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Biomedical subjects

T Horne

Publications and source records attributed to T Horne.

At least 19 recordsLinked to original sources
PubMed2004

The effect of sildenafil on gastric emptying in patients with end-stage renal failure and symptoms of gastroparesis.

BACKGROUND: Delayed gastric emptying is a common disorder among patients with end-stage renal failure (ESRF). Pyloric relaxation, a major determinant of gastric emptying, is a nitric oxide (NO)-mediated process. NO-induced smooth muscle relaxation is mediated through its second messenger cyclic guanosine monophosphate, which is broken by tissue phosphodiesterases (PDEs). Thus the inhibition of cyclic guanosine monophosphate breakdown by PDE inhibitors can potentiate NO-mediated responses and facilitate pyloric relaxation. In an animal model of diabetes mellitus, treatment with sildenafil (a PDE-5 inhibitor) restored NO-mediated pyloric relaxation and improved gastric emptying. The aim of our study was to examine the hypothesis that sildenafil may improve gastric emptying in patients with ESRF and symptoms of gastric paresis. METHODS: We studied 12 patients with ESRF (6 men; age range, 54-80 years; 5 with diabetic nephropathy; 4 +/- 1 years receiving long-term renal replacement therapy) after either placebo or a 25-mg tablet of sildenafil (Viagra; Pfizer Inc). Gastric emptying of a solid meal (one medium-sized fried egg mixed with 37 MBq [1 mCi] technetium Tc 99m phytate plus 1 slice of bread and 150 mL of water at the end of the meal) was assessed 1 hour after dosing by use of a single-headed camera. Images were acquired every 30 seconds for 90 minutes immediately after patients ate. RESULTS: The gastric emptying rate was decreased at baseline (after placebo), to 33% +/- 6% (normal, > or =50%). Treatment with sildenafil had no effect on gastric emptying rates after 90 minutes (from 33% +/- 6% after placebo to 30% +/- 6% after sildenafil, P =.9). CONCLUSIONS: Sildenafil did not improve gastric emptying in patients with ESRF and gastric paresis. Sildenafil may have opposing effects on gastric peristalsis (causing gastric relaxation) compared with its effects on pyloric relaxation. Studies combining sildenafil with prokinetic drugs are of interest.

Aged↗
PubMed2003

Diagnosis of normocalcemic hyperparathyroidism by oral calcium loading test.

We evaluated the oral calcium-loading test (OCLT) in diagnosing normocalcemic primary hyperparathyroidism. Calcium and PTH levels were measured before, 60, 120 and 180 min after oral 1 g of calcium gluconolactate administration in 102 consecutive females with high circulating PTH levels, and 25 controls. Patients were classified as follows: Group A, patients with a parathyroid adenoma identified by two imaging modalities. Sub-Group AO, hyperparathyroid patients [no.=13, mean age 59 yr (SD=10)] evaluated prior to parathyroidectomy. Sub-Group AH, non-operated hypercalcemic patients [no.=29, age 63 yr (SD=11)]. Sub-Group AN, normocalcemic non-operated women [no.=14, age 59 yr (SD=8)]. Group B, normocalcemic individuals [no.=46, age 58 yr (SD=11)] with negative parathyroid imaging. Group C, control patients [no.= 25, age 56 yr (SD=12)]. The concentrations of calcium and PTH overlapped in the normocalcemic groups during the OCLT. Product P, defined as circulating PTH nadir (pg/ml) x peak calcium concentration (mg/dl), better discriminated Sub-Group AN from Group B, AUC=0.98 (95% CI 0.95, 1.00) than did Ratio R, defined as relative PTH decline/relative calcium increment, AUC= 0.86 (95%CI 0.73, 0.99). Assuming normal threshold of Product P and Ratio R at 260 and 17 respectively, the combined parameters diagnose normocalcemic hyperparathyroid patients with 100% sensitivity and 87% specificity.

Adenoma↗
PubMed2001

99Tc(m)-tetrofosmin scintimammography for detecting breast cancer: a comparative study with 99Tc(m)-MIBI.

