A strong candidate for the breast and ovarian cancer susceptibility gene BRCA1

A strong candidate for the 17q-linked BRCA1 gene, which influences susceptibility to breast and ovarian cancer, has been identified by positional cloning methods. Probable predisposing mutations have been detected in five of eight kindreds presumed to segregate BRCA1 susceptibility alleles. The mutations include an 11-base pair deletion, a 1-base pair insertion, a stop codon, a missense substitution, and an inferred regulatory mutation. The BRCA1 gene is expressed in numerous tissues, including breast and ovary, and encodes a predicted protein of 1863 amino acids. This protein contains a zinc finger domain in its amino-terminal region, but is otherwise unrelated to previously described proteins. Identification of BRCA1 should facilitate early diagnosis of breast and ovarian cancer susceptibility in some individuals as well as a better understanding of breast cancer biology.

Expression of Fas antigen on keratinocytes in vivo and induction of apoptosis in cultured keratinocytes

Fas antigen, which belongs to a nerve growth factor/tumor necrosis factor receptor superfamily, is a membrane protein that induces apoptosis. In humans, distribution of Fas antigen has been reported on cell lines and lymphocytes. Immunohistochemical studies revealed Fas antigen on the keratinocytes of lesional epidermis in lichenoid drug eruption, erythema multiforme, contact dermatitis, bullous pemphigoid, pemphigus vulgaris, and herpes zoster; it is co-expressed with intercellular adhesion molecule-1. Cultured keratinocytes expressing Fas antigen increased from 8.4% to 34.6% after stimulation with interferon gamma for 24 h. Treatment of interferon-gamma-stimulated keratinocytes with anti-Fas for 48 h resulted in DNA fragmentation and death of 32% of cells, suggesting that Fas antigen may mediate apoptosis. The expression of Fas antigen on keratinocytes in lesional skin suggests that death via Fas antigen may play an important role in the pathogenesis of keratinocyte cytotoxicity.

Analysis of the p16 gene (CDKN2) as a candidate for the chromosome 9p melanoma susceptibility locus

A locus for familial melanoma, MLM, has been mapped within the same interval on chromosome 9p21 as the gene for a putative cell cycle regulator, p16INK4 (CDKN2) MTS1. This gene is homozygously deleted from many tumour cell lines including melanomas, suggesting that CDKN2 is a good candidate for MLM. We have analysed CDKN2 coding sequences in pedigrees segregating 9p melanoma susceptibility and 38 other melanoma-prone families. In only two families were potential predisposing mutations identified. No evidence was found for heterozygous deletions of CDKN2 in the germline of melanoma-prone individuals. The low frequency of potential predisposing mutations detected suggests that either the majority of mutations fall outside the CDKN2 coding sequence or that CDKN2 is not MLM.

Isolation of a diverged homeobox gene, MOX1, from the BRCA1 region on 17q21 by solution hybrid capture

Using the technique of solution hybridization coupled with magnetic bead capture, we have isolated a novel homeobox-containing gene from the BRCA1 region of 17q21. This gene is the human homologue of the mouse Mox1 gene previously localized to a syntenic region of mouse chromosome 11. Multiple overlapping cDNAs of human MOX1 were identified using both a cosmid and a P1 genomic clone containing the microsatellite markers D17S750 and D17S858 which map within the BRCA1 region defined by D17S776 and D17S78. MOX1 expression was observed in a variety of normal tissues examined, including breast and ovary. Given that the gene contains a homeobox domain and has the potential to regulate growth and differentiation, MOX1 represents an attractive candidate for the BRCA1 gene. This possibility was investigated in a series of BRCA1 kindreds and primary sporadic breast tumors. No evidence for mutation was found in the coding sequence, making it unlikely that MOX1 is the BRCA1 gene. However, the widespread expression of MOX1 in non-embryonal tissues suggests a role in normal cell biology which warrants further study.

