Biomedical subjects

C Alfano

Publications and source records attributed to C Alfano.

At least 19 recordsLinked to original sources

PubMed2006

Use of the reverse flow island sural flap in the replacement of tissue loss involving the distal third of the leg, ankle and heel.

The events leading to a tissue loss in the lower limbs are varied. The aetiology can be traumatic, infective, neoplastic, iatrogenic, vascular or systemic. Five patients with lesions involving the distal third of the lower limb, the ankle and the heel, traumatic in origin, presented at our service within the Faculty of Plastic and Reconstructive Surgery, University Hospital "La Sapienza" in Rome. In such patients, the surgical approach involved the repair of tissue loss through the use of the neurocutaneous distally based sural artery flap. The use of the reverse flow island sural flap, compared to other therapeutic options, is advantageous from varying points of view: ease in taking the sample, limited morbidity of the donator site, less time required for the surgical procedure. Regarding the flap, safety and simplicity of execution were implemented in accordance with our experience, dissecting a wide adipo-fascial peduncle. Post-operative precautions were implemented in order to avoid compression of the transposed flap and of the peduncle. The healing in these patients was satisfactory.

Adult↗

PubMed2006

Ear reconstruction after cancer excision.

Cancers which involve the external ear are difficult to eradicate and recur and develop metastases more often than tumours in other areas of the skin. The anatomy of the external ear presents a difficult reconstructive challenge so that various surgical techniques have been described for its reconstruction, but many of these are complex procedures and are inappropriate in the older population suffering from skin tumours. We carried out a retrospective study of the patient who underwent ear reconstruction after cancer excision analyzing the data concerning the type of cancer, the surgical procedures and the follow up. We conclude that all major defects involving one-quarter or more of the auricle can be repaired with a combination of skin flaps and a chondrocutaneous flap from the affected auricle. Sentinel node biopsy may be a useful tool in diagnosing early lymphatic spread.

Adult↗

PubMed2006

The use of laser and Varioscope in the management of hemangiomas and vascular malformations.

Vascular lesions are common in infants and children and can be grouped into two main classifications: vascular tumors and vascular malformations. Hemangiomas are proliferative lesions characterized by increased endothelial cell turnover. Vascular malformations are congenital abnormalities involving capillaries, veins and/or lymphatics. A multidisciplinary approach regarding diagnosis and treatment of vascular anomalies in children is crucial. Several options are available for the treatment of hemangiomas. Since January 2003, 14 cases of hemangioma located in the cervicofacial region were treated at "La Sapienza" University. Seven patients underwent surgical resection, using Varioscope, and seven laser therapy. The Varioscope is an operating microscope, which is mounted on the head. Specific advantages convinced the authors to use the Varioscope initially. Autofocus, a magnification range between 3.6-7.2X and automatic parallax control allow unlimited freedom of movement which alleviates the discomfort of keeping the same distance for a long time. Laser therapy can selectively destroy specific targets within the skin by using an appropriate wavelength and pulse duration. Laser treatment parameters are based on several factors, including lesion location, lesion morphology, and patient skin type. The purpose of our study was aesthetic and functional improvement in patients comparing surgical and laser therapy. We obtained an aesthetic improvement in 11 patients and local pain control in all patients. Analysis of the cosmetic results was subjective but all parents indicated satisfaction with their decision regarding their child's treatment.

Arteriovenous Malformations↗

PubMed2006

Lateral canthoplasty--10-year experience.

Lateral canthoplasty is a useful method to restore eyelid function and to protect the ocular surfaces. The success of the procedure depends on the proper analysis of periorbital anatomy as it relates to the specific indication for lateral canthoplasty. We report the experience with 129 lateral canthoplasties with emphasis on the evaluation of newer techniques that better address anatomic and functional requirements. Between 1994 and 2004, 129 lateral canthoplasties were performed in 105 patients, only for reconstructive purpose. A variety of surgical techniques have been described for lateral canthoplasty, and the evolution of the operative technique for lateral canthoplasty has been toward an operation that corresponds with the anatomy of the individual. Indications for the procedure include senile ectropion, tumors, cicatritial retraction, trauma, entropion, and congenital cleft. The evaluation of the newer procedures of lateral canthoplasty as unique reconstructive tools will be discussed.

Blepharoplasty↗

PubMed2005

Versatility of the hatchet flap in facial reconstruction.

