Predictors of cord blood unit cell content in a volume unrestricted large series collections: a chance for a fast and cheap multiparameter selection model

Background

Cord blood plays a very important role in stem cell transplantation and therapy with an emerging implication also in regenerative medicine. The number of cells available in a single cord blood unit (CBU), in particular, the CD34+ and total nucleated cell (TNC) content influences the transplantation clinical outcome. We analysed a very large series of CBUs, collected for private banking without any specific volume restriction, to deeply investigate the best predictors of cord blood stem cells content.

Methods

Maternal and neonatal clinic laboratory data of a total 2583 UCBs were obtained from the InScientiaFides cord blood bank based in Republic of San Marino. Univariate and multivariate analysis were conducted to better interpret the data and to build a predictive model to select, the CBU with high CD34+ content.

Results

Our univariate analysis shows that seasonality and the geographical area affects the quality of umbilical cord blood. Gestational age, babie’s gender and birth weight have a positive correlation with CB TNC content. The babie’s birth weight affects positively also CD34+ content and CBU volume while the cesarean delivery affect the CB volume only. Our predictive model, based on multivariate analysis, shows that male babie’s, gestational age lower to 39 weeks, cesarean delivery and CBUs with a content of TNC higher than 3.44 × 10⁸ (group A) have a significant higher CD34+ content than group B (female babie’s, gestational age higher than 39 weeks and vaginal delivery). The group A have a 37.5% of CBUs with a concentration of CD34+  > 2 × 10⁶, while no CBUs with high concentration of CD34+ were detect in group B.

Conclusion

This study, conducted on a very large series of CBUs without any specific volume constraint, highlighted the prenatal and maternal factors that significantly influence the quality of the CBU collected. Specifically, it highlights that volume is not the best predictor of CD34+ CBU content; for this reason it cannot be taken into consideration alone for the analysis of the collected samples. Our final aim is to identify relevant factors, immediately available, that help to choice UCB with high CD34+ cell content, especially in simultaneous deliveries.

Microbiological Activity and Clinical Efficacy of a Colistin and Rifampin Combination in Multidrug-ResistantPseudomonas aeruginosaInfections

The aim of the study was to assess the microbiological activity and clinical efficacy of colistin and rifampin combination against multidrug-resistant (MDR) Pseudomonas aeruginosa infections. The antimicrobial activity of the colistin/rifampin combination was evaluated using the checkerboard and time-kill curve methods against different MDR P. aeruginosa strains. The combination of rifampin and colistin resulted fully (1 strain) or partially (5 strains) synergistic for 6/7 strains and minimum inhibitory concentrations (MICs) in combination were reduced to easily obtainable therapeutic levels. The time-kill curves showed that the combination was bactericidal against the strains tested. The clinical efficacy of the combination was tested in four patients with difficult-to treat infections (sepsis or pneumonia) caused by MDR P. aeruginosa. All infections were successfully treated. Our microbiological and clinical observations suggest that the addition of rifampin to colistin may result in a synergistic bactericidal combination that may be useful in patients with infections caused by MDR P. aeruginosa which are difficult to cure.

Total nucleated cells as a sole predictor of distinct targets of hematopoietic potential (CD34+ cells) in cord blood units: the results of a large series analysis in autologous cord blood units

BACKGROUND

Rapid identification of eligible cord blood units (CBUs) for banking is an important issue in hematopoietic stem cell procurement. Distinct contents of CD34+ cells in CBU can contribute to identify grafts that may be banked also for unrelated transplants or limited to family-directed or autologous use.

STUDY DESIGN AND METHODS

Considering thresholds of CD34+ cell content of 3 × 10(6) , 2 × 10(6) , and 1 × 10(6) CD34+ cells, we analyzed a consecutive series of 1309 CBUs. CBUs were collected for autologous banking without any volume-based preselection criteria. Predictors of distinct content of CD34+ cells have been assessed by receiver operating characteristic (ROC) curve analysis.

