[Multiple cerebral hemorrhages due to varicella-zoster virus vasculopathy presenting as cranial nerve palsy]

A 72-year-old man was admitted to our hospital because of right facial muscle weakness and diplopia. He had been treated for aplastic anemia with cyclosporin for 2 years. Thirteen days before admission, a diagnosis of herpes zoster was made and treated with amenamevir. On admission, neurological examination revealed mild cognitive disturbance, mydriasis, weakness of the inferior rectus muscle of the left eye, and right peripheral facial nerve palsy. Cerebrospinal fluid (CSF) analysis showed elevated leukocytes and increased protein levels. Antibody index to varicella-zoster virus (VZV) was elevated in CSF to 25.6, although VZV DNA was negative by PCR. Head CT revealed multiple intracerebral hemorrhages in the left dorsal pons, left ventral midbrain, left thalamus, and left front-parietal lobe. MR angiography detected cerebral artery stenosis. In addition to intravenous acyclovir, the patient was treated with steroid pulse therapy and steroid tapering therapy. One month after admission, his symptoms improved. We diagnosed him with VZV vasculopathy. We believe that multiple intracerebral hemorrhages due to VZV vasculopathy caused facial and oculomotor nerve palsy. Our findings suggest that cerebral hemorrhage induced by VZV vasculopathy must be considered when differentiating cranial nerve palsy after herpes zoster.

Fbxo45, a novel ubiquitin ligase, regulates synaptic activity

Neurons communicate with each other through synapses. To establish the precise yet flexible connections that make up neural networks in the brain, continuous synaptic modulation is required. The ubiquitin-proteasome system of protein degradation is one of the critical mechanisms that underlie this process, playing crucial roles in the regulation of synaptic structure and function. We identified a novel ubiquitin ligase, Fbxo45, that functions at synapses. Fbxo45 is evolutionarily conserved and selectively expressed in the nervous system. We demonstrated that the knockdown of Fbxo45 in primary cultured hippocampal neurons resulted in a greater frequency of miniature excitatory postsynaptic currents. We also found that Fbxo45 induces the degradation of a synaptic vesicle-priming factor, Munc13-1. We propose that Fbxo45 plays an important role in the regulation of neurotransmission by modulating Munc13-1 at the synapse.

Fbxw8 is essential for Cul1-Cul7 complex formation and for placental development

Cullin-based ubiquitin ligases (E3s) constitute one of the largest E3 families. Fbxw8 (also known as Fbw6 or Fbx29) is an F-box protein that is assembled with Cul7 in an SCF-like E3 complex. Here we show that Cul7 forms a heterodimeric complex with Cul1 in a manner dependent on Fbxw8. We generated mice deficient in Fbxw8 and found that Cul7 did not associate with Cul1 in cells of these mice. Two-thirds of Fbxw8-/- embryos die in utero, whereas the remaining one-third are born alive and grow to adulthood. Fbxw8-/- embryos show intrauterine growth retardation and abnormal development of the placenta, characterized by both a reduced thickness of the spongiotrophoblast layer and abnormal vessel structure in the labyrinth layer. Although the placental phenotype of Fbxw8-/- mice resembles that of Cul7-/- mice, other abnormalities of Cul7-/- mice are not apparent in Fbxw8-/- mice. These results suggest that the Cul7-based SCF-like E3 complex has both Fbxw8-dependent and Fbxw8-independent functions.

Optic neuritis and human T-lymphotropic virus type 1-associated myelopathy: a case report

A 50-year-old woman with human T-lymphotropic virus type 1-associated myelopathy developed sudden loss of vision in her left eye. The patient had a relative afferent pupillary defect and a large central scotoma on visual field examination, but no abnormal findings were apparent upon slitlamp microscopy and funduscopic examination. A diagnosis of retrobulbar optic neuritis was made. We discuss the possible association of human T-lymphotropic virus type 1 infection.

