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PubMed1997

Morphology of the human internal vertebral venous plexus: a cadaver study after intravenous Araldite CY 221 injection.

Reviewing the literature on the vascular anatomy of the spinal epidural space, it appeared that the knowledge of the internal vertebral venous plexus is limited. Injection studies of the entire internal vertebral venous plexus after application of modern techniques, to the best of our knowledge, have never been performed. Based on the clinical importance of these structures, it was decided to study the human vertebral venous system after Araldite CY 221 injection, in order to update the morphological characteristics of the internal vertebral venous system. The vertebral venous systems of ten fresh human cadavers, between 64 and 93 years of age, were injected with Araldite CY 221 mixture. All cadavers were dissected and the posterior and anterior internal vertebral venous plexuses were studied in detail. The anterior part of the internal vertebral venous plexus is fairly constant. On the contrary, the posterior internal vertebral venous plexus showed a striking segmental and interindividual variability. In the thoracic area, two types of traversing veins are observed. Both types show a somewhat symmetrical "inversed V" configuration. No anatomical valves were observed. Nevertheless, anterograde flushing (via the femoral veins) of the vertebral venous system appeared to proceed much faster than retrograde flushing (via the superior vena cava). The classical picture of the internal vertebral venous plexus appears a simplification of the actual situation. Especially in the posterior part, segmental and interindividual differences are prominent. The preferential direction of the flow during flushing suggests the presence of functional valves, which are probably located in the thoracic part of the posterior internal vertebral venous plexus, resulting from the typical shape of the veins in this area. This might explain the difficulties with imaging of the posterior part of the internal vertebral venous plexus in vitro as well as in vivo. Further study is needed to determine whether the configuration of the posterior internal vertebral venous plexus in younger individuals is different, compared with the presently studied aged subjects.

Aged↗
PubMed1990

Cross-sectional internal diameters of human cervical and femoral blood vessels: relationship to subject's sex, age, body size.

Cross-sectional internal diameter measurements were made of right and left common carotid and right femoral arteries and right and left internal jugular, superficial femoral, and common femoral veins in 32 normal human subjects utilizing duplex ultrasonography. The relationships of these vessel sizes to the subject's sex, age, height, weight, and body surface area were analyzed statistically; and graphs were constructed, indicating the relationship of blood vessel diameters to the various body size parameters. Findings indicate that 1) for the femoral veins, body surface area had the best correlation with the internal diameter of the vein; 2) for the right internal jugular vein, body weight had the best correlation with the internal diameter of the vein; 3) correlation between vein diameter and body size of the subject is better for the femoral veins than for the internal jugular veins; 4) internal diameter of the femoral and internal jugular veins increases about 20% when they are distended by 15 degrees of positional inclination of the subject's body; 5) neither age nor sex of the subject influences the positional distensibility of the veins examined; 6) the cross-sectional internal diameter of the femoral and internal jugular veins, as determined by duplex ultrasonography, closely relates to the external diameter of these vessels as measured by direct in vivo application of calipers and to the maximum outside diameter of cannula the vessel will accept.

Adolescent↗
PubMed1997

The C terminus of the human C5a receptor (CD88) is required for normal ligand-dependent receptor internalization.

