A new table-fixed soft tissue retractor for the anterior cervical spinal surgery

Since surgeons sometimes encounter difficulty in keeping self- retaining soft tissue retractors in the proper position for anterior cervical spinal surgery, we have developed a new, simple soft tissue retractor system, which is fixed to the side rails of the operating table via retractor stands. All three joints of the retractor can be tightened simultaneously with a single handle. Each of two retractor blades can keep its position independent of the other thereby maintaining a well-exposed operative field for a long period of time. Fine adjustments of the blade position, after fixation of the retractors, is possible by sliding the head of the blade assembly along the axis of a ratchet mechanism. We have used these retractors in 43 surgical exposures, including 35 for anterior cervical fusion, 2 for posterior thoraco-lumbar decompression, and 6 for carotid endarterectomy. There have been no complications related to tissue damage.

BCR-ABL induces neurite-like structures and BCR lacking the SH2-binding domain induces cell rounding in PC12 cells

The activated tyrosine kinase oncoprotein BCR-ABL is responsible for pathogenesis of Philadelphia chromosome-positive human leukemias. Because BCR carries a GAP (GTPase-activating protein) activity toward cytoskeleton-related small GTP-binding proteins, we utilized a neuronal PC12 cell system to test morphogenic potentials of BCR-ABL or BCR. We report here unique morphological phenotypes of PC12 cells expressing either BCR-ABL or a BCR mutant which lacks the SH2-binding domain (BCR Delta162-413). Although MAP kinase was not activated in PC12 cells expressing BCR-ABL, they showed incomplete neurite extensions even in the absence of the nerve growth factor (NGF). Overproduction of BCR Delta162-413 in PC12 cells, on the other hand, induced cell rounding in the absence of NGF. Interestingly, those cells could hardly make terminal differentiation in the presence of NGF and continued to grow without changing their round shape, although NGF receptor as well as MAP kinase appeared to be activated. Interestingly, the botulinum C3 toxin induced neurite-like structures in PC12 cells overexpressing BCR Delta162-413 without NGF.

Vibration-induced finger flexion reflex and inhibitory effect of acupuncture on this reflex in cervical spinal cord injury patients

The vibration-induced finger flexion reflex (VFR) and the inhibitory effect of acupuncture on this reflex were studied in five cervical spinal cord injury patients (C-SCIs). VFR, which is a tonic finger flexion reflex induced by vibratory stimulation on the finger tip, was induced before and after acupuncture was carried out on the same hand. A stainless steel needle was inserted to the Hoku point. As in healthy subjects, VFR was performed and it was significantly inhibited by acupuncture in the C-SCIs; mean maximum VFR was 204.2 +/- S.E. 68.6 g before and 119.8 +/- S.E. 42.2 g after acupuncture. The present results suggest that at least part of the reflex center for VFR is located in the spinal cord and that part of VFR inhibition by acupuncture may be mediated via the spinal cord.

Simple evaluation method of biocompatibility of artificial oxygenator hollow fiber

We made miniature modules filled with artificial oxygenator hollow fibers and conducted a simple experiment to study the effect of different membrane structures on the blood. Three types of modules were made: one filled with polyolefin, one filled with polypropylene, and a blank module. The 3 modules were connected through 3 fine tubings to one needle so that the same blood that passed through the 3 modules could be analyzed simultaneously. Nonheparinized blood was continuously withdrawn from 6 healthy volunteers using a small pump and passed through the circuit by a single pass (10 ml/min, for 10 min). Platelet count, thrombin-antithrombin complex, and complement-3 were measured in the blood collected at 10 min from the outlet of each module. The results showed significantly better biocompatibility of polyolefin than polypropylene, which is attributable to the dense layer of the blood contact surface of polyolefin fibers. This method is useful in assessing biocompatibility of various hollow fibers in a simple and safe manner.

