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Biomedical subjects

J L Smith

Publications and source records attributed to J L Smith.

At least 325 records · Page 18Linked to original sources
PubMed1989

Appearance of type II diabetes mellitus in type I diabetic recipients of pancreas allografts.

To determine the cause of hyperglycemia appearing after pancreas transplantation in type I diabetic recipients, we performed 65 oral glucose tolerance tests with serum insulin and C-peptide determinations in 32 patients with pancreas grafts functioning two or more months following transplantation. We correlated these results with estimates of graft size obtained by magnetic resonance imaging (MRI) and values of urinary amylase as a measure of pancreatic exocrine function. A total of 33 studies were obtained in 20 patients at times of normal glucose tolerance, and normal ranges for serum insulin and C-peptide levels were established; 32 studies in 17 patients during periods of glucose intolerance revealed values of serum insulin and C-peptide that were within the normal range, though the time to peak values was delayed to 2 hr, characteristic of type II diabetes. Only 3 of 17 patients examined by MRI had significant pancreatic allograft atrophy. These patients also had low urinary amylase excretion, and the only values for serum C-peptide that were below the normal range. The other 14 hyperglycemic patients had normalized pancreas grafts, normal urinary amylase excretion, and normal values for serum insulin and C-peptide. In our experience, then, in 76% of patients with hyperglycemia more than 2 months following pancreas transplantation, the cause was appearance of type II diabetes rather than destruction of the allograft with recurrence of type I diabetes. This observation has important implications for the definition of pancreas allograft failure and for the management of pancreas allograft recipients with hyperglycemia.

Amylases↗
PubMed1989

Comparison of serum and synovial fluid concentrations of beta 2-microglobulin and C reactive protein in relation to clinical disease activity and synovial inflammation in rheumatoid arthritis.

beta 2-Microglobulin and C reactive protein (CPR) were measured in 33 and 57 matched pairs of serum and synovial fluid (SF) respectively, from patients with active rheumatoid arthritis (RA). Serum beta 2-microglobulin concentrations were higher than in normal controls and the SF concentration was higher than the serum concentration on 25 of 33 occasions (76%), suggesting a local production of beta 2-microglobulin within the synovial membrane. There was a correlation between serum and SF concentrations of beta 2-microglobulin (r = 0.50). Patients' serum CRP concentrations in 57 samples were higher than in normal controls and were greater than in the matched SFs on 49 of the 57 paired samples (86%). In 18 samples CRP was absent in the SF, suggesting a local consumption or binding within the synovial membrane. Twenty four patients with RA given either sodium aurothiomalate or D-penicillamine for six months showed highly significant clinical improvements accompanied by reductions in serum and SF immunoglobulin concentrations and knee joint suprapatellar pouch synovial membrane T lymphocyte infiltrates. In this group of patients serum CRP, but not beta 2-microglobulin, fell significantly, but there were no significant changes in SF beta 2-microglobulin or CRP. These data suggest that serum and SF beta 2-microglobulin concentrations are not a useful index for determining the therapeutic response to sodium aurothiomalate and D-penicillamine and that serum rather than SF CRP concentrations are more helpful. The persistent raised serum and SF concentrations of beta 2-microglobulin probably reflect synovial inflammatory infiltrates, which are still considerable despite apparent clinical remission.

Arthritis, Rheumatoid↗
PubMed1989

Immunohistological features of synovitis in ankylosing spondylitis: a comparison with rheumatoid arthritis.

The immunohistological features of the synovial membrane in ankylosing spondylitis, HLA-B27 associated oligoarthritis, and rheumatoid arthritis wer examined with particular reference to T lymphocyte subsets. T helper (CD4+) cells clearly outnumbered T suppressor/cytotoxic (CD8+) cells in rheumatoid arthritis, whereas both cell types were present in equal numbers in ankylosing spondylitis. A reduction of CD4+/CD45R+ suppressor/inducer cells relative to CD4+/UCHL1+ helper/inducer cells was apparent in all diagnostic groups. The observations were suggestive of disease specific inflammatory responses within synovial membrane.

Adult↗
PubMed1989

HLA class II DR, DQ, and DP restriction fragment length polymorphisms in rheumatoid arthritis.

