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Biomedical subjects

A Saenz

Publications and source records attributed to A Saenz.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Extraperitoneal laparoscopic adrenalectomy].

Laparoscopic adrenalectomy has recently been shown to be safe and effective for a variety of benign adrenal tumors, such as aldosterone adenoma, pheochromocytoma, nonfunctioning adenoma, Cushing's adenoma and Cushing's syndrome. Recently, laparoscopic surgeons adopted an extraperitoneal approach in which a space is created by the introduction of a trocar with an inflatable balloon tip. This technique with a minimal access procedure provides direct access to the adrenal glands without interfering with intraperitoneal organs. Laparoscopic adrenalectomy using the extraperitoneal approach was completed in 18/20 consecutive patients. Mean operative time was 95 min (range 80-120) and median hospital stay 3 days. Blood transfusion was not required, and there were no postoperative complications.

Adenoma↗
PubMed1999

The effectiveness of glucocorticoids in treating croup: meta-analysis.

OBJECTIVE: To determine the effectiveness of glucocorticoid treatment in children with croup. DESIGN: Meta-analysis of randomised controlled trials that examine the effectiveness of glucocorticoid treatment in children with croup. MAIN OUTCOME MEASURES: Score on scale measuring severity of croup, use of cointerventions (adrenaline (epinephrine), antibiotics, or supplemental glucocorticoids), length of stay in accident and emergency or in hospital, and rate of hospitalisation. RESULTS: Twenty four studies met the inclusion criteria. Glucocorticoid treatment was associated with an improvement in the croup severity score at 6 hours with an effect size of -1.0 (95% confidence interval -1.5 to -0.6) and at 12 hours -1.0 (-1.6 to -0.4); at 24 hours this improvement was no longer significant (-1.0, -2.0 to 0.1). There was a decrease in the number of adrenaline treatments needed in children treated with glucocorticoids: a decrease of 9% (95% confidence interval 2% to 16%) among those treated with budesonide and of 12% (4% to 20%) among those treated with dexamethasone. There was also a decrease in the length of time spent in accident and emergency (-11 hours, 95% confidence interval -18 to 4 hours), and for inpatients hospital stay was reduced by 16 hours (-31 to 1 hour). Publication bias seems to play a part in these results. CONCLUSIONS: Dexamethasone and budesonide are effective in relieving the symptoms of croup as early as 6 hours after treatment. Fewer cointerventions are used and the length of time spent in hospital is decreased in patients treated with glucocorticoids.

Anti-Bacterial Agents↗
PubMed1999

Retroperitoneal approach in laparoscopic adrenalectomy: is it advantageous?

Recently, the retroperitoneal laparoscopic approach has been described as advantageous in avoiding the respiratory and hemodynamic effects of CO2 pneumoperitoneum and giving direct access without the need to move abdominal organs. Forty-two laparoscopic adrenalectomies (LpA) were performed in 36 patients with a variety of adrenal disorders, including 9 patients with nonfunctioning tumors, 11 patients with aldosterone adenoma, 10 patients with Cushing's adenoma, and 6 patients with Cushing's disease. Twenty-two adrenalectomies were performed using the transperitoneal approach (TLpA), and 20 via the retroperitoneoscopic approach (RLpA). Arterial blood samples, mean arterial pressure, heart rate, and clinical parameters were evaluated. At the end of the operation, the PaCO2, PetCO2, and base deficit all increased significantly in both retroperitoneal and transperitoneal CO2 insufflation compared with basal values. Arterial pH decreased significantly in both TLpA and RLpA groups. All clinical parameters evaluated (operation time, analgesic dosing requirements, hospital stay, and the days until return to normal activity) were similar in the TLpA and RLpA approaches. Two patients in the TLpA (10.5%) group and two patients in the RLpA (10%) group needed conversion to open surgery. This study shows the safety and efficacy of laparoscopic adrenalectomy via the transperitoneal or retroperitoneal route in patients with a variety of adrenal disorders. The retroperitoneoscopic approach could be the primary choice in patients with previous abdominal surgery.

Adolescent↗
PubMed1999

Calpainopathy-a survey of mutations and polymorphisms.