A cAMP response element and an Ets motif are involved in the transcriptional regulation of flt-1 tyrosine kinase (vascular endothelial growth factor receptor 1) gene

The flt-1 gene encodes a transmembrane tyrosine kinase, Flt-1, a receptor for vascular endothelial growth factor. The expression of flt-1 gene is restricted to endothelial cells in vivo. To understand the molecular mechanism underlying endothelial-specific expression of this gene, we studied the functional significance of transcriptional motifs in the 200-base pair region of the human flt-1 gene promoter, which has been identified to confer cell type specificity. By point mutation analysis using chloramphenicol acetyltransferase plasmids in 293E1 cells, which express significant levels of flt-1 mRNA, we found that an Ets motif, E4, at -54 to -51 and a cAMP response element (CRE) at -83 to -76 are involved in the transcriptional regulation of this gene. Disruption of either this CRE or E4 within the promoter sequence of 90 base pairs resulted in a decrease in chloramphenicol acetyltransferase activity of 90%, indicating that co-existence of both of CRE and Ets motif E4 is necessary for transcription of the flt-1 gene. Co-transfection of an expression vector containing c-ets-1, c-ets-2, or c-erg cDNA with this 90-base pair sequence yielded a 5-8-fold elevation of chloramphenicol acetyltransferase activity, further supporting the idea that Ets family protein(s) participates in the regulation of the flt-1 gene. Gel shift assays using nuclear extracts of 293E1 and endothelial cells demonstrated the existence of protein factor(s) that specifically binds to CRE and Ets motif E4, respectively. Taken together, our results strongly suggest cooperation of a CRE and an Ets motif for the function of the flt-1 gene promoter.

A novel pathway from phosphorylation of tyrosine residues 239/240 of Shc, contributing to suppress apoptosis by IL-3

Interleukin 3 (IL-3) not only induces DNA synthesis of haematopoietic cells but also maintains their viability by suppressing apoptosis. IL-3 stimulates tyrosine phosphorylation of the Shc adaptor protein and thereby formation of a complex of Shc with Grb2 at phosphorylated tyrosine (Y) residue 317-Shc. This pathway is implicated in Ras/mitogen-activated protein kinase (MAPK) activation towards c-fos gene expression. We examined the possible involvement of Shc in the antiapoptotic activity of IL-3. Conditional overexpression of the Shc SH2 domain, a dominant-negative mutant of Shc, was found to induce apoptosis of IL-3-dependent Ba/F3 cells along with a reduction of c-myc gene expression. Apoptosis was rescued by the exogenously introduced c-myc gene. Since we identify novel tyrosine phosphorylation sites of Shc: Y239 and Y240, their role on cell survival was tested by mutational analysis. Ba/F3 cells expressing mutant Shc Y317F, which is unable to stimulate efficiently the Ras pathway, still showed resistance to apoptosis. However, cells expressing Shc Y239/240F, which is able to stimulate the Ras pathway, were sensitive to apoptosis. In these cells, induction of the c-myc gene was reduced. These findings suggest that a new signalling pathway for cell survival is generated from Y239/240 of Shc to the nuclei involving c-myc gene expression.

CD43 expression in a B cell lymphoma, WEHI 231, reduces susceptibility to G1 arrest and extends survival in culture upon serum depletion

CD43 is a major surface sialoprotein on hemopoietic cells, whose extracellular domain is heavily O-glycosylated. The functional role of CD43 in the hemopoietic system is not fully understood; however, it has been suggested that CD43 may have a role in cell-cell repulsion and in modifying T cell proliferation and activation. CD43 is expressed in immature B cells in the bone marrow, but not by peripheral B cells, except for B-1 B cells and plasma cells. To analyze the biological effect of CD43 in B-lineage cells, we transfected mouse CD43 cDNA into a CD43- B cell lymphoma, WEHI 231, and the growth and survival in culture were compared to those of a parental cell line, human CD8 transfectants, and CD43- revertants established from CD43+ clones. We observed that CD43 expression supported cell growth in culture upon serum reduction, whereas growth of CD43- cell lines was barely detected under this condition. CD43- cell lines accumulated in G1 phase of the cell cycle, and the numbers of viable cells were greatly reduced during culture upon serum depletion, whereas expression of CD43 reduced the susceptibility to G1 arrest and temporarily retarded the apoptotic process, which, in turn, resulted in an increase and maintenance of the number of viable cells in culture. The results suggest that CD43 may have some role in the survival and expansion of B-lineage cells. The biological effect of CD43 was initiated without stimulation by cross-linking and was significantly impaired by replacement of the extracellular domain by the human CD8 extracellular domain. The basis of these regulatory processes is discussed.

