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Lashen SA, Shamseya MM, Madkour MA, Abdel Salam RM, Mostafa SS. β-arrestin-2 predicts the clinical response to β-blockers in cirrhotic portal hypertension patients: A prospective study. World J Hepatol 2022; 14:429-441. [PMID: 35317175 PMCID: PMC8891671 DOI: 10.4254/wjh.v14.i2.429] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 01/08/2022] [Accepted: 02/16/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Portal hypertension, a common complication associated with liver cirrhosis, can result in variceal bleeding, which greatly impacts patient survival. Recently, β-arrestin-2 has been shown to predict the acute hemodynamic response to nonselective β-blocker therapy for cirrhotic portal hypertension. However, more data is needed on the long-term effects of and changes in β-arrestin-2 following nonselective β-blocker therapy.
AIM To investigate the expression and role of β-Arrestin-2 in predicting the long-term response to nonselective β-blockers in cirrhotic portal hypertensive patients.
METHODS We prospectively enrolled 91 treatment-naïve patients with cirrhotic portal hypertension. Baseline clinical and laboratory data were obtained. Gastroscopy was performed for grading and treating varices and obtaining gastric antral biopsies. We measured the serum and antral expression of β-arrestin-2 and obtained Doppler measurement of the portal vein congestion index. Treatment with nonselective β-blockers was then started. The patients were followed up for 18 mo, after which they have undergone a repeat antral biopsy and re-evaluation of the portal vein congestion index.
RESULTS A higher serum level and antral expression of β-arrestin-2 was associated with longer bleeding-free intervals, greater reduction in the portal vein congestion index, and improved grade of varices. Among patients with a low β-arrestin-2 expression, 17.6% were nonselective β-blocker responders, whereas, among those with high expression, 95.1% were responders (P < 0.001). A serum β-arrestin-2 value ≥ 2.23 ng/mL was associated with a lower likelihood of variceal bleeding (90% sensitivity and 71% specificity). β-arrestin-2 expression significantly decreased after nonselective β-blocker therapy.
CONCLUSION β-arrestin-2 expression in cirrhotic portal hypertension predicts the clinical response to long-term nonselective β-blocker treatment. Serum β-arrestin-2 is a potential noninvasive biomarker for selecting the candidate patients for nonselective β-blockers.
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Affiliation(s)
- Sameh A Lashen
- Division of Hepatology and Gastroenterology, Faculty of Medicine, Alexandria University, Alexandria 21521, Egypt
| | - Mohammed M Shamseya
- Department of Experimental and Clinical Internal Medicine, Medical Research Institute, Alexandria 21561, Egypt
| | - Marwa A Madkour
- Department of Experimental and Clinical Internal Medicine, Medical Research Institute, Alexandria 21561, Egypt
| | - Radwa M Abdel Salam
- Department of Pathology, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt
| | - Sanaa S Mostafa
- Department of Pathology, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt
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Affiliation(s)
- Ragaa A. Ramadan
- Medical Research Institute Teaching Hospital, Alexandria University, Egypt
| | - Marwa A. Madkour
- Medical Research Institute Teaching Hospital, Alexandria University, Egypt
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Shamseya MM, Madkour MA. Rifaximin: A reasonable alternative for norfloxacin in the prevention of spontaneous bacterial peritonitis in patients with HCV-related liver cirrhosis. Alexandria Journal of Medicine 2019. [DOI: 10.1016/j.ajme.2015.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Mohammed M. Shamseya
- Department of Clinical and Experimental Internal Medicine, Medical Research Institute, University of Alexandria, EgyptDepartment of Clinical and Experimental Internal Medicine, Medical Research Institute, University of Alexandria, Egypt
| | - Marwa A. Madkour
