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Biomedical subjects

R Frei

Publications and source records attributed to R Frei.

At least 37 records · Page 2Linked to original sources
PubMed2001

Urine analysis performed by flow cytometry: reference range determination and comparison to morphological findings, dipstick chemistry and bacterial culture results--a multicenter study.

AIM: To validate whether quantitative flow-cytometric analysis of particulate matter in urine would allow for accurate and rapid enumeration of red blood cells (RBC), leukocytes (WBC), squamous epithelial cells (EC), casts, and bacteria, a Sysmex UF-100 analyzer was tested in a multicenter study. MATERIAL AND METHODS: At first, reference values were established and found to be < 14 for RBC, < 16 for WBC, < 9 for EC, < 2 for casts and < 173 for bacteria, respectively (counts per microl; 97.5 percentile). Due to the wide use of dipstick and microscopic sediment analysis in routine urine diagnostics, comparative studies on 950 random urine samples were performed. Bacterial counting combined with WBC enumeration was further compared in 266 routine urinary microbiologic cultures. RESULTS: Good correlations were found comparing UF-100 results of RBC (r = 0.89), WBC (r = 0.94), and EC (r = 0.74) with Fuchs-Rosenthal Chamber (FRC) counts. However, some misclassification of casts (r = 0.32) could be observed. Correlations of UF-100 with dipstick and sediment testing was significant (p < 0.001), but the scatter of the latter two methods is too wide to consider them as quantitative methods. Promising results further revealed that the analyzer has a good negative predictive value (NPV) for microbiologically negative cultures, especially for cultures with bacterial counts of 10(5)/l (NPV = 95%). CONCLUSION: The analyzer is capable of providing rapid and reliable urine analysis of cellular particles avoiding the known imprecision of dipstick and sediment methodology. Thus, when used in an algorithm, combined with dipstick or quantitative urine chemistry analysis (for hemoglobin, esterase, protein, glucose, etc.), this analyzer might serve as a rapid and accurate screening tool in routine urine analysis, thereby reducing manual reviewing rate as well as the number of missed samples, compared to screening with dipstick alone.

Adolescent↗
PubMed2000

[Epidemiology of septicemias in a university hospital over 5 yeaars].

Bloodstream infections (are associated with high mortality. The incidence of bloodstream infections is increasing worldwide, with a shift towards multiresistant pathogens such as methicillin-resistant Staphylococcus aureus, enterococci and Candida spp. This study analysed retrospectively 1814 episodes of bacteraemia from 1993 to 1997 at a single tertiary care centre. True bloodstream infections was defined as clinical sepsis and positive blood culture without evidence for contamination of skin bacteria. Of the 1814 episodes, 380 (20.9%) were contaminated, resulting in 1434 true episodes of bloodstream infection. 42% were nosocomial bloodstream infections and one fourth were primary bloodstream infections. The incidence of bloodstream infections increased from 13.0/10,000 patient-days (1993) to 15.8/10,000 patient-days (1997). Mortality increased from 15.4% (1993) to 21% (1997) (p = 0.059). The five most frequently isolated microorganisms were Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, coagulase-negative staphylococci and streptococci. The distribution of bacteria did not change over time from 1993 to 1998. Multiresistant bacteria such as methicillin-resistant Staphylococcus aureus, enterococci, Pseudomonas spp. and yeasts were isolated in less than 5% of episodes. In addition, there is a trend towards decreasing resistance, in contrast to most other institutions in Southern Europe and the US. Further analyses and studies are necessary to answer questions raised by this retrospective study.

Bacteremia↗
PubMed2000

[Inhaled colistin in cystic fibrosis].

