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Biomedical subjects

J Guerra

Publications and source records attributed to J Guerra.

At least 55 records · Page 3Linked to original sources
PubMed1988

Absence of infection with human immunodeficiency virus in Peruvian prostitutes.

We serologically tested 140 female prostitutes (mean age, 30 years) from the port city of Callao, Peru, for evidence of infection with human immunodeficiency virus (HIV), Chlamydia trachomatis, Treponema pallidum, herpes simplex viruses (HSV) I and II, and hepatitis B virus. The women had worked as prostitutes for an average of 5 years; one-fourth serviced foreign visitors exclusively, mainly sailors. Only 4 women used condoms, and only 1 woman gave a history of parenteral narcotic abuse, although 53% were regularly exposed to unsterile needles outside the medical setting for injections of vitamins, antibiotics, or steroids; another 29% are thought to probably use unsterile needles. None of the 140 prostitutes screened was seropositive for HIV, despite a very high prevalence of antibody to T. pallidum (24%), C. trachomatis (97%), HSV I and II (100%), and hepatitis B (51%); 5% were HbsAg positive. These data indicate that HIV has not yet been introduced into female prostitutes in the Peruvian port city. We believe that widespread use of unsterile needles in developing countries, such as Peru, represents a serious health threat and will amplify the spread of HIV, once introduced.

Adolescent↗
PubMed1986

Computerized tomography of proximal femoral trabecular patterns.

A comprehensive imaging and pathologic investigation utilizing patients and cadaver material was performed in order to identify the normal trabecular pattern of the proximal femur and to assess alterations in this pattern in various disorders. Patients and specimens were studied with computed tomography (CT), including three-dimensional CT image reconstruction in selected cases and plain film radiography. The CT imaging of the proximal femur provides insight into the dynamic state of bone in this region. Despite limited resolution, three-dimensional CT image reconstruction is capable of portraying the concentration and orientation of major trabeculae in the proximal femur. Increased trabecular spacing occurs in osteoporosis and is well depicted by CT. Proliferation and thickening of the most superior subchondral primary compressive trabeculae is an early sign of osteoarthritis. In the region of the calcar femorale, crossing trabeculae, similar to the appearance of an enchondroma or bone infarct, have been described in osteoporosis and osteoarthritis and probably represent unmasking of normally present reinforcing trabeculae. In ischemic necrosis, CT should be considered a useful modality for detection of early or mild alterations and may be valuable in treatment planning.

Cadaver↗
PubMed1986

An evaluation of diagnostic methods for brucellosis--the value of bone marrow culture.

Fifty patients, eventually diagnosed as having brucellosis, were studied prospectively for comparison of a simple culture of bone marrow aspirate from the iliac crest (0.5-1.0 ml) with two cultures of blood (5-10 ml) taken 30-60 min apart and with a tube-agglutination test. Cultures of bone marrow and blood were positive in 92% and 70% of the patients, respectively (P less than .001). Bacteria multiplied significantly faster in bone marrow cultures (4.32 vs. 6.65 days; P less than .001). All isolates were identified as Brucella melitensis biotype 1. Serological diagnosis was established in 86% of the patients. The efficacy of cultures of blood decreased significantly with chronic and subacute forms of infection, whereas that of bone marrow culture decreased only in chronic forms. Prior use of antibiotics reduced the positivity of cultures of blood but did not affect bone marrow culture. Bone marrow culture is recommended for patients with fever of unknown origin, negative serology, and unexplained articular or hematologic involvement, and patients in whom brucellosis is suspected.

Adolescent↗
PubMed1986

Perfluoroctylbromide as a contrast agent for computed tomographic imaging of septic and aseptic arthritis.

Perfluoroctylbromide (PFOB), a perfluorocarbon macrophage-labeling contrast agent, was applied to computed tomographic imaging of septic and aseptic arthritis models in rabbits. Marked enhancement of induced pyarthrosis was observed in both the knee and the sacroiliac joint. Moderate enhancement was noted in tetracycline-induced synovitis of the knee. Sterile synovitis of the sacroiliac joint and simple knee joint effusion showed no enhancement. These results suggest that PFOB is a useful contrast medium for the diagnosis of and distinction between septic and sterile arthritis.

Animals↗
PubMed1986

Regional isolated limb perfusion of melanoma intransit metastases using mechlorethamine (nitrogen mustard).