- Department of Clinical and Experimental Internal Medicine, Medical Research Institute, University of Alexandria, EgyptDepartment of Clinical and Experimental Internal Medicine, Medical Research Institute, University of Alexandria, Egypt
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Lashen SA, Shamseya MM, Madkour MA, Aboufarrag GA. Tolerability and effectiveness of generic direct-acting antiviral drugs in eradication of hepatitis C genotype 4 among Egyptian patients. Liver Int 2019; 39:835-843. [PMID: 30549417 DOI: 10.1111/liv.14022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 09/19/2018] [Accepted: 12/02/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND We investigated tolerability and effectiveness of generic, less expensive direct antiviral drugs in the treatment of hepatitis C virus genotype 4 (HCV GT-4) in an Egyptian cohort. PATIENTS AND METHODS Retrospectively, we analysed data from 648 patients with HCV GT4 attending Alexandria Main University Hospital from January 2016 to May 2017 [488 treatment naïve/160 treatment-experienced/288 with chronic hepatitis/360 with cirrhosis]. Patients received generic sofosbuvir/ledipasvir (n = 168, treatment naïve = 136, treatment-experienced = 32) or sofosbuvir/daclatasvir (n = 480, treatment naïve = 352, treatment-experienced = 128) ± ribavirin. We assessed sustained virologic response 12 weeks after treatment, non-response, relapse, treatment discontinuation and drug adverse reactions. RESULTS An overall sustained virologic response 12 weeks after treatment was achieved in 97.8%, non-response in 0.6%, relapse in 0.3% and discontinuation of treatment in 1.3% of patients. Sofosbuvir/ledipasvir ± ribavirin regimen attained an overall sustained virologic response 12 weeks after treatment in 96.4% of patients (100% of treatment-experienced vs 95.6% of treatment naïve, P = 0.28), vs 98.3% for sofosbuvir/daclatasvir ± ribavirin regimen (100% of treatment-experienced vs 97.7% of treatment naïve, P = 0.08). No severe drug adverse events or deaths were reported except anaemia due to ribavirin. CONCLUSION Generic direct antiviral drugs used in treating Egyptian patients with HCV GT-4 demonstrated equal potency, safety and tolerability compared to original brands, with low cost which would help to provide treatment to a larger scale of patients.
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Affiliation(s)
- Sameh A Lashen
- Department of Internal Medicine, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Mohammed M Shamseya
- Department of Experimental and Clinical Internal Medicine, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Marwa A Madkour
- Department of Experimental and Clinical Internal Medicine, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Galal A Aboufarrag
- Department of Tropical Medicine, Faculty of Medicine, Al-Azhar University, Cairo, Egypt
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Salem AI, El-Taweel HA, Madkour MA, Abd El-Latif NF, Abd-Elrazeq ES. Irritable bowel syndrome in Egyptian patients: plausible risk factors and association with intestinal protozoa. Trop Doct 2019; 49:184-188. [PMID: 30885054 DOI: 10.1177/0049475519837112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The pathogenesis of irritable bowel syndrome (IBS) is not yet clear. Our study suggested parasitic infection and other plausible risk factors among Egyptian IBS patients. We studied 40 IBS patients diagnosed according to Rome III criteria (Group I), 40 with other gastrointestinal symptoms (Group II) and 40 healthy controls (Group III). Stool samples were examined using direct wet smear, sedimentation technique, trichrome stain and immune-chromatographic tests for Cryptosporidium parvum. IBS patients displayed a significantly greater percentage of Blastocystis hominis infection (45%) than non-IBS patients (20%) and healthy controls (10%). Dientamoeba fragilis was identified in two IBS patients. Detection of B. hominis was independent of demographic characters, IBS subtype, Helicobacter pylori infection or medications, but with a positive association with a history of antibiotic intake with IBS.