Scintimammography using 99Tc(m)-MIBI (99Tc(m)-sestamibi) has demonstrated promising results in the detection of breast cancer. Recently scintimammography using 99Tc(m)-tetrofosmin has been suggested as a better diagnostic tool and a more convenient agent to use in this condition. In this study we compared both agents in 35 consecutive women with abnormal mammographic or physical findings. Thirty-four of them underwent MIBI scan, followed by tetrofosmin scan 2 days later (performed on all 35 women). Within 2 weeks, a pathological diagnosis was obtained either by needle or open biopsy. In both scans the uptake ratio between the lesion and the background uptake was calculated. Twenty patients who underwent tetrofosmin scan and 19 patients with MIBI scan had malignant breast tumours, while 15 women had benign lesions. The sensitivity, specificity, positive and negative predictive values and total accuracy of the MIBI scan were 89.4%, 80%, 85%, 85.7% and 85.3%, respectively; almost identical values were obtained with tetrofosmin (90%, 80%, 85.6%, 85.7% and 85.7%, respectively). The uptake ratios in the MIBI and tetrofosmin scans were 1.68 +/- 0.52 and 1.7 +/- 0.47, respectively. No differences were found between the two scintimammographies in all the parameters examined. In conclusion, MIBI and tetrofosmin breast scans are accurate and equally efficient for the detection of breast malignancies.

Adult↗
PubMed2001

Thyroglossal duct cyst: is thyroid scanning necessary in the preoperative evaluation?

BACKGROUND: Evaluation of thyroglossal duct cysts before surgical excision traditionally includes hormonal evaluation, ultrasound of the neck, and thyroid scanning. OBJECTIVE: To evaluate the need for thyroid scanning in cases of thyroglossal duct cysts scheduled for operation. METHODS: A retrospective chart review of 100 cases of thyroglossal duct cyst between 1988 and 1995 was carried out. RESULTS: No cases of ectopic thyroid were detected. CONCLUSION: Our goal was to document the presence of normal thyroid tissue by non-invasive tools such as ultrasound, rather than to rule out the existence of ectopic thyroid tissue by radionuclide scanning. Radionuclide scanning is justified in cases of lingual thyroid and where a normally located thyroid gland cannot be detected.

Adolescent↗
PubMed2001

Epididymitis in childhood: a clinical retrospective study over 5 years.

BACKGROUND: Acute scrotal pain in children presents a major diagnostic and therapeutic challenge. Epididymitis has been considered uncommon in childhood. The clinical spectrum and therapeutic policy of the acute scrotum in children is continually being reassessed. OBJECTIVES: To determine whether there has been an increase in the incidence of epididymitis in children and to advocate a more selective surgical approach to the acute scrotum. METHODS: We conducted a retrospective review of 65 children admitted to our department of pediatric surgery with the diagnosis of acute scrotum during a 5 year period. RESULTS: Of the 65 children admitted with the diagnosis of acute scrotum, epididymitis was diagnosed in 42 (64.6%). The remaining cases included torsion of the testis in 12 patients (18.5%), torsion of the appendix testis in 5 (7.7%), scrotal pain and minimal physical findings in 4 (6.1%), and scrotal hematoma and idiopathic scrotal edema in one patient each. Doppler ultrasound of the groin, color Doppler ultrasound of the testis and testicular nuclide scintigraphy (Tc-99m scan) examinations were performed on 49, 30 and 57 occasions, respectively; the Tc-99m scan was the most effective tool. All the patients with epididymitis were diagnosed before surgical intervention and were treated conservatively. CONCLUSIONS: We observed an increasing frequency of epididymitis in children admitted with the diagnosis of acute scrotum.

Acute Disease↗
PubMed2001

[Epidemiological characteristics and I-131 scintigraphic of patients with papillary thyriod carcinoma with distant metastases].

One hundred and twenty-nine patients with papillary thyroid carcinoma were treated with radioiodine (I-131) and followed up in our department between the years 1992 and 2000. Thirty-three patients (25.6%) had distant metastases (mean follow-up time was 3.12 +/- 2.9 years). The incidence of distant metastases among patients with papillary carcinoma was higher in our group in comparison with most published studies. The most common sites for distant metastases were the lungs and mediastinum. In 32 of the 33 patients distant metastases were found in those sites. We characterized two main patterns of I-131 uptake in lung metastases: in the first there was diffuse lung uptake and in the second there were focal lesions. Bone metastases were only found in one patient. Distant metastases were found in 38.7% of males as compared to 21.4% of females. The age of the male patients with distant metastases was significantly higher than the age of the other patients (mean age 52.8 years, p = 0.099). There was no significant association between distant metastases and advanced age. Most cases of distant metastases in females (81%) were diagnosed at the time of the primary diagnosis as compared to less than half (42%) in males. Sixteen patients with distant metastases underwent cervical lymph node dissection. In 15 patients (94%) cervical lymph node metastases were found. It was found that 39.4% of the patients with distant metastases were born in Israel and 30.3% were born in the Soviet Union. The percentage of the patients with distant metastases, who came to Israel from the Soviet Union after the nuclear accident in Chernobyl (1986), was found to be significantly higher then their relative number in the Israeli population and higher then their relative number in the hospitalized patient population in the years of the study (24.2% as compared to 9% and 8.1% respectively). The survival rate of patients with distant metastases was 97% and for patients without metastases the rate was 100%.

