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Biomedical subjects

J J Guerra

Publications and source records attributed to J J Guerra.

At least 19 recordsLinked to original sources
PubMed1999

ACE inhibition scintigraphy in the management of hypertension in children.

Angiotensin converting enzyme (ACE) inhibition scintirenography was performed to help establish the diagnosis and plan treatment of renovascular hypertension (RVH) in 57 hypertensive pediatric patients, 33 infants and 24 children older than 1 year. In 16 of 33 hypertensive infants, ACE inhibition scintirenography established the diagnosis of RVH from renal ischemia (due to aortic or renal arterial thrombi). Two scintigraphic criteria were used for the diagnosis of RVH: criterion I, ischemic and damaged kidney (a non-functioning kidney on or off ACE inhibition) and criterion II, ischemic but not damaged kidney (ACE inhibition induced deterioration of function of the kidney). When criterion I was present and the contralateral kidney was normal, ACE inhibitors could be used for treatment of hypertension without deterioration of renal function; kidneys satisfying criterion I eventually involuted or manifested growth arrest and frequently caused persistent RVH, even after resolution of the thrombus, requiring nephrectomy. When criterion II was present bilaterally, or it was associated with criterion I contralaterally, the use of antihypertensive drugs other than ACE inhibitors was necessary in order to prevent renal insufficiency or failure from ACE inhibitors. However, kidneys with criterion II showed normal growth and, following retraction or dissolution of the aortic thrombus, hypertension resolved. In 2 of 24 hypertensive children older than 1 year, the test was diagnostic of branch renal artery stenosis; RVH was cured by selective angioplasty. ACE inhibition scintirenography is useful in the evaluation and planning of treatment in children with hypertension and may predict the outcome of therapy and ultimate renal function.

Adolescent↗
PubMed1999

A phase I study of chemoembolization with cisplatin, thiotepa, and lipiodol for primary and metastatic liver cancer.

Thirty patients with primary hepatocellular carcinoma or liver metastases were entered into a program of chemoembolization with cisplatin, lipiodol, and escalating doses of thiotepa. Doses of cisplatin were 100/m2, and thiotepa doses ranged from 9 mg/m2 to 24 mg/m2. Two of three patients with ocular melanoma had partial responses in the liver metastases for 3+ and 16 months. In patients with either hepatocellular carcinoma (15 patients) or primary cholangiocarcinoma of the liver (three patients), there were two partial responses, for 22 and 33 months. Five patients had minor responses: four with a 40% reduction in tumor and one with a mixed response. There were four early deaths, which involved sepsis in two patients, respiratory failure in one, and acute myocardial infarction in one. Otherwise, toxicity was tolerable and reversible and included abdominal pain and transient elevation of serum creatinine, bilirubin, and transaminases. Less common toxicities included ototoxicity and peripheral neuropathy. Chemoembolization of the liver with cisplatin, thiotepa, and lipiodol can produce responses, but toxicity can be significant. The recommended starting phase II dose for future studies is thiotepa 24 mg/m2 and cisplatin 100 mg/m2.

Adult↗
PubMed1998

Pictorial essay: thoracic cardiovascular complications of acquired immunodeficiency syndrome.

Patients with acquired immunodeficiency syndrome frequently develop complications of cardiac, pericardial, and thoracic vascular origin. The purpose of this pictorial essay is to review the most common etiologic and diagnostic imaging findings of these diseases. Patients with acquired immunodeficiency syndrome often demonstrate enlargement of the cardiac silhouette on the chest radiograph. While the cause of this finding may be clinically evident, the authors share cases in which chest computed tomography, echocardiography, and nuclear medicine studies better reveal the nature of underlying cardiac and pericardial abnormalities. Thoracic vascular complications, including pulmonary hypertension, pulmonary thromboembolism, and the sequelae of indwelling venous catheters, are also addressed.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Arthroscopically assisted placement of a supracondylar intramedullary nail: operative technique.

