Validity of a hinged constant force probe and a similar, immobilised probe in untreated periodontal disease

The validity of a hinged constant force probe (0.25 N) was compared with that of a similar but immobilised instrument, using the same interchangeable tip for both (0.64 mm diameter; 2 mm divisions). 60 sites were measured on teeth which were extracted subsequently, in patients with untreated periodontal disease, and the connective tissue attachment level was used as validity criterion. The clinical measurements of both probes correlated well with each other, but they differed significantly from the post-extraction connective tissue attachment level measurements, indicating a point 1.2 mm coronally to this, on average. A companion investigation of intra-operator probing depth reproducibility with the 2 probes, was undertaken in 14 patients, at 2 visits separated by 1 week in each case. All patients had untreated periodontal disease. A difference between probes was found at the first visit, but not at the second; the immobilised probe showed a difference between visits, reducing mean probing depth slightly at the second; when the immobilised probe was used first, there was a difference between probes. Further analysis of the results indicated that there was greatest agreement between probes when the constant force probe had been used before the immobilised probe at the second visit. The results suggested that these probes indicated a point above the connective tissue attachment level, related to pocket morphology, and that there was a moderate learning effect due to operator use of the constant force probe, which modified use of the immobilised probe.     

Drug-Biomacromolecule Interaction XII: Comparative binding study of sulfaethidole to bovine serum albumin by equilibrium dialysis,fluorescence probe technique,uv difference spectrophotometry and circular dichroism

Binding of sulfaethidole to bovine serum albumin was studied by equilibrium dialysis, fluorescence probe technique, uv difference spectrophotometry and circular dichroism. Equilibrium dialysis method enabled us to estimate the total number of drug binding sites of albumin molecule. For sulfaethidole, albumin had 6 primary and 40 secondary binding sites. The primary and secondary binding constants were 0.9×10⁵ M⁻¹ and 0.2×10⁶ M⁻¹, respectively. 1-Anilino-8-naphthalenesulfonate (ANS) and 2-(4′-hydroxylbenzeneazo)-benzoic acid (HBAB) were used as the fluorescence probe and the uv spectrophotometric probe, respectively. In fluorescence probe technique, results indicated that the number of higher affinity drug binding site of albumin was 1 and the number of lower affinity drug binding sites of albumin was 3, and the primary and secondary drug binding constants for bovine serum albumin were 2.15×10⁵ M⁻¹ and 1.04×10⁵ M⁻¹, respectively. In uv difference spectrophotometry, binding sites were 3 and binding constant was 1.88×10⁵ M⁻¹. The above results suggest that several different methods should be used in ompensation for insufficient information about drug binding to albumin molecule given by only one method.     

Experimental study of spinal cord compression by epidural tumors using electron probe X-ray microanalysis and confocal laser scanning microscopy

Changes in the nerve fibers of the spinal cord were studied in rat experimental epidural tumor models. Light microscopy showed demyelinization in all with rats paraparesis and paraplegia. Cross-sectional views of nerve fibers stained with 3,3dipentyloxacarbo-cyanine iodide, obtained by confocal laser scanning microscopy, showed distorted, shrunken fibers with a low fluorescence intensity. Changes in the electrolyte contents of nerve fibers were studied by electron probe X-ray microanalysis. The K concentration in axons and the myelin sheath was increased in the paraparesis group, but was decreased in the paraplegia group. These findings suggest that, in the paraparesis group, compression of the spinal cord damaged cell membrane channels, which subsequently caused an increase in intracellular K, a decline in the action potential, and low-intensity fluorescence of nerve fibers. On the other hand, in the paraplegia group, destruction of cell membranes caused a decrease in intracellular K until it approached the extracellular level. This reduced both the action potential and the fluorescence intensity. As Ca and Mg concentrations in both axons and the myelin sheath increased in relation to the severity of neurologic damage, it appears that these electrolytes may also play an important role in damage to nerve fibers.     