Motion and image artifacts of various intracranial aneurysm clips in a magnetic field

Deflection angles of 36 types of Sugita intracranial aneurysm clips (Elgiloy), 2 types of Yasargil clips (Phynox), a Kirschner chip (SUS316) and a silver clip were examined by suspending each in a 1.5-tesla MRI (TOSHIBA MRT-200/FXII). Image artifacts of 5 types of intracranial aneurysm clips were also studied quantitatively with respect to their ratio of artifact/actual clip size using a spin-echo sequence with T1-weighted (Time of repetition (TR) = 500 ms, Time of echo (TE) = 20 ms) and T2-weighted (TR = 2000 ms, TE = 80 ms) images. All the Sugita clips from mini type to long type showed a deflection angle of less than 1.0 degree, the Yasargil clips less than 2.0 degrees, the Kirschner chip less than 6.0 degrees, and the silver chip did not move at all. Both brands of clips are therefore suitable for intracranial applications. The artifact size was directly proportional to the clip size and weight, though the ratio of artifact/actual width tended to decrease proportionately as the actual size and weight increased. The ratio of the width seemed slightly bigger than that of the length, but the difference did not reach statistical significance. There was no significant difference in the ratio of image artifacts/clip size between T1- and T2-weighted images.

Possible mechanism of the potent vasoconstrictor responses to ryanodine in dog cerebral arteries

Isolated cerebral (basilar, posterior communicating and middle cerebral) arteries exist in a partially contracted state. To determine the Ca(2+)-buffering function of sarcoplasmic reticulum in the resting state of cerebral arteries, the effects of ryanodine that eliminates the function of sarcoplasmic reticulum, on tension and cellular Ca2+ level were compared in endothelium-denuded strips of the cerebral, coronary and mesenteric arteries of the dog. The addition of ryanodine to strips with basal tone caused a concentration-dependent contraction, which was significantly greater in the cerebral arteries than in the mesenteric or coronary artery. In the presence of 10(-5) M ryanodine, the caffeine (20 mM)-induced contraction was greatly attenuated in these arteries. After washout, the basal tone was greatly elevated in the cerebral arteries. The elevated tone was abolished by 10(-7) M nifedipine. The ryanodine-induced contractions were also abolished by 10(-7) M nifedipine. Nifedipine itself caused a relaxation from the basal tone in the cerebral arteries, suggesting the maintenance of myogenic tone. The basal Ca2+ influx in arteries measured after a 5-min incubation with 45Ca was significantly higher in the basilar artery than in the mesenteric artery. The basal Ca2+ influx was not increased by 10(-5) M ryanodine in either artery. The basal Ca2+ influx was decreased by 10(-7) M nifedipine in the basilar artery, but was unchanged in the mesenteric artery. These results suggest that: (1) the basal Ca2+ influx via L-type voltage-dependent Ca2+ channels was higher in the resting state of the cerebral arteries; (2) the greater part of the higher Ca2+ influx was buffered by Ca2+ uptake into the sarcoplasmic reticulum; and (3) therefore the functional elimination of sarcoplasmic reticulum by ryanodine caused a potent contraction in these arteries. Furthermore, the maintenance of myogenic tone in the cerebral arteries suggests that more Ca2+ enters the smooth muscle cell than the buffering ability of sarcoplasmic reticulum can handle.