Adenocarcinoma, Papillary↗
PubMed2000

[Primary breast tumor and malignant phyllodes tumor of the breast-- two rare cases demonstrated by technetium 99m scintimammography].

Breast cancer can be detected by scintimammography using Tc-99m sestamibi (MIBI). The method is highly accurate, sensitive and specific. Histologically, most of the tumors have been adenocarcinomas. We present 2 women with rare breast tumors, primary squamous cell carcinoma and malignant phyllodes tumor. In both, mammography and cytological biopsy were not diagnostic, but MIBI scintimammography demonstrated focal uptake in the diseased breast.

Breast Neoplasms↗
PubMed2000

The etiology of renal scars in infants with pyelonephritis and vesicoureteral reflux.

We aimed to investigate, by means of dimercaptosuccinic acid (DMSA) scan, the relations between vesicoureteral reflux (VUR) and its degree, pyelonephritis during infancy, and renal parenchymal findings. Seventy-four infants with pyelonephritis, 44 girls and 30 boys (mean age at their first pyelonephritic episode 4.12 months, median 3 months), were enrolled in the study. Voiding cystourethrography (VCU) and ultrasonography (US) were performed within 6 weeks following the infection. DMSA was performed at least 4 months after the urinary tract infection (UTI). The renal parenchymal pathology was defined as focal or multifocal defects or as a split renal uptake of less than 45%. DMSA scintigraphy revealed that 19% (14/74) of the children had renal damage. Renal parenchymal findings were observed only when VUR was present, and its grade was above 3/5. No abnormality was found in 51 renal units without reflux, 9 with VUR grade 1/5, and 54 with grade 2/5. Renal pathology was observed in 9/24 renal units with VUR grade 3, 3/8 with grade 4, and 2/2 with grade 5. No correlation was found between renal parenchymal defects and clinical presentation of the pyelonephritis, type of the microorganism, presence of bacteremia, or the number of recurrent infections. In adequately treated infants, renal damage is probably due to a reflux-associated, preexisting, congenital renal parenchymal pathology and not to the inflammatory process. We suggest that DMSA scintigraphy should not be performed routinely in every infant with UTI and should be reserved primarily for children with VUR grade 3 and above.

Cicatrix↗
PubMed1999

99Tcm-MIBI scintimammography for the detection of breast malignancies: the contribution of the count ratio to specificity.

We evaluated the efficacy of 99Tcm-sestamibi (MIBI) scintimammography for the detection of breast cancer in 332 patients. Two hundred and seven scans were confirmed by histological or cytological results; the other patients were examined because they belonged to high-risk groups or had dense fibroglandular breasts. Of 207 patients with histological confirmation, 112 positive studies were obtained: 86 true-positive and 26 false-positive. Scintimammography was negative in 95 patients: 88 true-negative and seven false-negative. Six of seven false-negative results were obtained in patients with impalpable tumours. The sensitivity, specificity, positive and negative predictive values were 92.5%, 77.2%, 76.8% and 92.6% respectively. The overall accuracy was 84.1%. To identify false-positive results, the count ratio of the target lesion to the contralateral normal area on 38 true-positive scans and in 26 false-positive examinations was calculated from the region of interest drawn on the 99Tcm-MIBI scan (L/N ratio). A significantly higher ratio was found for the true-positive scans (1.583 +/- 0.501 vs 1.246 +/- 0.213; P = 0.0002). In conclusion, 99Tcm-MIBI scintimammography is a sensitive and accurate method for the detection of breast malignancies.

Adolescent↗
PubMed1999

The role of morphine-augmented cholescintigraphy and real-time ultrasound in detecting gallbladder disease.