UNLABELLED: The clinical course of cystic fibrosis (CF) is characterised by chronic bronchial infection with Pseudomonas aeruginosa. Therapy with inhaled aminoglycosides was introduced to decrease the rate of infectious exacerbations and to delay pulmonary progression. However, development of resistance to aminoglycosides is frequent. Few investigations are available into the resistance profile under treatment with colistin. Antibiotic resistance to colistin was analysed in 44 adult CF patients treated with inhaled colistin. Resistance to aminoglycosides was observed in 86% of cases (38/44) before therapy and decreased to 43% (19/44) under treatment with colistin. Five patients (11%) developed polymyxin resistance. After cessation of therapy pseudomonas became sensitive to polymyxin within a few months and enabled colistin to be reintroduced. In addition, we performed a pilot study analysing the effect of inhaled colistin on the growth of pseudomonas. The number of Pseudomonas aeruginosa decreased from 16.7 million (CFU) bacteria per ml sputum to 2.9 million under therapy with colistin. There was a more than tenfold increase in bacterial counts after inhaled colistin was stopped. Genotyping revealed no change in the type of pseudomonas strains. CONCLUSION: Development of resistance to polymyxin is not rare under long-term treatment with inhaled colistin and requires temporary interruption of therapy. Sputum cultures should therefore be tested regularly for polymyxin resistance in patients treated with inhaled colistin.

Administration, Inhalation↗
PubMed2000

[Leptospirosis: a frequently missed diagnosis? Epidemiology and diagnosis in Switzerland].

Clinical leptospirosis is rarely seen in Switzerland due to the climatic conditions. Nevertheless people may still suffer from leptospirosis, even to the extent of requiring intensive medical treatment. Variable symptoms and problematic diagnostics can make the diagnosis of leptospirosis difficult. Through two cases with varied symptoms, the clinical and diagnostic features of the disease are presented. In addition, the risk factors, the epidemiology and the diagnostic possibilities are discussed.

Adult↗
PubMed2000

Clinical impact of an infectious disease service on the management of bloodstream infection.

The impact of an infectious disease (ID) service on the optimal antibiotic management of 103 patients with bloodstream infections, defined as bacteremia and systemic inflammatory response syndrome, was evaluated. The optimal antibiotic management was defined according to the Sanford Guide to Antimicrobial Therapy (1996) or written internal guidelines. The judgment on optimal antibiotic management was made at the time of reporting the positive blood culture results. Switching from a broad-spectrum to a narrow-spectrum agent was carried out significantly more often by the ID service than by the attending physicians (25 of 25 vs. 20 of 40; P<0.001). In patients without empirical therapy, the ID service initiated optimal antimicrobial therapy significantly more often than physicians without training in infectious diseases (12 of 12 vs. 4 of 10, P=0.0028). Three of 12 patients in whom the attending physician misinterpreted the positive blood culture result needed 8 days to 4 months of additional hospitalization. In summary, patients for whom an ID service was provided received appropriate treatment more often and experienced significantly fewer complications.

Adult↗
PubMed2000

[Catamnestic study of ecological brief therapy].

Ecological brief psychotherapy has been practised at the Psychiatric Outpatient Clinic at the University Hospital Zurich since 1990. The aim is to use the development-oriented challenges posed by important others in the therapeutic process. The effectiveness of this form of therapy is investigated by reviewing the outcome of 28 completed treatment cases. While results at completion of therapy come up to the expectations, the long-term results were surprisingly positive. 96.4% of those surveyed reported they felt considerably better at final assessment 1 to 6 years after the therapy than they did at the beginning. Positive changes continued after the completion of therapy. We presume that our coevolutive focus brought resolution of blocked developmental steps in relationships that further stimulated changes that continued after the conclusion of therapy, even without further therapeutic support. Furthermore, the treatment effects provided by ecological brief psychotherapy apply to personality disorders as well.

Adult↗
PubMed2000

Psychotherapy of panic syndrome: focusing on ecological aspects of relationships.

Cognitive Behavioral Therapy (CBT) has been shown to be an effective symptomatic treatment for panic attacks; however, this paper recommends complementing it with an approach based on an interactive ecological model. The approach is based on the thesis that a panic syndrome can occur if patients block an impending and/or already initiated development of their relationships, especially involving partners or work. The case may be that, over a period of years, phobic attitudes and behavior described further in the text have enabled patients to maintain a socially positive shaping of their personal niches. Later, phobic avoidance behavior is no longer adequate due to the requirements of the new stage of life. Unconsciously, patients configure an outer relationship situation that demands of them the realization of the impending step in development. Therapy should utilize this relationship configuration.

