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Biomedical subjects

A Ahmed

Publications and source records attributed to A Ahmed.

At least 145 records · Page 8Linked to original sources

Anesthetic management of high-risk cardiac patients undergoing noncardiac surgery under the support of intraaortic balloon pump.

Patients with severely impaired left ventricular function, an uncorrectable coronary artery disease, and a recent myocardial infarction are at high risk of cardiac complications after major noncardiac surgery. We present two patients with extensive three-vessel coronary artery disease who underwent intraperitoneal surgery under the support of intraaortic balloon pump (IABP). In one patient, the IABP was inserted urgently because of the development of chest pain with significant ST depression on arrival in the operating room, and the other patient was managed with prophylactic IABP. There were no intraoperative or postoperative cardiac events in either patient. Thus, IABP should be considered in the perioperative management of patients with severe cardiac diseases.

Aged↗

Overview of interferon therapy for chronic hepatitis C.

The future therapy for chronic hepatitis C will probably include measures to decrease hepatocellular injury along with multidrug combinations, including inhibitors of the hepatitis C viral protease, helicase, or polymerase to reduce serum levels or eradicate HCV RNA. The results of recently concluded trials of IFN-alpha 2b plus ribavirin combination therapy have shown a twofold improvement in the biochemical and virologic response rates and superiority by other measures of efficacy with an acceptable safety profile. In view of these results, new guidelines for the management of chronic HCV infection are appropriate (Fig. 1).

Antiviral Agents↗

Treatment strategies for chronic hepatitis C: update since the 1997 National Institutes of Health Consensus Development Conference.

The National Institutes of Health Consensus Development Conference on the management of hepatitis C, which took place in March 1997 and was published in September 1997, established guidelines for the diagnosis and management of chronic hepatitis C. The recommended treatment of chronic hepatitis C virus (HCV) infection is interferon alpha (or equivalent) 3 MIU three times per week for 12 months, in patients showing response to therapy after 3 months. Patients with the greatest risk for progression to cirrhosis (i.e. persistently elevated alanine aminotransferase levels, detectable serum HCV-RNA and liver biopsy showing portal or bridging fibrosis and at least moderate inflammation and necrosis) are recommended as candidates for therapy. The indication for therapy is less obvious in patients with milder histological changes, compensated cirrhosis and age less than 18 years or older than 60 years. Treatment is not indicated for patients with persistently normal aminotransferases or decompensated cirrhosis. This review outlines the background studies that led to the recommendations of the National Institutes of Health for the treatment of chronic hepatitis C and reviews newer evolving treatment strategies over the past year. In particular, the results of studies exploring treatment options for relapsers and non-responders to prior interferon therapy and the reported results to date on the safety and efficacy of combination therapy with interferon plus ribavirin are highlighted. Although aggressive suppression of HCV-RNA with induction therapy (daily and/or higher doses) or long-acting pegylated interferon preparations may improve the current results of therapy, few data are yet available. Finally, the treatment of chronic hepatitis C with protease inhibitors holds promise but has yet to reach the stage of clinical trials.

Adolescent↗

Immunohistochemical localization of vascular endothelial growth factor (VEGF) and its two specific receptors, Flt-1 and KDR, in the porcine placenta and non-pregnant uterus.

