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Biomedical subjects

A Koren

Publications and source records attributed to A Koren.

At least 37 records · Page 2Linked to original sources
PubMed1998

Prevalence of hepatitis G virus infection in Slovenian hemodialysis patients as determined by the detection of viral genome and E2 antibodies.

The prevalence of hepatitis G virus (HGV) infection was assessed by the detection of viral genome and HGV E2 antibodies in hemodialysis patients from a dialysis unit with the highest prevalence of hepatitis C virus infection in Slovenia. HGV RNA was detected in 7 (11.9%) and HGV E2 antibodies in 20 (33.9%) of 59 hemodialysis patients. One patient had detectable HGV RNA as well as HGV E2 antibodies in her serum sample at the time of the study. The total prevalence of HGV infection was 44.1%. Our results clearly indicate that the mere detection of HGV RNA in serum samples would seriously underestimate the real prevalence of HGV infection in hemodialysis patients. Therefore, when assessing the prevalence of HGV infection in hemodialysis patients, detection of both antibody and nucleic acid is requisite.

Adult↗
PubMed1998

Association between mitral annulus calcification and carotid atherosclerotic disease.

BACKGROUND AND PURPOSE: It has been established that mitral annulus calcification (MAC) is an independent predictor of stroke, though a causative relationship was not proved, and that carotid artery atherosclerotic disease is also associated with stroke. The aim of this study was to determine whether there is an association between the presence of MAC and carotid artery atherosclerotic disease. METHODS: Of the 805 patients in whom the diagnosis of MAC was made by transthoracic echocardiography between 1995 and 1997, 133 patients (60 men and 73 women; mean age, 74.3+/-8 years; range, 47 to 89 years) underwent carotid artery duplex ultrasound for various indications; the study group comprised these patients. They were compared with 129 age- and sex-matched patients without MAC (57 men and 72 women; mean age, 73.6+/-7 years; range, 61 to 96 years) who underwent carotid artery duplex ultrasound during the same period for the same indications. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet. MAC was considered severe when the thickness of the localized, highly reflective area was > or =5 mm on 2-dimensional echocardiography in the 4-chamber view. Carotid artery stenosis was graded as follows: 0%, 20%, 40%, 60%, 80%, and 100%. RESULTS: Compared with the control group, the MAC group showed a significantly higher prevalence of carotid stenosis of > or =40% (45% versus 29%, P=0.006), which was associated with > or =2-vessel disease (23% versus 10%, P=0.006) and bilateral carotid artery atherosclerotic disease (21% versus 10%, P=0.011). Severe MAC was found in 48 patients. More significant differences were found for the severe MAC subgroup (for carotid stenosis of > or =40%) in rates of carotid artery atherosclerotic disease (58% versus 29%, P=0.001), and > or =2-vessel disease (31% versus 10%, P=0.001), in addition to bilateral carotid artery stenosis (27% versus 10%, P=0.004) and even bilateral proximal internal carotid artery stenosis (21% versus 8%, P=0.015). Furthermore, significant carotid artery atherosclerotic disease (stenosis of > or =60%) was significantly more common in the severe MAC subgroup than in the controls (42% versus 26%, P<0.05) and was associated with higher rates of > or =2-vessel disease (19% versus 7%, P=0.02) and bilateral carotid artery stenosis (17% versus 7%, P=0.05). On multivariate analysis, MAC and age but not traditional risk factors were the only independent predictors of carotid atherosclerotic disease (P=0.007 and P=0.04, respectively). CONCLUSIONS: There is a significant association between the presence of MAC and carotid artery atherosclerotic disease. MAC may be an important marker for atherosclerotic disease of the carotid arteries. This association may explain the high prevalence of stroke in patients with MAC.

Aged↗
PubMed1998

Retroperitoneal endoscopic lumbar sympathectomy with balloon dissection: experience with a cadaveric model.

The objective of this study was to determine the feasibility of retroperitoneal endoscopic lumbar sympathectomy with balloon dissection technique using a cadaveric model. Retroperitoneal endoscopic lumbar sympathectomy was performed on 10 cadavers. The procedure was combined with balloon dissection to provide easier visualization and more working space. The outcome was successful in eight cadavers. Average operating time was 40 min, and visualization was good. The only major technical problems were perforation of the peritoneum and air leak into the abdomen. It was concluded that retroperitoneal endoscopic lumbar sympathectomy with balloon dissection has the advantages of minimal invasiveness, clear visualization, and controlled blunt dissection. The use of a cadaveric model may improve the clinical learning curve.

