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Biomedical subjects

A Aharon

Publications and source records attributed to A Aharon.

At least 19 recordsLinked to original sources
PubMed2000

The paracetamol absorption test: a useful addition to the enteral nutrition algorithm?

BACKGROUND: Enteral nutrition in critically ill patients given via the nasogastric route is often decreased or stopped because of large gastric residual volumes. AIM: To assess the effect of continuing enteral nutrition in patients with an elevated gastric residual volume but normal gastric emptying by the paracetamol absorption test. METHODS: The paracetamol absorption test was performed on all patients receiving enteral nutrition via a nasogastric tube who had a residual volume (assessed every 8 hours) of >150 ml or more than twice the hourly infusion rate. Patients were then divided into 2 groups according to the result of the test: Group 1 (n=8), normal gastric emptying; and Group II (n=24), abnormal gastric emptying. Group I continued to receive enteral nutrition. In Group II feeding was interrupted in 18 patients and prokinetic agents administered, while a subgroup of six patients continued to receive enteral nutrition without prokinetic agents. All patients were followed for evidence of delayed gastric emptying and aspiration. RESULTS: Residual volumes were similarly elevated in both groups (p=0.25). Enteral nutrition was continued in Group I with no adverse effects. Prokinetic agents allowed enteral nutrition to be resumed in 88% of the 18 Group II patients. Enteral nutrition in the subgroup had to be stopped because of persistently elevated residual volumes. CONCLUSION: The paracetamol absorption test may be normal in patients with relatively high gastric residual volumes. These patients may continue to receive enteral nutrition.

Acetaminophen↗
PubMed1997

Successful treatment of early secondary myelofibrosis in SLE with IVIG.

Myelofibrosis has been reported as a rare cause of pancytopenia in patients with autoimmune diseases. We describe a 54y old female patient who was admitted with severe anemia subsequently found to be due to marrow fibrosis. During the course of her hospitalization, relying both on her clinical symptoms as well as the results of a wide range of laboratory tests and diagnostic procedures, the diagnosis of systemic lupus erythematosus was established. The patient was treated with high dose steroids, but improvement of her clinical symptoms as well as normalization of her peripheral blood count were achieved only after high dose intravenous therapy with gamma globulin (IVIG) was instituted. Along with the improvement in the peripheral blood parameters normalization of the bone marrow architecture was recorded on a repeated bone marrow biopsy. IVIG therapy should be considered in extreme cases of bone marrow suppression in SLE.

Biopsy↗
PubMed1995

Modification of the Fontan procedure. Superior vena cava to left pulmonary artery connection and inferior vena cava to right pulmonary artery connection with adjustable atrial septal defect.

BACKGROUND: A modification of the Fontan procedure with unidirectional cavopulmonary connection is described in which the superior vena cava (SVC) is connected to the left pulmonary artery (PA) and the inferior vena cava (IVC) is connected to the right PA via a lateral tunnel with a snare-controlled, adjustable atrial septal defect (ASD). This allows matching of the SVC and IVC flows with the lung of appropriate size. The obligatory left Glenn shunt provides an adequate arterial oxygen saturation, and the elevation in SVC pressure is well tolerated. The adjustable ASD allows selective decompression of the IVC that maintains cardiac output and reduces fluid accumulation in the serous cavities. METHODS AND RESULTS: Since March 1992, we have performed this procedure in 18 patients. There were 17 children and 1 adult. Median age was 3 years and 9 months (range, 13 months to 36 years). Six patients had been staged with a previous bidirectional Glenn shunt. Preoperative cardiac catheterization revealed a PA pressure of 13 +/- 2 mm Hg and a transpulmonary gradient of 5 +/- 3 mm Hg. Ventricular function was satisfactory in all patients. At the completion of bypass, the pressures in the SVC and IVC were 16 +/- 4 mm Hg and 10 +/- 3 mm Hg, respectively (P < .01). The left atrial pressure was 6.0 +/- 3.0 mm Hg and the arterial O2 saturation on 100% oxygen was 93 +/- 3%. There was one death as a result of intractable atrial arrhythmias. The remaining 17 patients had a mean hospital stay of 9.7 days (6 to 18 days). The length of pleural drainage was 7 +/- 3 days. The ASD was adjusted in 11 patients before discharge. Oxygen saturation at discharge was 85.4 +/- 4%. Nine patients had repeat catheterization. The ASD was completely closed in 6 patients, an average of 2.5 months after surgery (range, 3 weeks to 5 months). After ASD closure, the arterial oxygen saturation was 96 +/- 3%, and the SVC and IVC pressures were both 13 +/- 3 mm Hg. CONCLUSIONS: The Fontan procedure with unidirectional cavopulmonary connection and adjustable ASD has several advantages that may reduce mortality and morbidity for the high-risk Fontan candidate.

