Percutaneous microwave ablation of T1a renal cell carcinomas: A 10-year single-center retrospective review

INTRODUCTION

Partial nephrectomy is currently the preferred treatment option for T1a renal cell carcinomas (RCC), with nephron-sparing techniques, including microwave ablation, becoming more common in select patients. Primary aims are to document outcomes of microwave ablation for T1a RCCs in an Australian tertiary centre to add to the evidence for its safety and efficacy.

METHODS

The prospectively maintained Sir Charles Gairdner Hospital Interventional Radiology database was retrospectively searched for all Renal Microwave ablations completed between June 2012 and February 2022. This database and a combination of hospital programmes including Agfa Impax PACS, Bossnet digital medical record and iSoft Clinical Manager were used to extract the relevant data which was anonymized and entered into an Excel spreadsheet for analysis.

RESULTS

Forty-eight patients underwent microwave ablation for 50 tumours. Of these, there were two local and two distant recurrences. A fifth patient had metastases on presentation. Higher local recurrence rates were associated with larger tumour size (P = 0.043). Tumour proximity to the collecting system <4 mm was associated with higher rates of complications (P = 0.020). RENAL scores did not show statistically significant correlation with complications (P = 0.092) or local or distant recurrence. Notably, the study follow-up time was longer than many comparative studies (mean = 2796, ~7.66 years censoring for death and mean = 832 days, ~2.28 years not censoring for death).

CONCLUSION

Consistent with the literature, this study further demonstrates that microwave ablation is a safe and efficacious option for treatment of T1a RCC.

Mechanism of large optical nonlinearity in gold nanoparticle films

The Z-scan technique, using femtosecond (fs) laser pulses at 1480 nm laser pulses, was used to measure the nonlinear optical properties of gold (Au) nanoparticle (NP) films made by both nanosecond (ns) and fs pulsed laser deposition (PLD) in vacuum. At irradiance levels of 1×10¹²  Wm^-2, the ns-PLD films displayed induced absorption with β=4×10^-5  mW^-1, and a negative lensing effect with n₂=-4.7×10^-11  m² W^-1 with somewhat smaller values for the fs-PLD films. These values of n₂ imply an unphysically large change in the real part of the refractive index, demonstrating the need to take account of nonlinear changes of the Fresnel coefficients and multiple beam interference in Z-scan measurements on nanoscale films. Following this approach, the Z-scan observations were analyzed to determine the effective complex refractive index of the NP film at high irradiance. It appears that at high irradiance the NP film behaves as a metal, while at low irradiance it behaves as a low-loss dielectric. Thus, it is conjectured that, for high irradiance near the waist of the Z-scan laser beam, laser driven electron tunneling between NPs gives rise to metal-like optical behavior.

Light scattering and random lasing in aqueous suspensions of hexagonal boron nitride nanoflakes

Liquid phase exfoliation allows large scale production of 2D materials in solution. The particles are highly anisotropic and strongly scatter light. While spherical particles can be accurately and precisely described by a single parameter-the radius, 2D nanoflakes, however, cannot be so easily described. We investigate light scattering in aqueous solutions of 2D hexagonal boron nitride nanoflakes in the single and multiple scattering regimes. In the single scattering regime, the anisotropic 2D materials show a much stronger depolarization of light when compared to spherical particles of similar size. In the multiple scattering regime, the scattering as a function of optical path for hexagonal boron nitride nanoflakes of a given lateral length was found to be qualitatively equivalent to scattering from spheres with the same diameter. We also report the presence of random lasing in high concentration suspensions of aqueous h-BN mixed with Rhodamine B dye. The h-BN works as a scattering agent and Rhodamine B as a gain medium for the process. We observed random lasing at 587 nm with a threshold energy of 0.8 mJ.

