Hirohisa Horinouchi

Phase II clinical study of photodynamic therapy using mono-l-aspartyl chlorin e6 and diode laser for early superficial squamous cell carcinoma of the lung

Photofrin is the most commonly used photosensitizer for photodynamic therapy (PDT). The major side effect of Photofrin is cutaneous photosensitivity. A second generation photosensitizer, mono-L-aspartyl chlorin e6 (NPe6) has shown anti-tumor efficacy and rapid clearance from skin. Therefore, we conducted a phase II clinical study to investigate the anti-tumor effects and safety of NPe6 in patients with early superficial squamous cell carcinoma of the lung. Enrollment criteria consisted of endoscopically evaluated early stage lung cancer with normal chest X-ray and CT images, no lymph node or distant metastasis. Tumors were located no more peripherally than subsegmental bronchi, the peripheral margin had to visible, and the tumor size had to not more than 2 cm in diameter. The histologic type of the tumor had to squamous cell carcinoma. Laser irradiation (100 J/cm2) using a diode laser was performed at 4 h after administration of NPe6 (40 mg/m2). Among 41 patients with 46 lesions, 40 with 45 lesions were eligible for safety evaluation, and 35 patients with 39 lesions were judged as eligible for efficacy evaluation. No serious adverse drug reactions were observed. Disappearance of skin photosensitivity was recognized within 2 weeks in 28 of 33 patients (84.8%) and in all the other seven patients first tested at 15-18 days. Complete response (CR) was seen in 84.6% of lesions (82.9% of patients). This study demonstrated excellent anti-tumor effects and safety, especially low skin photosensitivity in patients with early stage lung cancer. PDT using the second generation photosensitizer NPe6 and a diode laser will likely become a standard modality of PDT for central type early superficial squamous cell carcinoma of the lung.

Frequency of transmission of human parvovirus B19 infection by fibrin sealant used during thoracic surgery

BACKGROUND Fibrin sealant is used in many kinds of surgical procedures. Although pasteurization is insufficient to remove human parvovirus (HPV) B19 from this plasma-derived product, the frequency of HPV B19 infection transmitted by its use has never been known. METHODS Blood samples of 85 patients more than 20 years of age who had undergone pulmonary resection with fibrin sealant were obtained before and 12, 24, and 48 weeks after surgery. Anti-HPV B19 antibody IgG (HPV B19 IgG) and HPV B19 DNA were detected with these samples. RESULTS In 56 (65.9%) of 85 patients, blood samples obtained before operation were positive for HPV B19 IgG. In these 56 patients, blood samples obtained 12 to 48 weeks after surgery were all negative for HPV B19 DNA by polymerase chain reaction (PCR). In 6 (20.7%) of 29 patients whose blood samples were negative for HPV B19 IgG before surgery, blood samples obtained 12 to 48 weeks after surgery were positive for HPV B19 DNA by PCR and also positive for HPV B19 IgG. In 5 of these 6 patients reticulocyte counts decreased to less than 10 x 10(9)/l 12 to 20 days after surgery. CONCLUSIONS Epidemiologic evidence suggests that more than 20% uninfected persons were subsequently infected with HPV B19 by use of fibrin sealant during surgery.

Hemoglobin-vesicles suspended in recombinant human serum albumin for resuscitation from hemorrhagic shock in anesthetized rats

