Showing papers by "University of Milan published in 1993"

Synaptic Vesicle Phosphoproteins and Regulation of Synaptic Function

Abstract: Complex brain functions, such as learning and memory, are believed to involve changes in the efficiency of communication between nerve cells. Therefore, the elucidation of the molecular mechanisms that regulate synaptic transmission, the process of intercellular communication, is an essential step toward understanding nervous system function. Several proteins associated with synaptic vesicles, the organelles that store neurotransmitters, are targets for protein phosphorylation and dephosphorylation. One of these phosphoproteins, synapsin I, by means of changes in its state of phosphorylation, appears to control the fraction of synaptic vesicles available for release and thereby to regulate the efficiency of neurotransmitter release. This article describes current understanding of the mechanism by which synapsin I modulates communication between nerve cells and reviews the properties and putative functions of other phosphoproteins associated with synaptic vesicles.

Diagnostic criteria for the long QT syndrome. An update.

Abstract: T he idiopathic long QT syndrome (LQTS) is a congenital disease with frequent familial transmission, characterized primarily by prolongation of the QT interval and by the occurrence of life-threatening tachyarrhythmias, particularly in association with emotional or physical stress.1-5 Among untreated symptomatic patients, lethality is high, with 20% mortality in the first year after the initial syncope and approximately 50% within 10 years3; however, the risk of death varies among different families. This poor prognosis has been significantly improved by the use of pharmacological or surgical antiadrenergic therapy or both, which has reduced long-term mortality to <5%.3,4,6 The availability of effective therapy for this often lethal disease emphasizes the importance of early and accurate diagnosis. Unfortunately, there is frequently a delay in the diagnosis of LQTS, and patients with syncope are often misdiagnosed, most commonly as affected by a seizure disorder. In its most characteristic presentation, with obvious QT prolongation and stress-induced syncope, the diagnosis of LQTS is quite straightforward for physicians aware of the disease. In cases of borderline QT prolongation and/or absence of symptoms, however, a correct diagnosis may be more difficult. It was for this reason that a first set of diagnostic criteria (Table 1) was proposed in 1985.3 The major merit of that proposal was that it provided a logical and quantitative approach to the clinical diagnosis of LQTS by giving a different weight to major and minor criteria. Its major limitation was that it used the traditional, but untested for diagnostic purposes, cutoff value of QT, >440 msec '2. This also resulted in a rather black-and-white situation in which patients were judged to have an entirely normal or abnormal duration of ventricular repolarization on the basis of a difference of a few milliseconds in a measurement fraught with difficulties, such as interobserver variability.7

Pacemaker Mechanisms in Cardiac Tissue

Abstract: The heartbeat is a sign of life, and not surprisingly it has attracted much interest and curiosity since the early stages of scientific investigation. Even Leonardo da Vinci, in his anatomical studies, realized that rhythmic, restless activity was an intrinsic property of cardiac muscle (92), "As to the heart: it moves itself, and doth never stop, except it be for eternity." In fact, a search for the basis of spontaneous cardiac activity could only be undertaken several centuries after these primitive observations with the development of techniques that allowed the study of the electrical properties of excitable tissues and particularly of cardiac muscle (18, 71,77,23). Cardiac pacemaker activity originates in specialized myocytes located in restricted areas of the heart that are characterized by the ability to beat spontaneously even when separated from the rest of the cardiac muscle (24, 106, 103, 11, 81). Voltage-clamp investigation of pacemaker tissue opened the way to a better understanding of the ionic mechanisms promoting rhythmicity in pacemaker tissue (64, 6). In pacemaker cells of the mammalian sino-atrial (SA) node, spontaneous activity results from a typical phase of their action potential, the slow diastolic depolarization. The concept that a slow depolarization is an inherent property of spontaneously active myocar­ dium is an old one that has been actively investigated since the first recordings of cardiac electrical activity revealed the existence of a slow depolarizing phase preceding the action potential onset in beating tissue (for a review, see 105). During this phase, corresponding to diastole of the cardiac contraction cycle, the membrane slowly depolarizes following termination of an action potential, until threshold for a new action potential is reached. Thus, the

