Search PubMed⌕ Search

Biomedical subjects

R A Robinson

Publications and source records attributed to R A Robinson.

At least 145 records · Page 8Linked to original sources
PubMed1987

Experimental vascularized bone allografting.

Presented here is a compendium of studies investigating the fate of vascularized bone allografts. The first set of experiments employ the posterior rib graft in two canine models. The rib-to-mandible model was used to evaluate the rejection phenomena of vascularized bone allografts in an outbred dog model. This ascertained the time course of rejection and histological characteristics of the grafts. Immunosuppression of the graft recipients was attempted with azathioprine and cyclosporine. The results demonstrated that azathioprine was not an effective immunosuppressant, whereas cyclosporine resulted in survival of cortical osteons. The use of the vascularized rib allograft, with and without azathioprine, to bridge the defect in the dog femur was met with failure. Further studies employed a genetically defined rat model to determine the effect of different histocompatibilities on the survival of vascularized knee allografts. Grafts were transplanted from Lewis rats to syngeneic Lewis rats as isografts and to Fischer-344 rats (F-344) and Brown-Norway rats (BN) as allografts. Grafts across a major histocompatibility barrier to BN were rejected by 7 days, whereas grafts across a weak histocompatibility barrier to F-344 were rejected more slowly. The use of cyclosporine in this model abrogated the rejection response when administered to both groups continuously. However, a short course of cyclosporine was effective in preventing rejection in the F-344 animals. Efforts to induce tolerance by blood transfusions, from the donor strain or from a third-party donor, were not effective in preventing rejection.

Animals↗
PubMed1987

Warfarin-related purple toes syndrome and cholesterol microembolization.

The "purple toes syndrome" is a rare complication of oral anticoagulant therapy. Four patients who presented with "purple toes syndrome" several weeks after warfarin therapy was initiated are described. The diagnosis of cholesterol microembolization was made by biopsy in three cases. Malignant hypertension and renal failure developed in two patients who died within three to six months of onset of purple toes. Postmortem examination in one of these patients showed widespread cholesterol microembolization. Renal failure has not developed in the other two patients, who are doing well. These biopsy and autopsy results suggest that the warfarin-related "purple toes syndrome" is due to cholesterol microembolization.

Aged↗
PubMed1987

Yield of cancer tissue from prostatic needle biopsy.

This study concerns the quality of human prostatic cancer needle biopsy specimens for routine diagnosis and for bioassay. We examined routine hematoxylin and eosin-stained microscopic sections from 20 prostatic cancer patients, 159 needle cores in all, 71 positive for tumor. Linear core measurements were made with a calibrated ocular micrometer, each segment counted positive if it contained any tumor. Among all subjects there were 35.5 cm of tumor-bearing core length, 26 per cent of the total core length but 60 per cent of the length if completely negative cores were excluded. From these data we calculate a 91 per cent probability of detecting any cancer present if at least 4 cores are taken.

Adenocarcinoma↗
PubMed1987

Experimental autoimmune inflammatory myopathy.

We report an experimental model of autoimmune inflammatory myopathy. Splenic cells from two inbred murine strains (BALB/c and SJL/J) are activated (immunized) in vitro by co-culture with their respective syngeneic skeletal muscle myotubes. Subsequent injection of the activated splenocytes with or without B. pertussis into the respective syngeneic hosts results in inflammatory myopathy in the SJL/J mice but never in the BALB/c mice. The muscle inflammation is very similar in appearance to human autoimmune inflammatory myopathies. The myositis is not effector cell-skeletal muscle specific because splenocytes activated by co-culture with smooth muscle will also elicit skeletal muscle lesions. Both strains of skeletal muscle appear to express class II (Ia) antigens and the splenocytes from both strains appear to be equally activated. Thus we postulate that the difference in the expression of myositis between the two strains is in the effector phase of the disease. Since SJL/J mice have vasoactive amine sensitive vascular systems and BALB/c do not, it is likely that activated splenocytes emigrate from muscle microvessels in the SJL/J strain whereas they cannot do so in the BALB/c strain. The most significant contribution of this model may be in its potential for addressing a sine qua non of cellular autoimmune disease, i.e. lymphocyte migration from the vascular compartment into the target tissue. Finally, the data support a cellular more than a humoral pathogenesis in this model.