The hatchet flap, well known for repair of the nasal pyramid, laterofacial defects and pressure sores, is used to reconstruct different aesthetic units of the face. The authors describe the surgical technique and its clinical applications to the different face subunits in 38 patients, highlighting the easy learning curve, the versatility of the flap and the good aesthetic results when the principles of the facial units are respected. No previous detailed report has been described in the literature.

Aged↗

PubMed2005

[An alternative to the usual operating microscope and loupe magnification for free microvascular tissue transfer. Varioscope AF3-A].

AIM: Free microvascular tissue transfers have become today a key instrument for the surgical treatment of wide loss of tissue, but their employment implies mandatory use of the right visual magnification means. Until now these instruments were mainly loupes and operating microscopes. Our study is focusing on the use of a new visual system--Varioscope AF3-A--in the reconstructive microsurgery field. METHODS: Varioscope AF3-A (Life Optics, Vienna, Austria) has been employed in our Institute in 10 microvascular reconstructions, where different free flaps were used in head and neck reconstruction. RESULTS: All the flaps took and only one developed a partial necrosis. We have also noticed, by using this new instrument, a learning curve with a progressive contraction of the operating time. In all cases we have operated on 2 mm caliber vessels or more and on tissues that didn't previously undergo radiation therapy. CONCLUSIONS: The employment of a visual magnification mean, as Varioscope AF3-A, allows autofocus (from 3.6X to 7.2X) and a wide vision. It can be easily used with substantial advantages for the surgeon in performing microvascular anastomosis. Partial drawbacks are the equipment high cost and weight, compared to the loupes and a stronger ocular stress due to the continuous autofocus compared to the static operating microscopes.

Humans↗

PubMed2004

Treatment of non-melanoma skin cancer in North Sardinia: is there a need for biopsy?

UNLABELLED: Non-melanoma skin cancer (NMSC) is the most common type of skin cancer. Important controversial issues are the need for incisional biopsies, surgical margin, and timing of follow-up. METHODS: A retrospective study was undertaken on 2544 lesions. Accuracy of diagnosis and prevalence of incomplete excision were evaluated, comparing clinical and histological diagnosis using chi2 tests with Yates' correction. Kaplan-Meier recurrence graphs have been obtained. RESULTS: Lesions were correctly diagnosed in 94% of basal cell carcinomas (BCC) and in 69% of squamous cell carcinomas (SCC) (p < 0.001). Positive margins on pathological examination were 6.6% for BCC and 6.8% for SCC. A significant difference for incomplete excision has been found for BCC in the face (p < 0.001). Kaplan-Meier survival curves showed a different pattern for BCC and SCC. CONCLUSIONS: On the basis of our data, if clinical diagnosis is BCC, excision and reconstruction may be undertaken without an incisional biopsy. Alternatively, if clinical diagnosis is SCC, it is advisable to consider an incisional biopsy, before definitive surgical treatment.

Adult↗

PubMed2004

Nipple reconstruction by local flaps: a long-term comparative study between star and skate techniques.

Nipple reconstruction often gives the highest satisfaction to the patient despite being just a minor procedure. During the last 50 years, many techniques have been described in order to improve the cosmetic appearance. Star and skate flaps are two of the most frequently reported procedures. The aim of this study was to compare the personal experience of two plastic surgery departments that have been using these two different methods. Thirty patients have been included in this study. Nipple projection and cosmetic appearance have been evaluated by both patients and surgeons. Follow-up ranged between 1 and 5 years. Results have been compared. Both techniques proved to be versatile and valid. The skate flap seemed to keep projection for a longer time, while the star technique gave a better cosmetic appearance.

Esthetics↗

PubMed2002

[Professional autonomy in the choice and management of therapy. Medicolegal aspects].