[Prevalence rate of allergy to Japanese cedar pollen in Tokyo--from field investigation in 1996 by Tokyo Japanese Cedar Pollen Allergy Measurements and Review Committee]

Prevalence rate of allergy to Japanese cedar pollen was investigated by means of questionnaires and immunological examinations in residents of 3 regions in Tokyo (Akiruno city, Chofu city, and Ota ward). The results were as follows: 1) the prevalence rate of allergy to Japanese cedar pollen in Tokyo was 25.7% in Akiruno city, 21.1% in Chofu city, and 17.7% in Ota ward in 1996; 2) stratification by the age reveal that the prevalence rate was the highest in the age group of 30 to 44, and the group showed prevalence rate of above 40% in Akiruno city; 3) overall prevalence rate of Tokyo was 19.4% in 1996, which was approximately twice as much as that in 1985; 4) increase in prevalence rate in the recent decade was most significant in Akiruno city where the largest number of Japanese cedar pollen was detected in the air, and prevalence rate tended to rise in the young group of 14 or less.

Reversible irritative effect of acute 2.45GHz microwave exposure on rabbit eyes--a preliminary evaluation

We have attempted to determine if there is a hazardous effect of acute microwaves at 2.45 GHz on the eye of a rabbit under lengthy exposure without anesthesia, the contralateral eye serving as a control. Unilateral eyes of 9 adult Japanese white rabbits (10-12 weeks of age) were irradiated by 2.45 GHz continuous wave (CW) microwave for 160 min. to 240 min. under restraint without anesthesia. The specific absorption rate (SAR: phantom material) was 26.5 W/kg. The corneal surface temperature increment was 3.0 degrees C for 15 min. on average. Miosis occurred in all rabbits within 15 min. Post-exposure ophthalmological signs, first detected as the effect of CW irradiation, included 1) miosis and pupillary congestion; 2) keratoleucoma and corneal edema; 3) endothelial cell detachment and floating in aqua oculi, 4) fibrinogenesis in the anterior chamber, and 5) conjunctiva edema, which disappeared one week after exposure. There was no cataract formation. The acute microwave irradiation to the rabbit eye, causing the miosis and pupillary congestion in all irradiated eyes, was the first to be detected.

Hemophagocytic syndrome in five patients with Epstein-Barr virus negative B-cell lymphoma

BACKGROUND

The recent recognition of the association of Epstein-Barr virus (EBV) with T-cell/natural killer cell (T/NK-cell) lymphoma has documented that particular types of EBV-containing T/NK-cell lymphoma are frequently complicated by hemophagocytic syndrome (HPS). This observation suggests that both EBV and proliferating T/NK-lymphoma cells play significant roles in the development of HPS. Cytokines released from neoplastic T cells are presumed to account for the activation of macrophages, which is followed by a complex cascade of cytokine production, resulting in full-blown HPS. Five patients with B-cell lymphoma complicated by HPS were studied for elevated serum cytokines, the association of EBV, and CD25 expression of lymphoma cells; the aim of this study was to verify whether the mechanisms of HPS development hypothesized for T/NK-cell lymphoma also operate in B-cell lymphoma.

METHODS

Sera were analyzed for the presence of inflammatory and immunoregulatory cytokines. Flow cytometry, immunohistology (IH), in situ hybridization (ISH), polymerase chain reaction (PCR), and Southern blot analysis were performed using bone marrow aspirates, biopsy specimens, and autopsy specimens.

RESULTS

Immunophenotypic and Southern blot studies verified that the lymphoma cells of all five patients were of B-cell lineage. Bone marrow aspirates demonstrated histiocytosis with extensive hemophagocytic activity. Marked elevation of serum cytokines and expression of CD25 were observed in all five patients. However, the results of PCR, ISH using EBER1 probe, and IH for latent membrane protein indicated that these lymphoma cells were free of EBV infection.

CONCLUSIONS

In patients with B-cell lymphoma, EBV infection is not necessarily required for the initiation of HPS. In this article, the pathogenesis of HPS assumed to be operative in B-cell lymphoma is discussed with reference to T/NK-cell lymphoma complicated by HPS.