The use of retrograde interlocking intramedullary nails has been described for the treatment of selected supracondylar fractures. A medial parapatellar incision and arthrotomy with its attendant morbidity is generally used for nail placement. Although a closed technique of nail placement has been described, the risks of damaging intra-articular structures with a blind approach have precluded the widespread use of this method. In this article, we present a simple, arthroscopically assisted method for the retrograde intramedullary nailing of supracondylar femoral fractures. This technique affords the potential benefits of intramedullary fixation of these fractures while avoiding the morbidity and complications associated with an arthrotomy. Potential benefits over the standard placement using an arthrotomy include earlier ambulation and soft tissue healing, decreased risk of damage to the knee joint, earlier convalescence with decreased hospitalization time, and better cosmesis.

Adult↗
PubMed1995

Cost effectiveness of intraoperative autotransfusion in total hip arthroplasty surgery.

The purpose of this study was to analyze the cost effectiveness of the cell saver in reducing homologous blood transfusion requirements in patients undergoing primary total hip arthroplasties. In patients who had predonated autologous blood, the addition of the cell saver neither reduced the homologous blood requirements nor the percentage of patients exposed to banked blood. In patients without predonated autologous blood, the cell saver decreased the percentage of patients exposed to banked blood by 40% and decreased the mean homologous transfusion requirement from 2.6 to 1.5 units per patient (p < 0.05). The cell saver became cost effective when 3 units of blood were salvaged. Because the cell saver reclaimed a mean of 453 ml (approximately 2 units), it was not cost effective. This analysis is confounded by the risk of exposure to blood borne potentially life-threatening pathogens. In patients undergoing elective primary hip arthroplasty, the availability of predonated autologous blood obviates the need for expensive intraoperative blood salvage techniques. If an adequate volume of autologous blood cannot be procured preoperatively, or if the clinician suspects excessive intraoperative bleeding, then using the cell saver may be justified.

Blood Loss, Surgical↗
PubMed1994

A phase I study of chemoembolization with cisplatin and lipiodol for primary and metastatic liver cancer.

Twenty patients with either unresectable primary hepatocellular carcinoma or hepatic metastases were entered into a chemoembolization program with cisplatin and lipiodol; 19 patients were evaluable for response. Doses of cisplatin ranged from 40 to 100 mg/m2. Toxicity was tolerable and reversible and included abdominal pain, transient elevation in serum creatinine, serum bilirubin, and serum transaminases. Less common side effects include fever, ascites or pleural effusion, and hiccups. Two of four patients with ocular melanoma had partial responses. Duration of response was 10 and 11 months. Among 8 patients with unresectable hepatoma, 2 patients had partial response for 10+ and 13 months, 2 had minor response for 2 months and 4+ months, 1 patient had stable disease for 5+ months, and 3 patients failed to respond. Of the six colon cancer patients treated, one had a partial response in the liver, but developed progressive nodal disease, and another patient had a partial response for 3 months. Chemoembolization of the liver with cisplatin and lipiodol is feasible and doses of cisplatin at least 100 mg/m2 are tolerable. Antitumor activity in metastatic ocular melanoma is encouraging but requires further study.

Adult↗
PubMed1994

Characterization of a cell-type-restricted negative regulatory activity of the human granulocyte-macrophage colony-stimulating factor gene.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates the proliferation and maturation of normal myeloid progenitor cells and can also stimulate the growth of acute myelogenous leukemia (AML) blasts. GM-CSF is not normally produced by resting cells but is expressed by a variety of activated cells including T lymphocytes, macrophages, and certain cytokine-stimulated fibroblasts and endothelial cells. Production of GM-CSF by cultured AML cells has been demonstrated, and GM-CSF expression by normal myeloid progenitors has been postulated to play a role in myelopoiesis. We have investigated the regulation of expression of GM-CSF in AML cell lines, and our results demonstrate the presence of a strong constitutive promoter element contained within 53 bp upstream of the cap site. We have also identified a negative regulatory element located immediately upstream of the positive regulatory element (within 69 bp of the cap site) that is active in AML cell lines but not T cells or K562 CML cells. Competition transfection and mobility shift studies demonstrate that this activity correlates with binding of a 45-kDa protein.

Base Sequence↗
PubMed1994

Fatal massive hemoptysis secondary to intralobar sequestration.

