Circulating tumor cells clusters and their role in Breast cancer metastasis; a review of literature

Breast cancer is a significant and deadly threat to women globally. Moreover, Breast cancer metastasis is a complicated process involving multiple biological stages, which is considered a substantial cause of death, where cancer cells spread from the original tumor to other organs in the body-representing the primary mortality factor. Circulating tumor cells (CTCs) are cancer cells detached from the primary or metastatic tumor and enter the bloodstream, allowing them to establish new metastatic sites. CTCs can travel alone or in groups called CTC clusters. Studies have shown that CTC clusters have more potential for metastasis and a poorer prognosis than individual CTCs in breast cancer patients. However, our understanding of CTC clusters' formation, structure, function, and detection is still limited. This review summarizes the current knowledge of CTC clusters' biological properties, isolation, and prognostic significance in breast cancer. It also highlights the challenges and future directions for research and clinical application of CTC clusters.

Preferential osmolyte accumulation: a mechanism of osmotic stress adaptation in diazotrophic bacteria

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.

Wolbachia infection and the expression of cytoplasmic incompatibility in sandflies (Diptera: Psychodidae) from Egypt

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.

Sensitive detection of the Egyptian species of sugarcane streak virus by PCR-probe capture hybridization (PCR-ELISA) and its complete nucleotide sequence

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.

Evaluation of potato tuber moth (Lepidoptera: Gelechiidae) resistance in tubers of Bt-cry5 transgenic potato lines

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.

Reduced vascular excitatory responses to cardiopulmonary unloading in hypertensive patients with left ventricular diastolic dysfunction

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.

Osmoregulation in Agrobacterium tumefaciens: accumulation of a novel disaccharide is controlled by osmotic strength and glycine betaine

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.

A reevaluation of the hemodynamics of pheochromocytoma

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.

Preload, adrenergic activity, and aortic compliance in normal and hypertensive patients

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)

Alterations in cardiopulmonary receptors in hypertensive patients with impaired left ventricular filling

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.

Influence of left ventricular diastolic function on vascular and humoral responses to head-up posture in hypertension

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)

The determination of milk powder added to whole milk

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.

Contractile performance following regression of left ventricular hypertrophy in hypertensive patients

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.

Factors influencing cardiac hypertrophy in hypertensive patients

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.

Effect of atenolol on left ventricular function in hypertensive patients

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.

Effect of atenolol on left ventricular function in hypertensive patients

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.

Bactericidal effect of acrylic acid esters

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.