Athermal operation of multi-section slotted tunable lasers

Two distinct athermal bias current procedures based on thermal tuning are demonstrated for a low-cost, monotlithic, three section slotted single mode laser, achieving mode-hop free wavelength stability of ± 0.04 nm / 5 GHz over a temperature range of 8-47 °C. This is the first time that athermal performance has been demonstrated for a three-section slotted laser with simple fabrication, and is well within the 50 GHz grid spacing specified for DWDM systems. This performance is similar to experiments on more complex DS-DBR lasers, indicating that strong athermal performance can be achieved using our lower-cost three section devices. An analytical model and thermoreflectance measurements provide further insight into the operation of multi-section lasers and lay the foundation for an accurate predictive tool for optimising such devices for athermal operation.

Metabolic impact of an NADH-producing glucose-6-phosphate dehydrogenase in Escherichia coli

In Escherichia coli, the oxidative branch of the pentose phosphate pathway (oxPPP) is one of the major sources of NADPH when glucose is the sole carbon nutrient. However, unbalanced NADPH production causes growth impairment as observed in a strain lacking phosphoglucoisomerase (Δpgi). In this work, we studied the metabolic response of this bacterium to the replacement of its glucose-6-phosphate dehydrogenase (G6PDH) by an NADH-producing variant. The homologous enzyme from Leuconostoc mesenteroides was studied by molecular dynamics and site-directed mutagenesis to obtain the NAD-preferring LmG6PDH(R46E,Q47E). Through homologous recombination, the zwf loci (encoding G6PDH) in the chromosomes of WT and Δpgi E. coli strains were replaced by DNA encoding LmG6PDH(R46E,Q47E). Contrary to some predictions performed with flux balance analysis, the replacements caused a substantial effect on the growth rates, increasing 59 % in the Δpgi strain, while falling 44 % in the WT. Quantitative PCR (qPCR) analysis of the zwf locus showed that the expression level of the mutant enzyme was similar to the native enzyme and the expression of genes encoding key enzymes of the central pathways also showed moderate changes among the studied strains. The phenotypic and qPCR data were integrated into in silico modelling, showing an operative G6PDH flux contributing to the NADH pool. Our results indicated that, in vivo, the generation of NADH by G6PDH is beneficial or disadvantageous for growth depending on the operation of the upper Embden-Meyerhof pathway. Interestingly, a genomic database search suggested that in bacteria lacking phosphofructokinase, the G6PDHs tend to have similar preferences for NAD and NADP. The importance of the generation of NADPH in a pathway such as the oxPPP is discussed.

Conical diffraction intensity profiles generated using a top-hat input beam

The phenomenon of internal conical diffraction has been studied extensively for the case of laser beams with Gaussian intensity profiles incident along an optic axis of a biaxial material. This work presents experimental images for a top-hat input beam and offers a theoretical model which successfully describes the conically diffracted intensity profile, which is observed to differ qualitatively from the Gaussian case. The far-field evolution of the beam is predicted to be particularly interesting with a very intricate structure, and this is confirmed experimentally.

White light conical diffraction

Conical diffraction occurs when light is incident along the optic axis of a biaxial crystal. The light spreads out into a hollow cone inside the crystal, emerging as a hollow cylinder. The intensity distribution beyond the crystal is described using an adapted paraxial wave dispersion model. We show, experimentally and theoretically, how this results in a transition from conical diffraction for wavelengths at which the crystal is aligned to double refraction for misaligned wavelengths when using a white light source. The radius of the ring and location of the focal image plane (FIP) are also observed to have a wavelength dependency. The evolution of the conically diffracted beam beyond the FIP into the far field is studied and successfully described using a theoretical model.

Low divergence photonic nanojets from Si3N4 microdisks

High intensity sub-wavelength spots and low divergence nanojets are observed in a system of Si3N4 microdisks illuminated from the side with laser light of wavelengths 488 nm, 532 nm and 633 nm. The disks are of height 400 nm with diameters ranging from 1μm to 10μm. Light scattered from the disk and substrate is observed by imaging from above. In free space light is focused inside the disks and a sub wavelength spot is observed, whereas in water the refractive index contrast is such that photonic nanojets are formed. The angular distribution of the intensity compares well to the analytical solution for the case of an infinite cylinder. Two distinct cases of scattering pattern are observed with even and odd numbers of lobes. Finally when the disks are illuminated with a focused Gaussian beam perpendicular to the substrate an extremely low divergence beam is observed. This beam has a divergence angle over 10 times smaller than a focused Gaussian in free space with the same waist.

