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Biomedical subjects

T Panetta

Publications and source records attributed to T Panetta.

At least 19 recordsLinked to original sources
PubMed2001

Impaired venous hemodynamics in a minority of patients with chronic leg ulcers due to sickle cell anemia.

BACKGROUND: Chronic or recurrent leg ulceration occurs in 25% of sickle cell anemia patients, but not in the remaining 75%. Doppler studies of venous function were normal in 16 sickle cell anemia patients with leg ulcers. PATIENTS AND METHODS: Venous Duplex Ultrasound was used to study 33 sickle cell anemia patients with chronic leg ulcers. RESULTS: Six of the 33 patients had venous reflux in at least one leg. CONCLUSIONS: Venous insufficiency may contribute to the development of leg ulcers in a minority of sickle cell anemia patients. A minority of sickle cell anemia patients with chronic leg ulcers can be shown to have leg venous reflux by duplex ultrasound imaging.

Adult↗
PubMed1991

Platelet-activating factor and polyunsaturated fatty acids in cerebral ischemia or convulsions: intracellular PAF-binding sites and activation of a fos/jun/AP-1 transcriptional signaling system.

Platelet-activating factor (PAF) is a lipid mediator formed in the early response of the central nervous system to ischemia or convulsions. Free polyunsaturated fatty acids and arachidonic and docosahexaenoic acids are accumulated along with PAF. Antagonists of PAF have been found to improve cerebral blood flow and partially block the rise in free fatty acids, an effect that may arise by way of inhibition of PAF receptors or stimulation of the reacylation of free fatty acids released upon insult. Three intracellular PAF-binding sites have been identified in rat cerebral cortex. These very high-affinity binding sites are inhibited by PAF antagonists, with certain antagonists exhibiting specificity for a particular binding site. This specificity indicates heterogeneity in these binding sites. Ischemia or stimulation also leads to protooncogene transcriptional activation. Here, we discuss studies with cells in culture showing that PAF promotes transcriptional activation of immediate-early genes. PAF activates the transcription of the immediate-early genes fos and jun, whose gene products are regulators of the transcription of other genes. Transcription of fos is also activated by convulsion or ischemia in the central nervous system. The activation of these genes by PAF can be inhibited by PAF antagonists, and is apparently accomplished by way of an AP-1 transcription regulatory sequence in the promoter region of the target genes. Studies with deletion mutants show that PAF can also exert its activating properties by way of cyclic adenosine-3',5'-monophosphate-(cAMP) and Ca(2+)-responsive elements, and suggest that PAF is involved in an interconnected network of cell signaling that may coordinate short-term and long-term responses of cells to stimulus and injury.

Animals↗
PubMed1989

Obturator bypass with nonreversed translocated saphenous vein.

Obturator bypasses with nonreversed translocated saphenous veins were performed in two patients with femoral graft infections. There were no deaths, limb loss, or graft occlusions at two and one-half years of follow-up in the first case and one and one-half years of follow-up in the second case. The nonreversed translocated saphenous vein is a versatile graft that allows for extraanatomic autogenous reconstruction in the face of infection. In both cases, small-caliber distal saphenous veins precluded performing reversed saphenous vein grafts.

Blood Vessel Prosthesis↗
PubMed1989

Arachidonic acid metabolism and cerebral blood flow in the normal, ischemic, and reperfused gerbil brain. Inhibition of ischemia-reperfusion-induced cerebral injury by a platelet-activating factor antagonist (BN 52021).

