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Biomedical subjects

N Fine

Publications and source records attributed to N Fine.

At least 19 recordsLinked to original sources

Flap prefabrication in the head and neck: a 10-year experience.

Tissue neovascularized by implanting a vascular pedicle can be transferred as a "prefabricated flap" based on the blood flow through the implanted pedicle. This technique potentially allows any defined tissue volume to be transferred to any specified recipient site, greatly expanding the armamentarium of reconstructive options. During the past 10 years, 17 flaps were prefabricated and 15 flaps were transferred successfully in 12 patients. Tissue expanders were used as an aid in 11 flaps. Seven flaps were prefabricated at a distant site and later transferred using microsurgical techniques. Ten flaps were prefabricated near the recipient site by either transposition of a local vascular pedicle or the microvascular transfer of a distant vascular pedicle. The prefabricated flaps were subsequently transferred as island pedicle flaps. These local vascular pedicles can be re-used to transfer additional neovascularized tissues. Common pedicles used for neovascularization included the descending branch of the lateral femoral circumflex, superficial temporal, radial, and thoracodorsal pedicles. Most flaps developed transient venous congestion that resolved in 36 to 48 hours. Venous congestion could be reduced by incorporating a native superficial vein into the design of the flap or by extending the prefabrication time from 6 weeks to several months. Placing a Gore-Tex sleeve around the proximal pedicle allowed for much easier pedicle dissection at the time of transfer. Prefabricated flaps allow the transfer of moderate-sized units of thin tissue to recipient sites throughout the body. They have been particularly useful in patients recovering from extensive burn injury on whom thin donor sites are limited.

Adolescent↗

Primary cysts in the iridociliary sulcus: ultrasound biomicroscopic features of 210 cases.

BACKGROUND: Primary cysts occur spontaneously, whereas secondary cysts arise following surgical or nonsurgical injury and can lead to further complications. We performed a study to observe and characterize primary iridociliary cysts through the examination of ultrasound biomicroscopic (UBM) images from affected patients. METHODS: The UBM images from 210 patients were analysed and the characteristics of each cyst were observed and recorded. The patients had been examined and received the diagnosis of iridociliary cysts between 1990 and early 1998 at a major referral centre for the diagnosis and treatment of cancer in Toronto. RESULTS: Of the 210 cysts 169 (80%) occurred in isolation, and the remainder occurred in the presence of a tumour. The mean horizontal diameter of the isolated cysts was 1.72 mm, and the mean vertical diameter was 1.04 mm. Isolated cysts were solitary in 101 cases (60%) and showed multiple loculations in 68 (40%). Solitary cysts were slightly larger than those with multiple loculations. Isolated cysts were associated with markedly narrowed or closed angles locally in 110 cases (65%). INTERPRETATION: Primary iridociliary cysts are common and need to be differentiated from iris and ciliary body tumours. UBM is a definitive method of diagnosing these lesions. Cysts can cause localized angle closure but rarely cause clinical complications. Cysts associated with anterior segment tumours may give an erroneous impression as to tumour size.

Anterior Chamber↗

Percutaneous drainage of subcapsular splenic hematoma: an experimental model in dogs.

Preservation of the spleen in patients with posttraumatic subcapsular hematoma is still controversial. To determine the best therapeutic approach for this type of splenic injury, we designed an experimental model of subcapsular hematoma of the spleen in dogs. A total of 23 subcapsular hematomas were caused in 19 dogs, which were followed both clinically and ultrasonographically for 12 weeks. Fifty-seven per cent of the hematomas resolved spontaneously; those that persisted (43%) were aspirated percutaneously with ultrasound guidance, after which they were all resolved. Our results support a conservative approach. When the hematoma does not resolve spontaneously, percutaneous ultrasound-guided aspiration may be considered.

Animals↗

Decreased expression of CD73 (ecto-5'-nucleotidase) in the CD8+ subset is associated with zinc deficiency in human patients.