Animals↗
PubMed1987

The anterior retropharyngeal approach to the upper part of the cervical spine.

Since 1959, we have used a superior extension of the anterior approach to the cervical spine of Robinson and Smith in a consecutive series of seventeen patients. This approach provided anterior access to the neural elements from the clivus to the body of the third cervical vertebra, without the need for posterior dissection of the carotid sheath or entrance into the hypopharynx or oral cavity. It also provided adequate exposure for the insertion of iliac or fibular strut grafts, which was necessary in thirteen patients. The approach gave excellent exposure for anterior intralesional excision of a tumor in ten patients, marginal excision of an osteochondroma, two corpectomies of the second cervical vertebra combined with removal of the odontoid process, corpectomy of the second cervical vertebra for the treatment of fixed atlanto-axial subluxation, removal of a bullet anterior to the clivus, reduction of a dislocation of the second on the third cervical vertebra secondary to an unstable fracture of the pedicles of the second cervical vertebra, and anterior débridement for treatment of pyogenic vertebral osteomyelitis. In contrast to the reported results of transmucosal approaches to the atlas and axis, there were no infections or iatrogenic neurological deficits of the spine in the present series. Twelve patients who were followed for two years or more had a solid anterior fusion and no subsequent loss of cervical stability. Pain in the neck was relieved in all of the patients who had had a pathological or traumatic fracture.

Adolescent↗
PubMed1987

Review of diseases presenting as "midline granuloma". Clinical implications for the appropriate workup of patients with midline granuloma syndrome with emphasis on recent diagnostic advances in lymphoid neoplasms that present as midline destructive lesions.

Midline destructive disorders (so-called 'midline granuloma') comprise a wide variety of diseases that present as destructive lesions in the upper airways. These diverse diseases include infectious, immune and neoplastic disorders, each of which obviously requires a differing therapy. The clinician must have an appreciation of these diseases in order to make a rational approach to diagnosis. Because of recent advances in immunohistochemical techniques, cell typing will necessitate certain changes in the manner in which biopsy material is initially handled. This paper discusses the differential diagnosis of midline destructive disease, the pathologic techniques necessary to diagnose them and recent ideas concerning the pathogenesis of the malignant lymphoid processes which cause some of these diseases.

Biopsy↗
PubMed1987

Pyogenic osteomyelitis of the occiput, the atlas, and the axis. A report of five cases.

Pyogenic osteomyelitis rarely affects the first and second cervical vertebrae, and when it does it can progress to abscess formation, compressing the spinal cord. If the process is unrecognized, it can be fatal. The cases of five patients are reported. Two patients were treated by anterior débridement and posterior cervical-occipital arthrodesis; one, by transoral drainage; one, by posterior cervical-occipital arthrodesis; and the fifth, by posterior atlanto-axial arthrodesis. The causative organism was Staphylococcus aureus in four patients and Pasteurella multocida in one. In all patients, intravenous antibiotics were used, followed by prolonged administration of oral antibiotics. All five patients recovered.

Aged↗
PubMed1986

Growth control in cerebral microvessel-derived endothelial cells.

Endothelial (En) cells derived from the cerebral microvasculature were examined for their growth control properties. These cells were shown to be growth responsive to fetal bovine serum and arrested growth if serum was removed. They lend themselves to studies in chemically defined media since they survive well in serum-free medium with little or no proliferation. These cerebral microvessel En cells also respond to epidermal growth factor (EGF) and platelet-derived growth factor (PDGF), unlike some other endothelial cells. Similar to other endothelial cells, the En cells responded to fibroblast growth factor (FGF). The response to EGF and PDGF occurred in serum-free media, but only if both agents were present. The cells further responded mitogenically to conditioned media obtained from transformed endothelial cells. The En cells were found to bind EGF and displayed two orders of affinity as determined by Scatchard analysis, depending upon whether the cells were in confluent or subconfluent conditions. The data indicate that some endothelial cells respond to EGF and PDGF and that one mechanism for growth control of endothelial cells may be an ability to regulate high-affinity growth factor receptors for epidermal growth factor.

