The consistent presence of the human accessory deep peroneal nerve. (1/777)

Twenty-four human legs were dissected macroscopically to study the morphological details of the accessory deep peroneal nerve. This nerve arose from the superficial peroneal nerve and descended in the lateral compartment of the leg, deep to peroneus longus along the posterior border of peroneus brevis. Approaching the ankle joint, this nerve passed through the peroneal tunnels to wind around the lateral malleolus; it then crossed beneath the peroneus brevis tendon anteriorly to reach the dorsum of the foot. The accessory deep peroneal nerve was found in every case examined and constantly gave off muscular branches to peroneus brevis and sensory branches to the ankle region. In addition, this nerve occasionally had muscular branches to peroneus longus and extensor digitorum brevis, and sensory branches to the fibula and the foot. The anomalous muscles around the lateral malleolus were also innervated by this nerve. Neither cutaneous branches nor communicating branches with other nerves were found. The present study reveals that the accessory deep peroneal nerve is consistently present and possesses a proper motor and sensory distribution in the lateral region of the leg and ankle. It is not an anomalous nerve as has previously been suggested.  (+info)

Microdissection-based analysis of mature ovarian teratoma. (2/777)

The genotypic features of mature ovarian teratomas (MOTs) are controversial. Early studies detected a homozygous genotype in MOTs suggesting that these tumors are composed of germ cells that have undergone meiosis I. Other studies, however, revealed a heterozygous genotype in a substantial proportion of MOTs suggesting an origin either from premeiotic germ cells or from a somatic cell line. In view of the complex morphology of MOTs and to increase the sensitivity of teratoma genotyping, we applied tissue microdissection before genetic analysis of teratomatous tissue. This approach allowed selective analysis of different heterotopic tissue elements as well as the lymphoid tissues within MOTs the origin of which is unknown. After DNA extraction, the tissue samples were polymerase chain reaction amplified using a random panel of highly informative genetic markers for different chromosomes to evaluate heterozygosity versus homozygosity. In all seven cases that were analyzed, heterotopic tissues consistently revealed a homozygous genotype with several markers; in two cases, heterozygosity was detected with a single marker, indicating a meiotic recombination event. Lymphoid aggregates within MOTs were heterozygous and derived from host tissue rather than from teratomatous growth. However, well differentiated thymic tissue was consistently homozygous, suggesting lymphoid differentiation capability of MOTs. We conclude that potential pitfalls in genotyping of teratomas including meiotic recombination and host cell participation can be avoided by a microdissection-based approach in combination with a panel of genetic markers.  (+info)

The possibility of deep peroneal nerve neurotisation by the superficial peroneal nerve: an anatomical approach. (3/777)

Neurotisation involves transfer of nerves for the restoration of function following injury. A number of nerves have been used in different part of the peripheral nervous system. This study was undertaken to develop a practical and relatively safe surgical approach to the treatment of L4 root lesion's. We examined the effectiveness and safety of neurotisation of the deep peroneal nerve and its branches by the superficial peroneal nerve. Twelve legs of dissected cadavers provided for teaching purposes in the anatomy laboratory were used to display the common peroneal nerve and its branches. Each branch was measured using calipers and analysed to investigate the possibility of neurotisation of the deep peroneal nerve by the superficial peroneal nerve and its branches. It was found that of the measured branches, transposition was possible between those to peroneus longus and tibialis anterior on the basis of their diameter and length. In recent decades, advances in microsurgical reconstruction and understanding of the microanatomy have played major roles in improving the results of surgical treatment of nerve injuries. There is a need for further experimental studies on the feasibility of this surgical approach.  (+info)

Telomerase activity in ductal carcinoma in situ and invasive breast cancer. (4/777)

The increasing number of breast carcinoma in situ detected by screening procedures makes it imperative to develop improved markers to stratify the risk of invasive cancer. Telomerase is detectable in invasive cancer, but not in normal tissues. We have microdissected frozen tissue blocks containing both DCIS and invasive cancer to assay the telomerase activity of these two lesions. The 46 available cases of concurrent DCIS and invasive breast cancer resulted in 43 DCIS samples and 38 invasive cancer samples adequate for analysis. Seventy per cent of the DCIS and all invasive cancer samples tested had detectable telomerase activity. In addition, we analysed telomerase activity in ten cases of DCIS that were not associated with invasive cancer, and detected telomerase activity in seven (70%). Mixing experiments showed no evidence of telomerase inhibitors in telomerase negative samples. Furthermore, periductal inflammatory infiltrates were shown to be a potential confounding source of telomerase activity. Since DCIS lesions appear to be heterogeneous with respect to telomerase activity, and telomerase activation appears to precede the development of invasive cancer, telomerase activity may be a useful adjunct in stratifying the risk of developing invasive breast cancer in patients with DCIS.  (+info)

Quantification of nitric oxide synthase activity in microdissected segments of the rat kidney. (5/777)

This study was designed to quantify nitric oxide synthase (NOS) activity in microdissected glomeruli (Glm), pars convoluta, pars recta, cortical collecting duct, cortical thick ascending limb, outer medullary collecting duct, medullary thick ascending limb and thin limb, inner medullary collecting duct (IMCD) and thin limb, and vasa recta (VR). Total protein from microdissected segments was incubated with L-[3H]arginine and appropriate cofactors, and the L-arginine and converted L-citrulline were separated by reverse-phase HPLC and radiochemically quantitated. NOS activity was found to be greatest in IMCD (11.5 +/- 1.0 fmol citrulline. mm-1. h-1) and moderate in Glm (1.9 +/- 0.3 fmol. glomerulus-1. h-1) and VR (3.2 +/- 0.8 fmol. mm-1. h-1). All other renal structures studied exhibited significantly less NOS activity. The mRNA for NOS isoforms in the NOS activity-positive segments was then identified by RT-PCR. The IMCD contained mRNA for neuronal (nNOS), endothelial (eNOS), and inducible NOS (iNOS), but Glm and VR only expressed the mRNA for nNOS and eNOS. These experiments demonstrate that the greatest enzymatic activity for NO production in the kidney is in the IMCD, three- to sixfold less activity is present in the Glm and VR, and minimal NOS activity is found in other segments studied.  (+info)