We used flow cytometry to observe the changes in T cell populations resulting from zinc deficiency in subjects with sickle cell anemia (SCA) and in healthy human volunteers without SCA. Zinc deficiency was associated with significant decreases in cellular zinc concentration, CD4+/CD8+ ratio, and percentage of CD73+ cells in the CD8+ population. The decrease in the percentage of CD73+ cells in the CD8+ subset was significantly correlated with lymphocyte zinc concentration and was accompanied by essentially no change in the percentage of CD11b+ cells in the CD8+ subset. Daily oral zinc supplementation in nine zinc-deficient human volunteers (25 mg elemental zinc) and in seven zinc-deficient SCA subjects (50 mg elemental zinc) resulted in increases in the absolute lymphocyte count and significant increases in the CD4+/CD8+ ratio and in the percentage of CD73+ cells in the CD8+ subset. In zinc-supplemented subjects, the increase in the percentage of CD73+ cells was accompanied by a significant decrease in the percentage of CD11b+ cells in the CD8+ subset. Changes in the CD4+/CD8+ and CD73+/CD11b- cell ratios in the CD8+ subset after treatment may provide a useful diagnostic criterion for zinc deficiency in humans.

5'-Nucleotidase↗

Expression of complement regulatory proteins on fetal blood cells in utero.

Since the fetus is semiallogenic to the mother, mechanisms have evolved to protect fetal tissue from the maternal immune response. Among these mechanisms is the expression of cell-surface complement regulatory proteins at the maternal-fetal interface. However, beginning in the third trimester, fetal blood cells are exposed to actively-transported IgG antibody. Thus, we speculated that fetal blood cells would require expression of one or more complement regulators by the early third trimester. Using flow cytometry and Western blots, we have demonstrated the presence of three important complement regulatory proteins in the circulating blood cells of human fetuses. These findings are consistent with the putative biological role of the cell-surface complement regulatory proteins.

Antigens, CD↗

Diminished expression of cell-surface complement regulatory proteins in HIV-infected children and with HIV infection of peripheral blood mononuclear cells in vitro.

Experimental data have established that HIV-infected lymphocytes activate the complement system. However, because mammalian lymphocytes possess a series of cell-surface complement regulators that inhibit amplification on autologous cells, complement-mediated destruction of host cells is usually inhibited. These studies were performed to examine whether alterations in the cell-surface complement regulatory proteins decay-accelerating factor (DAF, CD55) and membrane cofactor protein (MCP, CD46) may occur during HIV infection in vitro or in vivo. The physiologic significance of these alterations were assessed by radiolabeled chromium release experiments. We show that MCP fluorescent intensity is significantly lessened in HIV-infected children and that DAF intensity is similarly lessened in infected children with advanced disease. These findings could be duplicated with HIV infection of peripheral blood mononuclear cells in vitro.

Adult↗

The effect of bisphosphonate on alveolar bone resorption following mucoperiosteal flap surgery in the mandible of rats.

Following elevation of a full thickness flap a transient burst of regional remodeling occurs. This phenomenon is termed in orthopedic surgery as regional accelerated phenomenon (RAP), beginning with accelerated resorption activity followed by a slow process of bone regeneration. Recently we have demonstrated that a mucoperiosteal surgical flap of rat mandible is producing a typical RAP process. Bisphosphonates are synthetic compounds that are taken up preferentially by the skeleton and suppress osteoclast-mediated bone resorption by a mechanism that is not yet fully understood. Amino bisphosphonate has been shown to inhibit active bone resorption without interfering with bone formation. In this study we evaluated the effect of amino bisphosphonate on bone resorption associated with a mucoperiosteal flap used as a resorptive model. We compared the effect of amino bisphosphonate in rats using IV administration with topical application at 3 dose levels. The results show that topical application of all 3 doses (0.15, 0.75, and 1.5 mg/ml) had no inhibiting effect on bone resorption after surgery, while IV administration at 0.5 mg/kg body weight significantly reduced the bone resorption. Interestingly, in the non-operated side, amino bisphosphonate increased mineral density.

Administration, Topical↗

Regional accelerated phenomenon in the mandible following mucoperiosteal flap surgery.