HLA class II restriction fragment length polymorphisms (RFLPs) were studied in 43 individuals with established seropositive rheumatoid arthritis (RA) and in a group of healthy controls. All patients and controls were tissue typed for HLA-A, B, and DR antigens. Rapid, initial screening for RA associated RFLPs was conducted by pooling DNA samples from 11 HLA-DR4 positive patients with RA and comparing the RFLP patterns with those seen in a pool of DNA samples drawn from 11 HLA-DR4 positive healthy controls. Candidate RA associated RFLPs were examined in our full panel of patients with RA and controls. In most cases the RFLPs detected showed no significant association with RA. An exception was a 13.0 kb DraI DQ beta associated RFLP, which, when HLA-DR4 positive patients with RA and controls were considered alone, showed a weak positive association with susceptibility to RA. This RFLP was not associated with known DR, DQ, or Dw specificities. These results show a distinct paucity of class II RA associated RFLPs but may indicate a role for DQ beta genetic variation in the aetiology of RA.

Arthritis, Rheumatoid↗
PubMed1989

Peripheral T cell lymphoma: value of bone marrow trephine immunophenotyping.

Bone marrow infiltrates taken from 11 patients with peripheral T cell lymphoma were immunophenotyped as T cell lymphoma using monoclonal antibodies on frozen bone marrow trephine biopsy specimens. In nine these were taken at diagnosis and in two after failure of treatment to eradicate lymphoma in the marrow. Patterns of infiltration were as follows: diffuse (n = 4), interstitial (n = 1), nodular (n = 1), focal (n = 5). All cases were CD3 positive and 10 were CD2 positive; five lacked expression of either CD5 or CD7, or both markers. In nine the determination of T cell phenotype depended on analysis of the frozen bone marrow trephine biopsy specimen as there was no other biopsy tissue available for study. In the other two cases there was agreement between the immunophenotypes seen in lymph node and bone marrow infiltrates.

Adult↗
PubMed1989

Pancreatic transplants: evaluation with MR imaging.

Eighty-eight magnetic resonance (MR) imaging studies of 31 pancreas transplants in 30 patients were performed. The postoperative graft usually appears enlarged and inhomogeneous, with patchy areas of increased signal intensity on T2-weighted images that may last 3-4 weeks. During acute rejection, T1-weighted images of graft abnormalities show a decrease in signal intensity, similar to that of muscle, and T2-weighted images show an increase in signal intensity, equal to or higher than that of the bladder. The pattern of abnormal signal is most frequently multifocal but can be diffuse, and the graft may be enlarged. During recovery from rejection, the graft parenchyma shows a decrease in signal intensity (less than that of the bladder) on T2-weighted images when compared with that of acute rejection. During chronic rejection the graft is small and shows low signal intensity, slightly higher than or similar to that of muscle, on both T1- and T2-weighted images. MR imaging appears to be useful for detection of early pancreas allograft rejection and complications in conjunction with clinical findings, laboratory data, and other radiologic procedures.

Acute Disease↗
PubMed1989

Mutable and immutable features of paw-shake responses after hindlimb deafferentation in the cat.

1. Hindlimb paw-shake responses were assessed before and after unilateral deafferentation (L3-S1) in chronic-spinal cats (n = 5), spinalized at the T12 level 1 yr earlier. Selected ankle flexor [tibialis anterior (TA)] and extensor [lateral gastrocnemius (LG)] and knee extensor [vastus lateralis (VL)] muscles were surgically implanted with chronic electromyographic (EMG) electrodes to determine mutable features of cycle characteristics and muscle synergies that are modulated by motion-dependent feedback as opposed to immutable features that are centrally programmed and not modulated by limb afference. 2. Paw-shake responses were difficult to elicit in the extensively deafferented hindlimb; this was true particularly during the first recovery weeks after deafferentation. By the end of the first month, however, brief responses of 1 or 2 cycles were commonly elicited in four of five cats, and responses of 3-7 cycles were common by the end of the second month in three of five cats. Initially, responses in the deafferented limb were elicited by stimuli applied to the dorsolateral thigh, an oval patch of skin innervated by intact S2 afferents. Over the 4-mo recovery period, however, the receptive field of the largely denervated skin expanded, and responses were also elicited by stimuli applied to the lateral aspect of the knee and shank, but usually not the paw. 3. In addition to fewer average cycles per response (5 vs. 10 cycles), paw shaking evoked in the deafferented hindlimb was characterized by longer-than-average cycle periods (124 vs. 98 ms), but the average cycle period varied widely among responses, ranging from 99 to 239 ms. Before deafferentation, the temporal organization of consecutive cycles was stereotypic; cycle periods increased linearly throughout a response. After deafferentation, however, there was no systematic relationship between cycle period and cycle number, and approximately 14% of the records with greater than or equal to 3 cycles were characterized by arhythmical sequences of EMG bursts. 4. At the ankle, LG burst duration was not altered by deafferentation, but TA onset and burst duration were affected. Before deafferentation, TA onset was invariant with respect to the beginning of the cycle, and burst duration increased linearly with cycle period. After deafferentation, however, TA onset was delayed, and the delay increased linearly with cycle period. Consequently, the TA burst duration was brief and unrelated to cycle period.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1989

Hepatic lymphoma in cyclosporine-treated transplant recipients: sonographic and CT findings.