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Affiliation(s)
- Aziza I Salem
- 1 Professor, Parasitology Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Hend A El-Taweel
- 1 Professor, Parasitology Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Marwa A Madkour
- 2 Assistant Professor, Department of Experimental and Clinical Internal Medicine, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Naglaa F Abd El-Latif
- 3 Lecturer, Parasitology Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Ebtesam S Abd-Elrazeq
- 4 Assistant Lecturer, Department of Laboratories, Higher Institute of Medical Professions, University of Omar Almokhtar, Bayda, Libya
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Lashen SA, Shamseya MM, Madkour MA. Hepatocellular Carcinoma Occurrence/Recurrence after Direct-Acting Antivirals for Hepatitis C in Egyptian Cohort: Single-Center Experience. Dig Dis 2019; 37:488-497. [PMID: 31216532 DOI: 10.1159/000501072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/20/2019] [Indexed: 02/05/2023]
Abstract
BACKGROUND Conflicting data have been published about the risk of hepatocellular carcinoma (HCC) following direct-acting antivirals (DAAs). We investigated the incidence of HCC occurrence/recurrence after DAAs therapy. PATIENTS AND METHODS Retrospectively, we analyzed data of 392 patients with F3-4 fibrosis and cirrhosis treated by DAAs during the period from August 2015 to May 2018. In HCC-experienced patients, HCC treatment modality, and the duration between HCC management and DAAs initiation were recorded. In all patients, pretreatment clinicolaboratory evaluation, and imaging before, during and after DAAs were done. RESULTS De novo HCC occurred in 7.6% of naïve patients, while recurrence appeared in 28% of patients with previous HCC. Pretreatment alpha-fetoprotein was an independent predictor of HCC occurrence, while the time between HCC ablation and the beginning of DAAs was the only predictor of HCC recurrence (p < 0.001). Half of the patients who started DAAs before 6 months had HCC recurrence, while patients who started DAAs at ≥6 months had no recurrence (p< 0.0001). CONCLUSIONS Although HCC occurrence after DAAs was not high, recurrence was apparently high. Pretreatment alpha-fetoprotein is a predictor for de novo HCC. The time between HCC ablation and DAAs was the strongest predictor of recurrence.
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Affiliation(s)
- Sameh A Lashen
- Department of Internal Medicine, Faculty of Medicine, Alexandria, Egypt,
| | - Mohammed M Shamseya
- Department of Experimental and Clinical Internal Medicine, Medical Research Institute, University of Alexandria, Alexandria, Egypt
| | - Marwa A Madkour
- Department of Experimental and Clinical Internal Medicine, Medical Research Institute, University of Alexandria, Alexandria, Egypt
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Madkour MA, Smith LT, Smith GM. Preferential osmolyte accumulation: a mechanism of osmotic stress adaptation in diazotrophic bacteria. Appl Environ Microbiol 2010; 56:2876-81. [PMID: 16348295 PMCID: PMC184858 DOI: 10.1128/aem.56.9.2876-2881.1990] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A common cellular mechanism of osmotic-stress adaptation is the intracellular accumulation of organic solutes (osmolytes). We investigated the mechanism of osmotic adaptation in the diazotrophic bacteria Azotobacter chroococcum, Azospirillum brasilense, and Klebsiella pneumoniae, which are adversely affected by high osmotic strength (i.e., soil salinity and/or drought). We used natural-abundance C nuclear magnetic resonance spectroscopy to identify all the osmolytes accumulating in these strains during osmotic stress generated by 0.5 M NaCl. Evidence is presented for the accumulation of trehalose and glutamate in Azotobacter chroococcum ZSM4, proline and glutamate in Azospirillum brasilense SHS6, and trehalose and proline in K. pneumoniae. Glycine betaine was accumulated in all strains grown in culture media containing yeast extract as the sole nitrogen source. Alternative nitrogen sources (e.g., NH(4)Cl or casamino acids) in the culture medium did not result in measurable glycine betaine accumulation. We suggest that the mechanism of osmotic adaptation in these organisms entails the accumulation of osmolytes in hyperosmotically stressed cells resulting from either enhanced uptake from the medium (of glycine betaine, proline, and glutamate) or increased net biosynthesis (of trehalose, proline, and glutamate) or both. The preferred osmolyte in Azotobacter chroococcum ZSM4 shifted from glutamate to trehalose as a consequence of a prolonged osmotic stress. Also, the dominant osmolyte in Azospirillum brasilense SHS6 shifted from glutamate to proline accumulation as the osmotic strength of the medium increased.