Link Family Support - an evaluation of an in-home support service

A significant body of research has shown that parents who have a child or a dependent adult with a disability experience significant and persistent levels of stress. One of the recognized strategies for coping includes the provision of in-home practical support. Enable Ireland provides a range of services for children and adults with a physical disability. The present study explored home support services with a sample of 16 families of service users of Enable Ireland Cork. Practical support was deemed to be whatever support or intervention requested by the parent of the child/dependent adult which afforded the service user the opportunity to engage in social/recreational opportunities and that gave the parent free time. Sixteen members of the chosen families were interviewed (15 mothers and one father) using a semi-structured interview schedule and a standardized stress measure before and after the introduction of Link Family Support (LFS). LFS was put in place for a period of 12 months, tailored to the families and service users' individual needs. Although levels of stress continued to be high and scores on the Parenting Stress Index (PSI) did not show a statistically significant reduction after the programme, reported stress levels had improved. Parents reported LFS to be very helpful in reducing perceived stress and improving family's quality of life through providing free time and access to leisure and recreation facilities. This study provided limited but clear evidence of the need for regular, flexible, in-home support for families with children and dependent adults with a disability. LFS provided a personal, regular and effective means of meeting this need as the findings of this study demonstrated.

Major histocompatibility complex susceptibility genes and immune thrombocytopenic purpura in Caucasian adults

Immune thrombocytopenic purpura (ITP) is a heterogeneous disorder with wide variability in response rates to treatments including corticosteroids, splenectomy and intravenous immune globulins. The nature of the underlying predisposing causes for this autoimmune disorder are not known. We have HLA typed 71 adult Caucasian patients with chronic primary ITP, and compared the data with 750 control samples. In this association study, we were not able to identify a significant immunogenetic susceptibility factor for ITP with HLA class I and class II alleles. However, it appeared that there might be an association between HLA-A2 and ITP, particularly in female patients, who are the predominantly affected group; and HLA-A2 was also present at increased frequency in patients with chronic ITP progressing to splenectomy. These findings are reviewed in the context of other similar reported HLA studies in ITP. Further studies based on larger groups of patients will be necessary to identify genetic susceptibility factors for this disease.

Delayed micromolar elevation in intracellular calcium precedes induction of apoptosis in thapsigargin-treated breast cancer cells

Thapsigargin (TG), a highly specific inhibitor of the sarcoplasmic reticulum and endoplasmic reticulum Ca2+-ATPase pump, can induce apoptosis in a variety of epithelial and lymphoid cell types. In prostate cancer cell lines, TG induces an initial 5- to 10-fold elevation of intracellular calcium ([Ca2+]i) within a few minutes of exposure. With prolonged exposure times (i.e., 12-36 h) a second elevation of [Ca2+]i to >10 microM is observed. In this study, the human breast carcinoma cell lines MCF-7 and MDA MB 468 cells were used to determine the temporal relationship between TG-induced elevation of [Ca2+]i and activation of programmed cell death. Using a microinjection method that allows for long-term analysis of [Ca2+]i changes, we found that after TG exposure, calcium measurements in these cells demonstrated an initial rise (>4-fold) in [Ca2+]i that occurred within minutes and returned to baseline within a few hours. With prolonged TG exposure, the cells underwent a second elevation (>5 microM) of [Ca2+]i occurring stochastically between 12 and 36 h after the initial exposure to TG. Both of the cell lines were growth-inhibited by 100 nM TG after only 1 h of exposure, but clonogenic ability in the MCF-7 cells was significantly reduced only after 48 h of exposure. The induction of apoptosis by TG was demonstrated by morphological changes typical for programmed cell death and DNA fragmentation (both high molecular weight and oligonucleosomal-sized fragments were detected) after 48 h of treatment. TG induction of apoptosis in these breast cancer cells occurred subsequent to the secondary rise in [Ca2+]i, which confirmed that this secondary rise in [Ca2+]i is not prostate cancer-specific. The secondary rise in [Ca2+]i to micromolar levels may directly activate the endonucleases responsible for DNA fragmentation that occurs as part of the apoptotic process. These studies indicate that TG is an active agent in vitro against breast cancer cells. Inactive prodrug analogues of TG are currently being developed that can be activated by tissue-specific proteases, and further pursuit of this strategy as a potential treatment for breast cancer is warranted.

