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PubMed1996

Dendrites of locus coeruleus neurons extend preferentially into two pericoerulear zones.

The intrinsic cytoarchitecture and neurochemical organization of the nucleus locus coeruleus have been characterized extensively, but there is little information about the organization of locus coeruleus neuronal processes extending outside of the nucleus proper. Light and electron microscopic immunocytochemical techniques were used to investigate the distribution of dopamine-beta-hydroxylase- or tyrosine-hydroxylase-labeled extranuclear processes in the rat pericoerulear region. The vast majority of these processes extended preferentially into two zones: (1) the pontine tegmentum medial and rostral to locus coeruleus, here termed the rostromedial pericoerulear region; and (2) a narrow region adjacent to the IVth ventricle caudomedial to locus coeruleus, designated here as the caudal juxtaependymal pericoerulear region. Far fewer labeled processes extended into the lateral and ventral pericoerulear regions. Seventy-seven percent of the labeled profiles in the pericoerulear region were dendrites. All labeled profiles in the rostromedial pericoerulear region and 94% of the labeled profiles in the caudal juxtaependymal zone were dendrites. By contrast, in the rostroventral pericoerulear region, 25% of the labeled profiles were axons. Locus coeruleus extranuclear dendrites were never presynaptic to other structures but were often contacted by several unlabeled presynaptic terminals. These results indicate that the dendrites of locus coeruleus neurons extend preferentially into two pericoerulear zones. Extranuclear dendrites in all pericoerulear regions receive extensive, nonnoradrenergic synaptic contacts. Thus, pericoerulear dendrites, particularly in the rostromedial and caudal juxtaependymal zones, are important sites for the integration of inputs to locus coeruleus neurons.

Animals↗

PubMed1985

A controlled trial of extended radical mastectomy.

One hundred twenty-three women younger than 70 years of age and at clinical Stages I or II were enrolled in a randomized clinical trial of radical versus extended radical mastectomy. The 5-year survival rates in the radical and extended radical groups were 75 +/- 6.7% and 80 +/- 6.7%, respectively. (Cox P value for comparison of survival curves = 0.32.) Of the total series, 112 were treated by the same surgeon and confirmed pathologically as having invasive mammary carcinoma. In this more homogeneous subgroup, the 5-year survival rates for the radical and extended radical groups were 71 +/- 7.6% and 85 +/- 6.2%, respectively (P = 0.09). For patients from this subgroup with central or medial tumors, the 5-year survival rates were 66 +/- 10% and 88 +/- 8.2%, respectively (P = 0.06). For patients with lateral tumors, the 5-year survival rates were nearly equal: 79 +/- 11% and 81 +/- 9.7%, respectively. The findings in a nonrandomized series of similar patients were comparable. The results are not definitive, but suggest an advantage of extended radical mastectomy over radical mastectomy for patients with central or medial tumors. Continued follow-up of the randomized series may lead to more conclusive results.

Adult↗

PubMed2000

Conformational choice at alpha,alpha-di-n-propylglycine residues: helical or fully extended structures?

The conformational analysis of peptides containing a single alpha, alpha-di-n-propylglycine (Dpg) residue incorporated into valine-rich sequences has been undertaken in order to delineate the possible role of sequence effects in stabilizing fully extended (C(5)) or local helical conformations at this residue. The three peptides Boc-Val-Dpg-Val-OMe (3), Boc-Val-Val-Dpg-Val-OMe (4), Boc-Val-Val-Dpg-Val-Val-OMe (5), have been studied by (1)H-nmr methods in chloroform (CDCl(3)) and dimethylsulfoxide (DMSO) solutions. Even in a relatively poorly solvating medium like CDCl(3), all the valine NH groups appear to be solvent-exposed, suggesting an absence of folded beta-turn conformations. However, in both CDCl(3) and DMSO the Dpg NH groups in all the three peptides appear to behave like apparently solvent-inaccessible groups. In fully extended C(5) conformations, the proximity of the NH and CO groups of Dpg may preclude effective solvation due to a combination of stereoelectronic factors. Nuclear Overhauser effects provide support for the largely extended backbones. The crystal structure of peptide 3 reveals an extended conformation at Dpg (2) with straight phi = -176 degrees, psi = 180 degrees. A correlation between the crystallographically observed backbone conformation and solution nmr parameters in DMSO has been attempted using available data. Dpg residues placed in poor helix stabilizing environments may be expected to favor a local C(5) conformation.