Animals↗
PubMed1986

Stability of sublines in the R3327-H rat prostatic tumor.

Over several years of in vivo maintenance passage the R3327-H rat prostatic tumor has given rise to nine unique sublines in our laboratory. Some have emerged under selective treatment pressure while others apparently represent spontaneous or random modulation. Each new subline embodied an altered histology, growth rate, metastatic pattern or treatment sensitivity in comparison to its parent subline. However, each has been subsequently passaged enough times to provide evidence of considerable phenotypic stability, a notable point in view of the R3327 tumor's well known potential for modulation.

Animals↗
PubMed1986

Epidemiologic study of Holstein dairy cow performance and reproduction near a high-voltage direct-current powerline.

The development and operation of a high-voltage direct-current (HVDC) transmission line in rural Minnesota generated public concern over potential adverse effects to nearby residents and their livestock. Electrical environmental parameters near an HVDC line decline rapidly with distance, but effects on ambient space charge have been detected out to 1 mile. Previous studies of powerline effects on livestock have involved the more common alternating-current (HVAC) lines, which create a different electrical environment. To identify potential adverse effects of HVDC line operation on livestock, case-control and cohort study methods were used to examine various indices of Holstein performance in relation to distance from the line and the onset of line operation. It was believed that these indices would reflect changes in physiologic function or overt health effects that might arise from the HVDC environment. High-quality performance data from existing Dairy Herd Improvement Association (DHIA) records were obtained for 97% of qualifying herds located within 10 miles of the line. The large number of animals and years of observation provided high statistical power to detect even small systematic changes in performance. No significant differences in milk production or reproductive capacity were associated with presumed exposure to the HVDC environment. The absence of measurable effects in a large "sentinel" animal population may have implications for the assessment of human health risks related to HVDC transmission lines.

Abortion, Veterinary↗
PubMed1986

Interlaboratory comparison of ultrasonic attenuation and speed measurements.

A set of test samples, all containing ultrasonically equivalent tissue-mimicking material, was produced and measurements of ultrasonic speed and ultrasonic attenuation coefficients were made at seven laboratories using various techniques. The ultrasonic speed values agree well with one another, having a spread of about 0.3 per cent; thus, speed values for tissue parenchyma appearing in the literature are likely to be accurate. Values of ultrasonic attenuation coefficients agree fairly well with one another, with differences between individual values and the group mean of generally less than 20 per cent of the group mean.

Humans↗
PubMed1986

Establishment and preliminary growth characteristics of a transformed mouse cerebral microvessel endothelial cell line.

A clone of spontaneously transformed mouse cerebral microvessel endothelial cells has been characterized and its growth characteristics have been investigated. The clone has been designated TEn and has been derived from parent nontransformed cerebral microvessel endothelial cells after multiple passages in culture. These transformed endothelial cells maintained characteristics of other transformed cells: anchorage-independent growth in soft agar, nude mouse tumorigenicity, and growth to high saturation density in culture with lack of contact inhibition. Although transformed, these cells still maintained endothelial functions and markers. These cells respond to both epidermal growth factor and platelet-derived growth factor. Although the TEn cells utilize serum factors for growth, they have maintained in completely serum-free media for up to 3 months. Additionally, serum-free media conditioned by these cells contained a growth factor-like activity that was mitogenic for the nontransformed parent endothelial cells. The TEn cells' maintenance of endothelial functions, growth in serum-free media, production of growth factor-like activity, and the response to well-characterized purified mitogens (epidermal growth factor and platelet-derived growth factor) suggest that these cells may be useful in studying growth control of cerebral microvessel-derived endothelial cells as well as in studies of growth factor production by transformed cells.

Animals↗
PubMed1986

Hepatic teratoma in an anencephalic fetus.