Cerebral ischemia and ischemia-reperfusion induced cerebral injury results in the accumulation of free fatty acids and diacylglycerols as a result of increased activity of phospholipases A and C. We have evaluated the incorporation of 14C arachidonic acid into the whole brain and synaptoneurosomes, the effect of cerebral ischemia on 14C incorporation, and the effect of a PAF antagonist (BN 52021) on cerebral blood flow, free fatty acids, diacylglycerols, and polyphosphoinositides. Peak incorporation of 14C arachidonic acid into the whole brain and synaptoneurosomal fractions occurred 30 minutes following intraventricular injection. Peak incorporation into cerebellar synaptoneurosomal fractions was at 60 minutes following intraventricular injection. Turnover in phospholipid pools was similar in the whole brain and synaptoneurosomes (PI greater than PC greater than PE). Considering phosphatidylinositol content in the gerbil brain, the specific activity of 14C arachidonic acid was 22 times greater in PI than PC. Five minutes of bilateral carotid artery ligation resulted in decreased phosphatidylinositol and polyphosphoinositols. Bilateral carotid artery ligation resulted in systemic arterial hypertension, complete forebrain ischemia (CBF less than 7 ml/100 gm/min) and a 20% to 50% reduction in midbrain CBF. Reperfusion resulted in cerebral reactive hyperemia and systemic hypotension. BN 52021 inhibited the maturation of ischemia-reperfusion induced cerebral injury. Cerebral blood flow was improved. Free fatty acids were decreased, suggesting inhibition of phospholipase A activity. Decreased DAG pools with increased PIP2 pools suggest a possible coinhibition of phospholipase C.

Animals↗
PubMed1988

Nonreversed translocated saphenous vein bypass for arterial trauma.

Nonreversed translocated saphenous vein (NTSV) bypasses were performed for 17 acute arterial injuries. The technique involved controlling hemorrhage, inserting indwelling shunts, perfusing the harvested saphenous vein with papaverine solution, placing the vein in a nonreversed orientation over the shunt, performing valvulotomy under arterial pressure with a modified Mills' valvulotome and completing the distal anastomosis just before removing the shunt. Followup ranged from 2 to 36 months. There were no graft occlusions. The advantages of using NTSV graft for reconstruction of arterial injuries include autogenous reconstruction, reduced size discrepancy between graft and artery at both the proximal and distal anastomosis, improved hemodynamics when spasm compromises distal runoff, and increased vein utilization. NTSV provides increased versatility with both large and small vessel trauma and may improve patency rates.

Arteries↗
PubMed1987

Effects of a platelet activating factor antagonist (BN 52021) on free fatty acids, diacylglycerols, polyphosphoinositides and blood flow in the gerbil brain: inhibition of ischemia-reperfusion induced cerebral injury.

The effects of a platelet activating factor antagonist (BN 52021) on cerebral ischemia-reperfusion was studied in the gerbil. Following ten minutes of bilateral carotid artery ligation, gerbils were reperfused and injected intraperitoneally with either BN 52021 or vehicle-dimethylsulfoxide. Cerebral blood flow and systemic arterial pressure were monitored until 90 minutes of reperfusion. Free fatty acids, diacylglycerols and polyphosphoinositides were then analyzed in forebrains and midbrains. BN 52021 inhibited the maturation of ischemic injury. Cerebral blood flow increased following 60 to 90 minutes of reperfusion. Free fatty acid levels were reduced likely by inhibition of phospholipase A. Phospholipase activity may likely be decreased since there was a tendency to increase phosphatidylinositol-4',5'-bisphosphate and diacylglycerols in BN 52021-treated animals.

Animals↗
PubMed1987

Investigations of factors influencing the prognosis of colon cancer.

Six hundred sixty patients from Downstate and Hackensack Medical Centers were restaged and reviewed to establish correlations with survival using Cox's proportional hazards model. Age, sex, tumor size, and total nodes examined in patients with involved nodes did not correlate with survival. Tumor depth, number of involved nodes, and total nodes examined in patients with uninvolved nodes did correlate with survival. Patients with metastatic invasion into an adjacent organ with uninvolved nodes had an excellent 5 year survival rate compared with patients who had full-thickness invasion into the serosa with uninvolved nodes. These observations need to be confirmed. The relationship of some of these factors to currently used staging systems has also been discussed.

Colonic Neoplasms↗
PubMed1987

Tinnitus originating from an abnormal jugular bulb: treatment by jugular vein ligation.