Any discussion of the delicate subject of a doctor's autonomy in the choice and management of therapy entails addressing the intimate question of professional and ethical conduct. The professional freedom to choose which therapy to use continues to be the most quintessential expression of the medical professional and, in respect of the primary purpose of safeguarding health, must be aligned with: the choices of the informed patient or his/her legal representatives, existing guidelines and the equitable allocation of resources. On these grounds, the author sets out brief considerations regarding a number of issues frequently raised in the everyday work of the pediatrician and neonatologist: from the doctor's autonomy to adopt a diagnostic-therapeutic approach, with special reference to the prescription of drugs and the subtle differences compared to pharmacological trials, to the promotion and protection of breastfeeding, with explicit reference to the Ministry of Health's recent Circular no. 16 of 24.10.2000 ("Promotion and protection of breastfeeding") which, following a cursory reading of the text, appears to highlight restrictions to the pediatrician's decision-making autonomy. Special emphasis is also given to the medicolegal problems of caring for high-risk neonates. The clinical practice of neonatology often places the doctor in "critical" decision-making situations, with far from negligible ethical and moral implications, not to mention juridical and forensic ones. The author sets out a number of decision-making parameters for use as guidelines: the statistical criterion, the legal criterion and the clinical criterion, the only one capable of adjusting to scientific progress and to the specific technical and professional resources of the medical centre where the doctor is required to intervene in order to preserve even the simple "possibility" of autonomous life for the fetus. From this point of view, the so-called chronological vitality and scientifically proven statistics form part of the numerous criteria available for clinical evaluation. If the clinical criterion is not met, namely if the product of conception is not vital and has never been fully alive in the biologically complete sense of the term, then the omission of therapeutic support is not particularly important in professional and juridical terms. On the contrary, it would show an obstinate persistence of therapy, which would be both ethically and professionally incorrect. Lastly, even during the final stages of life, the doctor must play a participatory role not only by providing palliative treatment but also, and above all, offering moral assistance to sanction the ineluctable end of the therapeutic alliance, that "feeling together" which is the most literal and profound meaning of the word "consent", indicating both "information" but to an even greater extent "discussion" and "empathy" with the patient and his/her family.

Breast Feeding↗

PubMed2001

Congenital defect in the abdominal wall in an adult: a case report.

We describe a rare case of a woman aged 38 who presented with an untreated omphalocele in association with a duplication of the vena cava and malposition of the right kidney. An aesthetic and functional reconstruction of the abdomen was achieved with local flaps and the creation of a neoumbilicus.

Abdominal Muscles↗

PubMed1994

Reconstruction of the lower lip with a full thickness nasolabial island flap.

We have used a full thickness nasolabial island flap to reconstruct the lower lip after excision of its median or paramedian part for carcinoma in 12 patients. The flap is transposed through a subcutaneous tunnel over the modiolus without interrupting the muscle fibres of the commissura. All the patients were men who smoked, with a mean age of 64 years, and they have been followed up for a mean of 18 months (range 6-36). Functional and aesthetic results were good in all cases; there have been no recurrences or lymph node metastases, and the only postoperative complications were two cases of superficial necrosis of the distal part of the flap which healed spontaneously without scarring. We think that the full thickness nasolabial island flap is a satisfactory technique for reconstruction of the lower lip.

Carcinoma, Squamous Cell↗

PubMed1994

[A comparison between propafenone and amiodarone in the conversion to sinus rhythm of atrial fibrillation of recent onset].

The effectiveness of propafenone versus amiodarone for conversion to sinus rhythm of paroxysmal atrial fibrillation was compared. Fifty-four consecutive adult patients affected by recent onset atrial fibrillation (< 7 days) were randomized to treatment with intravenous propafenone (27 patients) and amiodarone (27 patient). Sinus rhythm was restored respectively in 74.1% and 70.4% (p = ns); within 5 hours was obtained reconversion in 65% of propafenone and in 15.8% of amiodarone group (p < 0.05); the mean conversion time was 3.5 and 16.6 hours (p < 0.01). In conclusion propafenone seems to be as effective and safe as amiodarone, but is significantly fast in converting recent onset atrial fibrillation to sinus rhythm.

Adult↗

PubMed1990

Host virus interactions in the initiation of bacteriophage lambda DNA replication. Recruitment of Escherichia coli DnaB helicase by lambda P replication protein.

