Morphological comparison and functional reconstitution of rat hepatic parenchymal cells on various matrices

Four types of materials, type I collagen coat (Coat), acid-soluble type I collagen gel (Hardgel), pepsin-treated acid-soluble type I collagen gel (Softgel), and an extract of extracellular matrix of the murine Engelbreth-Holm-Swarm sarcoma (Matrigel), were used as matrices to culture rat hepatic parenchymal cells, and their morphological changes and adhesion were compared to the matrices by electron microscopic observations. Hepatic parenchymal cells cultured on Coat and Hardgel were extended and flattened, whereas cells cultured on Softgel and Matrigel assembled and formed aggregates. Such aggregates consisted of several hepatic parenchymal cells, with a recognizable bile duct-like alveolus on the inside. Morphologically, the aggregates were more spherical on Matrigel and oval shaped on Softgel. Microvilli of the cell surface were parallel to the matrix on Matrigel, but invaded into the gel on Softgel. Subsequently, investigation into how these morphological features affected the liver-specific functions, including secretion of albumin and induction of P450 by 3-methylcholanthrene, demonstrated that a high level of liver function was maintained in a long-term culture in hepatic parenchymal cells on Softgel. These results suggest that hepatic parenchymal cell interactions were stronger with Softgel than with Matrigel, and that Softgel appears to closely mimic the in vivo environment.     

MATERNAL HYPERTHYROIDISM AND CONGENITAL MALFORMATION IN THE OFFSPRING

Six hundred and forty-three neonates from mothers with Graves' disease were examined for major malformations of external organs to compare the influence of maternal hyperthyroidism vs. ingestion of methimazole (MMI) during the first trimester on the incidence of congenital malformations. The subjects were divided into four groups according to maternal therapy and thyroid status during the first trimester as follows: (1) infants whose mothers did not receive MMI and were hyperthyroid (Group 1), (2) infants whose mothers did not receive MMI and were euthyroid (Group 2), (3) infants whose mothers received MMI and were hyperthyroid (Group 3) and (4) infants whose mothers received MMI and were euthyroid (Group 4). The prevalence of malformed infants in these four groups was 6.0% (three of 50), 0.3% (one of 350), 1.7% (two of 117) and 0.0% (none of 126), respectively. The incidence in Group 1 was significantly higher than that in Group 2 (P less than 0.01). There was no discernible dose dependency of MMI on the occurrence of malformations. These findings suggest that maternal uncontrolled hyperthyroidism may cause congenital malformations and that the beneficial role of MMI treatment outweighs its teratogenic effect, if any.     

Prognosis and pathological characteristics of five children with non-Shiga toxin-mediated hemolytic uremic syndrome

BACKGROUND: The three major signs of hemolytic uremic syndrome (HUS) are hemolytic anemia, thrombopenia and acute renal failure. HUS is classified into Shiga toxin-mediated HUS (Stx-HUS) and non-Shiga toxin-mediated HUS (nStx-HUS). The prognosis of nStx-HUS is reported to be less favorable than that of Stx-HUS. Although the association between the prognosis and pathological characteristics of HUS have been reported such that the prognosis was considered to be poor for thrombotic microangiopathy (TMA) with predominant arterial involvement (arterial TMA), good for TMA with predominant glomerular involvement (glomerular TMA) and dependent on the extent of necrosis in cases of renal cortical necrosis, it is not yet clear whether pathological findings are also related to the renal prognosis of nStx-HUS cases. Therefore the purpose of the present paper was to analyze renal biopsy findings and prognosis for five children with nStx-HUS. METHODS: Clinical records of five cases of nStx-HUS among 74 cases of diagnosed HUS were reviewed, and information and data were summarized. RESULTS: Histological examination of the kidney led to the diagnosis of arterial TMA in three cases, and glomerular TMA and severe renal cortical necrosis in one case each. Analysis of the relationship between renal histological findings and the prognosis found that three patients with arterial TMA and one patient with severe renal cortical necrosis later developed end-stage renal failure while one patient with glomerular TMA has continued to show normal renal function. CONCLUSIONS: These findings indicate that pathological findings are closely related to the prognosis in cases of nStx-HUS.     

