[Proposing a teaching program for the first of the 3 "I's" (english, informatics, internet) in medicine and surgery in Italy]. / Una proposta di programmazione didattica della prima delle tre "i" (inglese, informatica, internet) in Medicina e Chirurgia.

BACKGROUND: Since the beginning of the 90s, medical students in Italian Faculties have been required to pass a compulsory English exam. In the light of the growing importance of reasonably fluent spoken and written English at the start of the new millennium, the authors present an English teaching program spanning the 6 years of medical studies leading to a degree in Medicine and Surgery. THE PROGRAM: Features an initial test of basic English proficiency; the specific terminology: macroscopic anatomy, physiology, etc., to be learnt in the 3rd year; the true course in the 4th year, focusing on fluent spoken English, tips for formal correspondence and a knowledge of the typical format and language used in scientific papers; update courses in the form of medical seminars in the 5th and 6th years. CONCLUSION: No graduate in any field can be considered equipped for his/her chosen career unless he/she possesses an adequate knowledge of spoken and written English. The course presented aims to provide Italian medical students with the necessary skills.

[Type of surgical articles. Comparative study of 3 Italian and 3 foreign periodicals]. / Tipi di articoli chirurgici. Analisi comparativa di tre periodici italiani e tre periodici stranieri.

BACKGROUND: Medical progress in the world is divulged to peers and colleagues through books and scientific journals. It is thus linked not only to the quality of articles, but also to their type. MATERIAL AND METHODS: The type of articles published in three Italian periodicals (Annali Italiani di Chirurgia; Chirurgia; Minerva chirurgica) and three foreign periodicals published in English (Annals of Surgery; British Journal of Surgery; Surgery, Gynecology & Obstetrics) was compared. The articles were classified according to their potential contribution to medical progress, being divided into two main groups: research papers and simple case series or case reports. Other types of articles (reviews, description of surgical techniques, editorials etc.) were excluded from the study. RESULTS: Both the total number and the percentage of research papers were markedly superior in the three foreign journals with respect to the three Italian periodicals. All the differences were highly significant. CONCLUSIONS: The number of research papers published in Italian periodicals should be increased. Greater attention should be paid to quality, at the expense of quantity, since serious research inevitably takes longer to perform.

English teaching in the Italian medical faculties: results of a survey.

BACKGROUND: Although a compulsory examination in medical English has been present in the medical degree curriculum in Italy since 1990, guidelines indicating what should be learnt and suggesting some means of overcoming the various problems this entails are still lacking. OBJECTIVE: To investigate the main features of teaching English in the Medical Faculties and enquire into how the various problems are solved in the individual English teaching units. METHOD: A questionnaire addressing the above issues was sent out to all the Italian Universities with a Medical Faculty. RESULTS: The first finding of our survey was that response was very poor: less than 30% of the survey volunteered any reply. Within the very reduced sample which responded, there was a high degree of variation among the solutions adopted, although the underlying problems were perceived to be much the same throughout Italy. CONCLUSIONS: The general objective of the English course for medicine should be more precisely defined, together with a series of specific minimum skills the student should possess to pass the final examination. A closer collaboration among the English teaching units might help to standardize these requirements, improve the quality of the teaching and hence the level of proficiency in English for the specific purpose of medical practice.

Identification of critical amino acids involved in alpha1-beta interaction in voltage-dependent Ca2+ channels.

In voltage-dependent Ca2+ channels, alpha1 and beta subunits interact via two cytoplasmic regions defined as Alpha Interaction Domain (AID) and Beta Interaction Domain (BID). Several novel amino acids for that interaction have now been mapped in both domains by point mutations. It was found that three of the nine amino acids in AID and four of the eight BID amino acids tested were essential for the interaction. Whereas the important AID amino acids were clustered around five residues, the important BID residues were more widely distributed within a larger 16 amino acid sequence. The affinity of the AIDA GST fusion protein for the four interacting beta 1b BID mutants was not significantly altered compared with the wild-type beta 1b despite the close localization of mutated residues to disruptive BID amino acids. Expression of these interactive beta mutants with the full-length alpha 1A subunit only slightly modified the stimulation efficiency when compared with the wild-type beta 1b subunit. Our data suggest that non-disruptive BID sequence alterations do not dramatically affect the beta subunit-induced current stimulation.