Adult↗
PubMed1999

Loss of distal axons and sensory Merkel cells and features indicative of muscle denervation in hindlimbs of P0-deficient mice.

Mice lacking the major Schwann cell myelin component P0 show a severe dysmyelination with pathological features reminiscent of the Déjérine-Sottas syndrome in humans. Previous morphological and electrophysiological studies on these mice did not only demonstrate a compromised myelination and myelin maintenance, but were suggestive of an impairment of axons as well. Here, we studied the axonal pathology in P0-deficient mice by quantitative electron microscopy. In addition, we investigated epidermal receptor end organs by immunocytochemistry and muscle pathology by histochemistry. In proximal sections of facial and femoral nerves, axon calibers were significantly reduced, whereas the number of myelin-competent axons was not diminished in 5- and 17-month-old P0-deficient mice. However, in distal branches of the femoral and sciatic nerve (digital nerves innervating the skin of the first toe) the numbers of myelin-competent axons were reduced by 70% in 6-month-old P0-deficient mice. Immunolabeling of foot pads revealed a corresponding loss of Merkel cells by 75%, suggesting that survival of these cells is dependent on the presence or maintenance of their innervating myelinated axons. In addition, quadriceps and gastrocnemius muscles showed pathological features indicative of denervation and axonal sprouting. These findings demonstrate that loss of an important myelin component can initiate degenerative mechanisms not only in the Schwann cell but also in the distal portions of myelinated axons, leading to the degeneration of specialized receptor end organs and impairment of muscle innervation.

Animals↗
PubMed1999

Myelin formation by Schwann cells in the absence of beta4 integrin.

The interaction of the Schwann cell with its basal lamina has been hypothesized to be an important prerequisite for the formation of a myelin sheath in the peripheral nervous system. One possible player in this interaction is beta4 integrin; it is up-regulated during myelin formation and, in association with alpha6 integrin, can interact with particular components of the Schwann cell basal lamina. In order to characterize the functional roles of beta4 integrin during myelination, we investigated myelination in the absence of beta4 integrin, i.e., in peripheral nerve tissue from beta4 integrin-deficient mice. Because the mutants die within several hours after birth, we cultured dorsal root ganglia from neonatal mutants under conditions that promote myelination, quantified the myelin segments by immunofluorescence, and investigated the ultrastructure of the cultured myelin sheaths. In another approach, we quantified the few myelin sheaths that are detectable in femoral nerves of newborn animals. Based on both approaches, we conclude that myelination by Schwann cells can occur in the absence of beta4 integrin demonstrating that this Schwann cell component is dispensable for myelin formation in peripheral nerves.

Animals↗
PubMed1999

[Investigation of personal niche as basis of supportive psychotherapy].

According to the ecological theory of Willi 1996, people create and maintain their psychic wellbeing through constant shaping of their environment, i.e. setting up a personal niche. The personal niche in turn responds to, guides and challenges further personal development. This study explores what kind of solutions single patients with psychiatric invalidity can find in order to form their environment as a niche in which they may develop effectiveness and use it for their psychic regulation. 30 people were questioned with a semi-structured interview: they were patients of a psychiatric out-patient's clinic, living alone and psychiatrically invalidated (2/3 with schizophrenia of the residual type). The results were ranked after their increasing demands in a relational and in an activity inventory. The more relationship is based on mutuality expectations of others, personal disclosure and binding the more the subjects feel overstrained. The investigation of these inventories serve as a technical aid in supportive psychotherapy.

Adaptation, Psychological↗
PubMed1999

Diagnostic yield of bronchoscopy in histologically proven invasive pulmonary aspergillosis.

