PubMed Health⌕ Search

Biomedical subjects

M Port

Publications and source records attributed to M Port.

At least 37 records · Page 2Linked to original sources
PubMed1997

Overexpression of glucose transporter 1 and increased FDG uptake in pancreatic carcinoma.

UNLABELLED: Increased glycolysis is a characteristic metabolic feature of a malignant transformed phenotype. In cultured cells transformed by viruses or activated oncogenes, enhanced glycolytic metabolism is mediated by the overexpression of glucose transporter 1 (Glut-1) and key regulatory glycolytic enzymes. Whether increased glucose metabolism in solid human malignant tumors is related to the overexpression of key regulatory proteins of glucose metabolism is presently unknown. We thus studied the expression of Glut-1 and glucose uptake, assessed with 2-fluorodeoxyglucose (FDG) and PET in human pancreatic carcinoma (PC) and chronic mass-forming pancreatitis (MFP). METHODS: Glucose uptake was measured in the fasting state with FDG and PET in 12 patients with PC and 15 patients with MFP. The standardized uptake value (SUV) of FDG was determined as a global quantitative measure of tissue glucose utilization in cancer tissue or MFP. The expression of Glut-1 and Glut-4 was analyzed from operatively removed cancer or MFP tissue by Northern analysis or semiquantitative reverse transcriptase-polymerase chain reaction. The count ratio of Glut-1 to Glut-4 transcripts was used as an indicator of selective Glut-1 up-regulation. RESULTS: The SUVs of FDG in patients with cancer and MFP were 2.98 +/- 1.23 and 1.25 +/- 0.51 (p < 0.01), respectively. Northern analysis showed intense Glut-1 expression in four of five patients with cancer but not in any of the five patients with MFP that were tested. In PC, Glut-1 and Glut-4 transcripts were found in five of five and three of 10 patients, respectively, using reverse transcriptase-polymerase chain reaction, whereas in MFP, Glut-1 was detected in one of five and Glut-4 was detected in all five patients. The Glut-1-to-Glut-4 transcript ratios were 6.17 +/- 1.27 in patients with cancer and 0.42 +/- 0.12 in patients with MFP. The mean Glut-1 concentration in eight patients with cancer was 1.71 nmol of Glut-1 mRNA/microg of mRNA (range, 0.0446-9.43) and 0.15 (range, 0-1.55) (p < 0.05) in 13 patients with MFP. CONCLUSION: The concomitant enhancement of glucose utilization and selective overexpression of Glut-1 mRNA in pancreatic cancer but not in MFP suggested constitutive activation of Glut-1 gene or decreased degradation of Glut-1 mRNA in human pancreatic cancer. These findings may imply a potential for the early detection of pancreatic cancer with FDG and PET and identify new targets for anticancer therapy.

Adult↗
PubMed1997

Six month clinical evaluation of a biomimetic hydrogel contact lens.

PURPOSE: We performed a six-month, comparative, contralateral/bilateral study to assess the clinical performance of the Proclear contact lens, which is manufactured from a novel, biomimetic, 59% water content, hydrogel material (Omafilcon A). Omafilcon A is a hydrogel polymer and is based on a new biomimetic approach to the design of biomaterials for biomedical applications. The polymer incorporates a synthetic analogue of the phosphorylcholine (PC) headgroup, an important component found in all human cells. METHODS: Forty-two subjects were fit with the Proclear lens for 6 months of daily wear; 20 subjects wore a Proclear lens in one eye and a Permaflex lens in the fellow as a control, while 22 subjects wore Proclear lenses in both eyes. A one-step hydrogen peroxide system was used for disinfection and no protein remover was used. RESULTS: No subject was required to withdraw due to unacceptable physiological findings with the Proclear lens. At the 3-month visit, corneal staining was present in 33% of the Proclear eyes compared to 72% of the Permaflex-wearing eyes. At one month, the Proclear lens was graded significantly more comfortable than the Permaflex lens (P < 0.01), and all 11 of the subjects who expressed a preference did so in favor of the Proclear lens. Overall, the fitting characteristics and visual performance of the Proclear lens did not appear to vary during the study. Spectrofluorimetric analysis of worn lenses confirm that Proclear showed minimal protein and lipid spoliation, which was found to be independent of wear time and subject variations. In contrast, despite the use of a surfactant cleaner, Permaflex lenses showed measurable and significant levels of lipid spoilation. Despite significant differences in average mean thicknesses and the level of bulk water in the lenses, in vivo dehydration of the Proclear lens was significantly lower than that of the Permaflex lens. CONCLUSIONS: The results of this study have confirmed the viability of biomimetic PC-hydrogels in contact lens applications. In vivo and in vitro analyses tended to confirm that Omafilcon A has a number of superior material attributes, as compared to conventional hydrogels when used in contact lens applications.