A study of some international medical journals aiming to elicit stylistic guidelines for writing publishable papers.

OBJECTIVE: To provide some indications and guidelines on style and presentation for those aiming to publish in selected international journals. SETTING: University library in the Istituto di Clinica Chirurgica, Bari University Hospital. METHODS: A single topic, portal hypertension, was chosen to ensure a certain homogenity for the purposes of comparison, and the three most recent articles on this topic were identified in six international journals (three published in England and three in the USA; three in the medical and three in the surgical field) and studied from the points of view of style and presentation. RESULTS: Strong similarities were found among the 18 selected articles. In the interests of brevity, all were characterized by compact statements, qualified by lists of examples, and strings of adjectival nouns. In all, the Introduction and Conclusions sections were relatively short, the main body of the article being reserved to the Patients and Methods, Results and Discussion/Comments sections. Apart from very slight spelling or grammar differences characterizing English or American usage, all the articles could, with slight alterations in format in some cases, equally well have been published in any other of the journals studied. CONCLUSIONS: Brevity, even at the expense of elegance, and a straightforward, unambiguous, to some extent standardized, approach to the presentation of a scientific study, are essentials for the acceptance of an article for publication in the selected temational journals.

Association of native Ca2+ channel beta subunits with the alpha 1 subunit interaction domain.

beta Subunits of voltage-dependent Ca2+ channels play an important role in regulating Ca2+ channel function. The sites of alpha 1-beta subunit interaction have been localized recently to cytoplasmic domains of both subunits. The alpha 1 subunit interaction domain (AID) is an 18-amino-acid conserved motif located between repeats I and II on all alpha 1 subunits which is essential for the binding of beta subunits. In order to further study the interaction of beta subunits with AID, we have expressed a 50-amino-acid glutathione S-transferase (GST) fusion protein from the alpha 1A subunit that contains the AID. Mutant GST fusion proteins that contain a single amino acid change (Y392S, Y392F, and Y392W) in the AIDA along with control GST were coupled to glutathione-Sepharose beads to form affinity beads. Binding assays using these affinity beads with in vitro synthesized 35S-labeled beta 2 and beta 3 subunits demonstrate that the hydroxyl group on tyrosine 392 of AIDA is critical for binding to beta subunits. The affinity bead assay was also used to identify and characterize native beta subunits from detergent extracts of different tissues. The AIDA affinity beads, but not the control or Y392S beads, specifically bind beta subunits from detergent extracts of skeletal muscle, cardiac muscle, and brain. Immunoblot analyses demonstrate the presence of beta 1a in skeletal muscle, beta 2 and beta 3 in cardiac muscle, and beta 1b, beta 3, and beta 4 in brain. The assays also demonstrate the AIDA beads bind to beta subunits from tissue homogenates extracted with low salt and no detergent suggesting the existence of a pool of beta subunits which is not always associated with alpha 1 subunits. Also, beta subunits from solubilized skeletal muscle triads can be affinity-purified using AIDA CNBr-Sepharose. Our data demonstrate that the AID binds to native beta subunits from detergent and non-detergent tissue extracts illustrating that this domain on the alpha 1 subunit is the major anchoring site for the beta subunit.

Properties of the alpha 1-beta anchoring site in voltage-dependent Ca2+ channels.

