Biomedical subjects
Publications and source records attributed to C Sen.
Irreducible Galeazzi fracture-dislocation is a rare injury. Structures that mechanically block the reduction are usually soft tissues. We present an irreducible case due to distal ulnar intra-articular fracture.
In this retrospective study we evaluated the method of acute shortening and distraction osteogenesis for the treatment of tibial nonunion with bone loss in 17 patients with a mean age of 36 years (10 to 58). The mean bone loss was 5.6 cm (3 to 10). In infected cases, we performed the treatment in two stages. The mean follow-up time was 43.5 months (24 to 96). The mean time in external fixation was 8.0 months (4 to 13) and the mean external fixator index was 1.4 months/cm (1.1 to 1.8). There was no recurrence of infection. The bone evaluation results were excellent in 16 patients and good in one, while functional results were excellent in 15 and good in two. The complication rate was 1.2 per patient. We conclude that acute shortening and distraction osteogenesis is a safe, reliable and successful method for the treatment of tibial nonunion with bone loss, with a shorter period of treatment and lower rate of complication.
Activation of protein kinase-B/Akt (pAkt) is mediated by oestrogen and involves HER-2 in vitro, to phosphorylate Hdm2 and influence p53 cytoplasmic localisation and degradation. Expression of all active Akt isoforms (pAkt) were examined, together with p53/Hdm2 subcellular expression in invasive ductal breast cancers (IDCs), to evaluate whether in vitro findings were related to clinical data and determine the effect on outcome. Immunohistochemical expression of serine 473 specific phosphorylated Akt (pAkt) isoforms (Akt-1,2,3) was evaluated in 97 patients, together with subcellular expression of p53/Hdm2. The results show that pAkt was evaluable in 95 patients with cytoplasmic expression in 81% and more likely to be associated with larger tumours (P=0.007), with no correlation with HER-2 expression. pAkt correlated with increasing levels of cytoplasmic p53 (P=0.025) and was associated with a reduced disease-free survival (P=0.04; univariate). In conclusion, pAkt has implications in breast cancer growth through mechanisms inactivating p53 with an association with immunohistochemical p53 expression, which is preferentially cytoplasmic. Despite in vitro associations, pAkt appears to be a variable marker of HER-2 expression.
INTRODUCTION: p14ARF stabilises nuclear p53, with a variable expression of p14ARF mRNA in breast cancers. In vitro, nuclear p14ARF binds Hdm2 to block Hdm2-dependent nucleocytoplasmic shuttling of p53, which is required before cytoplasmic degradation of p53. p14ARF is negatively regulated by p53 and through p53-independent pathways. No studies have yet examined levels of p14ARF protein expression in breast cancer and their relationship to Hdm2/p53 immunoreactivity or subcellular localisation. Previously, immunohistochemical expression of cytoplasmic p14ARF, p53 and Hdm2 has been described. HER-2 (c-erbB2/neu) predicts prognosis and interacts with the p14ARF/Hdm2 pathway to inactivate p14ARF and to influence Hdm2 activity and localisation. This study examined p14ARF and p53/Hdm2 expression and subcellular localisation by using immunohistochemistry in a series of invasive ductal breast cancers (IDCs) with concomitant ductal carcinoma in situ (DCIS), to evaluate whether findings in vitro were related to clinicopathological parameters such as HER-2 and their effect on patient outcome. METHODS: The 4C6 anti-p14ARF monoclonal antibody and Dako Envision Plus system were used to evaluate p14ARF expression in 103 patients; p53/Hdm2 staining was performed. RESULTS: p14ARF was evaluable in 96 patients, with nuclear p14ARF expression (modified Quick-score > or = 3) in 79% (n = 76) of IDCs and in associated DCIS in 74 patients. Cytoplasmic p14ARF was detectable in 23 breast cancers. Nuclear and cytoplasmic p14ARF showed no correlation with p53 subcellular immunoreactivity. Increasing levels of cytoplasmic p14ARF were associated with nuclear and cytoplasmic Hdm2 expression (P < 0.001). Subcellular ARF expression was not associated with clinicopathological parameters, and although not an independent prognosticator, these preliminary findings suggest that cytoplasmic p14ARF might be associated with a better overall survival (P = 0.09; log rank). The association between HER-2 positivity and nuclear p14ARF (P = 0.038), as well as nuclear Hdm2 (P = 0.019), reflects the in vitro findings of HER-2 interaction with the ARF/Hdm2 pathway. Cytoplasmic p53 and Hdm2 expression might have biological implications, through an association of cytoplasmic p53 with increased tumour proliferation (P = 0.005), and an improved overall survival (P = 0.002, log rank) in cytoplasmic Hdm2-expressing tumours, that independently predict favourable overall survival (P = 0.02) and disease-free survival (P = 0.03). CONCLUSIONS: Nuclear p14ARF expression is similar in IDCs and DCIS and is associated with Hdm2 immunoreactivity. Nuclear p14ARF and Hdm2 might be regulated by HER-2. Clearly, our findings in vivo suggest a complexity of p14ARF/Hdm2 and p53 pathways in which consideration of cytoplasmic p14ARF and Hdm2 might have tumorigenic implications.
