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Biomedical subjects

R Salvador

Publications and source records attributed to R Salvador.

At least 19 recordsLinked to original sources

Minimally invasive enucleation of esophageal leiomyoma.

BACKGROUND: Leiomyoma accounts for 70% of all benign tumors of the esophagus. Open enucleation via thoracotomy has long been the standard procedure, but thoracoscopic and laparoscopic approaches have recently emerged as interesting alternatives. To date, only case reports or very small series of such techniques have been reported. The authors report their experience over the past decade. METHODS: Between January 1999 and August 2005, 11 patients (6 men and 5 women; median age, 44 years) underwent surgery after presenting with dysphagia, chest pain, or heartburn. The surgical approaches included right video-assisted thoracoscopy (n = 7) for tumors of the middle lower third of the esophagus and laparoscopy (n = 4) for tumors within 4 to 5 cm of the lower esophageal sphincter or located at the gastroesophageal junction (GEJ). Intraoperative endoscopy with air insufflation during enucleation was used to confirm mucosal integrity and safeguard against esophageal perforation. Reapproximation of the muscle layers was performed after tumor enucleation to prevent the development of a pseudodiverticulum. A Nissen or Toupet fundoplication was added for patients undergoing laparoscopic enucleation of the leiomyoma. RESULTS: The median operative time was 150 min. All tumors were benign leiomyomas (median size, 4.5 cm). One leiomyoma located at the gastroesophageal junction required intraoperative mucosal repair with three stitches for an esophageal perforation (preoperative biopsies had been taken). There were no major morbidities, including deaths or postoperative leaks. The median postoperative hospital stay was 6 days. All the patients were free of dysphagia during a median followup period of 27 months. One patient had a small (< 2 cm) asymptomatic pseudodiverticulum at the 6-month follow-up endoscopy. CONCLUSIONS: Video-assisted enucleation of esophageal leiomyoma can be performed effectively and safely with no mortality and low morbidity. Thoracoscopic and laparoscopic techniques for the removal of esophageal leiomyomas may be recommended as the treatment of choice in centers experienced with minimally invasive surgery.

Adult↗

Influence of improved teaching on medical students' acquisition and retention of drug administration skills.

BACKGROUND: Drug administration error is a major problem causing substantial morbidity and mortality worldwide. Lack of education about drug administration appears to be a causative factor. We devised an online teaching module for medical students and assessed its short- and long-term efficacy. METHODS: One hundred and thirty clinical medical students were invited to undertake additional, online, teaching about drug administration. Those participating were identified and the number of web pages viewed recorded. The students' knowledge retention was tested by means of drug administration questions incorporated into routine assessments and examinations over the next 6 months. Other indices of all students' performance were recorded to correct for confounding factors. RESULTS: Just over half (52%) responded to the invitation to participate. The amount of interest they showed in the teaching module correlated positively with their performance in questions about drug administration, although the latter waned over time. Surprisingly, correcting for students' general ability and keenness revealed that the less able students were most likely to undertake the teaching module. CONCLUSIONS: Additional online teaching about drug administration improves students' knowledge of the topic but clearly requires reinforcement; however, only about half the students took up the option. Medical students must acquire these fundamental skills, and online teaching can help. Medical educators must ensure that drug administration is taught formally to all students as part of the curriculum and must understand that it may require additional teaching.

Chemistry, Pharmaceutical↗

Physiological thresholds for irreversible tissue damage in contusional regions following traumatic brain injury.