Placental angiogenesis and growth are crucial elements in embryonic and later fetal development. Vascular endothelial growth factor (VEGF) and its specific receptors Flt-1 (VEGFR-1) and KDR (VEGFR-2) compose potent ligand receptor systems involved in angiogenesis and microvascular hyperpermeability. In the present immunohistochemical study, VEGF, Flt-1 and KDR were localized in uterus of cyclic non-pregnant pigs and in the porcine epitheliochorial placenta throughout gestation. Emphasis was placed on early gestational stages, where morphological studies have demonstrated extensive angiogenesis during initial placentation. The results revealed a high correlation in spatiotemporal distribution between the ligand and its receptors and a surprising demonstration of VEGF receptors in several non-endothelial cells. In non-pregnant pigs, VEGF, Flt-1 and KDR exhibited moderate to intense staining in uterine luminal epithelium and smooth muscle cells of the vessel walls. Endothelial cells of arteries and arterioles revealed labelling for Flt-1 and KDR, whereas the uterine glandular epithelium displayed intense KDR immunoreactivity at the late luteal phase. During gestation the uterine luminal epithelium demonstrated weak ligand and receptor immunostaining in the first half of early gestation [< or = 21 days post coitus (p.c.)], whereas later stages (> or = 21 days p.c.) displayed intense immunolabelling. Endothelial cells, smooth muscle cells of the vessel walls and uterine glandular epithelium revealed intense ligand and receptor immunoreactivity throughout gestation. In the fetal part of the placenta, VEGF, Flt-1 and KDR immunostaining displayed moderate to intense reactivity in the trophoblast throughout gestation, except during the second half of early gestation (days 21-30 p.c.). Fetal vessel walls were also immunopositive for VEGF, Flt-1 and KDR. Taken together, the results imply that the VEGF, Flt-1 and KDR ligand receptor system participate in the regulations of porcine placentation and that it in addition to its angiogenic properties also may influence the cellular differentiation and transport capabilities in uterine luminal as well as glandular epithelium and the trophoblast.

Animals↗

Management of childhood fractures in Anjouan Island, Comoros.

Limb fractures were reviewed in 489 children, 390 boys and 99 girls whose ages ranged between 2 days and 14 years (mean 8 yrs). Only 54 (11%) were caused by road traffic accidents; 435 (89%) were due to other causes. Fractures of the arm were seen in 332 (68%) children and there were leg fractures in 157 (32%), of which 155 (32%) were undisplaced and were treated by first aid. Closed reduction was performed on 138 (28%) children and 196 (40%) were treated by internal fixation. Infection and non-union occurred in 28 (14%) and 13 (7%), respectively. Re-operation was performed because of complications in 21 (11%).

Adolescent↗

Complications of traditional male circumcision.

The complications of traditional male circumcision were studied in 48 boys seen between January 1981 and December 1995. Their ages ranged from 3 days to 7 years (mean: 4 years). Haemorrhage, the commonest complication, was seen in 25 (52%) and infection in ten; one child had amputation of the penis. Other complications included meatal stenosis and urethro-cutaneous fistula. Sixty-four per cent of those with haemorrhage were neonates and their haemoglobin levels ranged between 6 and 15 g/dl. Three required blood transfusion, seven ligation of bleeding vessels and two required both. Overall, 21 patients required surgery and the average duration of hospital stay was 2-8 days. Most complications were seen between 1991 and 1995 when surgical fees had been introduced and the number of boys circumcized in our hospital decreased. We advocate the provision of adequate and safe facilities to cope with the increasing demand for circumcision in our society.

Age Factors↗

Etiology and treatment of community-acquired pneumonia in ambulatory children.

OBJECTIVES: To determine the etiology of community-acquired pneumonia in ambulatory children and to compare responses to treatment with azithromycin, amoxicillin-clavulanate or erythromycin estolate. METHODS: Ambulatory patients with pneumonia were identified at the Children's Medical Center of Dallas, TX. Children age 6 months to 16 years with radiographic and clinical evidence of pneumonia were enrolled and randomized to receive either azithromycin suspension for 5 days or a 10-day course of amoxicillin-clavulanate for those <5 years or erythromycin estolate suspension for those > or = 5 years. Blood culture was obtained in all patients and we obtained nasopharyngeal and pharyngeal swabs for culture and polymerase chain reaction (PCR) testing for Chlamydia pneumoniae and Mycoplasma pneumoniae and nasopharyngeal swabs for viral direct fluorescent antibody and culture. Acute and convalescent serum specimens were tested for antibodies to C. pneumoniae, M. pneumoniae and Streptococcus pneumoniae. Patients were evaluated 10 to 37 days later when repeat specimens for serology, PCR and culture were obtained. For comparative purposes healthy children attending the well-child clinic had nasopharyngeal and pharyngeal swabs obtained for PCR and culture for C. pneumoniae and M. pneumoniae. RESULTS: Between February, 1996, and December, 1997, we enrolled 174 patients, 168 of whom fulfilled protocol criteria for evaluation. There were 55% males and 63% were <5 years of age. All blood cultures were sterile and there was no correlation between the white blood cell and differential counts and etiology of pneumonia. Etiologic agents were identified in 73 (43%) of 168 patients. Infection was attributed to M. pneumoniae in 7% (12 of 168), C. pneumoniae in 6% (10 of 168), S. pneumoniae in 27% (35 of 129) and viruses in 20% (31 of 157). None of the swab specimens from 75 healthy control children was positive for C. pneumoniae or M. pneumoniae. Clinical response to therapy was similar for the three antibiotic regimens evaluated, including those with infection attributed to bacterial agents. CONCLUSION: Although a possible microbial etiology was identified in 43% of the evaluable patients, clinical findings and results of blood cultures, chest radiographs and white blood cell and differential counts did not distinguish patients with a defined etiology from those without a known cause for pneumonia. There were no differences in the clinical responses of patients to the antimicrobial regimens studied.