In voltage-dependent Ca2+ channels, the beta subunit interacts with the alpha 1 subunit via a cytoplasmic site. A biochemical assay has been developed to quantitatively describe the interaction between both subunits. In vitro synthesized 35S-labeled beta subunits specifically bind to a glutathione S-transferase (GST) fusion protein containing the alpha 1A interaction domain (AIDA, located between the amino-acids 383 and 400 of the cytoplasmic loop between the hydrophobic domains I and II). Kinetic analysis demonstrates that the association of 35S-labeled beta 1b subunit to the AIDA GST fusion protein occurs with a fast rate constant at 4 degrees C. The binding is almost irreversible as demonstrated by the absence of dissociation observed after an 8-h incubation with an 18-amino acid synthetic AIDA peptide. The alpha 1-beta binding site does not seem to be a target for cytoplasmic regulation. The interaction is mostly unaffected by changes in ionic strength, pH, and Ca2+ concentration or by protein kinase C phosphorylation. The specificity of subunit interaction in voltage-dependent Ca2+ channels was also followed by saturation analyses. The data obtained show that the AIDA GST fusion protein binds to a single site on the beta 1b with an apparent Kd of 5 nM. The affinities of AIDA GST fusion protein for various beta subunits was measured and demonstrate that beta subunits associate with different affinities to each alpha 1 interaction domain. The rank order of AIDA affinity for each beta subunit is as follows: beta 4 > beta 2a > beta 1b >> beta 3. The binding of the beta subunit to alpha 1 subunit can be inhibited in vitro by the AIDA synthetic peptide with an apparent Ki of 285 nM. This interaction can also be prevented in heterologous Ca2+ channels by the injection of the AIDA GST fusion protein into Xenopus oocytes. Our results demonstrate that the site of interaction between AID and beta subunit is responsible for anchoring the beta subunit to the alpha 1 subunit and thus allowing the beta subunit to modify Ca2+ channel activity.

Ca2+ channel regulation by a conserved beta subunit domain.

The beta subunit is a cytoplasmic component that normalizes the current amplitude, kinetics, and voltage dependence of voltage-gated Ca2+ channels. Here, we identify a 30 amino acid domain of the beta subunit that is sufficient to induce a stimulation and shift in the voltage dependence of activation of the Ca2+ channel currents. This domain is located at the amino terminus of the second region of high conservation among all beta subunit gene products. Single point mutations within this region on the beta 1b subunit modified or abolished the stimulation of Ca2+ channel currents and the binding of the beta subunit to the alpha 1A subunit. The binding of this domain is also required for the observed changes in kinetics and voltage dependence of steady-state inactivation induced by beta subunits.

Calcium channel beta-subunit binds to a conserved motif in the I-II cytoplasmic linker of the alpha 1-subunit.

The beta-subunit is an integral component of purified voltage-sensitive Ca2+ channels. Modulation of Ca2+ channel activity by the beta-subunit, which includes significant increases in transmembrane current and/or changes in kinetics, is observed on coexpression of six alpha 1-subunit genes with four beta-subunit genes in all alpha 1-beta combinations tested. Recent reports suggest that this regulation is not due to targeting of the alpha 1-subunit to the plasma membrane but is probably a result of a conformational change induced by the beta-subunit. Here we report that the beta-subunit binds to the cytoplasmic linker between repeats I and II of the dihydropyridine-sensitive alpha 1-subunits from skeletal (alpha 1S) and cardiac muscles (alpha 1C-a), and also with the more distantly related neuronal alpha 1A and omega-conotoxin GVIA-sensitive alpha 1B-subunits. Sequence analysis of the beta-subunit binding site identifies a conserved motif (QQ-E--L-GY--WI--E) positioned 24 amino acids from the IS6 transmembrane domain in each alpha 1-subunit. Mutations within this motif reduce the stimulation of peak currents by the beta-subunit and alter inactivation kinetics and voltage-dependence of activation. Conservation of the beta-subunit binding motif in these functionally distinct calcium channels suggests a critical role for the I-II cytoplasmic linker of the alpha 1-subunit in channel modulation by the beta-subunit.