Antigen unmasking on formalin-fixed, paraffin-embedded tissue sections

Abstract: Enzymatic and non-enzymatic treatments for antigen unmasking on formalin-fixed, paraffin-embedded, dewaxed sections were optimized and compared by the use of a panel of antibodies of diagnostic relevance (anti-cytokeratins, vimentin, S-100, T- and B-cell receptors, Ki-67/MIB 1, muscle actin). Non-enzymatic unmasking was obtained by boiling the slides in a microwave oven in 0.01 M salt solution (pH 6) or in 6 M urea. Trypsin or pronase digestion was used for comparison and found to be necessary for some of the reagents. The investigation was then extended to 256 antibodies; the epitopic amino acid sequence was known for 48 of them. We found that enzymatic and non-enzymatic antigen unmasking are not dependent on the epitope sequence, but some antigens benefit selectively from one treatment but not from the other. Denaturation of proteins is the likely mechanism which leads to immunodetection on microwave oven-boiled slides; this suggestion is supported by the use of denaturating solutions and by the observation that endogenous enzymes were inactivated and a few antigens were no longer immunodetectable after boiling. Non-enzymatic methods for antigen unmasking are a powerful new tool for broadening the use of antibodies for immunostaining formalin-fixed, paraffin-embedded sections and should be used in parallel with the traditional enzymatic methods.

Prognostic value of 24-hour blood pressure variability.

Abstract: Objectives: Evaluation of the prognostic value of 24-h blood pressure averages and 24-h blood pressure variability. Design: After an initial thorough clinical and laboratory evaluation which included 24-h continuous ambulatory blood pressure monitoring, a group of hypertensive patients were re-examined after an average of 7.4 years. End-organ damage at the follow-up visit was related to different measures of blood pressure levels and variability obtained at the initial or the follow-up visit or both

How to use expert advice

Abstract: We analyze algorithms that predict a binary value by combining the predictions of several prediction strategies, called `experts''. Our analysis is for worst-case situations, i.e., we make no assumptions about the way the sequence of bits to be predicted is generated. We measure the performance of the algorithm by the difference between the expected number of mistakes it makes on the bit sequence and the expected number of mistakes made by the best expert on this sequence, where the expectation is taken with respect to the randomization in the predictions. We show that the minimum achievable difference is on the order of the square root of the number of mistakes of the best expert, and we give efficient algorithms that achieve this. Our upper and lower bounds have matching leading constants in most cases. We then show how this leads to certain kinds of pattern recognition/learning algorithms with performance bounds that improve on the best results currently known in this context. We also extend our analysis to the case in which log loss is used instead of the expected number of mistakes.

Sensory Impairment and Quality of Life in a Community Elderly Population

Abstract: Objective: To determine the association between quality of life measures and sensory impairment in aged individuals living at home. Design: Survey Setting: A community survey, carried out in the historical center of a town in Northern Italy. Patients: 1191 non-institutionalized elders (age 70–75 years). Measurements: Comprehensive QOL questionnaire, free-field voice testing, and Snellen eye chart. Results: Single sensory impairments (either visual or auditory) were significantly and independently associated with increased risk for depression (odds ratio: 2.3, 95% confidence interval: 1.5–3.4; OR:1.8, CI:1.1–2.7, respectively) and decreased self-sufficiency in daily living activities (OR: 1.7, CI:1.1–2.6; OR:2.1, CI:1.4–3.2, respectively). Visual dysfunction, but not hearing dysfunction, was independently associated with lower social relationships (OR:2.0, CI:1.3–3.1). Conclusion: The quality of life of community-dwelling elderly people is significantly linked to sensory impairment, which can be detected through simple physical examination. Mood level and social relationships are particularly affected by visual impairment, whereas self-sufficiency in daily living is more strongly related to hearing impairment.

Regional effects and mechanism of positive end-expiratory pressure in early adult respiratory distress syndrome.

