Biomedical subjects
Publications and source records attributed to J A Robb.
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Differentiation of occult skeletal injuries from early acute osteomyelitis in infants and young children is important clinically. The Tc-99m MDP scintigraphic findings in six patients who had occult femoral or tibial fractures were reviewed. The images obtained early (at 1-4 days from the onset of symptoms) shared the common characteristic finding of a subtle but definite, generalized increased uptake of the tracer along the entire length of the injured bone. This pattern of uptake was similar regardless of the type of fracture. These were different from the focal abnormalities that have been observed in early acute osteomyelitis. In the absence of an extensive cellulitis or a vascular occlusive disease, a bone image showing a mild diffuse uniform increased uptake along the entire length of the tibia or femur in infants and young children with lower extremity pain of less than 1 week's duration should suggest the diagnosis of occult skeletal fractures.
In an effort to delineate the distribution of the Leu-7 antigen in small cell neoplasms, 283 paraffin-embedded examples of such tumors were studied immunohistochemically. These included 125 malignant lymphomas, 94 neuroendocrine carcinomas, 13 adenocarcinomas, 14 squamous carcinomas, four malignant melanomas, six neuroblastomas, four nephroblastomas (Wilms' tumors), six primitive neuroectodermal neoplasms, three "Askin" tumors, ten Ewing's sarcomas, and four embryonal rhabdomyosarcomas. Histologic diagnoses were verified by the use of electron microscopic study or independent immunostains. Overall, 44% of small cell neuroendocrine carcinomas expressed Leu-7, whereas nonendocrine carcinomas were uniformly nonreactive for this determinant. All neuroblastomas yielded immunopositivity, as did three primitive neuroectodermal tumors, three rhabdomyosarcomas, two "Askin" tumors, one nephroblastoma, one Ewing's sarcoma, and one malignant melanoma. None of the small cell lymphomas were Leu-7 positive. These results suggest that Leu-7 is a specific neuroendocrine marker in cases of small cell carcinoma, but its sensitivity is lower than that of other "endocrine" determinants. Reactivity patterns for Leu-7 in other small cell tumors demonstrate no specificity for any given line of cellular differentiation. However, the shared expression of this antigen by neuroblastomas, neuroectodermal tumors, Ewing's sarcomas, and Wilm's tumors contributes further to the hypothesis that these neoplasms may be related histogenetically.
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Herpes simplex virus (HSV, probably type 2) antigen was detected in nonpregnant and pregnant endometria, placentae, umbilical cords, and neonatal tissues (companion paper) by avidin-biotin complex immunohistochemical studies. HSV cytologic abnormalities were not detected in any of the 380 cases examined: included were specimens from therapeutic and spontaneous abortions (200 cases) and endometrial curettage (180 cases). The presence of inflammation was not correlated with HSV positivity. Endometrial HSV positivity was significantly correlated with normal late secretory phase (40 per cent of specimens positive), abnormal secretory phase (67 per cent positive), and therapeutic (33 per cent positive) versus spontaneous (26 per cent positive) abortions. Placental HSV positivity was significantly correlated with spontaneous (39 per cent positive) versus therapeutic (14 per cent positive) abortions and with blighted ova (67 per cent positive). No significant correlation was found between HSV positivity and a clinical history of oral or genital HSV infection in either the patient or the male partner. The data support the concept of a subclinical latent intrauterine endometrial HSV infection that is hormonally regulated and can produce transplacental infection of the embryo or fetus, with variable consequences.
Herpes simplex virus (HSV, probably type 2) antigen has been detected in endometria and abortion tissue (companion paper) and in placentae, umbilical cords, and fetal and neonatal organs by avidin-biotin complex immunohistochemical studies. HSV cytologic abnormalities were not detected in any of the 12 normal and 64 abnormal cases analyzed, nor was HSV detected by culture or electron microscopy in selected cases. Antigen was present in single epithelial and, rarely, mesenchymal cells of various organs. Clinically unexplained fetal or neonatal problems associated with HSV antigen positivity included intrauterine death, fetal growth retardation, cystic brain degeneration, hydrops, interstitial pneumonitis, necrotizing enterocolitis, hepatitis, encephalitis, myocarditis, and renal failure. Maternal floor infarct of placenta and calcifying funisitis are the manifestations of intrauterine HSV infection in most cases. Maternal history of HSV infection was uncommon. It is concluded that intrauterine HSV infection may persist in the fetus and neonate in a latent fashion without cytologic abnormalities or detectable virus. This latent infection may be associated with intrauterine and neonatal death, organ damage, and neonatal disease.