RESULTS

Median total nucleated cell (TNC) and CD34+ cell counts of the series were 6.97 × 10(8) (range, 0.36 × 10(8) -34.9 × 10(8) ) and 1.47 × 10(6) (0-20.56 × 10(6) ). Volumes ranged from 21 to 163 mL, with a median of 73.8 mL. For the CD34+ target of 1 × 10(6) , the best predictor was TNC count with a threshold of 6.63 × 10(8) ; volume results were less predictive with a value of 68.1 mL. For CD34+ targets of 2 × 10(6) and 3 × 10(6) , ROC curves confirmed a stronger predictive power of TNC, above the collected volume, with thresholds of 7.55 × 10(8) and 8.98 × 10(8) . ROC analysis by combining all predictors (TNC, volume, TNC(2) , volume(2) , age of mothers, types of delivery, birthweight) gave worse results than TNC count alone.

CONCLUSIONS

This analysis, carried out on a large, unrestricted CBU series, shows that TNC alone is the best predictor of distinct targets of hematopoietic potential with the chance to predict CBU potentially useful for unrelated recipients or limited for family-directed or autologous use.

Clinical and Microbiological Efficacy of Colistin Therapy Alone or in Combination as Treatment for Multidrug ResistantPseudomonas aeruginosaDiabetic Foot Infections with or Without Osteomyelitis

We retrospectively evaluated the safety and effectiveness of colistin alone or in combination with other antimicrobials in eight diabetic patients with severe diabetic foot infections due to multidrug resistant (MDR) Pseudomonas aeruginosa, complicated in 4 cases by osteomyelitis. All patients received colistin after other ineffective antimicrobial treatment, when MDR P. aeruginosa strains were isolated by cultural examination and together with a multidisciplinary care approach including revascularization, surgical debridement and adequate offloading. The mean duration of therapy was 72 +/- 52.9 days. Six out of 8 patients (75%) successfully benefited from colistin therapy, while 2 patients failed and/or experienced side effects that led to discontinuation of therapy. Serious adverse events (i.e. acute renal failure and pulmonary edema) were observed in 1 patient. Our data allow us to conclude that colistin, alone or in combination with other antimicrobials, is safe and effective when administered as part of a multidisciplinary approach, to promote healing of diabetic foot infection due to MDR P. aeruginosa.

High survival of frozen cells irradiated with gamma radiation

Cell storage in liquid nitrogen (LN) offers the most secure method of cell preservation even if cryopreserved cells are exposed to natural background of ionising radiation (IR). A lot of experiments have demonstrated that IR can induce damages in living cells, but only a little information regarding the response of cryopreserved cells is available. To investigate the effect of IR on frozen and unfrozen cells, peripheral blood mononuclear cells were directly irradiated at room temperature, then immediately frozen, or frozen and then irradiated in LN with different doses of gamma rays. After thawing, cells were incubated and death fraction was evaluated at different time points. Interestingly, the percentages of dead cells induced by IR gradually increased with both dose radiation and incubation time and were significantly lower for cells irradiated at -196°C than those irradiated at room temperature.

[Appropriateness of prescription of exercise stress test, echocardiography, Holter monitoring and vascular echography]

BACKGROUND

The aim of this study was to evaluate the appropriateness of prescription of non-invasive cardiological tests (exercise stress test, echocardiography, Holter monitoring and vascular echography), consecutively performed in our outpatient laboratory during 4 weeks.

METHODS

We collected the following data: the appropriateness of prescription (according to the Italian Federation of Cardiology guidelines); test indications; the prescribing physician (cardiologist/non-cardiologist); type of prescription (elective/urgent); clinical utility (useful/useless) and result (normal/abnormal) of each test.

RESULTS

We evaluated 960 prescriptions (320 exercise tests; 282 echocardiograms; 158 Holter tests; 200 vascular echographies). Test indications were appropriate (class I) in 37%, doubtfully appropriate (class II) in 39% and inappropriate (class III) in 24% of the cases. The appropriateness was slightly better for vascular echography and echocardiography (class I: 44% and 43%, respectively), markedly worse for exercise test (class I: 27%). The tests were considered useful in 46% and abnormal in 39% of the cases. Cardiologist-prescribed exams resulted more often appropriate (class I: 53 vs 30%; class II: 41 vs 38%; class III: 6 vs. 32%; p = 0.0001), more often useful (74 vs. 34%; p = 0.0001) and more frequently abnormal (43 vs. 37%; p = 0.05), when compared to non-cardiologist-prescribed exams. No differences in appropriateness, utility and test result have been detected between elective and urgent exams. Exercise test, echocardiogram and Holter monitoring resulted more often appropriate and useful when prescribed by cardiologists.