Abstract: Objective. —To test the hypothesis that positive end-expiratory pressure (PEEP) prevents the collapse of a given lung region when it is equal to or greater than the hydrostatic pressure superimposed (SPL) to that region. Design. —Intervention study with sequential levels of PEEP applied in random order to a cohort of patients with adult respiratory distress syndrome (ARDS). Setting. —Referral center for ARDS in a university hospital. Patients. —Ten ARDS patients (with Murray scores >2.5). Intervention. —Basal computed tomographic (CT) section taken at o, 2, 4, 5, 6, 8, 10, 12, 14, 15, and 20 cm H 2 O PEEP. Main Outcome Measures. —Basal lung CT sections were divided into 10 equal levels from the ventral to dorsal surfaces. In each level SPL was measured from density and height. The inflation of the level was measured as the gas/tissue ratio (g/t); g/t changes with PEEP were defined as the g/t—P curve. The slope of the g/t—P curve was defined as level compliance (ie, the ratio of change in the g/t of the level to the change in pressure). A linear g/t—P curve was the criterion to detect inflation without recruitment (ie, new pulmonary units opening at a given pressure). A biphasic g/t—P curve (change of compliance after an inflection point) was the criterion to detect recruitment. Pflex was defined as the pressure at which the inflection point occurred. Results. —The SPL increased from level 1 (ventral) to level 10 (dorsal) ( r =.91; P r =.98; P r =.95; P r =.97; P r =.75; P Conclusions. —The increased SPL causes compression atelectasis; this is prevented when PEEP to a given lung region is equal to or greater than the SPL. ( JAMA . 1993;269:2122-2127)

Urokinase and urokinase receptor: a paracrine/autocrine system regulating cell migration and invasiveness.

Abstract: Urokinase and its receptor are essential components of the cell migration machinery, providing an inducible, transient and localized cell surface proteolytic activity. This activity has been shown to be required in normal and pathological forms of cellular invasiveness (i.e. in several embryonic developmental processes, during inflammatory responses and cancer metastasis and spreading). It represents one of the best known of the proteolytic systems which are currently under investigation in this field. The urokinase receptor allows a continuous regulation of the proteolytic activity at cell contacts, utilizing the different localization of urokinase and its inhibitors. The receptor, in fact, in addition to focusing the enzymatic activity at focal and cell-cell contacts, also regulates it by internalizing and degrading only the inhibited form of urokinase. Internalized receptor releases the ligands to the lysosomes and recycles back to surface. In this way, the proteolytically active areas of the cell surface can be continuously monitored for their activity and their location modified. The cell can thus coordinate its migration efforts with a step-wise modification of the proteolytic activity-map of the cell surface. The urokinase cycle can be supported by one individual cell (autocrine) or by two or more cells. In the latter case, complementation and synergism of urokinase and its receptor are found.

Primary amenorrhoea and infertility due to a mutation in the beta-subunit of follicle-stimulating hormone

Abstract: We report a woman with primary amenorrhoea and infertility associated with an isolated deficiency of pituitary follicle–stimulating hormone (FSH), but normal luteinizing hormone (LH) secretion. Ovulation was induced by administration of exogenous FSH and resulted in a successful pregnancy. Sequence analysis of the FSHβ–subunit gene indicated that she is homozygous for a two nucleotide frameshift deletion in the coding sequence. Her mother and son are heterozygous for this mutation. This deletion results in an alteration of amino acid codons 61–86 followed by a premature termination codon. The predicted truncated β–subunit peptide lacks regions which are important for association with the α subunit and for binding to and activation of the FSH receptor. Abnormalities of FSH structure or function might be an under recognised but treatable cause of infertility.

Intratumoral microvessel density and p53 protein: correlation with metastasis in head-and-neck squamous-cell carcinoma.

Abstract: Squamous-cell carcinoma of the head and neck includes a heterogeneous group of tumours of the upper air and food passages for which prognosis is difficult to assess. In fact, patients in comparable stages may have diverse clinical courses and responses to similar treatments. In order to better define the prognosis of each patient there is therefore a need to identify novel biological markers which reflect more accurately growth rate, progression and metastatic potential of each tumour. We assessed whether metastases correlate with micro-vessel counts (i.e. intratumoral vascularity) using the CD-31 monoclonal antibody (MAb) and p53 mutant protein expression, determined in the primary by immunocytochemical methods in 70 patients with locally advanced head and neck cancer. Patients were treated with concurrent chemo-radiotherapy; 50 of these presented loco-regional node metastasis at diagnosis whereas 3 cases, initially node-negative, developed distant metastasis during the period of observation. No feature was predictive for objective response to treatment. The overall mean and median blood vessel density at “hot spots” was 37.42 and 36, respectively, and 57% of the tumours expressed p53 mutant proteins. These 2 biological markers were significantly associated. Patients with metastases (loco-regional and distant) had a significantly higher mean blood-vessel density than those without tumour spread. Also, patients with p53-positive (+/ + +) tumours had a significantly higher incidence of metastasis than those with negative ones. Multivariate analysis showed that both vascularity and stage, but not p53 expression, are significant and independent predictors of metastasis in this series.