Forty-two patients with intransit metastases of melanoma in a limb were treated by isolated regional perfusion chemotherapy using mechlorethamine (nitrogen mustard). Group 1 (n = 12) underwent treatment at low dose, less than 0.35 mg/kg, or low temperature, less than 38 degrees C. Group 2 (n = 30) received higher doses, 0.35 to 0.6 mg/kg, plus heat at 38 degrees C to 41 degrees C. No patient had evidence of disease outside the limb at the time of perfusion. The median follow-up time was 48 months (range, 1 to 9 years). Of the 42 patients, 29 had measurable lesions that responded as follows: group 1, complete response (CR) in two of ten and partial response (PR) in none; group 2, CR in six of 19 and PR in six of 19. The combined CR and PR rate of 12 of 19 in group 2 was significantly higher than that of group 1 (P less than .05). CR lasted only 2 months in the two patients of group 1, but persisted in the six patients of Group 2, four of whom are still alive free of disease at 16, 21, 33, and 40 months. Relapse-free control of disease in the limb was achieved in 36% of the patients in group 2 at 24 months, compared with 0% in group 1 (P less than .05). An overall survival of 74% at 48 months was observed in group 2, significantly higher than that of 64% for group 1 (P less than .05). The status of the regional lymph nodes (RLN) and the number of metastases did not affect tumor response. However, 77% of RLN-negative patients survived 48 months, in contrast to only 38% of RLN-positive patients (P less than .05). One patient died postoperatively of myocardial infarction. No serious systemic toxicity developed. Two patients who underwent repeat salvage perfusions developed a reversible peripheral neuropathy in the limb. Limb function was good after treatment, and dramatically improved in patients who had advanced satellitosis that responded to treatment. These results suggest that heated limb perfusion using mechlorethamine at an adequate dose can offer long-term control of intransit metastases in approximately one third of these patients, with preservation of good limb function and possible prolongation of survival.

Adult↗
PubMed1985

The skeletal manifestations of clubbing: a study in patients with cyanotic congenital heart disease and hypertrophic osteoarthropathy.

The skeletal manifestations of clubbing of the digits have been occasionally noted and only briefly discussed in the literature. We investigated the radiographic features of digital clubbing in 37 patients with diverse diseases including cyanotic congenital heart disease, lung malignancy-associated hypertrophic osteoarthropathy, and idiopathic cases. We identified two types of bone changes--osteolysis or bone dissolution, and bone formation or hypertrophy. The changes were more evident in the feet than in the hands, and the degree of soft tissue change did not always reflect the underlying osseous abnormalities. The relationship of these changes (ie, osteolysis, hypertrophy) to each other appear to depend in part on the underlying disease as well as the time course or disease duration. Thus, clubbing and hypertrophic osteoarthropathy may not represent distinct entities; our data suggest that they may be stages in an evolving, more generalized process of new bone formation or hypertrophy followed by osteolysis or atrophy affecting many parts of the skeleton.

Adolescent↗
PubMed1985

Computed tomography demonstration of retroperitoneal contrast material extravasation complicating translumbar aortography.

The computed tomography appearance of contrast material extravasated in the right perirenal space is presented. The complication occurred during test injection prior to translumbar aortography. The computed tomography findings were those of a right prerenal collection with high attenuation numbers representing contrast extravasation. Concurrent displacement of the second portion of the duodenum and inferior vena cava was present. No other retroperitoneal abnormalities were noted. The importance of computed tomography for early recognition and follow-up are emphasized.

Aged↗
PubMed1985

Confirmation of the posterolateral technique to decompress and fuse thoracolumbar spine burst fractures.

A posterolateral technique to decompress retropulsed bone from the spinal canal has been employed in nine patients, confirmed with intraoperative canal inspection and pre- and postoperative computed axial tomographic (CAT) evaluation. This technique has allowed reduction of retropulsed bony elements from the spinal canal, assessment of canal decompression and reestablishment of vertebral body alignment. The approach permits posterior fusion at the same operation. If the postoperative CAT scan continues to show spinal cord embarrassment from anterior bony elements, an anterior approach can be performed for additional decompression and fusion. The posterolateral approach does not necessarily improve neurologic function. However, when compared with posterior instrumentation alone, it does help ensure canal reduction and alignment, which may aid recovery and hasten rehabilitation.

Adolescent↗
PubMed1985

Vertebral venous channels: CT appearance and differential considerations.

A comprehensive study of the anatomy, radiologic images, and pathology of venous channels in the thoracic and lumbar vertebral bodies was performed using cadavers and patients. These structures may be mistaken for fractures, lytic lesions, or other abnormalities on high-resolution axial computed tomographic (CT) scans of the spine. A distinct osseous wall, absence of extension over multiple contiguous levels, lack of displacement, and predominant localization in the mid-axial plane of the vertebral body are characteristic features of venous channels. An understanding of the normal intraosseous venous anatomy should prevent misinterpretation of clinical CT studies in most instances.