ObjectiveHemoglobin-vesicle (HbV) has been developed to provide oxygen-carrying ability to plasma expanders. Its ability to restore the systemic condition after hemorrhagic shock was evaluated in anesthetized Wistar rats for 6 hrs after resuscitation. The HbV was suspended in 5 g/dL recombinant human serum albumin (HbV/rHSA) at an Hb concentration of 8.6 g/dL. DesignProspective, randomized, controlled trial. SettingDepartment of Surgery, School of Medicine, Keio University. SubjectsForty male Wistar rats. InterventionsThe rats were anesthetized with 1.5% sevoflurane inhalation throughout the experiment. Polyethylene catheters were introduced through the right jugular vein into the right atrium for infusion and into the right common carotid artery for blood withdrawal and mean arterial pressure monitoring. Measurements and Main ResultsShock was induced by 50% blood withdrawal. The rats showed hypotension (mean arterial pressure = 32 ± 10 mm Hg) and significant metabolic acidosis and hyperventilation. After 15 mins, they received HbV/rHSA, shed autologous blood (SAB), washed homologous red blood cells (wRBC) suspended in rHSA (wRBC/rHSA, [Hb] = 8.6 g/dL), or rHSA alone. The HbV/rHSA group restored mean arterial pressure to 93 ± 8 mm Hg at 1 hr, similar to the SAB group (92 ± 9 mm Hg), which was significantly higher compared with the rHSA (74 ± 9 mm Hg) and wRBC/rHSA (79 ± 8 mm Hg) groups. There was no remarkable difference in the blood gas variables between the resuscitated groups; however, two of eight rats in the rHSA group died before 6 hrs. After 6 hrs, the rHSA group showed significant ischemic changes in the right cerebral hemisphere relating to the ligation of the right carotid artery followed by cannulation, whereas the HbV/rHSA, SAB, and wRBC/rHSA groups showed less changes. ConclusionsHbV suspended in recombinant human serum albumin provides restoration from hemorrhagic shock that is comparable with that using shed autologous blood.

Hemoglobin-Vesicles as Oxygen Carriers: Influence on Phagocytic Activity and Histopathological Changes in Reticuloendothelial System

Hemoglobin-vesicles (HbV) have been developed for use as artificial oxygen carriers (particle diameter, 250 nm) in which a purified Hb solution is encapsulated with a phospholipid bilayer membrane. The influence of HbV on the reticuloendothelial system was studied by carbon clearance measurements and histopathological examination. The HbV suspension ([Hb] = 10 g/dl) was intravenously infused in male Wistar rats at dose rates of 10 and 20 ml/kg, and the phagocytic activity was measured by monitoring the rate of carbon clearance at 8 hours and at 1, 3, 7, and 14 days after infusion. The phagocytic activity transiently decreased one day after infusion by about 40%, but it recovered and was enhanced at 3 days, showing a maximum of about twice the quiescent level at 7 days, and then returned to the normal value at 14 days. The initial transient decreased activity indicates a partly, but not completely, suppressed defensive function of the body. The succeeding increased phagocytic activity corresponds to the increased metabolism of HbV. The histopathological examination with anti-human Hb antibody, hematoxylin/eosin, and oil red O stainings showed that HbV was metabolized within 7 days. Hemosiderin was very slightly confirmed with Berlin blue staining at 3 and 7 days in liver and spleen, though they completely disappeared at 14 days, indicating that the heme metabolism, excretion or recycling of iron proceeded smoothly and iron deposition was minimal. Electron microscopic examination of the spleen and liver tissues clearly demonstrated the particles of HbV with a diameter of about 1/40 of red blood cells in capillaries, and in phagosomes as entrapped in the spleen macrophages and Kupffer cells one day after infusion. The vesicular structure could not be observed at 7 days. Even though the infusion of HbV modified the phagocytic activity for 2 weeks, it does not seem to cause any irreversible damage to the phagocytic organs. These results offer important information for evaluating the safety issues of HbV for clinical use.

Histopathological features and prognostic significance of the micropapillary pattern in lung adenocarcinoma

