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Mucin release and calcium fluxes in isolated rat submandibular acini.

A method is described for preparing isolated rat submandibular acini by collagenase digestion followed by mechanical dispersion. As assessed by Trypan Blue exclusion, phase contrast microscopy, ATP content and release of mucins and lactate dehydrogenase, the acini are morphologically and functionally intact. Secretory function of isolated acini was similar to that of intact tissue in terms of time-course, dose dependence and degree of stimulation of mucin release by adrenergic secretagogues. Mucin release was increased to the same extent (approx. 3-4-fold) by either isoproterenol or noradrenaline at a maximally effective concentration (10 microM). Stimulation of mucin release by isoproterenol (10 microM), noradrenaline (10 microM) or adrenaline (10 microM) was inhibited by propranolol (30 microM) but not by phentolamine (30 microM). Isoproterenol (10 microM) increased both 45Ca2+ uptake and efflux from the acini, which was shown to represent a net release of calcium. However, there was a delay (approx. 10 min) in onset of stimulation of 45Ca2+ mobilization which was not apparent in isoproterenol stimulation of mucin release. Our results indicate that increases in intracellular calcium mobilization in response to a beta-adrenergic secretagogue do not trigger mucin secretion from rat submandibular acini.

Animals↗

Red blood cell and platelet induced differentiation of endothelial cells into capillary-like structure.

We cultivated endothelial cells of human umbilical vein origin in the presence of red blood cells and platelet-rich plasma, and observed the phenomena which occurred in the petri dish under phase contrast microscopy. Many small particles were observed after an overnight incubation. We washed the dish two times, then added thrombin to the dish. The network of thread-like strands appeared within 10 to 20 minutes of the addition, and at the same time the small particles adhered on the surface of the strands, swelled and fused gradually to cover the surface of the strands completely. Within 30 to 60 minutes the network of the strands changed into a capillary-like structure. These phenomena were not observed if we omitted red blood cells or platelet-rich plasma. Studies by transmission electron microscopy revealed that the inner surface of the lumen of the structure was covered with cells. The cells isolated from the lumen by trypsin grew to confluence in the conventional culture medium, and showed vWF antigen on their surface. These observations indicated that the method described is useful for in vitro study of angiogenesis.

Blood Platelets↗

Megakaryocyte maturation in long-term marrow culture.

Evidence has been sought for megakaryocyte maturation in long-term cultures of mouse bone marrow. Cultures up to 14 weeks of age were examined for the presence of megakaryocytes with processes, that is, resembling the morphological appearance seen in vivo prior to platelet liberation. Such cells were found floating just above the adherent stromal layer using low magnification phase contrast microscopy. It was rare to observe as many as 20 of these cells per 25-cm2 flask. At higher magnification, processes were seen to be attenuated with constrictions at intervals along their length. Time-lapse photography was used to follow the development and behavior of the processes. Direct evidence of rupture was very rare; generally the megakaryocytes retracted their processes within 48 h. Careful searching of cultures occasionally revealed the presence of several process fragments, and sometimes individual platelets were found. Ultrastructurally, the processes were seen to contain organelles that are usually associated with platelets. The observations applied to both Dexter and Whitlock-Witte cultures. It is concluded that maturation of megakaryocytes occurs in long-term marrow culture to the point where platelet release appears imminent. Final rupture is rare and may require shearing forces, which in vivo would be provided by blood flow.

Animals↗

Early events in the development of neuronal polarity in vitro are altered by ethanol.

Among the neuropathological effects of prenatal exposure to ethanol is the disruption of neuromorphogenesis. The effects of ethanol on early events in the development of axons and dendrites were studied using cultured embryonic rat hippocampal neurons, which develop in vitro in a stereotypical sequence of events that mimics their development in vivo. During the first 24 hr in culture, hippocampal neurons attach to the substrate and develop into one of three stages identified by phase-contrast microscopy: (i) neurons having lamellipodia and no processes (stage 1); (ii) neurons developing minor processes (<40 microm) that subsequently become the cell's axon or dendrites (stage 2); or (iii) polarized neurons with at least one axon (process with length > or =40 microm) (stage 3). Exposure to ethanol (300 mg/dl or 800 mg/dl) in the culture medium resulted in an increase in both the number of minor processes per neuron and the number of stage 3 neurons having more than the typical single axon. In addition, ethanol exposure significantly altered the proportion of neurons in the three early stages of development at 18 to 24 hr in vitro, without affecting overall neuron survival. With ethanol, there was a smaller proportion of neurons in the first stage of development, and a greater proportion of polarized stage 3 neurons. These findings suggest that ethanol alters the normal establishment of neuronal polarity, disrupting mechanisms that ensure the formation of the appropriate number of processes and that regulate the timing of process outgrowth.