Epidural venous system (meningorachidian venous plexus) in juvenile amyotrophy of distal upper extremity: assessment with GD-DTPA enhanced volumetric MR study

The epidural venous system (meningorachidian venous plexus) was analyzed utilizing gadolinium-diethylenetriamine pentaacetic acid (DTPA) (Gd-DTPA) enhanced volumetric magnetic resonance (MR) images in 11 patients with focal cervical spinal cord atrophy, clinically consistent with juvenile amyotrophy of distal upper extremity. In our series, all of the patients showed unusual posterior epidural venous enhancement at the C5-6 level, suggesting posterior epidural venous dilatation. Three patients also showed prominent dilatation of cervico-thoracic epidural veins surrounding the thecal sac. These MR findings were also demonstrated by spinal phlebography. Gd-DTPA enhanced MR images, especially high resolutional volumetric MR images, were efficient for evaluating these vessels. The observation of meningorachidian venous plexus along the disease course should be necessary for searching the pathogenesis of this disease.

Decrease in myeloperoxidase during differentiation of bone marrow cells by colony-stimulating factor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) induced the proliferation and differentiation of bone marrow cells of normal mice with a concomitant loss of myeloperoxidase activity. The decrease in the enzyme activity was due to a reduced level in the bone marrow cells. These findings indicate that myeloperoxidase is not merely a marker, but may also play a role in the differentiation of stem cells into granulocytes.

Inducible binding of human lymphocytes to hyaluronate via CD44 does not require cytoskeleton association but does require new protein synthesis

We have examined molecular mechanisms of the PMA-inducible HA binding ability of human lymphocytes. Newly established OS/6 and OS/37, specific for human CD44, specifically inhibited PMA-induced HA binding of several human cell lines, suggesting that both mAb detect HA binding epitope(s) on CD44. Sequential staining revealed that these mAb cross-blocked each other's binding to Molt-4, T lymphoblast lines, and that neither of them interfered with staining of Molt-4 by other anti-CD44 mAb which induced significant homotypic cell aggregation. Biochemical and PCR analyses did not provide any evidence that PMA stimulation induced dramatic changes in molecular weight or molecular isoforms of CD44. Interestingly, HA binding was not affected and rather slightly increased by cytochalasin B which disrupts F-actin microfilament integrity. This suggests that the ability of CD44 to bind to HA does not correlate with the association of CD44 with the cytoskeleton. On the other hand, protein synthesis inhibitors, cycloheximide and anisomycin clearly inhibited the induction of HA binding of PMA-activated Molt-4 without affecting the expression of CD44 at the same time after stimulation. The same treatment had no effect on PMA-induced FN binding of the cells, which was mediated by VLA integrins. These results suggest that the adhesion functions of CD44 and integrins are differently regulated despite the fact that both are induced by PMA stimulation, and that new protein synthesis is essential for the PMA-induced HA binding by CD44.

Inducible binding of human lymphocytes to hyaluronate via CD44 does not require cytoskeleton association but does require new protein synthesis

We have examined molecular mechanisms of the PMA-inducible HA binding ability of human lymphocytes. Newly established OS/6 and OS/37, specific for human CD44, specifically inhibited PMA-induced HA binding of several human cell lines, suggesting that both mAb detect HA binding epitope(s) on CD44. Sequential staining revealed that these mAb cross-blocked each other's binding to Molt-4, T lymphoblast lines, and that neither of them interfered with staining of Molt-4 by other anti-CD44 mAb which induced significant homotypic cell aggregation. Biochemical and PCR analyses did not provide any evidence that PMA stimulation induced dramatic changes in molecular weight or molecular isoforms of CD44. Interestingly, HA binding was not affected and rather slightly increased by cytochalasin B which disrupts F-actin microfilament integrity. This suggests that the ability of CD44 to bind to HA does not correlate with the association of CD44 with the cytoskeleton. On the other hand, protein synthesis inhibitors, cycloheximide and anisomycin clearly inhibited the induction of HA binding of PMA-activated Molt-4 without affecting the expression of CD44 at the same time after stimulation. The same treatment had no effect on PMA-induced FN binding of the cells, which was mediated by VLA integrins. These results suggest that the adhesion functions of CD44 and integrins are differently regulated despite the fact that both are induced by PMA stimulation, and that new protein synthesis is essential for the PMA-induced HA binding by CD44.