Amino Acid Sequence↗

PubMed2001

Extended form of a retro-inverso peptide stabilized by beta-sheet unidirectional H-bonds: Crystallographic and NMR evidence.

The crystallographic investigation of the retro-inverso peptide Bz-S-gAla-R-mAla-NHPh reveals an extended backbone conformation where the NH groups of the gem-diamino alkyl moiety and the CO groups of the malonyl residue face side by side. This extended conformation, presenting all carbonyls on opposite sides of the NH groups, is stabilized by interstrand H-bonds running in a single direction of the parallel beta-sheets that characterize the crystal packing. These sheets differ from the beta-sheets formed by native amino acids only. (1)H-NMR nuclear Overhauser effect spectroscopy (NOESY) experiments suggest that a conformation similar to that found in the crystal also prevails in dimethylsulfoxide solution. Previous potential energy calculations of gem-diamino alkyl (g) and malonyl (m) Ala residues predicted that extended forms were less stable than the helical ones because of strong electrostatic repulsions between the parallel polar groups. Similar arguments were invoked to give more weight to helical forms of the retro-peptide units in the proposal of packing models of some nylons in their crystalline polar regions. The present findings show that both g and m Ala residues can experience the extended conformation in the beta-sheet aggregation. The energy increase occurring in one strand, due to the parallel orientation of consecutive peptide dipoles, is more than compensated by favorable cooperative interactions among head-to-tail aligned peptide dipoles of facing strands, resulting in the formation of two C==O...H==N H-bonds per residue.

Alanine↗

PubMed2003

Extended versus limited lymph nodes dissection technique for adenocarcinoma of the stomach.

BACKGROUND: Surgeons disagree about the merits and risks of radical lymph node clearance during gastrectomy for cancer. OBJECTIVES: To evaluate survival and peri-operative mortality after limited or extended lymph node removal during gastrectomy for cancer. SEARCH STRATEGY: We searched MEDLINE, EMBASE, CancerLit, LILACS, Central Medical Journal Japanese Database and the Cochrane register, references from relevant articles and conference proceedings. We contacted known workers in the field. SELECTION CRITERIA: Studies published after 1970 which reported 5 year survival or postoperative mortality rates, and clearly defined the node dissection performed, were considered. We excluded studies which overtly included patients receiving perioperative chemotherapy, and comparisons with clear systematic treatment allocation bias. Randomised controlled trials (RCTs), non-randomised comparisons and observational studies were considered separately. DATA COLLECTION AND ANALYSIS: Three reviewers selected trials for inclusion. Quality assessment and data extraction were performed independently by two reviewers. Results of trials of similar design were pooled. Meta-analysis was performed separately for randomised and non-randomised comparisons. MAIN RESULTS: Two randomised and two non-randomised comparisons of limited (D1) versus extended (D2) node dissection and 11 cohort studies of either D1 or D2 resection were analysed. Meta-analysis of randomised trials did not reveal any survival benefit for extended lymph node dissection (Risk ratio = 0.95 (95% CI 0.83 - 1.09), but showed increased postoperative mortality (RR 2.23, 95% CI 1.45 - 3.45). Pre-specified subgroup analysis suggested a possible benefit in stage T3+ tumours (RR = 0.68, 95% CI 0.42-1.10). Non-randomised comparisons showed no significant survival benefit for extended dissection (RR 0.92, 95% CI 0.83 -1.02), but decreased mortality (RR 0.65, 95% CI 0.45-0.93). Subgroup analysis showed apparent benefit in UICC stage II and IIIa. Observational studies of D2 resection reported much better mortality and survival than those of D1 surgery, but the settings were strikingly different. REVIEWER'S CONCLUSIONS: D2 dissection carries increased mortality risks associated with spleen and pancreas resection, and probably with inexperience and low case volumes. Randomised studies show no evidence of overall survival benefit, but possible benefit in T3+ tumours. These results may be confounded by surgical learning curves and poor surgeon compliance. Non-randomised comparisons suggest a possible survival benefit for D2 in intermediate UICC stages. Observational studies show high 5 year survival and low operative mortality after D2 dissection in experienced units, and poor results after D1 dissection in non-specialist units. Further studies, with precautions to eliminate learning curve effects, contamination and non-compliance, are needed to evaluate D2 dissection in intermediate stage gastric cancer.