A Biodegradable Poly-l-lactic Acid Coronary Stent in the Porcine Coronary Artery

Although biocompatibility of biodegradable stents is controversial, stents made of high molecular weight poly- l -lactic acid (PLLA) are thought to be the most promising. We investigated the biocompatibility of PLLA stents histologically and angiographically in porcine coronary arteries. The Igaki-Tamai stent is made of PLLA monofilaments (molecular mass 183 kD) with a zigzag helical coil design. Fourteen PLLA stents in 6 pigs and 9 Palmaz-Schatz half stents in 9 pigs were implanted in 15 normocholesterolemic pigs. Stents were mounted on a delivery catheter, and were implanted percutaneously into coronary arteries. Coronary angiography was performed before and immediately after stenting, at 2 and 6 weeks in five PLLA pigs and nine Palmaz-Schatz pigs. Histological studies were performed in PLLA pigs: 2 pigs at 2 weeks, 3 pigs at 6 weeks, and 1 pig at 16 weeks with hematoxylin-eosin and elastica van Giesons stains. All PLLA stents were successfully delivered. No stent thrombosis was detected in either group. There were no significant differences in minimal lumen diameter (MLD) or percent diameter stenosis between the PLLA and Palmaz-Schatz stent groups immediately after implantation, or at 2 or 6 weeks after implantation. Histological studies at 2, 6, and 16 weeks revealed no inflammation and minimal neointimal coverage on the PLLA stent struts. The PLLA stent maintained its structure for up to 16 weeks. These results suggest sufficient biocompatibility and strength of PLLA biodegradable stents in porcine coronary arteries. Clinical trial is now underway to validate the safety and usefulness of PLLA stents in humans.     

Experimental and Clinical Studies of Biodegradable Polymeric Stents

The metallic stent has become the most common device to reduce acute occlusion and late restenosis after balloon angioplasty, but the long-term effects of metallic stents in human coronary arteries are still unknown. To overcome several problems of conventional stenting, there have been many attempts to manufacture stents made of biodegradable materials. Although some studies have noted various degrees of inflammatory responses after biodegradable stent implantation, stents made of poly-1-lactic acid (PLLA) showed high biocompatibility with minimal inflammatory response and neointimal formation in porcine coronary arteries. A clinical study of PLLA self-expanding stent implantation is underway in Japan. The initial and 6-month results are favorable and suggest the feasibility, safety, and efficacy of the PLLA biodegradable stent in humans. However, long-term follow-up with larger numbers of patients will be required to validate the long-term efficacy of PLLA stents.     

Functional Communication Between Cardiac ATPSensitive K+ Channel and Na/K ATPase

K_ATP Channel and Na/K ATPase. Introduction: Functional interaction between K_ATP channel and Na/K ATPase was studied in single guinea pig ventricular myocytes because both membrane molecules are known to he involved in ischemic episodes. Methods and Results: K_ATP channel currents were recorded at 36°C by using whole cell, cell attached, inside-out, and open cell-attached modes of patch clamp techniques on enzymatically isolated ventricular myocytes. In the whole cell mode, ouabain (1 μM) reversibly inhibited the K_ATP currents induced by metabolic stress (ATP-free pipette solution and 1 mM NaCN), but not those activated by cromakalim (100 μM), a K_ATP channel opener. In the cell-attached mode, ouabain concentration dependently inhibited K_ATP, channel opening induced by metabolic suppression (5.5 μM 2-deoxyglucose and 1 mM CN). Half-inhibition concentration for ouabain was 21.0 ± 5.5 nM and the Hill coefficient was 0.8 ± 0.1 (n = 26). However, ouabain did not have an effect on the channel activity induced by cromakalim (100 μM). In the inside-out mode, ouabain applied to the internal side of membrane did not affect the channel. In the open cell-attached mode made by preincubation with streptolysin-0 (0.08 U/mL), the K_ATP channels were not activated by the metabolic inhibitors but were by reducing extracellular ATP concentrations, because subsarcolenimal ATP concentration could he controlled through tiny membrane holes. The channels thus activated were not suppressed by ouabain. Conclusion: The inhibition of Na/K ATPase by ouahain appeared to block the K_ATP channels by accumulating subsarcolemmal ATP caused by a decrease of the transition from ATP to ADP. In the presence of ischemic episodes, the administration of digitalis compounds may affect the opening of K_ATP channels, which is primarily protective against the development of irreversible myocardial damage.     

