Search PubMed⌕ Search

Biomedical subjects

J Fuhrer

Publications and source records attributed to J Fuhrer.

At least 55 records · Page 3Linked to original sources
PubMed1994

Effects of ozone on managed pasture: II. Yield, species composition, canopy structure, and forage quality.

Managed pasture composed of grasses, clover and weeds was exposed in open-top chambers to different levels of ozone (O(3)) during two consecutive seasons to study changes in yield, species composition, canopy structure, and forage quality. The pasture was established in 1990 and exposed in 1991 and 1992. Ozone treatments included charcoal-filtered air (CF), non-filtered air (NF), and two treatments with O(3) added to NF air during periods with global radiation >/= 400 W m(-2) (NF(+), NF(++)). The ratio between the 2-year cumulative, radiation-weighted O(3) concentration in ambient air (= 365 microl litre(-1) h) and in the different treatments was 0.50 (CF), 0.85 (NF), 1.11 (NF(+)), and 1.64 (NF(++)). Plots were harvested four times in 1991, and five times in 1992. The total forage yield for both seasons was modified little by O(3). The yield reduction in NF(++) was only 10% as compared to the CF treatment. Also, only marginal changes were observed in forage quality (Ca, crude protein, crude fibre), and in leaf area index and fractional light penetration. Ozone strongly reduced the yield of clover (Trifolium repens L. and Trifolium pratense L.). The O(3)-effect on clover growth was small after the first harvest and increased with each growth period. In NF, the 2-year cumulative clover yield was reduced by 24% relative to CF. In NF(++), clover growth almost ceased near the end of the second season. The reduction in clover yield with increasing O(3) was associated with a slight increase in the yield of grasses (mainly Dacytlis glomerata L). The increase in the proportion of invading species (weeds or herbs) (Taraxacum officinale L.) during the experiment was not significantly affected by O(3). A second order polynomial function was fitted to the data to establish an exposure-response model for the cumulative clover yield and the cumulative, radiation-weighted O(3) dose, and linear models were developed for total forage mass, grass yield and yield of weeds. Reducing O(3) from elevated levels (NF(+) and NF(++)) during the first season to near-ambient levels (NF) during the second season resulted in a significant recovery of clover yield after two re-growth periods. It is concluded that continuous exposure to ambient levels of O(3) negatively affects the yield of clover in frequently cut, managed pasture, but because of the relatively small proportion of clover, the shift in species composition only marginally affects total forage yield and forage quality. It is emphasised, however, that limitations of the experimental system must be taken into account before extrapolations to real field situations can be made.

Journal Article↗
PubMed1994

In situ detection of PCR-amplified HIV-1 nucleic acids in lymph nodes and peripheral blood in patients with asymptomatic HIV-1 infection and advanced-stage AIDS.

This study determined the in situ detection rate of polymerase chain reaction (PCR)-amplified human immunodeficiency virus type 1 (HIV-1) DNA and RNA in lymph nodes and peripheral blood CD4+ cells in six patients with asymptomatic HIV-1 infection and from six people who died of advanced AIDS. The lymph nodes of patients with asymptomatic infection showed expanded germinal centers where, on average, 20% of the CD21+ dendritic cells contained HIV-1 DNA. From 5 to 80% of the CD4+ cells in these lymph nodes contained HIV-1 DNA, as compared with 1-11% of the CD4+ peripheral blood mononuclear cells. The infection in most cells was latent in the asymptomatic group. In contrast, the lymph nodes of patients with advanced AIDS showed marked depletion of both dendritic and CD4+ cells. The majority of the remaining CD4+ cells in the lymph nodes and blood showed PCR-amplified viral DNA and cDNA sequences suggesting the presence of genomic and multiple spliced transcripts. It is concluded that asymptomatic HIV-1 infection is associated with a wide range of latent to active viral-positive CD4+ lymphocytes and dendritic cells in the lymph nodes. Progression to AIDS is characterized by active viral replication in many of the remaining CD4+ cells in the lymph nodes and blood.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Cytomegalovirus colitis in patients with acquired immunodeficiency syndrome.

The spectrum of presentation of complications in patients with human immunodeficiency virus (HIV) disease is changing, in line with their improved survival. Infection of the colon with cytomegalovirus (CMV) is now more commonly encountered in clinical practice. We have reviewed the medical records of eleven patients with clinical and pathological evidence of CMV colitis. The clinical presentation, endoscopic and histological findings, and simultaneous infection of other organs with CMV are discussed. Diarrhoea in association with abdominal pain is the most frequent symptom complex in these patients and should raise the clinical index of suspicion for CMV colitis.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Toxoplasmic encephalitis in patients with the acquired immunodeficiency syndrome. Members of the ACTG 077p/ANRS 009 Study Team.