The biological effects of the potent inflammatory mediator C5a, a complement split product, on human neutrophils and monocytes are limited by the rapid internalization of its specific receptor (C5aR, CD88). The C terminus of the C5aR is phosphorylated after stimulation with C5a of phorbol ester, and this phosphorylation might lead to receptor internalization. In this context, we have studied the effects on C5aR internalization of C5a, phorbol 12-myristate 13-acetate (PMA), the protein kinase inhibitor staurosporine, and pertussis toxin on rat basophilic RBL.2H3 cells stably transfected with the human wild-type or mutant C5aR. C5aR mutants lacked either part of the cytosolic C terminus, including suggested major phosphorylation sites, or a putative phosphorylation motif for protein kinase C in the third cytosolic loop. Additionally, agonist-induced internalization was analyzed on HEK293 cells co-transfected with C5aR and the pertussis toxin-resistant G protein alpha subunit, G alpha 16. Staurosporine-sensitive agonist-dependent C5aR internalization could be detected, suggesting that C5aR phosphorylation, most likely of the C terminus, participates in this type of internalization. In contrast, PMA-induced C5aR internalization seems to be independent of putative phosphorylation sites in either the truncated section of the C terminus or the third cytosolic loop. The phorbol ester-induced C5aR internalization may, therefore, be caused by an indirect and less specific effect of protein kinase C on the internalization machinery. Manipulation of the pertussis toxin-sensitive or -resistant G protein-dependent signal transduction had no effect on ligand-induced internalization.

Animals↗
PubMed1991

Multiple pathways for ligand internalization in rat hepatocytes. I: Effects of anoxia, phenylarsine oxide and monensin.

It has been suggested that there are multiple pathways for the cellular internalization of insulin. To investigate these pathways we have examined the effects of three perturbations of endocytosis on the insulin internalization process and have compared these effects with those obtained using an asialoglycoprotein, asialofetuin (Afet), and epidermal growth factor (EGF). Freshly isolated hepatocytes were incubated with radiolabeled ligands and internalization measured under conditions of anoxia to deplete cellular ATP, in the presence of phenylarsine oxide (PAO) to inhibit endocytosis, and in the presence of monensin to interfere with endosomal acidification. Afet internalization essentially was blocked by all three treatment processes, while insulin internalization was inhibited approximately 40% in the presence of anoxia, and 54% in the presence of PAO. Monensin exhibited differential effects on internalization of high and low insulin concentrations. The effects of the treatment processes on EGF internalization were intermediate to those seen with Afet and insulin. These results suggest that insulin and EGF utilize routes of internalization exhibiting different energy requirements that may correspond to coated pit, non-coated pit, and fluid-phase internalization pathways. The observations with Afet internalization remain consistent with utilization of the coated pit pathway.

Adenosine Triphosphate↗
PubMed1993

Internalization of basic fibroblast growth factor (bFGF) in cultured endothelial cells: role of the low affinity heparin-like bFGF receptors.

We have shown (Presta et al., Cell Regul., 2:719-726, 1991) that a long-lasting interaction of basic fibroblast growth factor (bFGF) with endothelial GM 7373 cells is required to induce cell proliferation. In the present work, we have investigated the interaction of 125I-bFGF with GM 7373 cells, its pathway of internalization, and its intracellular fate under the same experimental conditions previously utilized to assess the mitogenic activity of the growth factor. Cell cultures were incubated with 10 ng/ml 125I-bFGF for 2 h at 4 degrees C. Then, cells were shifted to 37 degrees C without changing the medium. A rapid down-regulation of high affinity sites, paralleled by a rapid internalization of 125I-bFGF, was observed during the first 1-2 h at 37 degrees C. After 6-8 h, also low affinity sites down-regulate. This was paralleled by a continuous internalization of 125I-bFGF and by a slow disappearance of the growth factor from the culture medium. This suggests that GM 7373 cells activate, when exposed to bFGF for a long period of time, a late internalization pathway mediated by low affinity sites. This hypothesis was supported by the following experimental evidence: 1) soluble heparin inhibited the prolonged internalization of 125I-bFGF and its binding to low affinity sites with the same potency; 2) treatment of GM 7373 cells with heparinase, which removes most of the low affinity sites, also inhibited the prolonged internalization of 125I-bFGF. 125I-bFGF internalized via low affinity sites was partially protected from lysosomal degradation. This was the case also when 125I-bFGF was internalized in the presence of soluble heparin, suggesting that the complexes bFGF-cell surface glycosaminoglycan and bFGF-soluble heparin are maintained during the internalization of the growth factor. Moreover, the capacity of soluble heparin to inhibit the mitogenic activity of bFGF also when added to cell cultures several hours after the growth factor indicates that the requirement for a prolonged interaction of bFGF with GM 7373 cells in order to induce cell proliferation might be related to the late internalization of the growth factor via low affinity sites.