Limb-girdle muscular dystrophy type 2A (LGMD2A) is an autosomal recessive disorder characterized mainly by symmetrical and selective atrophy of the proximal limb muscles. It derives from defects in the human CAPN3 gene, which encodes the skeletal muscle-specific member of the calpain family. This report represents a compilation of the mutations and variants identified so far in this gene. To date, 97 distinct pathogenic calpain 3 mutations have been identified (4 nonsense mutations, 32 deletions/insertions, 8 splice-site mutations, and 53 missense mutations), 56 of which have not been described previously, together with 12 polymorphisms and 5 nonclassified variants. The mutations are distributed along the entire length of the CAPN3 gene. Thus far, most mutations identified represent private variants, although particular mutations have been found more frequently. Knowledge of the mutation spectrum occurring in the CAPN3 gene may contribute significantly to structure/function and pathogenesis studies. It may also help in the design of efficient mutation-screening strategies for calpainopathies.

Amino Acid Sequence↗
PubMed1998

Interactive image-guided surgical resection of intracranial arteriovenous malformations.

Surgical excision is the only treatment method that immediately prevents increased morbidity or mortality as a result of hemorrhage from arteriovenous malformations (AVMs). For those lesions located deep within the cerebral hemispheres or near eloquent areas, conventional surgical resection may be associated with an unacceptable degree of morbidity and mortality. Herein we report our experience in the resection of these lesions using interactive image guidance. There were five women and five men in the patient group. Their age ranged from 16 to 73 years (mean = 41). Clinical presentation included hemorrhage (n = 7), headaches (n = 2), and seizures (n = 1). All lesions were classified using the Spetzler-Martin grading system as follows: grade I (n = 4), grade II (n = 5), and grade III (n = 1). The locations of the lesions were supratentorial (9) and infratentorial (1). Surgical planning was carried out using the Neurological Surgery Planning System software developed at Wayne State University. An infrared-based system was used to locate and define the lesion intraoperatively. For those lesions located near or within eloquent areas, an awake craniotomy with functional mapping was carried out. Clinical follow-up ranged from 3 to 62 months (mean = 34). Complete surgical excision was achieved in all patients, which was demonstrated postoperatively by digital substraction angiography. The preoperative neurological status remained unchanged in seven patients and improved in three. There was no associated morbidity and mortality with this technique. Image-guided surgical resection of arteriovenous malformations represents a valuable technique, especially in small deep-seated lesions and in those near eloquent areas.

Adolescent↗
PubMed1998

Interactive image guided surgery of the pineal region.

A wide variety of lesions occur in the pineal region. Of these, only 25% may benefit from surgical resection, being benign or radioresistant in nature. In the remaining 75% (malignant or radiosensitive), a conservative approach is preferred. Surgical resection of lesions arising from the pineal region has been associated with high morbidity and mortality, due to the complex microanatomy of this area. Recently computer-assisted surgery has emerged as an ideal method to safely approach many intracranial lesions. In the present study we discuss our experience in interactive image-guided surgical management of pineal mass lesions, in terms of patient selection, methodology, and surgical morbidity and mortality. From July 1992 to December 1996, 15 patients underwent interactive image guided surgical procedures. There were eight men and seven women. Age ranged from 5 to 79 years (mean 30). Preoperatively all patients underwent neuroimaging studies that included computed tomography and magnetic resonance imaging under stereotactic conditions. Surgical planning was carried out using the Neurological Surgical Planning System software developed at Wayne State University. In patients with a preoperative diagnosis of a malignant or radiosensitive lesion (n = 10), an interactive image-guided stereotactic biopsy was considered, whereas for those with benign or radioresistant lesions (n = 5) surgical excision using an infrared based system was carried out. Histological diagnosis was obtained in all patients. There was no morbidity and mortality associated with computer-assisted procedures for biopsies the diagnostic yield was 100%. For patients that underwent interactive image-guided surgery, gross total removal was accomplished in 3 and in 1 patient a subtotal resection greater than 90% was achieved. Interactive image-guided biopsy represents a safe and accurate method in the diagnosis of malignant and/or radiosensitive pineal lesions. Using this technique surgeons can simulate preoperatively the surgical trajectory, thus avoiding damage to critical and vascular structures. For patients with benign or radioresistant lesions, computer-assisted surgical excision is recommended.

Adolescent↗
PubMed1997

Interactive image-guided resection of cerebral cavernous malformations.