Adenocarcinoma↗

PubMed2004

Extended versus limited lymph nodes dissection technique for adenocarcinoma of the stomach.

BACKGROUND: Surgeons disagree about the merits and risks of radical lymph node clearance during gastrectomy for cancer. OBJECTIVES: To evaluate survival and peri-operative mortality after limited or extended lymph node removal during gastrectomy for cancer. SEARCH STRATEGY: We searched MEDLINE, EMBASE, CancerLit, LILACS, Central Medical Journal Japanese Database and the Cochrane register, references from relevant articles and conference proceedings. We contacted known workers in the field. SELECTION CRITERIA: Studies published after 1970 which reported 5 year survival or postoperative mortality rates, and clearly defined the node dissection performed, were considered. We excluded studies which overtly included patients receiving perioperative chemotherapy, and comparisons with clear systematic treatment allocation bias. Randomised controlled trials (RCTs), non-randomised comparisons and observational studies were considered separately. DATA COLLECTION AND ANALYSIS: Three reviewers selected trials for inclusion. Quality assessment and data extraction were performed independently by two reviewers. Results of trials of similar design were pooled. Meta-analysis was performed separately for randomised and non-randomised comparisons. MAIN RESULTS: Two randomised and two non-randomised comparisons of limited (D1) versus extended (D2) node dissection and 11 cohort studies of either D1 or D2 resection were analysed. Meta-analysis of randomised trials did not reveal any survival benefit for extended lymph node dissection (Risk ratio = 0.95 (95% CI 0.83 - 1.09), but showed increased postoperative mortality (RR 2.23, 95% CI 1.45 - 3.45). Pre-specified subgroup analysis suggested a possible benefit in stage T3+ tumours (RR = 0.68, 95% CI 0.42-1.10). Non-randomised comparisons showed no significant survival benefit for extended dissection (RR 0.92, 95% CI 0.83 -1.02), but decreased mortality (RR 0.65, 95% CI 0.45-0.93). Subgroup analysis showed apparent benefit in UICC stage II and IIIa. Observational studies of D2 resection reported much better mortality and survival than those of D1 surgery, but the settings were strikingly different. REVIEWERS' CONCLUSIONS: D2 dissection carries increased mortality risks associated with spleen and pancreas resection, and probably with inexperience and low case volumes. Randomised studies show no evidence of overall survival benefit, but possible benefit in T3+ tumours. These results may be confounded by surgical learning curves and poor surgeon compliance. Non-randomised comparisons suggest a possible survival benefit for D2 in intermediate UICC stages. Observational studies show high 5 year survival and low operative mortality after D2 dissection in experienced units, and poor results after D1 dissection in non-specialist units. Further studies, with precautions to eliminate learning curve effects, contamination and non-compliance, are needed to evaluate D2 dissection in intermediate stage gastric cancer.

Adenocarcinoma↗

PubMed2002

Novel extended tetrathiafulvalenes based on acetylenic spacers: synthesis and electronic properties.