Cadaver↗
PubMed1997

The in vivo effect of recombinant human granulocyte-colony stimulating factor in neutropenic neonates with sepsis.

The effects of recombinant granulocyte-colony stimulating factor (rhG-CSF) in neonatal neutropenia with presumed sepsis, which has a poor prognosis, were investigated. The study involved 14 neonates with presumed sepsis and neutropenia. Findings were compared with those from 24 historical controls. rhG-CSF (5 micrograms/ kg/day i.v. for 5 days) was administered immediately following diagnosis. Complete blood counts were obtained before and 24, 48, 72, 96 and 120 h after initiation of treatment. Neutrophil storage pool (NSP) was assessed (in 4 patients) before and after treatment. Statistical analysis was performed using one way analysis of variance. Treatment led to an increase in absolute neutrophil count (ANC) levels in 13/14 patients. At the end of treatment, the mean ANC was higher than that of controls (P = 0.007). There was a marked increase in the NSP of between 32% and 65% (P = 0.005). There were two clinical failures, one of whom was considered to have died from his underlying condition. There were no reports of clinical or haematological toxicity during treatment or follow up.

Analysis of Variance↗
PubMed1997

Pulmonary hypertension in patients with thalassemia major.

To evaluate the pulmonary artery pressure in patients with thalassemia major, Doppler echocardiography was performed in 33 patients with thalassemia major (aged 2 to 24 years) and 33 normal controls. Pulmonary artery pressure was estimated by (1) measuring the systolic transtricuspid gradient from tricuspid regurgitation and adding it to the right atrial pressure, estimated by the response of the inferior vena cava to deep inspiration, and (2) measuring the time to peak velocity of pulmonary flow. The results showed that of 33 patients, 28 had tricuspid regurgitation with a pulmonary systolic pressure ranging from 18 to 94 mm Hg (47 +/- 15 mm Hg). Pulmonary systolic pressure was > 30 mm Hg in all 22 patients > 10 years old and in four of six patients < 10 years old. Pressure correlated with left ventricular ejection fraction (r = -0.74), the ratio of mitral peak early diastolic flow velocity and peak velocity during the atrial contraction (r = 0.52), age (r = 0.56), and total blood transfusion units (r = 0.59). The pulmonary time to peak velocity was shortened compared with controls (p < 0.05). We concluded that pulmonary hypertension, as another cardiovascular complication of multiple factors of cause, seems to occur more frequently and at an early stage of the cardiac involvement in patients with thalassemia major.

Adolescent↗
PubMed1996

"Veno-Press"--a new sequential intermittent pneumatic device for the prevention of perioperative deep vein thrombosis.

The prevention of peri-operative deep vein thrombosis (DVT) and the potentially hazardous pulmonary embolism that may follow is still a major medical issue. Intermittent pneumatic compression is one of the many methods currently in use for this purpose. No information is available, however, regarding the venous flow alterations that occur during employment of a pneumatic compression device under general anesthesia. The aim of this study is to delineate these venous flow variations and to determine the optimal pump setting for the prevention of operative venous stasis and its sequelae, postoperative DVT. A new sequential intermittent pneumatic device, the "Veno-Press", was applied on 20 volunteers of whom 10 were undergoing surgery unrelated to the lower limbs, during the pre-anesthesia and during general anesthesia. The venous velocity patterns over the femoral vein were depicted via duplex scanning under different pressure and rhythm settings of the device. The "Veno-Press" induced a marked augmentation in venous blood velocity flow. A further 10-30% augmentation was noted when the patients were under general anesthesia, as well as a 10-30% increase in the femoral vein diameter. None of the patients developed postoperative DVT. This device is a very efficient tool for augmentation of venous blood velocity, especially during general anesthesia. Its effectiveness is most probably the result of the compressive action over the relaxed--and hence enlarged--capacitant veins of the anesthetized patient. We suggest that the "Veno-Press", if properly timed, is very efficient in venostasis prevention, leading presumably to a decline in the occurrence of DVT and pulmonary embolisms in the surgical patient.

Anesthesia, General↗
PubMed1995

Primary long-standing chylous reflux into skin: combined operative and non-operative treatment.