CONCLUSIONS

This study confirms that only one third of prescriptions for non-invasive cardiological tests are appropriate. Cardiologist-prescribed exams are more often appropriate, useful and abnormal.

Presence of cardiovascular structural changes in essential hypertensive patients with coronary microvascular disease and effects of long-term treatment

In asymptomatic essential hypertensive patients with angiographically normal coronary arteries and without left ventricular hypertrophy, dipyridamole-induced ischemic-like ST segment depression may be a marker of coronary microvascular disease. In this study we evaluated, first, whether this cardiac abnormality is linked to structural or functional vascular abnormalities, and second, the effect of antihypertensive treatment by 12-month administration of the angiotensin converting enzyme (ACE) inhibitor captopril (50 mg twice a day orally). In essential hypertensives with dipypridamole echocardiography stress test (DET) (DET+, n = 8) and without (DET-, n = 8) ST segment depression greater than 0.1 mV during intravenous dipyridamole infusion (0.84 mg/kg over 10 min), we studied the forearm blood flow (FBF, venous plethysmography, mL/100) modifications induced by intrabrachial acetylcholine (Ach) (0.15, 0.45, 1.5, 4.5, 15 micrograms/100 mL/min x 5 min each), an endothelium-dependent vasodilator, and by sodium nitroprusside (SNP) (1, 2, 4 micrograms/100 mL/min x 5 min each), a smooth muscle cell relaxant compound. Minimal forearm vascular resistances (MFVR), an index of arteriolar structural changes, were also calculated. Both Ach and SNP caused greater vasodilation in DET- as compared to DET+ while MFVRs were lower in DET- compared to DET+. After treatment, both DET+ and DET- patients showed a significant and similar reduction in blood pressure and left ventricular mass index, while vasodilation to acetylcholine and sodium nitroprusside was increased only in the DET+ group. In addition, forearm minimal vascular resistances were significantly reduced only in DET+ patients, who showed disappearance of dipyridamole-induced ischemic-like ST segment depression. In conclusion, these data confirm that essential hypertensive patients with microvascular coronary disease are characterized by the presence of structural changes in the forearm vascular bed. Our results also indicate that both cardiac and forearm vascular abnormalities can be reversed by antihypertensive treatment with an ACE inhibitor.

Low dose atrial natriuretic factor in primary aldosteronism: renal, hemodynamic, and vascular effects

Whether atrial natriuretic factor (ANF) plays a physiological role in primary aldosteronism has yet to be determined. In the present study, the renal, hemodynamic, humoral, and vascular effects of a synthetic (WY-47663) human analogue were studied in five water-loaded (15 ml H2O/kg) patients with adenomatous primary aldosteronism, a salt-sensitive, low renin, volume-expanded syndrome. ANF was infused for 3 hours at a low rate (0.005 micrograms/kg/min), which approximately doubled circulating immunoreactive ANF. Glomerular filtration rate and renal blood flow (inulin and para-aminohippurate clearance) remained stable, but sodium excretion increased significantly suggesting a dissociation between renal hemodynamics and natriuresis as well as a direct inhibitory effect on tubular sodium reabsorption by ANF. Intra-arterial diastolic blood pressure, heart rate, forearm blood flow (plethysmographic method), and arterial plasma norepinephrine did not change, but systolic blood pressure declined and hematocrit rose suggesting plasma volume contraction by ANF. Plasma aldosterone levels were unchanged indicating a loss of ANF-mediated aldosterone inhibition, possibly related to qualitative or quantitative alterations of ANF receptors in tumoral adrenal tissue. Infusion of the analogue into the brachial artery was at a rate of 0.005 micrograms/dl forearm tissue/min x 30 minutes, which also doubled local immunoreactive venous ANF concentrations and vasodilated forearm arterioles. These data suggest a physiological role for ANF in modulating body fluid volume even in human primary aldosteronism.