Implantation of novel small-diameter polyurethane vascular prostheses interposed in canine femoral and carotid arteries

OBJECTIVES: The performance of small-diameter (3-5-mm) vascular grafts still poses a challenge in the field of vascular surgery. We present here our preliminary experience with implanting unique small-sized polycarbonate urethane vascular grafts in 7 dogs. MATERIAL AND METHODS: Each animal was implanted with 4 interposition grafts, 2 femoral and 2 carotid. No anti-thrombotic medication was administered. Doppler sonography was performed at 3-month intervals to examine for patency and flow characteristics. Animals were sacrificed electively at 3, 6 and 12 months. RESULTS: At 3 months, all grafts were patent. After 6 months, 3 grafts occluded and at 1 year a further 6 grafts occluded. Hence 9 of 28 grafts occluded (67.9% patency). During the study, no correlation could be established between flow velocity or resistance index and occlusion. Histopathology showed intimal hyperplasia to be the cause of occlusion. CONCLUSIONS: Compared to literature data on small-diameter grafts in the same position, ADIAM's Biomechanical grafts performed clearly better. Compliance data suggest a correlation between elastic compliance and patency.     

Immune function in children with classical phenylketonuria and tetrahydrobiopterin deficiencies

BACKGROUND: An increased susceptibility to infections has been observed in some patients with phenylketonuria (PKU), which is not well known whether it is due to alterations of plasma essential amino acid concentrations or to some other factors. OBJECTIVE: This study is designed to establish B cell and T cell functions in 44 children with classical PKU and tetrahydrobiopterin (BH4) deficiencies and the effects of too high plasma phenylalanine (PA) concentrations (16.53 to 30.54 mg/dL) on the same parameters. DESIGN: B and T cell functions of 33 children with classical PKU (divided into two groups based on fasting mean plasma PA concentrations: Group-I = 20.9 +/- 3.7 mg/dL, Group-II = 3.8 +/- 1.02 mg/dL), and 11 children with BH4 deficiencies (Group III) were studied. The results were compared between the groups and referenced with previously reported values from healthy controls. RESULT: Delayed type skin hypersensitivity responses to purified protein derivative (PPD) in Group I and phytohaemagglutinin (PHA) in Group I, III were lower than the other groups and healthy controls. Plasma IgG and IgM concentrations of Group I was lower than the reference values. Although mean serum zinc and iron levels of all patients were lower than published values of healthy children, zinc and iron deficiencies in Group I, III were much more prominent as compared to Group II. CONCLUSION: The somewhat low plasma IgG concentrations in Group I may be related to the very high plasma PA levels, however the role of zinc deficiency as a causal factor can not be ruled out. BH4 metabolism defects do not appear to affect the same parameters. Impaired delayed skin hypersensitivity responses in Group I and III can be explained by severe serum zinc deficiency. In the light of this study, we conclude that in order to establish a causal relationship between PKU and immune functions, further studies need to be conducted after the correction of micro-nutrient status of such children.     

Polyostotic monosystemic calvarial and spinal langerhans' cell histiocytosis treated by surgery and chemotherapy

There are several treatment modalities for Langerhans' cell histiocytosis (LCH) of bone, formerly usually referred to as eosinophilic granuloma, including surgery, radiotherapy and chemotherapy. In spinal lesions, surgery is not recommended generally, because of the potential for reconstitution of vertebral height. We report a case of multifocal monosystemic LCH treated by surgery and chemotherapy for calvarial and spinal lesions. A 7-year-old boy was initially operated for an occipital monostotic LCH of bone. Then, he was treated by surgery for cervical and thoracic lesions, and by chemotherapy with vinblastine. The patient had no complaints at the 24-month follow-up. Although surgery is not recommended for spinal lesions in children with LCH of bone, short segmental fusion and internal fixation may be a suitable choice for selected cases, especially in children who are not likely to comply with activity restrictions and in those who it is difficult to follow up. The treatment must be planned according to the characteristics of the patient.     

Seroprevalence of hepatitis B and C in subjects admitted to a cardiology clinics in Turkey

A seroepidemiological study was conducted to assess the seroprevalence of hepatitis B surface antigen (HBs Ag) and antibodies to hepatitis C virus (Anti-HCV) in 14,196 patients hospitalized in our cardiology clinics. Threehundred and fifty five (355) patients (2.43%) were found to be positive for HBs Ag, a hundred and sixty six (166) patients (1.09%) were positive for Anti- HCV and ten patients (0.07%) were positive for both. The presence of HBs Ag and Anti-HCV was similar in patients living in rural and urban areas. The presence of risk factors was greater in the patients with Anti-HCV. The prevalences of HBs Ag and Anti-HCV were found to be comparable with those reported in other mediterranean countries in Europe.     

Antiviral potency of mistletoe (Viscum album ssp. album) extracts against human parainfluenza virus type 2 in Vero cells

Various extracts from the leaves of mistletoe (Viscum album L. ssp. album) were investigated for their antiviral activity on human parainfluenza virus type 2 (HPIV-2) growth in Vero cells. Plant extracts were prepared using distilled water, 50% ethanol, petroleum ether, chloroform and acetone. The 50% effective dose (ED(50)) of aqueous extract for HPIV-2 replication was 0.53 +/- 0.12 micro g/mL, and the antiviral index (AI), which was based on the ratio of the 50% inhibitory concentration (CD(50)) for host cell viability to the ED(50) for parainfluenza virus replication, was 10.05. The aqueous extract was found to be the most selective inhibitor. Furthermore, the aqueous extract at a concentration of 1 micro g/mL was found to inhibit HPIV-2 replication and the virus production was suppressed to more than 99% without any toxic effect on host cells. The chloroform extract was also found to be moderately active. In an effort to further analyse the mechanism of antiviral activity, the effectiveness of the aqueous extract on different steps of virus replication was examined. The antiviral activity could neither be attributed to the direct inactivation of the HPIV-2 nor to the inhibition of adsorption to Vero cells. The active aqueous extract has shown a dose-dependent antiviral activity on virus replication.     

