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PubMed1998

The effect of partial excision of the A2 and A4 pulleys on the biomechanics of finger flexion.

The purpose of this study was to investigate the effect of partial excision of the A2 and A4 pulleys on digital angular rotation and the energy required to flex the finger. Partial excision of A2 resulted in a statistically significant decrease in angular rotation of 3 and 5% after 50 and 75% excision, respectively. Partial excision of A4 failed to produce any significant differences in angular rotation. Combined partial excision of A2 and A4 resulted in a significant decrease of 5 and 8% after 50 and 75% excision, respectively. Significant differences in work of flexion occurred only after excision of 75% of the A2 pulley. Although optimal finger function relies on the integrity of the A2 and A4 pulleys which maintain the efficiency of the digital flexor system, these data suggest that 25% of the A2 pulley, up to 75% of the A4 and 25% of the A2 and A4 together can be excised without significant effects on angular rotation.

Biomechanical Phenomena↗

PubMed1998

Cre/loxP-mediated in vivo excision of large segments from yeast genome and their amplification based on the 2microm plasmid-derived system.

In vivo excision and amplification of pre-determined, large genomic segments, directly from the genome of a natural host, provides an alternative to conventional cloning in foreign vectors. Using this approach, we have devised an in vivo procedure for excising large segments of Saccharomyces cerevisiae genome using Cre/loxP system of bacteriophage P1, followed by amplification of excised circles, as based on the yeast 2microm plasmid-derived ori and Flp/FRT machinery. To provide the excision and replication enzymes, trans-acting genes cre and FLP, which were under a very tight control of GAL1 and GAL10 promoters, respectively, were inserted by homologous recombination into the URA3 gene on chromosome V. Two parallel loxP sequences, which serve as the recognition sites for the Cre recombinase, were also integrated into the genome at pre-determined sites that are 50-100kb apart. Moreover, 2microm ori, REP3 and two inverted FRTs, which serve as a conditional replication system, were also integrated between the loxP sites. The strain carrying all these inserted elements was perfectly stable. Only after the induction by galactose of the Cre excision function, the genomic segment flanked by two loxP sites was excised and circularized. Applying this procedure, the 50-kb LEU2-YCR011c and 100-kb LEU2-YCR035c regions of chromosome III were successfully excised from the S. cerevisiae genome, whereas the 2microm ori, as aided by FRT/Flp, provided the amplification function. Such excised and amplified genomic segments can be used for the sequencing and functional analysis of any yeast genes.

Chromosomes↗

PubMed2003

Nucleotide excision repair from site-specifically platinum-modified nucleosomes.

Nucleotide excision repair is a major cellular defense mechanism against the toxic effects of the anticancer drug cisplatin and other platinum-based chemotherapeutic agents. In this study, mononucleosomes were prepared containing either a site-specific cis-diammineplatinum(II)-DNA intrastrand d(GpG) or a d(GpTpG) cross-link. The ability of the histone core to modulate the excision of these defined platinum adducts was investigated as a model for exploring the cellular response to platinum-DNA adducts in chromatin. Comparison of the extent of repair by mammalian cell extracts of free and nucleosomal DNA containing the same platinum-DNA adduct reveals that the nucleosome significantly inhibits nucleotide excision repair. With the GTG-Pt DNA substrate, the nucleosome inhibits excision to about 10% of the level observed with free DNA, whereas with the less efficient GG-Pt DNA substrate the nucleosome inhibited excision to about 30% of the level observed with free DNA. The effects of post-translational modification of histones on excision of platinum damage from nucleosomes were investigated by comparing native and recombinant nucleosomes containing the same intrastrand d(GpTpG) cross-link. Excision from native nucleosomal DNA is approximately 2-fold higher than the level observed with recombinant material. This result reveals that post-translational modification of histones can modulate nucleotide excision repair from damaged chromatin. The in vitro system established in this study will facilitate the investigation of platinum-DNA damage by DNA repair processes and help elucidate the role of specific post-translational modification in NER of platinum-DNA adducts at the physiologically relevant nucleosome level.