[Expression of matrix metalloproteinases and tissue inhibitor of metalloproteinase by myofibroblasts--morphological study on corneal wound healing]

The matrix metalloproteinases (MMPs) and the tissue inhibitor of metalloproteinases (TIMPs) regulate the extracellular matrix and are important in the process of connective tissue remodeling. In this study, we investigated the expression of MMPs and TIMP-2 by myofibroblasts (MF) originating from keratocytes during the healing of alkali-burned and lacerated rabbit corneas. In light and/or electron microscopic immunohistochemistry, the MMP-1, 2, 9 and TIMP-2 antibodies reacted with MF in both types of corneal wounds. The clear expression of MMP-1 and the relatively faint immunoreaction of MMP-2 were observed in both types of healing from one week after wounding, while MMP-9 appeared from 3 weeks after injury. In addition, the levels of MMP-2 and 9 were increased from 4 weeks after alkali-burned injury. The clear expression of TIMP-2 was observed from 1 week after both types of wounds. These findings indicate that MF is deeply involved in degrading some of the key matrix proteins (such as type I collagen), and may play an important role in tissue remodeling in corneal wounds through production of MMPs and TIMP.

Intussusception caused by primary malignant melanoma of the small intestine

Whether melanoma develops as a primary tumor in the small bowel remains controversial. A 57-year-old male Japanese presented signs of intestinal obstruction. Ultrasonography and computed tomography disclosed an abdominal mass with multiple concentric rings, characteristic of intussusception. At surgery, a spherical tumor, 3.8 cm in diameter, with scattered pigmentation was found to lead the intussusception. Segmental intestinal resection with regional lymph node dissection was performed. Pathological examination revealed diffuse infiltration of malignant melanoma cells. Nodal metastasis was seen only in the mesenteric node draining from the tumor-bearing intestinal segment. Twelve months after surgery, melanoma recurred in the liver and para-aortic lymph nodes, where a malignancy of the digestive organs frequently metastasizes; however, no extraperitoneal melanoma was found after repeated examinations. Thus, this case suggests that primary malignant melanoma can originate in the small intestine and be a cause of intussusception in the adults.

Dynamics of the expression of cytoskeleton components and adherens molecules by fibroblastic cells in alkali-burned and lacerated corneas

To provide a better understanding of the role of fibroblastic cells during corneal wound-healing, we examined the expression of cytoskeleton components (i.e. smooth muscle alpha-actin (alpha-SMA), vimentin, desmin), adherens molecules (vinculin and talin) and cellular fibronectin in alkali-burned and lacerated rabbit corneas. Alkali-burned and lacerated corneas, which had healed for various periods of time (1 day to 45 days), were excised and subjected to immunohistochemical studies with monoclonal antibodies against alpha-SMA, vimentin, desmin, vinculin, talin and cellular fibronectin. Monoclonal antibody against alpha-SMA reacted with fibroblastic cells in injured corneas but did not react with keratocytes in normal corneas. Anti-desmin antibody did not react with any corneal cells in normal or injured corneas except the muscle cells in the newly-formed capillary of injured corneas. The results indicate that the fibroblastic cells in injured corneas have the characteristics of myofibroblasts. The number of myofibroblasts in granulation tissues increased and peaked within 3 weeks of injury and then declined. Electron microscopy revealed that some fibroblastic cells in the lacerated cornea which had healed for 4 weeks contained dense chromatins. In situ 3'-end labeling with terminal nucleotide transferase indicating that some of the fibroblastic cells contained nicked genomic DNA. These observations imply that apoptosis plays a role in regulating the number of myofibroblasts in the injured corneas. Antibodies against cellular fibronectin, vinculin and talin react with the fibroblastic cells in the injured corneas, but not with the keratocytes of normal corneas. Examination with transmission electron microscopy demonstrated the presence of microtendon and fibronexis associated with fibroblastic cells and the presence of stress fiber within fibroblastic cells. The results indicate that the fibroblastic cells may cause corneal wound contraction, which in turn contributes to the formation of opaque scar tissues.

Diffuse arteriovenous malformation involving jejunum and total colon with mesenteric varices. Case report

Diffuse intestinal arteriovenous malformation (AVM) is very rare. We describe a case of diffuse AVM involving the jejunum and the total colon in an adult. In addition, mesenteric varices without portal hypertension is demonstrated on angiography of the superior mesenteric artery. The high flow through the AVMs may be a major component in the etiology of the mesenteric varices in our case.