Animals↗

The isolation and characterization of nuclear ghosts from cultured HeLa cells.

Macromolecular complexes, which appear as ghosts when viewed by phase contrast microscopy, have been isolated from the nuclei of HeLa cells grown in culture. The preparation of these ghosts involves a detergent wash which removes the unit membranes of the nuclear envelop structure but leaves intact both the nuclear pores and the dense structure conferring nuclear margins (possibly the dense lamella). Detergent-washed nuclei are subsequently treated with 0.5 M MgCl2 and fractionated on continuous sucrose gradients containing 0.5 M MgCl2. The ghosts are recovered as a sharp band at an apparent sucrose density of 47-52% and consist of 72% protein, 10% phospholipid, 14% DNA, And 4% RNA. The release of the majority of intranuclear components is indicated by the large loss of nuclear DNA (95%), RNA (71%), and protein (87%) contrasted to the small loss of phospholipid (27%) druing the conversion of detergent washed nuclei to isolated ghosts. Sodium dodecyl sulfate-polyacrylamide gel patterns of the ghost proteins consist of two major bands with approximate molecular weights of 20,000 and 35,000. The isolation of ghosts with a similar density and protein composition from nondetergent-washed nuclei indicates that the ghost is not an artifact induced by the detergent treatment. The absence of cytoplasmic contamination in the preparations of detergent washed nuclei and nuclear ghosts was demonstrated by chemical, enzymatic, and electron microscope studies. We suggest that the isolated ghosts represent a structural macromolecular complex which underlies and is probably attached to the inner nuclear membrane of intact nuclei. The possible additional presence of intranuclear network proteins has not been excluded.

Amino Acids↗

Mast cell chymase induces conjunctival epithelial cell apoptosis by a mechanism involving degradation of fibronectin.

PURPOSE: To determine the mechanism of conjunctival epithelial injury in vernal keratoconjunctivitis, we investigated the effects of human chymase on conjunctival epithelial cells in vitro. METHODS: Human conjunctival epithelial cells were incubated with human chymase for 24 or 48 hr at levels of activity that were likely to exist in the tear fluid of patients with vernal keratoconjunctivitis. Morphologic changes of the cells were observed by phase contrast microscopy. To determine the number of detached cells, we used an automated cell counter, while apoptotic cells were quantitated by flow cytometry. The level of soluble fibronectin in conditioned medium was measured by ELISA. RESULTS: Most of the cells in the incubation with chymase were detached by 24 hr. However, chymase-mediated apoptosis was a slower process and was only detected after incubation of cells with chymase for 36 to 48 hr. Both cell detachment and apoptosis were blocked when cells were incubated in fibronectin-coated plates. The increase of soluble fibronectin was dependent on the amount of chymase added and the exposure time. A caspase inhibitor (antiapoptotic agent) rescued cells from apoptosis but did not prevent cell detachment. These results indicate that chymase-induced apoptosis of conjunctival epithelial cells represents anoikis, which is a slowly occurring apoptotic process induced by lack of adhesion to an extracellular matrix. CONCLUSIONS: Human mast cell chymase caused conjunctival epithelial cell detachment by degrading fibronectin, and this led to secondary apoptosis.

Apoptosis↗

Is the red cell morphology really useful to detect the source of hematuria?

Morphological analysis of urinary red blood cells by phase-contrast microscopy to identify the source of bleeding was, and still is, widely used also as a starting point for workup. To evaluate the reliability of this approach, we studied 129 outpatients presenting with persistent isolated microhematuria; 31 subjects also had mild proteinuria (1 g/day), while 21 had pathological albumin levels. All patients were followed for a period of 6 years. During this time, 6 patients underwent renal biopsy for the onset of macrohematuria episodes and proteinuria of 2-3 g/day. Glomerular bleeding was identified in only 14.7% of the patients, despite the persistent microhematuria and the presence of proteinuria or microalbuminuria. The renal origin of the urinary erythrocytes correlated with histological findings in only 2 of 6 patients with dysmorphic erythrocytes who developed proteinuria (exceeding 1 g/day), and none with isomorphic erythrocytes showed urological abnormalities. These results challenge the validity and reliability of morphological analysis to identify the source of bleeding along the urinary tract.

