Laser-induced effects in different biological samples

Experiments were carried out on cancerous HeLa cells and blood serum using a double integrating sphere and a He-Ne laser to investigate the optical properties and cellular effects due to photodynamic therapy (PDT). In the first experiment, HeLa cells were exposed to Photofrin at concentrations of 0, 10, 20, 30, 50 and 112.4 μg/ml at an irradiance of 0.2 W/cm² using diode laser light. Using a confocal microscope, cell debris and morphological changes in HeLa cells were recorded at different Photofrin concentrations. The results showed cell debris in HeLa cells at the highest concentration of Photofrin. In a second experiment, photobleaching was observed in HeLa cells in the presence of various concentrations of 5-aminolaevulinic acid ranging from 0–50 μg/ml. There was progressive degradation of the 635 nm peak during continuous laser irradiation at an irradiance of 0.2 W/cm². We conclude that cells demonstrating high initial fluorescence undergo bleaching at a faster rate than those with lower fluorescence. Finally in a third experiment, cancerous and noncancerous blood serum was irradiated at an irradiance of 0.1 W/cm² using a He-Ne laser in conjunction with a double integrating sphere system. Forward and back scattering of normal and malignant serum showed an exponential decrease in fluorescence amplitude. The results indicate that there is notable amplitude difference between malignant and normal blood serum with malignant blood serum showing decreased scattering. These results have important implications for photodiagnosis and photodynamic therapy.     

Evaluation of perfusion modes on vital organ recovery and thyroid hormone homeostasis in pediatric patients undergoing cardiopulmonary bypass

The objectives of this study were: (i) to evaluate the effects of perfusion modes (pulsatile vs. nonpulsatile) on vital organs recovery and (ii) to investigate the influences of two different perfusion modes on the homeostasis of thyroid hormones in pediatric patients undergoing cardiopulmonary bypass (CPB) procedures. Two hundred and eighty‐nine consecutive pediatric patients undergoing open heart surgery for repair of congenital heart disease were prospectively entered into the study and were randomly assigned to two groups: the pulsatile perfusion group (Group P, n = 208) and the nonpulsatile perfusion group (Group NP, n = 81). All patients received identical surgical, perfusional, and postoperative care. Study parameters included total drainage, mean urine output in the intensive care unit (ICU), intubation time, duration of ICU and hospital stay, the need for inotropic support, pre‐ and postoperative enzyme levels (ALT [alanine aminotransaminase] and AST [aspartate aminotransaminase]), c‐reactive protein, lactate, albumin, blood count (leukocytes, hematocrit, platelets), creatinine levels, and thyroid hormones (thyroid stimulating hormone [TSH], FT₃[free triiodothyronine], FT₄[free thyroxine]). All patients survived the perioperative and postoperative periods. There were no statistically significant differences in either preoperative or operative parameters between the two groups. Group P, compared to Group NP, required significantly less inotropic support, had a shorter intubation period, higher urine output in ICU, and shorter duration of ICU and hospital stay. Lower lactate levels and higher albumin levels were observed in Group P and there were no significant differences in creatinine, enzyme levels, blood counts, or drainage amounts between two groups. TSH, Total T₃, Total T₄, and FT₃, FT₄ levels were markedly reduced versus their preoperative values in both groups. FT₃ and FT₄ levels were reduced significantly further in the nonpulsatile group both during CPB and at 72 h postoperation. The results of this study confirm our opinion that pulsatile perfusion leads to better vital organ recovery and clinical outcomes in the early postoperative period as compared to nonpulsatile perfusion in pediatric patients undergoing CPB cardiac surgery. The plasma concentrations of thyroid hormones are dramatically reduced during and after CPB, but pulsatile perfusion seems to have a protective effect of thyroid hormone homeostasis compared to nonpulsatile perfusion.     