Animals↗

PubMed2004

Mouse NEIL1 protein is specific for excision of 2,6-diamino-4-hydroxy-5-formamidopyrimidine and 4,6-diamino-5-formamidopyrimidine from oxidatively damaged DNA.

A functional homologue of human DNA glycosylase NEIL1 (hNEIL1) in mouse has recently been cloned, isolated, characterized, and named mouse NEIL1 (mNEIL1). This enzyme exhibited specificity for excision of oxidatively modified pyrimidine bases such as thymine glycol, 5,6-dihydrouracil, and 5-hydroxypyrimidines, using oligonucleotides with a single base lesion incorporated at a specific site. It also acted upon AP sites; however, no significant excision of 8-hydroxyguanine was observed [Rosenquist, T. A., Zaika, E., Fernandes, A. S., Zharkov, D. O., Miller, H., and Grollman, A. P. (2003) DNA Repair 2, 581-591]. We investigated the substrate specificity and excision kinetics of mNEIL1 for excision of oxidatively modified bases from high-molecular weight DNA with multiple lesions, which were generated by exposure of DNA in aqueous solution to ionizing radiation. Among a large number of pyrimidine- and purine-derived lesions detected and quantified in DNA, only purine-derived lesions 2,6-diamino-4-hydroxy-5-formamidopyrimidine and 4,6-diamino-5-formamidopyrimidine were significantly excised. This finding establishes that mNEIL1 and its functional homologue hNEIL1 possess common substrates, namely, 2,6-diamino-4-hydroxy-5-formamidopyrimidine and 4,6-diamino-5-formamidopyrimidine. Measurement of excision kinetics showed that mNEIL1 possesses equal specificity for these two formamidopyrimidines. This enzyme also excised thymine-derived lesions thymine glycol and 5-hydroxy-5-methylhydantoin, albeit at a much lower rate. A comparison of the specificity and excision kinetics of mNEIL1 with other DNA glycosylases shows that this enzyme is as efficient as those DNA glycosylases, which specifically remove the formamidopyrimidines from DNA.

Animals↗

PubMed2007

3'-Azido-3'-deoxythymidine-(5')-tetraphospho-(5')-adenosine, the product of ATP-mediated excision of chain-terminating AZTMP, is a potent chain-terminating substrate for HIV-1 reverse transcriptase.

The resistance of HIV-1 to 3'-azido-3'-deoxythymidine (AZT) involves phosphorolytic excision of chain-terminating AZT-5'-monophosphate (AZTMP). Both pyrophosphate (PPi) and ATP act as excision substrates in vitro, but the intracellular substrate used during replication of AZT-resistant HIV is still unknown. PPi-mediated excision produces AZT-5'-triphosphate (AZTTP), which could be immediately re-used as a substrate for viral DNA chain termination. In contrast, ATP-mediated excision produces the novel compound AZT-(5')-tetraphospho-(5')-adenosine (AZTp4A). Since little is known of the interaction of AZTp4A with HIV-1 RT, we carried out kinetic and molecular modeling studies to probe this. AZTp4A was found to be a potent inhibitor of HIV-1 RT-catalyzed DNA synthesis and of both ATP- and PPi-mediated AZTMP excision. AZTp4A is in fact an excellent chain-terminating substrate for AZT-resistant RT-catalyzed DNA synthesis, better than AZTTP (k(pol)/Kd = 6.2 and 11.9 for AZTTP and AZTp4A, respectively). The affinity of AZT-resistant HIV-1 RT for AZTp4A is at least 30,000-fold greater than that for the excision substrate ATP and approximately 10-fold greater than that for AZTTP. Dissociation of newly formed AZTp4A from RT may therefore provide a significant rate-limiting step for continued HIV-1 DNA synthesis. Our studies show that the products of PPi- and ATP-mediated excision of chain-terminating AZTMP (AZTTP and AZTp4A, respectively) are both potent chain-terminating substrates for HIV-1 RT, suggesting that there is no obvious benefit to HIV using ATP instead of PPi as the excision substrate.