Adolescent↗
PubMed1995

The regional capillary distribution of retrograde blood cardioplegia in explanted human hearts.

Warm retrograde blood cardioplegia is frequently used for myocardial protection, despite experimental studies questioning the adequacy of capillary flow to the right ventricle and septum. The capillary distribution of retrograde blood cardioplegia in the human heart is unknown. Hearts from eight transplant recipients with the diagnosis of idiopathic or dilated cardiomyopathy were arrested in situ with cold blood cardioplegia and excised with the coronary sinus intact. Within 20 minutes of explanation, colored microspheres mixed in 37 degrees C blood cardioplegia were administered through the coronary sinus at a pressure of 30 to 40 mm Hg for 2 minutes. Twelve transmural myocardial samples were taken horizontally at the level of midventricle and apex to determine regional capillary flow rates. When retrograde warm blood cardioplegia was administered at a rate of 0.42 +/- 0.06 ml/gm/min, the left ventricle, the septum, the posterior wall of the right ventricle, and the apex consistently received capillary flow rates in excess of their metabolic requirements. The capillary perfusion of anterior and lateral walls of the right ventricle was marginally adequate to sustain aerobic metabolism. In explanted human hearts, retrograde blood cardioplegia provides adequate capillary flow to the left ventricle, the septum, the posterior wall of the right ventricle, and the apex; however, capillary flow to the anterior and lateral walls of the right ventricle is marginal. This study delineates the tenuous balance between supply and demand for right ventricular protection with warm continuous retrograde blood cardioplegia.

Capillaries↗
PubMed1995

Coronary sinus ostial occlusion during retrograde delivery of cardioplegic solution significantly improves cardioplegic distribution and efficacy.

UNLABELLED: This study documents the gross flow characteristics and capillary distribution of cardioplegic solution delivered retrogradely with the coronary sinus open versus closed. METHODS: Five explanted human hearts from transplant recipients were used as experimental models. Hearts served as their own controls and received two doses of warm blood cardioplegic solution, each containing colored microspheres. The first dose was delivered through a retroperfusion catheter with the coronary sinus open and the second dose was delivered with the sinus occluded. Capillary flow was measured at twelve ventricular sites and gross flow was measured by examining coronary sinus regurgitation, thebesian vein drainage, and aortic effluent (nutrient flow). RESULTS: Coronary sinus ostial occlusion allowed for a significant decrease in total cardioplegic flow (1.74 +/- 0.40 ml/gm versus 1.06 +/- 0.32 ml/gm; p < 0.05) to occur while maintaining an identical intracoronary sinus pressure. Ostial occlusion also resulted in an increase in the ratio of nutrient flow/total cardioplegic flow from 32.3% +/- 15.1% to 61.3% +/- 7.9% (p < 0.05). A statistically significant improvement in capillary flow was found at the midventricular level in the posterior intraventricular septum and posterolateral right ventricular free wall. This improvement was also documented for the intraventricular septum and right ventricle at the level of the apex. CONCLUSION: Coronary sinus occlusion during retrograde cardioplegia significantly improves cardioplegic delivery to the right ventricle and posterior intraventricular septum. Furthermore, the technique affords a significant improvement in nutrient cardioplegic flow while reducing the overall volume of cardioplegic solution administered.