Increased expressions of vascular endothelial growth factor and its receptors, flt-1 and KDR/flk-1, in regenerating rat liver

Sinusoidal endothelial cells proliferate following hepatocyte regeneration in the liver after partial resection. The expressions of vascular endothelial growth factor (VEGF) and its receptors, flt-1 and KDR/flk-1, were studied by Northern blotting in isolated rat liver cells and 70% resected rat liver. VEGF was expressed in hepatocytes immediately after isolation, and both flt-1 and KDR/flk-1 were expressed in non-parenchymal cells including sinusoidal endothelial cells. The VEGF expression in hepatocytes decreased during primary culture for 48 hr. This expression was maintained at 48 hr of culture by addition of EGF to the medium at 24 hr, increasing thereafter. VEGF, flt-1, and KDR/flk-1 were also expressed in normal rat liver. In 70% resected rat liver, VEGF expression increased with a peak at 72 hr after the operation, followed by expressions of flt-1 and KDR/flk-1 increasing between 72 and 168 hr. These results suggest that VEGF expression increases in regenerating hepatocytes, which may contribute to proliferation of sinusoidal endothelial cells of rat liver following partial resection, probably through flt-1 and KDR/flk-1 receptors upregulated on sinusoidal endothelial cells.

Effect of additional intraaortic balloon support during weaning from a left ventricular assist system

A safe and reliable method of weaning from a left ventricular assist system (LVAS) is necessary for successful circulatory support in patients with marginal heart failure. The purpose of this study is to assess the effect of additional intraaortic balloon (IAB) support during weaning from an LVAS by means of the LV pressure-volume relationship. A pneumatic LVAS with a sac-type blood pump was implanted in six adult mongrel dogs weighing 14 to 20 kg. All dogs had a drainage cannula placed in the left atrium and an outflow conduit in the ascending aorta. Hemodynamic parameters, pulmonary arterial flow, and pump output were monitored. An IAB was inserted through the groin. A conductance catheter and microtip manometer were inserted into the LV cavity. As a combination driving mode, LVAS ejection in the early diastolic phase and IAB inflation in the late diastolic phase were applied. After evaluation of baseline LV function, the pressure-volume relationship was repeatedly measured during change of driving modes as isolated LVAS, LVAS + IAB (1:1), LVAS + IAB (2:1), and isolated IAB supports. Finally, LV failure was introduced by stepwise ligation of left coronary arteries, and the LV pressure-volume relationship was measured in each driving mode. Under normal conditions, the pressure-volume loop showed no significant change among the four driving modes. In contrast, the LV pressure-volume relationship significantly improved according to the degree of additional IAB support on LVAS assistance under the condition of LV failure. These results suggest that additional IAB support might improve LV energy during weaning from an LVAS.

[Cardiac surgery in patients on chronic hemodialysis]

From March 1993 to February 1993, 36 patients with chronic renal failure underwent cardiac surgery with intraoperative hemodialysis (HD). We examined and compared the medium term results of those patients cased upon the time periods of operation and types of heart disease. With respect to the time periods of operation, the 1st term (n = 12) was between March 1985 and February 1989, and the 2nd term (n = 24) was between March 1989 and February 1993. Concerning types of disease, Group A was comprised of 24 patients with ischemic heart disease, and Group B was comprised of 12 patients with valvular or congenital heart disease. Only one early death was observed in the 1st term (8.3%: LOS). As for late death, 5 cases were observed in the 1st term (45.3%), and 2 cases were observed in the 2nd term (8.3%). The actuarial survival rate (post 3 years) was 72.7% in the 1st term and 91.3% in the 2nd term. In each case, the survival rate of the 2nd term was significantly better than the that of the 1st term (p < 0.025). When compared cased upon the types of disease, the actuarial survival rate (post 6 years) was 84.6% in Group A, and 45.5% in Group B, respectively. This difference was statistically significant (p < 0.05). Causes of late death were cerebral hemorrhage in 5 cases, sudden and unknown in one and DIC in the remaining one patient. There were many postoperative complications in this series in addition to the above stated fatal ones. The majority of them, however, were successfully treated, if early diagnosis of them was obtained. During the perioperative period through the long-term period, incidents of fatal hemorrhage among patients on chronic dialysis were reduced by 1) strict management of hypertension; 2) HD without use of Heparin; and 3) with respect to patients who required Warfarin after valve replacement, through the careful anti-coagulant therapy which maintained the thrombo-test (TT) value at precise levels.