The purpose of this study was to determine the CT and sonographic features of hepatic lymphoma developing in organ transplant recipients taking cyclosporine. The four patients included in the study had non-Hodgkin lymphoma. Two of the cases were primary, with no associated lymphadenopathy or extrahepatic lesions. The hepatic lymphomas were characterized by multiple low-density areas on CT scans and hypoechoic areas on sonograms. In three of the four patients, the lesions regressed after the cyclosporine dosage was reduced. We conclude that in cyclosporine-treated organ transplant recipients, hepatic lymphoma should be considered in the differential diagnosis of hepatic lesions with or without lymphadenopathy when multiple low-density lesions are shown by CT and hypoechoic lesions are shown by sonography.

Adult↗
PubMed1989

Application of magnetic resonance imaging in pancreas transplant.

Various imaging methods have been used in the differential diagnosis of pancreas-transplant dysfunction. As early as 1977, angiography and radionuclide studies ([75Se]seleno-DL-methionine) were used to evaluate pancreas allografts. More recently, the use of 99mTc-labeled DTPA, computed tomography, and ultrasonography has been described, and abnormal findings associated with rejection have been reported with these imaging methods. However, no attempt has been made to determine the ability of each method to detect rejection and to differentiate graft dysfunction caused by rejection from dysfunction by other causes. We summarize our experience with the application of magnetic resonance imaging (MRI) in pancreas transplantation and a comparative study of radionuclide 99mTc-DTPA scans, ultrasonography, and MRI in the detection and differentiation of pancreas-graft dysfunction.

Adult↗
PubMed1989

A comparison of serological, cellular and DNA-RFLP methods for HLA matching in the selection of related bone marrow donors.

Serological, cellular and DNA-RFLP (restriction fragment length polymorphism) methods of determining HLA compatibility between 10 leukaemic patients and potential related bone marrow donors were systematically compared. DR beta/DQ alpha/DQ beta/DNA-RFLP typing of these families gave results in agreement with those obtained by serological methods (matching for HLA-A, -B and -DR), supported by mixed lymphocyte culture (MLC) data, indicating the validity and accuracy of DNA-RFLP matching in transplantation. However, a significant minority of four leukaemic patients plus two healthy individuals were not clearly HLA-DR typable by serology, but all such individuals were easily typable by DNA-RFLP. These results were supported by MLC data, where available. In addition, all data were in agreement with previously reported correlations between DNA-RFLPs and HLA-DR serology, allowing unambiguous assignment of HLA-DR types where these were previously in doubt. These results demonstrate the value of DNA-RFLP HLA class II DR and DQ typing in leukaemic patients requiring marrow transplantation who are not clearly typable by traditional methods and suggest that this approach should constitute an important element of future HLA matching programmes for bone marrow transplantation.

Bone Marrow Transplantation↗
PubMed1989

Ocular disease in Caribbean patients with serologic evidence of Lyme borreliosis.

Four patients from Caribbean and Central American countries with ocular disease and serologic evidence of Lyme borreliosis are discussed. To our knowledge this is the first report of Lyme disease from this geographic area. Two patients exhibited ocular inflammatory disease, and two patients developed optic neuropathy. A brief discussion of Lyme borreliosis, its serologic diagnosis, and its treatment is presented.

Adult↗
PubMed1989

Echographic correlation of optic nerve sheath size and cerebrospinal fluid pressure.

A 23-year-old obese woman presented with papilledema. Computed tomography showed no intracranial mass lesions and lumbar puncture revealed an increased opening pressure, confirming the diagnosis of pseudo-tumor cerebri. Standardized echography of the optic nerves was performed immediately before and after lumbar puncture. A marked reduction of cerebrospinal fluid pressure correlated with a decrease in the subarachnoid fluid of the optic nerve sheath.

Adult↗
PubMed1989

The prevalence of Lyme disease in a nonendemic area. A comparative serologic study in a south Florida eye clinic population.

Serologic tests for Lyme borreliosis and for syphilis were performed on 75 patients seen in a 1-week period at the Bascom Palmer Eye Institute in Miami. The incident of syphilis was 8% and of Lyme borreliosis 3% in this study in a nonendemic area. The most common cause for a high titer serologic response for Lyme borreliosis in this group was a prior Treponema pallidum infection. The importance of getting VDRL, FTA-ABS, Lyme IFA, and Lyme ELISA tests in all suspected cases was emphasized.

Adult↗