A selection of mono- and diacetylenic dithiafulvalenes was synthesized and employed for the construction of extended tetrathiafulvalenes (TTFs) with hexa-2,4-diyne-1,6-diylidene or deca-2,4,6,8-tetrayne-1,10-diylidene spacers between the two 1,3-dithiole rings. By stepwise acetylenic scaffolding using (E)-1,2-diethynylethene (DEE) building blocks, an extended TTF containing a total of 18 C(sp) and C(sp(2)) atoms in the spacer was prepared. The versatility of the acetylenic dithiafulvene modules was also established by the efficient synthesis of a thiophene-spaced TTF, employing a palladium-catalyzed cross-coupling reaction. The developed synthetic protocols allow functionalization of the extended TTFs in three general ways: with 1) peripheral substituents on the fulvalene cores, 2) alkynyl moieties laterally appended to the spacer, and 3) cobalt clusters involving acetylenic moieties. Strong chromophoric properties of the extended TTFs were revealed by linear and nonlinear optical spectroscopies. Extensive electrochemical studies and calculations on these compounds are also reported, as well as X-ray crystallographic analyses.

Journal Article↗

PubMed1990

Extended hepatectomy for hepatocellular carcinoma.

The results of extended hepatectomy in 25 patients with hepatocellular carcinoma performed over a 16 year period have been reviewed, analysed and compared with those of 144 patients who underwent lesser liver resection. Five left and 20 right extended hepatectomies were performed for tumours ranging from 3 to 20 cm in diameter. Seventeen (68 per cent) of the patients had non-cirrhotic livers. The major postoperative complications were: haemorrhage in five cases, major bile duct injury in three, subphrenic abscess in two, liver failure in one and wound dehiscence in one. The 30-day (operative) mortality rate was 12 per cent and the median survival duration, including operative mortality, was 9.7 (range 0.2-32.1) months. The survival rate was 46 per cent at 1 year, 33 per cent at 2 years and 22 per cent at 3 years. The morbidity, mortality and survival data of extended hepatectomy were comparable with the results of lesser hepatic resections for hepatocellular carcinoma. We conclude that extended hepatectomy is a worthwhile operation for large hepatocellular carcinomas and a viable alternative to liver transplantation.

Adult↗

PubMed2003

Unusual extended fibular origin of the human soleus muscle: possible morpho-physiologic significance based on comparative anatomy.

A bilateral anomalous extended origin of the soleus muscle was observed in a 73-year-old female cadaver. It arose from the head, neck, and proximal two-thirds of the medial crest of the fibula and ran through the posterior intermuscular septum of the leg, from the lateral border of the fibula. The soleus muscle formed the vault of a muscular tunnel, overcoming the deep flexor muscles of the leg that was about 15 cm in length and directed inferiorly and laterally. The extended fibular origin delimited a blind recess lateral to the muscular tunnel and parallel to the posterior surface of the fibula. This recess measured 6.5 cm in length and extended 3.5 cm above the inferior opening of the muscular tunnel; the superior portion of the flexor hallucis longus was housed within it between the portions of the extended origin from the medial crest of the fibula and posterior intermuscular septum. The neurovascular bundle of the posterior leg coursed in the muscular tunnel. The tibial origin and calcaneal insertion of the soleus muscle were normal. Phylogenetic studies of the muscles of the lower limbs in mammals indicate that the fibular origin of soleus is more constant than the tibial origin and, in primates, the fibular origin is the only one observed in most monkeys. The case reported might be considered a conspicuous enlargement of the fibular origin observed in primates. This large fibular origin of the soleus muscle may prove to be a difficulty during surgery when accessing the proximal two-thirds of the fibula for ligation of the peroneal artery.

Aged↗

PubMed1994

Conversion from immediate-release to extended-release diltiazem in angina pectoris.