Animals↗
PubMed1994

Electromyography of the internal anal sphincter performed under endosonographic guidance. Description of a new method.

PURPOSE: The aim of our study was to investigate internal anal sphincter electromyographic signals. METHODS: Electromyography of the internal anal sphincter was performed with platinum wire electrodes in six healthy volunteers (three males and three females), inserted under endosonographic guidance. Platinum wire electrodes were also inserted into the external anal sphincter. Activity of both the internal and external and sphincter in a 40-second period was measured. RESULTS: Internal anal sphincter median activity was 22.1 (range, 5.5-67.6) microV. Slow-wave activity was 47 cycles/minute (range, 34-55 cycles/minute). After inflation of a rectal balloon with air until a constant relaxation of the anal canal was obtained, a decrease in internal and sphincter activity to 15.9 (1.2-31.3) microV as well as a decrease in slow-wave activity to 34 cycles/minute (range, 27-40 cycles/minute) was found. The original internal anal sphincter EMG was resumed after deflation of the rectal balloon. External anal sphincter median activity was 3.1 (range, 0.77-18.6) microV. During inflation of the rectal balloon, a reflex increase in external sphincter EMG activity was found. With the rectal balloon fully inflated a part of this increase was still present, 11.0 (1.9-24.6) microV. In some of the subjects, this increased activity was superimposed on the internal anal sphincter recordings as well. During a voluntary squeeze it was not possible to identify internal anal sphincter activity due to activity of the external anal sphincter totally overriding the internal anal sphincter signal. CONCLUSION: Precise EMG recordings from the internal anal sphincter is possible with endosonographic guidance of the electrodes, except during voluntary squeezing of the external and sphincter.

Adult↗
PubMed2006

Phlebographic classification of anatomic variants in the right internal spermatic vein confluence.

PURPOSE: Male varicocele is a clinical dysfunction caused by a pathological venous reflux. Knowledge of anatomic variants of the internal spermatic vein confluence is fundamental for the technical success of percutaneous treatment. While numerous studies have analysed the phlebographic anatomy of the left internal spermatic vein, no exhaustive description exists for the right internal spermatic vein. MATERIALS AND METHODS: From a retrospective review of 3229 patients treated percutaneously between 1988 and 2003, we extrapolated the phlebographic images of patients with incontinence of the right internal spermatic vein only. Mean patient age was 24.6 (range 14-46) years. Indication for treatment was presence of pain in the right inguinal region and absence of a history of trauma and/or seminal-fluid alterations. Phlebography had been performed with transbrachial access using a tilt table and a multipurpose angiographic catheter. Contrast medium was injected into both the inferior vena cava and the renal vein. Selective catheterisation of the internal spermatic vein was then performed to assess the radiological characteristics of the vessels prior to sclerosis. RESULTS: There were 93 cases of incontinence of the right internal spermatic vein only (2.8%). In the first group of patients (seven cases, 7.5%), the right internal spermatic vein drained exclusively into the renal vein; the injection of contrast medium during a Valsalva manoeuvre allowed visualisation of the vein almost as far as the iliac level. In most cases, the vein appeared uniformly dilatated and without valvular systems along its course. In the second group (21 cases, 22.5%), the vein drained into both the renal vein and the inferior vena cava, with one branch showing functional predominance over the other: selective catheterisation was easier to perform on the first branch. Selective catheterisation confirmed dilatation of the vein as well as the absence of valvular systems. In most patients, (65 cases, 69.8%), the internal spermatic vein drained into the inferior vena cava; the confluence was double in five patients and single in 60 patients. Visualisation of incontinence was limited to the initial 5-10 cm of the vein in 13 cases; however, vein dilatation and absence of valvular systems were confirmed beyond the semicontinent valve. CONCLUSIONS: Interventional treatment is one of the therapeutic options for male varicocele, but the method is limited by the presence of anatomic variants or aberrant supplying vessels, which make catheterisation and sclerosis of the internal spermatic vein difficult if not impossible. Interventional radiologists must have a thorough knowledge of anatomic variants of the right internal spermatic vein to be able to perform the procedure within a reasonable amount of time and reduce radiation exposure.