Tinnitus and hearing loss can occur in patients with a high-riding abnormal jugular bulb. Jugular vein ligation in selected patients can cure tinnitus and reverse hearing loss. A 39-year-old woman reported a 4-year history of right-sided tinnitus of increasing intensity associated with a mild hearing loss. Extensive evaluation revealed only an enlarged right jugular bulb with dehiscence of the normal petrous bony septum between the bulb and the middle ear. The patient underwent ligation of the right internal jugular vein and noted immediate cessation of tinnitus and the return of normal hearing. Review of the literature suggests that jugular vein ligation is appropriate in selected cases of venous tinnitus.

Adult↗
PubMed1987

Intussusception following abdominal trauma.

We reviewed the charts of 21 patients on the Trauma Service who were operated on for intestinal obstruction for the years 1983 through 1985. Six (28.6%) of the 21 patients had intussusception as the cause of their obstruction post-laparotomy for trauma. All were males ages 17 to 25 years. The mechanisms of injury were gunshot wounds in three, stab wounds in two, and blunt trauma in one. Five patients were hypotensive on admission with systolic BP less than 70, and two patients received uncrossmatched blood preoperatively. Injuries at exploration included liver laceration (six patients), gastric perforation (two patients), and diaphragmatic lacerations, splenic laceration, renal injury, and ventricular injury, one each. No patient suffered small intestinal injuries and we cannot explain the occurrence of intussusception. Intussusception occurred in the first 8 postoperative days in four patients and at 21 days, and 10 months, in the remaining two. The diagnosis was made twice by CT scan preoperatively. Jejunojejunal intussusception was common (five patients), jejunoileal in one and ileocolic in one (who also had a jejunojejunal intussusception). All patients were treated with manual reduction alone and none recurred. There were no postoperative complications and all patients were discharged by the eighth postoperative day. Our study suggests that early postoperative obstruction is caused by intussusception with unexpected frequency in trauma patients, and can be diagnosed by CT scan in some cases. Treatment with operative reduction has an excellent prognosis.

Abdominal Injuries↗
PubMed1986

Arterial embolectomy: a 34-year experience with 400 cases.

A series of 400 peripheral arterial embolectomies performed in 326 patients over a 34-year period is presented. Operative mortality was 11.0 per cent overall and 10.0 per cent in patients after the introduction and use of Fogarty catheters. The plateau in mortality is related to the association with serious underlying cardiac disease. The amputation rate was 9.5 per cent, with a corresponding 90.5 per cent limb salvage rate. Cardiac disease was the most common cause of emboli and was responsible for the majority of deaths. Mortality was considerably higher in patients with aortic and iliac emboli and in patients with recent myocardial infarcts. Amputation rates were higher with femoral and popliteal emboli and correlated directly with the time delay from onset of symptoms to performance of embolectomy. Higher amputation rates in the second half of the series are related to liberalization of the indications for embolectomy. Prompt operative management of patients with peripheral arterial emboli remains the treatment of choice. Low mortality and amputation rates can be achieved with early embolectomy and routine use of heparin.

Adolescent↗
PubMed1986

Early open reduction and internal fixation of the disrupted pelvic ring.

Early open reduction and internal fixation (ORIF) of extremity fractures in patients with multiple injuries has been demonstrated to be safe, improve survival, and decrease the incidence of respiratory failure. Complications leading to abandonment of planned operative fixation and death in several patients with pelvic fractures led us to initiate a policy of early ORIF of the disrupted pelvic ring. Early ORIF of the pelvis was performed in 15 multiply injured patients between May 1984 and August 1985. Patients ranged in age from 13 to 79 years, their Hospital Trauma Index-ISS scores ranged from 14 to 68, and number of preoperative transfusions ranged from 0 to 42. Types of fractures were A-P compression, two, lateral compression, one, vertical shear, seven, complex, two, and acetabulum with ring disruption, three. All patients were resuscitated, transported in pneumatic antishock garments, and evaluated by abdominal and pelvic CT scan (in two patients following celiotomy). Preoperative angiograms to assess retroperitoneal hemorrhage in eight patients resulted in identification and control of significant bleeding in five. The mean time from injury to pelvic stabilization was 38 hours. Seven patients underwent ORIF within the first 24 hours. In most cases simultaneous anterior and posterior internal fixation was performed with the patient in the lateral decubitus position. Excluding associated procedures, operative time averaged 5.1 hours. Intra-operative transfusions averaged 4 units (range, 0-11). Rigid fixation was achieved in all patients. Most patients were out of bed by the third postoperative day. No patient developed respiratory failure. Two patients developed wound infections. Modification of our technique has avoided this complication in the latter part of this series.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Use of the contrast-enhanced CT enema in the management of penetrating trauma to the flank and back.