Abdominal wall desmoid mimicking intra-abdominal mass: MR features

A case of abdominal wall desmoid which enlarged toward the liver and mimicked an intra-abdominal tumor is presented. T*2-weighted MR images clearly demonstrated the tumor's continuity with the rectus abdominis muscle. The case presented suggests MRI may provide more valuable information concerning the origin of a right-upper-quadrant mass than CT does. However, the nature of the signals and attachment which this case showed were so unusual for desmoids that this case has not been diagnosed accurately.

Isolated angiitis of the central nervous system first presenting as intracranial hemorrhage during cesarean section

A case of isolated angiitis of the central nervous system (CNS) which first presented as intracranial hemorrhage during cesarean section is reported. Only one case of isolated angiitis of the CNS in post partum has been reported to date. Although a headache in labor and puerperium usually suggests subarachnoid hemorrhage, isolated angiitis of the CNS should be considered in the differential diagnosis.

[Inflammatory tumor of the hepatic hilus mimicking bile duct cancer--report of a case]

A 73-year-old man was admitted to our hospital because of jaundice. Ultrasonography and computed tomography showed a tumor of the hepatic hilus causing obstructive jaundice. Angiography revealed a stenosis of the right hepatic artery. Under the diagnosis of carcinoma of the hepatic hilus, extended right hepatectomy with resection of the caudate lobe was performed. A tumor showing expophytic growth, 2.1 x 1.9 x 1.5cm in size, was seen in the hepatic hilus. Histologically, the tumor was proved to be a non-neoplastic fibrous tissue simulating the inflammatory pseudotumor.

[Lipoprotein (a) and sclerotic changes in retinal arterioles]

Lipoprotein (a) (Lp(a)) has been considered an independent risk factor for arteriosclerotic disease and its role in retinal vascular changes was studied in this report. The study was made on 160 patients of age 54 and above. They were divided into four groups depending upon their clinical background with or without the presence of diabetes mellitus (DM) and cerebral infarction (CI). The retinal vascular status of the patients was studied by ophthalmoscopic examination and the findings were graded according to Scheie's classification. We found that all the patients with retinal arterial hypertension and arteriosclerosis had a significant by high level of serum Lp (a). Similarly, serum Lp (a) level was higher in the patients with DM and CI than in the control subjects. These findings suggested that Lp (a) might influence the pathological changes of senile retinal arterioles. Moreover, we found a positive linear correlation between Lp (a) and plasminogen in patients with CI.

[Activated eosinophils in vernal keratoconjunctivitis]

A recent study showed that eosinophil basic proteins in eosinophil granules tend to cause severe lesions in allergic disease. Eosinophil cationic protein (ECP) (an eosinophil basic protein), released from activated eosinophils, damages the epithelial mucosa. Vernal keratoconjunctivitis (VKC) always accompanies salient eosinophil infiltrations in the conjunctiva. To evaluate the role of activated eosinophils during VKC, we studied conjunctival specimens from VKC patients, using an immunohistochemical technique with monoclonal antibody (EG2) and electron microscope. We also determined ECP content in the patient tears. Immunocytochemical study showed a significant number of activated and degranulated eosinophils in the conjunctiva (giant papilla), including its epithelia and subepithelial tissue. Electron microscopy showed that the tear mucoid layer contained a number of exfoliated conjunctival epithelial cells with eosinophil granules. ECP content in the tears of these patients was 1361.4 +/- 1053.4 ng/ml, significantly higher than that of a normal subjects (< 20.0 ng/ml) (p < 0.01). These results suggest that the activated eosinophils and ECP contribute to the development of the lesion during VKC.