Cerebral ischaemia appears to be an important mechanism of secondary neuronal injury in traumatic brain injury (TBI) and is an important predictor of outcome. To date, the thresholds of cerebral blood flow (CBF) and cerebral oxygen utilization (CMRO(2)) for irreversible tissue damage used in TBI studies have been adopted from experimental and clinical ischaemic stroke studies. Identification of irreversibly damaged tissue in the acute phase following TBI could have considerable therapeutic and prognostic implications. However, it is questionable whether stroke thresholds are applicable to TBI. Therefore, the aim of this study was to determine physiological thresholds for the development of irreversible tissue damage in contusional and pericontusional regions in TBI, and to determine the ability of such thresholds to accurately differentiate irreversibly damaged tissue. This study involved 14 patients with structural abnormalities on late-stage MRI, all of whom had been studied with (15)O PET within 72 h of TBI. Lesion regions of interest (ROI) and non-lesion ROIs were constructed on late-stage MRIs and applied to co-registered PET maps of CBF, CMRO(2) and oxygen extraction fraction (OEF). From the entire population of voxels in non-lesion ROIs, we determined thresholds for the development of irreversible tissue damage as the lower limit of the 95% confidence interval for CBF, CMRO(2) and OEF. To test the ability of a physiological variable to differentiate lesion and non-lesion tissue, we constructed probability curves, demonstrating the ability of a physiological variable to predict lesion and non-lesion outcomes. The lower limits of the 95% confidence interval for CBF, CMRO(2) and OEF in non-lesion tissue were 15.0 ml/100 ml/min, 36.7 mumol/100 ml/min and 25.9% respectively. Voxels below these values were significantly more frequent in lesion tissue (all P < 0.005, Mann-Whitney U-test). However, a significant proportion of lesion voxels had values above these thresholds, so that definition of the full extent of irreversible tissue damage would not be possible based upon single physiological thresholds. We conclude that, in TBI, the threshold of CBF below which irreversible tissue damage consistently occurs differs from the classical CBF threshold for stroke (where similar methodology is used to define such thresholds). The CMRO(2) threshold is comparable to that reported in the stroke literature. At a voxel-based level, however (and in common with ischaemic stroke), the extent of irreversible tissue damage cannot be accurately predicted by early abnormalities of any single physiological variable.

Adolescent↗

Imaging of cerebral blood flow and metabolism in brain injury in the ICU.

The heterogeneity of the initial insult and subsequent pathophysiology has made both the study of human head injury and design of randomised controlled trials exceptionally difficult. The combination of multimodality bedside monitoring and functional brain imaging positron emission tomography (PET) and magnetic resonance (MR), incorporated within a Neurosciences Critical Care Unit, provides the resource required to study critically ill patients after brain injury from initial ictus through recovery from coma and rehabilitation to final outcome. Methods to define cerebral ischemia in the context of altered cerebral oxidative metabolism have been developed, traditional therapies for intracranial hypertension re-evaluated and bedside monitors cross-validated. New modelling and analytical approaches have been developed.

Animals↗

Pseudo-angiomatous stromal hyperplasia presenting as a breast mass: imaging findings in three patients.

The authors review the mammographic, ultrasonographic and magnetic resonance (MR) imaging findings in each of three patients with a breast tumor corresponding to the characteristics of pseudo-angiomatous stromal hyperplasia (PASH). Imaging findings are indistinguishable from those of the more common type of fibroadenoma, and they are categorised as BIRADS type 3 lesions (probably benign lesions). Their benign condition and behaviour compared with other similar cases, allows the recommendation that surgical excision be avoided, and the patients monitored with periodic follow-up. The diagnosis can be confidently established by sampling with a breast core biopsy in the case of any doubt about whether the lesion is benign if the patient is anxious.

Adult↗

Bilateral breast cancer associated with diffuse scleroderma.

There is a strong evidence to suggest the association between breast cancer and diffuse scleroderma, though it is an infrequent occurrence. We describe the clinical and radiological findings in a patient who, over a period of 2 years, was diagnosed initially of diffuse scleroderma, next with right breast cancer and finally with left breast cancer. A review of the literature evidencing the relation between these two pathologies is provided. We suggest that special vigilance for tumoral pathology of the breast should be performed in patients with systemic scleroderma.

Breast Neoplasms↗

Validation of a tonometric noninvasive arterial blood pressure monitor in the intensive care setting.