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Affiliation(s)
- M A Madkour
- Plant Growth Laboratory and Department of Food Science and Technology, University of California, Davis, California 95616
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8
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Kassem HA, Hassan AN, Abdel-Hamid I, Osman G, El Khalab EM, Madkour MA. Wolbachia infection and the expression of cytoplasmic incompatibility in sandflies (Diptera: Psychodidae) from Egypt. Ann Trop Med Parasitol 2003; 97:639-44. [PMID: 14511562 DOI: 10.1179/000349803225001391] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A PCR-based method was used to screen four laboratory colonies of sandflies for Wolbachia infection. The colonies - one of Phlebotomus langeroni, one of P. bergeroti and two of P. papatasi - were all derived from sandflies collected in Egypt. Only one of the colonies, derived from P. papatasi collected in Sinai, was found infected. The sequence of the PCR product for this colony was identical to that previously reported for the Wolbachia in P. papatasi from Israel. The induction with tetracycline of cytoplasmic incompatibility (CI) in flies from the P. papatasi (Sinai) colony was then investigated, through reciprocal crosses between treated and untreated P. papatasi siblings. Partial CI expression was attained in the crosses involving antibiotic-treated (i.e. uninfected) females, whether the males used were infected with Wolbachia or had also been cleared of Wolbachia by antibiotic treatment. Most (75%) of the eggs oviposited by uninfected females that had been crossed with infected males, and most (58%) of those laid by uninfected females that had been crossed with uninfected males, failed to hatch. These results provide the first published evidence showing that Wolbachia infection in sandflies is advantageous to the insects. The failure to detect Wolbachia in one of the colonies derived from Egyptian P. papatasi or in the colonies derived from Egyptian P. bergeroti and P. langeroni may indicate that the inter- and intra-specific spread of Wolbachia is discontinuous, even within one country.
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Affiliation(s)
- H A Kassem
- Institute of Environmental Studies and Research, Ain Shams University, Abbassia, Postal Code 11566, Cairo, Egypt.
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9
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Shamloul AM, Abdallah NA, Madkour MA, Hadidi A. Sensitive detection of the Egyptian species of sugarcane streak virus by PCR-probe capture hybridization (PCR-ELISA) and its complete nucleotide sequence. J Virol Methods 2001; 92:45-54. [PMID: 11164917 DOI: 10.1016/s0166-0934(00)00272-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A rapid and sensitive assay for the specific detection of Sugarcane streak virus (SSV) using PCR-probe capture hybridization (PCR-ELISA) was developed. Nucleic acids suitable for PCR were extracted from SSV-infected tissue using organic solvents or Fast DNA kit. SSV cDNA was amplified using viral specific primers and the amplified SSV cDNA (amplicon) was DIG-labelled during the amplification process. The amplicon was then detected in a colorimetric hybridization system by a microtiter plate using a biotinylated cDNA (22 nt), cDNA (789 nt) or cRNA (789 nt) capture probe. This system combines the specificity of molecular hybridization, the ease of the colorimetric protocol, and is 10-100 fold more sensitive than agarose gel electrophoretic analysis in detecting the amplified product. Long cDNA or cRNA capture probe was 2-7 fold more sensitive than the oligo cDNA probe for the detection. Complete nucleotide sequence of SSV from Naga Hammady, Egypt, revealed that SSV-EG is a new species of SSV that shares 66% nucleotide identity with the virus species from Natal, South Africa.
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Affiliation(s)
- A M Shamloul
- Fruit Laboratory, Agricultural Research Service, US Department of Agriculture, Beltsville, MD 20705, USA.
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10
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Mohammed A, Douches DS, Pett W, Grafius E, Coombs J, Li W, Madkour MA. Evaluation of potato tuber moth (Lepidoptera: Gelechiidae) resistance in tubers of Bt-cry5 transgenic potato lines. J Econ Entomol 2000; 93:472-476. [PMID: 10826202 DOI: 10.1603/0022-0493-93.2.472] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The potato tuber moth, Phthorimaea operculella (Zeller), in tropical and subtropical countries, is the most destructive pest of potato, Solanum tuberosum L. The larvae attack foliage and tubers in the field and in storage. The purpose of this study was to evaluate the efficacy of a Bt-cry5 transgene to control the potato tuber moth in tuber tissues. Tuber bioassays using stored (11-12 mo old) and newly harvested tubers of Bt-cry5-Lemhi Russet and Bt-cry5-Atlantic potato lines showed up to 100% mortality of 1st instars. Mortality was lowest in the newly harvested tubers of Bt-cry5-Atlantic lines (47.1-67.6%). Potato tuber moth mortality was 100% in the Bt-cry5-Spunta lines that were transformed with Bt-cry5 gene controlled by the CaMV 35S promoter (pBIML5 vector) and in 2 of 3 lines transformed with Bt-cry5 gene controlled by the Gelvin super promoter (pBIML1 vector). The transgenic Spunta lines expressing Bt-cry5 controlled by the patatin promoter (pBMIL2 vector) showed the lowest tuber moth mortality (25.6 and 31.1%). The Bt-cry5 transgenic lines with high tuber expression of B. thuringiensis have value in an integrated pest management system to control potato tuber moth.
