Effects of degranulation of mast cells on proliferation of mesenchymal cells in the mesentery of mice

A mast-cell activator, compound 48/80, causes proliferation of mesenchymal cells in the mesentery of rats. Its effect on W/Wv mice deficient in mast cells was tested to determine whether the proliferation is mediated in the degranulation of mast cells. Incorporation of [3H]thymidine into mesenchymal cells in the mesentery of these mice with or without compound 48/80 was very small compared to their normal litter mates. However, bone marrow transplantation markedly enhanced the effect of compound 48/80, and resulted in an incorporation of [3H]thymidine almost comparable to that observed in normal mice. Our results provide evidence that mesenchymal cell proliferation is caused by a product secreted by mast cells when stimulated by compound 48/80.

Polymyositis associated with dissecting aneurysm of arteries and intracerebral hemorrhage

Dissecting aneurysm and stroke are a rare complication of polymyositis. The present report describes an autopsy case of a 53-year-old woman, who suffered from polymyositis accompanied by dissecting aneurysms of right external iliac and right renal arteries, and furthermore, intracerebral hemorrhage. The latter was caused by necrotizing angiitis. The patient had no abnormal anatomical changes such as coarctation of aorta, aortic stenosis, bicuspid aortic valve or Marfan's syndrome. Atherosclerosis in the patient was mild, and cystic medial necrosis of aorta and arteries was not found. Since the patient was attacked by dissections of arteries following long-term steroid therapy, a possibility can be raised that arterial dissection was attributable to steroid treatment besides necrotizing angiitis complicating in polymyositis.

Higher susceptibility of mast-cell-deficient W/WV mutant mice to brain thromboembolism and mortality caused by intravenous injection of India ink

(WB X C57BL/6)F1-W/WV mice possess a genetic defect in multipotential hematopoietic stem cells; the mice are anemic and lack mast cells. The authors injected diluted India ink intravenously into W/WV mice and congenic normal +/+ mice and searched for genetically determined differences in the development of complications of the injection. In both W/WV and +/+ mice, intravenous ink resulted in thrombocytopenia and markedly prolonged bleeding times, as well as prolonged partial thromboplastin and prothrombin times and reduced fibrinogen concentrations. These effects were similar in W/WV and +/+ mice, although the reduction in platelet counts was greater in W/WV mice. In addition, the mortality associated with ink injection was significantly higher in W/WV mice than in congenic +/+ mice. Most W/WV mice which died first exhibited paralysis, and examination under the dissection microscope revealed that ink injection resulted in significantly more cerebral thromboemboli in W/WV mice than in +/+ controls. Bone marrow transplantation from +/+ mice corrected both the mast cell deficiency and the anemia of W/WV mice and protected the W/WV recipients from the adverse consequences of ink injection. By contrast, +/+ mice rendered as anemic as W/WV mice by breeding did not exhibit increased morbidity and mortality after ink injection. (WC X C57BL/6)F1-Sl/Sld mice, which are anemic and lack mast cells because of a genetic defect different from that of W/WV mice, also exhibited increased morbidity and mortality after intravenous ink. Finally, mixture of ink with commercial heparin prior to intravenous injection markedly reduced the incidence of cerebral thromboembolism and death in W/WV mice. Taken together, these findings suggest that the increased morbidity and mortality exhibited by W/WV and Sl/Sld mice that received injected ink might be related to their mast cell deficiency rather than to their anemia. But measurement of the histamine content of the blood and various tissues of WBB6F1-+/+ mice injected with ink, and examination of their tissues in 1-mu sections, indicated that intravenous ink did not cause substantial mast cell degranulation. As a result, the possibility that mast cells protect +/+ mice from the adverse effects of intravenous ink by a mechanism other than degranulation and release of heparin, or that the differences in the response of W/WV or Sl/Sld mice and their +/+ littermates are due to defects other than their lack of mast cells, cannot be excluded.

Thrombus formation by the application of thrombin to the outer surface of mouse mesenteric vein: comparison with the application of ADP

Mesenteries of mice under anesthesia were stretched over an inverted microscope. A micropipette filled with solution containing various concentrations of ADP or thrombin was brought into contact with the outside of a mesenteric vein by micromanipulation, and then poured over the outer surface of the vein. Morphological characteristics of the thrombi and the time needed for thrombus formation were examined. Application of either thrombin or ADP to the adventitia of mesenteric veins caused thrombus formation. Although thrombi by application of ADP seemed to be anchored by direct adhesion of platelets to the exposed subendothelium, thrombi by application of thrombin seemed to be anchored by deposited fibrin.