Adolescent↗
PubMed1991

Effects of galanin on the opossum internal anal sphincter: structure-activity relationship.

The present study was carried out to investigate the effects of porcine galanin-(1-29), N-terminal fragment galanin-(1-10), C-terminal fragment galanin-(15-29), and the middle fragment galanin-(7-16) on the spontaneous tension of the opossum internal anal sphincter and on the decrease in the resting internal anal sphincter tension in response to neural stimulation by electrical field stimulation. Galanin and galanin-(1-10) caused a concentration-dependent decrease in the resting tension of internal anal sphincter and an augmentation of the percent decrease in the resting tension with electrical field stimulation. Galanin-(15-29), on the other hand, produced an increase in the resting tension of the internal anal sphincter and had no effect on the electrical field stimulation-induced decrease in the resting tension. Galanin-(7-16) produced no significant effect on the internal anal sphincter. The decrease in the internal anal sphincter tension by galanin and galanin-(1-10) was partially antagonized by tetrodotoxin, whereas the increase in the internal anal sphincter tension caused by galanin-(15-29) was not modified by tetrodotoxin. In contrast to its effect in the internal anal sphincter, galanin caused an increase in the resting tension and suppressed a decrease in the lower esophageal sphincter tension in response to electrical field stimulation. From these findings we conclude that (a) galanin exerts an inhibitory effect on the internal anal sphincter by activating galanin receptors both at the intramural inhibitory neurons and at the internal anal sphincter smooth muscle and that the N-terminal portion of galanin may be responsible for these actions; (b) the contractile action of galanin is produced by its action on the smooth muscle; and (c) the actions of galanin on the gastrointestinal tract are tissue specific.

Anal Canal↗
PubMed1995

Internal thoracic artery grafts: 20-year clinical follow-up.

OBJECTIVES: This study compared the long-term clinical results of coronary artery bypass surgery in patients with internal thoracic artery grafts with those in patients with vein grafts only. BACKGROUND: Aortocoronary artery bypass surgery has been performed for > 25 years, primarily utilizing the saphenous vein and internal thoracic artery as conduits. Although the internal thoracic artery has been shown to confer a clinical advantage, it is not known for how many years this benefit will continue. METHODS: All consecutive patients undergoing initial coronary artery bypass surgery between 1970 and 1973 were followed for up to 20 years. Clinical evaluation included survival, late myocardial infarction, need for reoperation and recurrence of angina. Patients were analyzed in three groups: vein grafts only (214 patients); a single internal thoracic artery graft with or without associated vein grafts (490 patients); and bilateral internal thoracic artery grafts (39 patients). Use of the operating microscope was also analyzed with regard to effect on survival. RESULTS: The internal thoracic artery graft and use of the operating microscope were independent predictors of mortality and reduced the risk of dying by a factor of 0.68 and 0.76, respectively. An internal thoracic artery graft resulted in a mean survival of 4.4 years longer than that with vein grafts alone. The internal thoracic artery graft compared with vein grafts was associated with fewer reoperations (p < 0.001), fewer late myocardial infarctions, lower associated mortality rates (p < 0.04) and less early recurrence of angina (p = 0.03). CONCLUSIONS: The internal thoracic artery graft and use of the operating microscope confer a superior clinical advantage over the saphenous vein graft throughout a 20-year follow-up period. The advantage of an internal thoracic artery graft does not decrease with time, suggesting that the choice of conduit at the initial operation is more important clinically than progression of coronary artery disease.