Adult↗

A relevant in vitro eukaryotic live-cell system for the evaluation of plasmodial protein localization.

Understanding the functional genomics and proteomics of plasmodia underpins the development of new approaches to antimalarial chemotherapy. Although genome databanks (e.g. PlasmoDB) and biocomputing tools (e.g. PlasMit, PlasmoAP, PATS) are useful in providing a global albeit predictive view of the myriad of about 5000 genes, only 40% are annotated, with few cases of endorsed subcellular localizations of the corresponding proteins in animal models. Progress in plasmodial protein trafficking has been hampered by the lack of a simple yet reliable method for studying subcellular localization of plasmodial proteins. In this study, we have used a combination of fluorescent markers, organelle-specific probes, phase contrast microscopy, and confocal microscopy to locate a selection of signal peptides from 10 plasmodial proteins in CHO-K1 cells. These eukaryotic cells serve as an in vitro living system for studying the cellular destinations of four mitochondrial-targeted TCA cycle proteins (citrate synthase, CS; isocitrate dehydrogenase, ICDH; branched chain alpha-keto-acid dehydrogenase E1alpha subunit, BCKDH; succinate dehydrogenase flavoprotein-subunit, SDH), two nuclear-targeted proteins (histone deacetylase, HDAC; RNA polymerase, RPOL), two apicoplast-targeted proteins (pyruvate kinase 2, PK2; glutamate dehydrogenase, GDH), and two cytoplasmic resident proteins (malate dehydrogenase, MDH; glycerol kinase, GK). The respective localizations of these malarial proteins have complied with the selected molecular targets, viz. mitochondrial, nuclear and cytoplasmic. Interestingly, MDH that is widely known to be resident in eukaryotic mitochondria was found to be cytoplasmic, probably due to the absence of molecular target sequences. Since the localization of plasmodial proteins is central to the authentication of their pathophysiological roles, this experimental system will serve as a useful a priori approach.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗

Effects of prolactin on the morphology of cultured rat granulosa cells.

Morphological changes were correlated with biochemical data induced by prolactin (PRL) in cultured rat granulosa cells from large preovulatory follicles. Biochemical results indicated that PRL exerted a significant dose-dependent inhibition in gonadotrophin-induced secretion of progesterone and 17 beta-oestradiol. PRL alone failed to affect basal steroidogenic secretion. In parallel morphological experiments, using phase-contrast microscopy, untreated and 100 ng/ml PRL-treated cells appeared as a monolayer of flattened, fibroblast-like cells. Upon exposure to 0.4 IU/ml human chorionic gonadotrophin (hCG), aggregates of rounded, epithelioid-shaped cells were formed. The addition of PRL to hCG in the same doses minimized the changes induced by hCG. Similarly, electron microscopy of untreated and PRL-treated cultures revealed flat cells devoid of microvilli, with evenly dispersed microfilaments. The addition of hCG caused rounding of the cells and was accompanied by the appearance of microvilli and by pronounced steroid-producing organelles. Bundles of microfilaments were noted at the cell periphery. PRL added to hCG caused a reduction of the hCG effects, and the cell morphology was intermediate to that seen in untreated and hCG-treated cultures. The finding that PRL can prevent or minimize morphological changes caused by hCG in rat cultured granulosa cells correlates with the biochemical changes induced by PRL, and supports the concept that PRL is a modulator of gonadotrophic action in the ovary.

Animals↗

Permeability properties of Rickettsia mooseri.

The passive permeability properties of Rickettsia mooseri to both inorganic and organic solutes have been examined. Visual observations by phase-contrast microscopy of rickettsiae in macerated yolk sacs taken directly from heavily infected eggs revealed plasmolysis with hypertonic NaCl and KCl as well as with sucrose solutions. In contrast, similar visual studies of rickettsiae which had been subjected to freezing or to a purification process, or both, were plasmolyzed by hypertonic sucrose but not by hypertonic NaCl and KCl. These primary observations were extended to a variety of solutes and were placed on a quantitative basis by use of optical density and radioisotope dilution methods. Intracellular Na(+) and K(+) concentrations in processed rickettsiae, measured by flame photometry, closely paralleled the concentration of these ions in the suspending medium. It was concluded that R. mooseri appears to possess an osmotically active, functional, and structural membrane distinct from the cell wall, located at the surface of a structure analogous to the bacterial protoplast. In the intact organism, this membrane is passively impermeable to sucrose, NaCl, and KCl. However, altered permeability properties, especially to inorganic electrolytes, may be expected in rickettsiae which have been stored in the frozen state and subjected to a lengthy purification process.