This multicenter, open-label, single crossover study examined 195 patients taking an immediate-release diltiazem tablet as chronic stable angina therapy to determine if apparently logical methods of converting them to an extended-release, once-daily formulation were effective. Patients were converted from the immediate-release (Phase I) to an extended-release (Phase II) formulation of diltiazem on a mg-for-mg basis or, when a similar dose was not available, to the next higher 120 mg dose. Weekly angina occurrences and nitroglycerin use, exercise testing at the end of each phase, and ambulatory electrocardiographic monitoring (AEM) during the week prior to the exercise study were evaluated. There was a statistically significant decrease in angina frequency and nitroglycerin consumption during Phase II. In the exercise studies, there was an insignificant increase in time to 1 mm ST-segment depression and total exercise time associated with a statistically significantly lower end-exercise blood pressure and heart rate in Phase II. In those patients who had ischemia during either phase on AEM, total ischemic duration and ischemic episodes were insignificantly lower in Phase II. All observations were similar in the subgroup of patients who were converted mg-for-mg. Adverse reactions were equal. Thus, in converting patients from an immediate- to an extended-release diltiazem formulation for the treatment of symptomatic coronary artery disease, it is reasonable to convert directly to the same or, if not available, the next higher available dose of the extended-release preparation.

Aged↗

PubMed1997

Effects of extended cold preservation and transplantation on the rat liver microcirculation.

Liver sinusoidal endothelial cell impairment and/or microcirculatory disturbances are thought to induce storage-related graft failure; however, the respective roles of changes induced by extended cold preservation and transplantation, as well as their interactions, are still unknown. To this end, the alterations of the liver microcirculation and of hepatocyte and sinusoidal endothelial cell functions induced by extended cold preservation and/or transplantation were assessed using an isolated perfused rat liver model combined to an orthotopic rat liver transplantation model. Liver microcirculation remained minimally altered following extended cold ischemia alone, despite a marked deterioration of sinusoidal endothelial cell function, while liver microcirculation alterations were mainly characterized by areas of no-reflow following transplantation alone. It was only when both procedures were associated that hepatocyte function became markedly compromised, without further deterioration in liver microcirculation. It is concluded that extended cold preservation and transplantation as such are not associated with lethal liver injury. However, the sinusoidal cell impairment and the liver microcirculatory disturbances, induced by both conditions combined, are important factors leading to secondary hepatic nonfunction, which might be triggered by extrahepatic events.

Animals↗

PubMed2006

Improving the elasticity and cytophilicity of biodegradable polyurethane by changing chain extender.

Two types of biodegradable polyurethanes (PUs) were synthesized from methylene di-p-phenyl-diisocyanate (MDI), polycaprolactone diol (PCL-diol), and chain extenders of either butanediol (BD) or 2,2'-(methylimino)diethanol (MIDE). The effects of two types of chain extenders on the degradation, mechanical properties, hydrophilicity, and cytophilicity of PUs were evaluated. In vitro degradation studies showed that PU containing MIDE has a higher degradation rate than PU synthesized using BD as a chain extender. Mechanical testing on dry and wet samples demonstrated that PU containing MIDE has a much higher elongation in the elastic region than PU containing BD. PU containing MIDE is more hydrophilic and retains more liquid during in vitro culture. Furthermore, preliminary cytocompatibility studies showed that both types of degradable PU are nontoxic, and fibroblasts adhere better and proliferate faster on MIDE containing PU than BD containing PU. To compare the cytocompatibility and degradation behaviors of the synthesized PU with existing FDA approved biocompatible material, polylactide (PLA), with a similar degradation rate, was used as negative control. Two types of PU were shown to have similar cytocompatibility and degradation behaviors as those of the PLA material. To verify the effectiveness of the cytotoxicity assay, latex was used as a positive control. Latex samples showed toxicity to cultured cells as expected. In conclusion, by changing the type of chain extender used during the synthesis of degradable PUs, the degradation rate, mechanical properties, hydrophilicity, and cytophilicity can be adjusted for different tissue engineering applications.

