PubMed Health⌕ Search

Biomedical subjects

G Franchi

Publications and source records attributed to G Franchi.

At least 19 recordsLinked to original sources
PubMed2006

Genetic and epigenetic changes in primary metastatic and nonmetastatic colorectal cancer.

Colorectal cancer (CRC) develops as multistep process, which involves genetic and epigenetic alterations. K-Ras, p53 and B-Raf mutations and RASSF1A, E-Cadherin and p16INK4A promoter methylation were investigated in 202 CRCs with and without lymph node and/or liver metastasis, to assess whether gene abnormalities are related to a metastogenic phenotype. K-Ras, B-Raf and p53 mutations were detected in 27, 3 and 32% of the cases, with K-Ras mutations significantly associated with metastatic tumour (P=0.019). RASSF1A, E-Cadherin and p16INK4A methylation was documented in 20, 44 and 33% of the cases with p16INK4A significantly associated with metastatic tumours (P=0.001). Overall, out of 202 tumours, 34 (17%) did not show any molecular change, 125 (62%) had one or two and 43 (21%) three or more. Primary but yet metastatic CRCs were prevalent in the latter group (P=0.023) where the most frequent combination was one genetic (K-Ras in particular) and two epigenetic alterations. In conclusion, this analysis provided to detect some molecular differences between primary metastatic and nonmetastatic CRCs, with K-Ras and p16INK4A statistically altered in metastatic tumours; particular gene combinations, such as coincidental K-Ras mutation with two methylated genes are associated to a metastogenic phenotype.

Aged↗
PubMed2005

[Scalp surgery in children: principles and therapeutic aspects].

Surgical treatment of the lesions of the scalp in children has specific objectives: excision of an extensive lesion using minimum operative procedures, hiding scar in the hair, correcting a wide and ungraceful scar. We reviewed our experience of 450 cases (1990-2000), and found that most common lesions in childhood were: sebaceous hamartoma, pigmentary naevus, post traumatic alopecia, aplasia cutis congenita and complicated hemangiomas. Different surgical procedures are discussed: excision, tissue expansion, hair grafts. Large excision can be performed before three months of life because of the good laxity of the scalp. Tissue expansion is particularly suited to the scalp. Aplasia cutis congenita is a special condition, with local vascular abnormalities: local flaps are prohibited. Hemangiomas may require early surgical treatment in the event of complications.

Adolescent↗
PubMed2004

Time course for the reappearance of vibrissal motor representation following botulinum toxin injection into the vibrissal pad of the adult rat.

The present study investigates the time course and pattern of movement representation recovery in the motor cortex during the recovery after a peripheral paralysis. To this end a transitory flaccid paralysis of the vibrissae muscle was induced in adult rats that underwent two unilateral injections of 8 U of botulinum toxin (BTX) into a vibrissal pad, at a duration of 12 days from one another. The compound muscle action potential (MAP) of the vibrissae muscle began to reappear 4 weeks after the first BTX injection. Intracortical microstimulation (ICMS) was used to map rat motor cortices 4, 5, 6, 7 and 8 weeks after the first BTX injection. Findings demonstrated that: (i) contralateral vibrissae movement reappears in the medial part of its normal cortical territory when the MAP is almost 10% of the control value; in the remaining part, ICMS elicits eye, ipsilateral vibrissae, neck and forelimb movements; (ii) the contralateral vibrissae movement reappears in sites where ipsilateral vibrissae and/or neck movement are co-represented; (iii) as MAP recovers, the vibrissae representation expands until it recovers the 90.8% of its territory after 7 weeks, when the MAP was almost 43.4% of the control value; (iv) from 4 to 7 weeks, the ICMS-evoked contralateral vibrissae movement shows a significantly higher electrical threshold vs. the control group; (v) recovery of the baseline excitability uniformly involves the vibrissae representation 1 week later, after its cortical territory has recovered 93.1% of the control value and the MAP has returned to 78.8% of the baseline value.

Action Potentials↗
PubMed2002

Time course of motor cortex reorganization following botulinum toxin injection into the vibrissal pad of the adult rat.