Adenosine Triphosphate↗

PubMed2003

The potential impact on melanoma mortality of reducing rates of suboptimal excision margins.

We estimated the potential benefit of reducing rates of inadequate excision margins in the treatment of localized invasive melanoma. A computer-simulated Markov decision analytic model was created to follow until death a hypothetical cohort of 55 y old Caucasians, newly diagnosed in a community setting with localized invasive melanoma. We considered two scenarios: usual care, and a hypothetical intervention. Markov states included well without local recurrence, local recurrence, cured, and dead. Published population-based data were used for rates of optimal excision margins, local recurrence, and mortality. Two outcome measures were employed: melanoma-related mortality and life expectancy. Major assumptions included: local recurrence occurs within 10 y of diagnosis, and patients revert to general population mortality rates 10 y following melanoma excision or subsequent local recurrence. For usual care, the model estimated 8.17% melanoma-related mortality. Modeling intervention with 100% optimal excision margins reduced this rate to 6.15%, a 25% relative reduction in mortality. This increased average life expectancy by 0.437 y, which equates to approximately 11 additional years in the 4% who would not experience a local recurrence due to improved excision margins. Increasing the percentage of optimal excision margins to 80% would still yield substantial improvement, with 6.83% melanoma-related mortality, saving 0.29 life-years compared with baseline. Results were insensitive to moderate changes in the parameter values. Suboptimal excision margins may account for approximately one-fourth of all melanoma-related mortality for localized invasive melanoma. If intervention can achieve even modest adherence to optimal excision margins, it might substantially reduce mortality.

Cohort Studies↗

PubMed2003

Biomechanical evaluation of flexor tendon function after hamate hook excision.

PURPOSE: Hamate hook fractures are uncommon injuries for which treatment is controversial. Excision of the hamate hook is considered to be the preferred method of treatment but the effects of hamate excision are not clearly delineated. The purpose of this study was to determine what effect, if any, excision of the hamate has on flexor tendon function. METHOD: The biomechanical effects of hamate hook excision on flexor tendon function were studied in fresh cadaveric forearm specimens with wrists fixed in 3 positions (neutral, 30 degrees extension, 30 degrees extension with 30 degrees ulnar deviation). Flexor tendon force, flexor tendon excursion, and flexor tendon shift were evaluated. RESULTS: Flexor tendon force decreased after hamate hook excision (11% in neutral, 14% in 30 degrees extension, and 15% in 30 degrees extension with 30 degrees ulnar deviation). The flexor profundus tendons had a 7- to 11-mm increase in proximal tendon excursion after hamate hook excision depending on the position of the wrist, and the flexor profundus tendons of the small finger shifted 4 to 5 mm in ulnar direction. CONCLUSIONS: The hamate hook provides some biomechanical advantage for flexor tendon function and cadaveric changes in tendon force after its excision suggest that power grip may be decreased after hamate hook excision.

Biomechanical Phenomena↗

PubMed2000

Chronic axillary hidradenitis--the efficacy of wide excision and flap coverage.

A number of different modalities of surgical treatment for axillary hidradenitis suppurativa have been suggested. This study compares three different methods of surgical excision. Fifty-nine patients (94 axillae) were treated over a 14-year period. There were 42 females and 17 males with an average age of 32 years (range 16-65 years). Twenty-six axillae had excision of only the diseased skin and recurrent disease occurred in seven. However, in 39 axillae that were treated by excision of all the hair bearing skin, only three developed recurrent disease, which is a significant reduction in the incidence of recurrent disease (P = 0.04, Fischer's exact test). Twenty-nine axillae were treated by wide local excision (2 cm beyond the hair bearing skin) and no recurrence occurred. However, there was no statistical difference (P = 0.18, Fischer's exact test) in disease recurrence between excision of all the hair bearing skin and wide local excision. This study suggests that excision of all the hair bearing skin is the preferred method of surgical treatment. Flap coverage was an effective method to achieve wound closure after adequate excision and can be achieved by random fasciocutaneous flaps for small or medium sized defects and parascapular flaps for large defects.