The micropapillary pattern is characterized by small papillary tufts with no fibrovascular core lying in spaces and has been reported as an aggressive variant of carcinoma in several organs. We investigated the histopathobiological properties of the micropapillary pattern with immunohistochemistry, serial sections, and electron microscopy in lung adenocarcinoma. We further analyzed its clinicopathological character and prognosis. The subjects included 383 adenocarcinoma cases, of which 184 (48%) were micropapillary pattern-positive and 199 (52%) were micropapillary pattern-negative. On histology, micropapillary tufts seemed to float in the alveolar space or spaces encased by connective tissues, whereas serial sections revealed that most tufts had continuity with other tufts and even with the main tumor. Positive staining for the adhesion molecules E-cadherin and β-catenin suggested the preservation of tight adhesion, and electron microscopy showed the existence of intercellular junctions. Negative staining for laminin and loss of basement membrane as determined by electron microscopy suggest a loss of cell–matrix contact. Positive staining for Ki-67 indicates that cells constituting micropapillary tufts retained their proliferation potency. There were no CD34-positive cells in micropapillary tufts, and the loss of the vascular core was confirmed. In micropapillary pattern-positive cases, lymphatic invasion was identified significantly more frequently than in micropapillary pattern-negative cases (P<0.001), even at stageIA (without lymph node metastasis, N=197) (P<0.001). The 5-year and 10-year overall survival rates of the micropapillary pattern-positive stageIA group were 77.6 and 67.6%, respectively, which were significantly less than those of the micropapillary pattern-negative stageIA group (98.1 and 98.1%) (P=0.001). In conclusion, cells constituting the micropapillary pattern are likely to have acquired anchorage-independent growth and a potential for high malignancy.

Haemoglobin-vesicles as artificial oxygen carriers: present situation and future visions

During the long history of development of haemoglobin (Hb)‐based O2 carriers (HBOCs), many side effects of Hb molecules have become apparent. They imply the physiological importance of the cellular structure of red blood cells. Hb‐vesicles (HbV) are artificial O2 carriers that encapsulate concentrated Hb solution with a thin lipid membrane. We have overcome the intrinsic issues of the suspension of HbV as a molecular assembly, such as stability for storage and in blood circulation, blood compatibility and prompt degradation in the reticuloendothelial system. Animal tests clarified the efficacy of HbV as a transfusion alternative and the possibility for other clinical applications. The results of ongoing HbV research make us confident in advancing further development of HbV, with the expectation of its eventual realization.

Evaluation of the capabilities of a hemoglobin vesicle as an artificial oxygen carrier in a rat exchange transfusion model

Encapsulation of hemoglobin within a liposome is one of the strategies in the development of artificial oxygen carriers. It maintains the oxygen transporting properties of hemoglobin and, at the same time, eliminates the side effects of cell free hemoglobin. Hemoglobin vesicles (HbV) are a type of liposome encapsulated hemoglobin. They have a particle size of approximately 250 nm, a hemoglobin concentration of 10 g/ dl, and the oxygen affinity, P50, is regulated to 32 Torr. In this study the authors examined the oxygen transporting capability of HbV in vivo, by performing exchange transfusions in rats. Exchange transfusion (90% of the estimated circulatory volume) with HbV suspended in 5% albumin (containing 160 mEq/L, sodium and 107 mEq/L, chloride) was carried out in male Wistar rats. Mean arterial pressure and heart rate were monitored through the arterial catheter. Arterial blood samples for gas analyses were also obtained from the arterial catheter. Abdominal aortic blood flow was measured by an ultrasonic pulsed Doppler flowmeter as an indicator of cardiac output. The oxygen tension of blood withdrawn from the right atrium was measured as an indicator of mixed venous oxygen tension. These values were employed to calculate oxygen delivery and consumption. Renal cortical and skeletal muscle tissue oxygen tensions were monitored as indicators of tissue perfusion. Five percent albumin and washed rat red blood cells suspended in 5% albumin containing 10 g/dl of hemoglobin, were employed as controls. At the completion of a 90% exchange transfusion, renal cortical and skeletal muscle tissue oxygen tensions, along with oxygen delivery and consumption, were sustained almost equally well with the HbV suspension compared to the washed rat red blood cell suspension, but declined significantly with the albumin suspension. The results indicate that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells.