The present experiment studies representation patterns in the motor cortex (M1) of adult rats, 1, 3, 6, and 12 days after unilateral injection of Botulinum Toxin (BTX) into the vibrissa pad. Intracortical microstimulation (ICMS) was used to evidence changes in the representation over time and in the current thresholds required to evoke movements inside the disconnected vibrissa region. After 1 day, isolated as well as contiguous negative sites were observed within the motor cortex corresponding to the disconnected vibrissa region. Thereafter the percentage of unresponsive sites decreased so that after 6 days, the number of unresponsive sites was not significantly higher than those in the control hemispheres. Within the disconnected vibrissa region, electrical stimulation elicited forelimb, eye, ipsilateral vibrissa and neck movements. Following BTX injection, the enlargement of the forelimb representation into the disconnected vibrissa representation began during the first day and stabilized during the second week after injection. In the first days, stimulation thresholds in expanded forelimb sites were higher than those required for similar movement in normal M1 forelimb representation. These thresholds then declined so that in approximately 6 days they were similar to normal. There was no clear evidence that stimulation of sites in the medial part of disconnected vibrissa-cortex evoked eye movements during the first 6 days after BTX injection. After this time, thresholds required to evoke eye movement in expanded sites were generally similar to, and never higher than, those needed to evoke this movement in control sites. Intermingled ipsilateral vibrissa and neck movement occupies part of the medial vibrissa region. Over the 12 days, extension of the ipsilateral vibrissa representation shrank while the representation of neck movement remained unchanged. Throughout the entire time there was no change in the excitability of these sites and the thresholds remained higher than that needed to elicit the vibrissa movement normally represented in this cortical region. No significant differences in threshold were found over time for any of the other movement categories represented in M1. These results indicate that, over time, the new movements inside the disconnected vibrissa region develop differently in M1 following peripheral motor disconnection. The implications for mechanisms involved in cortical plasticity are discussed.

Animals↗
PubMed2002

Rehabilitation of the paralysed or lax lower eyelid using a graft of conchal cartilage.

Excessive laxity of the tarso-ligamentous sling of the lower eyelid may be caused by inadequate muscular support (resulting from injury to the muscle, facial palsy or senile degeneration) or prolonged mechanical distension (exophthalmia). Numerous techniques have been devised for functional reconstruction of the distended lower eyelid, based upon the principle that restoring the lower eyelid to its anatomical position will improve lacrimal transit andre-establish its natural protective function. We now use an autologous conchal cartilage graft to treat the distended or atonic lower eyelid. We review our results in a retrospective study of 20 patients, and aim to identify the indications for this procedure and to evaluate its advantages and disadvantages relative to other existing methods. All of our patients reported functional improvement after the operation in terms of decreased dry-eye symptoms, less epiphora and a decline in keratitis and conjunctivitis. All patients also reported a visible cosmetic improvement postoperatively. The major drawback of this operation is the partial loss of the visual field when looking down, due to the limited lowering of the lower eyelid. The stability of our results compares favourably with that achieved using other currently available techniques. We conclude that autologous conchal cartilage grafting is an effective procedure for improving both the function and the appearance of the atonic lower eyelid.

Adult↗
PubMed2002

Melanotic neuroectodermal tumour of infancy involving the orbit and maxilla: surgical management and follow-up strategy.

Melanotic neuroectodermal tumour (MNET) of infancy is a rare benign but locally aggressive tumour. We describe our surgical treatment of MNET of the orbital region. There was osteogenic relapse involving the bone of the orbit, 20 days after macroscopically complete excision of the primary tumour when the patient was 12 weeks old. This is only the second report of osteogenic relapse in MNET. The relapse was treated by excision of the involved orbital floor, preserving the orbital periosteum. The tumour has not recurred in 23 months of follow-up. Residual tumour islets may regress spontaneously after incomplete excision of MNET, but the relapse rate is between 15% and 45%. In our opinion, excising a safety margin of a few mm of apparently healthy bone reduces the risk of relapse. In contrast, the orbital contents should be preserved if they are macroscopically normal. Follow-up consisted of frequent physical examinations and CT scans.

Humans↗
PubMed2001

Persistence of vibrissal motor representation following vibrissal pad deafferentation in adult rats.

The effect of sensory vibrissal pad denervation on M1 organization was studied in adult rats 2 weeks after the infraorbital nerve was severed. Cortical motor output organization was assessed mapping the representation size and thresholds of vibrissa movements evoked by intracortical electrical microstimulation (ICMS). Motor cortex output patterns of control and sham groups of rats were compared with those of rats that had received unilateral or bilateral infraorbital nerve lesions. The mean size of the vibrissa representation in both unilateral and bilateral input-deprived hemispheres was not significantly different from those in control and sham hemispheres. The mean threshold required to evoke vibrissa movements was significantly higher in both groups of deafferented hemispheres than in control and sham groups of hemispheres. In contrast, the mean threshold required to evoke other types of movements from both groups of input-deprived hemispheres were similar to those found in the control and sham groups of hemispheres. These results indicate that input-deprived vibrissal motor representation reflects lower-than-normal excitability, although the size and topographic relationship with neighboring representations are normal.

Afferent Pathways↗
PubMed2000

Changes in motor representation related to facial nerve damage and regeneration in adult rats.