Proteus syndrome

Proteus syndrome is a rare hamartomatous syndrome with a variety of abnormalities. A 6-year-old Japanese boy without apparent abnormalities at birth developed by 1 year of age cerebriform skin tumors on the right sole, soft masses on the left sole, palms and fingers, brownish verrucous lesions and whorled brownish patches on the right side of the neck, chest, external genitals and extremities, hemihypertrophy of the right lower extremity, lordoscoliosis, protuberance of the skull, epileptic seizures, hydrocephalus and mental retardation. This patient appears to be the second Japanese case of Proteus syndrome.

Proliferative activity of epidermal and dermal T lymphocytes in mycosis fungoides

BACKGROUND

Mycosis fungoides (MF) is histologically characterized by an accumulation of T lymphocytes (T cells) in both epidermis and dermis. However, the mechanism of the formation of Pautrier's microabscess or the maintenance of the epidermal T cells has not yet been clarified.

OBJECTIVE

The rate of proliferation of these T cells was investigated.

METHODS

The formalin-fixed, paraffin-embedded sections from 9 cases of patch/plaque stage MF were immunostained with proliferating cell nuclear antigen (PCNA).

RESULTS

The PCNA-positive T cell nuclei were found both in the epidermis (including Pautrier's microabscesses) and dermis in all the specimens. The mean PCNA indices of the T cells were 20.2 +/- 10.6% (mean +/- SD) within the epidermis and 16.8 +/- 6.5% in the dermis, which was not statistically significantly different (p > 0.05). The ratio of the PCNA index between the epidermis and dermis was 1.3 +/- 0.6, which was not apparently correlated with the duration of the disease (8.4 +/- 5.1 years).

CONCLUSION

These findings suggested that in situ proliferation might contribute to the epidermal T cell population resulting in the formation of Pautrier's microabscesses and an increase in dermal T cell volume during the course of the disease.

Localization of perforin in viral vesicles and erythema multiforme

BACKGROUND

Perforin (Pf), a pore-forming protein, is a cytolytic protein of killer cells. Its deposition in lesioned skin has not been studied.

OBJECTIVE

The purpose of this study is to show Pf deposition in the lesioned skin and Pf expression in the dermal infiltrates of various inflammatory skin diseases.

METHODS

Frozen specimens obtained from 29 patients with 5 different diseases were immunohistochemically stained.

RESULTS

Granular deposition of Pf was found in the lesioned skin in 2 out of 5 cases of viral vesicles and in 3 out of 7 cases of erythema multiforme. In the cases with Pf deposition, the percentages of Pf+ cells in the dermis were higher than in those without deposition.

CONCLUSION

Pf released from natural killer cells or cytotoxic T lymphocytes may play a role in tissue damage.