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Affiliation(s)
- A Mohammed
- Agricultural Genetic Engineering Research Institute, Giza, Egypt
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11
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Madkour MA, Bedoya L, Fouad-Tarazi FM. Reduced vascular excitatory responses to cardiopulmonary unloading in hypertensive patients with left ventricular diastolic dysfunction. Clin Auton Res 1992; 2:243-55. [PMID: 1392543 DOI: 10.1007/bf01819545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Physiological consequences of altered peak left ventricular diastolic filling rate in hypertension have not yet been fully assessed. The hypothesis that altered left ventricular diastolic filling rate interferes with inhibitory cardiopulmonary reflexes was tested. Normalized peak left ventricular diastolic filling rate was calculated from radionuclide ventriculography. Haemodynamic changes during lower body negative pressure (-5 to -40 mmHg) in nine hypertensive patients with slow normalized left ventricular filling rate (Group A) were compared with 16 hypertensive patients with normal normalized peak left ventricular diastolic filling rate and ten normal volunteers of the same age group. Baseline total peripheral resistance was higher in essential hypertension compared to normals but did not differ significantly between the two hypertensive groups. For data analysis, the levels of lower body negative pressure were grouped as low levels of -5 to -10, and -15 to -20 mmHg, an intermediate level of -25 mmHg, and high levels of -30 to -40 mmHg; the change in total peripheral resistance (from baseline) was less prominent in Group A compared to Group B and to normals (-1.4 +/- 1.7 [SE], -0.06 +/- 1.4, 1.1 +/- 1.2 and 4.5 +/- 2 u.M2 in Group A at the four consecutive levels of lower body negative pressure vs. 0.9 +/- 0.7, 3.8 +/- 0.9, 7.2 +/- 1.6, and 8.2 +/- 1.4 in Group B, and 2.0 +/- 0.7, 3.3 +/- 0.8, 4.9 +/- 0.8, and 5.6 +/- 1.0 in normals). The reductions in central venous pressure and in pulmonary wedge pressure were not significantly different among the three groups at the different levels of lower body negative pressure, but the reduction in cardiac output was smaller in patients with reduced dv/dt ratio than in the other two groups. The responses to the cold pressor test were similar in all subjects. We conclude that patients with essential hypertension and diastolic dysfunction have impaired total peripheral resistance responses to lower body negative pressure. This abnormality may reflect an alteration in cardiac baroreflexes secondary to left ventricular diastolic dysfunction, an influence of baseline sympathetic activity on the observed vascular responsiveness to lower body negative pressure, or primary differences among groups in the changes in cardiac output induced by similar levels of lower body negative pressure.
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Affiliation(s)
- M A Madkour
- Department of Heart and Hypertension Research, Cleveland Clinic Foundation, OH 44195-5069
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12
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Smith LT, Smith GM, Madkour MA. Osmoregulation in Agrobacterium tumefaciens: accumulation of a novel disaccharide is controlled by osmotic strength and glycine betaine. J Bacteriol 1990; 172:6849-55. [PMID: 2254260 PMCID: PMC210802 DOI: 10.1128/jb.172.12.6849-6855.1990] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We have investigated the mechanism of osmotic stress adaptation (osmoregulation) in Agrobacterium tumefaciens biotype I (salt-tolerant) and biotype II (salt-sensitive) strains. Using natural-abundance 13C nuclear magnetic resonance spectroscopy, we identified all organic solutes that accumulated to significant levels in osmotically stressed cultures. When stressed, biotype I strains (C58, NT1, and A348) accumulated glutamate and a novel disaccharide, beta-fructofuranosyl-alpha-mannopyranoside, commonly known as mannosucrose. In the salt-sensitive biotype II strain K84, glutamate was observed but mannosucrose was not. We speculate that mannosucrose confers the extra osmotic tolerance observed in the biotype I strains. In addition to identifying the osmoregulated solutes that this species synthesizes, we investigated the ability of A. tumefaciens to utilize the powerful osmotic stress protectant glycine betaine when it is supplied in the medium. Results from growth experiments, nuclear magnetic resonance spectroscopy, and a 14C labeling experiment demonstrated that in the absence of osmotic stress, glycine betaine was metabolized, while in stressed cultures, glycine betaine accumulated intracellularly and conferred enhanced osmotic stress tolerance. Furthermore, when glycine betaine was taken up in stressed cells, its accumulation caused the intracellular concentration of mannosucrose to drop significantly. The possible role of osmoregulation of A. tumefaciens in the transformation of plants is discussed.