BACKGROUND: In patients with the acquired immunodeficiency syndrome (AIDS), toxoplasmic encephalitis is usually a presumptive diagnosis based on the clinical manifestations, a positive antitoxoplasma-antibody titer, and characteristic neuroradiologic abnormalities. A response to specific therapy helps to confirm the diagnosis, but it is unclear how rapid the response should be. We studied the course of patients treated for acute toxoplasmic encephalitis and evaluated objective clinical criteria for this empirical diagnosis. METHODS: A quantifiable neurologic assessment was used prospectively to evaluate the clinical outcome of patients with AIDS and toxoplasmic encephalitis who were treated with oral clindamycin (600 mg four times a day) and pyrimethamine (75 mg every day) for six weeks. RESULTS: Thirty-five of 49 patients (71 percent) responded to therapy, and 30 of these (86 percent) had improvement by day 7. Thirty-two of those with a response (91 percent) improved with respect to at least half of their base-line abnormalities by day 14. Improvement in neurologic abnormalities within 7 to 14 days after the start of therapy was strongly associated with the neurologic response at 6 weeks. The four patients in whom treatment failed and the two patients with lymphoma had progressing neurologic abnormalities or new abnormalities during the first 12 days of therapy. Nonlocalizing abnormalities (headache and seizure) improved regardless of the clinical outcome. CONCLUSIONS: Oral clindamycin and pyrimethamine are an effective treatment for toxoplasmic encephalitis. Patients who have early neurologic deterioration despite treatment or who do not improve neurologically after 10 to 14 days of appropriate antitoxoplasma therapy should be considered candidates for brain biopsy.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Dangerous arrhythmias].

The usual frequent tachyarrhythmias well known to the specialists in internal medicine, such as ventricular tachycardia and ventricular fibrillation, are not discussed in this publication; nor are the bradycardias connected with the sick sinus syndrome or with atrioventricular block of higher degrees (with one exception). In the first section a stratification of the risk after myocardial infarction is presented including the therapeutic implications. Severely reduced left ventricular function is of most negative prognostic value. After the poor results of the CAST study, which revealed a threefold greater mortality of patients with myocardial infarction and severely impaired left ventricular function under treatment with some antiarrhythmic agents of class I (Vaughan Williams), compared to patients on placebo, cardiologists have resorted to beta-blocking agents again or, in patients with severely reduced left ventricular function, to amiodarone (Cordarone), based on preliminary results of current amiodarone studies. For selected patients, implantable cardioverter-defibrillator (ICD) devices seem to have a promising future. In the second part some rare and persistent arrhythmias are mentioned that may induce heart failure in an otherwise healthy heart, such as ectopic atrial tachycardia, atrioventricular junctional tachycardia with RP > PR, His bundle tachycardia and idiopathic ventricular tachycardia (this arising only in infants). In the third section some infrequent forms of tachycardia are discussed that may be sporadically encountered in a medical office. Ventricular tachycardia of the type "torsades de pointes" is associated with on a prolonged QT or QTU time in the ECG and is mainly due to drugs (especially antiarrhythmic agents). The therapy consists in withdrawal of the drug and may include magnesium intravenously and even a temporary pacemaker. The tachycardias associated to the Wolff-Parkinson-White syndrome have gained more practical importance since it has become possible to localize the accessory pathway involved by mapping with subsequent interruption by surgery or ablation. In atrial fibrillation with an ECG pattern of delta waves at the beginning of QRS complexes, digitalis and verapamil are contraindicated since they may induce ventricular fibrillation. The Mobitz type is one, and the most rare, form of the three atrioventricular blocks of second degree. It is almost always combined with an infra-His-bundle conduction disturbance in the conducted beats, and is an immediate precursor of complete atrioventricular block. Patients with the Mobitz block usually need a pacemaker. Finally, two case reports are presented to show that superficial and incorrect diagnosis of an arrhythmia is followed by incorrect and dangerous therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1992

[Myocardial infarct without classical Q-waves in the ECG].

In this article the ECG pattern of myocardial infarction not associated with the commonly seen pathologic Q waves (greater than 0.03 s) or QS waves is discussed. In a short introduction the differential diagnosis of pathologic Q or QS waves is recalled. Thereafter, the authors insist on their experience, that the diagnosis of infarction should generally be based on the combination of RIsk factors, THOracic pain, a pathologic ECg and elevated cardiac ENzymes. Therefore, the diagnosis of a myocardial infarction should be made only, if it is 'RITHOCGENE' (abbreviation of the above-mentioned combination). The typical or possible 'non-Q-wave infarction' ECG patterns are listed, including a normal ECG.