Animals↗

[Human ovarian myosarcoma and its cell culture (author's transl)].

One case of a very rare myosarcoma of ovarium origin was observed and establishment of its cell lines from the fluid obtained by paracentitis was accomplished. This report is on the determination of the tumor and the biological characteristics of its cultured cells. (Determination of the tumor) (1) This tumor was diagnosed as a malignant of the right ovary, using bimanual examination, selective angiography of the uterine artery, ultrasonic tomography, and abdominal ascitic cell examination. (2) The morphological type of tumor was based findings of hematoxylin eosin. Silver, Mallory and phosphotungstic acid hematoxylin stainings. The tumor was diagnosed as an ovarian sarcoma and probably myogenic. However, a clear cross strain could not be demonstrated. (Cell biological characteristics) (1) Morphological characteristics of cultured cells: a) Phase-contrast microscopy and Papanicolaou staining revealed round or short and spindle shaped cells, with markedly enlarged nucleoli. These proliferated without exhibiting any tendency of contact inhibition. Also frequently recognized were giant cells, multinuclear cells, an some bizarre such as a starfish-shaped cell. b) Electron microscopy revealed that bundles of fibrils regarded as myofibrils existed in the cytoplasma, with dense patches within them, but a cross strain could not be demonstrated. (2) Morphological characteristics of the tumor cells grown in a nude mouse: a) The tumor cells demonstrated similarities to the original tissues by of H.E., Silver, and Mallary stainings. b) A number of fibrils recognized by the electron microscopic observation were 100 A in width and were arranged in a concentric circles. In addition to the light microscopic findings, the above findings indicated that this cell line originated from myogenic sarcoma. (3) Biological characteristics of the cultured cells: a) The number of chromosomes varied widely and spread aneuploidically, the highest chromosome number was 76. b) Doubling time, Saturation density, and plating efficiency was 31.2 hr, 1.2 x 10(5)/cm2 and 43.9% respectively. c) These cells had a high sensitivity for trypsin and started morphological change rapidly.

Animals↗

In vitro effects of aminoglycosides and fluoroquinolones on keratocytes.

PURPOSE: Commonly used fluoroquinolones are reported to have less of an effect than aminoglycosides on corneal epithelial cells. The purpose of this study was to assess the effects of these antibiotics on stromal keratocytes in vitro. METHODS: Cultured rabbit keratocytes were incubated with various concentrations of gentamicin, tobramycin, ofloxacin, norfloxacin, and ciprofloxacin. Evaluations were performed by means of phase-contrast microscopy and [3H]thymidine uptake assay after 24 hours and 48 hours of incubation with the drug (concentrations from 3 to 0.003 mg/ml). RESULTS: At a concentration of 3 mg/ml, all three fluoroquinolones inhibited keratocyte proliferation significantly more than either aminoglycoside after 24 hours (P<0.001) and after 48 hours (P<0.001). In contrast to the aminoglycosides, all three fluoroquinolones induced a dose- dependent inhibition of proliferation after 24 hours. Even at the lowest concentration (0.003 mg/ml), ofloxacin and norfloxacin inhibited keratocyte proliferation significantly (P=0.001) compared to control after 24 hours. Concentrations of fluoroquinolones ranging from 0.09 to 0.24 mg/ml produced a 50% inhibition of proliferation, a level of inhibition not observed with any tested concentration of aminoglycosides. After 24 hours, all three fluoroquinolones, but neither of the aminoglycosides, showed moderate to severe signs of cytotoxicity at a concentration of 3 mg/ml. CONCLUSIONS: Relative effects of fluoroquinolones and aminoglycosides on epithelial cells and stromal keratocytes appear to be different. This might have an impact on choosing the optimal antibiotic drug to be applied prophylactically in clinical situations in which the epithelium is absent, such as after photorefractive keratectomy or chemical burn.

Aminoglycosides↗

Evaluation of Sysmex UF-100 urine flow cytometer vs chamber counting of supravitally stained specimens and conventional bacterial cultures.