OBJECT: The authors analyze their experience with the treatment of 29 patients who underwent radical excision of skull base chordomas. METHODS: Modern skull base surgical techniques were used in all patients who were treated between August 1991 and July 2000. The degree of tumor resection was gauged according to intraoperative inspection and postoperative high-resolution imaging findings. There were 21 patients with primary disease and eight with recurrent disease. Total resection was accomplished in 18 patients. Five patients had undergone radiotherapy prior to the present surgery, and an additional eight patients underwent postoperative radiotherapy. There were no surgery-related deaths. In five patients who died of the disease, surgery and radiotherapy had failed to effect a cure. Two of the remaining patients are alive with recurrent disease, and there is questionable evidence of recurrence in another patient. All 24 patients are functioning independently. Cranial nerve impairment was the most common postoperative deficit, followed by cerebrospinal fluid (CSF) leakage and infection. CONCLUSIONS: The use of skull base techniques in radical surgery provides an opportunity to excise the tumor and the involved bone. In most cases the procedure-related cranial nerve deficits improve over time. The complications of CSF leakage and infection can be minimized and are preventable. Proton beam irradiation is an excellent adjuvant treatment but is reserved for patients with definite tumor recurrence or residual tumor that can be identified on the imaging studies.
Despite advances in neurological, reconstructive, and endoscopic sinus surgery, sphenoethmoid cerebrospinal fluid (CSF) fistulae continually pose difficult management problems. Standard surgical techniques for fistulae closure succeed approximately 78% to 90% of the time. To improve this success rate, hydroxyapatite cement (HAC), a Food and Drug Administration-approved substance for cranial defect repair, was applied to this problem in a clinical setting. Twenty-one patients with spontaneous, posttraumatic, or postoperative CSF leaks of the sphenoid sinus, cribriform plate, or ethmoid region were treated with HAC. Study participants were prospectively accrued at 5 tertiary care medical centers in the eastern United States. The CSF leaks of all 21 patients treated with HAC were successfully sealed by its initial application. The sites of CSF leakage included the nasal cavity (n = 2) and sphenoid sinus (n = 19). Fifteen of the patients had previously undergone a failed repair by standard methods. There have been no recurrent CSF leaks with a maximum follow-up of 72 months, and an average follow-up of 36 months. All patients have survived to date. The only HAC-related morbidity was the extrusion of the HAC when placed in the nasal cavity. Hydroxyapatite cement is an effective method of repair for postoperative, posttraumatic, and spontaneous sphenoid CSF leaks. The efficacy of HAC in sealing the CSF leak was unaffected by previous attempts at leak closure by standard methods or by its origin. Hydroxyapatite cement should not be applied transnasally for the treatment of an ethmoid region fistula owing to its high probability of extrusion. Correct patient selection and technical familiarity with HAC are necessary for successful application.
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OBJECTIVE: Orbital exenteration has long been the oncologic standard for malignant craniofacial lesions that invade the periorbita/orbit from adjacent locations. Although oncologically sound, this radical surgical procedure is cosmetically disfiguring for all patients. Most of the reconstructive options available are complex, requiring further surgery and/or expense. We herein introduce an alternative surgical technique for radical orbital surgery that spares the globe, thereby allowing an early, aesthetic appearance at a nominal cost. STUDY DESIGN AND SETTING: Twenty consecutive patients requiring an oncologic orbital exenteration and meeting the indications for the new procedure underwent surgery at a tertiary care medical center. Follow-up ranged from 1 to 6 years. RESULTS: Only 1 patient recurred in the orbit due to an error in patient selection. There was no surgical morbidity resulting from the globe-sparing technique itself. CONCLUSION: Globe-sparing orbital exenteration is a one-step, oncologically sound, aesthetically superior, low-cost alternative for those patients requiring radical orbital surgery and reconstruction.
The aim of the study is to demonstrate the ability of abnormal Doppler indices to predict the acid-base status of the fetus. A pulsed Doppler study of umbilical artery, middle cerebral artery and thoracic aorta were assessed on 30 intrauterine growth restricted and 27 appropriate-for-gestational-age fetuses immediately before cordocentesis. All the fetuses with absent end diastolic velocity in the umbilical artery were found to be acidemic by cordocentesis. Thoracic aorta pulsatility index (PI) increased and middle cerebral artery PI decreased significantly with increased umbilical impedance (r = 0.702, r = -0.340, respectively). Umbilical artery and thoracic aorta PI significantly increased, whereas middle cerebral artery PI decreased with a decrease in umbilical blood pH (r = -0.760, r = -0.642, r = 0.292, respectively). Doppler findings have a very strong correlation with the acid-base status of the fetuses. Increased umbilical impedance is associated with progressive impairment of placental gas exchange and that by the time diastolic flow is lost hypoxaemia or acidaemia is usually present.