Neuroprotective properties of a protein kinase inhibitor against ischaemia-induced neuronal damage in rats and gerbils

1. The neuroprotective properties of fasudil (HA1077), a novel protein kinase inhibitor, were evaluated in two animal models of cerebral ischaemia: transient bilateral carotid artery occlusion in Mongolian gerbils and cerebral microembolization in rats. 2. The cytoprotective effect of fasudil on delayed neuronal death in gerbils was compared with the effects of nimodipine, a calcium channel antagonist and ozagrel, a thromboxane A2 synthetase inhibitor. The average of the neuronal cell density in the ischaemic control group was 17.8 +/- 2.1 cells mm-1, whereas fasudil (30 mg kg-1) significantly diminished the loss of CA1 neurones with the average of the neuronal cell density of 101.0 +/- 22.0 cells mm-1; nimodipine (10 mg kg-1) and ozagrel (30 mg kg-1) did not significantly protect against the ischaemia-induced neuronal loss. 3. In the rat model, the effects of fasudil on the histological and neurological consequences of cerebral microembolization produced via the injection of microspheres were examined. Twenty-four hours after the injection of microspheres into the internal carotid artery, all animals in the control group showed typical symptoms of stroke. Neurological function was significantly improved in the fasudil-treated animals. In the controls, the infarcted area in a cortical slice selected to include the hippocampal area was 0.25 +/- 0.01 cm2 (mean +/- s.e.mean) (43.9 +/- 2.4% of cortical section of the half hemisphere); the difference was significant compared to the mean area of 32.7 +/- 2.8 and 21.5 +/- 4.8% observed in rats treated with fasudil (3, 10 mg kg-1), respectively. Fasudil (10 mg kg-1) significantly suppressed the increased water content in ischaemic brain tissues (saline-treated rats, 82.4 +/- 0.2% vs fasudil-treated rats, 81.0 +/- 0.4%). 4. These results suggest that: (i) various protein kinases are involved in the pathogenesis of ischaemic injury; and (ii) the inhibition of protein kinases may be efficacious in preventing neuronal death, thus improving neurological function in the brain damage associated with ischaemic stroke.

Changes in serum cytokine concentrations after neurosurgical procedures

Cytokine responses to surgical trauma have been studied in 70 patients undergoing various neurosurgical procedures. Serum concentrations of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), interleukin-8, (IL-8), tumour necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) were measured before and after surgery using enzyme-linked immunosorbent assays. The serum concentrations of IL-1 beta, IL-8, TNF-alpha, and IFN-gamma did not change significantly following neurosurgical operations. In contrast, serum IL-6 levels were significantly elevated following surgery, peaking at postoperative day 1 and then gradually decreasing. Maximum IL-6 concentrations were considerably higher in patients who underwent surgery for brain tumours or aneurysms as compared with patients who had a ventriculoperitoneal shunt, neurovascular decompression or transsphenoidal adenomectomy. Intra-operative use of methylprednisolone, which is known to block the production and action of cytokines, suppressed the increase in IL-6 levels after surgery. There was a statistically significant correlation between the IL-6 peak concentration and the length of surgery in patients not treated with steroids, but not in patients treated with steroids. Additionally patients who underwent supratentorial surgery had higher peak concentrations of IL-6 than those who underwent infratentorial surgery. These results suggest that IL-6 is an early marker of tissue damage and may be useful in assessing the extent of postoperative stress.