We evaluated the Sysmex UF-100 urine flow cytometer (TOA Medical Electronics, Kobe, Japan) with 269 uncentrifuged urine specimens by comparing it with Sternheimer staining and particle counting in 1-microL disposable chambers with both brightfield and phase-contrast microscopy (the reference method). Results of routine test strip analysis, sediment microscopy (182 specimens), and bacterial culture (204 specimens) were also available. Detection of urinary WBCs and RBCs was highly reliable with the UF-100 compared with manual chamber counting (r = .98 and .88, respectively). Identification of bacteria was equal to that with visual microscopy of uncentrifuged specimens; sensitivity was 55%, and specificity 90%, compared with bacterial cultures at a cutoff of > 10(3) colony-forming units per milliliter. Renal damage was difficult to evaluate even with manual methods because of the low counts of renal tubular cells and casts; with standard manual Sternheimer-stained sediment analysis, sensitivity was 65% to 69% and specificity 66% to 91%, compared with the uncentrifuged chamber method at a cutoff of 3 and 10 particles per microliter, respectively. Renal damage was demonstrated with the UF-100 with a sensitivity of 26% to 69% and specificity 92% to 94%, compared with chamber counts. Automated urinalysis with the UF-100 urine flow cytometer offers considerable savings in time and labor. When high sensitivity is needed, visual microscopic review should be performed to detect renal disease.

Autoanalysis↗

Free radicals are involved in methylmethacrylate-induced neurotoxicity in human primary neocortical cell cultures.

Methylmethacrylate monomer (MMA), a highly volatile material, has been extensively used for the construction of complete or partial dental prostheses. While previous studies have indicated a variety of complications and untoward side-effects associated with its use, the possible neurotoxicity induced by this monomer has not been addressed. In this study, we have investigated the MMA-produced neuronal injury in human neuron-enriched primary culture. Embryonic brain tissue (8-10 weeks postconception) was used for the primary neuron-enriched culture. Phase-contrast microscopy was used to evaluate morphological changes of cultured neurons. Extracellular concentrations of lactate dehydrogenase (LDH) and nitrite was measured from the culture medium to assess the magnitude of neuronal damage and nitric oxide formation, respectively. Neocortical neurons exposed to the monomer (1/200, Vmonomer/Vglycerol) for two days resulted in a significant increase in the LDH level but monomer (1/20000, 1/2000, or 1/200; Vmonomer/Vglycerol) failed to increase the nitrite level. Morphologically, the neurons subjected to monomer treatment exhibited irregular shrunken cell bodies with dystrophic and/or fragmented neurities, or even cell lysis. Moreover, superoxide dismutase plus catalase or vitamin C pretreatment protected against monomer-induced neurotoxicity. Our results suggest that this neurotoxicity can not likely be attributed to the cytotoxic effects of nitric oxide but may be mediated through the toxicity of superoxide and other free radicals. This is the first time, to our knowledge, that neurotoxicity induced by MMA has been demonstrated in human cortical neurons.

Ascorbic Acid↗

Microscopic hematuria: advances in identification of glomerular dysmorphic erythrocytes.

The high diagnostic sensitivity and specificity of microscopically visible, typically glomerular dysmorphic erythrocytes for identification of the cause of glomerular bleeding have been recognized worldwide. Although glomerular dysmorphic erythrocytes are simple to detect on phase contrast microscopy, immediate microscopic diagnosis still is indispensable, since a change in the morphology of the erythrocytes with restriction of the diagnostic relevance is anticipated because of the high autolytic potency of the urine. It may be postulated that this need for immediate diagnosis has led to the method being neglected owing to the high work load at hospitals and physician offices. Moreover, a physician who does not perform microscopic investigations or who lacks experience with the method will not be able to use this diagnostic technique, since it appeared to be impossible to transport urine samples by mail. In the context of a study comprising 30 patients, of whom 10 had histologically confirmed glomerulonephritis, we have shown that glomerular dysmorphic erythrocytes have a manifest form stability for at least 3 days. The preservative used was thimerosal. Also, the urine can be investigated independent of time even after alcoholic Papanicolaou staining without an alteration of erythrocyte morphology. The practicality of the form stability of glomerular erythrocytes can be exploited in everyday medical routine. There are well founded prospects that the rate of early diagnosis of glomerulonephritis will increase.

Erythrocytes, Abnormal↗

Water-mediated lysis of lens epithelial cells attached to lens capsule.