The bacteriophage lambda P protein promoters replication of the phage chromosome by recruiting a key component of the cellular replication machinery to the viral origin. Specifically, P protein delivers one or more molecules of Escherichia coli DnaB helicase to a nucleoprotein structure formed by the lambda O initiator at the lambda replication origin. Using purified proteins, we have examined the features of the pivotal host virus interaction between P and DnaB. These two proteins interact in vitro to form a P.DnaB protein complex that can be resolved by sedimentation or by chromatography on DEAE-cellulose from the individual free proteins. The sedimentation coefficient of the P.DnaB complex, 13 S, suggests a size larger than that of free DnaB hexamer (Mr = 313,600). The P.DnaB complex isolated by glycerol gradient sedimentation contains approximately three protomers of P/DnaB hexamer, consistent with a molecular weight of 393,000. The isolated P.DnaB complex functions in vitro in the initiation of lambda DNA replication. Interaction of P with DnaB strongly suppressed both the intrinsic DNA-dependent ATPase activity of DnaB, as well as the capacity of DnaB to assist E. coli primase in the general priming reaction. Formation of a P.DnaB protein complex also blocked DnaB from functioning in the initiation of E. coli DNA replication in vitro. The physical and functional properties of lambda P protein suggest that it is a viral analogue of the E. coli DnaC replication protein. Like P, DnaC also binds to DnaB (Wickner, S., and Hurwitz, J. (1975) Proc. Natl. Acad. Sci. U. S. A. 72, 921-925), but unlike P, DnaC stimulates DnaB-mediated general priming. When viral P and bacterial DnaC replication proteins were placed in direct competition with one another for binding to DnaB, the viral protein was clearly predominant. For example, a 5-fold molar excess of DnaC protein only partially reversed the inhibitory effect of P on general priming. Furthermore, when a preformed DnaC.DnaB protein complex was incubated briefly with P protein, it was readily converted into a P.DnaB protein complex and the bulk of the bound DnaC was released as free protein. It is likely that the capacity of the lambda P protein to outcompete the analogous host protein for binding to the bacterial DnaB helicase is the critical molecular event enabling infecting phage to recruit cellular replication proteins required for initiation of DNA synthesis at the viral origin.

Bacterial Proteins↗

PubMed1989

Ordered assembly of nucleoprotein structures at the bacteriophage lambda replication origin during the initiation of DNA replication.

Replication of the chromosome of bacteriophage lambda depends on the cooperative action of two phage-coded proteins and seven replication and heat shock proteins from its Escherichia coli host. As previously described, the first stage in this process is the binding of multiple copies of the lambda O initiator to the lambda replication origin (ori lambda) to form the nucleosomelike O-some. The O-some serves to localize subsequent protein-protein and protein-DNA interactions involved in the initiation of lambda DNA replication to ori lambda. To study these interactions, we have developed a sensitive immunoblotting protocol that permits the protein constituents of complex nucleoprotein structures to be identified. Using this approach, we have defined a series of sequential protein assembly and protein disassembly events that occur at ori lambda during the initiation of lambda DNA replication. A second-stage ori lambda.O (lambda O protein).P (lambda P protein).DnaB nucleoprotein structure is formed when O, P, and E. coli DnaB helicase are incubated with ori lambda DNA. In a third-stage reaction the E. coli DnaJ heat shock protein specifically binds to the second-stage structure to form an ori lambda.O.P.DnaB.DnaJ complex. Each of the nucleoprotein structures formed in the first three stages was isolated and shown to be a physiological intermediate in the initiation of lambda DNA replication. The E. coli DnaK heat shock protein can bind to any of these early stage nucleoprotein structures, and in a fourth-stage reaction a complete ori lambda.O.P.DnaB.DnaJ.DnaK initiation complex is assembled. Addition of ATP to the reaction enables the DnaK and DnaJ heat shock proteins to mediate a partial disassembly of the fourth-stage complex. These protein disassembly reactions activate the intrinsic helicase activity of DnaB and result in localized unwinding of the ori lambda template. The protein disassembly reactions are described in the accompanying articles.

Bacteriophage lambda↗

PubMed1989

Heat shock protein-mediated disassembly of nucleoprotein structures is required for the initiation of bacteriophage lambda DNA replication.

Three Escherichia coli heat shock proteins, DnaJ, DnaK, and GrpE, are required for replication of the bacteriophage lambda chromosome in vivo. We show that the GrpE heat shock protein is not required for initiation of lambda DNA replication in vitro when the concentration of DnaK is sufficiently high. GrpE does, however, greatly potentiate the action of DnaK in the initiation process when the DnaK concentration is reduced to a subsaturating level. We demonstrate in the accompanying articles (Alfano, C. and McMacken, R. (1989) J. Biol. Chem. 264, 10699-10708; Dodson, M., McMacken, R., and Echols, H. (1989) J. Biol. Chem. 264, 10719-10725) that DnaJ and DnaK bind to prepriming nucleoprotein structures that are assembled at the lambda replication origin (ori lambda). Binding of DnaJ and DnaK completes the ordered assembly of an ori lambda initiation complex that also contains the lambda O and P initiators and the E. coli DnaB helicase. With the addition of ATP, the DnaJ and DnaK heat shock proteins mediate the partial disassembly of the initiation complex, and the P and DnaJ proteins are largely removed from the template. Concomitantly, on supercoiled ori lambda plasmid templates, the intrinsic helicase activity of DnaB is activated and DnaB initiates localized unwinding of the DNA duplex, thereby preparing the template for priming and DNA chain elongation. We infer from our results that DnaK and DnaJ function in normal E. coli metabolism to promote ATP-dependent protein unfolding and disassembly reactions. We also provide evidence that neither the lambda O and P initiators nor the E. coli DnaJ and DnaK heat shock proteins play a direct role in the propagation of lambda replication forks in vitro.