Capillaries↗
PubMed1995

Mutual antagonistic interactions between the thyrotropin (adenosine 3',5'-monophosphate) and protein kinase C/epidermal growth factor (tyrosine kinase) pathways in cell proliferation and differentiation of cultured human thyroid follicles.

Our aim has been to delineate the role of the major signal transduction pathways believed implicated in the control of thyroid function and growth: the cAMP-, epidermal growth factor (EGF) (tyrosine kinase)-, and protein kinase C (PKC)-mediated mechanisms. The experimental model used was our system of thyroid follicles of human origin cultured in suspension under serum-free conditions in which the follicular three-dimensional structure is retained. The phorbol ester 12-O tetradecanoylphorbol 13-acetate (TPA) time and dose dependently (10(-11)-10(-7) M) inhibited TSH-stimulated thyroid functions (cAMP formation, iodide uptake and organification, and T3 secretion). TPA also inhibited such forskolin- and 8-BrcAMP-stimulated effects, suggesting that the attenuation of the cAMP-dependent pathway occurs at steps both pre- and post-cAMP formation. The effects of TPA were mimicked by another PKC activator, phorbol 12,13-dibutyrate, but not by a phorbol ester that fails to activate PKC, 4 alpha-phorbol 12,13-didecanoate, and were reversed by staurosporine, a PKC inhibitor. The TPA actions seem, therefore, to be PKC-mediated. EGF exhibited a time- and dose-dependent (0.02-8 nM) restraining influence on the above TSH-stimulated differentiated functions, except for cAMP, which was enhanced. EGF also blunted such forskolin- and 8-BrcAMP-induced response parameters, suggesting inhibition at a post-cAMP locus. Regarding cell proliferation, during the initial stages of culture (day 2), TPA dose dependently (10(-11)-10(-7) M) attenuated cell proliferation, but subsequently (day 7 of culture) the same doses of TPA stimulated cell multiplication. The TPA-mitogenic and antimitogenic effects could not be mimicked by 4 alpha-phorbol-12,13-didecanoate and were reversed by staurosporine, thus indicating a PKC-mediated pathway for such TPA actions. EGF, on the other hand, only enhanced cell proliferation at a late stage (coincident with the TPA-mitogenic effect). TSH (0.5 U/liter) inhibited both the mitogenic and antimitogenic actions of TPA as well as the cell-proliferative influence of EGF. In conclusion, the data demonstrate mutual antagonistic interactions between the signal transduction pathways: the PKC and EGF (tyrosine kinase) pathways seem to inhibit TSH (cAMP)-mediated human thyroid cell differentiation, whereas TSH attenuates PKC-mediated thyroid cell mitogenesis and antimitogenesis as well as EGF-mediated cell proliferation.

Alkaloids↗
PubMed1994

[Bacterial arthritis with E. coli in an elderly patient].

Infectious arthritis is mostly caused by hematogenous spread of Gram-positive bacteria, which often infects a previously damaged joint. During the past 20 years there has been a notable increase in joint infections caused Gram-negative bacteria. They develop mostly in patients with systemic diseases, such as malignancy, cirrhosis or HIV infection, which cause an immune deficient state. We present an 84-year old man admitted because of fever and a diagnosis of pneumonia. During hospitalization he complained of pain in his right knee. On physical examination there was evidence of local inflammation. Infection with E. coli originating in the urinary tract was diagnosed, based on synovial fluid, blood and urine cultures. He was treated with antibiotics intravenously, the knee was surgically drained, and he was discharged 4 weeks after admission. There was no underlying systemic disease in this case that could have caused an immune deficient state, which could promote the Gram-negative joint infection. The case is presented to draw attention to the possibility of infectious arthritis in an elderly patient presenting with fever. In such cases the location of the infection may not be obvious if the infected joint is deeply located parts of bones such as those of the hip, shoulder, or vertebrae. In these cases the diagnosis may be overlooked or delayed and irreversible damage to the infected joint may result.