Adolescent↗
PubMed1997

Clinical comparison of Omafilcon A with four control materials.

PURPOSE: The purpose of this study was to assess the clinical performance of hydrogel contact lenses manufactured from a novel, biomimetic, 59% water content, hydrogel material (Omafilcon A) as compared with a representative range of control materials (Polymacon, Etafilcon A, Atlafilcon A, and Welcon CE). METHOD: Thirty subjects were enrolled in a 2-month, double-masked, randomized, comparative, daily wear study. Subjects wore two sets of lenses; each pair was worn for 1 month. In each part of the study, subjects wore a Proclear (Biocompatibles Ltd.) test lens (Omafilcon A) in one eye and a control lens in the other eye. In vivo lens dehydration was measured after 1 week of lens wear. Lenses were collected at the end of the study and subjected to in vitro spectrofluorimetric analysis to measure protein and lipid deposits. RESULTS: Omafilcon A showed significantly less lipid spoilation than all the controls and significantly less protein than the Etafilcon A and Atlafilcon A lenses. High levels of protein were found on the Group 4 lenses (Etafilcon A) and high levels of lipid were found on the Group 2 lenses (Weicon CE). The Omafilcon A lenses exhibited significantly less on-eye dehydration than the Etafilcon A lenses (P < 0.0001) and the Weicon CE lenses (P < 0.005). The majority of subjects expressed a preference for the Proclear lens, generally for reasons of comfort. Some minor differences in aspects of lens fit were noted between the test and control lenses, however, none of these were felt to be great enough to affect comfort. CONCLUSIONS: We hypothesize that the reduced spoliation seen with the Omafilcon A lens relates to the biomimetic nature of the material which incorporates phosphorylcholine.

Adsorption↗
PubMed1995

Topical treatment of onychomycosis.

Onychomycosis continues to be one of the more common foot problems encountered by podiatrists. Although a reliable cure is elusive, this article reviews several new agents that show some promise.

Administration, Cutaneous↗
PubMed1995

Varifocal contact lenses for the correction of presbyopia.

A Nissel +1.75 D PS45 lens' label power seems to be made up of about +0.75 D distance and +0.75 D near addition. There are individual variations which will depend on pupil size, corneal shape, lens position and ocular aberrations. When a +0.75 Bausch & Lomb U3 lens was used as a control, there was also a significant increase in 'accommodation' measured (+0.75 D), but this could not be explained. When two other lenses with an aspheric surface were studied, they also showed a near addition effect. In this supplementary study the changes were explained by changes in spectacle accommodation. A lens with two spherical surfaces did not show the expected increase in spectacle accommodation. Astigmatism, as a general rule, was not corrected by the PS45 lens, although the very occasional case did show some reduction. Visual acuity and contrast sensitivity at 8 cpd and 3 cpd were not significantly affected when compared to the control lens.

Accommodation, Ocular↗
PubMed1993

Attachment to extracellular matrix molecules by cells differing in the expression of osteoblastic traits.

Two sets of clonal cell populations differing in the expression of osteoblastic traits, the rat osteosarcoma cell lines ROS 17/2.8 and ROS 25/1 and the immortalized fetal rat calvarial cell lines RCT-1 and RCT-3, were compared for their ability to attach to a series of extracellular matrix (ECM) constituents in vitro. Both osteoblastic (ROS 17/2.8, RCT-3) and nonosteoblastic (ROS 25/1, RCT-1) cell lines attached in a time- and concentration-dependent manner to plates coated with fibronectin (FN), osteopontin (OP), type I collagen (Col I), type IV collagen (Col IV), and laminin (LN) but only weakly to osteocalcin (OC) and thrombospondin (TSP). In both systems, the osteoblastic and nonosteoblastic clones attached identically to FN. Both ROS 17/2.8 and ROS 25/1 attached to similar molar amounts of substrate with the same preference order: FN > LN > Col I > or = Col IV. Maximal ROS 17/2.8 attachment to OP was > or = Col I but required approximately 2.5 times more substrate. ROS 25/1 attached less effectively than ROS 17/2.8 to most non-FN substrates. RCT-3 cells attached similarly to ROS 17/2.8 except that the preference order for Col I and LN was reversed and attachment to OP was lower than for ROS 17/2.8 RCT-1 cells attached best to Col I rather than FN, and equaled or surpassed RCT-3 in attachment to other non-FN substrates. Thus in these experimental systems, cells expressing an osteoblast-like phenotype exhibited generally similar ECM attachment properties. Their nonosteoblastic counterparts recognized the same spectrum of ECM constituents but differed from the osteoblastic cells and from each other in the effectiveness of their attachment to substrates other than FN.