The present study examined how facial nerve regeneration shapes movement representation patterns in previously disconnected motor cortices. Electrical microstimulation was used to bilaterally map the motor cortices of adult rats subjected to unilateral facial nerve lesion and reanastomosis stamps at the stylomastoid foramen level. The motor cortex output patterns of two groups of experimental hemispheres (contralateral to lesioned side) were compared before and after facial nerve reinnervation. The motor cortex output patterns in the control hemispheres (ipsilateral to the lesioned side) were used as reference. Before facial nerve reinnervation, the motor cortex forelimb and eye output area extended into the vibrissa area; such enlargement did not occupy the medial part of the former vibrissa area where ipsilateral vibrissa or neck movements were represented. After facial nerve reinnervation, the contralateral vibrissa movement reorganized into a shrunken cortical area corresponding to the medial portion of the former vibrissa representation, i.e., where the ipsilateral vibrissa and neck movements were mainly represented prior to facial nerve reinnervation. The enlargement of the forelimb and eye representation remained unchanged, even after the vibrissa motor innervation was reactivated. Before facial nerve reinnervation into expanded forelimb and eye representations, a minimal current was required to evoke these movements, which did not vary from the normal range. A higher current was necessary to evoke the ipsilateral vibrissa and neck movements in the medial part of the vibrissa representation than the threshold needed to elicit the vibrissa movement normally represented in this cortical region. After facial nerve reinnervation, the overall current required to evoke movement remained the same as that which evoked movement before the vibrissa motor innervation was reactivated.

Action Potentials↗
PubMed2000

Reorganization of vibrissal motor representation following severing and repair of the facial nerve in adult rats.

This study examined the ability of adult rat motor cortex to reorganize its relationship with the somatic musculature following the severing and regeneration of a motor nerve. For this purpose experiments were performed on ten male albino rats where the facial nerve on one side was severed, sutured and allowed to regenerate for 6 months. Cortical motor output organization was assessed by mapping the vibrissal movement area extension and thresholds evoked by intracortical electrical stimulation in anesthetized rats. In all ten animals, the cortical output pattern of the motor cortex contralateral to the normal side was compared with that contralateral to the reinnervated side. After facial nerve reinnervation, the most notable differences in primary motor cortex (M1) output organization in the hemispheres contralateral to the reinnervated side were: (a) the area from which vibrissa movements could be evoked at low thresholds was smaller (mean 1.2+/-0.38 mm, range 0.75-1.75 mm), decreasing to 64.2% below those in hemispheres contralateral to the normal side (mean 3.4+/-0.52 mm, range 2.5-4 mm). The reorganized vibrissa area consisted of contiguous or discontinuous points shrunken to the medialmost portion of normal M1 vibrissal representation. (b) There was a clear medial extension of the forelimb representation, and a more modest lateral expansion of eye representation, into the vibrissa territory. The mean threshold required to evoke vibrissa movements was significantly higher in the hemispheres contralateral to the reinnervated side than in the other hemispheres (normal 23.9+/-9.7 microA vs reinnervated 37.8+/-11.9 microA; P< or =0.0001; t-test). The stimulation currents required to evoke other types of body movements were similar in the normal and reinnervated sides. Similar results were observed in all rats. In conclusion, these results indicate that motor nerve reinnervation is sufficient to produce long-lasting changes at a higher motor cortical level. This supports the notion that central supranuclear mechanisms may also be involved in the disorder of facial movements observed after facial nerve reinnervation.

Animals↗
PubMed2000

A computerized guideline for pressure ulcer prevention.

This paper illustrates the implementation of a computerized guideline for pressure ulcer prevention. In particular, it describes the aspects related to the site-specification of a guideline delivered by the Agency for Health Care Policy Research (AHCPR), to its integration with the electronic patient record, and to its implementation within the clinical routine. The primary goal of the system is both to facilitate nurses assessing the risk of ulcer development, and to manage patients at risk by producing daily prevention work-plans. Concerning this functionality, particular attention has been paid to manage nurse's non-compliance with the guideline suggestions and to collect data for evaluating the guideline impact. Moreover, since it is well known that nurses are often over-loaded, the human computer interaction has been studied in such a way to optimise the time spent for data input. An additional functionality of the system is the novice nurses' education - they can browse a graphical representation of the guideline, asking details about the different tasks, and they can simulate patients to obtain real-time advice. The educational tool is written in Java and it is based on a representation of the guideline as a relational database. A preliminary evaluation of the system has been performed and the results are presented on the management of about 40 patients.

Decision Support Systems, Clinical↗
PubMed1999

Visual responses in the dorsal premotor area F2 of the macaque monkey.

