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Biomedical subjects

H Gerber

Publications and source records attributed to H Gerber.

At least 37 records · Page 2Linked to original sources
PubMed2000

Comparison of two methods for the detection of urinary iodine used in epidemiological studies.

Two methods for the determination of iodine in urine or serum based on the Sandell-Kolthoff reaction were compared. The first was an autoanalyser method (AAII, Technicon) where the mineralisation takes place in a continuous flow manner. This procedure was used at the Department of Clinical Chemistry of the University Hospital of Berne (Switzerland) from 1968 until 1993. The second method was evaluated and adapted in our own laboratory. Each sample and the iodate-standards are mineralised in a Pyrex glass tube and the decolorisation reaction takes place in a 96-well-microtiter plate which was read by a PC-controlled photometer at 405 nm. This method, with a detection limit of 0.1 micromol/l showed good analytical recovery (90 to 110%) and a low imprecision (intra-assay coefficient of variation (CV) of 5% and an inter-assay CV of 7.5%). In contrast to the autoanalyser method, the microtiter plate-method is suitable both for series up to 24 samples (3-fold) and for single samples. A comparison of 87 samples in the range of 0.1 to 60 micromol/l which were measured with both Sandell-Kolthoff based methods showed no obvious discrepancy. These two methods showed a good agreement for the determination of urinary iodine. This guarantees that the results of earlier epidemiological studies can be compared with recent studies performed in our and many other laboratories.

Humans↗
PubMed2000

Age- and gender-dependent urinary iodine concentrations in an area-covering population sample from the Bernese region in Switzerland.

OBJECTIVE: Before a scheduled increase of salt iodide content up to 20 p.p.m. in Switzerland, urinary iodine concentration (UIC, microg/l) of a randomly selected, area-covering, age-stratified population subgroup was sampled in spring 1997. In contrast to former published studies on UIC, we minimized biases by age, gender, rural/urban, socio-economic and cultural influences. METHODS: We contacted 750 households in the Bernese region using random telephone numbers. Per household, one proband selected by play dice collected a spot urine sample. We defined seven age categories: infants, children, adolescents, adults I-III and seniors, aged 0-5, 6-12, 13-20, 21-35, 36-50, 51-65 and >65 years respectively. Randomized UIC data were compared with WHO criteria of iodine deficiency (ID) and previous non-randomized, age-dependent Swiss UIC data. To recruit a perfect random group of volunteers proved difficult, as study participation of adolescent and male populations was somewhat lower than that of elder and female (P<0.005) populations respectively. Study participation of inhabitants of rural and suburban regions was comparable (P=0.139). Out of 413 obtained urine spots, 412 (55%) were analyzed statistically (58% women, 42% men, P<0.005). RESULTS: Ninety per cent of all UIC values ranged between 25 and 200 microg/l. Median UIC showed mild ID (94 microg/l). UIC varied significantly between age categories (P=0. 0006). Women had lower UIC than men (P=0.014). Infants had no ID. Women in child-bearing age (13-35 years), adults II, adults III and seniors had mild ID. Compared with recommended supplies of 150 and 200 microg I/day in children and male adolescents respectively, we consider their UIC (110 and 144 microg/l) as at least borderline deficient. Absolute UIC was lowest in seniors. Probands from rural/suburban households had similar UICs. Our UIC data were comparable to published ones. CONCLUSIONS: Despite long-term national efforts with iodized salt (15 p.p.m. in 1997), mild ID still prevailed in Bern in spring 1997, with rare extreme UIC values. Mild ID with women in child-bearing age (and probably also with children and male adolescents) was a serious concern, as goiter growth with puberty or pregnancy might be the consequence. Mild ID in adults and seniors might be due to restricted NaCl intake. Results of our randomly selected subgroup from a 650 000 population show that age- and gender-dependency are important when comparing our collected data with published UIC data. This fact must be considered with non-randomly selected population subgroups.

Adolescent↗
PubMed1999

Sulfidoleukotriene generation from peripheral blood leukocytes of horses affected with insect bite dermal hypersensitivity.