Aged↗
PubMed1994

[Relief of recurrent pericarditis by colchicine].

The incidence of recurrence of pericarditis is about 15-32%. The most common causes include trauma, myocardial infarction, and pericardiectomy. The optimal treatment to prevent recurrence has not been fully established. Possible modalities include nonsteroid anti-inflammatory drugs, corticosteroids, azathioprine, and pericardiectomy. We describe a 19-year-old man with osteogenic sarcoma who developed recurrent pericarditis despite treatment with prednisone and pericardiocentesis. Colchicine was administered in an effort to prevent further bouts of pericarditis. During the acute phase he was treated with a combination of prednisone, 60 mg/day, and colchicine, 1 mg/day. The dose of prednisone was then lowered to 5 mg/day. There was a recurrence when he stopped taking colchicine due to abdominal discomfort. On renewal of treatment there were no further attacks during a follow-up of 16 months. We confirm the results of a previous trial which showed that colchicine may be beneficial in preventing the recurrence of pericarditis. However, these results need corroboration by a large double-blind study.

Adult↗
PubMed1994

Sjogren's syndrome in Israel: primary versus secondary disease.

Sixty Israeli patients, 30 with primary Sjögren's syndrome (SS) and 30 with rheumatoid arthritis (RA) and secondary SS, were evaluated. The Schirmer-1 test and a positive labial salivary gland biopsy were found to be the most helpful tools in assessing the diagnosis of SS. Extraglandular features such as Raynaud's phenomenon, lymphadenopathy and CNS involvement as well as parotid gland enlargement (p < 0.05) were more common in primary SS. Antinuclear antibodies, especially anti-Ro (SSA) and anti-La (SSB) were also more common in primary SS (p < 0.05). Our results are in accord with those of many European centers, despite the different genetic background.

Adult↗
PubMed1994

Autoimmune multiorgan involvement in elderly men is it SLE?

Systemic lupus erythematosus (SLE) in males and especially in the elderly is infrequent. We describe two male patients over 65 years old, who presented with anaemia, cytopenia, nephritis, and serositis, suggesting that they suffered from an autoimmune disease. Following an interval of 6 and 9 years respectively, the diagnosis of SLE was made. In both patients, hypothyroidism, and eye involvement (uveitis and iridocyclitis) were present indicating autoimmune activity or even a new autoimmune syndrome. One patient was treated with corticosteroids and azathioprine upon which he developed many side effects from the steroid therapy. The other patient received treatment with intravenous immunoglobulin (IVIG), and at a follow-up period of 18 months, the patient's condition remained stable. We suggest that in the constellation of clinically multiple organ involvement in the elderly male, the diagnosis of SLE should be considered. IVIG may be a successful alternative therapy in this subset of patients.

Aged↗
PubMed1994

Simultaneous arterial and coronary sinus cardioplegic perfusion: an experimental and clinical study.

UNLABELLED: The existence of inhomogeneous distribution of coronary flow with antegrade or retrograde perfusion alone has led to alternating between these delivery routes to maximize their individual benefits. Concern over myocardial damage prevented the simultaneous application of antegrade and retrograde cardioplegic blood delivery. Based upon the predominance of retrograde drainage via Thebesian veins, and evidence that pressure-controlled intermittent coronary sinus occlusion during antegrade cardioplegic delivery enhances its distribution and protective properties, this study tests (a) the hypothesis that simultaneous aortic and coronary sinus perfusion is safe during aortic clamping, and (b) reports initial clinical application of this combined strategy in 174 patients. Five minipigs (25-30 kg) underwent 1 hr of aortic clamping with simultaneous aortic (antegrade) and coronary sinus (retrograde) perfusion at 200 ml/min with normal blood (37 degrees C) before and after 30 minutes of perfusion with either warm (37 degrees C) or cold (4 degrees C) blood cardioplegia (BCP). Furthermore, the combined strategy was used in 174 high-risk patients (NYHA class III-IV) at 3 university hospitals to perform myocardial protection during CABG or valve replacement, or a combination of both. Included were 16 patients in cardiogenic shock and 24 undergoing reoperation. In both the clinical and the experimental studies the coronary sinus pressure was always < 40 mmHg in beating or arrested hearts. EXPERIMENTAL: Compared to control values (81.4 +/- 0.4% tissue water content), no right-ventricular (80.8 +/- 0.8%) or left-ventricular (79.5 +/- 0.3%) edema developed, no lactate was produced (control: -1.0 +/- 0.5 mg/100 g/min, empty beating: -0.64 +/- 5, and BCP arrest: -8.6 +/- 6.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