Between July 1992, and February 1997, 15 patients with cavernous malformations underwent interactive image-guided resection of their lesions. There were eight women and seven men in the group, ranging in age from 6 years to 62 years (mean 34 years). Clinical presentations included seizures (n = 7), headache (n = 4), and hemorrhage (n = 4). Prior conventional subtotal resection had been performed in one patient, and a history of prior hemorrhage was found for two patients. Diagnosis was made using magnetic resonance imaging and digital substraction angiography. Locations of the lesions were temporal (n = 9), frontal (n = 3), thalamus (n = 1), basal ganglia (n = 1), and pons (n = 1). Size ranged from 9 to 20 mm (mean 12 mm). For those lesions located near or within eloquent areas (n = 7), an awake craniotomy with functional cortical and subcortical mapping was performed. An infrared system was used intraoperatively to confirm the location and the extent of the resection of these lesions in real time. In 1996 we started using a robotic microscope to aid in localization and resection. Clinical follow-up ranged from 2 to 54 months (mean 27 months). In all 15 patients, complete surgical resection was achieved as demonstrated by postoperative magnetic resonance imaging studies. Two patients had postoperative transient neurological deficits (13.3%) that cleared over a 6-month period. One of them had a lesion in the pons, with multiple cranial nerve deficits postoperatively that gradually improved. There was no associated mortality. Histological diagnosis was consistent with cavernous angioma in all cases. Clinical follow-up revealed that 13 patients experienced complete recovery from preoperative symptoms and two patients with seizures showed marked improvement. We conclude that interactive image-guided surgery for deep-seated cavernous malformations represents a very accurate and safe approach.

Adolescent↗
PubMed1997

Radiosurgical treatment of meningiomas.

From January 1992 to November 1996, 17 patients with the diagnosis of intracranial meningioma underwent radiosurgical treatment. Of these, 7 patients were treated using a Linac-based system (group 1), and 10 using the Leksell Gamma Knife unit (group 2). The follow-up ranged between 12 and 48 (median 33) months for group 1 and between 1 and 11 (median 5) months for group 2, consisting of clinical and MRI assessments every 3 months during the first year, and every 6 months thereafter. There were 14 women and 3 men. The mean age was 42 years. Prior to radiosurgery, 15 patients underwent surgical procedures. Histological diagnosis was consistent with benign meningioma, except in 2 patients (malignant meningioma). In 15 patients with benign meningiomas there was no evidence of tumor growth as demonstrated by clinical and radiological evaluation, in 2 patients with a malignant histological type there was tumor progression.

Adult↗
PubMed1996

Early hearing testing of still critically ill neonates.

OBJECTIVE: To use a newly applied hearing screening technique for early measurement in neonatal intensive care unit (NICU) patients to learn more about the high incidence of hearing loss in this population. METHODS: An automated, portable infant hearing screener that measures the auditory brain-stem response at the bedside was used at the NICU of the Hospital Nacional de Niños, San Jose, Costa Rica. Patients were evaluated early, even if they were on a ventilator. The screener tested with a 40-dB hearing level click stimulus to each ear over a bandwidth of 750 to 3000 Hz. RESULTS: During a 15-month period, 92 newborns underwent 226 auditory brain-stem response tests (range, one to six tests; mean, 2 1/2 tests). Before discharge from the NICU or death, each infant was successfully screened. Of 72 infants discharged from the hospital alive, 68 passed bilaterally and four failed bilaterally, a 6% failure rate. Of 20 infants who died, 15 failed bilaterally, a 75% failure rate. Persistent bilateral failure of the test was detectable from each infant's first test and showed an association (chi-square, P<.001) with death. The overall bilateral failure rate was 21%. CONCLUSIONS: Simple bedside auditory brain-stem response screening of all NICU infants was consistently possible regardless of clinical status, the early onset of hearing loss suggests that NICU treatment was not ototoxic and the unexpectedly high overall bilateral test failure rate resulted from the inclusion of patients who would have died untested if conventional testing had been done.

Audiometry, Evoked Response↗
PubMed1996

Follow-up study of the revascularization process of cryopreserved islets of Langerhans.

Cryopreservation of islets of Langerhans is a necessary procedure since human pancreatic islet transplantation has become a reality for the clinical treatment of Type I, insulin-dependent diabetes mellitus. Although successful cryopreservation of rodent and human islets is a well-established technique for islet storage after isolation and purification, little is known about the influence of the freeze-thaw procedure on the islets' potential to induce angiogenesis and revascularization, a major process necessary for the viability of grafted cells. In this study, the revascularization process of cryopreserved islets transplanted in the liver and in the renal subcapsular space of diabetic and nondiabetic rats is analyzed by a double indirect immunofluorescence technique. Frozen-thawed pancreatic islets were cooled slowly to -40 degrees C, stored at -196 degrees C, and thawed rapidly. Lewis rat were grafted with either Lewis (isografts) or Wistar (allografts) overnight-cultured and frozen-thawed islets obtained by collagenase digestion. Rats were killed different days after implantation, and the livers and kidneys bearing the grafted islets were snap-frozen and immunohistochemically stained with a double immunofluorescence technique using a rabbit anti-factor VIII antiserum (which labels endothelial cells) and a guinea pig anti-insulin antibody. Overnight-cultured islet grafts completed revascularization by Days 4-7 after transplantation, as shown by the detection of endothelial cells within and surrounding the islets. The identical staining pattern of revascularization was observed in islets frozen-thawed before transplantation. It is concluded that islet cryopreservation is a suitable technique for long-term storage prior to transplantation since it does not interfere with the neovascularization process of islet grafts.