Pharmacokinetics of cyproheptadine and its metabolites in rats

To investigate the pharmacokinetics of cyproheptadine (CPH) and its metabolites, the plasma concentration and urinary excretion of CPH and its detectable metabolites were determined after intravenous (i.v.) administration of parent or synthesized metabolites to rats. The plasma CPH concentration-time course was subjected to biexponential calculation following the i.v. administration of CPH, producing the temporal and low plasma concentrations of desmethylcyproheptadine (DMCPH) and the sustained plasma concentrations of desmethylcyproheptadine-epoxide (DMCPHepo). DMCPH was also eliminated, according to the biexponential equation, after i.v. administration of performed DMCPH, forming DMCPHepo in plasma. On the other hand, no detectable DMCPHepo was found in plasma after the i.v. administration of cyproheptadine epoxide (CPHepo). All compounds administered had large distribution volumes and were almost entirely excreted as DMCPHepo in urine; this excretion continued for a long time. However, the urinary excretion pattern of DMCPHepo after CPHepo was different from those after CPH and DMCPH. The mean residence times of the epoxidized metabolites estimated from the urinary data were much longer than those from the plasma concentration data, suggesting either a gradual reflux of the metabolites from a tissue depot into systemic circulation under those plasma concentrations close of detection limit, or some interaction which delays excretion into the urine. This study suggests that both metabolic pathways of CPH, through DMCPH and CPHepo, to DMCPHepo are possible, but that the demethylation of CPH largely occurs prior to epoxidation; also that the extensive and persistent distribution of DMCPHepo to tissues may relate to the toxicity of CPH reported in rats.

High-dose tocopherol acetate therapy in epidermolysis bullosa siblings of the Cockayne-Touraine type

We have employed a successful therapy for epidermolysis bullosa with high-dose oral tocopherol acetate. Two siblings with dominant dystrophic epidermolysis bullosa of the Cockayne-Touraine type were reported. Both siblings suffered from tense blisters and erosions healing with scars and transient milia on the extremities. Electron microscopic study of the blisters revealed a cleavage beneath the lamina densa in both siblings. High-dose oral tocopherol acetate therapy was administered to them with satisfactory clinical reduction of the blister formation.

Expression of receptors for advanced glycosylation end products on renal cell carcinoma cells in vitro

Proteins that have been modified by long-term expose to glucose accumulate advanced glycosylation end products (AGEs) as a function of protein age. In these studies, we have examined the interaction of AGE-protein with renal cell carcinoma cells (RCC) in vitro, using AGE-modified bovine serum albumin (AGE-BSA) as a probe. AGE-BSA showed tendency to induce in vitro cell growth of RCC cells and promoted the production of interleukin-6 (IL-6), an in vitro autocrine growth factor. Reverse transcriptase-polymerase chain reaction analysis revealed that RCC cells used here express mRNA for a receptor for AGEs (RAGE). These results suggested that AGEs taken up through RAGE on RCC cells might play a role in promoting the growth of RCC cells.

Vitrification of bovine embryos in a mixture of ethylene glycol and dimethyl sulfoxide

The influence of equilibration time before vitrification on the viability of vitrified morula- to blastocyst-stage bovine embryos and in vivo viability of vitrified embryos following transfer to recipients were investigated. In experiment 1, the embryos were exposed to an equilibration solution (50% VSED) containing 12.5% v/v ethylene glycol and 12.5% v/v dimethyl sulfoxide in modified Dulbecco's phosphate buffered saline with 4 mg/ml BSA (m-PBS) for 1, 2 and 5 minutes at room temperature (22 to 24 degrees C). The embryos were then placed in 15mul vitrification solution (VSED) consisting of 25% v/v ethylene glycol and 25% v/v dimethyl sulfoxide in m-PBS and were loaded into 0.25 ml plastic straws at room temperature. After 30 seconds, the straws were placed in liquid nitrogen (LN(2)) vapor for 2 minutes, plunged and stored in LN(2). To thaw, the straws were warmed in water at 20 degrees C for 15 seconds and the contents of the straws were expelled into a plastic dish. The embryos were diluted in 0.5 M sucrose + m-PBS for 5 minutes and were cultured in TCM-199 supplemented with bovine oviductal epithelial tissue. Viability of the embryos was assessed by the forming or reforming of the blastocoele after 24 hours of culture. High in vitro survival rates (73 approximately 90%) of vitrified embryos were obtained after 1 and 2 minute equilibrations, but was reduced (P<0.05) after 5 minute equilibration. In Experiment 2, morula- to blastocyst-stage embryos were vitrified after 1 minute equilibration in 50% VSED and 30 seconds of exposure to VSED. The vitrified-warmed embryos were transferred to recipient heifers at 7 days after estrus (1 embryo per recipient). Five (38%) of 13 (40%) of 10 recipients that had received blastocysts were diagnosed as pregnant using ultrasonography 60 days following transfer.