Loss of myostatin (GDF8) function increases osteogenic differentiation of bone marrow-derived mesenchymal stem cells but the osteogenic effect is ablated with unloading

Myostatin (GDF8) is a negative regulator of skeletal muscle growth and mice lacking myostatin show a significant increase in muscle mass and bone density compared to normal mice. In order to further define the role of myostatin in regulating bone mass we sought to determine if loss of myostatin function significantly altered the potential for osteogenic differentiation in bone marrow-derived mesenchymal stem cells in vitro and in vivo. We first examined expression of the myostatin receptor, the type IIB activin receptor (AcvrIIB), in bone marrow-derived mesenchymal stem cells (BMSCs) isolated from mouse long bones. This receptor was found to be expressed at high levels in BMSCs, and we were also able to detect AcvrIIB protein in BMSCs in situ using immunofluorescence. BMSCs isolated from myostatin-deficient mice showed increased osteogenic differentiation compared to wild-type mice; however, treatment of BMSCs from myostatin-deficient mice with recombinant myostatin did not attenuate the osteogenic differentiation of these cells. Loading of BMSCs in vitro increased the expression of osteogenic factors such as BMP-2 and IGF-1, but treatment of BMSCs with recombinant myostatin was found to decrease the expression of these factors. We investigated the effects of myostatin loss-of-function on the differentiation of BMSCs in vivo using hindlimb unloading (7-day tail suspension). Unloading caused a greater increase in marrow adipocyte number, and a greater decrease in osteoblast number, in myostatin-deficient mice than in normal mice. These data suggest that the increased osteogenic differentiation of BMSCs from mice lacking myostatin is load-dependent, and that myostatin may alter the mechanosensitivity of BMSCs by suppressing the expression of osteogenic factors during mechanical stimulation. Furthermore, although myostatin deficiency increases muscle mass and bone strength, it does not prevent muscle and bone catabolism with unloading.     

Elderly depressed patients: What are their views on treatment options?

The aim of this study was to explore attitudes of elderly patients with depression receiving secondary psychiatric care towards different types of treatment for depression. One hundred patients, recruited from a large teaching hospital in Birmingham, were subjected to structured interviews at which their attitudes towards the effectiveness, likelihood of causing side-effects and acceptability of anti-depressant medication, ECT and psychotherapy were measured on a five-point Likert scale. Psychotherapy was considered both effective and acceptable by our patients although it is not widely available across the UK. Anti-depressants were also considered to be effective and acceptable although likely to cause side-effects. However, our patients did not think highly of ECT, either in its effectiveness or acceptability.     

Endoscopic Diagnosis of a Clinically Silent Aortoesophageal Fistula: Case Report and Review of the Literature

We report a rare case of a secondary aortoesophageal fistula discovered incidentally during elective upper endoscopy. The patient had previously undergone repair of a descending thoracic aortic aneurysm with a Dacron interposition graft. Esophagoscopy 2 months after the aneurysm repair demonstrated a large mid-esophageal erosion with visualization of the aortic graft at the base. The aortoesophageal fistula had been clinically silent to this point. During preparation for surgery the patient developed large-volume esophageal hemorrhage and died following attempted endovascular repair of the fistula. A review of the literature on the diagnosis and surgical management of aortoesophageal fistula is presented.Presented at the 30th Annual Meeting of the Military Society for Vascular Surgery, Bethesda, MD, December 5, 2002.     

The effect HBOC-201 and sodium nitrite resuscitation after uncontrolled haemorrhagic shock in swine

BackgroundDevelopment of Haemoglobin-based oxygen carriers (HBOCs) as blood substitutes has reached an impasse due to clinically adverse outcomes attributed to vasoconstriction secondary to nitric oxide (NO) scavenging. Studies suggest haemoglobin exhibits nitrite reductase activity that generates NO and N₂O₃; harnessing this property may offset NO scavenging. Therefore, the effects of concomitantly infusing sodium nitrite (NaNO₂) with HBOC-201 were investigated.MethodsSwine underwent uncontrolled liver haemorrhage before receiving up to three 10 min 10 ml/kg infusions of HBOC-201 (HBOC) with or without concurrent NaNO₂ (5.4 μmol/kg [LD NaNO₂] or 10.8 μmol/kg [HD NaNO₂]) or 6% Hetastarch (HEX) with or without HD NaNO₂ during “prehospital” resuscitation (15, 30 and 45 min after injury). Definitive surgical care occurred at 75 min; anaesthetic recovery at 120 min. Animals were euthanised at 72 h.ResultsNaNO₂ temporarily reduced systemic and pulmonary blood pressure increases from HBOC in a dose-dependent fashion. There was no significant effect between groups in indices of tissue oxygenation or survival. Adverse clinical signs requiring humane euthanasia occurred with highest frequency after HBOC + HD NaNO₂ (3 of 4 pigs) and HBOC + LD NaNO₂ (2 of 4 pigs). Gross evidence of pulmonary congestion was observed in 5 of 8 swine receiving a HBOC and NaNO₂ combination compared to 1 of 16 swine receiving HBOC alone, HEX alone, or HEX + NaNO₂. Gross lesions correlated with histological evidence of pulmonary oedema and congestion, and in 2 of 4 HBOC + HD NaNO₂ pigs, pulmonary fibrin thrombi also were found. No other pig had similar evidence of thrombi. Asymmetric pre-resuscitation cardiac index was a potential confounder.ConclusionsA significant interaction between NaNO₂ and HBOC-201 ameliorated HBOC-201 vasoconstrictive effects, consistent with HBOC possessing a nitrite reductase activity that generates vasodilator NO equivalents. Results were relatively equivalent in survival and markers of tissue oxygenation. The highest dose of NaNO₂ was the most effective in reducing HBOC-associated pulmonary and systemic vasoactivity but also with the highest incidence of adverse events. In this model, the transient nature of NaNO₂ in off-setting HBOC-201 vasoconstriction makes it less clinically promising than anticipated and the combination of NaNO₂ and HBOC appear to increase the risk of pulmonary complications in a dose-dependent fashion independently of haemodilutional effects on haemostatic components.     