Expression in E. coli of finger-domain lacking tissue-type plasminogen activator with high fibrin affinity

Tissue-type plasminogen activator (t-PA) has a high affinity for fibrin and induces lysis of fibrin (fibrinolysis) on the surface of fibrin without degrading circulating fibrinogen. cDNA for t-PA which lacks the 'finger-domain' (the site for fibrin affinity) was isolated from Detroit 562 cells. Analysis of the nucleotide sequence revealed a lack of the sequences which code for the finger-domain. A plasmid (pDPAT 1) containing the Escherichia coli tac promoter/operator and the cDNA sequence coding for 'finger-domain lacking t-PA' was constructed for expression in E. Coli. The polypeptide so produced was a new type of t-PA lacking finger-domain, but revealed plasminogen activator activity with the function of fibrin affinity.

Cerebro-spinal infarction caused by atheromatous emboli

Cholesterol embolization to the abdominal viscera is common, but rare in the central nervous system. Fourteen cases of atheromatous embolization to the central nervous system were morphologically investigated. Among the 800 consecutive autopsy cases, 38 cases had atheromatous emboli in various organs. Cerebro-spinal infarction caused by atheromatous emboli was found in 11 cases. Infarction rate (11/14) was relatively higher than in other organs and 5 of these cases were thought to be due to direct injury to the erosive surface of the aorta; cardiac catheterization (2 cases), intra-aortic balloon pumping (2 cases), and extra-anatomical bypass graft operation (1 case). These 14 patients consisted of elderly patients (70.1 +/- 6.3 years old) usually associated with hypertension (78.6%) and diabetes mellitus (42.8%). Anatomically, aortic aneurysms were seen in 10 cases (71.4%), in which aortic arch aneurysm was seen in 6 cases. Hence, aortic mechanical procedure is of great importance for denuding atheromatous materials from erosive atherosclerosis to the central nervous system.

Three autopsy cases of progression to left ventricular dilatation in patients with hypertrophic cardiomyopathy

The hearts of three cases of congestive heart failure with dilated left ventricles developing in patients with symptomatic hypertrophic cardiomyopathy (HCM) were morphologically investigated. The results showed that disproportionate hypertrophy and dilatation of the left ventricles, accompanied by massive fibrosis and myocardial disarray, were present in the three patients. The mean percent area of fibrosis of the left ventricle was 34.7% and 47.4% at the upper third and lower third levels, respectively, and was much more frequently associated with disarray (84.4 +/- 12.3%). Moreover, the fibrosis was most extensive in the lateral wall of the left ventricle, followed by the posterior, anterior, and interventricular walls. The fibrosis was also diffuse regardless of the subendocardial or subepicardial region of the heart. The findings in the present study suggest that the disarray in this particular series of HCM might be responsible for the mechanism of the fibrosis leading to dilatation of the left ventricle.

Specific sorbent of apolipoprotein B-containing lipoproteins for plasmapheresis. Characterization and experimental use in hypercholesterolemic rabbits

Dextran sulfate was covalently bound to cellulose beads (LA01) and used as the specific sorbent of apolipoprotein B-containing lipoproteins. The binding profiles of very low density, low density, and high density lipoproteins to the material were consistent with simple Langmuir adsorption isotherms. Although the affinities of all lipoproteins for the sorbent were roughly similar, the surface area available for high density lipoprotein binding was much smaller than that for very low and low density lipoproteins (29, 927, and 1934 m2/liter of swollen beads, respectively). When human plasma was passed through a sorbent column, very low and low density lipoproteins were selectively adsorbed, while almost all the high density lipoproteins were recovered from the column together with the other major plasma components. An extracorporeal circulation system with this sorbent was used for the treatment of hypercholesterolemic rabbits (diet-induced and homozygous WHHL). With a 25 ml sorbent column, very low and low density lipoproteins were selectively removed from rabbit plasma, resulting in a reduction of plasma cholesterol concentration by 300 mg/dl.

Trisomy 16q13----qter in a infant from a t(11;16)(q25;q13) translocation-carrier father

A female infant with 16q trisomy resulting from a paternally inherited balanced translocation is described and compared with five previously reported cases. All the babies were of low birth weight and expired within 1 year, with only one exception. Necropsy of the present case revealed atrial septal defect, single left lobe of the lung, anomalous lobulation of the liver, agenesis of the gall bladder, and anovestibular fistula.

Deciduoma formation in uterus of genetically mast cell-deficient W/Wv mice

The role of mast cells in deciduoma formation in the uterus of mice was investigated by using genetically mast cell-deficient (WB x C57BL/6)F1-W/Wv (hereafter called WBB6F1-W/Wv) mice. Deciduoma formation occurred in castrated WBB6F1-W/Wv mice after estradiol-progesterone injection and traumatization in spite of their deficiency of mast cells. Injection of diphenhydramine, which blocks histamine receptors, inhibited deciduoma formation in WBB6F1-W/Wv mice as well as in congenic +/+ mice. THe uterus of WBB6F1-W/Wv mice contained about 10% of the amount of histamine found in the uterus of +/+ mice. These results suggest that mast cells are not essential for formation of deciduomata and that histamine originating from sources other than mast cells may be important in deciduoma formation.