PURPOSE: To investigate the effect of distilled deionized water (DDW) on lens epithelial cells (LECs) attached to the lens capsule. SETTING: Wound Healing Research Laboratory, Center for Vision Research, Westmead Hospital, Sydney, NSW, Australia. METHODS: Anterior capsulotomy specimens taken during routine cataract surgery were divided in half. One half was immersed in DDW and the other half in culture medium (control) for 1 to 5 minutes and photographed at intervals by phase-contrast microscopy. In further experiments, the capsules were exposed to DDW for 1 or 2 minutes and placed in culture for 1 week to determine whether LECs survive treatment and are capable of repopulating the lens capsule. RESULTS: Distilled-deionized water induced marked swelling of the cytoplasm within 60 seconds of treatment. At 120 seconds, there was disruption of the plasma membranes, with few intact cells remaining. In the control capsules, confluent monolayers of LECs covered the entire capsule surface with a halo of LECs growing on the surrounding plastic well. Viable LECs were observed in 1 of 3 capsules treated for 1 minute with DDW. These did not reach confluence or grow off the capsule onto the surrounding well. No viable LECs were seen on capsules exposed to DDW for 2 minutes. CONCLUSIONS: Short exposure of LECs to DDW induced extensive and rapid cell lysis. Distilled-deonized water may be a useful agent for instillation in the capsular bag during sealed-capsule irrigation to prevent posterior capsule opacification.

Cataract Extraction↗

Growth factors protect in vitro cultured embryos from the consequences of oxidative stress.

The aim of the study was to evaluate the effect of insulin-like growth factors (IGF1 and IGF2), stem cell factor (SCF) and epidermal growth factor (EGF) on the development of embryos exposed to oxidative stress. C3B6F1 female mice were stimulated with 5 IU of pregnant mare serum gonadotropin and 5 IU of equine chorionic gonadotropin (eCG). Two-cell embryos were flushed out from the fallopian tubes 40 h after eCG administration and mating with DBA males. In each experiment embryos were divided into three groups and cultured in (1) control medium, (2) control medium with 0.1 mM hydrogen peroxide and (3) control medium with hydrogen peroxide and separately with IGF1, IGF2, SCF or EGF in concentrations of 1 ng/ml, 10 ng/ml and 100 ng/ml. Under phase-contrast microscopy, 8-cell and compacted embryos, and early, expanded, hatched and outgrown blastocysts were counted at 24 h. The total blastocyst (TB) and inner cell mass (ICM) cell numbers were established by differential staining. Blastocyst cell viability was examined under fluorescence microscopy. To detect apoptosis, TUNEL was performed and visualized under a laser scanning confocal microscope. Hydrogen peroxide decreased embryo growth, blastocyst rates, blastocyst cell viability as well as TB and ICM counts. The TUNEL reaction revealed significantly more apoptotic cells in oxidative stress conditions. Tested factors revealed a varying extent of protective activity against oxidative stress caused by hydrogen peroxide. In media containing hydrogen peroxide and one of the four tested factors (IGF1, IGF2, SCF or EGF) the embryos developed faster than in media with hydrogen peroxide alone. IGF1, IGF2 and EGF increased both TB and (or) ICM counts in embryos exposed to hydrogen peroxide. All tested factors reduced the number of apoptotic cells (TUNEL) in embryos exposed to hydrogen peroxide.

Animals↗

Biochemical and microscopic urinalysis: time and cost in a nephrology laboratory.

BACKGROUND: Urinalysis is a fundamental test in internal medicine and nephrology. Figures for costs are available in the general laboratory, where biochemical and microscopic urinalysis are commonly performed as semiautomated screening tests. Information on costs is lacking in the nephrology laboratory, where a time-consuming morphological analysis is usually preferred. This study analyses the costs of urinalysis in a nephrology laboratory. METHODS: In the nephrology laboratory at the University of Turin - Italy, biochemical urinalysis consists of multi-property strip and proteinuria/creatininuria, done by laboratory technicians. Phase-contrast microscopy is done by a nephrologist or biologist. Time dedicated to the tests was recorded by the same operator over 20 working days, during which 350 urine samples were processed (median 19/day, range 842). The production costs were calculated with the logic bottom-up technique. RESULTS: Overall time needed was 11.9 minutes/sample. Biochemical urinalysis required 6.6 minutes/sample; time required and samples processed were inversely related (< or =19 samples: 7.95 minutes/sample; >19 samples: 5.6 minutes/sample, p=0.01). Microscopic urinalysis took 5.3 minutes/slide; the best time-to-samples ratio was at 18-22 samples per day (with peak efficiency at 21 samples: 4.6 minutes). Cost of reagents and disposables was Euro1.06/sample. Time accounted for euro 5.32/sample (technicians, nephrologist-biologist), with total direct cost of euro 6.38/sample. CONCLUSION: In a nephrology laboratory, microscopic urinalysis is a time-consuming, expensive test. Analysis of cost and modalities may be useful, in a time of budget constrains, to maintain a role for this precious semeiotic art.

Chemistry, Clinical↗