Angina Pectoris↗
PubMed2005

Analysis of mGluR1a constitutive internalization using a pulse-chase enzyme-linked immuno-sorbant assay (ELISA).

The surface expression of G protein-coupled receptors is regulated by internalization. For many receptors, a constitutive level of internalization in the absence of agonist has been reported. The constitutive internalization of metabotropic glutamate receptor 1a (mGluR1a) has been described, but in general little attention has been dedicated to this important aspect of receptor regulation. Here we describe a pulse-chase ELISA method that allows the investigation of mGluR1a constitutive internalization. When investigated by pulse-chase ELISA, the constitutive internalization of mGluR1a was inhibited by dominant negative mutant constructs of arrestin-2 or Eps-15. This observation, besides indicating the arrestin- and clathrin-dependence of mGluR1a constitutive internalization, also confirmed the physiological relevance of the method described in this article. Confocal microscopy experiments to study receptor localization further validated the pulse-chase labelling procedure. The application of the pulse-chase ELISA to mGluR1b, revealed that this splice variant undergoes marginal constitutive internalization. Two COOH-terminal deletion mutants of mGluR1a, DMI (Arg847stop) and DMII (Arg868stop), were also tested for constitutive internalization. Interestingly, only DMII underwent significant constitutive internalization, suggesting that the region between Arg847 and Arg868 might play a regulatory role in mGluR1a trafficking. Taken together, the pulse-chase ELISA appears to be an efficient tool to analyze the constitutive internalization of different mGluR1 splice variants.

Alanine Transaminase↗
PubMed2005

Higher-order aberrations from the internal optics of the eye.

PURPOSE: To analyze the distribution of human higher-order wavefront aberrations (3rd- to 6th-order) from the internal optics (WA(internal)) and the variations with age and to evaluate the degree of compensation that the internal optics provide for anterior corneal aberrations (WA(cornea)). SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. METHODS: With assumption of a simple model for the eye, the WA(internal) were obtained by direct subtraction of the WA(cornea) from the ocular aberrations (WA(eye)). The WA(eye) were measured using the WaveScan system (Visx, Inc.), and the WA(cornea) were computed from the topographic data (Humphrey Atlas) using the CTView program (Sarver and Associates, Inc.). In 144 eyes of 114 normal patients (age 20 to 69 years), WA(internal) were calculated for a 6.0 mm pupil and a compensation factor (CF) was computed, with positive values representing compensation of WA(cornea) by WA(internal) and negative values indicating that the internal surfaces add aberrations to those of the cornea. RESULTS: There was wide individual variation in WA(internal). The mean coefficient for 4th-order spherical aberration (Z(4)(0)) was -0.145 microm +/-0.094 (SD) (95% confidence interval [CI], -0.160 to -0.130 microm); 95.1% of eyes had negative values. The mean root-mean-square value for HOAs was 0.334 +/- 0.096 microm (95% CI, 0.319 to 0.350 microm). Moderate to high correlations were found between the right and left eyes in HOAs, 4th-order and 6th-order spherical aberration coefficients (Z(4)(0) and Z(6)(0)). With increasing age, the HOAs did not change, whereas the negative coefficients for Z(4)(0) tended to become less negative. Only the term Z(4)(0) had a CF significantly correlated with increasing age (r=-0.338, P<.05 with Bonferroni correction). CONCLUSION: WA(internal) varied widely among patients, and a moderate to high degree of mirror symmetry existed between the right and left eyes. Internal surfaces compensated at least partially for the HOA and Z(4)(0) in most eyes, and this compensation decreased only mildly with increasing age.

Adult↗
PubMed2004

Effect of carbon dioxide insufflation on free internal thoracic artery flows: is it a vasodilator?

