Biomedical subjects
R J Lanzafame
Publications and source records attributed to R J Lanzafame.
The publishing process.
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Effects of photostimulation on wound healing in diabetic mice.
BACKGROUND AND OBJECTIVE: Low-level laser irradiation at certain fluences and wavelengths can enhance the release of growth factors from fibroblasts and stimulate cell proliferation in vitro. We evaluated whether low-level laser irradiation can improve wound healing in diabetes mellitus. STUDY DESIGN/MATERIALS AND METHODS: Genetically diabetic mice (C57BL/Ksj/db/db) were used as the animal model for this wound healing study. The experimental animals were divided among four groups: negative control, positive control (topical basic fibroblast growth factor [bFGF] on wound), laser therapy group; and a combination group of laser therapy and topical bFGF. An argon dye laser (Lexel Auora Model 600) at a wavelength of 630 nm and an output of 20 m W/cm2 was used as the light source. The speed of wound closure and histological evaluation were used to analyze the experimental results. RESULTS: Laser irradiation enhanced the percentage of wound closure over time as compared to the negative control group (58.4 +/- 2.6 vs. 40.8 +/- 3.4 at day 10 and 95.7 +/- 2 vs. 82.3 +/- 3.6 at day 20, P < .01). Histological evaluation showed that laser irradiation improved wound epithelialization, cellular content, granulation tissue formation, and collagen deposition in laser-treated wounds as compared to the negative control group (6.4 +/- 0.16 vs. 3.8 +/- 0.13 at day 10 and 12 +/- 0.21 vs. 8.2 +/- 0.31, P < .01). CONCLUSION: This study of laser biostimulation on wound healing in diabetic mice suggests that such therapy may be of great benefit in the treatment of chronic wounds that occur as a complication of diabetes mellitus.
Photo-irradiation improved functional preservation of the isolated rat heart.
BACKGROUND AND OBJECTIVE: Photo-irradiation causes a variety of effects in different cells and tissues. We hypothesized that photo-irradiation may improve cardiac preservation based on these observations. STUDY DESIGN/MATERIALS AND METHODS: For pre-storage treatment (Pre), the heart in an anesthetized open-chest rat was irradiated using an Argon-dye laser with a wavelength of 660 nm at a fluence of 16.8 J/cm2 or sham-operated. The heart was excised, perfused with Krebs-Henseleit Buffer, cardioplegically arrested, and stored by immersion at 0 degree C for 18 hrs. Functional recovery was evaluated by working reperfusion for 30 min. For post-storage treatment (Post), the isolated hearts were stored for 18 hrs at 0 degree C; laser irradiation at a fluence of 36 J/cm2 was administered during working reperfusion. Hearts which did not receive irradiation during reperfusion served as control. Furthermore, isolated cardiomyocytes were used to study laser effect on cellular ATP content, catalase activity, and nitric oxide (NO) release. RESULTS: Both Pre and Post groups showed significant improvement in recovery of aortic flow, cardiac output, and work compared to the corresponding control groups (P < 0.05). Combined Pre/Post laser treatment did not improve function. Investigation using isolated rat cardiomyocytes found that both end-storage ATP and end-reperfusion catalase activity in the laser-treated group were significantly higher than those in the untreated cells (P < 0.05). NO release increased by 15% in the laser group after 18 hrs of 37 degrees C incubation. CONCLUSION: Photo-irradiation improves functional recovery of the cold-stored rat heart possibly via conservation of ATP and antioxidant enzyme activity.
Improvement of host response to sepsis by photobiomodulation.