High-resolution sonography of the abnormal cranial suture

OBJECTIVE

The purpose of this investigation is to elucidate the sonographic features of abnormal major cranial sutures.

MATERIALS AND METHODS

Eight excised synostosed suture specimens were evaluated. The high-resolution sonographic appearance was correlated with the histological section, plain radiographs, CT and MRI. Diastatic and molded sutures were also evaluated with sonography and compared with the normal cranial suture appearance.

RESULTS

Synostosed sutures demonstrated one or more of the following features: (a) loss of echo-poor fibrous gap between bony plates (five sagittal and coronal synostoses); (b) irregular thickened inner sutural margin (three lambdoid synostoses); (c) loss of bevelled edge (one lambdoid synostosis); (d) asymmetric anterior fontanelle (one coronal synostosis). Cranial molding results in an overlap of echogenic bony plates. Sutural width (the distance between bony plates) is increased in cases of elevated intracranial pressure.

CONCLUSION

Sonography is an inexpensive, radiation-free modality which can confirm synostosis versus molding versus an underlying intracranial lesion as a cause of plagiocephaly. The high-resolution sonographic images also provide a relatively easy means to assess sutural width and may provide information in regard to increased intracranial pressure.

Sclerosing cholangitis, race and sex

BACKGROUND

Primary sclerosing cholangitis develops in 3-10% of patients with ulcerative colitis, and may be associated with an increased cancer risk. Ulcerative colitis is probably less common in people of African origin than in populations of European descent.

AIMS AND METHODS

To review the records of all patients under regular follow up for ulcerative colitis at St Bartholomew's Hospital (London, UK), a tertiary referral centre, prompted by discovering a cluster of cases with common features.

RESULTS AND CONCLUSIONS

Among 166 patients with ulcerative colitis under regular follow up, only four (all women) are of African or Caribbean genetic origin, and three of these have developed sclerosing cholangitis within three years of presentation with colitis, compared with four of 162 patients of European or Asian descent (odds ratio 119, 95% confidence interval 8-3837; p = 0.0002). This cluster, which is not explained by common HLA DR or DQ type, suggests that Africans and Afro-Caribbeans, especially women, may be at increased risk of sclerosing cholangitis. This may reflect genetic influences on the development of enteric and hepatobiliary inflammatory disease.

Sonography of normal cranial sutures

OBJECTIVE

The purpose of this study was to describe the normal sonographic appearance and measurement of normal major cranial sutures in neonates and infants.

SUBJECTS AND METHODS

High-resolution sonograms of sagittal, coronal, and lambdoid sutures were obtained for two autopsy specimens and correlated with histologic sections obtained at identical locations. Also, 50 neonates and infants (0-5 months old [corrected age]) who had normally shaped craniums underwent sonography of the brain that produced normal findings. These neonates and infants also underwent sutural sonograms. The width and thickness of each of the major cranial sutures (sagittal, coronal, and lambdoid) were measured, with mean values established. Measurements were analyzed with paired t tests for interobserver variability. Linear regression was used for correlation of measurements with age.