BACKGROUND: This study was conceived to evaluate the effect of carbon dioxide insufflation on free internal thoracic artery flows. METHODS: We studied 56 consecutive patients who underwent coronary artery bypass grafting in which the left internal thoracic artery was anastomosed to the left anterior descending artery. The first 26 consecutive internal thoracic arteries were harvested as a pedicled graft (group 1), and the next 30 consecutive internal thoracic arteries were dissected by using the carbon dioxide insufflation technique (group 2). The internal thoracic artery harvesting was performed by 2 experienced surgeons by using the same instrumentation and technique. First, free flows of the internal thoracic arteries were registered after distal cutting of the vessel in both groups. After the first measurements, diluted papaverine was sprayed on the internal thoracic artery pedicle only in group 1, and then second measurements were registered after 15 minutes in both groups. Hemodynamic parameters were recorded with each measurement. RESULTS: The first free flow measurement was significantly higher in the carbon dioxide-insufflated internal thoracic arteries (group 2, 60 +/- 32 mL/min; group 1, 28 +/- 19 mL/min; P <.05). Although the second free flow measurement of the carbon dioxide-insufflated group was higher than in group 1, the difference was not statistically significant (68 +/- 46 mL/min vs 53 +/- 32 mL/min; P =.53). CONCLUSIONS: Carbon dioxide insufflation of the internal thoracic artery is an efficient technique to increase the flow and seems to be safe, simple, and reliable. When the internal thoracic artery is harvested in a carbon dioxide-insufflated fashion, arterial spasm and reduced early flow may be avoided, even without vasodilator agents such as papaverine.

Carbon Dioxide↗
PubMed2006

Visual analog scale questionnaire to assess quality of life specific to each symptom of the International Prostate Symptom Score.

PURPOSE: We assessed patient quality of life specific to each of the 7 items on the International Prostate Symptom Score, as evaluated with a novel visual analog scale questionnaire. MATERIALS AND METHODS: A total of 246 male patients with a chief complaint of lower urinary tract symptom were asked to complete the International Prostate Symptom Score and visual analog scale questionnaires to assess bother or satisfaction regarding patient quality of life specific to each of the 7 items on the International Prostate Symptom Score. RESULTS: An item with the maximum visual analog scale measure matched the chief complaint in 169 patients (69%). In contrast, the chief complaint failed to match to an item with the most severe International Prostate Symptom Score in 104 patients (42%) (p = 0.012). Multiple regression analysis to define the best predictor of International Prostate Symptom Score quality of life score of the 14 items, including International Prostate Symptom Score and visual analog scale, revealed that the best predictor was the visual analog scale measure for nocturia (p = 0.0003), followed by visual analog scale measures for frequency (p = 0.0004) and incomplete emptying (p = 0.01). After alpha-blocker treatment improvement in the visual analog scale measure for the chief complaint correlated better with improvement in the International Prostate Symptom Score quality of life score than the change in International Prostate Symptom Score. The overall test-retest correlation for the visual analog scale questionnaire in 55 healthy elderly men and 44 patients with lower urinary tract symptoms was 0.772 and 0.742, respectively (p <0.00001). CONCLUSIONS: The novel visual analog scale measure of quality of life specific to each of the 7 items on the International Prostate Symptom Score has a significant impact on identifying the patient chief complaint as well as on patient specific quality of life. Our study supports the concomitant use of the International Prostate Symptom Score and visual analog scale questionnaires.

Aged↗
PubMed2005

Amplatzer Vascular Plug to occlude the internal iliac arteries in patients undergoing aortoiliac aneurysm repair.