Various radiographic patterns were observed for external callus formation of closed femoral shaft fractures treated by closed and open medullary Rush pin fixation. Closed pinning tends to form more adequate lateral callus, to have less looping of bridging callus over the cortex, and to form smooth, dense callus. Open pinning tends to form less lateral callus, to have more looping (radiolucent space under callus) of the callus over the cortex and fracture site, and to have areas of exuberant callus with the appearance of myositis ossificans. The circulatory status of the cortex and soft tissues seem to be a factor in these callus patterns. Avascular cortex of shaft fractures is inferred by the radiographic findings of bridging callus loops over the cortex, relative increased density of cortical bone, and resorption of cortical bone.
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Two cases of lethal carcinoid neoplasia that involved unusual polypoid intraperitoneal metastases rather than the usual flat, sclerotic foci are reported. This type of intraperitoneal polypoid carcinomatosis should alert both the surgeon and pathologist to the possibility of carcinoid neoplasia.
In our experience with 121 patients 18 (15 percent) thyroid nodules studied by needle biopsy were considered indeterminate relative to the presence of a low-grade, well-differentiated carcinoma. For 11 of the 18 patients, operation was performed with carcinoma identified in two (18 percent). Although experience reduced this problem, the frequency of carcinoma justifies operation for patients with indeterminate thyroid nodules by needle biopsy, unless other factors dictate otherwise. Inadequate results of fine-needle aspiration biopsy requires a determination of therapy on the basis of other clinical factors. However, permanent disappearance or great reduction in size following aspiration of cystic nodules, repeat biopsy, and biopsy with large needles are important in supporting nonoperative therapy. The indeterminate and inadequate cases must be considered in assessing reports of the use of needle biopsy of thyroid nodules. The large size of a thyroid nodule and previous external radiation therapy are factors supporting operative treatment. Improved selection of patients with benign thyroid nodules for thyroid hormone suppression therapy is needed--thyroid-releasing hormone testing may be of help.
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Lymph node (LNL) and salivary gland lymphocytes (SGL) from three patients with pseudolymphoma and primary Sjögren's syndrome (1(0)SS) were characterized with monoclonal antibodies to demonstrate (a) a predominance of T cells (greater than 80%) reactive with anti-T cell antibodies OKT4 (greater than 70%) and OKT8 (less than 20%); (b) a high prevalence of activation antigens (greater than 50% of cells reactive with antibody OKT10 and anti-Ia antibody); (c) polyclonal B cells (8-15% of all cells expressing kappa or lambda); and (d) a specific B cell subset defined by reactivity with antibody B532 that was not present in their peripheral blood. In vitro functional studies showed that both SGL and LNL provided T helper activity for immunoglobulin synthesis and that this activity could be abolished by treatment with antibody OKT4 plus complement. The SGL and LNL exhibited little natural killer, antibody-dependent cellular cytotoxicity, or cytotoxic T cell activity. Normal karyotype was observed in SGL, LNL, and peripheral blood lymphocytes (PBL) from these patients. These findings indicate that pseudolymphoma in 1(0)SS results from the infiltration of salivary glands and extraglandular tissues by nonneoplastic T helper cells. Monoclonal antibodies provide an important tool to distinguish pseudolymphoma from non-Hodgkins (B cell) lymphomas that have a markedly elevated incidence in 1(0)SS patients. Our finding of T helper cells in pseudolymphoma tissues supports the hypothesis that chronic stimulation of B cells by helper T cells leads to eventual escape of a malignant B cell clone.
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The authors report a case of spindle cell lipoma that occurred in the perianal region with involvement of the external anal sphincter. This is a very rare location for this benign lipoma. This case extends the range of sites in which this neoplasm is found to arise.
We have reviewed the three-phase bone scans, radiographs, and histologic findings of 39 diabetic patients with serious foot problems. The sensitivity and specificity of bone scans were 83% and 75%, respectively, for osteomyelitis of the small bones of the foot. The positive and negative predictive values were 87% and 69%, respectively. The radiographs were less sensitive (62%) and less specific (69%), with predictive values of 80% (positive) and 47% (negative).
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