RESULTS

With a scan plane perpendicular to the suture line, sonograms revealed sutures as hypoechoic gaps between two hyperechoic bony plates. On sonograms, sagittal sutures had an end-to-end appearance instead of the beveled junction seen throughout most of the coronal and lambdoid sutures. In the 50 patients, sonograms revealed the mean width to be 0.89 +/- 0.35 mm (mean +/- SD) for coronal sutures. 0.93 +/- 0.28 mm for sagittal sutures, and 0.96 +/- 0.39 mm for lambdoid sutures. On sonograms, mean thickness was 1.97 +/- 0.54 mm for coronal sutures, 1.88 +/- 0.56 mm for sagittal sutures, and 2.49 +/- 0.86 mm for lambdoid sutures. We found no interobserver variability (p < or = .05). With linear regression analysis, we found no correlation between suture width or thickness and patient age (r = .01).

CONCLUSION

In our study, high-resolution sonography proved to be a reliable and inexpensive technique capable of defining cranial sutures. Preliminary normative data obtained for cranial suture width and thickness showed no correlation with age in our population group. The normative data obtained will allow recognition of abnormal sutures, particularly synostotic or diastatic sutures.

Evaluation of the flow cytometric crossmatch. Preliminary results of a multicenter study

The flow cytometric crossmatch is a technique that is increasingly being used by clinical transplant laboratories. In this multicenter study by the British Society for Histocompatibility and Immunogenetics Flow Cytometry Group, a series of crossmatches were carried out to determine whether different centers obtained same results when performing the same crossmatch. There was greater than 80% agreement among participating laboratories on the results of 35/54 tests. There was no clear agreement in the remaining 20 cases. Quantitative analysis, estimating the number of cell-bound fluorescein molecules, demonstrated that differences in the criteria used by each center to define a positive crossmatch were responsible for some discordant results. When applied, definition of positivity based on the molecules of fluorescein increased concordance from 57.5% to 81.4%.l. These results suggest that a criterion for the interpretation of results based on quantitative analysis of bound antibody may be more reliable than methods in current routine use.

Recurrent erythema multiforme: tissue typing in a large series of patients

Previous reports have shown an increased frequency of certain HLA antigens in association with erythema multiforme, including HLA-B15(B62), HLA-B35, HLA-A33, HLA-DR53 and, more recently, HLA-DQB1*0301. A strong association with HLA-DQ3 has been documented in patients with recurrent erythema multiforme. We have performed HLA typing in 39 patients with recurrent erythema multiforme, of whom 33 were associated with herpes simplex virus infection. The results were compared with 309 controls. In the recurrent erythema multiforme patients there was a statistically significant increase in HLA-B62 and HLA-B35. An increase in HLA-DR53 was also found, although this did not reach statistical significance. There was no increase in HLA-A33. The presence of HLA-DQ3 in the study population approached that in the controls. Finally, the study population demonstrated a trend towards a reduction in the HLA antigens A1, B8 and DR3. The study confirms the previously reported associations with HLA-B62 (B15), HLA-B35 and HLA-DR53. We have been unable to confirm an association of HLA-A33 or HLA-DQ3 with erythema multiforme. The HLA antigens A1, B8, and DR3 are associated with autoimmune disease, reflecting an increased host response to tissue self antigens. Their absence in patients with recurrent erythema multiforme (REM) may be an indicator of a poor host response to an antigen, which in the case of REM is the herpes simplex virus.

A comparative serological and molecular study of linear IgA disease and dermatitis herpetiformis

The class I and class II HLA serologically defined antigens and DQ alpha and DX alpha restriction fragment length polymorphism (RFLP) in 23 patients with linear IgA disease (LAD) were determined and their frequencies compared with those in a group of patients with dermatitis herpetiformis (DH) and healthy controls. In LAD there was a significant increase in HLA-B8 and DR3 and a larger increase in the DQw1-DR2/DRw6 related DQ alpha 6.2 kb and 6.8 kb RFLP. In DH there was a significantly increased frequency of HLA-A1, B8, DR3, and DQw2 with a concomitant increase in the DR3-DQw2 related DQ alpha 4.6 kb RFLP. The difference in DR3 frequencies and the increased frequency of DQw1 rather than DQw2 in LAD indicates that different susceptibility genes operate in the two diseases.

