated measurements were carried out during one day to obtain varying nasal cavity volumes due to the nasal cycle. The end-inspiratory humidity data were obtained with a miniaturised capacitive humidity sensor at defined detection sites within the anterior nasal segment without interruption of nasal breathing. Measurements were carried out at four different times during one day. The degree of water vapour saturation did not correlate with the values of the AAR at any intranasal detection site and time of detection during one day. The study supports the view that there is no correlation between the degree of water vapour saturation within the anterior nasal segment and the nasal resistance during the nasal cycle over the day. Although nasal patency varies because of the nasal cycle, the changes of nasal cavity volume due to the nasal cycle do not seem to influence the degree of water vapour saturation of the inspiratory air.

Adult↗
PubMed2002

[Sense of smell before and after functional esthetic rhinoplasty].

BACKGROUND: The aim of the present study was to determine possible changes in olfactory threshold after functional and esthetic nasal operations and to evaluate whether these changes were recognized by the patients. METHODS: The study included 41 patients before and after nasal surgery (septoplasty, septorhinoplasty). Nasal airway resistance, olfactory thresholds, and subjective symptom scores were evaluated and compared pre- and postoperatively. The mean follow-up was 5.4 months. Olfactory performance was assessed using the Sniffin' Sticks. RESULTS AND CONCLUSIONS: The postoperative values in the screening test for olfactory sensitivity were not significantly different from those before nasal surgery. Nasal ventilation was improved postoperatively in all patients, assessed by determination of nasal airway resistance and subjective symptom scores. Besides an increase in nasal ventilation, functional and esthetic nasal operations can lead to improvement of olfactory function. The rarely seen postoperative increase in olfactory threshold does not seem to be subjectively recognizable by the patients.

Adolescent↗
PubMed2002

Nasal mucosal temperature during respiration.

One of the most important functions of the nose is heating the inspiratory air. The aim of the present study was to measure nasal mucosal temperature at defined intranasal sites during respiration, without interruption of nasal breathing. A total of 15 healthy volunteers was included in the study. A miniaturized thermocouple was used for continuous detection of the septal mucosal temperature in the nasal vestibule, the nasal valve area, the anterior turbinate area and the nasopharynx during respiration. The highest temperature values were measured at the end of expiration, the lowest values at the end of inspiration with a statistically significant difference (P < 0.005). Mean mucosal temperature ranged from 30.2 +/- 1.7 degrees C to 34.4 +/- 1.1 degrees C. Statistically there were significant differences between the detection sites during inspiration and expiration (P < 0.05). In our study, the temperature values of the nasal mucosa depend on the intranasal detection site and the respiratory cycle. We therefore conclude that whenever data of nasal mucosal temperature are published, it is absolutely essential to describe the precise site of detection and to give information about the time of detection in the respiratory cycle.

Adult↗
PubMed2001

Unusual neck mass in an adolescent: benign basal cell adenoma of the minor salivary glands of the piriform sinus.

With an incidence of less than 3%, salivary gland tumors are rare in the head and neck. The percentage of basal cell adenomas within the group of salivary gland tumors is even less (0.2-2%). Salivary gland tumors occur very rarely in adolescents. The basal cell adenoma commonly affects older persons and occurs most frequently in the major salivary glands. We present the unusual case of a benign basal cell adenoma of the minor salivary glands of the piriform sinus in a 14 year old male patient. Unusual are the age of the patient, the histological type, size and localisation of the tumor.

Adenoma↗
PubMed2001

[Endonasal temperature and humidity profile after exposure to various climate-controlled inspiratory air].

BACKGROUND AND OBJECTIVE: The nose as the first segment of the upper respiratory tract is exposed to different climatic conditions of the ambient air. The purpose of this study was to determine whether nasal air conditioning of ambient air is influenced by a short-term exposure to air of different climatic conditions. PATIENTS AND METHODS: Fifteen healthy volunteers were enclosed into the study. A miniaturised humidity sensor and thermocouple was used for detection of humidity and airway temperature at three detection sites within the anterior nasal cavity. Both parameters were measured at the end of inspiration during breathing of ambient air after exposure to cold dry air, "normal" ambient air, and warm humid air for 10 minutes. RESULTS: The end-inspiratory intranasal humidity during breathing of ambient air increased at all locations within the nose when the temperature and humidity of the exposure condition increased. At the most anterior detection site, the effect of increase in humidity after exposure to the different climatic conditions was the most pronounced. The increase in intranasal temperature had no relation to the different climatic conditions during the short-term exposure. CONCLUSIONS: The results suggest that nasal humidification in ambient air can be influenced by short-term exposure to air of extreme temperature and humidity prior to breathing of ambient air.