Absorbable Implants↗

PubMed2006

An unusual extended DNA loop attachment region is located in the human dystrophin gene.

We have found and characterized an unusual extended area of DNA association with the nuclear matrix in the human dystrophin gene. This extended DNA loop anchorage region (LAR) has been mapped and characterized using a variety of biochemical and microscopy techniques. It spans approximately 200 kbp at chromosomal locations 950-1,150 Kb downstream to the beginning of the first exon of the dystrophin gene Dp427m and covers a part of the intron 43, exon 44, and most of intron 44. The extended LAR harbors the major recombination hot spot of the dystrophin gene and a replication origin. We propose a model where DNA topoisomerase II-mediated cleavage at the nuclear matrix may enhance recombination events within this extended LAR.

Chromosome Mapping↗

PubMed2000

TNF-alpha release by monocytic THP-1 cells through cross-linking of the extended V-region of the oral streptococcal protein I/II.

We tested the hypothesis of a conserved activation mode of monocytic THP-1 cells by proteins I/II expressed by several species of oral streptococci through the specific role of the extended V-region. We studied the binding and modulating activities of six proteins I/II purified from strains representing four different species of oral streptococci, and of expression products of polymerase chain reaction-amplified sequences encoding corresponding extended V-regions. We found that the different proteins I/II bound to THP-1 cells in a sugar-dependent mode involving the extended V-region. Furthermore, all the proteins I/II stimulated THP-1 cells to produce tumor necrosis factor alpha, indicating that these properties are not strain- or species-specific. Despite the weak stimulation of THP-1 cells by the extended V-region alone, we obtained evidence that cross-linking of this region can be one of the mechanisms involved in monocytic cell activation by proteins I/II.

Amino Acid Sequence↗

PubMed2004

Postoperative pulmonary complications are associated with worse short- and long-term outcomes after extended esophagectomy.

BACKGROUND: Risk analysis of pulmonary complications after extended esophagectomy with three-field lymph node dissection (3FLND) has been little reported in the literature. METHODS: Risk factors of developing postoperative pneumonia after extended esophagectomy and its effects on in-hospital death and overall long-term survival were compared between 38 patients who developed pneumonia and 80 patients who did not. RESULTS: Eight patients died of postoperative complications during the hospital stay after esophagectomy. Seven of those 8 patients developed pneumonia, whereas 31 patients of 110 patients who were discharged from the hospital developed pneumonia (P < 0.01). Pneumonia occurred more frequently in elderly patients (P < 0.01), in heavy smokers (P < 0.05), in patients with preoperative pulmonary obstructive dysfunction (P < 0.05), and in patients who received 3 U or more perioperative blood transfusion (P < 0.05). Five-year overall survival rate (26.7%) of 38 patients who developed pneumonia was significantly worse than 53.4% who did not develop pneumonia (P < 0.01). Multivariate analysis of prognostic factors for overall survival showed that pathological tumor stage (hazard ratio 5.380, P < 0.01) and pneumonia (hazard ratio 2.369, P < 0.01) were independent risk factors. Postoperative pneumonia is correlated with in-hospital death and poorer long-term survival after extended esophagectomy with 3FLND. CONCLUSIONS: Elderly patients with a history of heavy smoking and poor pulmonary function should be regarded as a high-risk group of patients for developing pneumonia and very careful selection is required before subjecting such patients to extended esophagectomy.

Aged↗

PubMed2007

Extended right trisegmentectomy using in situ hypothermic perfusion with modified HTK solution for a large intrahepatic cholangiocarcinoma.

