Methyl-methacrylate as an embedding medium in histopathology

Methyl-methacrylate embedding makes it possible to obtain semi-thin sections rich in detail and without tissue shrinkage. The procedure requires considerable time and labour, and great care must be taken to prevent heat damage to the tissue during the exothermic polymerization process. The original method given by Burkhardt (1966) and later modifications are described and discussed, with special attention to the practical problems encountered and their solutions.     

Population haplotype analysis and evolutionary relations of the COL2A1 gene

We have determined the allele frequencies and pairwise linkage disequilibria of restriction fragment length polymorphisms (RFLPs) distributed over the entire COL2A1 gene (spanning 23.6 kb) in a population of unrelated Dutch Caucasians. Pairwise linkage disequilibrium analysis of RFLP sites between exon 5B and 51 indicated a high degree of partly positive (the rare alleles of both loci are associated) and partly negative (the rare allele is associated with the common allele) linkage disequilibrium.
The high degree of linkage disequilibrium enabled the assignment of 13 out of 128 possible haplotypes with 7 RFLPs. An evolutionary tree of these haplotypes was derived using a minimum spanning tree approach, indicating at least two ancestral haplotypes. Our data indicate that disease related population studies involving the COL2A1 gene should include a minimum of 4 RFLPs (D9, A9, H33, P51) to obtain 98% of possible haplotypes occurring.     

Recurrent acute splenic sequestration crisis due to interacting genetic defects: hemoglobin SC disease and hereditary spherocytosis

A 14-year-old boy with hemoglobin SC disease and alpha-thalassemia-2 experienced five episodes of acute splenic sequestration crisis (ASSC), while two of his siblings with identical globin genotypes (SC and - alpha/alpha alpha) had no such experience. To determine if an additional red blood cell (RBC) defect was responsible for the unusual occurrence of frequent ASSCs, we performed detailed rheologic characterization and membrane protein analysis on RBCs from the proband and other members of his family. Reduced surface area, increased mechanical instability, and decreased spectrin content of the membrane, distinguishing features of RBCs in hereditary spherocytosis, were observed in cells from the proband and his mother, but not in cells from other family members. These findings are consistent with the dominant inheritance of spherocytosis by the proband. We suggest that the combined effects of SC disease and spherocytosis in the proband resulted in decreased RBC deformability and led to increased splenic trapping, intrasplenic sickling, and consequently, recurrent sequestration crisis. Marked clinical and hematologic improvement occurred from splenectomy. Thus, inheritance of interacting genetic defects, sickling hemoglobinopathy, and hereditary spherocytosis appear to be responsible for the unusual clinical manifestation of recurrent ASSC in this patient.     

不同手术方法治疗不稳定Hangman骨折的疗效观察

目的探讨不同手术方法治疗不稳定Hangman骨折的临床疗效。方法 14例不稳定Hangman骨折患者根据Levine-Edwards分型:Ⅱ型7例,ⅡA型5例,Ⅲ型2例。4例行后路C2,3椎弓根螺钉内固定术,7例行前路C2,3间盘摘除减压植骨融合内固定术,3例行前后路联合手术。结果患者均获随访,时间3~24个月。1例患者术后3个月单侧椎弓根处可见模糊骨折线,13例患者均达到骨性愈合。术中及术后未出现椎动脉、脊髓损伤及脑脊液漏等并发症,未发生钢板螺钉断裂内固定失效等现象。结论对于不稳定Hangman骨折无论是采取前路或者后路手术均可使骨折达到骨性愈合,对严重骨折伴脱位Hangman骨折可以采取前后路联合的手术方式。     

Sacral insufficiency fractures: an unsuspected cause of low back pain [clinical conference]

We describe 10 cases of sacral fractures diagnosed within the rheumatology department at Southend Hospital over the last 5 yr. All presented with sudden-onset low back pain. The majority were elderly, frail, with chronic inflammatory disease (six with rheumatoid arthritis, one with polymyalgia rheumatica, one with vasculitis) and had received steroids. Diagnosis was delayed by the inability of plain radiographs to show these fractures and was ultimately demonstrated by technetium scintigraphy/computed tomography scan. We feel that this diagnosis should be considered in elderly patients with rheumatoid arthritis or other risk factors for osteoporosis who present with low back pain and sacral tenderness. Further clues may be parasymphyseal tenderness (suggesting associated pubic ramus fracture), elevated alkaline phosphatase and plain radiograph showing pubic ramus fractures or parasymphyseal sclerosis. Patients with this complication generally have a poor prognosis and two of our patients have died. Seven required in-patient stay (mean 20 days; range 14-41). The mortality, morbidity and costs incurred in management may be comparable to those of femoral neck fractures.      