OBJECTIVE: Rapid diagnosis of acute cholecystitis is essential to minimize morbidity and mortality. The purpose of this study was to assess the diagnostic utility of cholescintigraphy using morphine augmentation compared with ultrasound, in acute and chronic gallbladder disease. METHODS: Cholescintigrams were performed on 103 patients suspected of having acute cholecystitis. In 79 patients (Group A) morphine sulfate was administered to reduce the scintigraphic imaging time if the gallbladder was not visualized during the first hour. In 24 control patients (Group B) no morphine was administered. All patients were evaluated clinically and 93 patients had concurrent ultrasound examination. RESULTS: The clinical presentation was nonspecific. The ultrasound findings were sensitive in detecting gallbladder disease (100%), but had low specificity (24%). Only findings of sediments and pericholecystic fluid were specific for cystic duct obstruction. Morphine augmentation reduced the imaging time by 126 min in patients with chronic cholecystitis. CONCLUSION: Real-time ultrasound has low specificity for gallbladder disease. In the presence of an abnormal ultrasound, it is essential to perform a hepatobiliary scan, either to exclude gallbladder disease or distinguish acute from chronic cholecystitis. Low-dose morphine administration is a safe and useful adjunct to standard cholescintigraphy by substantially reducing the time required to obtain a diagnostic study.

Acute Disease↗
PubMed1997

Solid-phase extraction of phospholipids from hemoglobin solutions using Empore styrene-divinylbenzene disks.

Styrene-divinylbenzene Empore disks were investigated for the extraction of phospholipids from red blood cells or aqueous solutions of hemoglobin as a means to reduce the time and solvent use required in sample preparation. Red blood cells are the source for hemoglobin used in the preparation of a hemoglobin-based oxygen carrier which is being developed to replace blood in transfusion therapy. Phospholipids are a major component of the membrane of red blood cells, and are toxic when administered directly into the vasculature. Sensitive analytical methods are required to detect phospholipids to ensure that concentrations in purified hemoglobin are well below toxic levels. This requires isolation from large volumes of purified hemoglobin solutions. The method described utilizes Empore disks to extract phospholipids from 30 ml of stroma free Hb preparations. Phosphatidylethanolamine, phosphatidylinositol, phosphatidylcholine and sphingomyelin were recovered with an average of 92% yield. The recovery of phosphatidylserine was 65%. The use of solvent and time required for sample preparation were reduced by an average of 80% relative to liquid-liquid extraction. The capacity of the 47-mm disk for the total of five phospholipids exceeds 0.3 mg. The method has been used for quantitation of phospholipids in red blood cells and stroma free hemoglobin solutions.

Chromatography, High Pressure Liquid↗
PubMed1996

Dumping syndrome following Nissen fundoplication, diagnosis, and treatment.

We evaluated the prevalence, diagnosis, and treatment of dumping syndrome (DS) following Nissen fundoplication in 50 consecutive infants and children who underwent the operation for gastroesophageal reflux. Examination included a preoperative dietary assessment with emphasis on specific postprandial clinical symptoms and technetium scintigraphy to evaluate gastric emptying. In the immediate postoperative period, postprandial glucose levels were examined in all patients with symptoms clinically suggestive of DS. In the late postoperative period (6 months to 5.5 years), all patients with more than one specific clinical symptom of DS were further evaluated by glucose tolerance test (GTT), HbA1C levels, and gastric technetium scintigraphy. DS was diagnosed in 15 patients (30%). Five patients had immediate severe DS (SDS), and 10 in the late postoperative course had latent postoperative DS (LDS). In all patients with DS, preoperative and postoperative gastric emptying scan T1/2 did not show any statistical significance. High levels of HbA1C ranging from 7.9 to 9% (mean, 8.25 +/- 0.5) were found in only three patients. Treatment included parenteral nutrition in one patient. All the others were successfully managed with nutritional manipulation alone, using a combination of lactose-free formula and fat emulsion. In patients whose postprandial symptoms persisted, pectin 5-15 g/day divided into six doses was added to the diet. Following 6 months of dietary treatment, the postprandial normoglycomic response was restored. Eleven patients experienced complete resolution of symptoms (78.5%), and three patients (21.4%) showed significant clinical improvement. This study indicates that DS is a common complication following Nissen fundoplication. The GTT is the most reliable examination for establishing the diagnosis. Treatment is simple and effective. The technetium gastric emptying scan and HbA1C level do not play a significant role in the diagnosis.

Adolescent↗