Proliferative activities in Spitz nevus compared with melanocytic nevus and malignant melanoma using expression of PCNA/cyclin and mitotic rate

Proliferative activity in Spitz nevus (SN) was determined using proliferating cell nuclear antigen (PCNA) immunostaining and by assessing the mitotic rate. It was compared with that in compound melanocytic nevus (MN) and in malignant melanoma (MM). The PCNA index (number of positive cells/1,000 tumor cells) in SN was 72.8 +/- 45.5% (mean +/- SD), which was statistically significantly higher than that in MN (7.2 +/- 2.7%) and lower than that in MM (248.5 +/- 110%). The PCNA-positive cells in SN and MM were found both in dermal and junctional nests, while those in MN were found almost exclusively in the dermal nests. The mitotic rate in SN was 1.4 +/- 0.96%, while it was nothing in MN and 5.4 +/- 4.2% in MM. There was a statistically significant correlation between the PCNA index and the mitotic rate at r = 0.8946, p < 0.001. The PCNA index, however, appeared to show the proliferative activity of SN more clearly than did the mitotic rate.

Very late antigen integrins are involved in the adhesive interaction of lymphoid cells to human gingival fibroblasts

To date, it is still unclear how the trafficking and retention of activated lymphocytes in periodontal lesions are regulated. In this study, we investigated the molecular basis for the adhesive interactions between lymphocytes and human gingival fibroblasts (HGF). Peripheral blood T lymphocytes (PBT) exhibited binding ability, but only when the calls were activated with phorbol 12-myristate 13-acetate (PMA). Among several human cell lines tested, PMA-stimulated Molt-4, a human T-cell leukaemia line, also displayed significant binding ability to HGF. In order to clarify the molecule(s) involved in this cell-cell interaction, a panel of monoclonal antibodies (mAb) was prepared to PMA-activated Molt-4 and one clone, 4-145, was selected on the basis of its ability to block the binding of PMA-activated Molt-4 to HGF. Moreover, 4-145 inhibited the binding of not only activated Molt-4 but also activated PBT and other cell types to HGF. Biochemical and flow cytometric analyses revealed that 4-145 probably recognizes the beta 1 chain of very late antigen (VLA) integrins. Blocking experiments using mAb specific for the alpha-chain of VLA integrins demonstrated the involvement of alpha 4 (VLA-4) and, to a lesser extent, alpha 5 (VLA-5) chains in the adhesive interactions between T cells and HGF. Despite the significant involvement of VLA integrins in the adhesive interaction between PBT and HGF, the binding of PBT to human dermal fibroblasts (HDF) was not abrogated by 4-145, suggesting that HGF and HDF differ in their requirement of VLA integrins for adhesion to activated PBT. Furthermore, the fact that vascular cell adhesion molecule-1 (VCAM-1), one of the ligands of VLA-4, was not detected on HGF by flow cytometry and anti-fibronectin (FN) Ab did not block the adhesive interaction to HGF suggests that not-yet-identified ligand(s) for VLA-4 might be present on HGF.

Age-related proliferative activity in dermal melanocytic naevi detected by PCNA/cyclin expression

A monoclonal antibody was used to demonstrate proliferating cell nuclear antigen in routine, formalin-fixed, paraffin-embedded tissue sections of dermal melanocytic naevi, including naevus naevocellularis partim lipomatodes, in different age-groups. The labelling indices of the melanocytic naevus cells were < 1% of those in the overlying epidermal basal cells, and showed a statistically significant decrease with ageing, and also in naevus naevocellularis partim lipomatodes, whereas the indices of the basal cells in the overlying interfollicular epidermis did not show any age-related changes.