Adult↗
PubMed2001

Detection of particles within the nasal airways before and after nasal decongestion.

Cleansing of the air is one of the most important functions of the nose. The aim of this investigation was to determine the influence of decongestion of the nasal mucosa with xylometazoline on the intranasal particle deposition at different sites of the nasal cavity. During respiration of an aerosol of starch particles, the non-deposited particles in the air were laseroptically detected in 10 healthy volunteers by a transnasally placed suction probe at different locations within the nasal cavity. The anterior nasal segment was the main area of intranasal particle deposition before and after decongestion of the nasal mucosa. Particle deposition after nasal decongestion was not significantly different from the values before application of xylometazoline. Decongestion of the nasal mucosa and increase in nasal cavity diameter seems not to influence particle deposition of inhaled and exhaled air within a short period after onset of the maximal decongestive effect of xylometazoline.

Adult↗
PubMed2001

Intranasal temperature and humidity profile in patients with nasal septal perforation before and after surgical closure.

Common complaints of patients with a nasal septal perforation are crusting, dryness and bleeding. As shown previously, intranasal humidity values are significantly lower in patients with a septal perforation compared with healthy volunteers. The aim of this study was to determine the influence of surgical closure of septal perforations on intranasal temperature and humidity, and to evaluate changes in clinical symptoms after surgery. Ten patients with septal perforations were included in the study. Intranasal temperature and humidity were measured at the nasal valve and anterior turbinate areas before and after surgical closure. Clinical symptoms were assessed using a nasal symptom score. The end-inspiratory humidity values were significantly (P < or = 0.05) higher postoperatively than preoperatively. The increase in temperature at the anterior turbinate area was significantly higher postoperatively. The temperature values at the nasal valve area were not significantly different. Recurrent epistaxis and nasal dryness were reduced after surgery. Nasal septal perforations disturb the intranasal temperature and humidity profile. After surgical closure, heating and humidification is improved. This may be responsible for the reduction of frequent complaints such as bleeding and dryness.

Adult↗
PubMed2001

[Juvenile hyaline fibromatosis (JHF)].

The juvenile hyaline fibromatosis (JHF) is a rare tumorous autosomal recessive disease of the connective tissue. The etiopathogenesis of the disease is unknown. Typical diagnostic criteria are multiple hyaline subcutaneous fibroma, filamentous tumors of the skin, gingival hypertrophy, muscle contractures of the extremities and multiple osteolytic bone destructions. Involvement of visceral organs is not described. Mental development and life expectancy are normal. Until today, no causal treatment of the JHF exists. Surgical excision of the dermal tumors is indicated for functional and aesthetic improvement. Complete excision should be executed in the early phase of their development. This has shown the best functional and aesthetic results, especially in facial areas. The progress of the disease is individual. Due to frequent recurrencies, repeated resections and revisions may be necessary. Interdisciplinal counseling and therapy, particularly physiotherapy, may partially improve the state of function.

Child, Preschool↗
PubMed2001

Medical education through community experience: community projects at the University of South Dakota School of Medicine.

Community projects are a requirement of third-year medical students at three South Dakota clinical campuses. Students identify a community issue, design and implement either a service or research project, and present the project to faculty and peers. Topics include cardiovascular and other disease risk factors, nutrition education, firearm safety and many others. These projects answer a need to advance an understanding of population health, promote community involvement among student physicians, and improve the health of the community.

Clinical Clerkship↗
PubMed2001

Temperature and humidity profile of the anterior nasal airways of patients with nasal septal perforation.

INTRODUCTION: The most frequent symptoms of patients with nasal septal perforations are crusting and bleeding. The aim of this study was to determine the influence of septal perforations on temperature and humidity of the anterior nasal airways. PATIENTS AND METHODS: Intranasal temperature and humidity were measured in the nasal valve area, the anterior turbinate area and in the nasopharynx during normal respiration. A miniaturized thermocouple and a humidity sensor were used for continuous detection. Ten patients with septal perforations were enclosed into the study. The results were compared to matched healthy control subjects. RESULTS: There were no significant differences of the temperature and humidity values between the left and right side of the nasal cavity in each study group. At the end of inspiration, nasal air temperature did not differ significantly between the two study groups. The humidity values at the end of inspiration were statistically significantly lower in the patient group. CONCLUSIONS: Nasal septal perforations seem to be related to lower humidity in the anterior nasal airways during inspiration. Reduced humidity may contribute to crusting as a main symptom.