Invasive pulmonary aspergillosis (IPA) is a life-threatening infectious complication in neutropenic patients after high-dose chemotherapy or hematopoietic stem cell transplantation. Its diagnosis is mainly based on clinical symptoms, and radiological signs on thoracic CT scan. The value of bronchoscopy is controversial. We analyzed the diagnostic yield of bronchoscopy in 23 consecutive patients with histologically proven invasive pulmonary aspergillosis. In seven patients (30%) bronchoscopically obtained specimens were diagnostic for pulmonary fungal infection. Typical hyphae were detected by cytology in six patients and fungal cultures were positive in four cases. Patients with a positive bronchoscopic result presented more often with multiple changes on thoracic CT scan (71%; 5/7), but had received a lower median cumulative dose of amphotericine B (300 mg; 168-3010 mg) compared to patients with non-diagnostic bronchoscopy (25% multiple lesions (4/16); amphotericine dose 1100 mg, 260-2860 mg). The diagnostic yield of bronchoscopy was not associated with clinical symptoms or duration of neutropenia. Bronchoscopy allows the diagnosis of IPA in about one third of patients. Fungal cultures and cytological examination of intrabronchial specimens obtained during bronchoscopy have a high specificity, but its sensitivity is low. It is advisable to perform diagnostic bronchoscopy before starting antifungal therapy. Better diagnostic tools are urgently needed.

Adolescent↗
PubMed1998

[Chronic meningococcemia--a rare, but characteristic disease picture].

Chronic meningococcaemia is a rare clinical manifestation of invasive infection by Neisseria meningitidis. The clinical signs and symptoms are recurrent fever, skin rash, arthralgias and headache. This constellation is rather typical and may enable the clinician to establish the diagnosis. The clinical diagnosis is confirmed by the growth of Neisseria meningitidis in the blood culture. In addition, the clinical course under antibiotic treatment leads to a dramatic improvement within 24-48 hours. Positive cultures may be obtained by needle aspiration or skin biopsy. There are a few reports on patients with deficiency of late complement components or immunoglobulin deficiency. We report on two patients with the typical findings of chronic meningococcaemia.

Adult↗
PubMed1998

[Cutaneous diphtheria in returning vacationers--mirror of inappropriate vaccination practice?].

The causative agent for diphtheria is Corynebacterium diphtheriae, which is transmitted from person to person from the throat of carriers or from patients with active cutaneous diphtheria. The disease occurs in preexisting ulcers, but it may also appear on apparently normal skin. Although primary cutaneous diphtheria starts as a vesicle or pustule, most patients feature a reddish ulcer with undermined borders. The lesion is tender but hypesthesia develops after 2 weeks. The clinical diagnosis is based on the history of travelling in endemic regions and bacteriological studies. The current increase of diphtheria in the Western world is partly caused by rising tourism and a decline of booster vaccination in adults. After trauma with ulcerations of the skin we suggest to perform a booster vaccination not only for tetanus but also for diphtheria. In addition, persons travelling to endemic regions should receive a booster vaccination for tetanus and diphtheria, which is available as a combined preparation.

Adult↗
PubMed1998

Role of rifampin for treatment of orthopedic implant-related staphylococcal infections: a randomized controlled trial. Foreign-Body Infection (FBI) Study Group.

CONTEXT: Rifampin-containing regimens are able to cure staphylococcal implant-related infections based on in vitro and in vivo observations. However, this evidence has not been proven by a controlled clinical trial. OBJECTIVE: To evaluate the clinical efficacy of a rifampin combination in staphylococcal infections associated with stable orthopedic devices. DESIGN: A randomized, placebo-controlled, double-blind trial conducted from 1992 through 1997. SETTING: Two infectious disease services in tertiary care centers in collaboration with 5 orthopedic surgeons in Switzerland. PATIENTS: A total of 33 patients with culture-proven staphylococcal infection associated with stable orthopedic implants and with a short duration of symptoms of infection (exclusion limit <1 year; actual experience 0-21 days). INTERVENTION: Initial debridement and 2-week intravenous course of flucloxacillin or vancomycin with rifampin or placebo, followed by either ciprofloxacin-rifampin or ciprofloxacin-placebo long-term therapy. MAIN OUTCOME MEASURES: Cure was defined as (1) lack of clinical signs and symptoms of infection, (2) C-reactive protein level less than 5 mg/L, and (3) absence of radiological signs of loosening or infection at the final follow-up visit at 24 months. Failure was defined as (1) persisting clinical and/or laboratory signs of infection or (2) persisting or new isolation of the initial microorganism. RESULTS: A total of 18 patients were allocated to ciprofloxacin-rifampin and 15 patients to the ciprofloxacin-placebo combination. Twenty-four patients fully completed the trial with a follow-up of 35 and 33 months. The cure rate was 12 (100%) of 12 in the ciprofloxacin-rifampin group compared with 7 (58%) of 12 in the ciprofloxacin-placebo group (P=.02). Nine of 33 patients dropped out due to adverse events (n=6), noncompliance (n=1), or protocol violation (n=2). Seven of the 9 patients who dropped out were subsequently treated with rifampin combinations, and 5 of them were cured without removal of the device. CONCLUSION: Among patients with stable implants, short duration of infection, and initial debridement, patients able to tolerate long-term (3-6 months) therapy with rifampin-ciprofloxacin experienced cure of the infection without removal of the implant.