Moebius syndrome associated with pituitary dwarfism and hypoplastic optic disc

A 17 year old male patient with Moebius syndrome with pituitary dwarfism and unilateral hypoplastic optic disc is presented. Although there have been several reports of an association of Moebius syndrome and pituitary dysfunction, growth hormone deficiency has not been reported previously. These associations may give some insight into the pathogenesis of Moebius syndrome.

Anterior pituitary gland in pregnancy: hyperintensity at MR

The authors obtained midline sagittal T1-weighted magnetic resonance images of the pituitary gland in 30 female patients: five pregnant; two postpartum; and 23 nonpregnant, of childbearing age, and without evidence of pituitary gland disorder. In pregnant and postpartum patients, the relative signal intensity of the anterior lobe compared with the pons was statistically higher than that in the control group (P < .001). In the pregnant patients, positive correlation was noted between the signal intensity ratio of the anterior lobe and the pons and gestational age. The authors believe that the hyperintensity of the anterior pituitary lobe in pregnant and postpartum patients is a physiologic variation. Because the anterior lobe of an infant may also be hyperintense on T1-weighted images and because the anterior lobes of an infant and a pregnant woman are histologically similar, the mechanism responsible for the hyperintensity in each case may be the same. It is important to know that the anterior lobe may be hyperintense in pregnant or postpartum women, especially in cases of probable pituitary gland abnormality accompanying pregnancy, such as pituitary hemorrhage, Sheehan syndrome, or lymphocytic adenohypophysitis.

Expression of scavenger receptors on renal cell carcinoma cells in vitro

Messenger RNAs and proteins of scavenger receptor thought to be macrophage specific protein were expressed in renal cell carcinoma (RCC) cells in vitro. Acetyl LDL was taken up into RCC cells and promoted the production of interleukin-6 (IL-6), an in vitro autocrine growth factor to proliferate the cells. These results suggested that RCC cells might have a scavenger pathway which has not yet been demonstrated except for macrophages.

Three-dimensional MR vascular imaging of the spine using gadolinium-DTPA

To investigate the fine vascular structures in the spinal and paraspinal region, the authors performed three-dimensional GRASS scanning after the administration of contrast material. The scan sequence was sagittal volume scan, TR/TE 100/16, with a flip angle of 45 degrees. First-order gradient moment nulling was employed. Four normal volunteers and 31 patients were studied. Using this technique, longitudinal anterior epidural veins and vertebral arteries were clearly identified. Paraspinal fine vessels of slow to moderate flow, including dilated anterior spinal artery, radiculo-medullary vein, and perimedullary coronal venous plexus, were demonstrated in pathological cases. In addition, with processing of the volume data set, phlebographic projection images of the ladder-shaped anterior epidural venous system could be generated. This method provided more detailed information on epidural and intradural vessels than conventional MR imaging.

Contrast enhanced area of posterior pituitary gland in early dynamic MRI exceeds hyperintense area on T1-weighted images

Seventeen normal pituitary glands were studied by midline sagittal (and in one case axial) dynamic MRI before and immediately after injection of Gd-DTPA, using spin-echo sequences with a short repetition time. Images were obtained at 1 min intervals for 6 min at 1.5 T. A well-defined focal area with marked enhancement was seen in the posterior portion of the pituitary gland on the first image after injection of Gd-DTPA. The size of the early enhancing area in the posterior pituitary (EEPP) was compared with the high signal of the posterior pituitary (HSPP) on the precontrast image. The EEPP was larger than the HSPP in 10 cases (59%). The two were equal in size in seven cases (41%). The EEPP was anteriorly convex in 11 cases (65%), whereas HSPP was anteriorly convex in 4 cases (24%). We believe that EEPP closely represents the real extent of the posterior lobe. Our results support the hypothesis that HSPP may involve only a portion of the posterior pituitary.