OBJECTIVE: Our goals were to study the normal histological features of the jugular foramen, compare them with the histopathological features of glomus tumors involving the temporal bone, and thus provide insight into the surgical management of these tumors with respect to cranial nerve function. METHODS: Ten jugular foramen blocks were obtained from five human cadavers after removal of the brain. Microscopic studies of these blocks were performed, with particular attention to fibrous or bony compartmentalization of the jugular foramen, the relationships of the caudal cranial nerves to the jugular bulb/jugular vein and internal carotid artery, and the fascicular structures of the nerves. In addition, we studied the histopathological features of 11 glomus tumors involving the temporal bone (10 patients), with respect to nerve invasion, associated fibrosis, and carotid artery adventitial invasion. RESULTS: A dural septum separating the IXth cranial nerve from the fascicles of Cranial Nerves X and XI, at the intracranial opening, was noted. Only two specimens, however, had a septum (one bony and one fibrous) producing internal compartmentalization of the jugular foramen. The cranial nerves remained fasciculated within the foramen, with the vagus nerve containing multiple fascicles and the glossopharyngeal and accessory nerves containing one and two fascicles, respectively. All of these nerve fascicles lay medial to the superior jugular bulb, with the IXth cranial nerve located anteriorly and the XIth cranial nerve posteriorly. All nerve fascicles had separate connective tissue sheaths. A dense connective tissue sheath was always present between the IXth cranial nerve and the internal carotid artery, at the level of the carotid canal. The inferior petrosal sinus was present between the IXth and Xth cranial nerves, as single or multiple venous channels. The glomus tumors infiltrated between the cranial nerve fascicles and inside the perineurium. They also produced reactive fibrosis. In one patient, in whom the internal carotid artery was also excised, the tumor invaded the adventitia. CONCLUSION: Within the jugular foramen, the cranial nerves lie anteromedial to the jugular bulb and maintain a multifascicular histoarchitecture (particularly the Xth cranial nerve). Glomus tumors of the temporal bone can invade the cranial nerve fascicles, and infiltration of these nerves can occur despite normal function. In these situations, total resection may not be possible without sacrifice of these nerves.
OBJECTIVE: The objective of this study was to determine the utility and safety of rigid endoscopy as an adjunct during posterior fossa surgery to treat cranial neuropathies. METHODS: A suboccipital craniotomy was performed for 19 patients with non-neoplastic processes involving the Vth, VIIth, and/or VIIIth cranial nerves. Ten patients with trigeminal neuralgia (n = 8), hemifacial spasm (n = 1), or intractable tinnitus (n = 1) underwent primarily microvascular decompression procedures. One patient with geniculate neuralgia underwent nervus intermedius sectioning combined with microvascular decompression. Eight patients underwent unilateral vestibular nerve neurectomies for treatment of Meniere's disease. A 0- or 30-degree rigid endoscope was used in conjunction with the standard microscopic approach for all procedures. RESULTS: All patients experienced resolution or significant improvement of their preoperative symptoms after posterior fossa surgery. The endoscope allowed improved definition of anatomic neurovascular relationships without the need for significant cerebellar or brainstem retraction. Cleavage planes between the cochlear and vestibular nerves entering the internal auditory canal and sites of vascular compression could not be microscopically observed for several patients; however, endoscopic identification was possible for all patients. There were no complications related to the use of the endoscope. CONCLUSION: The rigid endoscope can be used safely during posterior fossa surgery to treat cranial neuropathies, and it allows improved observation of the cranial nerves, nerve cleavage planes, and vascular anatomic features without significant cerebellar or brainstem retraction.
Since the introduction of ultrasound scanning in early pregnancy, transabdominal or transvaginal ultrasonography has taken on an important role in routine clinical practice in terms of the care of the fetus and the mother. The use of ultrasound in very early pregnancy makes it possible to confirm the intrauterine living embryo or diagnose the extrauterine pregnancy in which medical treatment with low morbidity is feasible with early detection. Early scanning can provide exact dating with acceptable error, which is one of problems encountered in clinical practice. Chorionicity can be correctly established by early scanning (before 14 weeks of gestation) to manage multiple pregnancies properly. The nuchal translucency, which is a transitory abnormality, can be measured for the early screening of Down's syndrome, trisomy-18, trisomy-13, Turner's and some other aneuploidy at the 11-14 weeks gestation with approximately 80% detection rate. Early diagnosis of some major abnormalities such as anencephaly, megacystis, polycystic kidney, omphalocele is also possible by early scanning. This provides great advantages as the clinical management will be quite different for a case of omphalocele or megacystis. Therefore the early ultrasound scanning has become a routine standard method in the care of the pregnant woman.