[Two cases of intrapulmonary teratoma]

We encountered two unusual cases of intrapulmonary teratoma, one in a 31-year-old female and the other in a 15-year-old female. The chief complaint of both patients was fever, and in both a consolidation was detected in the left upper lobe using routine radiography. We performed left upper lobectomy for the former patient and segmentectomy of the left lingual segment for the latter. Neither tumor communicated with the mediastinum. Histological examination revealed a pulmonary teratoma containing no thymic tissue in both. Intrapulmonary teratoma has been reported to be extremely rare, and only 27 cases including these two have been reported in the literature.

Retroperitoneal ganglioneuroma extending across the midline: MR features

A rare adult case of retroperitoneal ganglioneuroma in which magnetic resonance imaging (MRI) clearly demonstrated unusual extension of the tumor across the midline is reported. Dynamic MR imaging was very useful to distinguish benign ganglioneuroma from other retroperitoneal tumors, especially neuroblastoma and pheochromocytoma.

[Isolated angiitis of the central nervous system with high immune complex titer, first presenting as intracranial hemorrhage during cesarean section]

A case of isolated angiitis of the central nervous system (IACNS) which first presented as intracranial hemorrhage during cesarean section was reported. The patient was a 27-year-old female who showed severe headache during cesarean section. CT scan disclosed hematoma in the right parieto-occipital area. Carotid and vertebral angiograms demonstrated striking areas of stenosis and irregularity of all intracranial arteries. There was no abnormality in the branches of the external carotid arteries. Systemic angiograms showed no evidence of systemic vasculitis. Biopsy of the temporal artery showed no abnormal findings. Titer of immune complex was elevated. Angiitis showed no improvement with corticosteroid alone, but improved markedly with corticosteroid plus cyclophosphamide. Elevated titer of immune complex became normal. Treatment with a combination of corticosteroid and cyclophosphamide is recommended in IACN.

Peritoneal mesothelioma: hypertrophic gastroepiploic and omental arteries identified by radioimmune angiography

We report a first case of malignant peritoneal mesothelioma examined by radioimmune (RI) angiography with technetium-99m human serum albumin. The RI angiography clearly demonstrated the characteristic findings including hypertrophic gastroepiploic arteries and dilated omental branches. These findings may be very helpful in distinguishing malignant peritoneal mesotheliomas from peritoneal carcinomatosis.

Clinical and cytologic aspects of ocular late-phase reaction in the guinea pig

Conjunctival tissue of 12 guinea pigs (6 experimental animals, 6 controls) was sensitized with IgG1 (PCA titer 1:2,000) antisera to dinitrophenol carrier and challenged topically with hapten. Periorbital swelling, conjunctival edema and conjunctival redness were evaluated clinically at 0.5 h and hourly for 12 h, and again at 24 and 48 h. Tears were collected at each time point for cytology. Results showed an early-phase reaction (EPR) peaking at 0.5 h and a late-phase reaction (LPR) peaking at 5-7 h. Periorbital swelling was minimal 4 h after appearance of the EPR. Conjunctival edema and redness increased in both the early and late phases, but without two distinct peaks. However, individual animals in both groups did show biphasic reactions. Tear cytology showed an abnormal increase in neutrophils and eosinophils in the later time periods and was a significant way to detect ocular anaphylaxis. In conclusion, if the presence of two significant peaks of clinical inflammation after one antigen challenge is taken as the narrowest definition of a late phase in anaphylaxis, our results show an ocular LPR occurring in our animal model.

The origin of extragonadal teratoma: case report of an immature teratoma occurring in a prenatal brain

We describe a massive congenital intracranial teratoma (MCIT), which had a normal chromosome banding pattern 46,XY karyotype and a normal diploid DNA histogram, and which produced a variety of carcinoembryonic antigens. The volume density of primitive neural components (primitive neural tubes, small undifferentiated neuroepithelial cells, immature glial fibers and pigment cell components without neurofibrillar differentiation) was estimated to be 45%. We discuss the histogenesis, pathobiology and cell cycle kinetics.