Striking remodeling activity occurs adjacent to the site of injury in orthopedic surgery. This reaction has been described as regional accelerated phenomenon (RAP), as it speeds up the healing stage. The phenomenon is a transient burst of localized remodeling process following surgical wounding of cortical bone. We explored whether RAP occurs following mucoperiosteal flap surgery in the jaw bone. Mucoperiosteal flaps were performed on 60 Wistar rats, either only on the buccal aspect or both on buccal and lingual aspects of the mandible. The surgical procedure lasted an average of 30 seconds and the flap was readapted without sutures. The rats were sacrificed at 3, 7, 10, 14, 21, and 120 days. High resolution x-ray microradiography of 1 to 1.5 mm thick ground sections between premolar and molar regions of the mandible were analyzed and revealed large areas of radiolucency which correlated to massive resorption of the alveolar bone, as well as areas in the bone proper. The RAP was observed as early as 10 days in the treated side group. Striking resorption of the cortical bone, both on the surface and the bone proper, occurred on the periodontal aspect of the crestal bone leading to widening of the periodontal ligament space, where a mucoperiosteal flap was performed on the buccal aspect. The resorption was more prominent when a mucoperiosteal flap was performed both on the lingual and buccal aspect. The alveolar bone recovered almost to control levels 120 days after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗

Increase in CD5+ B cells in juvenile rheumatoid arthritis. Relationship to IgM rheumatoid factor expression and disease activity.

OBJECTIVE: To investigate the association between CD5+ B cell expression and IgM rheumatoid factor (IgM-RF) in juvenile rheumatoid arthritis (JRA). METHODS: CD5+ B cell levels analyzed by flow cytometry and IgM-RF expression determined by enzyme-linked immunosorbent assay were compared in children with JRA, children with other collagen vascular diseases, and healthy controls. RESULTS: Children with polyarticular JRA had expanded populations of CD5+ B cells, and expansion of CD5+ B cells and IgM-RF both correlated with disease activity. CONCLUSION: The results indicate that an expanded CD5+ B cell population leads to IgM-RF production in patients with polyarticular JRA, as well as patients with RA.

Antigens, CD↗

Circulating lymphocyte subsets in second- and third-trimester fetuses: comparison with newborns and adults.

OBJECTIVES: Our objective was to compare the relative sizes of circulating lymphocyte subsets in fetuses, newborns, and adults. STUDY DESIGN: Two-color flow cytometric analysis of lymphocyte cell surface markers was performed on blood from 64 fetuses, 22 newborns, and 67 normal adults. RESULTS: All three groups had similar percentages of CD3+ total T cells, CD4+ helper T cells, CD8+ cytotoxic/suppressor T cells, and CD20+ B cells. Compared with adults, fetuses and newborns had markedly reduced percentages of CD57+ natural killer T cells and consistently increased percentages of CD5+CD20+ B cells. Most fetal and cord T and B lymphocytes expressed the activation marker CD38. CONCLUSIONS: Similarities and age-dependent differences exist among fetal, newborn, and adult circulating lymphocyte subsets. Lymphocyte marker analysis may prove useful in the detection of fetal infection and other complications of gestation.

Adult↗

Rectal epithelial proliferation in persons post sporadic colorectal neoplasia.

Some studies have shown diffuse large bowel epithelial hyperproliferation in persons having colorectal neoplasia. Thus, measurements of rectal epithelial proliferation (REP) could be useful as a screening biomarker of risk for sporadic neoplasia. We examined REP, by autoradiography with tritiated thymidine, in 84 persons: 32 healthy volunteers, 37 who had had sporadic adenomas and 15 post cured sporadic colorectal cancer. Measurements of the labelling index (ratio of labelled to total number of crypt cells) showed a statistically insignificant but increasing gradient of hyperproliferation related to degree and invasiveness of neoplasia. However, this became significant when examining the proportion of labelled crypt compartments in each group and by comparing combined compartments 3 and 4 of cancer patients to non-cancer patients. Gender and age were found to be parameters that influenced the results. Using standard methods of analysis of REP, the lack of clear separation between risk groups limits the usefulness of REP measurements as a screening biomarker of risk for sporadic large bowel neoplasia.

Adenocarcinoma↗

Rectal epithelial proliferation in women recovered from breast cancer.