PURPOSE: The purpose of this report is to evaluate the use of conventional coils and the Amplatzer Vascular Plug, a type of nitinol-based self-expanding device, to occlude the internal iliac artery in patients undergoing aortoiliac or common iliac aneurysm endograft repair, or both. METHODS: Between August and December 2004, in preparation for endograft repairs of aortoiliac or common iliac artery aneurysms, or both, at a community hospital system, five patients underwent the occlusion of the internal iliac artery with an Amplatzer Vascular Plug to prevent endoleak. During the preceding 12 months, the conventional coil embolization of the internal iliac artery was used for the same purpose in 10 patients. RESULTS: In five patients undergoing the Amplatzer Vascular Plug occlusion of the internal iliac artery, precise deployment at the origin of the artery was achieved. Complete and precise occlusion was confirmed angiographically, and only one device was used for each internal iliac artery. Two patients reported mild buttock claudication 2 weeks after occlusion, which resolved completely by 6 and 8 weeks, respectively. A type II endoleak from the inferior mesenteric artery developed in one patient. In the previous 10 patients, 11 internal iliac arteries were treated with conventional coils. Subsequent repeat coil embolization was required for three patients. The procedural complications in this second group included one case of coil embolization into the superficial femoral artery and one into the common iliac artery; both errant coils were retrieved successfully by endovascular techniques. An average of 7 +/- 3.4 (mode of 5) coils were used for each internal iliac artery. Three cases of buttock claudication occurred after the unilateral internal iliac artery occlusion in this group and did not resolve. No evidence of ischemic bowel, buttock necrosis, or sexual dysfunction was observed in either group. The estimated average cost to occlude one internal iliac artery was 375 dollars for Amplatzer Vascular Plugs and 3,500 dollars for conventional coils. CONCLUSIONS: The Amplatzer Vascular Plug allows for a cost-effective method to occlude the internal iliac artery in patients undergoing endograft repairs of aortoiliac aneurysms. The use of a single device with a precise placement at the origin of the artery minimizes cost and avoids ischemic complications.

Aged↗
PubMed2003

The role of c-Src in platelet-derived growth factor alpha receptor internalization.

We used two approaches to investigate the role of Src family kinases (SFKs) in ligand-stimulated internalization of the platelet-derived growth factor alpha receptor (alphaPDGFR). In cells that normally express SFKs, the internalization rate of the F72/74 mutant alphaPDGFR (which is unable to recruit or activate SFKs) was slower than that of the wild-type (WT) alphaPDGFR. When expressed in cells lacking SFKs (SYF cells), internalization of the WT and mutant receptors was indistinguishable, which indicated that there was not an inherent defect in the mutant receptor's ability to undergo ligand-driven internalization. The internalization difference between the WT and mutant receptors was seen again when c-Src was expressed in the SYF cells. Surprisingly, c-Src slowed the internalization of the mutant receptor but had little effect on WT receptor. We propose the following working hypothesis to explain these findings. In resting cells SFKs suppress internalization of the alphaPDGFR by phosphorylating a hypothetical protein X. This suppression is relieved when cells are exposed to PDGF because SFKs are recruited to the activated WT alphaPDGFR and thereby no longer actively phosphorylate protein X. The internalization of the mutant receptor is slow because it is unable to recruit SFKs and thereby fails to relieve the suppression of internalization. Our findings suggest a role for SFKs in regulating the permissiveness for internalization of the alphaPDGFR.

Animals↗
PubMed1996

Hard and soft tissue imaging of the temporomandibular joint 30 years after diagnosis of osteoarthrosis and internal derangement.