Aged↗
PubMed1992

Luetic cervical adenitis in patients with human immunodeficiency virus type 1 infection.

The clinical course of syphilis may be altered in some patients with human immunodeficiency virus type 1 infection. We report two cases of syphilis in patients with human immunodeficiency virus type 1 infection who presented with marked unilateral anterior cervical adenopathy after engaging in oral-genital sex. Neither of the patients had evidence of oropharyngeal chancres. One patient developed a cutaneous rash of secondary syphilis soon after the cervical adenopathy developed. Both patients responded well to antibiotic therapy.

Adult↗
PubMed1992

Pilot study comparing the salivary cationic protein concentrations in healthy adults and AIDS patients: correlation with antifungal activity.

This investigation compared the salivary cationic protein concentrations of 12 healthy adult controls with those of 12 hospitalized patients with AIDS. Salivas were quantified by capillary electrophoresis using purified cationic protein standards. In parotid saliva, histidine-rich polypeptides (HRPs) 1-6, histatin 6, and lysozyme concentrations were determined. In addition to these eight cationic proteins, submandibular-sublingual saliva was also quantified for histatin 2 and the histatin 2 degradation product. When comparisons were made on the basis of individual proteins, the HRP-histatin concentrations in the AIDS patients showed either statistically significant decreases or a decreasing trend compared with healthy adult controls. When HRP-histatin concentrations were summed for each patient, there were statistically significant differences between the healthy adult controls and the individuals with AIDS in both parotid and submandibular-sublingual salivas. Closer examination revealed that some individuals with AIDS had HRP-histatin concentrations that fell within the normal range of the healthy adult controls. For these individuals, lower than expected salivary antifungal values were obtained. Either decreasing histidine-rich protein concentrations and/or an inability of these proteins in saliva to interact with Candida albicans may contribute to the defective salivary antifungal activity seen in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Determination of salivary anticandidal activities in healthy adults and patients with AIDS: a pilot study.

This investigation compared the salivary anticandidal activities of 12 healthy adults with 12 hospitalized patients with AIDS. Stimulated parotid, submandibular-sublingual, and whole salivas were collected during a period of 10 min, immediately acidified, boiled, and then centrifuged to isolate salivary supernatants. Supernatants were then tested for antifungal activity against Candida albicans in blastospore viability inhibition and germ tube formation assays. A unit of blastospore or germ tube antifungal activity was established as that activity yielding 90% or greater inhibition during a defined time period in each salivary assay. Each of the patients with AIDS were found to be defective in one or more of their salivary antifungal activities, and in comparison with healthy adults the differences in antifungal units per milliliter of saliva and total antifungal units were statistically significant for each saliva and each antifungal assay. Defective salivary antifungal activity may contribute to the oral candidiasis seen in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Influence of Ozone on the Stable Carbon Isotope Composition, deltaC, of Leaves and Grain of Spring Wheat (Triticum aestivum L.).

The relative composition of stable carbon isotopes, delta(13)C, was determined in flag leaves and grain of spring wheat (Triticum aestivum L. cv Albis) grown in open-top field fumigation chambers and exposed to different O(3) levels during the growing season. The aim of the study was to establish exposure-response relationships for the radiation-weighted seasonal mean O(3) concentration and delta(13)C (relative deviation of the (13)C/(12)C ratio) values of the two plant parts. Samples were collected at harvest in 1986, 1987, and 1988. With increasing O(3) concentration, delta(13)C values increased (became less negative) proportionally. Year to year delta(13)C differences at equivalent O(3) concentrations were small. The shift in delta(13)C caused by O(3) was more pronounced in grain than in leaves. According to models of (13)C discrimination in C(3) plants, these results indicate increasing limitation of photosynthesis by CO(2) diffusion relative to limitation by carboxylation with increasing O(3) exposure. This conclusion is not in agreement with results from gas exchange analysis. Water use efficiency in green flag leaves tended to decrease with increasing O(3), indicating a dominating effect of O(3) on CO(2) carboxylation.

Journal Article↗
PubMed1991

Factors determining pulmonary deposition of aerosolized pentamidine in patients with human immunodeficiency virus infection.