Review of Hemoglobin-Vesicles as Artificial Oxygen Carriers

Blood transfusion systems have greatly benefited human health and welfare. Nevertheless, some problems remain: infection, blood type mismatching, immunological response, short shelf life, and screening test costs. Blood substitutes have been under development for decades to overcome such problems. Plasma component substitutes have already been established: plasma expanders, electrolytes, and recombinant coagulant factors. Herein, we focus on the development of red blood cell (RBC) substitutes. Side effects hindered early development of cell-free hemoglobin (Hb)-based oxygen carriers (HBOCs) and underscored the physiological importance of the cellular structure of RBCs. Well-designed artificial oxygen carriers that meet requisite criteria are expected to be realized eventually. Encapsulation of Hb is one idea to shield the toxicities of molecular Hbs. However, intrinsic issues of encapsulated Hbs must be resolved: difficulties related to regulating the molecular assembly, and management of its physicochemical and biochemical properties. Hb-vesicles (HbV) are a cellular type of HBOC that overcome these issues. The in vivo safety and efficacy of HbV have been studied extensively. The results illustrate the potential of HbV as a transfusion alternative and promise its use for other clinical applications that remain unattainable using RBC transfusion.

Hemoglobin vesicles, polyethylene glycol (PEG)ylated liposomes developed as a red blood cell substitute, do not induce the accelerated blood clearance phenomenon in mice.

The hemoglobin vesicle (HbV) is an artificial oxygen carrier encapsulating a concentrated hemoglobin solution in a liposome of which the surface is covered with polyethylene glycol (PEG). It was recently reported that repeated injections of PEGylated liposomes induce the accelerated blood clearance (ABC) phenomenon, in which serum anti-PEG IgM plays an essential role. To examine this issue, we investigated whether HbV induces the ABC phenomenon in mice at a dose of 0.1 mg Hb/kg, a dose that is generally known to induce the ABC phenomenon, or at 1400 mg Hb/kg, which is proposed for clinical use. At 7 days after the first injection of nonlabeled HbV (0.1 mg Hb/kg), the mice received HbV in which the Hb had been labeled with 125I. After a second injection, HbV was rapidly cleared from the circulation, and uptake clearances in liver and spleen were significantly increased. In contrast, at a dose of 1400 mg Hb/kg, the pharmacokinetics of HbV was negligibly affected by repeated injection. It is interesting to note that IgM against HbV was produced 7 days postinjection at both of the above doses, and their recognition site was determined to be 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine-N-PEG in HbV. These results suggest that a clinical dose of HbV does not induce the ABC phenomenon, and that suppression of ABC phenomenon is caused by the saturation of phagocytic processing by the mononuclear phagocyte system. Thus, we conclude that induction of the ABC phenomenon would not be an issue in the dose regimen used in clinical settings.

Pretreatment of serum containing hemoglobin vesicles (oxygen carriers) to prevent their interference in laboratory tests

Abstract Hemoglobin vesicles (HbV, diameter: 251±81 nm) are artificial oxygen (O2) carriers encapsulating concentrated hemoglobin (Hb) solution with phospholipid bilayer membrane, and their O2 transporting ability in vivo has been extensively studied. It is important to clarify the interference of the HbV suspension in clinical laboratory tests performed on serum and to establish a pretreatment method to avoid such an interference. The HbV suspension, acellular Hb solution ([Hb] = 10 g/dl) or saline, was mixed with a pooled human serum at various ratios up to 50 vol% ([Hb] = 5 g/dl), and the magnitude of the interference effect of HbV and Hb on 30 analytes was studied. The mixture of the HbV suspension and serum was ultracentrifuged (50000 g, 20 min) to remove the HbV particles as precipitate, and the supernatant was analyzed and compared with the saline control group. The HbV particles were also removed by centrifugation (2700 g, 30 min) in the presence of dextran (Mw 200 kDa). The HbV suspension showed considerable interference effects in most analytes. The majority of these effects was more serious than those of the acellular Hb solution. These findings are thought to be due to the light absorption of Hb in HbV and/or the light scattering generated in the suspension that interferes with the colorimetric and turbidimetric measurements. The components of HbV may also interfere with the chemical reactions of the studied assays. However, removal of the HbV from the supernatant diminished the interference in most of the assays: this is an advantage of HbV in comparison with acellular chemically modified Hb solutions.