Adolescent↗

PubMed2002

A follow-up study to investigate the efficacy of initial treatment of lentigo maligna with surgical excision.

Recurrence rates following conventional surgery for lentigo maligna (LM) are reported to be between 7% and 15%. However, the studies are few, contain small numbers of patients and have relatively short follow-up. The principle aim of this study was to determine the efficacy of conventional surgery for LM in a large unbiased sample of all LM presenting in a defined geographical area. All LM cases occurring in Leicestershire between 1987 and 1996 were identified. Data were gathered from case notes, general practitioners and the Office for National Statistics (for any mortality data) and patients were invited to attend for examination. There were 89 evaluable patients treated with primary excision, representing the largest reported series to date. There was a false positive rate for diagnostic biopsy for LM (when the correct diagnosis was lentigo maligna melanoma, LMM) of 5% (95% confidence interval, CI: 1% to 14%). The initial excision was histologically incomplete in 9% (4% to 17%) of cases. In completely excised lesions (n=81) the observed recurrence rate was 20% (CI: 12% to 30%) at a mean follow-up of 42 months, which is similar to previous reports. However, Kaplan-Meier analysis yielded an estimated probability of recurrence of 31% (CI: 19% to 50%); time to relapse was up to 66 months. The age and sex of the patient and the site of the lesion were not associated with outcome, but, surprisingly, smaller lesions were associated with incomplete excision and recurrence. Fifteen current lesions were excised with similar success rates: the incomplete re-excision rate was 7% (CI: 0.2% to 32%) and the recurrence rate was 31% (CI: 12% to 83%) at 28 months. The estimated rate of transformation to LMM after initial surgical treatment was 1.5% (CI: 0.3% to 8%), and LMM was not the cause of death in any patient. These recurrence rates following complete primary excision and re-excision following recurrence were high compared with general expectations, which is largely the result of the method of analysis and the long follow-up. The high rate calls into question the accuracy of the routine histological assessment of clearance. The development of LMM was rare following surgery.

Adult↗

PubMed2000

[Clinical and histologic features of 141 primary basal cell carcinomas of the periocular region and their rate of recurrence after surgical excision].

BACKGROUND: The aim of this study was to assess clinical and histologic features of primary basal cell carcinomas of the periocular region and to calculate the rate of recurrence of these tumors after surgical excision without intraoperative frozen section control. METHODS: All primary basal cell carcinomas of the periocular region which were treated by surgical excision at the University Eye Hospital and Clinic of Ulm between 1993 and 1998 were reviewed and special attention was paid to age and sex of the patient and localization and histology of the tumor. The recurrence rates were calculated depending on whether the margins were free or involved on histologic examination of the excised specimens. RESULTS: We could include 137 patients with 141 tumors into this study. In 92 patients with 95 tumors, follow-up data of at least 3 months was available with a mean follow-up period of 31.3 months. The mean age of the patients was 68.9 years, range 28.7-91.3 years. The tumor was located at the lower eyelid, medial canthus, upper eyelid and lateral canthus in 63.1%, 29.8%, 5.7% and 1.4%, respectively. The solid (53.9%) and the solid-cystic (17.7%) type were the most common encountered histology followed by the mixed type with sclerosing foci (12.1%) and the morphea or sclerosing type (10.6%). A free margin on histologic examination was achieved in only 47.6% of cases. The overall recurrence rate was 9.5% [definite recurrences: 6 cases (6.3%); questionable recurrences: 3 cases (3.2%)]. With histologically complete excision the recurrence rate was only 2.3% (1 case) and in the case of an incomplete excision definite recurrent tumors were observed in 11.8% (6 cases) and questionable recurrences in 3.9% (2 cases) of cases during the follow-up period. CONCLUSIONS: Surgical excision of basal cell carcinomas of the periocular region without utilizing intraoperative frozen section control or Mohs' micrographic surgery is associated with a high rate of positive tumor margin on histologic examination. However, our study showed that this is only infrequently followed by local recurrences. This result may raise the question whether simple surgical excision is still an option in the case that more cumbersome methods such as Mohs' micrographic surgery or intraoperative frozen section control are not available. However, with positive tumor margin on histologic examination of the excised tissue or with the presence of a sclerosing type regular follow-up is mandatory.