Sulfidoleukotrienes (sLT) generated in vitro after incubation of equine peripheral blood leukocytes (PBL) with different inducing agents were determined in 18 healthy and 16 insect bite dermal hypersensitivity (IDH)-affected horses. PBL from these 32 horses were stimulated with Concanavalin A, Parascaris equorum, Culicoides nubeculosus and Simulium extracts, and with a six-Grass mix. The cells of all but four horses generated sLT after incubation with Concanavalin A; these four horses did also not produce sLT with the other inducing agents. Of the 28 remaining horses (12 affected with IDH and 16 healthy), all but three generated sLT with the P. equorum extract. The six-Grass mix did not induce sLT production in any of the tested horses. sLT generation with Concanavalin A and Parascaris was statistically not different between IDH-affected and healthy horses. PBL of the diseased horses, however, produced significantly more sLT with the Culicoides (p < 0.01) and Simulium (p < 0.05) extracts than those of the healthy animals. Additionally, sLT generation with the Culicoides extract was measured at different times of the year in one IDH-affected animal and remained high even in winter, when the horse was asymptomatic. sLT and histamine release were determined in 10 horses in parallel. Positive correlations of 0.81 and 0.82 for Concanavalin A and Parascaris (p < 0.01 and p < 0.05, respectively), and of 0.95 and 0.94 for Culicoides and Simulium (p < 0.01) were found between sLT and histamine release. These results indicate that, alike in humans, sLT are released in vitro from equine basophils along with histamine in response to various stimuli and that immediate type hypersensitivity reactions to Culicoides and Simulium are often involved in the pathogenesis of IDH. Thus, sLT generation from equine basophils offers an in vitro diagnostic tool for IDH even in sensitised but asymptomatic horses.

Animals↗
PubMed1999

Capillary electrophoresis in clinical and forensic analysis: recent advances and breakthrough to routine applications.

This paper is a comprehensive review article on capillary electrophoresis (CE) in clinical and forensic analysis. It is based upon the literature of 1997 and 1998, presents CE examples in major fields of application, and provides an overview of the key achievements encountered, including those associated with the analysis of drugs, serum proteins, hemoglobin variants, and nucleic acids. For CE in clinical and forensic analysis, the past two years witnessed a breakthrough to routine applications. As most coauthors of this review are associated with diagnostic or forensic laboratories now using CE on a routine basis, this review also contains data from routine applications in drug, protein, and DNA analysis. With the first-hand experience of providing analytical service under stringent quality control conditions, aspects of quality assurance, assay specifications for clinical and forensic CE and the pros and cons of this maturing, cost-and pollution-controlled age technology are also discussed.

Electrophoresis, Capillary↗
PubMed1999

Spondylodiscitis caused by viridans streptococci: three cases and a review of the literature.

Three cases of spondylodiscitis caused by viridans streptococci were observed within the course of 1 month. Although streptococci have been reported as the third most frequent cause of spondylodiscitis after staphylococci and gram-negative bacteria, alpha-haemolytic streptococci are rarely seen. The three patients presented with symptoms of low back pain; they felt well and did not have a fever or chills. Laboratory examinations revealed inflammation. Further examinations such as scintigraphy, computed tomography or magnetic resonance imaging were done. Bacteriological diagnosis was established by blood cultures in two cases and by needle biopsy of the disco-vertebral space in one. In one patient endocarditis was also documented. Because the prevalence of endocarditis was found to be higher in our cases of spondylodiscitis due to Streptococcus viridans than for other bacteria, the exclusion of this diagnosis must be pursued aggressively. These observations lead us to question if the spectrum of bacteria causing spondylodiscitis is undergoing a change. an aetiological agent could be isolated in 1168 patients (85.4%): in 48% a staphylococcus, in 28% a gram-negative bacterium and in only 10% a streptococcus. There were two cases of viridans streptococci (0.2%). These two cases together with other single case reports [14-22] account for 15 cases of spondylodiscitis due to alpha-haemolytic streptococci. Differentiation of the organisms to the species level was accomplished in six cases: S. mitis (3), S. sanguis (2) and S. anginosus (1). Although a multitude of organisms, bacterial as well as fungal, causing spondylodiscitis has been reported in recent years, almost all were single cases [23-42]. The unusual observation of three cases of spondylodiscitis due to alpha-haemolytic streptococci within 1 month prompted us to review the clinical and laboratory findings and to compare these cases with those caused by Staphylococcus aureus.