This study aimed to determine the presence of neurons responding to visual stimuli in area F2 of the dorsal premotor cortex of the macaque monkey. In order to delimit the sector in which visually responsive neurons are located, the somatotopic organization of area F2 was studied with intracortical microstimulation and single neuron recording. The results showed that: (1) in area F2 there is a significant percentage of visually responsive neurons (15.9% of all recorded neurons); (2) area F2 is excitable with a low-threshold current (average 28.1 microA) and has a somatotopic representation of the whole body, except the face; and (3) most visually driven neurons (n=130 out of 169) are concentrated within the rostrolateral sector of the forelimb representation of area F2, thus providing for the first time functional support for the neuroanatomical evidence that the visual input to area F2 is mostly restricted to this sector.

Animals↗
PubMed1999

[Circumscribed mandibular osteitis in children due to hematogenous dissemination. Apropos of 5 clinical cases].

In children, mandibular swelling associated with an X-ray bone osteolysis may correspond to tumoral or infection diseases. Circumscribed osteitis of a child's mandibula, with no dental etiology occurs around 7-years of age, adjacent to a healthy first molar. Five cases reports were analyzed. Clinically, it is a bone swelling of the mandibula's lateral cortical associated with a soft tissue swelling. X-ray signs were not specific but all cases showed a bone lacuna with sharp outlines. Such clinical and X-ray signs strongly suggest diagnosis of osteitis which has a higher incidence than malignant tumors. The lack of dental pathology suggests bloodstream dissemination from another localized sepsis. Surgical removal of pathologic bone in addition to antibiotics (6 or 8 weeks) appears to be an effective treatment.

Amoxicillin↗
PubMed1999

A computerised guideline for pressure ulcer prevention.

This work illustrates the implementation of a computerised guideline for the pressure ulcers prevention. In particular, we describe the site-specification of a guideline delivered by the Agency for Health Care Policy Research, its integration with the electronic patient record, and its introduction within the clinical routine. The system facilitates trained nurses in the patient management by producing daily workplans, and novice nurses by running as an educational tool.

Humans↗
PubMed1998

Experience of hepatitis A vaccination during an outbreak in a nursery school of Tuscany, Italy.

An outbreak of hepatitis A started in late October 1996 in a nursery school in Tuscany, Italy. A programme of hepatitis A vaccination without the use of immunoglobulin started at the beginning of December 1996 and included 33 children, 21 household contacts and 6 adults working in the school. Overall, 11 cases occurred in children attending the school (attack rate 27%) and 10 among their household contacts (attack rate 9 %). The latter also included parents, and, in two cases, grandmothers. The data indicate that susceptibility to HAV has increased over recent decades in central Italy. Past and recent experience shows that the usual duration of hepatitis A epidemics in the absence of immune prophylaxis is longer than that described here. The use of hepatitis A vaccine probably contributed to the early extinction of the outbreak, because no further cases were notified in the area after 7 February 1997.

Adult↗
PubMed1998

[Sagittal osteotomy of the ascending ramus. Technic and value of transcutaneous basilar osteotomy].

Dalpont II sagittal osteotomy is the procedure of choice for prognathism. The surface for bone consolidation can be significantly increased by an anterior extension of the section, favored in cases with major skeletal imbalance. Neurosensorial or bone complications often compromise sagittal surgery. Section may be difficult if the basilary bone is particularly solid; simple section is not entirely satisfactory due to the risk and is not well adapted to Dalpont II osteotomy. We present a novel technique for transcutaneous basilar osteotomy using a modified transjugal retractor and a mini saw blade. This technique gives a Dalpont II sagittal osteotomy with a long reproducible and safe valve.

Bone Plates↗
PubMed1998

[Intraluminal absorbable device to assist in vascular microanastomosis. Experimental study on 20 rat aortas].

The subject of this experimental study is a cylindrical device, with a gauge adjusted to the vessel lumen, which disintegrates in a few minutes. The goal of this device is to increase the reliability of vascular microanastomosis. This study was designed to assess the efficacy and drawbacks of the device. The device is a cylindrical sugar stick, 5 mm long and with a gauge of 1 mm. Ten Wistar rats underwent a standard end-to-end aortic anastomosis with interrupted sutures and ten underwent the same anastomosis with the device placed in the lumen of the proximal and distal vessel. The same surgeon performed all anastomoses. Clamp application time was recorded and anastomotic patency was tested in each case; the vessels were also examined histologically. The clamp application time was significantly lower (p < 0.01), and the patency rate significantly higher (p < 0.01) in the group in which the device was used. There was no histologic sign of intima injury in either group. This very simple device facilitates microanastomosis. It reduces the ischemia time and increases the reliability of the anastomosis, avoiding transfixing sutures. These results suggest that clinical trials are warranted.

Anastomosis, Surgical↗