Diagnosis, Differential↗
PubMed1984

Diagnosis of typhoid fever using a string capsule device.

Cultures were made from blood, bone marrow, stool and duodenal contents (obtained with string capsules) from 36 patients with bacteriologically proven typhoid fever on admission to hospital. Duodenal content cultures proved to be as sensitive in diagnosis (86%) as bone marrow (75%) and more effective than blood (42%) and stool (26%) cultures in recovery of Salmonella typhi. The sensitivity of duodenal content cultures was not modified by the duration of illness at admission or by previous antibacterial therapy. Even on the seventh day of effective treatment with chloramphenicol, the culture of duodenal contents remained positive in 8 of 17 patients, whereas salmonellae were isolated from stool cultures in only 2 of the same patients. The results obtained with the string capsule, together with the simplicity, economy and acceptability of the procedure, the fact that it can be performed with minimal facilities and the advantages of bacteriological recovery for antibiotic sensitivity testing, suggest that its adoption would be very helpful in efforts to control this disease.

Bacteriological Techniques↗
PubMed1984

Replantation of digits or hands followed by destructive joint disease.

The clinical records and radiographs of 45 patients who had undergone replantation of a total hand, or a part thereof, were reviewed in order to determine the prevalence and the type of articular changes occurring distal to the site of anastomoses. In three patients, destructive joint changes were observed, consisting of bony fragmentation, spiculation, and cystic or erosive lesions. These changes, which developed between five and ten months after replantation, are most likely neuropathic or osteonecrotic in pathogenesis.

Adult↗
PubMed1984

Computed and conventional arthrotomography of the glenohumeral joint: normal anatomy and clinical experience.

The glenohumeral joint was studied in 25 cadavers and 136 patients using computed arthrotomography (CAT) and conventional arthrotomography (AT) to assess shoulder instability. Cadaver shoulders were injected with air or latex, sectioned with a band saw, and normal articular anatomy outlined. CAT was performed in 81 patients and characterized the glenoid labrum as normal, abnormal, or detached in 38 of the 44 patients who had surgery or arthroscopy (sensitivity, 96%; accuracy, 86%). Hill-Sachs defects were seen in 20 out of 29 patients with anterior labral abnormalities, while bicipital tendon abnormalities were evident on CAT in 6. Of 55 patients who had AT, the status of the labrum was clarified in 13 of the 16 patients who had surgery or arthroscopy (sensitivity, 86%; accuracy, 81%). Both methods can characterize the labrum; however, CAT is more comprehensive and appears ideal for both detection of Hill-Sachs defects and imaging the bicipital tendon. CAT requires less technical expertise and radiation than AT and is tolerated better by patients in pain.

Adolescent↗
PubMed1984

Vertebral burst fractures: CT analysis of the retropulsed fragment.

Ten cases of retropulsed thoracolumbar vertebral body fragments that had been documented by CT were reviewed to define and characterize the nature, appearance, and position of the retropulsed fragment. All of the retropulsed fragments arose from the superior aspect of the vertebral body. Five of ten patients had a vertical fracture within the retropulsed fragment. Three of ten fragments had anteriorly rotated 90 degrees +/- 60 degrees, so that the cartilaginous end plate faced anteriorly; also, they had migrated 3-8 mm in a craniad or caudad direction. Six of ten patients had an associated vertical or Y-shaped fracture originating from the region of the basivertebral foramen and passing into the inferior one-half of the vertebral body. The presence of a retropulsed fragment is nearly pathognomonic of an axial compression injury. Characteristics of this lesion that may hinder surgical reduction are the intra-fragment fracture, rotation, and craniocaudad movement.

Humans↗
PubMed1984

Digital arthrography of the wrist: a radiographic-pathologic investigation.

An analysis of digital arthrography of the wrist was accomplished in 10 cadaveric specimens. In each case, images were obtained during a 30-sec period in which a small amount of contrast material was introduced into the radiocarpal compartment; films were reviewed with and without subtraction technique. Pathologic examination of the sectioned specimens documented the accuracy of this arthrographic method. The sequence of contrast opacification of the various compartments of the wrist and the location and size of the defects within ligamentous and cartilaginous structures were ideally seen with digital arthrography. A previously unemphasized pattern of communication, that between the midcarpal and pisiform-triquetral compartments, was seen in two instances. Digital wrist arthrography seems to represent an excellent method to evaluate the patient with suspected soft-tissue injury.

Fluoroscopy↗