Intra-arterial measurement is considered the gold standard for continuous, beat-to-beat arterial blood pressure monitoring. However, arterial cannulation can be difficult and may cause complications such as thrombosis and ischaemia. Recently, a tonometric system, the Colin CBM-7000 has been developed for noninvasive beat-to-beat measurement of arterial blood pressure from the radial artery. We assessed the level of agreement between the CBM-7000 and invasive radial artery measurements in 15 patients on a neuro-intensive care unit. Agreement of systolic, diastolic and mean arterial pressure values was limited, with approximately 34% of mean arterial pressures differing by over 10 mmHg. In many cases, this was due to a downward drift of the noninvasive measurements over time. Furthermore, there was a tendency to underestimate low pressures and overestimate high pressures. In our opinion, the Colin CBM-7000 cannot be recommended for continuous blood pressure monitoring in the intensive care setting.

Adult↗

Determination of the object surface function by structured light: application to the study of spinal deformities.

The projection of structured light is a technique frequently used to determine the surface shape of an object. In this paper, a new procedure is described that efficiently resolves the correspondence between the knots of the projected grid and those obtained on the object when the projection is made. The method is based on the use of three images of the projected grid. In two of them the grid is projected over a flat surface placed, respectively, before and behind the object; both images are used for calibration. In the third image the grid is projected over the object. It is not reliant on accurate determination of the camera and projector pair relative to the grid and object. Once the method is calibrated, we can obtain the surface function by just analysing the projected grid on the object. The procedure is especially suitable for the study of objects without discontinuities or large depth gradients. It can be employed for determining, in a non-invasive way, the patient's back surface function. Symmetry differences permit a quantitative diagnosis of spinal deformities such as scoliosis.

Calibration↗

Synthesis and anti-HIV activity of new urea and nitrosourea derivatives of diamino acids.

A series of N1-methyl,N1-allyl,N1-(2-chloroethyl) and N1-propargyl urea and nitrosourea derivatives of diamino acids (L-ornithine and L-lysine) was synthesized and was shown to have weak activity in counteracting the cytopathic effects of the HIV-1 on a T4 lymphocyte cell line (CEM-IW). However, selected compounds may possess some immunomodulatory activity.

Amino Acids, Diamino↗

[An appendicular villous adenoma].

Villous adenomas of the vermiform appendix are uncommon. Their malignant potential is unknown and their treatment is controversial. Because of a reported association between adenomas of the appendix and other gastrointestinal neoplasms, long-term surveillance is recommended. A new case of appendicular villous adenoma is reported.

Adenoma↗

[Multilocular peritoneal inclusion cysts in puerperium].

We report the case of a 26 year old female with low abdominal pain occurring post-partum. Ultrasonography revealed the existence of pelvic cysts. Laparotomy allowed the resection of the cysts interpreted at that time as hydatic cysts. Four months later the patient was readmitted because of a recurrence of the cysts. Pathological examination made the final diagnosis of multilocular peritoneal inclusion cysts. The literature on this rare condition, previously denominated cystic benign mesothelioma, is reviewed. Recurrence may be prevented by the use of sclerosing agents during the surgical intervention.

Adult↗

Effects of maxillary protraction determined by laser metrology.

In this work we studied some of the main effects of the maxillary protraction orthopedic device. The initial dento-craniofacial reactions induced by maxillary protraction similar to that commonly employed in clinical practice are reported. The fringe counting holographic interferometry technique is used to measure displacements. The experiments were performed on a dried human skull; traction application points were situated over the permanent lateral incisors or over the first permanent molars. The results fundamentally reveal an anterior rotation of the dentomaxillary complex, more intense when traction is applied to the lateral incisors, as shown by a more marked extrusion of the molars in this case. Moreover, major deformation patterns could be observed in inner hard structures of the skull base when applying orthopaedic forces.

Child↗

[Surface gastric cancer. Lymphatic metastases].

We present 10 cases of early gastric carcinoma with lymph node invasion in a series of 40 cases early gastric cancer operated between 1974 and 1984 in our unit. Two tumours were mucosal and 8 were submucosal. One tumour was polypoid, 5 were superficiel and 4 were ulcerated. The mean number of invaded lymph nodes was 2.7. We performed a total gastrectomy in two patients and a distal gastrectomy in the other eight patients. Two patients died 26 and 27 months after the operation. The others are alive and tumour free. We believe that early gastric cancer must be treated aggressively by means of total or partial gastrectomy with resection of the N1 and N2 lymph node chains, when ever possible.

Adult↗