Adult↗
PubMed1999

Growth hormone corrects acidosis-induced renal nitrogen wasting and renal phosphate depletion and attenuates renal magnesium wasting in humans.

We have shown previously that chronic hyperchloremic metabolic acidosis (CMA) induces severe negative nitrogen balance and renal phosphate depletion and decreases serum insulin-like growth factor-1 (IGF-1) in association with growth hormone (GH) insensitivity in humans. The present study investigated whether acidosis-induced renal nitrogen wasting and renal phosphate depletion are mediated by GH insensitivity/low IGF-1 and thereby responsive to GH treatment. The effects of GH on acidosis-induced changes in divalent cation metabolism and acidosis-induced hypothyroidism were also investigated. CMA (delta[HCO3], -10.5 mmol/L) was induced in six healthy male subjects ingesting 4.2 mmol NH4Cl/kg body weight [BW]/d for 7 days. Recombinant human GH (0.1 U/kg BW/12 h subcutaneously) was administered for 7 days while acid feeding was continued. GH increased serum IGF-1 from 22.1 +/- 1.4 to 87 +/- 8.4 nmol/L (control level, 36.4 +/- 2.2). GH decreased urinary nitrogen excretion, resulting in a cumulative nitrogen retention of 2,404 mmol, thereby correcting the acidosis-induced cumulative increase in nitrogen excretion (2,506 mmol) despite continued acid feeding. GH attenuated the acidosis-induced hyperphosphaturia (cumulative phosphate retention, 91 mmol) and corrected the hypophosphatemia. GH did not affect acidosis-induced ionized hypercalcemia, but further exacerbated acidosis-induced hypercalciuria (cumulative loss, 27.3 mmol). GH significantly further increased serum 1,25-dihydroxyvitamin D (1,25(OH)2D) and further decreased intact PTH (from 10 +/- 1 to 6 +/- 1 pg/mL). Acidosis also induced hypomagnesemia and hypermagnesuria (cumulative loss, 9.4 mmol, ie, renal magnesium wasting), a novel finding, which was significantly attenuated by GH (cumulative retention, 5.0 mmol). In conclusion, GH corrected acidosis-induced renal nitrogen wasting, which may be caused, at least in part, by decreased IGF-1 levels. GH further increased serum 1,25(OH)2D and the systemic calcium load, which account for the suppression of parathyroid hormone (PTH) despite renal PO4 retention and correction of hypophosphatemia. GH attenuated acidosis-induced renal magnesium wasting.

Acidosis, Renal Tubular↗
PubMed1999

Colloidal aggregates of insoluble inclusions in human goiters.

To shed some light on the physicochemical properties of the thyroid follicular colloid, we have screened retrospectively the autoradiographs of 60 human nodular goiters labeled 17 h preoperatively with 100 microCi 125I for evidence of colloid compartmentalization. In 87% (52/60) of all goiters examined, sporadic or multiple colloidal inclusions ('colloid stones') not mixing with newly labeled Tg were detected. The detailed analysis of 17 goiters revealed a mean incidence of 0.09+/-0.11 'colloid stones' of variable size per follicle ranging from 0.02+/-0.01 (10) to 0.43+/-0.09 (5) (mean values +/- S.D., number of sections examined in brackets). In this study we did not find a clear-cut association of incidence of 'colloid stones' with sex, age or nosologic group (hyperthyroid, preclinically hyperthyroid, euthyroid). The existence of different colloidal compartments as demonstrated in this and other studies is of considerable importance for thyroid function, interpretation of iodine kinetics, and studies on the role of iodine on growth and function of the thyrocytes. Different thyroidal iodine compartments could well be of functional relevance, for example in the adaptation of thyroid hormone secretion to antithyroid drugs or in severe and prolonged iodine deficiency, when very slow compartments become an important source of minimal quantities of iodine and thyroid hormone. 'Colloid stones', for example, may well explain the repeatedly observed, surprisingly large total iodine store in human endemic goiters, even in the presence of severe iodine deficiency. It is evident that the existence of multiple iodine compartments and, in particular, of particulate slow-turnover pools complicates the interpretation of total glandular iodine measurements with modern techniques such as X-ray fluorescence and positron emission tomography.