Molecular cloning and bacterial expression of a cDNA encoding furostanol glycoside 26-O-beta-glucosidase of Costus speciosus

Furostanol glycoside 26-O-beta-glucosidase (F26G) purified from Costus speciosus rhizomes was digested with endoproteinase, and several internal peptide fragments were obtained. Degenerate oligonucleotide primers based on amino acid sequences of the peptides were used for amplification of F26G cDNA fragments by applying nested polymerase chain reactions to cDNAs from in vitro cultured plantlets of C. speciosus. Using primers based on sequences of the cDNA fragments, the 5'- and 3'-end clones were isolated by rapid amplification of cDNA ends (RACE) methods. Finally, the entire coding portion of F26G cDNA was cloned by using primers designed from sequences of the RACE products. The deduced amino acid sequence of CSF26G1, the protein encoded by the cloned cDNA, consists of 562 amino acids and shows high homology to a widely distributed family of beta-glucosidases (BGA family). Cell-free homogenate of Escherichia coli expressing CSF26G1 cDNA showed beta-glucosidase activity specific for cleavage of the C-26 glucosidic bond of furostanol glycosides.

The dimerization property of glutathione S-transferase partially reactivates Bcr-Abl lacking the oligomerization domain

Bcr-Abl oncoproteins are responsible for the pathogenesis of human leukemias with a reciprocal chromosome translocation t(9;22). The amino-terminal Bcr sequence has a potential to form a homotetramer (tetramer domain), and destructions of the tetramer domain cause a complete loss of biological activities in Bcr-Abl. Here we show that Bcr-Abl in which the tetramer domain is replaced with glutathione S-transferase (GST) with a dimerizing ability (GST/Bcr-Abl-(Delta1-160)) can no longer induce an interleukin-3 (IL-3) independence in Ba/F3 cells or transform mouse bone marrow cells but still retains by 30-40% the ability to transform Rat1 cells. Compared with the wild type Bcr-Abl, autophosphorylation of GST/Bcr-Abl-(Delta1-160) in vivo was reduced by more than 50%. The Grb-2 binding to GST/Bcr-Abl-(Delta1-160) was 50% reduced in Rat1 cells and undetectable in Ba/F3 cells. In Rat1 cells expressing GST/Bcr-Abl-(Delta1-160), phosphotyrosine contents of p62 and Shc were 70% decreased.

Bifrontal basal interhemispheric approach to craniopharyngioma resection with or without division of the anterior communicating artery

The authors describe the use of a bifrontal basal interhemispheric approach with or without division of the anterior communicating artery (ACoA) for removal of large craniopharyngiomas. This approach is a more basal modification of the anterior interhemispheric approach; allowing preservation of most bridging veins. Since 1988, 22 patients underwent operations using this approach to achieve total or near-total excision of large craniopharyngiomas. Division of the ACoA was performed in 11 of 17 patients with retrochiasmatic tumors with no early or late complications related to division of the artery. There were no operative mortalities. Visual improvement (59%) and preservation of the pituitary stalk (64%) were achieved in a high percentage of patients. Preservation of the pituitary stalk correlated well with postoperative pituitary function. The bifrontal basal interhemispheric approach allowed a bilateral, wider operative field with better orientation and views of important neural structures and perforating arteries without requiring combination with other approaches. When the ACoA limited operative exposure, the artery could be divided safely. The authors discuss indications for, and advantages of, the bifrontal basal interhemispheric approach with or without division of the ACoA in the removal of large craniopharyngiomas.

Monoclonal antibody against the fusion junction of a deletion-mutant epidermal growth factor receptor

A mouse monoclonal antibody (IgG2b), 3C10, was produced against the truncated epidermal growth factor receptor (EGFR), encoded by the (type III) in-frame deletion mutation of 801 nucleotides of EGFR affecting the external domain, known to be expressed in some human glioblastoma. As this mutation newly generates a glycine residue at the fusion point, a 14 amino acid peptide around the fusion junction including this glycine was chemically synthesised and used for immunisation of (B6 x DBA/2) F1 mice. Flow cytometric analysis showed 3C10 antibody staining of a mouse NIH/3T3 transfectant (ERM5) with the type III EGFR deletion-mutant gene, but not one with wild-type EGFR. The antibody immunoprecipitated the truncated EGFR protein with a molecular mass of approximately 140 kDa from ERM5 cells. Immunostaining of glioblastomas revealed binding in the case with the type III EGFR mutation, the five other specimens without the mutation being negative despite overexpression of EGFR in some cases.