HLA and rheumatoid arthritis: an analysis of multicase families

In a study of multicase RA families, significantly raised frequencies of the HLA antigens DR4, DR1, Bw62, Cw3, A2, A31 and significantly lower frequencies of DR2, DR3, and B8 were found in probands compared to normal controls. When haplotype frequencies were compared between probands and controls, two haplotypes A2-B44-DR4 and A2-Bw62-DR4 were at higher frequency in probands. These differences no longer reached significance when only DR4-containing haplotypes were compared between probands and controls. A significantly lower haplotype frequency of A1-B8-DR3 was observed in probands compared to controls. This difference did not remain significant when only non-DR4 haplotypes were compared. Using an affected sibling pair ratio method, significant linkage between HLA and RA was found (P less than 0.01). Significant linkage was also observed between HLA and seropositivity. Analysis of Hardy-Weinberg equilibrium for the DR locus did not support the suggestion that DR4-associated RA susceptibility was inherited as a dominant trait. In addition it did not support the notion of an additive effect of DR4 and DR1 in RA susceptibility as these antigens were not found together more frequently than predicted by their individual gene frequencies.

HLA frequency and haplotype analysis in a family study of adult onset rheumatoid arthritis

Twenty-five families with probands who have rheumatoid arthritis (RA) were studied for clinical evidence of disease and for HLA status. This confirmed an association between RA and DR4 in 19/25 probands (76 per cent, p = 0.008). These 19 probands carried 24 haplotypes which contained DR4. There was no significant increase of DR4 haplotypes bearing B15(Bw62) or B44 when compared with published control haplotype data. The rare complement allele C4 B3 was detected as part of the extended haplotype A2 Cw3 B15(Bw62) DR4 C4 A*3B*3 in three probands with severe RA. Further studies to examine disease severity and autoantibody expression are in progress.

Different HLA associated gene combinations contribute to susceptibility for coeliac disease and dermatitis herpetiformis

Forty two white patients of British or Irish descent with coeliac disease and 28 with dermatitis herpetiformis were typed for class I HLA-A, B, and C, and class II DR and DQ antigens. In coeliac disease there was a significant increase in the frequencies of A1, B8, DR3, DR7, and DQw2 compared with controls but no increase of DR2. In dermatitis herpetiformis there were similarly increased frequencies of A1, B8, DR3, and DQw2. In contrast with coeliac disease, however, the frequency of DR7 (18%) was no different from the control group but there was an increased frequency of DR2.

HLA class I and class II antigen associations in acute leukaemias

HLA-A,B,C and DR antigen frequencies were determined in a group of 188 patients suffering from acute myeloid (AML) and acute lymphoid leukaemia (ALL). These antigen frequencies were compared with those obtained on a panel of normal individuals (n = 109) of the same ethnic origin. The significance of the differences in the antigen distribution and the strength of the associations between particular HLA antigens and the disease were then calculated. The results obtained show a decreased frequency of HLA-Aw19 in the overall group of patients and the group of patients with ALL. In addition, the antigen frequency of the HLA-B18 and DR5(DRw11) antigens was also decreased in the overall group of patients and in those patients with AML but not in the patients with ALL. The results suggest that the antigen Aw19 may confer some degree of resistance to the development of ALL and that the HLA-B18 and/or DR5 antigens may be resistance factors for the development of AML.

Experimental subglottic stenosis: histopathologic and bronchoscopic comparison of electrosurgical, cryosurgical, and laser resection