Adult↗
PubMed1999

Histological findings after long-term infusion of intrathecal ketamine for chronic pain: a case report.

Ketamine, a selective, noncompetitive N-methyl-D-aspartate (NMDA)-receptor antagonist, is able to alter pain perception at the spinal level. Little clinical data exist on the intrathecal and epidural use of ketamine in chronic pain. Histopathologic findings after intrathecal injection of ketamine with and without preservatives are rarely reported. This outcome was evaluated in a 72-year-old woman with abdominal pain due to cancer who was treated with the intrathecal application of bupivacaine, clonidine, and morphine. We reached satisfactory pain relief with the addition of ketamine to the mixture for 7 days. On postmortem, focal lymphocytic vasculitis close to the catheter injection site was found. This finding has not been described previously after long-term application of ketamine intrathecally. The intrathecal infusion of ketamine with preservative, or the mixture of ketamine, clonidine, morphine, and bupivacaine resulted in isolated lymphocytic vasculitis of the spinal cord and leptomeninges without any clinical signs of neurological deficit.

Aged↗
PubMed1999

Detection of fluid volume absorption by end-tidal alcohol monitoring in patients undergoing endoscopic renal pelvic surgery.

STUDY OBJECTIVE: To determine the risk of relevant fluid absorption (calculated volume above 500 ml) during endoscopic procedures of the renal pelvis. DESIGN: Prospective clinical investigation with implementation of statistical process control tools (SPC). SETTING: Nonuniversity teaching hospital. PATIENTS: 62 consecutive ASA physical status I and II patients scheduled for endoscopic renal pelvic surgery with general anesthesia. INTERVENTIONS: Intraoperative measurement of breath alcohol for detection of fluid absorption. Irrigation fluid (0.9% saline) with 1% alcohol for tracing the irrigation fluid. MEASUREMENTS AND MAIN RESULTS: Calculation of the amount of fluid absorbed using breath alcohol values. Process variability (numbers of patients with relevant fluid absorption) defined by SPC. The prevalence of fluid absorption in endoscopic renal pelvic surgery was 6%. Peak fluid absorption during a vascular route was detected by the monitoring. Monitoring was easily introduced into routine clinical practice. No relevant side effects due to the monitoring were seen in patients with relevant fluid absorption. There was no mortality, but two patients with detected severe fluid overload were admitted to the intensive care unit for treatment. CONCLUSION: Breath alcohol levels during general anesthesia for endoscopic renal pelvic surgery were technically simple to measure. Our results show the predictive value of alcohol monitoring, which has been previously demonstrated only for transurethral prostatectomy. The prevalence of relevant fluid absorption was 6% compared to 13% during transurethral resection of the prostate.

Absorption↗
PubMed1999

[Therapy of amiodarone-induced thyrotoxicosis and hypothyroidism].

Pathogenesis, diagnostic procedures and therapy of amiodarone-induced thyrotoxicosis (AIT) and hypothyroidism (AIH) are briefly discussed. Diagnosis of AIT and AIT is based on the classical signs and symptoms of thyroid dysfunction, although oligosymptomatic cases may occur, and on laboratory tests such as TSH, fT4 und fT3. In AIT, radioiodine therapy usually is no option due to the high iodine content of amiodarone. Besides withdrawal of amiodarone, medical and surgical treatment remain the only modalities. If arrhythmia can be controlled by an alternative treatment, amiodarone should be discontinued although this will not immediately restore normal thyroid function. For medical treatment, thionamides, perchlorate (not available in Switzerland), steroids (mainly for type II and mixed forms of AIT) and lithium (only for severe cases) are available. Surgery is a valid therapeutical option for severe forms of AIT which cannot be controlled adequately by medical treatment. The main advantage of surgical therapy of AIT is the rapid correction of thyrotoxicosis combined with the possibility to continue amiodarone, if it is necessary and effective. With AIH, amiodarone does not have to be stopped, if indicated and effective, and L-thyroxine is the therapy of choice.

Algorithms↗
PubMed1999

Iodine supply in different geographical areas of Switzerland: comparison between rural and urban populations in the Berne and the Ticino regions.