A beta-subunit normalizes the electrophysiological properties of a cloned N-type Ca2+ channel alpha 1-subunit.

The electrophysiological and pharmacological properties of a cloned rat brain N-type Ca2+ channel were determined by transient expression in Xenopus oocytes. Expression of the class B Ca2+ channel alpha 1 subunit, rbB-I, resulted in a high voltage-threshold current that activated slowly and showed little inactivation over 800 msec. Characteristic of N-type currents, the rbB-I current was completely blocked by omega-conotoxin GVIA and was insensitive to nifedipine and Bay K8644. The modulatory effects on the rbB-I current by cloned rat brain Ca2+ channel alpha 2 and beta 1b subunits were also examined. Coexpression of rbB-I with the beta 1b subunit caused significant changes in the properties of the rbB-I current making it more similar to N-type currents in neurons. These included: (1) an increase in the whole-cell current, (2) an increased rate of activation, (3) a shift of the voltage-dependence of inactivation to hyperpolarized potentials and (4) a pronounced inactivation of the current over 800 msec. Coexpression with the rat brain alpha 2 subunit had no significant effect on the rbB-I current alone but appeared to potentiate the rbB-I+beta 1b whole cell current. The results show that coexpression with the brain beta 1b subunit normalizes the rbB-I N-type current, and suggests the possibility that differences in subunit composition may contribute to the heterogeneous properties described for N-type channels in neurons.

Subunit identification and reconstitution of the N-type Ca2+ channel complex purified from brain.

Calcium channels play an important role in regulating various neuronal processes, including synaptic transmission and cellular plasticity. The N-type calcium channels, which are sensitive to omega-conotoxin, are involved in the control of transmitter release from neurons. A functional N-type calcium channel complex was purified from rabbit brain. The channel consists of a 230-kilodalton subunit (alpha 1B) that is tightly associated with a 160-kilodalton subunit (alpha 2 delta), a 57-kilodalton subunit (beta 3), and a 95-kilodalton glycoprotein subunit. The complex formed a functional calcium channel with the same pharmacological properties and conductance as those of the native omega-conotoxin-sensitive calcium channel in neurons.

Cloning and tissue-specific expression of the brain calcium channel beta-subunit.

A cDNA clone encoding a protein with high homology to the beta-subunit of the rabbit skeletal muscle dihydropyridine-sensitive calcium channel was isolated from a rat brain cDNA library. This rat brain beta-subunit cDNA hybridizes to a 3.4 kb message that is expressed in high levels in the cerebral hemispheres and hippocampus but is significantly reduced in cerebellum. The open reading frame encodes 597 amino acids with a predicted mass of 65 679 Da which is 82% homologous with the skeletal muscle beta-subunit. The brain cDNA encodes a unique 153 amino acid C-terminus and predicts the absence of a muscle-specific 50 amino acid internal segment. It also encodes numerous consensus phosphorylation sites suggesting a role in calcium channel regulation. The corresponding human beta-subunit gene was localized to chromosome 17. Hence the encoded brain beta-subunit, which has a primary structure highly similar to its isoform in skeletal muscle, may have a comparable role as an integral regulatory component of a neuronal calcium channel.

Estrogen induction of a small, putative K+ channel mRNA in rat uterus.

Estrogen causes dramatic long-term changes in the activity of the uterus. Here we report the molecular cloning of a small (700 base) uterine mRNA species capable of inducing a slow K+ current in Xenopus oocytes. The 130 amino acid protein encoded by this mRNA species has a predicted structure that does not resemble that of previously described voltage-dependent channels from mammalian sources. It is, however, similar to structural motifs found in certain prokaryotic ion channels. The induction of this mRNA by estrogen is rapid; this uterine mRNA species is not detectable in uteri from estrogen-deprived rats, but is substantially induced after 3 hr of estrogen treatment. These results support a critical role for regulation of ion channel expression by estrogen in the uterus.