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Affiliation(s)
- L T Smith
- Plant Growth Laboratory, University of California, Davis 95616
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13
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Bravo E, Fouad-Tarazi F, Rossi G, Imamura M, Lin WW, Madkour MA, Wicker P, Cressman MD, Saragoca M. A reevaluation of the hemodynamics of pheochromocytoma. Hypertension 1990; 15:I128-31. [PMID: 2298468 DOI: 10.1161/01.hyp.15.2_suppl.i128] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We examined the hemodynamic features of 24 untreated patients with surgically proven pheochromocytoma during steady-state periods and compared them with 24 untreated essential hypertensive patients individually matched for sex, age, body surface area, and arterial blood pressure. We found that, despite having 10-fold higher levels of circulating catecholamines, pheochromocytoma patients have hemodynamic characteristics similar to patients with essential hypertension and that, in individual patients, the ratio of circulating norepinephrine to epinephrine had no relation to the hemodynamic profile. In both groups, increased total peripheral resistance is primarily responsible for maintenance of hypertension. These results suggest that, unlike the acute administration of catecholamines, long-term exposure to high levels of circulating catecholamines does not produce hemodynamic responses characteristic of this group of compounds. This might be due in part to desensitization of the cardiovascular system to catecholamines and might explain the clinical observation that some patients can be completely asymptomatic despite harboring an actively catecholamine-secreting pheochromocytoma.
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Affiliation(s)
- E Bravo
- Cleveland Clinic Foundation, Department of Heart and Hypertension Research, Ohio 44195-5069
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14
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Abstract
Aortic compliance is a major determinant of systolic blood pressure and of impedance to left ventricular ejection. However, little is known about its regulating factors. To assess the effects of preload and adrenergic activity on aortic compliance, we studied 10 normal subjects and nine untreated hypertensive patients at rest and during lower body negative pressure. Aortic compliance was measured invasively from the diastolic decay of the aortic pressure tracing and systemic vascular resistance. Preload was decreased stepwise by lower body negative pressure (-5 to -40 mm Hg) while adrenergic activity was assessed by the change in plasma norepinephrine at a maximum level of negative pressure suction. At rest, aortic compliance was lower in hypertensive subjects compared with its value in normal individuals (0.048 +/- 0.012 [SD] versus 0.071 +/- 0.009 units, p less than 0.001) but correlated inversely with systolic blood pressure in both groups (r = -0.64 in normotensive individuals, r = -0.83 in hypertensive subjects, r = -0.88 for the whole group, p less than 0.001 for all). Whereas resting pulmonary wedge pressure was higher in hypertensive subjects compared with normal individuals (16 +/- 4 [SD] versus 11 +/- 3 mm Hg, p less than 0.05), resting plasma norepinephrine levels were not different between the two groups (261 +/- 139 versus 251 +/- 103 pg/ml). Neither of these two resting indices correlated with baseline aortic compliance in both normotensive individuals and hypertensive patients. During lower body negative pressure (LBNP), cardiac filling pressure (right atrial pressure and pulmonary wedge pressure) as well as cardiac output decreased in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M A Madkour
- Department of Heart and Hypertension, Cleveland Clinic Foundation, OH 44195-5069
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15
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Abstract
We examined the response of total peripheral resistance to low levels of lower-body negative pressure (-15 to -20 mmHg) in two groups of hypertensive patients, one with a reduced index of left ventricular filling and the other with normal left ventricular filling characteristics. These groups were compared with a group of normal volunteers of the same age range. Total peripheral resistance increased significantly from corresponding baseline values both in the normal volunteers and in the hypertensives with a normal diastolic function, but the hypertensives with a decreased diastolic function showed a non-significant change in total peripheral resistance. We suggest that left ventricular diastolic dysfunction in hypertension may be associated with an impairment in cardiopulmonary reflexes, and therefore may influence peripheral vascular regulation.