The renin-angiotensin system and drinking in the euryhaline flounder, Platichthys flesus

Drinking behaviour and its possible regulation by the renin-angiotensin system (RAS) has been examined in the euryhaline flounder. Fluid intake was greater in seawater (SW)-adapted than freshwater (FW)-adapted fish, the latter having significantly lower plasma sodium, chloride, and osmotic concentrations. Oesophageal cannulation in SW-adapted fish resulted in further elevation of drinking rates, which increased proportionally with progressive body water loss as measured by the fall in body weight and rise in plasma tonicity. The influence of the RAS on drinking in SW-adapted fish was examined in animals with an intact gastrointestinal tract. Fluid intake fell markedly following administration of the converting enzyme inhibitor, Captopril. Infusions of angiotensin I (AI) and angiotensin II (AII) induced dose-related increments in the rate of drinking. The increased drinking in response to AI was inhibited, however, by the simultaneous administration of Captopril. The results are consistent with the presence in the flounder of the major elements of the RAS, including AI, AII, and a converting enzyme-like substance. The RAS appears to play an important regulatory role in the adaptative drinking behaviour associated with migration of euryhaline teleosts between FW and SW.     

The Index of Microcirculatory Resistance Postpercutaneous Coronary Intervention Predicts Left Ventricular Recovery in Patients With Thrombolyzed ST‐Segment Elevation Myocardial Infarction

Background

The index of microcirculatory resistance (IMR), an invasive measure of microvascular function, has been shown to correlate with clinical outcomes in patients with ST‐segment elevation myocardial infarction (STEMI). The aim of this study is to evaluate the predictive value of IMR on left ventricular recovery in patients undergoing a pharmacoinvasive strategy for STEMI.

Methods

The index of microcirculatory resistance was assessed following percutaneous coronary intervention (PCI) in 31 patients with STEMI who were initially managed with thrombolysis. Other markers of microvascular function such as coronary flow reserve (CFR), TIMI flow grade, corrected TIMI frame count (cTFC), and ST‐segment resolution were also recorded. All indices were evaluated against measures of left ventricular function and recovery 3 months postindex event.

Results

The IMR correlated with left ventricular function, as assessed by wall motion score and ejection fraction at 3‐month follow‐up (r = 0.652, P = 0.005; r = ?0.452, P = 0.011, respectively). The traditional methods of assessing microvascular function, such as CFR, TIMI flow grade, cTFC, and ST‐segment resolution did not correlate with wall motion score and ejection fraction at 3 months. Post‐PCI IMR was significantly lower in those patients with left ventricular recovery at 3 months (18 U vs 39 U, P < 0.001). The optimal cut‐off value for post‐PCI IMR and left ventricular recovery was 32 U. In patients in whom the IMR was greater than 32 U, the percent change in ejection fraction was significantly lower than in those patients in whom the IMR was less than 32 U (2 ± 11 vs 12 ± 8, P = 0.012).

Conclusions

In patients presenting with STEMI initially managed with thrombolysis and subsequently undergoing PCI, IMR correlates with measures of left ventricular function and has the potential to predict left ventricular recovery at 3 months. (J Interven Cardiol 2016;29:146–154)

     

Quantifying the relationship of HIV infection with clinicopathological spectrum and outcome among patients with colorectal cancer in a South African population

IntroductionLiterature is limited on HIV and colorectal cancer (CRC) in sub-Saharan Africa despite it being the epicentre of the HIV epidemic,PurposeTo compare clinicopathological features and outcome of CRC in HIV-negative and HIV-positive patients.MethodsRetrospective analysis of a prospective CRC database. Demographic details, HIV status, anatomical site, disease stage, treatment and follow-up were documented.ResultsOf 715 patients with CRC, 145 and 570 tested positive and negative respectively for HIV. Median age was 45 (IQR 36–53 and 57 (IQR 45–66) years among HIV-positive and HIV-negative patients respectively (p<0.0001). Tumour differentiation differed between the two groups (p=0.003) but staging was not different (p=0.6). Surgical resection rate was 52% for HIV-positive patients versus 59% for HIV-negative patients (p=0.07). Median follow-up was 9 (IQR 2–20.5) months for HIV-positive patients and 12 (IQR 6–29) months for HIV-negative patients (p=0.154). Recurrence rate was 14.7% among HIV positive patients and 6.8% in HIV negative patients (p=0.089).ConclusionWhen compared with HIV-negative patients, HIV-positive patients with CRC presented at a younger age and tended to have lower surgical resection rates. There was no difference between the two groups with CRC in terms of anatomical sub-site distribution, disease staging and recurrence rates.