BACKGROUND AND OBJECTIVE: Late sepsis causes immunosuppression and is associated with energy depletion in lymphocytes. Adjuvant treatment with ATP-MgCL2 appears to improve cellular energetics and decrease mortality. Laser irradiation can promote cell proliferation and increase cellular ATP synthesis, which may improve the host immune response in sepsis. The purpose of this study was to determine whether laser irradiation (LI) has a stimulatory effect on the immune response in sepsis using an animal model. STUDY DESIGN/MATERIALS AND METHODS: The cecal ligation and puncture (CLP) rat model was used. Thirty-six SD rats were divided equally among four groups: control (nonoperative), sham operation, CLP treated with laser irradiation, and CLP without laser irradiation. The peritoneal cavity of each animal in CLP/laser group was irradiated immediately after CLP using an Argon-dye laser at a wavelength of 630 nm and at a fluence of 5 J/cm2. Some animals were euthanized 24 hr following CLP and were used to evaluate the immune response (lymphocyte proliferation). In a separate experiment, the survival of septic rats was observed for 60 days. Lymphocytes isolated from normal rat spleens were used to observe for biostimulatory effects in vitro. RESULTS: LI significantly improved ex-vivo lymphocyte proliferation of cells from septic rats (179.7 +/- 17.2 vs. 129.5 +/- 7.8; P < 0.01) and enhanced survival in septic rats (79% vs. 42%; P < 0.001). LI significantly stimulated lymphocyte proliferation in the presence of mitogenic stimuli and enhanced lymphocyte ATP synthesis (P < 0.05). CONCLUSION: LI improves the host immune response and survival rate in sepsis in an animal model. Our studies suggest that LI may be useful as an adjuvant therapy for sepsis.
Preliminary assessment of the tissue effects of a 1.44-micron laser via direct fiber contact on soft tissue.
BACKGROUND/OBJECTIVE: A new pulsed near-infrared laser was developed for incision of soft tissues. This article presents a preliminary investigation of the 1.44-micron laser. METHODS: A prototype laser was used with a cleaved 600-micron quartz fiber (1.44 microns, 5-30 Hz, 30 W max.). Standardized 5-cm incisions were made on skin, striated muscle, and liver in anesthetized New Zealand White rabbits. The animals were euthanized and the tissues were immediately harvested, and histologic examination completed after hematoxylin and eosin (HE) staining. The acute zone of coagulation was measured. A wound healing study was conducted on anesthetized NZW rabbits. The hind leg muscle was exposed and four, 5-cm incisions were made using the laser (0.5 J, 25 Hz) and four incisions were made with an electrosurgical unit on coagulating current (25 W). The incisions were marked and the overlying skin reapproximated. One rabbit was euthanized on day 11 and one on day 21. The wounds were exposed and excised for histology. RESULTS: The acute zone of injury was 1160 +/- 120 microns to 1250 +/- 110 microns for skin; 70 +/- 20 microns to 400 +/- 280 microns for muscle, and 660 +/- 120 microns to 1930 +/- 300 microns for liver. The chronic study demonstrated less inflammation in the laser wounds on day 11 and a chronic inflammatory response on day 21. No gross differences in healing were noted. DISCUSSION/CONCLUSION: The 1.44 microns laser wavelength interacts with tissues in a manner that is substantially equivalent to the holmium laser (2.1 microns). Further studies of the 1.44 microns laser and delivery system development are warranted.
Of frogs, princes, and realities.
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Photomodulation of oxidative metabolism and electron chain enzymes in rat liver mitochondria.
Low-level laser irradiation has been applied in a variety of laboratory studies and clinical trials for photobiostimulation over the last three decades. Considerable skepticism exists regarding the concept of photostimulation within the medical community. One of the major difficulties with photoirradiation research is that it lacks experimentally supportable mechanisms for the alleged photobiostimulatory effects. This study was undertaken to determine whether oxidative metabolism and electron chain enzymes in rat liver mitochondria can be modulated by photoirradiation. Oxygen consumption, phosphate potential, and energy charge of rat liver mitochondria were determined following photoirradiation. Activities of mitochondrial enzymes were analyzed to assess the specific enzymes that are directly involved with the photostimulatory process. An argon-dye laser at a wave-length of 660 nm and at a power density of 10 mW/cm2 was used as a photon source. Photoirradiation significantly increased oxygen consumption (0.6 J/cm2 and 1.2 J/cm2, P < 0.05), phosphate potential, and the energy charge (1.8 J/cm2 and 2.4 J/cm2, P < 0.05) of rat liver mitochondria and enhanced the activities of NADH: ubiquinone oxidoreductase, ubiquinol: ferricytochrome C oxidoreductase and ferrocytochrome C: oxygen oxidoreductase (0.6 J/cm2, 1.2 J/cm2, 2.4 J/cm2 and 4.8 J/cm2, P < 0.05). The activities of succinate ubiquinone oxidoreductase, ATPase, and lactate dehydrogenase were not affected by photoirradiation.