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Affiliation(s)
- M A Madkour
- Department of Heart and Hypertension Research, The Cleveland Clinic Foundation, Ohio 44195-5069
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16
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Abstract
The left ventricular (LV) diastolic filling rate has been reported to be reduced in hypertensive patients. To investigate the possible influence of altered LV diastolic function in hypertension on peripheral vascular regulation, hemodynamic measurements were obtained in 16 hypertensive patients in the resting supine position and during head-up tilt. The study population included seven men and nine women with an age range of 30 to 62 years (mean, 49.5 years +/- 10.6). Measurements included LV peak filling rate (+dv/dt), LV peak ejection rate (-dv/dt), LV ejection fraction, heart rate, total peripheral resistance, stroke volume, and cardiac index. Moreover, we calculated the ratio relating left ventricular filling rate to left ventricular ejection rate (+dv/dt/-dv/dt) because a complex interaction between ventricular contraction and relaxation is well recognized. We observed that in patients with slow diastolic filling rate (ratio +dv/dt/-dv/dt less than 0.9), the increase in total peripheral resistance in response to head-up tilt was less marked than in those with normal LV filling rate (+dv/dt/-dv/dt greater than or equal to 0.9), whereas changes in stroke volume during tilt were not statistically different between the two groups. Conversely, supine resting cardiac index and total peripheral resistance was not significantly different among groups. We conclude that abnormal diastolic filling is associated with abnormal cardiovascular adjustment to changes in body posture. We suggest that the altered response to head-up posture is related to decreased sensitivity of low pressure receptors in the cardiopulmonary area as a result of impaired LV diastolic function.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M A Madkour
- Department of Heart and Hypertension Research, Cleveland Clinic Foundation, OH 44195-5069
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Abstract
The objective was to determine the adulteration of fresh milk with reconstituted full fat milk powder. The ultra violet and visible spectra (700 to 240 nm) indicated two empirical parameters which are used to detect and quantify adulteration. Each parameter was calibrated against standards of adulteration and then tested against samples of known adulteration. One parameter, tested against two known series (5, 10, 20, 40 and 80% adulteration) gave the best correlation (coefficient of variation, 2.9%) between 20 and 60% adulteration. Correlation decreased at 80% adulteration (coefficient of variation 6.7%) and at 0 to 20% adulteration (coefficient of variation 35.9%). The second parameter, used in the range of 0 to 10% adulteration, when tested against 14 known samples gave results with an average of 12.5% below the true values. Sensitivity was 2.5% added reconstituted milk powder. The effect of low fat values (less than 2.3%) is discussed and a correction factor derived. The method when tested against 12 known samples gave the correct result in all cases within the limitations of the method; 4 commercial samples of milk were also analyzed.
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Ibrahim MM, Emile H, Madkour MA, el-Said G. Contractile performance following regression of left ventricular hypertrophy in hypertensive patients. J Hypertens Suppl 1985; 3:S465-7. [PMID: 2856768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The left ventricular end systolic stress-end systolic dimension (ESS-ESD) relation was used to assess the effect of regression in left ventricular hypertrophy on myocardial contractility in 14 hypertensive patients (mean age 47 years) treated with guanfacine (a sympatholytic central alpha-adrenergic agonist) for 10 weeks. Echocardiography (M-mode under two-dimensional guidance) was used to determine left ventricular dimensions, posterior wall thickness (PWT) and septal thickness (ST) before and during the last week of therapy. Left ventricular mass (LVM) expressed as cross-sectional area (CSA) and meridianal wall stress at end systole were derived. Echocardiography was carried out at rest and during i.v. infusion of sodium nitroprusside to alter left ventricular afterload. A minimum of four systolic arterial pressure-ESD points were available for analysis and the value for the slope ESS-ESD was calculated for each patient. Guanfacine produced a significant decrease (P < 0.005) in arterial pressure, wall thickness and CSA. The linear ESS-ESD slope was similar in patients with and without left ventricular hypertrophy and did not change in the whole group or in four patients who had a decrease in CSA of > 10%. It is concluded that guanfacine can induce regression of left ventricular hypertrophy in hypertensive patients and that a decrease in LVM does not influence the intrinsic contractile performance of the left ventricular.