Adult↗

PubMed2000

The effects of loop excision of the transformation zone on cervical length: implications for pregnancy.

OBJECTIVE: This study was undertaken to determine whether previously described significant and quantitative cervical shortening caused by loop excision of the transformation zone persists after 3 months of healing. STUDY DESIGN: A prospective study was designed in which 20 patients were enrolled. Each underwent transvaginal ultrasonography for determination of cervical length before the loop excision of the transformation zone and >/=3 months after the loop excision of the transformation zone. Simple regression analysis and the Student paired t test was performed to determine whether the length of the cervix had changed significantly between the measurements. RESULTS: The mean cervical lengths as measured by transvaginal ultrasonography before and after loop excision of the transformation zone were 3.1 +/- 0.8 cm and 3.1 +/- 0.7 cm, respectively. The correlation between ultrasonographic measurements before and after loop excision of the transformation zone was r = 0.88 (P <.0001). A paired t test resulted in a P value of 1.0000, which indicates that the ultrasonographic measurement after loop excision of the transformation zone was not different from the ultrasonographic measurement before loop excision of the transformation zone. The mean difference between measurements was 0.0 +/- 0.4 cm. CONCLUSION: After adequate healing time after loop excision of the transformation zone, the length of the cervix, as measured by transvaginal ultrasonography, does not appear to remain shortened.

Cervix Uteri↗

PubMed1992

Control of excision frequency of maize transposable element Ds in Petunia protoplasts.

The complete coding region of maize transposable element Ac and truncated but active derivatives of it were placed under the control of promoters of different strength and tested for the ability to excise transposable element Ds from a beta-glucuronidase reporter gene in a cotransfection assay in Petunia protoplasts. The highest excision values (5% of the protoplasts able to express the beta-glucuronidase gene in a control experiment) were observed with a truncated version of the Ac coding region under the control of the 2' promoter. The weak Ac promoter is sufficient to give rise to excision values not much lower than those found with much stronger promoters such as the 2' and nos promoters. A decrease in excision frequency was observed when translation of the Ac coding region was hindered by out-of-frame ATG codons in addition to the use of weak promoters. Increasing the level of Ac transposase thus does not seem to be sufficient to raise the level of Ds excision observed in this system and possibly also in maize. Therefore another factor limits the excision of Ds elements. Previously, it was reported that in tobacco cells the deletion of Ds sequence between base pairs 186 and 245 led to a decrease of the Ds excision frequency by the full-length but not by the truncated Ac product. In the Petunia assay system, however, deletion of these sequences decreased the excision rate with both the full length and the truncated Ac coding region. A cDNA construct was found similarly active as the corresponding genomic DNA.

Journal Article↗

PubMed1992

Transposon Tn5 excision in yeast: influence of DNA polymerases alpha, delta, and epsilon and repair genes.

Interaction between short repeats may be a source of genomic rearrangements and deletions. We investigated possible interactions between short (9 base pairs) direct repeats in yeast by using our previously described system for analyzing bacterial transposon Tn5 excision in yeast. Mutations of either POL3 or POL1, the proposed structural genes for polymerases delta and alpha, respectively, yield high levels of excision at semipermissive temperatures. pol2 (corresponding to polymerase epsilon) and pol2 pol3 double mutants do not exhibit enhanced excision. A majority of excision events involve direct repeats and are precise; the remaining imprecise excisions occur within or in the vicinity of the repeats. The three DNA repair pathways identified by rad1, rad6 and rad18, rad50 and rad52 mutations were examined for their possible role in Tn5 excision; no enhancement was observed in mutants. However, the pol3-stimulated Tn5 excision was reduced in rad52 and rad50 mutants. This suggests the potential for interaction between the systems for DNA double-strand break/recombinational repair and DNA synthesis. Based on the suggestion of Morrison et al. [Morrison, A., Araki, H., Clark, A. B., Hamatake, R. H. & Sugino, A. (1990) Cell 62, 1143-1151] that polymerases delta and alpha are responsible for lagging-strand synthesis and that polymerase epsilon is responsible for leading-strand synthesis, we suggest that Tn5 excision is stimulated under conditions of altered lagging-strand synthesis, possibly due to extended opportunities for single-strand interactions between the inverted insertion sequence I550 repeats of Tn5.