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BACKGROUND: The search for the ideal dural replacement in the setting where autogenous tissues are unavailable or inadequate still persists. Because of the ability of acellular dermis (AlloDerm, LifeCell Corporation, The Woodlands, TX) to remodel itself into native tissue, this dynamic quality is hypothesized to occur when used as a dural replacement. METHODS: We report the long-term outcome of a small cohort of patients who, to our knowledge, were the first patients to receive AlloDerm for dural replacement. In addition, to put these current findings in a historical perspective, we present a review of the literature for dural replacement. RESULTS: Ten patients all successfully underwent duraplasty with AlloDerm with only one postoperative complication that was not related to the acellular dermal dural repair. CONCLUSIONS: We contend that AlloDerm is a safe and viable option for dural replacement in cases in which autogenous tissues are either unavailable or insufficient for proper reconstruction.
OBJECTIVE: To determine the efficacy and safety of quick-setting hydroxyapatite cement in eliminating cerebrospinal fluid (CSF) rhinorrhea following neurotologic surgery. STUDY DESIGN: A prospective study of 40 consecutive patients undergoing neurotologic surgery in whom the dura was opened. SETTING: All patients were treated as hospital inpatients at a tertiary referral center. PATIENTS: 25 men and 15 women between the ages of 20 and 72 years (mean age 51 years) underwent neurotologic surgery at the parent institution. INTERVENTION: Various neurotologic procedures were performed for the resection of 25 acoustic tumors, 5 meningiomas, 3 glomus tumors, 2 vestibular nerve sections, 2 chordomas, 1 epidermoid tumor, and 1 meningoencephelocele, and for 2 patients referred to our institution with known CSF leaks following acoustic tumor surgery. A new form of quick-setting hydroxyapatite cement, which that hardens within 3 to 5 minutes was used to seal the air cell tracts of the temporal bone in all cases. MAIN OUTCOME MEASURE: The presence of CSF rhinorrhea postoperatively. RESULTS: CSF rhinorrhea occurred in 2 patients following acoustic tumor surgery, the first through an occult air cell tract at the margin of the drilled internal auditory canal, and the second via an oval window fistula 1 month after a translabyrinthine approach. CONCLUSIONS: This form of hydroxyapatite cement appears safe, reliable, effective, and economical for the prevention of CSF rhinorrhea following neurotologic surgery. CSF rhinorrhea cannot be eliminated unless our ability to identify all potential air cell tract communications improves.
The outcome of referral to colposcopy of 240 women who had persistently inadequate smears was investigated. Of 232 women who attended colposcopy, 214 (92.2%) had a normal outcome, 12 (5.2%) had low grade abnormalities, and six (2.6%) had high grade abnormalities. This group of women therefore has a negligibly increased risk of harbouring cervical neoplasia. Although not directly comparable, women with a history of previous abnormal cytology did not have a higher risk than those without such a history. Unnecessary colposcopy could have been avoided in the majority of cases if a good quality repeat smear had been taken. Improved smear taker training could decrease the number of referrals. A hospital cytology clinic is proposed as a cost-effective alternative to colposcopy at the first attendance.
A variety of autogenous and synthetic materials have been used to repair cranial defects resulting from traumatic and iatrogenic causes. In theory, the ideal material should be readily available and safe. It should adequately protect the underlying central nervous system, resist cerebrospinal fluid fistula formation, and be easily contoured. One promising synthetic biomaterial that has been used for cranioplasty is hydroxyapatite cement. This biomaterial has successfully restored cranial contour in most patients in whom it has been used; however, difficulties have arisen because of the material's prolonged water solubility. When exposed to cerebrospinal fluid or blood, inadequate setting of the cement occurs, resulting in loss of its structural integrity. This problem can be alleviated with the use of fast-setting hydroxyapatite cement, which hardens 6 to 12 times faster than the traditional cement. We present, to the best of our knowledge, the first series of the use of this material in 21 patients requiring cranioplasty. The advantages and limitations of fast-setting hydroxyapatite cement will be discussed.
A standard reversed digital artery flap is based on the digital artery and vena comitantes alone, leaving the proper digital nerve intact. In the authors' opinion, in situations in which the fingertip pulp is lost completely, it is unnecessary to leave the nerve in situ. Using their technique, the proper digital nerve is included in the pedicle. The pedicle is raised as a monobloc of fatty tissue containing the small veins important for drainage. The proper digital nerve in the flap is sutured to the stump of the opposite proper digital nerve. They found this flap to be very reliable, and quite easy and quick to raise. A patient is presented and discussed in detail.