Tear volume in early and late phases of ocular anaphylaxis in guinea pigs

Three models of ocular anaphylaxis containing 6 guinea pigs each were used to examine their effect on tear volume. In the first model, IgG1-rich anti-dinitrophenol (DNP) bovine gamma-globulin serum was injected subconjunctivally, and the animals were challenged 4 h later with topically applied di-DNP-lysine. In the second model, IgE-rich anti-egg albumin serum was injected subconjunctivally, and the animals were challenged 8 days later with topical instillation of egg albumin. In the third model, IgE-rich anti-egg albumin serum was injected intravenously, and animals were challenged 8 days later with topically applied egg albumin. Tears were collected before the procedure, 0.5 h after anaphylaxis was initiated, and then hourly for 8, 10, 12, 24, and 48 h after challenge. All animal eyes undergoing ocular anaphylaxis had significantly increased tearing. Tear volumes remained elevated in the first model beyond the observation period of 48 h.

Early and late phases of ocular anaphylaxis in actively immunized guinea pigs

A model of ocular anaphylaxis with distinct early- and late-phase components was studied in actively immunized guinea pigs. Twenty guinea pigs were injected with dinitrophenylated (DNP) bovine gamma globulin emulsified in Freund's complete adjuvant and challenged topically with di-DNP-lysine. Clinical signs were monitored over a 48 h period. An early-phase reaction (EPR) characterized by conjunctival edema, conjunctival erythema, lid swelling, and lid redness was observed. This reaction peaked at 0.5 h after challenge and subsided to a low point at 3-4 h. Subsequently, a second episode of lid swelling and lid redness was observed at 4-8 h. All animals in both groups exhibited an EPR. In addition, 75% of the animals underwent an EPR and an LPR. No animals exhibited an isolated LPR. Of the animals that underwent a dual response, 47% were biphasic, 6% were prolonged and 47% were multiphasic. The development of an active model of ocular anaphylaxis exhibiting both EPR and LPR components will enable studies of mechanisms which regulate the frequency and magnitude of these ocular allergic responses.

Management of multiple cholesterol embolization syndrome--a case report

A sixty-two-year-old man who underwent coronary angiography and received acute thrombolytic and anticoagulant therapy for acute myocardial infarction developed multisystemic injury, including renal insufficiency and cutaneous manifestations. Fundoscopic examination and skin biopsy specimen led to the diagnosis of multiple cholesterol embolization syndrome (MCES). Discontinuation of anticoagulants and administration of hemostatic (carbazochrome, tranexamic acid, reptilase, and vitamin K) and antihyperlipidemic (cholestyramine and probucol) drugs resulted in temporary improvement of cutaneous and renal disorders and extended survival for about one year. Besides severe aortic atherosclerosis, postmortem examination revealed numerous cholesterol emboli to multiple organs. MCES is a rare but serious complication of left heart catheterization and anticoagulant therapy, and the optimal treatment remains to be established. The authors suggest here that the above-mentioned therapy might be effective for management of MCES.

[Pleomorphic adenoma of the lung]

A 41 year-old male was admitted to our hospital, because a suspicious shadow in the right lower lung field was on X-ray. Investigations could not confirm cancer but were highly suggestive of it. Finally, right lower lobectomy was performed, and the histopathological finding of the tumor resected were a mixture of epithelial components in myxomatous tissue, so a diagnosis of pleomorphic adenoma of the lung was made.

A model for tumorigenicity and metastatic potential: growth in 1.0% agar cultures

We developed a method to determine the amount of work performed by cells through cell division in 1.0% agar cultures. There was no correlation between the cloning efficiencies of 1.0 and 0.3% agar cultures. Growth in 1.0% agar cultures correlated well with such malignant properties as tumorigenicity and the invasive and metastatic potentials. Our method revealed that metastatic MC and F cell lines possess different means of taking advantage of energy to proliferate against an environmental pressure from those possessed by nontumorigenic (ME and T-C3H) cell strain/line or nonmetastatic but tumorigenic (L,MR, and magc1) cell lines.

