Endotheliopathy of liver sinusoidal endothelial cells in liver disease

Liver is the largest solid organ in the abdominal cavity, with sinusoid occupying about half of its volume. Under liver disease, hemodynamics in the liver tissue dynamically change, resulting in injury to liver sinusoidal endothelial cells (LSECs). We discuss the injury of LSECs in liver diseases in this article. Generally, in noninflamed tissues, vascular endothelial cells maintain quiescence of circulating leukocytes, and unnecessary blood clotting is inhibited by multiple antithrombotic factors produced by the endothelial cells. In the setting of inflammation, injured endothelial cells lose these functions, defined as inflammatory endotheliopathy. In chronic hepatitis C, inflammatory endotheliopathy in LSECs contributes to platelet accumulation in the liver tissue, and the improvement of thrombocytopenia by splenectomy is attenuated in cases with severe hepatic inflammation. In COVID-19, LSEC endotheliopathy induced by interleukin (IL)-6 trans-signaling promotes neutrophil accumulation and platelet microthrombosis in the liver sinusoids, resulting in liver injury. IL-6 trans-signaling promotes the expression of intercellular adhesion molecule-1, chemokine (C-X-C motif) ligand (CXCL1), and CXCL2, which are the neutrophil chemotactic mediators, and P-selectin, E-selectin, and von Willebrand factor, which are involved in platelet adhesion to endothelial cells, in LSECs. Restoring LSECs function is important for ameliorating liver injury. Prevention of endotheliopathy is a potential therapeutic strategy in liver disease.     

Accumulation of L-[2-(F-18)]fluorophenylalanine in peri-infarct area in a patient with acute cerebral infarction

We studied the brain uptake of amino acid in a patient with acute cerebral infarction with L-[2-(F-18)] fluorophenylalanine and positron emission tomography. The increased accumulation of the ligand was specifically found in the peri-infarct area where oxygen metabolism was still maintained but decreased later in the 72-day follow-up period. The kinetic analysis revealed that increased accumulation was not due to increased transport from the blood to the brain but to delayed washout from the brain to the blood. Although the mechanism is still unknown, abnormally high accumulation of L-[F-18]fluorophenylalanine may predict delayed neuronal changes after ischemic insults of the brain.     

Removal of strontium by the chelating agent acetylamino propylidene diphosphonic acid in rats

Studies of the effects of the chelating agent, calcium acetylamino propylidene diphosphonic acid (Ca-APDA), on the removal of radioactive strontium with two administration modalities were carried out in rats. The parenteral (intraperitoneal) administration of 150, 300, or 600 mg kg(-1) Ca-APDA was carried out for 3 d, 10 min after exposure of the animals to the strontium injection. On the first day post-treatment, the retention of strontium in the whole body decreased to 90.1%, 83.9%, and 35.1% that of the control level, respectively. The strontium deposited in femur of 600 mg kg(-1) Ca-APDA group was lowered to 28.4% of the control value. A single oral dose of 600 mg kg(-1) Ca-APDA administered simultaneously with, or 10 min after, oral administration of strontium, radionuclide retention in the whole body was reduced after 1 d to 42.9% and 31.9% of the control, respectively; meanwhile the strontium deposited in the femur was reduced to 16.9% and 29.3% of the control. In conclusion, the results indicate the efficacy of the new agent, Ca-APDA, to remove radioactive strontium from the body, or to inhibit the strontium intestinal absorption, in radio-strontium contaminated individuals.     

Effect of rotational alignment on patellar tracking in total knee arthroplasty

Forty-four consecutive patients (65 knees) who underwent identical condylar type total knee arthroplasty were evaluated retrospectively. In 22 of the patients (32 knees), the femoral component was set parallel to the posterior condylar axis (neutrally aligned group). In the remaining 22 patients (33 knees), it was set in an external rotation position of 3 degrees to 5 degrees relative to the axis (externally aligned group). Of the total knee arthroplasties in the neutrally aligned group, 34% required lateral release, compared with only 6% in the externally aligned group; patellar tracking in the externally aligned group was significantly better than that in the neutrally aligned group. Postoperative measurements performed using computed tomography scans showed that the mean angle between the prosthetic posterior condylar axis and the transepicondylar axis was 7.9 degrees in the neutrally aligned group and 3.2 degrees in the externally aligned group. The external rotation setting of the femoral component diminished the need for lateral retinacular release and may decrease the rate of patellofemoral complications that occur after total knee arthroplasty.     

Major organ function under mechanical support: comparative studies of pulsatile and nonpulsatile circulation

We examined a major organ function during 3 h biventricular assisted circulation after acute myocardial infarction model in the pig. In left ventricular circulation, the outflow cannula was placed in the ascending aorta and an inflow cannula through the mitral valve in the left ventricle. A pump (pulsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nikkiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmonary artery and an inflow cannula in the right ventricle. The right ventricular circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in the kidney, white matter and gray mater in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flow; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In the pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved rather than in the nonpulsatile assisted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and carotid arterial flow did not show significant differences between the groups. The results of our study indicated that pulsatile circulation produced superior circulation in the kidney and liver, and microcirculation on the cell level was superior as well in early treatment of acute heart failure.     

Association of head trauma with cervical spine injury, spinal cord injury, or both

BACKGROUND: Links between cervical spine and/or spinal cord injuries and head trauma have not been reported in detail. METHODS: 188 patients with cervical spine and/or spinal cord injury were divided into two groups, i.e., with upper cervical and mid-lower cervical injury, and compared for head injury. RESULTS: Associated head trauma was investigated in 188 patients with cervical spine and/or spinal cord injuries; 35% had moderate or severe injuries. Brain damage was more frequently observed in patients with upper cervical injury than in those with mid to lower cervical injury. Those patients with upper cervical injury appeared to have an elevated risk of suffering skull base fractures, traumatic subarachnoid hemorrhage, and contusional hemotoma. CONCLUSIONS: Approximately one third of patients with cervical spine and/or spinal cord injuries had moderate or severe head injuries. Brain damage was more frequently associated with upper cervical injury. Those patients with upper cervical injury are at greater risk of suffering from skull base fractures and severe intracranial hematomas than those with mid to lower cervical injury.     

Endoscopic lithotripsy with the holmium:YAG laser

BACKGROUND AND OBJECTIVE: The holmium:YAG (Ho:YAG) laser can be used not only for soft tissue but also for hard tissue such as urinary calculi. The objective of this study was to assess the usefulness of the Ho:YAG laser for endoscopic lithotripsy in patients with urinary tract stone. STUDY DESIGN/MATERIASL AND METHODS: Of 102 procedures performed among 96 patients, 88 were transurethral ureterolithotripsy (TUL), seven were percutaneous nephrolithotripsy, and seven were transurethral cystolithotripsy. Six patients had bilateral stones. The fragments were reduced as much as possible with the Ho:YAG laser. RESULTS: The efficacy rate of the 102 lithotripsy procedures was 93%. With respect to the effect of TUL, the efficacy rates of 40 procedures for the proximal ureter, 18 procedures for the midureter, and 30 procedures for the distal ureter were 85%, 94%, and 100%, respectively. CONCLUSION: The Ho:YAG laser produced a sufficiently strong lithotripsy force on all stones. The results of this study indicate that lithotripsy of urinary tract stones with the Ho:YAG laser can achieve a clinical outcome equivalent to or exceeding that of pulsed dye laser lithotripsy. The Ho:YAG laser is a multipurpose laser and thus is a cost effective and very useful means for endoscopic lithotripsy of urinary tract stones.