Women recovered from breast cancer are at increased risk for colorectal neoplasia. The reasons may be genetic, dietary or endogenous hormonal risk factors. Measurements of rectal epithelial proliferation are a useful biomarker of risk for large bowel cancer. This was studied in 12 women after (mean 7.8 years) cured breast cancer, who had a mean % labelling index of 7.5 +/- 3.5 (S.D.) as compared to 5.8 +/- 1.8 (S.D.) in a disease-free comparison group of 25 women. In addition, analysis of labelled crypt compartments demonstrated a significantly higher proportion in the study group with thymidine uptake, mainly in the mid crypt zone, and an extension of crypt cell DNA synthesis towards the surface epithelium. Using proliferative activity as a biomarker of risk in a larger study group, we may learn more about common etiological factors for both malignancies and also identify a higher-risk subgroup for long-term follow-up and possible therapeutic intervention.

Aged↗

Rectal epithelial proliferation characteristics of first degree relatives of sporadic colon cancer patients.

Hyperproliferation of rectal epithelium is characteristic of families at high genetic risk for large bowel neoplasia, but has not been well-documented in families of sporadic colorectal cancer patients. This was studied in 119 such first degree relatives and 44 comparison subjects without this family history. All screened negative for large bowel neoplasia. Within the family group proliferation was significantly higher in the men and those aged less than 45 years, also higher (insignificantly) in non-Europeans and those having greater than 1 first degree colorectal cancer relative. In comparison to the nonfamily group the labelling index (LI) of the relatives showed a significant negative correlation with age (R = -0.20, P = 0.03). Within this family group the probability of having an elevated LI (greater than 6.0%) was greatest in the young (less than 50 years old) men (odds ratio = 2.0). Measurements of rectal epithelial proliferation (REP) in these first degree relatives, at a young age, might help delineate a high risk subgroup for prospective primary and secondary intervention.

Adult↗

Effect of a calcium-enriched diet on the colonic epithelial hyperproliferation induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats on a low calcium and fat diet.

We examined whether hyperproliferation of colonic crypt epithelium during cancer induction by N-methyl-N-nitro-N-nitrosoguanidine (MNNG), in rats on a low fat and calcium diet could be reduced by added calcium p.o. From the age of 4 weeks, 104 male Sprague-Dawley rats received a low fat (3.5%), low calcium (0.05% calcium ion), and low vitamin D (0.4 IU/g) diet. Sixty-four also had calcium salts, derived from either calcium lactate or solubilized calcium carbonate, added to their drinking water; therefore their total calcium intake was about 1% of daily diet. At age 12 weeks the rats were divided into 4 treatment groups: 8 rats, not receiving added calcium, had rectal saline instillations weekly (saline control group) and were sacrificed after a further 28 weeks; 3 groups of 32 rats each received intrarectal MNNG (1.5 mg) weekly. One group, not receiving added calcium, was the MNNG control group; while the second group also received added calcium lactate, and the third group received calcium carbonate. Groups of 24 were sacrificed periodically until 28 weeks of treatment. Rats were sacrificed and epithelial proliferation was estimated, 1 week after the last intrarectal instillation, by in vivo labeling with tritiated thymidine and measuring the ratio of labeled to total colonic crypt epithelial cells. The mean labeling index of the MNNG treated and added calcium groups were significantly higher (8.7-9.5%) than that of the saline controls (2.8%) only at week 28; however, it was then still significantly less than that of the MNNG controls not having added calcium (17.9%). Hyperproliferation, during induction of colonic cancer by MNNG in rats on a low calcium diet, can be reduced by a calcium enriched diet even in the presence of a low fat intake.

Animals↗

Influence of demographic parameters on rectal epithelial proliferation.

Measurement of rectal epithelial proliferation is now being used as a biomarker for assessing risk for colorectal cancer and response within dietary intervention studies. We examined the possible confounding effects of demographic parameters on the proliferation of 52 healthy middle-aged volunteers without known risk factors for colorectal cancer. No significant effects on proliferation of age, sex or ethnic grouping were found other than marked urban-rural differences amongst men. We hypothesise that these could be explained by differences in dietary habits and their deleterious effects in the older male population. Careful matching of controls are probably needed in order to demonstrate the minor changes in mucosal proliferation that could reflect risk for neoplasia. Further human studies are needed to examine the effects of diet and extremes of age on proliferation.

Adult↗