Decreased expression of myotonin-protein kinase messenger RNA and protein in adult form of myotonic dystrophy.

Abstract: The myotonic dystrophy mutation has recently been identified; however, the molecular mechanism of the disease is still unknown. The sequence of the myotonin-protein kinase gene was determined, and messenger RNA spliced forms were identified in various tissues. Antisera were developed for analytical studies. Quantitative reverse transcription-polymerase chain reaction and radioimmunoassay were used to demonstrate that decreased levels of the messenger RNA and protein expression are associated with the adult form of myotonic dystrophy.

Diagnostic value of blood sampling in fetuses with growth retardation.

Abstract: Background Fetuses with intrauterine growth retardation are delivered if they have evidence of distress, as manifested by abnormalities in the fetal heart rate and umbilical-artery blood flow. We studied whether umbilical-blood sampling might provide further information useful for management. Methods We measured hemoglobin and lactate concentrations, oxygen content, pH, blood gas levels, and base deficit in umbilical-vein blood and correlated these measurements with the heart rate and umbilical-artery wave forms recorded by Doppler velocimetry in 56 fetuses with growth retardation. Twenty-one fetuses had normal heart rates and normal results of velocimetry, 24 had normal heart rates and abnormal results of velocimetry (indicative of decreased diastolic flow), and 11 had abnormal heart rates and abnormal results of velocimetry. Results None of the 21 fetuses with normal heart rates and velocimetry had hypoxia or acidemia. Of the 24 fetuses with normal heart rates and abnormal velocimetry, 4 (17 percent) ha...

Codistribution of GABA- with acetylcholine-synthesizing neurons in the basal forebrain of the rat.

Abstract: In recent years, GABAergic neurons have been identified in the basal forebrain where cholinergic cortically projecting neurons are located and known to be important in mechanisms of cortical activation In the present study in the rat, the relationship of the GABA-synthesizing neurons to the acetylcholine-synthesizing neurons was examined by application of a sequential double staining immunohistochemical procedure involving the peroxidase-antiperoxidase technique for glutamic acid decarboxylase (GAD) and choline acetyltransferase (ChAT) In these double and adjacent single immunostained series of sections, the GAD+ and ChAT+ cells were mapped, counted and measured with the aid of a computerized image analysis system Through the entire basal forebrain, there was no evidence for colocalization of GAD and ChAT in the same neurons Instead, a large population of GAD-immunoreactive neurons is codistributed with ChAT-immunoreactive neurons and outnumbers them by a factor of two: approximately 39,000 GAD+ cells to 18,000 ChAT+ cells Although the GAD+ and ChAT+ neurons lie intermingled within fascicles of the major longitudinal and transverse forebrain fiber systems in subregions of the basal forebrain, the GAD+ cells are more highly concentrated within different sectors of the pathways and regions than the ChAT+ cells Although GAD+ neurons resemble ChAT+ neurons in certain regions, both being bi- or multipolar and, on average, medium-sized cells, the GAD+ neurons are, in the majority (51%), small-sized cells (< 15 microns in length) and as a population significantly smaller than the ChAT+ neurons These results suggest that many GABAergic neurons may represent interneurons in the basal forebrain and potentially exert an inhibitory influence on adjacent cortically projecting cholinergic neurons Medium- to large GAD+ cells, which resemble similar ChAT+ cells, are also present and represent the majority of the GAD+ cells in the nucleus of the diagonal band of Broca, magnocellular preoptic nucleus, and olfactory tubercle, but represent the minority in the anterior and posterior substantia innominata and globus pallidus Given their prominent size, such GABAergic cells may also exert an inhibitory influence outside the basal forebrain as projection neurons and potentially in parallel with cholinergic neurons, to certain regions of the cerebral cortex Accordingly, GABAergic cells may be considered as constituents of the magnocellular basal nucleus and potentially important elements within the ventral extrathalamic relay from the brainstem reticular formation to the cerebral cortex