Chylous discharge into cavities or skin is rare and usually arises after operations in the vicinity of the cisterna chyli (secondary chylous reflux). When chylous discharge is primary, however, chylous reflux has usually been present since birth probably as a consequence of obstruction to lymph flow at or above the cistern chyli. We report a patient who had had chylous reflux into lacerated skin in a lymphedematous thigh for more than 30 years. The condition was successfully managed using both operative and non-operative methods.

Combined Modality Therapy↗
PubMed1994

Prenatal diagnosis of congenital dysgranulopoietic neutropenia.

Congenital dysgranulopoietic neutropenia is a severe life-threatening disease characterized by specific dysmorphic granulocytes. Prenatal diagnosis of congenital neutropenia was reported first in 1983. In 1989 we reported a family with congenital dysgranulopoietic neutropenia in two siblings (one male and one female); in 1992 the mother became pregnant and prenatal diagnosis was performed by cordocentesis. The results we obtained from the fetus at risk enabled us to suggest that it was not affected, and we advised the parents that the pregnancy could continue: a healthy female was born. The neutrophil count at 2 and 4 months was normal.

Consanguinity↗
PubMed1994

Diversity of beta-globin mutations in Israeli ethnic groups reflects recent historic events.

We characterized nearly 500 beta-thalassemia genes from the Israeli population representing a variety of ethnic subgroups. We found 28 different mutations in the beta-globin gene, including three mutations (beta S, beta C, and beta O-Arab) causing hemoglobinopathies. Marked genetic heterogeneity was observed in both the Arab (20 mutations) and Jewish (17 mutations) populations. On the other hand, two ethnic isolates--Druze and Samaritans--had a single mutation each. Fifteen of the beta-thalassemia alleles are Mediterranean in type, 5 originated in Kurdistan, 2 are of Indian origin, and 2 sporadic alleles came from Europe. Only one mutant allele--nonsense codon 37--appears to be indigenous to Israel. While human habitation in Israel dates back to early prehistory, the present-day spectrum of beta-globin mutations can be largely explained by migration events that occurred in the past millennium.

Alleles↗
PubMed1992

[Aortocaval fistula].

Aortocaval fistula is a rare phenomenon which has both acute and chronic clinical presentations. Its diagnosis and treatment are difficult and it presents a surgical challenge of the first degree, requiring intensive perioperative care. A patient with an aortocaval fistula is described. It was found during emergency operation for a ruptured abdominal aortic aneurysm.

Aged↗
PubMed1991

[Familial infantile myasthenia gravis].

The several forms of myasthenia gravis that occur in infancy include transient neonatal myasthenia, congenital myasthenia, and familial infantile myasthenia gravis. The latter is inherited in an autosomal recessive pattern. Severe episodes of respiratory distress are frequent in infancy, and are often provoked by mild respiratory infections. 2 sisters with congenital myasthenia gravis are described. Probably 2 other sisters died of the same disease, but no definite diagnosis was made in their cases.

Female↗
PubMed1991

[Evaluation of non-occurrence by TI-59 programmable calculator].

A TI-59 programmable calculator program is presented for calculating either risk probability, sample size or confidence level (given 2 of the 3 variables) in cases in which an event of concern did not occur, or as expressed mathematically, had zero numerators. Its main usefulness is as a tool for interpreting previously published data containing no adverse event of concern while contemplating medical alternatives. These conditions are not infrequent in rare medical events--either diseases or complications. However, applicability of the program extends beyond these confines, exemplified in experimental planning for considering expected sample size or in calculating certainty in terms of confidence level.

Mathematical Computing↗
PubMed1991

Ischemic venous thrombosis.

Eight patients were treated for ischemic venous thrombosis of the extremities. The patients were evaluated retrospectively concerning their history, clinical signs and symptoms, management and follow-up. Neoplastic disease and immobility were the major etiological factors. Once diagnosed, an urgent combined medical and surgical approach proved to be successful in all patients as far as restoration of blood flow to the limb was concerned.

Adult↗
PubMed1990

Imerslund syndrome with dolichocephaly.

Imerslund syndrome is a rare autosomal recessive disorder of megaloblastic anemia as a result of selective vitamin B12 malabsorption associated with proteinuria. An Arabic Muslim family is described, with three children who had inherited selective vitamin B12 malabsorption with proteinuria. Dolichocephaly was noted in all the male children of this family in association with congenital megaloblastic anemia and proteinuria. The findings of this anemia are compatible with Imerslund-Gräsbeck syndrome, and coexistence of this syndrome with dolichocephaly in a single family has not been previously reported.

Anemia, Megaloblastic↗