We report the case of a 29-year-old woman who died of massive hemoptysis due to hemorrhage from an intralobar pulmonary sequestration into the tracheobronchial tree. The sequestration had been diagnosed in childhood but had been managed nonoperatively. This case emphasizes the need for early surgical treatment of pulmonary sequestration.

Acute Disease↗
PubMed1994

Equipment malfunction in common hand surgical procedures. Complications associated with the pneumatic tourniquet and with the application of casts and splints.

Pneumatic tourniquets and plaster of Paris splints and casts are the hallmarks of hand surgery, firmly entrenched as an adjunct in the routine treatment of upper extremity disorders. Because they are usually employed with a comparative degree of safety and because they are relatively simple devices from a technologic perspective. Little is written about them in the scientific literature. In this paper we extensively review their historical developments, physiologic effects, and common complications, and we attempt to provide a rationale for their safe and effective use.

Burns↗
PubMed1990

CT appearance of uterine leiomyomas.

Uterine leiomyomas, commonly known as fibroids, are one of the most common pelvic tumors found in women. Ultrasonography is the primary modality for evaluating leiomyomas. However, frequently these tumors are not accompanied by symptoms, and they are found incidentally during computed tomographic (CT) examinations performed for other indications. Because leiomyomas may first be noted on CT scans, radiologists should become familiar with their characteristic appearance. The authors describe the CT findings of uterine leiomyomas and their secondary changes, including cystic degeneration, calcification, infection, necrosis, fatty degeneration, and sarcomatous degeneration.

Calcinosis↗
PubMed1990

Left hepatic duct anatomy: implications.

A review of the findings of a 10-year experience with biliary interventional procedures in 838 patients led to consideration of the anatomy of the left hepatic duct. To better illustrate the findings, 15 normal human livers obtained at autopsy were fixed and dissected. Fifty-five percent of the patients had a single left hepatic duct that was formed by the intrahepatic union of ducts draining segments II and III (segmental nomenclature follows Couinaud) lateral to the falciform ligament. Central to this ligament, the left duct became extrahepatic and was joined by ducts from segments I and IV. The real and theoretical implications of the unpredictable variability of biliary anatomy, the frequency of right lateral duct drainage into the left hepatic duct, and the extrahepatic contiguous relationship between the left hepatic duct and the left portal vein are discussed.

Bile Ducts, Intrahepatic↗
PubMed1986

Percutaneous biliary drainage in acute suppurative cholangitis.

One hundred and sixteen percutaneous drainage procedures of the biliary system were performed in a 2-year period. Eight of 9 acutely ill patients with the diagnosis of acute suppurative cholangitis were successfully treated nonoperatively. They represented 26% of all patients with benign or postsurgical obstruction referred for biliary decompression. Conversely, acute suppurative cholangitis only occurred in 2.3% of patients with underlying malignant disease. These observations are considered most relevant in predicting the purulent nature of the disease, with further implications for patient management. Early recognition and prompt decompression of the biliary system are mandatory, along with the appropriate antibiotic coverage. Our experience compares favorably with surgical results and the procedure is proposed as the method of choice for the initial treatment of acute suppurative cholangitis.

Acute Disease↗
PubMed1985

Transgastric drainage of pancreatic fluid collections.

Eight pancreatic fluid collections in seven patients were successfully drained percutaneously through a transgastric approach. The drainage catheters were left in place for 3-6 weeks to promote the formation of a fistulous tract between the stomach and the pancreatic collection. Computed tomography (CT) was used for diagnosis and for planning of the access route. Combined sonography and fluoroscopy were used for guidance. Radiologic follow-up examinations (CT and sinograms) have shown no recurrences (3-12 months). No complications were encountered.

Drainage↗
PubMed1984

Abandonment of endoprosthetic drainage technique in malignant biliary obstruction.

This report discusses a 3-year experience with the techniques of internal/external catheter and endoprosthetic stent drainage in 175 patients with obstructive jaundice. In 166 patients, the obstruction was bypassed satisfactorily. The complications encountered with these techniques are compared, and the radiation doses involved are emphasized. It is not necessary to put patients through the extra time and pain related to the placement of the endoprosthesis, because internal/external catheter placement produces the same desired result of biliary decompression without the higher radiation doses to the radiologist.

Adolescent↗