Primary cutaneous CD30-positive large cell lymphoma: Definition of a new type of cutaneous lymphoma with a favorable prognosis. A European multicenter study of 47 patients

Abstract: Background. CD30 (Ki-1)-positive anaplastic large cell lymphoma (LCL) has been described as a morphologically distinct group of LCL that generally are associated with a poor prognosis. Recent studies indicate that these lymphomas, when confined to the skin, have a favorable prognosis. However, there is no consensus regarding the definition of these primary cutaneous CD30-positive LCL. Reported patients have been selected variously on the basis of morphologic (anaplastic cytology) or immunophenotypical (expression of CD30 antigen) criteria. Methods. At two recent workshops aimed to achieve consensus on the definition and terminology of these lymphomas, the clinical, histologic, and immunophenotypical data of 47 patients with primary cutaneous CD30-positive LCL from five collaborating European centers were analyzed. Results. Characteristic clinical features were presentation with solitary or localized skin lesions (42 of 47 patients), frequent cutaneous relapses (15 patients), and partial or complete spontaneous remission of skin lesions (11 patients). Twelve of 47 (25%) patients developed extracutaneous disease. The favorable prognosis of these lymphomas is indicated by the follow-up data that show that 36 of 47 patients are alive and in complete remission, only four disease-related deaths have occurred, and the overall median survival is 42 months (range, 2–130 months). There were no differences in clinical presentation, course, or prognosis between anaplastic and nonanaplastic CD30-positive LCL. Conclusion. The results of this study indicate that primary cutaneous CD30-positive LCL, regardless of their morphologic classification (anaplastic or nonanaplastic) can be considered as a distinct type of cutaneous T-cell lymphoma. Recognition of this type of cutaneous lymphoma is important because it may prevent patients from unnecessary aggressive treatment.

Cancer Incidence in a Population Accidentally Exposed to 2,3,7,8-Tetrachlorodibenzo-para-dioxin

Abstract: In 1976, an accident in a plant near Seveso, Italy, exposed the local population to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Persons residing in three zones of decreasing TCDD contamination (A, B, and R) and a reference population were followed up for cancer occurrence in 1977–1986. The most expo

Properties of the hyperpolarization-activated current in rat hippocampal CA1 pyramidal cells

Abstract: 1. Voltage and current clamp recordings were performed on CA1 rat hippocampal pyramidal cells using the patch clamp technique on "in vitro" slice preparations. 2. Hyperpolarizations from a holding potential of -35 mV elicited activation of the hyperpolarization-activated current (Ih) starting at voltages near -50 mV. 3. Ih recorded in voltage clamp conditions was blocked by external caesium (5 mM). 4. Raising the external K concentration from 4.35 to 24.35 mM sensibly increased the slope of the current-voltage (I/V) curve. Decreasing the external Na concentration from 133.5 to 33.5 mM depressed Ih without grossly altering the I/V slope. 5. The Ih fully activated I/V relation measured in the range -140 to -45 mV was linear with an extrapolated reversal at -17.0 +/- -1.6 (SE) mV. The current activation curve comprised the range between about -50 and -140 mV with a half-maximal activation at about -98 mV. 6. Perfusion of unclamped neurons with Cs (2 mM) hyperpolarized their resting potential by 3.8 +/- 0.2 mV and decreased the membrane conductance, as expected if Ih were activated at rest. Firing caused by depolarizing current steps was prevented by Cs-induced hyperpolarization, and could be restored by returning the membrane voltage to resting level by constant current injection. 7. The Cd-insensitive (medium-duration) afterhyperpolarization (AHP) elicited by a train of action potentials at -60 mV had an amplitude of 3.9 +/- 0.3 mV and was nearly fully abolished by 2 mM Cs (82.7 +/- 7.4%). Cs removed the depolarizing part of the afterhyperpolarization as expected if Ih activation was responsible for this phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma and platelet excitatory amino acids in psychiatric disorders

Abstract: Plasma and platelet levels of excitatory amino acids were measured in 38 psychiatric outpatients and in 1 9 comparison subjects; the patients had DSM-III-R diagnoses of organic mental disorders (N=3), mood disorders (N=1 5), schizophrenia (N=13), and anxiety disorders (N=7). The glutamate plasma levels were significantly higher in the patients with mood disorders than in the comparison group. (Am J Psychiatry 1993; 150:1731-1733)

HMG CoA reductase inhibitors. In vivo effects on carotid intimal thickening in normocholesterolemic rabbits.