Lack of effect of intrarectal lidocaine for pain control during transrectal prostate biopsy: a randomized prospective study

INTRODUCTION AND OBJECTIVES: Transrectal ultrasound guided biopsy is an essential part in the diagnosis of prostate cancer. Although this procedure is well tolerated by most patients, sometimes it can result in some uneasiness. In this randomised double-blind placebo controlled study, we evaluated the effectiveness of intrarectal lidocaine during TRUS guided biopsy. MATERIALS AND METHODS: 100 consecutive eligible patients who had elevated total prostate specific antigen (tPSA) and/or abnormal digital rectal examination (DRE) were included into this study. Patients were randomised into two groups. Group I received 20 cc of 2% intrarectal lidocaine 20 minutes before transrectal ultrasound guided biopsy and Group II received same amount of serum physiologic. Pain was assessed using a 10 point modified visual analog scale. RESULTS: Mean patient age was 65.5+/-2.5 and 64.5+/-11.5 years, mean tPSA was 12.3+/-3.6 and 11.3+/-1.7 ng/ml, mean biopsy duration was 6.8+/-2.5 and 6.6+/-2.2 minutes, mean pain score during transrectal ultrasound guided biopsy was 4.8+/-2.2 and 4.4+/-2.1 in Groups I and II, respectively. No statistically significant difference was observed with respect to age, tPSA, mean biopsy duration and pain score between these groups. There was only one patient who could not tolerate the procedure at all, and he was paradoxically in the lidocaine group. CONCLUSION: The use of intrarectal lidocaine is not superior to placebo during transrectal prostate biopsy for pain control.     

Mammary tuberculosis: analysis of thirty-eight patients

Thirty-eight patients with mammary gland tuberculosis were evaluated over a 5-year period presenting to the surgical unit of our institution. Unilateral involvement of the breast in a woman presenting at an average age of 29 years was the commonest observation. A lump in the breast with or without discharging sinuses was the most common clinical presentation. Ten (26%) of these patients had breast pain with or without increased breast nodularity. Axillary lymph nodal involvement was evident in 14 (36%) of our patients. Only five patients had associated pulmonary tuberculosis, the rest having an isolated involvement of the breast. Fine-needle aspiration cytology was the most reliable diagnostic modality. Medical therapy with antitubercular drugs ranging from 6 to 9 months was the mainstay of treatment. Surgical intervention was reserved for selected refractory cases.     

HLA class II antigen presentation by prostate cancer cells

Prostate cancer is the second most commonly diagnosed cancer in men. Recent evidence suggests that reduced expression of target protein antigens and human leukocyte antigen (HLA) molecules is the predominant immune escape mechanism of malignant prostate tumor cells. The purpose of this study was to investigate the prospect of antigen specific immunotherapy against prostate cancer via the HLA class II pathway of immune recognition. Here, we show for the first time that prostate cancer cells express HLA class II proteins that are recognized by CD4+ T cells. Prostate tumor cells transduced with class II molecules efficiently presented tumor-associated antigens/peptides to CD4+ T cells. This data suggests that malignant prostate tumors can be targeted via the HLA class II pathway, and that class II-positive tumors could be employed for direct antigen presentation, and CD4+ T-cell mediated tumor immunotherapy.Prostate Cancer and Prostatic Diseases (2008) 11, 334-341; doi:10.1038/sj.pcan.4501021; published online 16 October 2007.