用荧光探剂DPH研究家蝇线粒体膜脂流动性

本文探讨了用ＤＰＨ作为荧光探剂，研究家蝇飞翔肌线粒体膜脂流动性的方法。实验表明：ＤＰＨ确是用来研究家蝇生物膜流动性的有效探剂。同时，初步观察了不同杀虫剂对ＤＰＨ与线粒体膜结合后荧光强度的影响。其中氯菊酯和倍硫磷、马拉硫磷、敌百虫、氧化乐果，可使ＤＰＨ探剂与线粒体膜结合后的荧光相对强度增加；而氰戊菊酯、氯氰菊酯，溴氰菊酯及辛硫磷、乙酰甲胺磷，则可使荧光强度减弱。     

Probe tine diameter and probing depth

The aim of this study was to assess the effect of difference in tine diameter on probing pocket depth measurement. 2 sets of tines with Williams markings at 1, 2, 3, 5, 7, 8, 9 and 10 mm, and with a "round" tip, diameter 0.5 mm, were compared. One set was described as parallel-sided, the other as tapered. The parallel-sided tine was almost parallel from the 10 mm marking to the tip (tip diameter mean = 0.46 mm, 95% C.I. 0.456-0.464), while the corresponding diameter for the tapered tine varied (tip diameter mean = 0.48 mm, 95% C.I. 0.473-0.489). Calibration markings appeared highly consistent with the expected value to within 0.01 mm. The tines were mounted in Brodontic handles at 0.25 N. Examiner probing repeatability yielded kappa 0.86 for "parallel-sided" and 0.81 for "tapered" tines in vivo. 412 approximal pockets were assessed in 53 patients with routine chronic adult periodontitis, mean age 42.1 years. Each site had a probing depth of greater than or equal to 5 mm, PlI less than or equal to 1, GI less than or equal to 1, PBI less than or equal to 1. Each site was probed 2x with a 15-min interval. At the first 251 sites, the parallel-sided tine was used initially, and the tapered at the remaining 161 sites. Results indicated a highly significant tendency for the parallel-sided tine to yield a deeper reading when a difference occurred. These findings indicate that with adequate training providing high examiner repeatability, one source of error in probing data can be minimised.     

Use of a mouth gag instrument to facilitate bite block insertion and prevent finger and probe bites during transesophageal echocardiography

Transesophageal echocardiography greatly enhances the examination of patients difficult to image transthoracically. While of low patient risk, a potential for harm from human bites to the echocardiography staff and to the transesophageal probe remains, particularly when dealing with uncooperative patients. This risk potential prompted implementation of additional anti-bite protection in our universal precautions policy beyond use of a standard mouth guard. A mouth gag instrument was modified by placing latex rubber tubing over the instrument blades. This instrument was inserted into the mouth and set in an open position giving the operator safe access for probe and mouth bite guard insertion. This technique improved access to the patient's mouth and visualization of probe insertion without the mouth bite guard. The mouth gag instrument provided an insertion of the transesophageal probe in impaired or otherwise uncooperative patients, which was safer for the patient, laboratory staff, and the probe itself.     

Pemphigus Vulgaris Autoantibody Response is Linked to HLA-DQB10503 in Pakistani Patients

ABSTRACT: Pemphigus vulgaris (PV) is an autoimmune disease of the skin and mucous membranes characterized by an autoantibody response against an epidermal cadherin. We performed high resolution HLA class II typing in 19 patients with PV from Rawalpindi, Pakistan and 19 non-Jewish European PV patients from Boston by sequence-specific oligonucleotide probe hybridization. The results were compared with two separate ethnically matched control populations. We found that PV patients from Pakistan had significantly increased frequencies of DRB1*1404 ( p = 0.01), DQA1*0101 ( p = 0.02), and DQB1*0503 ( p = 0.01). Among the patients of non-Jewish European ancestry, DRB1*1401 ( p < 10⁻⁶), DQA1*0101 ( p < 10⁻⁵) and DQB1*0503 ( p < 10⁻⁶), were increased in PV patients. Formal linkage analysis between the major histocompatibility complex and the PV antibody was performed in 67 relatives of the 19 Pakistani patients. The results showed strong evidence for linkage of HLA-DRB1*1404, DQA1*0101, DQB1*0503, with the presence of PV antibody in relatives’ families with a significant logarithm of the odds score of 6.06. Based on the three dimensional structure of class II molecules, we propose that HLA-DQA1*0101 and DQB1*0503, encode a negatively charged P9 peptide binding pocket of the DQ molecule and are significantly associated with susceptibility to PV in non-Jewish populations.     