Aged↗
PubMed1998

[Pulmonary tuberculosis with resistance to 4 antitubercular drugs].

A 32-year-old immigrant from Pakistan was admitted to our hospital with cavernous pulmonary tuberculosis. He gave a history of several 1 to 2-months courses of antimycobacterial treatment administered earlier in Pakistan. We initiated combined therapy including isoniazid, rifampin, pyrazinamide, and ethambutol. Subsequently, results of susceptibility testing from M. tuberculosis-complex strains isolated before the onset of treatment documented the presence of resistance against both isoniazid and rifampin which may have been primary or acquired drug resistances. During the course of treatment, two additional resistances to pyrazinamide and ethambutol developed which were probably due to the initial therapy with only two active antimycobacterial agents. The emergence of multidrug-resistant strains of M. tuberculosis complex is a world-wide problem. Our case indicates that multiresistance must be considered in every patient presenting with tuberculosis. If there is a strong suspicion of multidrug-resistant tuberculosis, initial treatment with a combination of 5-6 antimycobacterial agents seems advisable until the results of susceptibility testing become available.

Adult↗
PubMed1998

Cutaneous manifestations of Paecilomyces lilacinus infection induced by a contaminated skin lotion in patients who are severely immunosuppressed.

BACKGROUND: New opportunistic fungal infections cause significant morbidity and death in patients who are severely immunocompromised. Cutaneous lesions may be the first clinical manifestation and give the clue to early diagnosis. OBJECTIVE: The purpose of this study was to describe the clinical and histologic manifestations of Paecilomyces lilacinus infection in patients who are severely immunosuppressed. METHODS: Within a 3-month period, we observed 5 patients with allogenic bone marrow transplantation and 4 patients with aplasia after chemotherapy for hematologic malignancies who developed skin eruptions caused by invasive P lilacinus. RESULTS: The skin lesions began in 7 cases during or shortly after recovery of pancytopenia. Most of the skin lesions were located on the lower extremities. The cutaneous manifestations were highly variable including erythematous macules, nodules, pustules, vesicular lesions, and necrotic crusts. In 3 biopsy specimens, histologic examination revealed hyphae in periodic acid-Schiff-stained sections. In all patients P lilacinus was isolated from skin tissue samples. P lilacinus was identified from all lesions either by skin biopsy or needle aspiration from clinically evident lesions. In 3 additional cases, the patient's hands were colonized without skin lesions. The source of the epidemic outbreak was finally traced down to several contaminated lots of a topical moisturizing agent. Two patients died; one patient had septic lesions in the eye and kidney as the result of P lilacinus. CONCLUSION: Clinical and histologic findings of P lilacinus infection with cutaneous manifestations in patients who are severely immunosuppressed are summarized. P lilacinus is resistant to all systemic antimycotics available, and in general, recovery of immunosuppression is necessary to eradicate the mold. Contaminated topical dermatologic agents should be included in the differential diagnosis as a source for severe epidemic cutaneous manifestations of fungal infection in patients who are severely immunosuppressed. This fact implies that additional safety guidelines are necessary for topical dermatologic agents used for patients who are severely immunosuppressed.

Adolescent↗