An improved DAPI-DNA cytofluorometry by hypotonic cytolysis. Its application to tumor cell heterogeneity

The effect of cell cytolysis on DAPI-DNA cytofluorometry was studied in order to eliminate nonspecific cytoplasmic hindrances in DAPI staining. A great improvement in the reproducibility of DNA determination was attained when cells were treated with hypotonic KCl (0.075 M) solution. The DNA content per cell of the mgC5 clonal line (normal diploid cell containing 2C DNA units) after hypotonic treatment was 3.07 +/- 0.06, while that of mgC5 cells without hypotonic treatment was 3.50 +/- 0.26, indicating a remarkable decrease from 7.4% to 2.0% in the coefficient of variation. In detecting tumor cell heterogeneity, our cytolytic method was superior to the method of counting the mode of chromosome number. The modal chromosome numbers of nontumorigenic m and its derivatives, mgC4 and mgC5, were 69, 68 and 67 respectively, while those of their tumorigenic counterparts, magc, mgC4V1 and mgC5V1 were 68, 66 and 67. The DNA contents of nontumorigenic m, mgC4 and mgC5 were 3.00 +/- 0.10 (mean +/- SD), 3.07 +/- 0.06 and 3.07 +/- 0.12, while those of their tumorigenic counterparts, magc, mgC4V1 and mgC5V1 were 3.67 +/- 0.15, 3.23 +/- 0.06, 3.27 +/- 0.06 respectively. A statistically significant difference in DNA content between the tumorigenic and nontumorigenic cells was observed at least at the p less than 0.05 level (t-test) when DNA content was employed for comparison, but not when the modal chromosome number was employed.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the colony forming ability and invasive potential of six primate cell lines treated with retinoic acid

Four human and two nonhuman primate cell lines were studied to determine their growth characteristics in soft agar, and for invasive characteristics in a muscle organ culture assay system. The cell lines ranged from normal human diploid to frankly tumorigenic in animal models. Additional studies were performed to assess the effects of retinoic acid (RA) on colony forming ability and invasion. The results showed a wide range of cloning efficiencies among the cell lines tested, as well as the degree of invasiveness. Of the soft agar growth parameters studied, colony growth index correlated best with invasion in the organ culture assay. RA significantly inhibited the growth of the tumor cells in soft agar, but failed to inhibit invasion in the organ culture assay although there was inhibition of surface proliferation. The data are consistent with the suggestion that cell proliferation and invasion are not necessarily linked characteristics.

Mathematical models of cell variation seen in a heterogeneous malignant cell population

We established mathematical models for the cell variation seen in a heterogeneous malignant cell population, with the supposition that it occurs as the result of the competition between two types of cells, (A) and (B), leading to a change of stem cells. Models I and II: In the case of differences in the ability of (A) and (B) cells to adapt themselves to an environment, the proportion of cells which are less adaptable to the environment decreases exponentially and eventually disappears. Model III supposes that under certain environmental conditions, the two types of cells exist simultaneously in fixed proportions, and transformations of (B) cell to (A) cell and of (A) cell to (B) cell occur at a certain rate but are independent of each other. This process is considered to follow the Markov's chain theory. Based on this supposition, we established Model III and introduced the concept of "coefficient of cell variation". We found that Model III fits the process of cell variation seen in m cell line and we calculated the coefficients of cell variation seen in this cell line in different environments. The possible mechanism of the cell variation of this cell line is discussed.

Chromosomal banding patterns produced by methyl green-pyronin staining after trypsin treatment

A method is described for producing banding patterns with methyl green-pyronin (MGP) stain in chromosomes of fibrosarcoma cells. 1) The stain was made by mixing equal volumes of 2% aqueous pyronin G, 2% aqueous methyl green, distilled water, and 0.1 M acetate buffer (pH 5.7). 2) Treatment with colcemide and hypotonic KCl (0.075 M) was performed as usual. 3) Metaphase chromosomes were prepared using the flame-drying technique and treated with 0.25% trypsin at 37 C for 45 to 90 seconds. Before staining, the slides were rinsed in PBS, in distilled water, and then were dipped in 0.05 M acetate buffer. 4) Chromosomes were stained for more than 20 minutes, rinsed in distilled water, and hot-air dried. Satisfactory results were obtained in uncontracted metaphase chromosomes. MGP stain has the advantage of permitting much longer trypsin treatment and staining time than the trypsin-Giemsa method while providing satisfactory banding patterns.