Adolescent↗

Tuberculous peritonitis: fatality associated with delayed diagnosis.

We describe a fatal case of tuberculous peritonitis and review the literature on the diagnostic modalities available to diagnose this entity. We suspect a delayed diagnosis resulted in the death of our patient. Today, the prompt diagnosis of an unknown ascitic process involves laparoscopy. A patient with unknown large volume ascites is the easiest and safest to laparoscope. Using a mini laparoscope, a bedside procedure with instantaneous return can be done. The newer noninvasive tests like determination of ascites fluid adenosine deaminase activity and polymerase chain reaction may be helpful in the prompt diagnosis of peritoneal tuberculosis. We recommend that patients with clinical presentation suggestive of peritoneal tuberculosis have either an aggressive diagnostic workup using high-yield tests or a trial of antituberculous therapy.

Aged↗

Estimating the true extent of cognitive decline in the old old.

OBJECTIVE: To measure cognitive change using a brief measure over a period of 9 years and to adjust for attrition in the sample. DESIGN: The Cambridge City over 75 Cohort (CC75C), a complete sample of the 75 years and older age group from five group general practices in the city of Cambridge with a systematic one-third of a further practice, all followed on four occasions. SETTING: Cambridge city, UK, the respondents' place of residence. PARTICIPANTS: A total of 2106 subjects were included at study entry. MEASUREMENTS: A brief interview, administered by a trained interviewer, containing a short cognitive scale and the Mini-Mental State Examination (MMSE) at baseline, 2.4 years, 6 years, and 9 years. RESULTS: Decline in MMSE scores occurred across the population and was greater in the oldest age groups. Attrition at later stages of the follow-up was associated with greater decline at earlier stages. Adjusting the results for loss to the sample leads to considerably higher estimates of decline, with the older age groups declining faster from lower levels. CONCLUSIONS: To date, cognitive decline in the very old has been considerably underestimated by longitudinal studies. If studies of population samples are to reflect the health and social needs of this frail group accurately, adjustments for the effect of attrition must be included before true decline can be estimated.

Age Factors↗

Lamivudine therapy for chemotherapy-induced reactivation of hepatitis B virus infection.

A 54-yr-old man with lymphoma and serological evidence of prior hepatitis B virus (HBV) infection, with detectable anti-HBc and anti-HBs, was treated with intensive chemotherapy. He had reactivation of HBV infection with acute hepatitis B manifest by detectable HBsAg and elevated aminotransferase levels >1000 IU/L. He was treated with lamivudine 150 mg daily and had prompt resolution of acute hepatitis B with return of elevated aminotransferases to normal, and initial loss of HBeAg with later loss of HBsAg. Lamivudine was continued during the course of further chemotherapy as prophylaxis against repeat HBV reactivation. Lamivudine is a nucleoside analogue that is a potent inhibitor of HBV reverse transcriptase and HBV replication. Lamivudine therapy should be considered for the treatment of HBV reactivation and might play a future role as preemptive therapy of HBV reactivation in patients with prior hepatitis B or chronic hepatitis B with inactive viral replication.

Acute Disease↗

Pharmacodynamics of vancomycin for the treatment of experimental penicillin- and cephalosporin-resistant pneumococcal meningitis.