Animals↗
PubMed1993

Operating room personnel morbidity from carbon dioxide laser use during preceptored surgery.

OBJECTIVE: To determine the extent of laser-induced morbidity away from the operative site during the preceptor phase of laser credentialing in our institution. METHODS: All laser surgeries performed from June 1, 1990 through May 31, 1991 and preceptored by one of the authors (MB) were included in the study. All of the surgeries were performed by a resident or attending physician seeking laser privileges in our institution. During that time, 141 such cases were performed. RESULTS: In 13 of 141 cases (9%), there were injuries unrelated to the surgical procedure itself to either the patient or operating personnel. There were nine accidents associated with laser use during 42 laparotomy procedures (21%) and four accidents at the time of 44 vulvar surgeries (9%). There were no accidents during laparoscopic or colposcopic surgery of the vagina or cervix. CONCLUSIONS: Despite extensive training requirements before use of the CO2 laser, accidents did occur. Operating room safety requirements should be a high priority to minimize morbidity. We report our experience with intraoperative morbidity caused by surgeons' errors and present recommendations to limit further complications.

Accidents↗
PubMed1992

Rigid gas-permeable extended wear: a comparative clinical study.

A 12-month clinical trial involving 88 subjects was undertaken to compare the clinical performance of rigid gas-permeable contact lens extended wear (EWRGP) with that of RGP daily wear (DWRGP) lenses and soft lens extended wear (SLEW) with medium water content lenses. Withdrawals from the EWRGP group tended to result from lens-related problems, whereas the SLEW withdrawals generally resulted from adverse effects on corneal physiology. Changes in spherical refractive error during the 1-year study were small (less than 1.00 D) and similar for both gas-permeable lens-wearing groups. Most of the SLEW group (58%) showed an increase in myopia and the mean increase was 0.38 D, which represented a significant difference from the EWRGP group. The EWRGP group showed a mean flattening in corneal curvature of 0.11 and 0.15 mm in the flattest and steepest corneal meridians, respectively. A positive correlation was noted between change in corneal curvature and baseline corneal astigmatism, which suggests corneal molding as a result of lid pressure as the most likely cause. The DWRGP and SLEW groups showed small, nonsignificant changes in corneal curvature. Most of the EWRGP subjects (69%) who completed the study showed increased corneal distortion. This compares with 30 and 17% with the DWRGP and SLEW groups, respectively. Likely corneal edema was a major contributory factor. For most of the slitlamp variables monitored, there were no significant differences between the groups. However, microcystic changes were detected in both EWRGP (35%) and SLEW subjects but not in the DWRGP group. Corneal staining was noted in all groups but was more prevalent among the EWRGP group. The findings of this study are discussed in relation to the clinical management of RGP extended wear.

Adolescent↗
PubMed1990

Aggressive digital papillary adenoma: a case report.

Aggressive digital papillary adenoma has only been identified as an entity within the past six years. Only forty patients have been reported in the literature with this lesion. The lesion is found three times more commonly on the hands than on the feet. The lesion typically enlarges slowly and is asymptomatic. Patients in half of the reported cases have experienced local recurrence after initial removal. The authors present a case of aggressive digital papillary adenoma of the foot.

Aged↗
PubMed1986

Rounds in podiatric dermatology.

Dr. Port presents six cases, which he refers to as "zebras," with clinical descriptions and discussions that typify his excellent teaching style. He also alludes to the fact that podiatrists need to be thorough in their history and physical evaluations. After a lesion has been treated appropriately and does not respond, additional investigation is in order. These cases are interesting to read but, most importantly, any one of these atypical patients could be seen in our offices tomorrow.

Adenoma↗
PubMed1978

Zosteriform lentiginous naevus with ipsilateral rigid cavus foot.

A patient is presented with a rigid cavus deformity associated with a painful linear keratotic lesion on the lateral plantar border. A unilateral zosteriform lentiginous naevus is found on the same side as the foot deformity. Electrodiagnostic evaluation suggests the presence of a non-specific neuromuscular process on the affected side. This association has not previously been reported.

Adult↗