Animals↗
PubMed1996

Laparoscopic unilateral and bilateral adrenalectomy for Cushing's syndrome. Transperitoneal and retroperitoneal approaches.

OBJECTIVE: This prospective randomized study compares the safety and efficacy of transperitoneal laparoscopic adrenalectomy (TLPA) and retroperitoneal approach (RLPA) in obese patients with Cushing's syndrome. SUMMARY BACKGROUND DATA: Recently, a retroperitoneal laparoscopic approach has been described with benefits of avoiding the respiratory and hemodynamic effects of carbon dioxide (CO2) pneumoperitoneum and giving direct access without the need to mobilize abdominal organs. METHODS: Twenty-one adrenalectomies were performed in 9 patients (2 men, 7 women; mean age, 46.33 +/- 19.41 years old; range, 16 to 74 years old) with Cushing's adenoma and in 6 women (mean age, 41.83 +/- 9.97 years old; range, 34 to 62 years old) with Cushing's disease. Randomization gave 10 TLPA and 11 RLPA. Arterial blood gas samples, mean arterial pressure, heart rate, and clinical parameters were evaluated. RESULTS: The partial pressure of carbon dioxide (PaCO2) increased in both retroperitoneal and transperitoneal CO2 insufflation compared with basal values (p < 0.01), and the TLPA showed a greater rise in the PaCO2 level compared with the RLPA at 30 minutes (p < 0.05); simultaneously, a significant increase (p < 0.05) of mean arterial pressure was observed in the TLPA compared with RLPA. No significant changes in heart rate were observed in both groups. The operative time with the TLPA and RLPA in patients with adenoma was 88.75 versus 105 minutes, respectively (p = not significant [NS]), and in patients with bilateral hyperplasia was 271.66 versus 305 minutes, respectively (p = NS). No patients required blood transfusions. The number of doses of analgesic with TLPA and RLPA in patients with adenoma was 3.25 versus 3.5, respectively (p = NS), and in patients with bilateral hyperplasia was 7.66 versus 7.33, respectively (p = NS). The hospital stay with TLPA and RLPA in patients with adenoma was 3.0 versus 2.75 days, respectively (p = NS), and in patients with bilateral hyperplasia was 6.0 versus 6.66 days, respectively (p = NS). The days to return to normal activity with TLPA and RLPA in patients with adenoma were 12.5 versus 12.25, respectively (p = NS), and in patients with bilateral hyperplasia were 19.66 versus 19.33, respectively (p = NS). Two patients with bilateral hyperplasia and TLPA had urinary infection. CONCLUSIONS: Transperitoneal laparoscopic adrenalectomy and RLPA may become the techniques of choice for surgical removal of the adrenal lesions in Cushing's syndrome. The retroperitoneoscopic approach might be a better option in patients with previous abdominal surgery and in patients with pre-existing cardiorespiratory disease.

Adenoma↗
PubMed1996

Brain SPECT with dipyridamole stress to evaluate cerebral blood flow reserve in carotid artery disease.

UNLABELLED: This is a preliminary study of SPECT brain scan using dipyridamole as a stress agent to assess cerebral blood flow reserve in six patients with severe carotid artery disease. METHODS: We performed SPECT scanning of the brain, with and without dipyridamole stress. Dipyridamole (0.57 mg/kg) was given intravenously 3 min before infusion of 99mTc-HMPAO. Patients were studied 30 min later using a rotating head gamma camera. The scans were analyzed qualitatively and semiquantitatively. An acetazolamide stress SPECT image was also obtained in two patients. RESULTS: All patients had at least 80% stenosis in one internal carotid artery, three of them also had contralateral carotid stenosis. The dipyridamole SPECT showed an increased region of hypoperfusion in the hemisphere ipsilateral to the severe carotid disease in four patients. That suggests poor perfusion reserve and the potential risk of regional ischemia. In four of six patients, side-to-side asymmetry increased from the baseline condition after injection of dipyridamole. The asymmetry index increased more after dipyridamole than after acetazolamide injection in two patients. CONCLUSION: This study suggests that dipyridamole stress SPECT is useful in assessing cerebral blood flow reserve. It demonstrates the region of poor vascular reserve in patients with severe carotid artery disease. Dipyridamole SPECT scans show more extensive hypoperfusion than acetazolamide in the two cases.

