Minimization of temperature for laser cooling of Yb-ion-doped crystals.

In this paper, quantum mechanical calculations of cooling characteristics for the Yb:  YLF system with use of the vibronic model of laser cooling are presented. Dynamics of the laser cooling process for the seven-level system of an Yb ion is described by the density-matrix formalism. Dependences of the cooling characteristics on the pump intensity are obtained for various temperatures and absorption coefficients of impurity ions.

Effect of transfusion on cerebral oxygenation, flow velocity in a patient with sickle cell anemia and Moyamoya disease: a case report.

Vascular occlusive diseases affect brain blood flow, brain metabolism and are associated with arterial ischemic stroke. This study was designed to measure the brain blood flow velocity, brain oxygenation, hemoglobin concentrations, hematocrit, and cell free hemoglobin at pre- and post-exchange red cell transfusion in an 18 year old male patient with sickle cell disease and moyamoya syndrome (MMS). Exchange transfusion increased cerebral oxygen saturation 12%, total hemoglobin concentration 2%, hemoglobin AA 80%, and reduced sickle (SS) hemoglobin 12%, arterializations 33%, and cell free hemoglobin 33%.

Plasma levels of TNF-alpha in sickle cell patients receiving hydroxyurea.

Hydroxyurea (HU), a chemotherapeutic agent, used increasingly in the treatment of sickle cell disease (SCD) stimulates the release of a tumor necrosis factor (TNF-alpha) from human macrophages in vitro and the concentration of TNF-alpha is greater than normal in subjects affected by SCD. It is widely accepted that HU may inhibit vaso-occlusive crisis (VOC) by stimulating the production of fetal hemoglobin (HbF) and nitric oxide (NO) in SCD; however, the beneficial effects of HU in vivo may be counteracted by the release of TNF-alpha and, in turn, the expression of a vascular cell adhesion molecule (VCAM-1) on leukocytes. Previous studies have shown that the severity of SCD increases with the leukocyte count.

Arterialization of venous blood for differentiation of sickle cell subjects in vaso-occlusive crisis.

These studies were designed as two experiments. Experiment 1 was performed to validate the hypothesis that oxygen saturation of the venous blood may be a marker for vaso-occlusive crisis (VOC) in sickle cell patients undergoing hydroxyurea (HU) treatments. Experiment 2 was performed to test the hypothesis that an acute increase in the blood nitric oxide (NO) concentration by administering HU modulates the perception of pain in sickle cell subjects in VOC.

Long-term outcomes in patients with sickle cell disease and frequent vaso-occlusive crises.

Background: The frequency of vaso-occlusive crises correlates with mortality in patients with sickle cell disease (SCD). We examined the degree to which a high number of hospitalization days for these events affected survival.

Patients And Methods: We reviewed data for 58 adult patients with SCD (mean age, 29.

Nitric oxide and cyclic GMP levels in sickle cell patients receiving hydroxyurea.

Recent studies suggest that nitric oxide (NO) may partly be responsible for the beneficial effect of hydroxyurea (HU) in sickle cell disease (SCD) patients. NO stimulates cyclic guanosine monophosphate (cGMP) production, which mediates vasodilatation. We investigated the association between NO, cGMP and fetal haemoglobin (HbF) levels after HU administration.

Arterialization of peripheral venous blood in sickle cell disease.

Arterialization of the venous blood is thought to be indicative of cutaneous shunting, and occurs in patients with sickle cell disease (SCD) during vaso-occlusive crisis (VOC). We performed the present study to quantify the amount of shunting that occurs in sickle cell patients presenting at the Howard University Sickle Cell Center, Washington, D.C.

Nitric Oxide Metabolites in Sickle Cell Anemia Patients after Oral Administration of Hydroxyurea; Hemoglobinopathy.

The mechanism of action of hydroxyurea (HU) in decreasing the frequency of pain crisis in sickle cell disease (SCD) has not been fully elucidated. In vitro and in vivo studies suggest that nitric oxide (NO), a potent vasodilator, may partly be responsible for the beneficial effect of HU. This study was designed to determine the effect of oral administration of HU on plasma levels of NO metabolites (NO(x) ) in sickle cell patients (SCP).

Homocysteine in sickle cell disease: relationship to stroke.

Purpose: The risk factors and pathophysiology of stroke and other serious complications of sickle cell disease (SCD) are poorly defined. Hyperhomocysteinemia has recently been identified as a risk factor for stroke and other vascular diseases in the general population, however its role in SCD has not been investigated.

Patients And Methods: We measured serum homocysteine and red cell folate levels in 100 patients with SCD, including 16 patients with stroke.

Cancer incidence rate and mortality rate in sickle cell disease patients at Howard University Hospital: 1986-1995.

The incidence of cancer in patients with sickle cell disease (SCD) is not known. The 10-year follow-up data on 696 patients with SCD was analyzed at our institution in order to determine the cancer incidence and cancer mortality rates. The age range was 18 to 79 years, with a mean age of 28.

The impact of health insurance on an African-American population with colorectal cancer.

This study evaluates the impact of health insurance as a substitute for social class on tumor location, presentation, stage, grade, and age-adjusted survival in an African-American population. Patients were stratified by insurance into two groups: group 1 (private insurance and Medicare parts A & B) and group 2 (Medicaid, Medical Charity, self-pay, uninsured, or unemployed). A total of 212 patients were evaluated.

Enhancement of pain control with ketorolac tromethamine in patients with sickle cell vaso-occlusive crisis.

Twenty one patients with sickle cell disease admitted to the hospital with the pain of vaso-occlusive crisis (VOC) were treated by continuous IV infusion of ketorolac or normal saline for up to 5 days. All patients received supplemental IM injections of meperidine, 100 mg, as necessary, but not more frequently than every 3 hr. Over the 5 days the ketorolac treated patients (KT) required 33% less meperidine than did the placebo treated patients (PL), P = 0.

Erythropoietin: a review.

The fact that a plasma factor was responsible for the stimulation of red cell production has been known for more than 35 years. However, it is only recently that the gene responsible for its production and its molecular structure has been identified. Furthermore, recombinant human erythropoietin is now available for clinical use.

Preventing falls in the elderly. A practical approach to a common problem.

Considerable morbidity and mortality occur among the elderly every year in the United States as a result of falls. Assessing the risk of falling with use of thorough history taking, physical examination, and special tests of balance and gait allows physicians to make specific safety recommendations.

The impact of pulmonary infections on the survival of lung cancer patients.

To determine the impact of pulmonary infections on survival in patients with lung cancer, a retrospective review of the records of 121 such patients treated at Howard University Hospital in Washington, DC, was done. There were 77 men and 44 women; 118 were black. The mean age was 63.

Patient-controlled analgesia in patients with sickle cell vaso-occlusive crisis.

Pain control using intramuscular analgesia is often unsatisfactory in sickle cell patients. In a pilot study, 15 patients with sickle cell anemia (SS) and one patient with SB thalassemia in vaso-occlusive crisis were treated with the Patient-Controlled Analgesia (PCA) technique using a Pharmacia Deltec Programmable pump (CADD PCA). Age range was 19-50 years (median = 27); there were nine females and seven males.

Acute promyelocytic leukemia following treatment of non-Hodgkin's lymphoma.

A case of acute promyelocytic leukemia (APL) 3 years following the treatment of diffuse mixed non-Hodgkin's lymphoma (NHL) is presented. This is the second time APL after NHL has been reported in the literature.