With the emergence of beta-lactam antibiotic resistance among strains of Streptococcus pneumoniae, vancomycin has assumed an important role in the treatment of bacterial meningitis. Using the rabbit meningitis model, we evaluated the pharmacokinetics and pharmacodynamics of vancomycin in this setting. Animals were given 80 mg/kg of body weight daily in two or four divided doses to determine the penetration and activity of vancomycin in cerebrospinal fluid (CSF); each regimen was administered with and without dexamethasone. Mean peak (2 h) concentrations in CSF that were four- to eightfold higher than the minimum bactericidal concentration (MBC; 0.5 microgram/ml) for the pathogen were adequate for bacterial clearance. In both groups concentrations in CSF remained higher than the MBC for greater than 80% of the respective dosing intervals, and the penetration of vancomycin into CSF was 20%. Mean concentrations in CSF at 24 to 36 h of therapy were lower than those achieved during the first 12 h, consistent with a decline in the level of antibiotic entry into CSF as inflammation wanes. Rates of bacterial clearance were similar for the two regimens, and for all animals cultures of CSF were sterile by 36 h. The coadministration of dexamethasone significantly reduced the penetration of vancomycin into CSF by 29% and significantly lowered the rate of bacterial clearance during the first 6 h in animals receiving 20-mg/kg doses of vancomycin. For animals receiving 40-mg/kg doses, therapeutic peak concentrations in CSF were obtained even with steroid use, suggesting that the effect of steroids may be circumvented by the use of larger daily doses of vancomycin.

Animals↗

Effect of amlodipine therapy on the monoclonal antibody 3G8-induced calcium signal in polymorphonuclear leukocytes of hemodialysis patients.

Chronic renal failure is associated with impaired phagocytosis. This was attributed to the PTH-induced elevation of basal levels of [Ca2+]i of polymorphonuclear leukocytes (PMNLs) and to the small calcium transient induced by the ligation of the Fcgamma RIII receptors of these cells with 3G8 monoclonal antibodies. The blocking of the action of PTH on the PMNLs of patients with chronic renal failure by their treatment with a calcium channel blocker normalized the basal levels of [Ca2+]i of the PMNLs and reversed the defect in their phagocytic property. It is not known whether such therapy would also restore the calcium transient in the PMNLs in response to 3G8 monoclonal antibody to normal. We examined this issue in 12 normal subjects and 18 hemodialysis patients; 9 of them were treated with the calcium channel blocker, amlodipine, and the other 9 did not receive such therapy. The treatment with amlodipine normalized [Ca2+]i of PMNLs as well as the calcium transient in response to 3G8 monoclonal antibody and reversed the defect in their phagocytosis. It is concluded that chronic renal failure is associated with deranged calcium homeostasis of PMNLs which causes abnormalities in the function of Fcgamma RIII receptors and consequently results in impaired phagocytosis. Therapy with a calcium channel blocker can reverse all these derangements in metabolism and function of PMNLs.

Adult↗

Serologic and clinical response to treatment of systemic vasculitis and associated autoimmune disease with intravenous immunoglobulin.

BACKGROUND: Autoimmune vasculitides cannot always be controlled by steroids and immunosuppressive drugs. Intravenous immunoglobulin (IVIg) treatment was found beneficial in several vasculitides including systemic and organ-specific diseases. In this article we tested whether the beneficial clinical response of IVIg treatment in vasculitides was accompanied by a decrease in vasculitis-associated autoantibody levels. METHODS: Ten patients diagnosed as having vasculitis were treated with high-dose (2 g/kg) IVIg monthly, in a 5-day schedule. In all the patients, other therapeutic measures failed to control disease progression prior to IVIg treatment. Each patient received between 1 and 6 treatment courses. All patients were evaluated for the levels of 5 autoantibodies (Abs) related to vasculitis before and after each treatment course. RESULTS: In 6 out of the 10 patients, a beneficial clinical response followed IVIg treatment. Moreover, no treatment-related adverse effects were observed in any of the patients. Anti-myeloperoxidase antibodies and cytoplasmic-antineutrophil cytoplasmic antibodies levels decreased concomitantly with the clinical improvement observed in the patients with Churg-Strauss vasculitis and Wegener's granulomatosis, respectively. Levels of cytoplasmic-antineutrophil cytoplasmic antibodies (ANCA) with specificity for bacteridial/permeability-increasing protein and human lysosomal-associated membrane protein increased after each treatment course, but returned to normal values before the following one. CONCLUSIONS: When other therapeutic measures, such as immunosuppressive therapy, fails to control disease manifestations in patients with vasculitides, IVIg is a possible effective intervention method with a high response rate. IVIg probably exerted its effects on disease progression via different mechanisms. Among these mechanisms, a decrease in relevant Ab levels is often found (probably by anti-idiotypes in IVIg), and thus ANCA levels are expected to associate with disease activity.