基因探针监测巨细胞病毒潜伏感染的母儿间传播

本文采用基因探针检测孕妇静脉血及新生儿脐静脉血白细胞中CMVDNA，同时应用ELISA检测其血清中IgG、IgM．结果：10例孕妇CMV-DNA阳性，占8．7％(10／115)，这10例孕妇血IgG均阳性，IgM均阴性；17例新生儿CMV—DNA阳性．占14．3％(17／119)，其中IgM阳性2例，占1．7％(2／119)。本次研究中配对者79例，母儿CMV—DNA均阳性者8例，新生儿CMV—DNA阳性而母亲阴性者4例。上述CMV-DNA阳性者均无临床症状。研究结果提示基因探针可监测CMV的潜伏感染，从而进一步研究CMV感染的母儿传播机制。     

High prevalence of mixed genotype infections in hepatitis B virus infected intravenous drug users

The clinical relevance of hepatitis B virus (HBV) genotypes has been documented; however, the prevalence of mixed HBV genotype infections in at-risk groups remains controversial. The HBV genotypes were determined in 325 HBV-infected intravenous drug users (IVDU) who were at a greater risk of multiple exposures to different HBV genotypes by using a newly developed line probe assay. The distribution of HBV genotype was as follows: genotype A alone in 2 (0.6%); genotype B alone in 256 (78.8%); genotype C alone in 10 (3.1%); mixed genotype A and B in 18 (5.5%); genotype B and C in 30 (9.2%); genotype B and D in 1 (0.3%); genotype A and C in 1 (0.3%); and mixed infections of genotype A, B, and C in 3 (0.9%). Clonal analysis confirmed further the existence of mixed genotype infection and recombination between different genotypes. Compared with our previous data, the line probe assay seemed more sensitive than polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay in identifying HBV genotype (98.8% vs. 65.0%) and detecting mixed genotype infections (16.3% vs. 0%). In conclusion, the prevalence of mixed HBV infections is substantially higher in IVDU in endemic areas, and the line probe assay is a useful method for rapid genotyping of HBV, with particular reference to the detection of mixed genotype infections.     

Piretanide-dextran and piretanide-polyethylene glycol interact with high affinity with the Na+ 2 Cl− K+ cotransporter in the thick ascending limb of the loop of Henle

Piretanide blocks the Na⁺ 2Cl^– K⁺ cotransporter protein in the thick ascending limb (TAL) of the loop of Henle reversibly. When tested from the luminal side in isolated perfused cTAL segments it leads to a half maximal inhibition (IC₅₀) of the equivalent short circuit current (I_sc) at a concentration of 10^–6 mol/l. From the basolateral side it has no effect on I_sc up to 10^–4 mol/l. The present study was designed to search for high affinity blockers of the Na⁺ 2Cl^– K⁺ cotransporter with large molecular weight in an attempt to use these macromolecules for antibody-labelling or affinity separation of this transport-protein. Amino-ethyl-dextran or amino-ethyl-polyethylene glycol (M.W. 5kd) were coupled to isothiocyanato-piretanide (ISO-PIR) at room temperature in DMSO. The resulting compounds dextran-sulfonylurea-piretanide (PIR-DEX) and polyethylene glycol-sulfonylurea-piretanide (PIR-PEG) (M.W. 5.38kd) were purified and tested in isolated perfused cTAL segments. IC₅₀ values for ISO-PIR, PIR-DEX and PIR-PEG were estimated from dose response curves after their addition to the lumen or bath perfusate, respectively. ISO-PIR, PIR-DEX and PIR-PEG acted from the lumen side at 3·10^–6, 6·10^–6 and 2·10^–6 mol/l. The inhibitory effect was easily reversible. From the basolateral side no effect for any compound was seen at up to 10^–4 mol/l. In clearance experiments PIR-DEX was given to female Wistar rats as an i.v. bolus (25 mol/kg) and the diuretic urine was collected. After dialysis (exclusion limit 2.5kd) the dialysed urine and the dialysate were tested in isolated perfused cTAL segments. The dialysates had no effect on I_sc, but the dialysed urine inhibited I_sc by 35% from the luminal side. The present data show: High molecular derivatives of piretanide with dextran or polyethylene glycol moieties block the Na⁺ 2Cl^– K⁺ cotransporter in cTAL segments at roughly the same low concentration as piretanide itself. Our data exclude a metabolism of these piretanide compounds in the kidney. Since these macromolecular probes can probably not enter the cell their inhibitory effect indicates that the binding site for piretanide diuretics on the Na⁺ 2Cl^– K⁺ cotransporter is exposed on the surface of the luminal cell membrane.This study was supported by Deutsche Forschungsgemeinschaft Gr 480/9