Base Sequence↗

PubMed2004

Differential requirement for proliferating cell nuclear antigen in 5' and 3' nick-directed excision in human mismatch repair.

Proliferating cell nuclear antigen (PCNA) is involved in mammalian mismatch repair at a step prior to or at mismatch excision, but the molecular mechanism of this process is not fully understood. To examine the role of PCNA in mismatch-provoked and nick-directed excision, orientation-specific mismatch removal of heteroduplexes with a pre-existing nick was monitored in human nuclear extracts supplemented with the PCNA inhibitor protein p21. We show here that, whereas 3' nick-directed mismatch excision was completely inhibited by low concentrations of p21 or a p21 C-terminal fusion protein, 5' nick-directed excision was only partially blocked under the same conditions. No further reduction of the 5' excision was detected when a much higher concentration of p21 C-terminal protein was used. These results suggest the following. (i) There is a differential requirement for PCNA in 3' and 5' nick-directed excision; and (ii) 5' nick-directed excision is conducted by a manner either dependent on or independent of PCNA. Our in vitro reconstitution experiments indeed identified a 5' nick-directed excision pathway that is dependent on PCNA, hMutSalpha, and a partially purified fraction from a HeLa nuclear extract.

Adenosine Triphosphatases↗

PubMed1994

Centrin plays an essential role in microtubule severing during flagellar excision in Chlamydomonas reinhardtii.

Previously, we reported that flagellar excision in Chlamydomonas reinhardtii is mediated by an active process whereby microtubules are severed at select sites within the flagellar-basal body transition zone (Sanders, M. A., and J. L. Salisbury. 1989. J. Cell Biol. 108:1751-1760). At the time of flagellar excision, stellate fibers of the transition zone contract and displace the microtubule doublets of the axoneme inward. The resulting shear force and torsional load generated during inward displacement leads to microtubule severing immediately distal to the central cylinder of the transition zone. In this study, we have used a detergent-extracted cell model of Chlamydomonas that allows direct experimental access to the molecular machinery responsible for microtubule severing without the impediment of the plasma membrane. We present four independent lines of experimental evidence for the essential involvement of centrin-based stellate fibers of the transition zone in the process of flagellar excision: (a) Detergent-extracted cell models excise their flagella in response to elevated, yet physiological, levels of free calcium. (b) Extraction of cell models with buffers containing the divalent cation chelator EDTA leads to the disassembly of centrin-based fibers and to the disruption of transition zone stellate fiber structure. This treatment results in a complete loss of flagellar excision competence. (c) Three separate anti-centrin monoclonal antibody preparations, which localize to the stellate fibers of the transition zone, specifically inhibit contraction of the stellate fibers and block calcium-induced flagellar excision, while control antibodies have no inhibitory effect. Finally, (d) cells of the centrin mutant vfl-2 (Taillon, B., S. Adler, J. Suhan, and J. Jarvik. 1992. J. Cell Biol. 119:1613-1624) fail to actively excise their flagella following pH shock in living cells or calcium treatment of detergent-extracted cell models. Taken together, these observations demonstrate that centrin-based fiber contraction plays a fundamental role in microtubule severing at the time of flagellar excision in Chlamydomonas.

Animals↗

PubMed1999

Long-term follow-up of patients with rectal cancer managed by local excision with and without adjuvant irradiation.