Adult↗
PubMed2000

Detection of particles within the nasal airways during respiration.

This study introduces a new experimental setup for particle detection within the nasal airways and describes intranasal deposition of particles at various regions of the nasal cavity and the nasopharynx. During respiration of an aerosol of starch particles the nondeposited particles in the air were detected in 11 volunteers by a transnasally placed suction probe at numerous sites of the nasal cavity and nasopharynx. Another, identical suction probe measured the initial number of inhaled particles at the nostril. The two suction probes were connected to two identical laser particle counters and allowed calculation of particle deposition. Particles 1-3 microm in size were deposited to about 60% within the entire nasal cavity, whereas most of the particles 4-30 microm in size were deposited within the entire nasal cavity. Between 80% and 90% of the particles retained in the nasal cavity were deposited at the anterior nasal segment. Studies on deposition of various drugs within the nasal cavity using this experimental set-up are conceivable.

Administration, Inhalation↗
PubMed1993

Clinical characteristics of adolescent endometriosis.

Our study objective was to describe the appearance, stage, and treatment of endometriosis in adolescents undergoing laparoscopic treatment of severe dysmenorrhea and endometriosis. We designed a retrospective analysis of adolescents with endometriosis whose primary symptom was severe dysmenorrhea. We studied patients in a private practice associated with a residency program. Forty-nine adolescents with histologically confirmed endometriosis underwent laparoscopy. Thirty-six of these patients (mean age, 16.6 +/- 1.4 years; range, 13-20 years) presented with severe dysmenorrhea in a non-emergency state and were refractory to prior therapy. All patients underwent laparoscopic surgery. We classified endometriosis implants as typical implants, red lesions, and occult lesions in thirty-six adolescents. We excised infiltrating lesions (defined as implants penetrating greater than 3-5 mm) and vaporized or coagulated superficial lesions (defined as surface implants or those penetrating < 3 mm). All adolescents underwent postsurgical ovulation suppression with a daily birth control pill. The need for reoperation at any time or the use of GnRH analogs, Danazol, or large doses of progestins served to indicate treatment failure. The presence or absence of red lesions was recorded in this group and compared to the presence or absence of such lesions in an older population of patients undergoing definitive therapy for endometriosis during the same time period. Our results showed that red lesions are the predominant implant type in adolescents. Adolescents with cyclic pain and those who complain of abdominal pain, nausea, constipation, and diarrhea, during menses had the largest proportion of red lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

The impact of aluminium on green algae isolated from two hydrochemically different headwater streams, Bavaria, Germany.

Two strains of green algae (Scenedesmus sp. and Chlorella sp.) have been isolated from two headwater streams differing in stream chemistry (Eger river: acidic, low alkalinity; Püttlach river: slightly alkaline, high alkalinity). In this study the growth response of these indigenous algae to increased concentrations of aluminium (Al) is investigated. A semi-continuous culture technique was used for Al-toxicity studies. Algal response was determined by calculating growth rates from turbidity and cell counts. Those Al-species which are well known to be toxic were estimated by equilibrium calculations using the WATEQ computer program (Truesdall & Jones, 1973). The pH-value of the culture media was usually pH=5, except for one of the test series. Tested concentrations ranged from c=4 to 220 micromol litre(-1). The isolated strains of green algae were highly sensitive to increased Al-concentrations. The strain isolated from the Püttlach river was more sensitive than the Eger river algae. A total growth inhibition occurs at Al-concentrations of c=4 micromol litre(-1) if the whole Al was added at once. If Al was added gradually into the growth media the response of the algae was delayed. This is due to Al-enrichment in cells. In our long term toxicity studies, growth inhibition occurs even at nearly neutral pH-conditions (pH=6.5) although Al toxicity is expected at pH-values less than pH=5.5. This new result confirms the need of long-term studies in continuous cultures under simulated natural conditions. This might be the only way to achieve valid conclusions about the fate and the toxicity of environmental pollutants.

Journal Article↗