CASE REPORT: Steatonecrosis in the upper abdomen following transcatheter arterial embolization for hepatocellular carcinoma

A 66-year-old female with liver cirrhosis was treated by transcatheter arterial embolization (TAE) for a small hepatocellular carcinoma. She developed steatonecrosis with tenderness which occurred in the upper abdomen after TAE. The hepatic falciform artery from the middle hepatic artery was detected by arteriography. Necrosis in the upper abdomen was considered to be due to ischaemic changes caused by micromaterials for embolization of this artery, injuries of hepatic arterial endothelia slowly caused by carcinostatics, and chemotoxicity. It was considered that such complication as observed in this patient should be taken into consideration when performing TAE.     

Effect of diatrizoate meglumine (Hypaque) on the perilymphatic oxygen tension

The effect of diatrizoate meglumine (Hypaque) upon the perilymphatic oxygenation has been investigated using the polarographic method in cats submitted to various conditions such as normoxia, apnea, hypercapnea and chronically reduced vascularization. The minimal changes of the perilymphatic PO₂ recorded after the injection of Hypaque permit to conclude that this drug has no practical effect upon the oxygenation of the perilymph.     

Calcification of basal ganglia in a patient with partial trisomy 5q and partial monosomy 18q

A patient with partial trisomy for the distal segment of the long arm of chromosome 5 (q35.1 ← qter) with partial 18q monosomy is presented. The mother of the patient was phenotypically normal and was proved to be a carrier of a reciprocal translocation of the long arm of chromosomes 5 and 18 46,XX,t(5;18)(q35.1;q23). The patient shows mild mental retardation, short stature, mild obesity, dysmorphic face, eczema, minor malformations of the extremities, and bilateral intracranial calcification in the basal ganglia. Most of the clinical manifestations of the patient are compatible with the previously reported clinical features of partial trisomy of the distal segment of 5q. However, the calcification of bilateral basal ganglia has not been reported for this chromosomal anomaly.     

The close relationship between interleukin-1 and fibroblast proliferating factor from peripheral mononuclear cells of patients with chronic hepatitis and liver cirrhosis

The role of peripheral mononuclear cells (PMNC) was investigated in patients with hepatic fibrosis of chronic hepatitis or liver cirrhosis. PMNC from these patients released more fibroblast proliferating factor (FPF) in the conditioned medium than those PMNC from normal subjects in response to PHA stimulation. Production of FPF by PMNC from CAH patients was also observed in response to liver specific protein (LSP) which might act as a naturally occurring antigen in vivo. Analysis of FPF on gel permeation chromatography revealed two active components with molecular weight of 60000 (FPF-1) and 18000 (FPF-II). Both FPF-I and FPF-II exerted thymocyte proliferating activity, but not cytotoxic T cell line (CTLL) proliferating activity, indicating that they are closely related to interleukin-1 (IL-1). Isoelectrofocusing of FPF-I and FPF-II disclosed that each factor consisted of two peaks at similar pI: 5.3 and 7.0. Taking account of the fact the IL-1 consisted of two molecular forms of pI—5.4 (IL-1α) and 7.0 (IL-1β)—FPF-II is considered to be IL-1, which is a mixture of IL-1α and IL-1β, and FPF-I is probably the aggregated form of FPF-II. This assumption was further supported by the evidence that macrophages, which are the major source of IL-1 in patients with chronic hepatitis or liver cirrhosis, also released significantly higher amounts of FPF than those from normal subjects in response to stimulation by lipopolysaccharide. It was therefore concluded that in chronic hepatitis and liver cirrhosis, production of an IL-1, or a factor similar to IL-1, by PMNC is increased in response to mitogen or LPS.