Effects of 1,3-chelation induced by cis-diamminedichloroplatinum(II) on the stability of DNA duplexes. Several 1,3-intra-strand cross-linked decadeoxynucleotide duplexes, modified with cis-diamminedichloroplatinum(II) (cis-DDP), and their base substitution analogues at the complementary site to the intervening base of the coordination sites, were synthesized and measured for UV-melting profiles to determine melting temperature (Tm) values. The results indicated the thermal stability of the oligonucleotide duplexes containing Pt-induced 1,3-intra-strand cross-linking did not depend on the kind of intervening base of the coordination site but rather on its complementary base. These results may explain the mutagenicity of cis-DDP from a chemical aspect.


Kinetics of the N intermediate and the two pathways of recovery of the ground-state of bacteriorhodopsin. Absorption kinetic measurements at alkaline pH, in which bacteriorhodopsin (BR) is pre-excited by another flash, indicate that a part of the recovery of the BR ground-state is faster than the decay of the N intermediate of the photocycle. This fact proves the existence of a parallel pathway in the late part of the BR photocycle (the decay of Ms into BR), which does not include the N intermediate. We demonstrate that the decay of the Mf intermediate does not lead to any direct recovery of the BR ground-state, and that excitation of N does not form an M-like intermediate. Mf decays directly into the N intermediate, and photoexcitation of N leads to the formation of a red-shifted form, O*. The kinetics of this red-shifted intermediate are also presented.


Sequence analysis of pigeon delta-crystallin gene and its deduced primary structure. Comparison of avian delta-crystallins with and without endogenous argininosuccinate lyase activity. delta-Crystallin is a major lens protein present in the avian and reptilian lenses. To facilitate the cloning of the delta-crystallin gene, cDNA was constructed from the poly(A)+ RNA of pigeon lenses, amplified by the polymerase chain reaction (PCR). The PCR product was then subcloned into pUC19 vector and transformed into E. coli strain JM109. Plasmids purified from the positive clones were prepared for nucleotide sequencing by the dideoxynucleotide chain-termination method. Sequencing two clones, containing 1.4 kb DNA inserts coding for delta-crystallin allowed the construction of a complete, full-length reading frame of 1,417 bp covering a deduced protein sequence of 466 amino acids, including the universal translation-initiating methionine. The pigeon delta-crystallin shows 88, 83 and 69% sequence identity to duck delta 2, chicken delta 1 crystallins and human argininosuccinate lyase respectively. It is also shown that, in contrast to duck delta 2 crystallin which has a high argininosuccinate lyase activity, pigeon delta-crystallin appears to contain very low activity of this enzyme, despite the fact that they share a highly homologous structure. A structural comparison of delta-crystallins with or without enzymatic activity suggested several amino acid replacements which may account for the loss of argininosuccinate lyase activity in the lenses of certain avian species.


Structural relationship between lipases and peptidases of the prolyl oligopeptidase family. In prolyl oligopeptidase and its homologues, which constitute a new serine protease family, the order of the catalytic Ser and His residues in the amino acid sequence is the reverse of what is found in the trypsin and subtilisin families. The exact position of the third member of the catalytic triad, an Asp residue, has not yet been identified in the new family. Recent determination of the three-dimensional structures of pancreatic and microbial lipases has shown that the order of their catalytic residues is Ser, Asp, His, and this fits the order Ser, His of prolyl oligopeptidase. However, there is no sequence homology between lipases and peptidases, except for a 10-residue segment, which encompasses the essential Ser, and for the immediate vicinity of the catalytic Asp and His residues. This comparison identifies the catalytic Asp residue in the prolyl oligopeptidase family. The relative positions of the three catalytic residues in peptidases and microbial lipases were the same and this indicated structural and possibly evolutionary relationship between the two families.


Cloning and expression of a novel mouse somatostatin receptor (SSTR2B). A mouse somatostatin (SS) receptor cDNA was cloned from neuroblastoma x glioma (NG108-15) cells. The sequence is almost identical to that of the mouse SSTR2 receptor [(1992) Proc. Natl. Acad. Sci. USA 89, 251)] but lacks about 300 nucleotides between transmembrane domain VII and the C-terminus. This spliced variant of SSTR2 (designated SSTR2B) encodes a protein which is 23 residues shorter than that predicted from the SSTR2 sequence, and differs in 15 amino acids at the C-terminus. mRNA corresponding to SSTR2B occurs in mouse tissues in higher abundance than that of SSTR2. SSTR2B binds SS peptides with high affinity when expressed in mammalian cells.