OBJECTIVE: The long-term outcomes of patients undergoing local excision with or without pelvic irradiation were examined to define the role of adjuvant irradiation after local excision of T1 and T2 rectal cancers. METHODS: Ninety-nine patients with T1 or T2 rectal cancers underwent local excision with or without adjuvant irradiation at Massachusetts General Hospital and Emory University Hospital between January 1966 and January 1997. Of these, 52 patients were treated by local excision alone and 47 patients by local excision plus adjuvant irradiation. Twenty-six of these 47 patients were treated by irradiation in combination with 5-fluorouracil chemotherapy. The outcomes of these groups were compared. RESULTS: The 5-year actuarial local control and recurrence-free survival rates were 72% and 66%, respectively, for the local excision alone group and 90% and 74%, respectively, for the adjuvant irradiation group. This improvement in outcome was evident despite the presence of a higher-risk patient population in the adjuvant irradiation group. Adverse pathologic features such as poorly differentiated histology and lymphatic or blood vessel invasion decreased local control and recurrence-free survival rates in the local excision only group. Adjuvant irradiation significantly improved 5-year outcomes in patients with high-risk pathologic features. Four cases of late local recurrence were seen at 64, 72, 86, and 91 months in the adjuvant irradiation group. CONCLUSIONS: The authors recommend adjuvant chemoradiation for all patients undergoing local excision for T2 tumors, and for T1 tumors with high-risk pathologic features. The four cases of late local failures beyond 5 years in the adjuvant irradiation group underscores the need for careful long-term follow-up in these patients.

Actuarial Analysis↗

PubMed1983

The effect of topical epinephrine hydrochloride in saline on blood loss following tangential excision of burn wounds.

Burn wounds that were excised tangentially in the first 21 days after the burn were dressed immediately following excision with either saline or epinephrine hydrochloride-saline compresses (30 mg in 1030 ml normal saline) that were then left for 30 minutes while skin was harvested and banked. Thereafter, saline compresses were applied to all patients' wounds and changed every 4 hours. Banked skin grafts were applied without the need of a second general anesthetic on the first postoperative day. In both groups of patients, blood loss exceeded 9 percent of the calculated blood volume for each 1 percent of the body surface excised (this included blood loss due to harvest of skin graft necessary to cover the excised wounds) when the excision was performed in the first 14 days after the burn. Addition of epinephrine did not reduce net blood loss. Premature ventricular contractions were not observed, although 2 of 29 patients had an elevation in pulse rate of 25 beats per minute or more. No factors were identified that would reduce the blood loss following early tangential burn excision. Before embarking on tangential excision in the early postburn period, one must be prepared to replace 10 percent of the circulating blood volume for each 1 percent of the body surface to be excised.

Administration, Topical↗

PubMed1997

Patterns of excision and referral from primary care of melanocytic lesions.

There is debate about the margin of normal tissue that should be included with excisions of melanocytic lesions of the skin, and about which lesions should be referred for specialist care. We describe the determinants of the margins of excised melanocytic skin lesions and of referral patterns from primary care. Copies of the pathology reports of melanocytic skin lesions excised from two cities in tropical Queensland were obtained; questionnaires about each lesion were administered to the excising doctor. Data about 3275 lesions (2914 naevi, 130 lentigos, 151 melanomas, 51 dysplastic naevi, 21 Hutchinson's melanotic freckles and eight other melanocytic lesions) were analysed. Twenty-one per cent of the treatment sessions involved the excision of more than one lesion; 5% involved three lesions or more. Most lesions were managed by one doctor. The overall mean margin of excision was 2.8 mm. It was greater for longer qualified doctors, surgeons and college-affiliated general practitioners, for lesions excised to address malignancy (3.0 mm) rather than cosmetic appearance (2.4 mm), for Hutchinson's melanotic freckles (5.9 mm) and melanomas (5.1 mm) compared with benign lesions (2.7 mm) (P < 0.001) and for older patients (2.6 mm for those < or = 15, 3.5 mm for those > 40 years) (P = 0.001). Wider excisions of skin melanocytic lesions are performed by older and more experienced doctors, on older patients, and for lesions in which malignancy is being addressed.

Adolescent↗