PURPOSE: This article describes the clinical and imaging findings in the temporomandibular joints (TMJs) of patients 30 years after the initial diagnosis of osteoarthrosis and internal derangement. PATIENTS AND METHODS: Fifty-five TMJs with a history of osteoarthrosis and internal derangement and 37 contralateral TMJs that were asymptomatic 30 years ago were examined in 46 former patients. To visualize degenerative changes of the bony parts of the TMJ, transpharyngeal and transcranial radiographs were made; to visualize disc position, sagittal T1-weighted magnetic resonance (MR) images were made. For comparison, 22 TMJs of an age-matched control group without complaints related to the masticatory system were similarly examined. RESULTS: Thirty years after the initial diagnosis of osteoarthrosis and internal derangement, clinical signs in former patients hardly differed from those of control subjects. radiographic signs were significantly more common and more severe in former patients. A high percentage of osteoarthrosis and internal derangement was seen on MRI in both TMJs with a history of osteoarthrosis and internal derangement and in the contralateral TMJs. It appeared that osteoarthrosis and internal derangement in the contralateral TMJs had developed asymptomatically in most cases. None of the patients had required treatment for the contralateral TMJ; only one fourth of the patients had noticed symptoms. In the control subjects, osteoarthrosis and internal derangement were infrequently seen. A significant correlation was found between disc position and the severity of radiographically detectable degenerative changes of the TMJ. CONCLUSIONS: It was concluded that 30 years after initial diagnosis there were few clinical signs of osteoarthrosis and internal derangement, although radiographic signs were extensive. Bilateral osteoarthrosis and internal derangement, with one symptomatic and one asymptomatic TMJ, is a common phenomenon. Moderate to severe radiographically detectable degenerative changes may be the only sign of an underlying internal derangement.

Adaptation, Physiological↗
PubMed1997

A guide to preventing deep insertion of the cannulation needle during catheterization of the internal jugular vein.

OBJECTIVE: Accidental puncture of the vertebral artery during the internal jugular vein cannulation produces lethal sequelae. To prevent this, the cannulation needle must not be inserted too deeply. However, there is no useful guide for the optimal length of insertion of the needle for accessing the internal jugular vein. The authors examined the length of the needle needed to reach the internal jugular vein with three different sizes of needle (16, 20, and 23 gauge). DESIGN: Prospective study. SETTING: An academic medical center. PARTICIPANTS: Patients undergoing cardiovascular surgeries. INTERVENTIONS: The cannulation of the internal jugular vein was performed through the right internal jugular vein by the high approach. The needle was slowly advanced, keeping constant negative pressure on the syringe at 45 degrees to the skin surface until blood was aspirated; if blood was not aspirated during insertion, the needle was slowly withdrawn until blood was aspirated. The distance to the internal jugular vein was assessed by calculating the entire length of needle minus the length of needle from the skin surface to the hub. MEASUREMENTS AND MAIN RESULTS: The mean distance to the internal jugular vein ranged from 15.0 to 21.5 mm, and the larger needle required the longer distance to the internal jugular vein. CONCLUSIONS: The results may be a useful guide to prevent too deep insertion of the needle during internal jugular vein catheterization, especially when teaching residents who have limited experience with internal jugular vein catheterization.

Catheterization, Central Venous↗
PubMedDate not supplied

Use of vertebral levels to measure presumed internal rotation at the shoulder: a radiographic analysis.

Internal rotation of the shoulder is frequently measured by noting the maximal vertebral level reached by the patient's thumb, but it is not at all certain that this maneuver is strictly measuring internal rotation. We analyzed this maneuver with computed tomographic scans of the shoulder in differing positions. We also analyzed extension of the glenohumeral joint and scapulothoracic articulation with scapular lateral radiographs. Finally, we used posteroanterior radiographs to analyze elbow flexion at the limits of internal rotation behind the back. We found that maximal internal rotation behind the back occurs in approximately a 2 : 1 ratio between the glenohumeral joint and the scapulothoracic articulation. However, the scapulothoracic articulation was more significant in placing the arm behind the back, whereas the glenohumeral joint performed most of the internal rotation in front of the body. The scapulothoracic articulation assists in this motion by both extension and internal rotation of the scapula on the thorax. The limits of internal rotation behind the back are reached with a significant contribution from elbow flexion. We conclude that measuring shoulder internal rotation by the maximal vertebral level reached by the patient's thumb greatly oversimplifies the concept of internal rotation and that limitations in this motion may not be strictly due to a loss of internal rotation at the glenohumeral joint.

Adult↗