Abstract: The in vivo activity of different 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (vastatins) on neointimal formation induced by insertion of a flexible collar around one carotid artery of normocholesterolemic rabbits was investigated. The contralateral carotid artery served as a sham control. Pravastatin, lovastatin, simvastatin, and fluvastatin were given mixed with food at daily doses of 20 mg/kg body wt for 2 weeks starting on the day of collar placement. The treatment with vastatins did not modify rabbit plasma cholesterol concentrations. The neointimal formation was assessed by measuring the cross-sectional thickness of intimal and medial tissues of fixed arteries with light microscopy. Fourteen days after collar placement, intimal hyperplasia (mostly cellular) was pronounced in treated carotid arteries. The intimal/medial (I/M) tissue ratio was 12-fold higher in treated arteries than in arteries without the collar (0.36 +/- 0.04 versus 0.03 +/- 0.02). Animals treated with lovastatin (n = 12), simvastatin (n = 12), and fluvastatin (n = 12) showed significantly less neointimal formation; I/M tissue ratios were 0.24 +/- 0.03, 0.20 +/- 0.03, and 0.17 +/- 0.03, respectively. The inhibition elicited by pravastatin (n = 12, 0.32 +/- 0.03) did not reach statistical significance. alpha-Actin antibody immunofluorescence analysis of serial sections revealed that cells present in the hyperplastic intima were mostly myocytes. Rates of intimal myocyte proliferation were also measured by incorporation of 5-bromo-2'-deoxyuridine, a thymidine analogue, into replicating DNA. Immunofluorescence analysis showed that 5-bromo-2'-deoxyuridine was actively incorporated into intimal myocytes after ++reinsertion of the collar, with a labeling index (percent of labeled myocytes) of 2.15 after 14 days.(ABSTRACT TRUNCATED AT 250 WORDS)

α-Melanocyte Stimulating Hormone in the Modulation of Host Reactions

Abstract: I. Introduction α-MELANOCYTE-stimulating hormone (αMSH), a basic tridecapeptide, is derived from the precursor molecule POMC(l). The amino acid sequence of αMSH is identical to the 1–13 (N-terminal) amino acid sequence of ACTH although αMSH has little direct influence on glucocorticoid release from the adrenal gland. αMSH is found mainly in the pituitary, but it also occurs in lower concentrations in the central nervous system (CNS), the skin, and other sites (1). This peptide was named for its effect on pigmentation in amphibian skin, although its distribution in tissues of higher organisms suggests that it is important to other functions. Phylogenetically, αMSH is an “ancient” molecule, little changed over the last few hundred million years, and there is remarkable conservation of its amino acid sequence across species. Evidence that this endogenous neuropeptide is important to limitation of fever and inflammation in mammals, including man, suggests that αMSH has retained a role as a modulator of host r...

Ambulatory blood pressure monitoring use in hypertension research and clinical practice

Abstract: In his article on blood pressure measurement by sphygmomanometry published in 1897 in the Gazzetta Medica di Torino,' Riva Rocci wrote the following: \"Blood pressure is acted upon, in a temporary but pronounced fashion, by the state of 'psychic' excitation of the patient. It is enough that the patient is spoken to, that he is invited to read, that he is even looked at suddenly, or that a sudden and even far noise strikes him (e.g., a carriage passing by in the outside street) that his blood pressure raises, and not at all to the same extent in all patients. This emotional reaction may be useful in psychiatry, but in other disciplines these blood pressure rises represent an inconvenience, and it is therefore necessary for the patient to be put in an environment as quiet as possible. . . . Furthermore, because even the application of the instrument causes a temporary blood pressure rise, it is necessary to take not only one but several consecutive blood pressures spaced by 3or 5-minute intervals until a constant value is measured. This value, however, is not always the minimal value.. . . It should not be necessary to add that it will not be proper to compare data unless obtained in identical conditions or environment, position, time of day, distance from meals, wakefulness, etc. This remark is certainly superfluous for the investigators, but it may be useful to practitioners whose hurry may in this case result in a waste rather than a gain of time.\