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Abstract
1. Seventeen male patients with essential hypertension were studied after 4 weeks of placebo and after 8 weeks of beta-adrenoceptor-blockade therapy with atenolol (100 mg/kg). 2. The influence of the following factors on left ventricular wall thickness and left ventricular mass index as determined by echocardiography was examined: patient's age, duration of hypertension, arterial pressure, blood pressure variability, supine heart rate, maximal exercise heart rate, left ventricular wall stress and 24 h urinary catecholamines. 3. Left ventricular mass index was related to systolic blood pressure (r = 0.54, P less than 0.05) and to extent of increase in heart rate with maximal exercise (r = 0.62, P less than 0.05). No significant correlation was present between mass index and other variables. 4. After atenolol therapy, left ventricular mass index decreased by 14 g/m2 (12%). Changes in mass were related to its initial value (r = 0.69, P less than 0.01) and to % change in wall stress (r = 0.64, P less than 0.05). Patients who had a decrease in mass index of 10% or greater had an initially lower diastolic pressure (P less than 0.001). Other factors did not appear to influence significantly the regression of hypertensive left ventricular hypertrophy.
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Abstract
1. Atenolol (100 mg/day) was given to 12 hypertensive patients for 8 weeks, and its effects on mean arterial pressure, cardiac index and ejection phase indices of myocardial performance were examined by echocardiography. 2. Echocardiographic studies were made before treatment after 4 weeks on placebo and repeated after 4 and 8 weeks of atenolol therapy. Mean arterial pressure fell by 14 and 21% after 4 and 8 weeks respectively. Cardiac index fell by 22 and 20%, and stoke index fell by 11 and 7%. Calculated peripheral resistance did not change significantly. 3. Ejection phase indices, namely fractional shortening, ejection fraction and normalized mean rate of circumferential fibre shortening, did not change. End-diastolic volume index did not change and there was no relationship between changes in heart rate and end-diastolic volume index. 4. The study shows that atenolol in the resting state has no effect on certain echocardiographic indices of left ventricular function when given orally to hypertensive patients with normal left ventricular size and function. The reduction in cardiac and stroke indices were presumably secondary to a decrease in cardiac venous filling.
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Abstract
No information is available about the effects of oral atenolol, a cardioselective beta-adrenergic blocking agent with no intrinsic sympathomimetic activity, on left ventricular function. Atenolol, 100 mg/day, was given to 12 hypertensive patients for 8 weeks, and its effects on mean arterial pressure (MAP), cardiac index (CI) and ejection indexes of myocardial performance were examined by echocardiography. Echocardiographic studies were performed before treatment, after 4 weeks of placebo, and repeated after 4 and 8 weeks of atenolol therapy. MAP fell by 14% and 21% after 4 and 8 weeks, respectively. CI fell by 22% and 20% and stroke index (SI) fell by 11% and 7%. Calculated peripheral resistance did not change significantly. Fractional shortening, ejection fraction and normalized mean rate of circumferential fiber shortening did not change. The normalized mean posterior wall velocity decreased after 4 weeks but returned to pretreatment levels after 8 weeks. The septal velocity increased after 8 weeks. End-diastolic volume index (EDVI) did not change, and there was no relationship between changes in heart rate and EDVI. The study shows that atenolol in the resting state has no effect on certain echocardiographic indexes of left ventricular (LV) function when given orally to hypertensive patients with normal LV size and function. The reduction in CI and SI were presumably secondary to a decrease in cardiac venous filling.
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Ibrahim I, Hamdi Y, Tolba MN, Madkour MA. Bactericidal effect of acrylic acid esters. Zentralbl Bakteriol Parasitenkd Infektionskr Hyg 1976; 131:661-4. [PMID: 827872 DOI: 10.1016/s0044-4057(76)80028-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The antibacterial effect of p-Cl, p-Br, p-CH3, O-NO2, M-NO2, and p-NO2 substitutions of dimethylaminoethyl-alpha-phenyl-cinnamate on Bacillus subtilis, Sarcina lutea, and Escherichia coli was studied. The compounds were found to be more active against B. subtilis and S. lutea than against E. coli. The NO2 group in the para position was found to have the highest activity compared with the meta and ortho positions.
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