Although aerosolized pentamidine (AP) has recently been approved for prophylaxis and is undergoing clinical trials for treatment of pneumocystis, pneumonia (PCP), factors important in the deposition of AP have not been described. Using radioaerosol techniques, deposition was measured in 22 patients receiving AP for prophylaxis or treatment of PCP. In all patients total and regional deposition of pentamidine, breathing pattern, pulmonary function (PFT), regional ventilation, and type of nebulizer were analyzed. Bronchoalveolar lavage (BAL) was performed 24 h after inhalation to assess the relationship between pentamidine levels in BAL fluid and measured aerosol deposition. The nebulizers tested were the Marquest Respirgard II and the Cadema AeroTech II, both previously characterized in our laboratory. The aerosol particles consist of water droplets containing dissolved pentamidine and technetium 99m bound to albumin. Analysis of particles sampled during inhalation via cascade impaction confirmed a close relationship between radioactivity in the droplets and the concentration of pentamidine as measured by HPLC (r = 0.971, p less than 0.0001; n = 18). Deposition was measured by capturing inhaled and exhaled particles on absolute filters and measuring radioactivity. This technique allows the determination of the deposition fraction (DF, the fraction of the amount inhaled that is deposited), which provides information on factors strictly related to the patient. To confirm the filter measurements, pentamidine deposition was also measured by gamma camera. The camera measurement was possible because each patient's thoracic attenuation of radioactivity was determined by a quantitative perfusion scan (mg pentamidine deposited via both techniques, r = 0.949, p less than 0.0001; n = 26). Regional lung volume and ventilation were determined by xenon 133 equilibrium scan and washout. Pentamidine deposition varied markedly between patients, but BAL levels of pentamidine significantly correlated with measured deposition (r = 0.819, p less than 0.01; n = 9). DF averaged 0.621 +/- 0.027 (SEM) and did not correlate with any measured lung parameter, including breathing pattern and PFT. Regional deposition did not correlate with regional ventilation. The major factor influencing pentamidine deposition was aerosol delivery (mg deposited versus mg inhaled; r = 0.963, p less than 0.0001; n = 26). The nebulizer was an important determinant of aerosol delivery, with the AeroTech delivering between 2.5 and 5 times more drug than the Respirgard. These observations are important in assessing treatment failure and cost of therapy.

Aerosols↗
PubMed1991

Disseminated sporotrichosis in patients with AIDS: case report and review of the literature.

Sporotrichosis is the disease caused by the dimorphic fungus Sporothrix schenkii. Disseminated sporotrichosis is an uncommon infection which usually occurs in alcoholics or patients receiving immunosuppressive medication. We report a case of a patient with AIDS who had disseminated sporotrichosis which was progressive and fatal despite antifungal therapy. Four previously reported cases of disseminated sporotrichosis in patients with AIDS are reviewed. Disseminated sporotrichosis occurs in patients with HIV-1 infection and severe CD4 lymphocyte depletion. It usually presents with diffuse cutaneous lesions and is associated with polyarticular arthritis. Response to treatment is variable and chronic suppressive therapy is probably needed to prevent relapse.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Effects of ozone on the grain composition of spring wheat grown in open-top field chambers.

In a three-year study carried out at a rural site in Switzerland, spring wheat (Triticum aestivum L. cv. Albis) was exposed to different levels of ozone (O(3)) in open-top-field chambers from the two-leaf stage until harvest. Field plots in ambient air (AA) were used for comparison. Grain recovered from the different treatments was analyzed for minerals (Ca, Mg, K, P), starch, protein, amino acids and alpha-tocopherol, in order to investigate the effect of O(3) on grain composition. Chamber-enclosure had small effects on some parameters (K, protein), but not on others (starch), as shown by the comparison of data from the AA and non-filtered-air treatment (NF). Differences between NF and charcoal-filtered air (CF) were very small. At O(3) concentrations higher than in the NF treatment (O(3)-1 = 1.5xNF and O(3)-2 = 2.5xNF), mineral contents were higher than in the NF and CF treatments. Protein content was increased only in the O(3)-2 treatment. Starch contents decreased from about 63% in the CF treatment to 54% in the O(3)-2 tratment. No effect of O(3) on the content of alpha-tocopherol and on the essential amino acid index of the protein was observed. It is concluded that compositional changes in wheat grain in response to O(3) are minor, and that ambient O(3) is not likely to cause important changes.

Journal Article↗
PubMed1990

Ventricular tachycardia in two patients with AIDS receiving ganciclovir (DHPG).