Bacterial Proteins↗

PubMed1989

Reconstitution of a nine-protein system that initiates bacteriophage lambda DNA replication.

We have established an in vitro system, composed of highly purified bacteriophage lambda and Escherichia coli proteins, that specifically replicates supercoiled templates bearing the lambda replication origin (ori lambda). The complete system is composed of three groups of proteins: the virus-encoded initiator proteins (the lambda O and P proteins), the E. coli replication fork propagation machinery (single-stranded DNA-binding protein, dnaB helicase, dnaG primase, DNA polymerase III holoenzyme, and DNA gyrase), and two bacterial heat shock proteins (dnaJ and dnaK proteins). DNA replication in this system is initiated at or near ori lambda and proceeds unidirectionally rightwards through theta-structure intermediates, ultimately yielding a pair of intertwined daughter circles as the final product. In striking contrast to the situation in vivo and in crude in vitro systems, initiation of lambda DNA replication in the purified protein system does not require "transcriptional activation" of the origin region by E. coli RNA polymerase. We conclude that E. coli primase generates the primers for all leading and lagging strand DNA chains synthesized in this reconstituted lambda replication system.

Bacterial Proteins↗

PubMed1988

The role of template superhelicity in the initiation of bacteriophage lambda DNA replication.

The prepriming steps in the initiation of bacteriophage lambda DNA replication depend on the action of the lambda O and P proteins and on the DnaB helicase, single-stranded DNA binding protein (SSB), and DnaJ and DnaK heat shock proteins of the E. coli host. The binding of multiple copies of the lambda O protein to the phage replication origin (ori lambda) initiates the ordered assembly of a series of nucleoprotein structures that form at ori lambda prior to DNA unwinding, priming and DNA synthesis steps. Since the initiation of lambda DNA replication is known to occur only on supercoiled templates in vivo and in vitro, we examined how the early steps in lambda DNA replication are influenced by superhelical tension. All initiation complexes formed prior to helicase-mediated DNA-unwinding form with high efficiency on relaxed ori lambda DNA. Nonetheless, the DNA templates in these structures must be negatively supertwisted before they can be replicated. Once DNA helicase unwinding is initiated at ori lambda, however, later steps in lambda DNA replication proceed efficiently in the absence of superhelical tension. We conclude that supercoiling is required during the initiation of lambda DNA replication to facilitate entry of a DNA helicase, presumably the DnaB protein, between the DNA strands.

Bacteriophage lambda↗

PubMed1986

Specialized nucleoprotein structures at the origin of replication of bacteriophage lambda: localized unwinding of duplex DNA by a six-protein reaction.

The O protein of bacteriophage lambda localizes the initiation of DNA replication to a unique site on the lambda genome, ori lambda. By means of electron microscopy, we infer that the binding of O to ori lambda initiates a series of protein addition and transfer reactions that culminate in localized unwinding of the origin DNA, generating a prepriming structure for the initiation of DNA replication. We can define three stages of this prepriming reaction, the first two of which we have characterized previously. First, dimeric O protein binds to multiple DNA binding sites and self-associates to form a nucleoprotein structure, the O-some. Second, lambda P and host DnaB proteins interact with the O-some to generate a larger complex that includes additional DNA from an A + T-rich region adjacent to the O binding sites. Third, the addition of the DnaJ, DnaK, and Ssb proteins and ATP results in an origin-specific unwinding reaction, probably catalyzed by the helicase activity of DnaB. The unwinding reaction is unidirectional, proceeding "rightward" from the origin. The minimal DNA sequence competent for unwinding consists of two O binding sites and the adjacent A + T-rich region to the right of the binding sites. We conclude that the lambda O protein localizes and initiates a six-protein sequential reaction responsible for but preceding the precise initiation of DNA replication. Specialized nucleoprotein structures similar to the O-some may be a general feature of DNA transactions requiring extraordinary precision in localization and control.

Adenosine Triphosphate↗