Induction of type II collagen arthritis in the DA rat using silicone gel as adjuvant.
The Dark Agouti (DA) rat has been shown recently to have a high susceptibility for developing arthritis when challenged with either heterologous or homologous collagen II mixed with mineral oil, or with mineral oil challenge alone. This study determined the arthritogenic potential of silicone gel by either mixing it with bovine collagen II (BII) or by injecting silicone gel alone in DA rats. The incidence of collagen induced arthritis was as follows: PBS group- 0/10, silicone gel group- 4/10, and IFA group- 8/9. Anti-BII antibodies were formed in most of the rats treated with either silicone gel or IFA and these groups of rats showed a positive DTH reaction. The PBS treated rats were negative for both anti-BII antibodies and DTH reaction. The incidence of arthritis formation in rats injected with silicone gel alone was 0/10, while the IFA injected rats showed an incidence of 8/10. Silicone gel taken from a commercial breast implant thus is capable of mediating collagen induced arthritis in the DA rat. However, silicone gel alone does not appear to be arthritogenic.
Effects of photodynamic therapy combined with methotrexate on C6 rat glioma cells: a preliminary study.
This study was undertaken to determine if methotrexate (MTX) is effective against tumor cells surviving photodynamic therapy (PDT). C6 rat glioma cells were exposed to Photofrin and irradiated at 630 nm using power densities of 1.2 or 4.8 J/cm2 to simulate the conditions for cells in solid tumors which survive PDT. Cells were then treated with MTX at 5.0, 0.5, or 0.05 microM concentrations. MTT assay of cell proliferation was performed at 24, 48, 72, and 96 h postirradiation. During the first 48 h of incubation, MTX alone was more effective than PDT and MTX. After 48 h, the combination treatment was more effective. Further studies of combined PDT and chemotherapy are warranted.
The effect of lasers, electrocautery, and sharp dissection on cutaneous flaps.
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Induction of type II collagen arthritis in the DA rat using silicone gels and oils as adjuvant.
The relative safety (or otherwise) of silicone gel filled breast implants remains a controversial issue. The Dark Agouti (DA) rat has been shown recently to have a high susceptibility for developing arthritis. This study determined the arthritogenic potential of silicone gel, silicone oil, and the low molecular weight octamethylcyclotetrasiloxane (D4), by either mixing it with bovine collagen II (BII) or by injecting silicone gel alone in DA rats. Three separate experiments were performed using 110 female DA rats with 10 rats per treatment group. The incidence of collagen induced arthritis was as follows: Experiment I (6 micrograms BII)- PBS = 0/10, silicone gel = 4/10, and IFA = 8/9; Experiment II (125 micrograms BII)- PBS = 0/10, silicone gel = 7/10, IFA = 10/10, 1,000 cs silicone oil = 3/10, D4 = 0/10, and 1% D4 in 1,000 cs silicone oil = 1/10; Experiment III (adjuvant alone)-IFA = 8/10, silicone gel = 0/10. Anti-BII antibodies were formed in most of the rats treated with either silicone gel or IFA mixed with BII and these groups of rats showed a positive DTH reaction. The PBS treated rats were negative for both anti-BII antibodies and DTH reaction. Silicone gel taken from a commercial breast implant thus is capable of mediating collagen induced arthritis in the DA rat. However, silicone gel alone does not appear to be arthritogenic.
Laparoscopic cholecystectomy during pregnancy.