The technique of right hepatic trisegmentectomy has been standardized for large tumors that involve the right lobe and extend into the medial segment of the left lobe. However, these tumors are deemed unresectable if they encroach across the falciform ligament into the left lateral segment. We report the technique of extended right trisegmentectomy in a patient with a large intrahepatic cholangiocarcinoma that involved the right lobe of the liver and extended into the medial and lateral segments of the left lobe. The resection was performed by using total hepatic vascular isolation and in situ hypothermic perfusion with modified histidine-tryptophan-ketoglutarate (HTK) solution into the left lateral segment. The biliary enteric anastomosis was constructed using a double hepaticojejunostomy to Segments II and III bile ducts. The procedure allowed safe parenchymal dissection with preservation of the blood supply to Segments II and III. Furthermore, in situ hypothermic perfusion protected the remnant liver from the deleterious effects of warm ischemia during parenchymal dissection and facilitated postoperative recovery. To the best of our knowledge, this is the first report of extended right trisegmentectomy for the treatment of intrahepatic cholangiocarcinoma in the Western literature.

Bile Duct Neoplasms↗

PubMed1990

Extended neck dissection.

From the time Crile described radical neck dissection in 1906, this surgical procedure became popular in the management of metastatic cancer in the neck. Over the past two decades, the modified neck dissection has been effectively utilized for conservation of function and cosmesis while achieving the same oncologic goals. However, there are several instances where the above standard procedures are not adequate for resection of malignant tumors. Although there is a definite trend toward conservation procedures, extended neck dissection is often necessary especially in patients with N2 and N3 disease. Apart from the standard structures removed in radical neck dissection, the other structures removed in extended neck dissection include skin, the digastric muscle, hypoglossal nerve, vagus nerve, sympathetic chain, ramus mandibularis, carotid artery, tracheo-esophageal nodes, etc. Over the past seven years, we have performed 40 extended neck dissections. All the patients had N2 or N3 disease in the neck. Nine patients had unknown primaries. Thirteen patients had their primary tumors in the oral cavity and 11 in the laryngopharynx. Five patients had primary tumor in the salivary glands and two patients had metastatic melanoma. Patients who underwent extensive skin excision had pectoralis myocutaneous flap reconstruction. All patients received postoperative radiation therapy. One patient died of cardiac problems 4 weeks after operation. Local control was achieved in 70%. The most difficult region for local control was the disease behind the mastoid process, and the most difficult problems were patients with involvement of the subdermal lymphatics. Our data suggests that there are definite situations where extended neck dissection is indicated with satisfactory local control of the nodal disease.

Adult↗

PubMed2002

Evaluation of pulse-duration on purpuric threshold using extended pulse pulsed dye laser (cynosure V-star).

BACKGROUND AND OBJECTIVES: Pulsed dye lasers (PDL) with extended pulse-durations create new opportunities in the treatment of vascular lesions. Development of extended pulse methods requires understanding of tissue effects of extended pulse-durations. We evaluated tissue effects of extended pulse-duration PDL (EPDL) with cooling. Effects of increasing pulse-duration, fluence, and multiple passes were evaluated to determine purpuric threshold and delayed purpuric response. STUDY DESIGN/PATIENTS AND METHODS: Ten patients were treated with EPDL and air-cooling on normal buttocks skin. Exposure pulse-durations of 0.5, 2, 20, and 40 milliseconds and increasing fluences 3-20 J/cm(2), pulse-duration dependent. Exposures were evaluated 0.5, 1, and 24 or 48 hours determining purpuric threshold and side effects. RESULTS: Immediate purpuric threshold increased from 6.2 to 8, 10.4, and 13.8 J/cm(2) at pulse-durations of 0.5, 2, 20, and 40 milliseconds, respectively. Purpuric threshold dropped after 24 hours to 5.2, 7.1, 9.3, and 11.9 J/cm(2), respectively. Multi-pass treatment lowered purpuric threshold by 1 J/cm(2). EPDL purpura resolved in less time than traditional PDL. No side effects were noted. CONCLUSIONS: EPDL exhibits increasing purpuric threshold with increasing pulse-durations, and risk of delayed onset of purpura.

Drug Administration Schedule↗