Composite low grade B-cell lymphomas with two immunophenotypically distinct cell populations are true biclonal lymphomas. A molecular analysis using laser capture microdissection. (6/777)

Low grade B-cell lymphomas comprise several well defined, clinically and immunophenotypically distinct disease entities. Composite lymphomas showing phenotypic characteristics of more than one of these tumor subtypes in the same site are rare, and both common and separate clonal origins of the two tumor parts have been reported for cases studied by molecular methods. We describe the detailed immunohistochemical and molecular findings in three cases with features of composite low grade B-cell non-Hodgkin's lymphoma (B-NHL). All three neoplasms contained morphologically distinct but interwoven compartments of different cell types, which exhibited discordant expression of several markers, including CD5, CD10, CD43, and cyclin D1. According to their morphology and phenotypes, they were classified as mantle cell lymphoma and follicular lymphoma (Case 1), follicular lymphoma and small lymphocytic lymphoma (Case 2), and mantle cell lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma (Case 3). PCR analysis of DNA obtained from whole tissue sections failed to reveal evidence for biclonality in any of the cases. We therefore isolated cell populations with different antigen expression patterns by laser capture microdissection and analyzed them by polymerase chain reaction amplification and sequencing of clonal immunoglobulin heavy chain gene rearrangements and oncogene rearrangements. Sequence analysis revealed unrelated clonal rearrangements in each of the two tumor parts in all three cases, suggesting distinct clonal origins. In addition, Case 1 showed a bcl-2 rearrangement present only in the follicular lymphoma part. Our findings suggest that low grade B-NHL with two distinct morphological and immunophenotypic patterns in the same anatomical site are frequently biclonal. This is in keeping with current classification schemes, which recognize subtypes of low grade B-NHL as separate disease entities. Furthermore, our analysis demonstrates the power of laser capture microdissection in revealing molecular microheterogeneity in complex neoplasms.  (+info)

Testicular sperm extraction: microdissection improves sperm yield with minimal tissue excision. (7/777)

Testicular sperm extraction (TESE) is often an effective method for sperm retrieval from men with non-obstructive azoospermia. However, TESE has been a blind procedure that does not identify the focal sperm-producing areas of the testicle until after tissue has been excised from the patient. Experience with a new technique of microdissection of testicular tubules is presented here that identifies sperm-containing regions before their removal. Identification of spermatogenically active regions of the testicle is possible by direct examination of the individual seminiferous tubules. The underlying concept for this technique is simple: seminiferous tubules containing many developing germ cells, rather than Sertoli cells alone, are likely to be larger and more opaque than tubules without sperm production. In a sequential series of TESE cases for men with non-obstructive azoospermia, the ability to find spermatozoa increased from 45% (10/22) to 63% (17/27) after introduction of the microdissection technique. Microdissected samples yielded an average of 160,000 spermatozoa per sample in only 9.4 mg of tissue, whereas only 64,000 spermatozoa were found in standard biopsy samples that averaged 720 mg in weight (P < 0.05 for all comparisons). For men where microdissection was attempted, successful identification of enlarged tubules was possible in 56% (15/27) of cases. However, spermatozoa were retrieved with microdissection TESE for six men in whom sperm retrieval was unsuccessful with standard TESE approaches (35% of all men with spermatozoa retrieved). These findings suggest that microdissection TESE can improve sperm retrieval for men with non-obstructive azoospermia over that achieved with previously described biopsy techniques.  (+info)

Endoscopic harvesting of the greater saphenous vein for aortocoronary bypass grafting. (8/777)

We conducted an observational study to evaluate the effectiveness of an endoscopic technique for harvesting the greater saphenous vein for aortocoronary bypass grafting. We hypothesized that the endoscopic technique would minimize the risk of postoperative wound complications. From May 1997 to July 1998, we used an endoscopic technique to harvest the greater saphenous vein in 50 patients who underwent aortocoronary artery bypass grafting. Twenty-five of the patients had an increased risk for wound complications due to preexisting diabetes, obesity, peripheral vascular disease, or lymphedema. The average duration of the procedure was 39 minutes (range, 11 to 70 minutes). The average length of the harvested vein was 58 cm (range, 25 to 85 cm). We made an average of 2.5 incisions per patient (range, 1 to 5 incisions), and the average incision length was 7 cm (range, 3 to 10 cm). Two patients (4%) required conversion to an open technique using 5 small incisions. Postoperative complications included 1 wound infection (2%) and 1 small hematoma (2%). Two patients (4%) had minor erythema at the incision site, and 5 patients (10%) had postoperative lymphedema. The most common problem, ecchymosis, was seen in 6 patients (12%). None required repeat hospitalization or reoperation for wound complications. In our study, the endoscopic approach yielded superior cosmetic results, and reduced wound complications and discomfort, compared with traditional methods of vein harvesting. After gaining expertise with this minimally invasive method of vein harvesting, a surgeon can safely remove the saphenous vein in 20 to 30 minutes.  (+info)