The safety of simultaneous arterial and coronary sinus perfusion: experimental background and initial clinical results.

UNLABELLED: Concern over myocardial damage from simultaneous arterial (antegrade) and coronary sinus (retrograde) perfusion has led to alternating between these delivery routes to maximize their individual benefits. Based upon predominant retrograde drainage via Thebesian veins, this study: (1) confirms experimentally the safety of simultaneous arterial and coronary sinus perfusion; and (2) reports initial clinical application of this combined strategy in 155 consecutive patients. EXPERIMENTAL: Five mini-pigs (25 to 30 kg) underwent 1 hour of aortic clamping with simultaneous aortic and coronary sinus perfusion at 200 mL/min with normal blood (37 degrees C) before and after 30 minutes of perfusion with either warm (37 degrees C) or cold (4 degrees C) blood cardioplegia. Coronary sinus pressure was always less than 30 mmHg. There was no right or left ventricular edema, lactate production, or lipid peroxidation as transmyocardial and myocardial conjugated dienes were unaltered, and postbypass recovered left ventricular end-systolic elastance (conductance catheter) and preload recruitable stroke work index 101% +/- 3% and 109% +/- 90%, respectively. CLINICAL: Simultaneous arterial/coronary sinus perfusion was used in 155 consecutive high risk patients (New York Heart Association Class III to IV) undergoing isolated coronary artery bypass grafting (CABG) (n = 109) and CABG+valve replacement/repair or aneurysm (n = 46). Included were 16 patients in cardiogenic shock and 24 undergoing reoperation. Mean aortic clamping time averaged 90 +/- 4 minutes (range 30 to 207), with 3.5 +/- 0.1 grafts per patient; all anastomoses were performed with the aorta clamped. Cold intermittent blood cardioplegia was used for distal anastomoses and valve implantation/repair in 123 patients, and warm continuous blood cardioplegia was used in 32 patients. Following a warm cardioplegic reperfusate, all patients received warm noncardioplegic blood perfusion simultaneously via grafts and coronary sinus. Coronary sinus pressure was always less than 40 mmHg. Of 18 patients requiring postoperative mechanical circulatory support (IABP), 16 had IABP placed preoperatively for cardiogenic shock. There were three postoperative myocardial infarctions (2%), and six patients died (3.9% mortality). CONCLUSION: These experimental and clinical findings overcome perceived concerns about myocardial damage from simultaneous arterial and coronary sinus perfusion, and suggest this approach may add to the armamentarium of cardioprotective strategies.

Anastomosis, Surgical↗
PubMed1994

Surgical management of pulmonary atresia with ventricular septal defect and multiple aortopulmonary collaterals.

Pulmonary atresia with ventricular septal defect and multiple aortopulmonary collaterals is a form of complex congenital heart disease that is the subject of continued controversy. Disagreement exists regarding the appropriateness of surgical therapy, the timing of operation, and the optimal techniques for repair (1,2). The reason for these differences centers around the diversity of morphologic and consequent physiologic forms with which this defect presents. The relatively small number of patients and large number of subgroups make meaningful comparison between differing treatment strategies difficult. We present here the approach to these patients that is currently employed at UCLA Medical Center.

Abnormalities, Multiple↗