Adult↗

Selectin blockade prevents antigen-induced late bronchial responses and airway hyperresponsiveness in allergic sheep.

Antigen challenge can elicit an allergic inflammatory response in the airways that involves eosinophils, basophils, and neutrophils and that is expressed physiologically as a late airway response (LAR) and airway hyperresponsiveness (AHR). Although previous studies have suggested that E-selectin participates in these allergic airway responses, there is little information concerning the role of L-selectin. To address this question, we examined the effects of administering an L-selectin-specific monoclonal antibody, DU1-29, as well as three small molecule selectin binding inhibitors, on the development of early airway responses (EAR), LAR and AHR in allergic sheep undergoing airway challenge with Ascaris suum antigen. Sheep treated with aerosol DU1-29 before antigen challenge had a significantly reduced LAR and did not develop postchallenge AHR. No protective effect was seen when sheep were treated with a nonspecific control monoclonal antibody. Treatment with DU1-29 also reduced the severity of the EAR to antigen. Similar results were obtained with each of the three small molecule selectin inhibitors at doses that depended on their L-, but not necessarily E-selectin inhibitory capacity. The inhibition of the EAR with one of the inhibitors, TBC-1269, was associated with a reduction in histamine release. Likewise, treatment with TBC-1269 reduced the number of neutrophils recovered in bronchoalveolar lavage (BAL) during the time of LAR and AHR. TBC-1269, given 90 min after antigen challenge also blocked the LAR and the AHR, but this protection was lost if the treatment was withheld until 4 h after challenge, a result consistent with the proposed time course of L-selectin involvement in leukocyte trafficking. These are the first data indicating that L-selectin may have a unique cellular function that modulates allergen-induced pulmonary responses.

Aerosols↗

A study of 20 SLE patients with intravenous immunoglobulin--clinical and serologic response.

OBJECTIVE: To test the clinical response of systemic lupus erythematosus (SLE) patients to intravenous immunoglobulins (IVIg), and whether the clinical response of IVIg treatment in SLE is accompanied by modification of SLE-associated autoantibodies/antibodies (Abs) and complement levels. METHODS: Twenty SLE patients were treated with high-dose (2 g/kg) IVIg monthly, in a 5-d schedule. Each patient received between 1-8 treatment courses. They were evaluated for the clinical response, Systemic Lupus Activity Measure (SLAM) score before and after IVIg, levels of antinuclear antibody (ANA), dsDNA (double-stranded DNA), SS-A or SS-B, ENA (extractable nuclear antigens), C3 and C4 levels before and after the treatment, and before and after each treatment course. RESULTS: A beneficial clinical response following IVIg treatment was noted in 17 out of 20 patients (85%). Few clinical manifestations responded more to treatment: arthritis, fever, thrombocytopenia, and neuropsychiatric lupus. In 9 patients evaluated before and after IVIg, mean SLAM score decreased from 19. 3+/-4.7 to 4+/-2.9 (P<0.0001). There was a tendency towards abnormal levels of complement and Abs before IVIg courses among the treatment responders compared with the non-responders, and similarly the former tended to have normalization of their abnormal levels more than the latter. These differences were found statistically significant only with respect to C4 and SS-A or SS-B levels before IVIg courses. CONCLUSION: IVIg has a high response rate among SLE patients. A combination of clinical manifestations, Abs and complement levels may aid in the future in predicting who among SLE patients will benefit more from IVIg treatment.

Adult↗