We report a case of hepatic teratoma that occurred in a 21-week-old fetus with anencephaly. This mature teratoma showed tissue derived from all three germ cell layers. To our knowledge, hepatic teratoma associated with anencephaly has not been reported previously.

Anencephaly↗
PubMed1986

Primary neoplasms of the cervical spine. Diagnosis and treatment of twenty-three patients.

The records of twenty-three patients with a primary benign or malignant osseous neoplasm of the cervical spine were reviewed in an attempt to clarify the most appropriate diagnostic and treatment methods for such tumors. Thirteen patients had a benign tumor and ten patients had a malignant tumor. Nineteen patients had been followed for two to eighteen years (average, six years), and four had died from the malignant disease between one and five months after its discovery. In addition to surgery, medical treatment in the ten patients with a malignant tumor included radiation therapy in seven and chemotherapy in two. Surgical treatment consisted of an anterior and posterior partial resection combined with an arthrodesis in four patients; an anterior partial resection in three, two with an arthrodesis; a posterior partial resection and an arthrodesis in two; and a biopsy but no further treatment in one patient. The duration of survival ranged from one to five months for four patients and from two to three years for four, and was eight and sixteen years in two patients. Two of the thirteen patients with a benign tumor received radiation therapy. Surgical treatment included both an anterior and a posterior resection with arthrodesis in four, an anterior resection in three (with arthrodesis in two), a posterior resection in four (with arthrodesis in three), and a biopsy without surgical resection in two. At follow-up, twelve patients were pain-free and had a solid arthrodesis, although one had required a repeat excision posteriorly. One patient with Gorham's disease (diffuse hemangiomatosis) died. During the period of thirty years (1953 to 1983) when these patients were seen, both the diagnostic methods available and the surgical approaches used have changed. Our present opinion is that all primary osseous lesions of the cervical spine should be carefully defined by arteriography, tomography, bone-scanning, computed tomographic scanning, and myelography in order to properly plan the surgical approach. Total excision of suspect malignant lesions is not attempted, but a major intralesional excision should be carried out to decompress neural and vascular structures and to obtain a biopsy specimen, followed by an arthrodesis to stabilize the spine. For both malignant and benign tumors, an anterior resection should be performed if the tumor is located anteriorly, and a posterior approach should be used if the tumor is predominantly in the posterior vertebral elements. Both of these procedures should be combined with an arthrodesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1985

Hemophilus aphrophilus meningitis followed by vertebral osteomyelitis and suppurative psoas abscess.

Hemophilus aphrophilus is an uncommon pathogen in man. It has rarely been reported as a cause of meningitis, exclusively in boys three years or younger. Osteomyelitis due to this organism is also rare. H. aphrophilus was responsible for meningitis, probable thoracic empyema, and ultimately vertebral osteomyelitis and suppurative psoas abscess formation in a woman following metrizamide myelography. The patient responded well to antibiotic treatment and surgical drainage. The organism was sensitive not only to chloramphenicol but also to newer cephalosporin antibiotics.

Abscess↗
PubMed1985

A point-source outbreak of campylobacteriosis associated with consumption of raw milk.

After a one-day field trip to a Minnesota farm, 22 (45%) of 49 third-grade students and three (14%) of 21 adult chaperones developed campylobacteriosis. Campylobacter jejuni was isolated from specimens of 13 children and one asymptomatic adult. Illness was associated with the consumption of raw milk during a picnic lunch (odds ratio = 41.0, P less than .0001) and participation in hand milking of cows (odds ratio = 37.5, less than .0001). Two additional findings implicated consumption of raw milk as the vehicle for transmission. First, the odds ratio for illness among those who drank raw milk and did not milk cows was 11.8 (P less than .01), whereas the odds ratio for illness among those who milked cows but did not drink raw milk was only 1.2 (P greater than .02). Second, there was a dose-response relation between the occurrence of illness and the quantity of raw milk consumed (P less than .0001). Neither the median incubation period nor duration of illness was related to the amount of milk consumed. All persons with a stool culture positive for C. jejuni excreted the organism for at least two weeks, but less than six weeks. No secondary cases of illness were documented.

Adult↗