Acetazolamide↗
PubMed1995

Operative enteroscopy. A useful tool in the evaluation and intervention of bilioenteric anastomoses.

Roux-en-Y hepaticojejunostomy is the procedure of choice in the management of patients with major bile duct injuries. In instances of anastomotic stricture, this anastomosis is inaccessible to conventional endoscopy. A technique is described for assessment and intervention of bilioenteric anastomoses that escape the reach of conventional endoscopy. Three cases are presented illustrating the feasibility of open and laparoscopic-assisted small-bowel endoscopy. All patients presented with recurrent cholangitis and had multiple interventions in their biliary tree prior to referral. At operation, the limb of jejunum going to the bilioenteric anastomosis was identified, an enterotomy was made, and a flexible endoscope was passed to evaluate the anastomosis. In two cases the anastomosis was revised by endoscopically excising scar tissue. In the third case the anastomosis was patent and unnecessary intervention was avoided. There was no morbidity or mortality and the patients had complete resolution of their symptoms. Operative endoscopy appears to be useful in the evaluation and intervention of bilioenteric anastomoses that cannot be evaluated by conventional endoscopy.

Adult↗
PubMed1994

Immunocytochemical study of pancreatic islet revascularization in islet isograft. Effect of hyperglycemia of the recipient and of in vitro culture of islets.

We studied the revascularization process of isogeneic islets grafted into the kidney subcapsular space of streptozotocin-induced diabetic and nondiabetic rats by a double-labeling, indirect immunofluorescence technique using a rabbit antiserum to human factor VIII-related antigen (which identifies endothelial cells) and a guinea pig anti-insulin antiserum (which labels pancreatic beta cells). Freshly isolated islets contained a network of capillary endothelial cells, whereas 1-week-cultured islets at 37 degrees C have completely lost their intra-islet endothelial cells. Overnight cultured islets contained only occasional endothelial cells. When these islets were grafted under the kidney capsule of nondiabetic rats, they rapidly acquired a new endothelial cell lining as demonstrated by the positivity of staining for factor VIII-related antigen at day 5 after implantation. On the other hand, 1-week-cultured islets failed to become fully revascularized until day 7 after transplantation. Streptozotocin-induced diabetic rats grafted with 1000 islets normalized their blood glucose values (< 11 mM/L) 2-4 weeks after implantation, whereas transplantation of 2500-3000 islets resulted in normoglycemia after 4.7 +/- 2 days (mean +/- SD). Nevertheless, hyperglycemia of the recipient did not adversely affect the process of revascularization of islet isografts which initiated at day 3 and was almost completed by day 5 after implantation.

Animals↗
PubMed1994

Pharmacodynamic activity of intravenous E-3174, an angiotensin II antagonist, in patients with essential hypertension.

Losartan potassium (DuP 753), an orally active angiotensin II receptor antagonist, is metabolized to a more potent active metabolite, E-3174, which contributes to losartan's long duration of action. The acute pharmacodynamic actions of intravenous (i.v.) E-3174 (20 mg infused over 4 h) were compared to placebo (vehicle) in two groups of patients with essential hypertension. Patients with supine diastolic blood pressure (SuDBP) of 100 to 120 mm Hg entered a 2-day inpatient phase and received vehicle on day 1. Patients with SuDBP > or = 95 mm Hg were randomized to double-blind treatment the next day. E-3174 significantly (P < .05) reduced SuDBP compared to placebo, beginning at approximately 100 min after the start of the infusion, with a maximum hypotensive effect at 8 h. Supine systolic blood pressure was also reduced by E-3174. Supine and standing heart rates did not differ between treatments. Mean E-3174 plasma levels were 324.6 ng/mL at 20 min and approximately 1000 ng/mL at the end of the 4-h infusion; during this time there was a modest decrease in blood pressure. Following the infusion, the relationship between plasma E-3174 levels and SuDBP was confounded by much larger decreases in blood pressure, which occurred as plasma drug concentrations declined. Urinary excretions of sodium, potassium, or chloride were not significantly altered by E-3174 nor was the fractional excretion of uric acid significantly different between groups. There were no drug-related or serious adverse experiences and no patient discontinued treatment due to an adverse experience.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