Controversy continues over the optimal method of resecting subglottic stenosis. Electrosurgery, cryosurgery and laser resection have all had some clinical success. We sought to compare these treatment methods in experimentally-created subglottic stenosis. Subglottic strictures were created transbronchoscopically in newborn lambs by electrocoagulating a rim of mucosa. Four weeks later, all had 20 to 90% occlusion documented bronchoscopically. Control animals were found to have dense submucosal fibrosis in the cricoid area. Remaining experimental animals were treated with: (1) electrosurgical resection; (2) cryosurgical treatment; (3) Neodymium-yag (Nd:Yag) laser at 20 watts; (4) Nd:Yag laser with 40 watts; or (5) carbon dioxide laser at 10 watts. Animals from each group were sacrificed at 5 and 30 days postresection and the tracheas were examined grossly and microscopically. Animals sacrificed at 30 days postresection were bronchoscoped at weekly intervals. Cryosurgical and electrosurgical resection resulted in 1-3 mm of thermal damage adjacent to the margin of resection at 5 days post-treatment. Mucosal ingrowth and healing were rapid and there was no development of stenosis or damage to underlying structures. Use of the Nd:Yag laser resulted in 10-20 mm of surrounding damage in animals sacrificed at 5 days. At 30 days posttreatment, there was mucosal healing but extreme underlying damage and redevelopment of stenosis at the level of treatment. The carbon dioxide laser-treated animals showed thermal damage present up to 2 mm in depth from resected areas at 5 days post-treatment. Mucosal regeneration proceeded rapidly. This study indicates that electrosurgical and cryosurgical resection for experimental subglottic stenosis create minimal thermal damage and are associated with comparably acceptable rates of mucosal ingrowth and healing. The carbon dioxide laser created comparable to slightly decreased thermal damage but suffers at present from lack of optimal visualization of the subglottic lesion.

Anatomy and techniques in segmental splenectomy

Accumulating clinical experience indicates the desirability of retention of splenic tissue and function. Results of angiographic studies in human and canine spleens demonstrate that intrasplenic vessels are lobar, segmental and, generally, without intersegmental communication. In the dog, bleeding from peripheral region vessels--penicilli, venules and sinuses--is well controlled by either microfibrillar collagen or the neodymium yttrium aluminum garnet laser. However, larger segmental vessels in the intermediate or hilar regions cannot be controlled by microfibrillar collagen or the neodymium yttrium aluminum garnet laser and require ligation. Identification of these vessels is greatly facilitated by laser or microfibrillar collagen coagulation of the surrounding splenic tissue. Results of histologic studies at ten, 20 and 30 day healing intervals disclosed no delayed sloughs, hemorrhage or cyst formation. With knowledge of segmental vascular anatomy and the techniques of microfibrillar collagen, neodymium yttrium aluminum garnet laser incision and coagulation plus aspiration and vessel ligation, segmental or subtotal splenic resection can be readily accomplished in dogs with minimal blood loss.

Adult hemolytic uremic syndrome with renal arteriolar deposition of IgM andC3

Two cases of idiopathic adult hemolytic uremic syndrome in which deposits of IgM and C3 were identified in renal arterioles showing fibrinoid necrosis are reported. Fibrin was also identified in the lumina of the involved vessels, but there was no laboratory evidence of disseminated intravascular coagulation. In both cases, serum C3 was decreased and C4 was normal, suggesting involvement of the alternate pathway of complement activation. These two cases suggest that in some instances the adult hemolytic uremic syndrome may be immunologically mediated, and that renal vascular thrombosis is a secondary phenomenon.

Transampullary septectomy for post-cholecystectomy pain

Twenty-eight patients with chronic, incapacitating upper abdominal pain after cholecystectomy had excision of the common wall between the terminal bile duct and duct of Wirsung (ampullary septum). Twenty-two also had a sphincteroplasty: six had had this procedure previously. Pancreatic function studies, scintiscans, ultrasound and pancreatograms were non-diagnositic. Hyperamylasemia was an uncommon finding. Eight patients were found to have evidence of mild pancreatitis at exploration. There was gross scarring of the ampullary septum in 22 cases. Histologic examination revealed inflammation in 12 septa; the degree of fibrosis could not be assessed since 14 control septa from autopsy material free from biliary tract disease revealed a comparable degree of collagen and smooth muscle. There were no deaths, and minimal morbidity. In follow-up from seven to 59 months (mean = 26), 16 patients are relatively free of pain, five have occasional episodes which require non-narcotic analgesics, and seven have gained no relief from the operative procedure. A randomized controlled trial is recommended.