Expression of vascular endothelial growth factor, its receptor, and other angiogenic factors in human breast cancer

Angiogenesis is essential for the growth and metastasis of solid tumors. In this study, we examined gene expression of vascular endothelial growth factor (VEGF); its receptor, flt-1; basic fibroblast growth factor; and transforming growth factors (TGFs) alpha and beta in 18 paired cases of human breast carcinomas and the adjacent nonneoplastic tissues. In all of the paired cases, VEGF expression was markedly increased in the carcinomas. In contrast, an insignificant difference was observed in the expression of flt-1, basic fibroblast growth factor, TGF-alpha, and TGF-beta between the malignant breast tissue and the nonneoplastic counterpart. Immunostaining showed variable VEGF positivity of the malignant cells, whereas the nonneoplastic breast epithelial cells were negative. The findings of this study suggest that VEGF is an important angiogenic factor in human breast cancer.

[Interphase cytogenetics of the breast tumors with fluorescence in situ hybridization (FISH) on cytologic preparation--its practice and clinical applications]

Fluorescence in situ hybridization (FISH) study with the chromosome specific probes is performed in the interphase nuclei of the routinely processed cytologic preparation of the breast tumors. Numerical aberrations on the chromosomes 1, 3, 11 or 17 were detected in more than 80% of the malignant tumors, but not in the benign tumors. Marked heterogeneity of the polysomies is noted in the malignant tumor cells. A few malignant cases revealed monosomy of chromosome 17. No apparent correlation between the numerical abnormalities and the histological features in malignant tumors is identified. These results suggest that the interphase cytogenetics with FISH for the breast tumors may be useful for differential diagnosis of malignancy. The practice and the clinical applications of the FISH study are discussed.

DOCK180, a major CRK-binding protein, alters cell morphology upon translocation to the cell membrane

CRK belongs to a family of adaptor proteins that consist mostly of SH2 and SH3 domains. Far Western blotting with CRK SH3 has demonstrated that it binds to 135- to 145-, 160-, and 180-kDa proteins. The 135- to 145-kDa protein is C3G, a CRK SH3-binding guanine nucleotide exchange protein. Here, we report on the molecular cloning of the 180-kDa protein, which is designated DOCK180 (180-kDa protein downstream of CRK). The isolated cDNA contains a 5,598-bp open reading frame encoding an 1,866-amino-acid protein. The deduced amino acid sequence did not reveal any significant homology to known proteins, except that an SH3 domain was identified at its amino terminus. To examine the function of DOCK180, a Ki-Ras farnesylation signal was fused to the carboxyl terminus of DOCK180, a strategy that has been employed successfully for activation of adaptor-binding proteins in vivo. Whereas wild-type DOCK180 accumulated diffusely in the cytoplasm and did not have any effect on cell morphology, farnesylated DOCK180 was localized on the cytoplasmic membrane and changed spindle 3T3 cells to flat, polygonal cells. These results suggest that DOCK180 is a new effector molecule which transduces signals from tyrosine kinases through the CRK adaptor protein.

Rapid enlargement of a syringomyelia cavity following syringo-subarachnoid shunt: case report

We describe a patient who presented with syringomyelia 20 years following an operation for foramen magnum meningioma. A syringo-subarachnoid shunt was placed, which connected the syrinx and the cerebello-pontine angle cistern. Following shunt placement, the patient's symptoms rapidly progressed, and magnetic resonance imaging (MRI) revealed enlargement of the syrinx. The symptoms improved with a decrease in syrinx size after placement of a syringo-peritoneal shunt in combination with revision of the syringo-subarachnoid shunt, changing the position of the subarachnoid tip to the caudal spinal subarachnoid space. The mechanism of rapid enlargement of the syrinx cavity following placement of the syringo-subarachnoid shunt is discussed.