Regulation of arachidonate-mobilizing phospholipase A2 by phosphorylation via protein kinase C in macrophages. Stimulation of 32P-labeled macrophages with phorbol ester caused an increase in phosphorylation of the intracellular, high molecular weight phospholipase A2. This increase in phosphorylation was accompanied by an increase in enzyme activity, but led to no detectable shift in the concentration dependence for Ca(2+)-induced activation. The phosphorylated phospholipase A2 could be dephosphorylated by treatment with acid phosphatase, and such treatment also reduced its catalytic activity. Together with previous data, these results indicate that the arachidonate-mobilizing phospholipase A2 is dually regulated by Ca2+ (membrane interaction) and by phosphorylation (catalytic activity).


No evidence for calpain I involvement in fodrin rearrangements linked to regulated secretion. Stimulation of secretion in chromaffin and parotid acinar cells is associated with dramatic rearrangements of the subplasmalemmal cytoskeleton, notably of fodrin and F-actin. It has been proposed that a proteolytic cleavage of fodrin resulting from an activation of the neutral calcium activated protease (calpain) could be responsible for these changes. Using an affinity-purified anti-alpha-fodrin antibody, several cleavage products of fodrin could clearly be detected following incubation of total cell homogenates from chromaffin and parotid acinar cells with purified calpain I. On the other hand, maximum stimulation of secretion of chromaffin cells by nicotine, and of parotid acinar cells by carbachol plus isoproterenol, was not associated with an increased appearance of cleavage products of fodrin. This result is not compatible with the 'proteolytic cleavage' hypothesis.


Genomic organization and full-length cDNA sequence of human collagen X. We have determined the full-length cDNA sequence of the human alpha 1(X) collagen gene by sequence analysis of a genomic clone ERG [(1991) Dev. Biol. 148, 562-572], and of cDNA fragments generated from a reverse transcribed as alpha 1(X) mRNA by PCR. We defined the promoter region, the transcription initiation site and the full-length 5'-untranslated region. We also report the exon/intron boundaries of the transcript and the complete 3'-untranslated region as well as a 3'-flanking sequence containing two additional polyadenylation signals. The promoter region is homologous to chicken and mouse type X promoters within several highly conserved regions. The genomic organization shows high homologies to chicken and mouse.


Deletion of internal twenty-one amino acid residues of Escherichia coli prolipoprotein does not affect the formation of the murein-bound lipoprotein. Mutation pgsA affecting the phosphatidylglycerol phosphate synthesis is lethal for all but certain E. coli strains such as strains deleted for the lpp gene or strains containing unmodifiable prolipoprotein like lppD14. Strain SD312 pgsA3 is tolerant to pgsA mutation, which suggests the lpp alleles in strain SD312 pgsA3 and its parental strain SD12 may be defective. DNA sequence analysis of the lpp genes in Escherichia coli strains SD12 and SD312 pgsA using asymmetric polymerase chain reaction showed that the lpp alleles in these two strains contained a 63 base pair deletion corresponding to the 37th to 57th codons of the wild-type lpp gene. [3H]Palmitate labeling of strains SD12 and SDS312 showed that the mutant lipoprotein in SD12 strain was modified with lipid, while the prolipoprotein in SD312 was not modified. The shortened mature lipoprotein in SD12 and the lipid-modified prolipoprotein in globomycin-treated SD12 were found to be covalently attached to the peptidoglycan, while the unmodified prolipoprotein in SD312 did not form significant amounts of murein-bound lipoprotein.


Surveillance of lower extremity vein grafts. Development of stenosis in lower extremity vein grafts or its anastomotic segments is responsible for most graft failures. While these lesions can be treated by minor procedures, timely identification may improve long-term graft patency. In this review, diagnostic methods that are currently applied for vein graft surveillance, criteria for stenosis and recommendations for intervention are discussed.


Unresolved pulmonary embolism: the value of surgical management with extensive thrombo-endarterectomy. In a small but definite number of patients with pulmonary embolism, either gradual resolution of the embolus does not occur or recurrent showers of emboli follow the acute onset, leading to a state of chronic pulmonary hypertension. Two new cases treated surgically without the use of cardiopulmonary bypass are described. The results were excellent in both cases with relief of the dyspnoea and an improvement in the PO2, a result that has been documented in the follow-up of 2-6 years. The only definite treatment of this chronic obstructive pulmonary hypertension is pulmonary thrombo-endarterectomy.