OBJECTIVE: We studied the question of possible regional differences of iodine intake in the population of rural and urban areas north and south of the Alps. DESIGN: Transversal study. SETTING: Six different regions from northern (Canton Berne) and southern Switzerland (Canton Ticino). SUBJECTS: For each region 30 individuals were studied. RESULTS: While significant differences of urinary iodine between some regions were found (range from 79 microg iodine/g creatinine in Chiasso to 130 microg iodine/g creatinine in the Maggia Valley), no significant differences between rural and urban populations of north and south of Switzerland were observed. Mild iodine deficiency affected 35%, moderate iodine deficiency 12% and severe iodine deficiency 0.6% of the total population investigated. CONCLUSIONS: 49% of this population showed at least mild or moderate iodine deficiency. The mean urinary iodine was just at the lower recommended limits. Significant differences were found between individual regions (such as Chiasso and the Valley of Maggia), but not generally between rural and urban areas in the north and south of the Alps.

Creatine↗
PubMed1999

Intermediate stages in monocyte-macrophage differentiation modulate phenotype and susceptibility to virus infection.

The kinetics of monocyte-macrophage differentiation was analysed using two Swine Workshop Cluster (SWC) CD molecules: SWC1 and SWC9. Myeloid cells were selected by labelling for the common myeloid antigen, SWC3. Confirmation of macrophage identification used acid phosphatase and phagocytosis activities. During differentiation, SWC1 was gradually lost. SWC9 was absent on monocytes but up-regulated early. Consequently, monocytes were SWC1+ SWC9- and macrophages were SWC1- SWC9+. An additional, intermediate, cell population was identified as SWC1+ SWC9+. Size and granularity characteristics mirrored the monocyte, macrophage and intermediate-cell phenotypes. Overall, SWC9 up-regulation was central in macrophage differentiation and dependent on plasma factors. The concomitant loss of SWC1 was independent of these factors, but always associated with mature macrophages. Upon up-regulation of SWC9, the SWC1+ SWC9+ intermediate monocytic cells became susceptible to African swine fever virus infection. These results demonstrate the heterogeneity of monocytic cell differentiation and the importance of these characteristics for interaction with monocytotropic viruses.

African Swine Fever↗
PubMed1999

Phenotypic analysis of bronchoalveolar lavage fluid lymphocytes in horses with chronic pulmonary disease.

A panel of specific antibodies against CD3, CD4, CD5, CD8, MHC I and II was used in single and two colour flow cytometry to define T cell subpopulations in bronchoalveolar lavage fluid of horses affected with chronic obstructive pulmonary disease and of healthy controls. According to the results of the clinical examination including bronchoscopy and cytology of the tracheal aspirate the horses were divided into four groups (healthy, subclinically to mildly affected; moderately affected, and severely affected). All groups of horses had a similar percentage of CD3+ cells in the BALF. Compared to controls, severely affected horses had a significantly increased number of CD4+ cells in the BALF, but a similar percentage of CD4+ cells whereas mildly and moderately affected horses had a decreased percentage. The percentage and number of CD8+ cells and the percentage of CD8+/MHCII+ cells in the BALF was found to be higher than normal and varied according to the disease state. This novel finding raises the possibility that not only the CD4+ cells but also the CD8+ cells are involved in the pathogenesis of COPD. The percentage and the number of CD8+ cells in BALF might be of diagnostic value to detect subclinical to mild cases of COPD.

Animals↗
PubMed1999

A centrifugal particle concentrator for use in inhalation toxicology.