Distribution of mast-cell precursors in hematopoeitic and lymphopoietic tissues of mice

Two experimental systems were used to investigate the origin of precursor cells which differentiate into tissue mast cells in vivo. (a) Increase of mast cell number was examined in the skin, stomach, cecum, and mesentery of genetically mast cell-depleted WBB6F1 (WB X C57BL/6)-W/WV mice after the injection of various hematolymphoid cells of congenic +/+ mice. (b) Appearance of mast cells with giant granules was studied in irradiated C57BL/6-+/+ mice after the injection of lymphoid cells of C57BL/6-bgJ/bgJ (beige, Chediak-Higashi syndrome) mice. Concentrations of mast cell precursors in the thymus, lymph node and Peyer's patch were less than 0.1% of the concentration in the bone marrow. Neither treatment of donor bone marrow cells with anti-Thy-1.2 serum and complement nor thymectomy of the recipient mice affects the development of mast cells in the skin, stomach, cecum, and mesentery. Moreover, the number of mast cells increased to normal level when the skin of WBB6F1-W/WV mice was grafted on the back of nude athymic (BALB/c-nu/nu) mice. These results indicate that mast cell precursors are derived from hematopoietic tissues rather than lymphopoetic ones and that the differentiation of the precursor cells does not depend on T lymphocytes or the thymus.

Clonal nature of mast-cell clusters formed in W/Wv mice after bone marrow transplantation

We have recently found that the number of mast cells in the skin of adult W/Wv mice is less than 1% of that observed in congeneic +/+ mice, and that no mast cells are detected in other tissues of W/Wv mice. After the transplantation of bone marrow cells from congeneic +/+ mice, the number of mast cells in the skin, stomach, caecum and mesentery of the W/Wv mice increased to levels similar to those of the +/+ mice. Study of the mast-cell number in the W/Wv mice at various times after transplantation suggested to use that mast cells might develop in groups, particularly in the skin and mesentery. In this report, we have attempted to elucidate the possible clonal origin of such mast-cell clusters from a single precursor cell, using giant granules of beige (C57BL/6-bgJ/bgJ, Chediak-Higashi syndrome) mice as a marker to identify the origin of the mast cells (Fig. 1). We found that when WB-W/+xC57BL/6-Wv (WBB6F1)-W/Wv mice were injected with a mixture of bone marrow cells from beige C57BL/6 mice and normal C57BL/6 mice, more than 95% of mast-cell clusters consisted of either beige-type cells alone or normal-type cells alone. We conclude, therefore, that the cluster of mast cells originated from a single precursor cell.

Presence of mast cell precursors in peripheral blood of mice demonstrated by parabiosis

The presence of mast cell precursors in peripheral blood was examined. The beige C57BL/6 (bgj/bgj, Chediak-Higashi syndrome) mouse was parabiosed with the normal C57BL/6 mouse. Mast cells containing giant granules and originating in the beige partner appeared in the normal parabiont. A comparable proportion of normal-mouse-type mast cells developed in the beige parabiont as well. In spite of the low radiosensitivity of mature mast cells, irradiation of the normal parabiont reduced the proportion of normal-mouse-type mast cells appearing in the beige partner. It was concluded, therefore, that the precursors of mast cells can migrate through the bloodstream.

Local development of mast cells from bone marrow-derived precursors in the skin of mice

A mechanism to control development of mast cells was investigated in mice. Although mast cells in the skin of normal C57BL/6 mice were still of host type 290 days after irradiation and injection of bone marrow cells from beige (Chediak-Higashi syndrome, C57BL/6 bgJ/bgJ) mice, donor-type mast cells with giant granules appeared after painting of methylcholanthrene on the dorsal skin. Since donor-type mast cells appeared only at the painted portion of the skin, with an increase in the labeling index of such donor-type mast cells with 3H-thymidine, proliferation and differentiation of bone marrow-derived precursors of mast cells seem to be controlled locally. Although the morphologic feature of marrow-derived precursors was not identified, the finding that all fibroblasts cultured from the methylcholanthrene-treated skin were of host type may exclude the possibility that fibroblasts are the precursors of mast cells.

Decrease of mast cells in W/Wv mice and their increase by bone marrow transplantation

Production of tissue mast cells was evaluated in genetically anemic mice of W/Wv genotype and was found to be abnormal. In the skin of adult W/Wv mice the number of mast cells/cm was less than 1% of the number observed in the congeneic +/+ mice. No mast cells were detectable in other tissues of the W/Wv mice. After transplantation of bone marrow cells from +/+ mice the number of mast cells in the skin, stomach, caecum, and mesentery of the W/Wv mice increased to levels similar to those of the +/+ mice. These results show that the W/Wv mouse is a useful tool for the investigations concerning the physiologic roles and the origin of mast cells.