There have been few innovations in the management of penetrating trauma of the flank and back since that reported by Peck and Berne in 1981. During 1984-1985 our Trauma Service treated 119 patients with injuries in these areas. In 56 patients management was based on the results of the contrast-enhanced CT enema (CECTE), a computerized tomographic technique designed to delineate all of the retroperitoneal viscera by simultaneously opacifying the small bowel, duodenum, colon, GU tract, and major vessels. Specific radiographic findings were present on 44 scans. Twelve scans were negative. Six scans were considered indications for angiography because of the proximity of the identified missile wounds or their hematomas to major vascular structures. One of these arteriograms revealed a renal artery pseudoaneurysm which would otherwise have remained undiagnosed. In 30 cases the penetrating wounds were well delineated by CECTE, and their nature and location were considered appropriate for nonoperative management. None required subsequent exploration. In eight cases CECTE demonstrated that the wounds were located so as to place specific viscera at risk for significant injury, but no definite injury was identified. Five of these patients were successfully managed by further evaluation and close observation, two were explored, and one signed out of the hospital. No scan demonstrated extravasation from a hollow viscus. Overall, 52 of our 56 patients (92%) were successfully managed nonoperatively on the basis of the interpretation of their CECTE findings. CECTE can be useful in the management of stable patients with penetrating trauma to the back and flank by identifying the nature and location of the resulting retroperitoneal injuries.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1986

An analysis of 161 falls from a height: the 'jumper syndrome'.

Vertical deceleration injuries represent a distinct form of urban blunt trauma. We reviewed 161 adult patients, admitted over 36 months, who jumped or fell from a height of one to seven stories and survived emergency department resuscitation. Charts and radiographs were analyzed to identify common injuries, complications, and causes of death. Those who fell five or more stories had a mean ISS of 41, for a predicted survival of 50% but actual survival of 83%. Virtually all these patients had multiple fractures. Sixty per cent of them presented in shock, yet more than two thirds had angiographically demonstrated retroperitoneal hemorrhage as their major source of bleeding. Thirteen patients had significant intra-abdominal injuries, with only one associated with major hemorrhage. Utilizing early diagnostic peritoneal lavage, ten of 13 patients explored had a therapeutic laparotomy. Hollow viscus perforations accounted for about one half of the abdominal injuries, including three duodenal injuries. Conclusions. 1) Patients who present in shock after falls from height are much more likely to be bleeding from retroperitoneal than intraperitoneal sources. 2) Early tap and lavage followed by emergency angiography and transcatheter embolization is the treatment of choice in this group of patients. 3) Although these patients often have multiple complex injuries, the prognosis for long-term survival is good. Therefore, we advocate early aggressive operation stabilization of fractures to permit patient mobilization, facilitate pulmonary toilet and nursing care, and to decrease long-term disability.

Abdominal Injuries↗
PubMed1985

CT diagnosis of renal pedicle injury.

The CT findings in 6 renal vascular injuries were reviewed. The most specific observations in traumatic renal arterial thrombosis were nonexcretion, "rim" enhancement, and abrupt termination of an enhanced renal artery. Other signs of a disrupted renal vascular pedicle included central retroperitoneal hematoma associated with limited perinephric hematoma causing lateral displacement of the kidney. We conclude that CT allows differentiation of the causes of the absent or poor urographic nephrogram after trauma and may obviate the need for time-consuming angiography. CT should replace excretory urography for the evaluation of polytrauma, especially when the mechanism of injury is compatible with pedicle disruption.

Humans↗
PubMed1985

The management of arterial injuries caused by penetration of zone III of the neck.