Testicular tissue bleeding as an indicator of gonadal salvageability in testicular torsion surgery

OBJECTIVE: To investigate the reliability of using bleeding from the cut surface of testicular tissue during surgery for testicular torsion to assess testicular viability, compared with the duration of symptoms and preoperative findings on testicular Doppler ultrasonography (DUS). PATIENTS AND METHODS: The study comprised 19 children with testicular torsion who underwent surgery; all underwent DUS before surgery. During surgery the tunica vaginalis of the affected gonad was incised and a deep incision made through the medulla after obtaining a wedge biopsy for histological examination. After waiting up to 10 min to assess any fresh arterial bleeding from the cut surface, the patients were categorized using three grades; grade I (sufficient bleeding, i.e. bleeding or oozing when the biopsy was obtained); grade II (insufficient bleeding, no bleeding immediately after the incision but starting within 10 min); and grade III (no bleeding within 10 min). The final surgical decision on whether to save the testis was made according to the grade of testicular tissue bleeding; grade I and II testes were saved and grade III testes were removed. The biopsies were histopathologically examined and classified as haemorrhagic, necrotic or indeterminate. The patients were followed up at 15 days and at 1, 3, 6 and 12 months, with the affected testis examined using DUS. At the end of the study, the sensitivity and specificity of the duration of symptoms, characteristics of blood flow on DUS and grading of testicular tissue bleeding at surgery were calculated for predicting testis viability, using the histopathological diagnosis as the reference standard. RESULTS: The sensitivity, specificity, positive and negative predictive values were respectively 100%, 90%, 90% and 100% for a duration of symptoms of > 10 h, 78%, 80%, 78% and 80% for DUS findings, and 100%, 78%, 83% and 100% for testicular tissue bleeding in predicting gonad viability after torsion, respectively. CONCLUSION: Although the 10 h limit for the duration of symptoms seems a more accurate predictor of the fate of a twisted testis than were the other variables, testicular tissue bleeding may also be a good indicator of gonadal viability during surgery. The surgeon should wait up to 10 min after incising the testicular tissue deep to the medulla before deciding the type of surgery. In cases where bleeding from the cut surface is sufficient or insufficient (according to the proposed grading system), orchidopexy is the treatment of choice. The salvaged testes should be assessed during follow-up, especially in those who had had insufficient bleeding at surgery and/or a duration of symptoms > 10 h, to assess for any delayed damage to the untwisted testis. If no bleeding is seen during surgery the best option is to remove the affected testis.     

Febrile neutropenia as the presenting sign of appendicitis in an adolescent with acute myelogenous leukemia

The diagnosis and management of a surgical abdomen in patients with acute leukemia is quite difficult because of the complications and treatment of disease itself. A 13-year-old boy with acute myelogenous leukemia developed 2 episodes of febrile neutropenia during induction therapy. The second one was treated with a 5-day course of parenteral antimicrobial therapy, but the patient then presented with right lower quadrant abdominal tenderness, guarding, and rebound tenderness. Abdominal ultrasonography and computed tomography revealed appendicitis. Conservative medical management was unsuccessful, and appendectomy was performed 5 days after appendicitis was diagnosed. The patient's clinical manifestations resolved 5 days later. The case illustrates that fever may be the first manifestation of appendicitis in a child with acute myelogenous leukaemia who is neutropenic. Surgery is acceptable as first-line treatment in such cases.     

Comparison of the vasodilatory effect of nadroparin, enoxaparin, dalteparin, and unfractioned heparin in human internal mammary artery

The aim of this study was to investigate whether the low-molecular-weight heparins (LMWHs) (eg, nadroparin, enoxaparin, and dalteparin) cause a vasodilatory effect in human internal mammary artery (IMA) and to further compare its effect with unfractioned heparin (UFH). Samples of redundant IMA obtained from 20 patients undergoing a coronary artery bypass graft surgery were cut into 3-mm-wide rings and suspended in 20-mL organ baths. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. LMWHs (0.5-6 U/mL) caused a concentration-dependent relaxation in the endothelium-intact human IMA rings, which were precontracted with Phe (10(-6) M) (P < 0.05). The vasodilator potency of LMWHs seems to be nearly similar while the maximal effect produced by LMWHs was less pronounced compared with that produced by UFH. Removal of endothelium totally abolished the responses of human IMA to LMWHs as well as UFH (P < 0.05). LMWHs-induced vasodilator effect was significantly attenuated by Nomega-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) but not indomethacin (10(-5) M). Our results have shown that LMWHs cause a dose-dependent relaxation in human IMA but are less effective than that produced by UFH. The vasorelaxant effects induced by each of LMWH are nearly similar and seem to be via endothelium-dependent mechanisms, including generation of nitric oxide.     

Meningitis due to methicillin-resistant Staphylococcus aureus (MRSA): review of 10 cases

We evaluated retrospectively, 10 MRSA meningitis cases in our hospital that occurred between January 1999 and June 2004. All were post-neurosurgical and were considered to have hospital-acquired meningitis. Fever, leukocytosis, variable conscious levels were the most common findings. Six patients were treated with regimens including teicoplanin, and four with vancomycin. Mean duration of treatment was 23.5+/-18.8 days (range, 3-60 days). One patient died. In cases of MRSA meningitis, intravenous vancomycin is the mainstay of therapy. However, six of these 10 patients were successfully treated with regimens including teicoplanin, suggesting that this agent may be an alternative to vancomycin in the therapy of these cases.