Epidemiologic studies have provided strong evidence that episodic exposure to ambient particulate matter is associated with increases in morbidity and mortality. These adverse effects have been demonstrated at concentrations far below the National Ambient Air Quality Standard (NAAQS), and thus, the biological plausibility of these effects has been questioned. For the purpose of exposing test animals to relevant and reproducible exposure concentrations of ambient particulate matter (PM), we have developed a simple and inexpensive concentrator system that can concentrate ambient particles 10-fold. A high-volume blower is used to deliver ambient air to the inlet manifold of a centrifugal concentrator and the entrained particles travel along a concentric annulus formed by a stationary solid outer cylinder and a porous inner cylinder rotating at high speed (up to 12,500 rpm). Suction applied at one end of the porous shaft causes the dispersion medium (air) to pass through the porous cylinder and into the shaft. Since the rotational velocity of airborne particles is comparable to that of the rotating cylinder near its surface, the particles move radially outward due to the centrifugal force, in addition to their motion laterally along the cylinder and inward due to the suction of air into the rotating porous cylinder. The particles reach their highest concentration near the outlet manifold, where they enter the exposure chamber under positive pressure ( approximately 0.4 cm H2O). Except for coarse particle loss due to impaction and diffusional loss of ultrafine particles in the concentrator, the increase in particle concentration is the ratio of the flow rates for the inlet air and the air delivered to the exposure chamber. We have used the centrifugal concentrator to deliver concentrated ambient urban PM to a nose-only exposure chamber and examined the concentrating effect across ambient particle sizes.

Air↗
PubMed1999

The effects of in vitro hemodilution with gelatin, hydroxyethyl starch, and lactated Ringer's solution on markers of coagulation: an analysis using SONOCLOT.

UNLABELLED: Blood-saving strategies have recently been established to avoid allogeneic transfusion during surgery or after trauma. This includes an expanding use of crystalloids and colloids. These solutions interfere with coagulation systems, but quantitative measurements are still lacking. The SONOCLOT (Sienco Company, Morrison, CO) analysis (SCT), a viscoelastic test, measures clot formation and includes information on the cellular, as well as the plasmatic coagulation, system. To quantify hemodilutional effects on in vitro coagulation, we studied gelatin (G), hydroxyethyl starch 6% (HES; molecular weight 450,000), and lactated Ringer's solution (RL) in 33% and 66% dilutions measuring routines laboratory and SCT variables. Hemodilution with RL tended to increase in vitro coagulability. Among the tested colloids, G had the least impact on markers of coagulation. G33% did not differ significantly from the undiluted control group. HES had the largest impact on markers of coagulation compared with G and RL. In conclusion, SCT provides a fast and easy to perform bedside test to quantify in vitro hemodilution. IMPLICATIONS: The effects of progressive hemodilution on coagulation are difficult to measure. SONOCLOT analyses provide an easy to perform test with fast information on cellular and plasmatic coagulation properties. Among colloids, hydroxyethyl starch has the largest impact on markers of coagulation compared with gelatin or lactated Ringer's solution.

Adult↗
PubMed1999

Three-dimensional video analysis of facial movements: a new method to assess the quantity and quality of the smile.

The results of neuromuscular reconstructions of the paralyzed face are difficult to assess. Very sophisticated methods are necessary to measure the motor deficits of facial paralysis or the functional recovery in the face. The aim of this development was a relatively simple system for data acquisition, which is easy to handle and which makes it relatively cheap to delegate data acquisition to centers all over the world, which will not be able to derive a data analysis on their own, but will send their data to a center with specialized equipment. A complex mirror system was developed to get three different views of the face at the same time on the video screen. At each investigation, a digital video is taken from a calibration grid and from standardized facial movements of the patient. Secondary analysis of the digital videofilm is made possible at any time later on by the support of a computer program, which calculates distances and movements three-dimensionally from the frontal image and the right and left mirror images. Pathologies of the mimic movements can be identified as well as improvements after surgical procedures by this system. The significant advantage is the possibility to watch the same movement on the video which is under study and to apply any kind of study later on. Taking the video needs only a few minutes, and fatigue of the patient's mimic system is prevented. Measurements usually at the endpoints of the movements give excellent information on the quantity of the movement or the degree of the facial palsy, whereas the video itself is very informative regarding the quality of the smile. Specific computer software was developed for standardized three-dimensional analysis of the video-documented facial movements and for data presentation. There are options like two-dimensional graphs of single moving points in the face or three-dimensional graphs of the movements of all measured points at the same time during a standardized facial movement. By a comparison of the right- and left-sided alterations of specific distances between two points during the facial movements, the degree of normal symmetry or pathologic asymmetry is quantified. This system is more suitable for detailed scientific multicenter studies than any other system previously established. A very sensitive instrument for exact evaluation of mimic function is now available.

Calibration↗