We report two cases of patients who developed ventricular tachycardia while receiving intravenous infusions of ganciclovir [9-(1,3-dihydroxy-2-propoxy)methylguanine, DHPG]. Worsening cytomegalovirus infection prompted renewal of ganciclovir therapy under close cardiac monitoring in one of these patients, and ventricular tachycardia recurred. The close temporal relationship between administration of the drug and onset of the arrhythmias in conjunction with the absence of other factors known to predispose to arrhythmias suggest that ganciclovir may have played a role in the development of arrhythmias in these patients. The clinical courses of the patients are discussed, as are autopsy results.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Effects of ozone on the yield of spring wheat (Triticum aestivum L., cv. Albis) grown in open-top field chambers.

Spring wheat (Triticum aestivum L., cv. Albis) was grown in the field at a site located in central Switzerland, and exposed to chronic doses of ozone (O(3)) in open-top chambers to study impacts on yield. The experiment was carried out in 1986, 1987 and 1988. The treatments used included charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air to which constant amounts of O(3) (two levels, O(3)-1 and O(3)-2) were added daily from 09.00 until 17.00 local time. Mean solar radiation-weighted O(3) concentrations during the fumigation period were in the range 0.016-0.022 microl litre(-1) (CF), 0.036-0.039 microl litre(-1) (NF), 0.057-0.058 microl litre(-1) (O(3)-1, used in 1987 and 1988 only) and 0.078-0.090 microl litre(-1) (O(3)-2). Fumigation was maintained from the three-leaf stage until harvest. Ambient plots were used as a reference. Plant characteristics examined included straw yield, grain yield, number of grains per head, number of heads per surface area, weight of individual grains and harvest index (ratio of grain weight to total dry weight). Pollutant concentrations and other environmental parameters were monitored continuously inside and outside the chambers. In 1986 and 1987, enclosure mostly increased the values of different parameters, while in 1988, they were decreased. The negative enclosure effect was due to extremely turbulent winds, which caused lodging inside the chambers. In all 3 years, increasing O(3) concentrations negatively affected the parameters studied, except for the number of heads per surface area, which showed no treatment response. Grain yield showed a very sensitive response to O(3). The effect of O(3) on grain yield was due to an effect primarily on grain size and secondarily on grain number. The relative response of grain yield to O(3) was similar in all 3 years, despite year-to-year differences in climatic conditions and enclosure effects. The analysis of the data for combined years revealed an increase of about 10% in grain yield due to air filtration. The corresponding increase in straw yield was only about 3.5%. Exposure-response models were developed for individual years and combined years. It is concluded that, in the study area, ambient O(3) may affect grain yield in spring wheat.

Journal Article↗
PubMed1989

Clinical impact of rapid identification and susceptibility testing of bacterial blood culture isolates.

Two hundred twenty-six patients with bacteremia were prospectively enrolled in a randomized trial that was performed to determine the clinical impact of the receipt of in vitro microbiological data by the physician soon after organism detection as opposed to having the physicians wait until similar data were available by routine methods. Identification and antibiotic susceptibility patterns of 110 isolates were determined by direct inoculation of the Vitek AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.) with a sample from a positive blood culture vial. One hundred sixteen isolates were processed by routine methods. Microbiological results were available within an average of 8.8 h by the direct method versus an average of 48 h by the routine method. In both groups an infectious disease fellow used the information to make therapeutic recommendations to the responsible physician. When compared with that provided by the routine method, the information provided by the direct method was significantly more likely to result in an initiation of antibiotic therapy, a change to more effective therapy, or a change to less expensive therapy. Recommendations were significantly more likely to be followed in patients whose isolates were processed by the direct method versus the routine method. A projected savings of $158 per patient was estimated for the patients who were changed to less expensive therapy or in whom antibiotics were discontinued because results were available sooner. These cost savings, coupled with changes in therapy made for reasons of efficacy, support the usefulness of the earlier reporting of the identity and antibiotic susceptibility patterns of bacterial blood culture isolates.

Bacteria↗
PubMed1989

[Effect of bromocryptin in polycystic ovary syndrome].

Ten patients with polycystic ovarian disease and normoprolactinemia received bromocriptine 5 mg daily for up to 4 months. The following parameters were evaluated before treatment and at monthly intervals menstrual patterns, hirsutism score, weight, and blood pressure and LH, FSH, prolactine, unbound and total testosterone in plasma. In 5 out of 10 subjects with oligomenorhea or amenorhea normal menstruations were observed; 3 additional subjects got more frequent but not normal menstruation and 2 patients got pregnant. No changes in LH, FSH and androgens were observed. Prolactin levels fell significantly in all subjects. No clinical nor biochemical parameter predicted the improvement in menstrual patterns. Bromocriptine may have a place in the treatment of polycystic ovarian diseases with normoprolactinemia though its mechanism of action is unclear.

Adolescent↗