BACKGROUND: Cholecystectomy represents the second most common nonobstetric operation during pregnancy. Published guidelines for laparoscopic cholecystectomy (LC) have considered it to be contraindicated in the gravid patient. Several cases of successful LCs in the gravid patient have been reported recently. This study reviews LC during pregnancy in my series and compares this experience with the published literature. METHODS: Five LCs were performed during pregnancy out of 380 cases between May 1990 and November 1994. Forty-one cases were retrieved via MEDLINE search. RESULTS: Three patients were in their second trimester (14, 17, and 22 weeks), and two patients were in the third trimester (27.5 and 28 weeks) in my series. The open technique was used in one patient. Intraoperative cholangiography was not performed. No maternal or fetal morbidity occurred. Forty-one cases have been reported in the literature. Four patients were operated on during the first trimester, 35 during the second trimester, and two during the third trimester (range, 3 to 31 weeks) without fetal loss or maternal morbidity. Cholangiography was performed in 15 cases. Tocolytic agents were used in five of 46 patients. CONCLUSIONS: Although additional clinical data are required, laparoscopic cholecystectomy is safe during pregnancy when undertaken by the skilled laparoscopic surgeon.
The effect of silicone-gel on the immune response.
Silicone materials have been used in medical applications for at least 30 years. Despite this long history of use the question whether silicones can mediate an immunological reaction that may be detrimental to the host remains unanswered. Most studies on the biocompatability of silicones conclude that silicones are chemically stable compounds, which however are often capable of eliciting a benign chronic inflammatory response. Recently, our laboratory has conducted a series of animal experiments aimed at determining the immunological adjuvancy potential of silicone-gel taken from commercial breast implants. Our previous studies have indicated that silicone-gel is a potent humoral (antibody) adjuvant. Our present studies have found that silicone-gel is capable of eliciting auto-antibodies to rat thyroglobulin and bovine collagen II. However this immune response did not produce any histological evidence of thyroiditis or arthritis. Theories to explain why silicone-gel behaves as an adjuvant are discussed along with discussion of the hypothesis on the desirability of replacing silicone-gel with a more hydrophilic material in bioimplants.
The effect of molecular weight and gel preparation on humoral adjuvancy of silicone oils and silicone gels.
Silicone gels from commercial breast implants have been shown previously by our laboratory to be potent humoral adjuvants, while the low molecular size 20 centistoke (cs) silicone oil (M.W. 1900) possesses no measurable adjuvant properties. It became necessary to shear the silicone gel during our previous experiments in order to facilitate injection through a syringe and needle, it is conceivable that shearing may reduce the molecular weight of the silicone gel used. This investigation was undertaken to determine whether humoral adjuvancy of silicone oils is dependent on molecular weight and whether the method of shearing the silicone gel affects its adjuvancy. Four Dow Corning 360 Medical silicone oils (100 cs, M.W. approximately 5,000; 350 cs, M.W. approximately 10,000; 1000 cs, M.W. approximately 16,500 and 12,500 cs, M.W. approximately 60,000) and Dow Corning octamethylcyclotetrasiloxane (D4, M.W. 296) were tested for their humoral adjuvancy by immunizing 64 Sprague Dawley rats with 50 micrograms of bovine serum albumin (BSA) mixed with each oil. The rats were periodically bled and the sera were analyzed for anti-BSA antibodies by ELISA. In a separate experiment, three silicone gel preparations with reproducible characteristics were prepared by using a tissue homogenizer and varying the applied shear force. Each of these preparations was tested for its humoral adjuvancy as previously described for silicone oils. Rats immunized with BSA mixed with the highest molecular size silicone oil tested (M.W. approximately 60,000) showed a significant increase in anti-BSA antibodies as compared to the lower molecular size oils. The three silicone gel preparations showed no difference in their adjuvancy effect. Thus, the humoral adjuvancy of silicone oil appears to be dependent on molecular weight. Differential shearing of the silicone gel does not alter its humoral adjuvancy.