Penetrating trauma of the neck has been divided into three anatomic locations. Zone III, the subject of this paper, is defined as the area between the base of the skull and the lower border of the mandible. Management of these injuries remains problematic. Clinical assessment may be misleading, exploration may damage surrounding neurovascular structures, and injuries may go undetected. This has led us and others to advocate mandatory angiography before any surgical exploration. This report reviews 46 patients with Zone III injuries with respect to types of injuries, therapy and outcome. Angiography was normal in 22 patients who were treated conservatively with no complications. The remaining 24 patients sustained 39 arterial injuries diagnosed by contrast studies. Eighteen internal carotid injuries were identified in 16 patients. At operation ligation was performed in four patients and revascularization in two patients. One of the repairs subsequently thrombosed. Ten patients were managed nonoperatively by observation (seven patients) or angiographic embolization (three patients). Catheter embolization of the external carotid or its branches was performed to control bleeding (eight vessels) or close arteriovenous fistulas (two patients). Seven nonbleeding external vessels were successfully managed by observation. Two vertebral artery injuries were diagnosed. One required proximal embolization and distal ligation via occipital craniectomy to control a fistula between the vertebral artery and the jugular vein. Overall mortality was 8.6%. Three of the four deaths were in patients with neurologic deficit on admission. Another died of respiratory arrest. An air embolism resulting in hemiparesis was the only complication of the angiographic studies. We conclude that angiography is essential in Zone III neck wounds. It facilitates triage decisions and, combined with transcatheter embolization, enables the majority of these injuries to be managed without surgical exploration.

Adolescent↗
PubMed1985

The diagnostic superiority of computerized tomography.

One hundred three patients with blunt abdominal trauma were studied using computerized tomography (CT). By protocol CT was performed in hemodynamically stable adults either: before tap and lavage (T&L)--32 patients; after 'negative' (less than 20,000 RBC/mm3) or 'borderline' (20,000-50,000 RBC/mm3) lavage--28 patients; or to evaluate hematuria--43 patients. CT was performed after administration of oral and intravenous contrast. A comparison of T&L and CT was made in 60 patients. 16 of 42 patients with negative lavage had 22 injuries identified by CT. One of these patients with bilateral renal artery transection, mesenteric and pararenal hematomas died of a closed head injury. Six of 14 patients with borderline lavage results had nine injuries found on CT, including two with actively bleeding spleens confirmed at operation or angiography. One patient with a large retroperitoneal hematoma underwent successful control of hemorrhage by embolization. Only one injury, a paranephric hematoma found at operation was not identified preoperatively by CT. Seventeen of 85 patients with hematuria had GU abnormalities identified by CT. Findings included seven intrarenal hematomas or contusions, three fractures, three major renovascular injuries, four para- and six perinephric hematomas, and three collection system injuries with extravasation. The majority of these injuries were found in patients with more than 50 RBC/HPF; however, six of 47 patients with less than 20 RBC/HPF had abnormalities including a retroperitoneal bladder perforation and a renal mass (hypernephroma). Two bladder perforations and one urethral injury were identified by CT cystogram. Abdominal CT is more sensitive and specific than T&L or IVP.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1985

Percutaneous transcatheter embolization for arterial trauma.

With increasing technologic advances in interventional radiology, the vascular surgeon should be well versed in the indications, limitations, complications, and results of percutaneous transcatheter embolization for arterial trauma. Three hundred twenty-eight angiographically determined arterial injuries occurred in 242 patients from 1977 to 1984 in a major city hospital trauma center and were studied prospectively. Transcatheter embolizations performed for 107 arterial injuries in 100 patients were successful in 82.2% of injuries. Gelfoam, minicoils, microcoils, intimal dissections, or a combination of modalities was utilized. Anterior and posterior element pelvic fractures associated with hypotension and transfusion of 6 units or more of blood required embolization in 28 patients. Bleeding was controlled in 85.7% of patients. Percutaneous transcatheter embolization was also effective in controlling 84.2% of arteriovenous fistulas, 88.9% of penetrating neck arterial injuries, and 73.3% of postoperative intra-abdominal hemorrhage. Therapeutic transcatheter embolization is a valuable adjunct to the vascular surgeon dealing with the spectrum of vascular trauma.

Arteries↗