Non-invasive monitoring of cardiac output changes during aortic cross-clamping for infrarenal reconstruction--a new technique using suprasternal Doppler-derived cardiac output. There is a significant morbidity and mortality associated with elective infrarenal aortic reconstruction. To examine the value of continuous cardiac output monitoring for predicting those at risk, 40 consecutive patients were monitored using Doppler-derived cardiac output. The anaesthetist was blind to all information from the monitor and managed the patients using standard techniques. In 28 patients there were no observed changes, while in seven, cardiac output rose after aortic cross-clamping. In five patients a fall in cardiac output occurred after cross-clamping. No cardiac events or cardiac deaths occurred in the 35 patients who showed a rise or no change in cardiac output. However, there were three cardiac events, including one cardiac death in the group of five patients in whom a fall in cardiac output was observed. It would appear that intraoperative non-invasive Doppler-derived cardiac output monitoring successfully predicts high-risk patients who would perhaps benefit from more intensive pre-, peri- and postoperative care.


Fibro-muscular renal artery disease treated by extracorporeal vascular reconstruction and renal autotransplantation: short- and long-term results. Over a 16-year period (1973-1989), 63 renal autotransplants were performed in 59 patients for fibro-muscular dysplasia (FMD) with renal artery stenoses (42 kidneys) or aneurysms (21 kidneys). About two-thirds of the autotransplants were performed before percutaneous transluminal angioplasty (PTA) was established for clinical use. However, vascular disease at a site or type not suitable for PTA was present in 57 (90%) of the kidneys. Hypertension was the leading symptom in 56 patients, including four in whom renal autotransplantation was performed as an emergency for acute renal artery occlusion or malignant hypertension. Blood pressure returned to normal or improved in 51 (91%) and remained unchanged in five patients (9%) following autotransplantation. Three patients with renal artery aneurysm in whom haematuria and loin pain were the indications for treatment, became asymptomatic following surgical intervention. Bilateral renal autotransplantation was performed synchronously in one and sequentially in three patients. There were no operative deaths, but two kidneys were lost postoperatively in two 2-year-old children owing to renal vascular thrombosis. In the follow-up period (mean 4.3 years), one additional kidney was lost at 3 months owing to progressive FMD. Blood pressure and renal function remained stable in all other patients. Based on the excellent results achieved in this series, it is concluded that extracorporeal vascular repair and renal autotransplantation is a safe procedure for the patient as well as the kidney affected by FMD. The procedure is advocated as an alternative to in situ reconstruction in patients with renal artery disease not accessible to PTA, such as aneurysms and complex branch renal artery stenoses.


Renal artery aneurysm: surgical indications and results. The clinical course of 23 patients with 28 renal artery aneurysms (RAAs) is reported. The RAAs were recorded over a period of 10 years. Thirty-five per cent of the RAAs (eight of 23 patients) were detected during the investigation of hypertension, whereas 26% (six of 23 patients) were discovered incidentally while imaging atherosclerotic arterial disease in the aorto-iliac region by angiography. Twenty-two aneurysms were treated surgically and primary nephrectomy was necessary in one case. The surgical technique used was excision of the aneurysm with bypass grafting in 13 cases (seven Dacron, five vein, one arterial bypass), a running suture following aneurysm excision in four cases and an end-to-end anastomosis in two cases. The results (for a period of 1-10 years) were excellent in all but three cases: two early graft occlusions (vein interposition) and one late occlusion (Dacron bypass) in the course of a re-operation which had become necessary because of a ruptured aneurysm of the gastro-epiploic artery after 3 months. Three of 23 patients were treated by embolisation of four intraparenchymal aneurysms. The follow-up of a non-treated saccular aneurysm showed a total thrombosis of the aneurysm within 4 years and fixed renal hypertension developed later in this patient. We suggest surgical repair of an RAA regardless of its size and the clinical symptoms, in order to prevent microembolism into the renal parenchyma and to avoid the development of fixed renal hypertension. Intrarenal aneurysms can be treated by embolisation to stop severe haematuria thus preserving the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)


Endothelial cell seeding of damaged native vascular surfaces: prostacyclin production. Endothelial cell seeding has been successful in reducing the thrombogenicity of prosthetic vascular grafts in animal and clinical studies. The reduction in thrombogenicity may be attributed to the intrinsic properties of endothelial cells themselves, and their ability to produce anti-thrombogenic mediators such as prostacyclin, and endothelium-derived relaxing factor. Endothelial seeding of damaged vascular surfaces produced during percutaneous transluminal angioplasty and endarterectomy is an attractive possibility due to the excellent attachment characteristics of the sub-endothelial tissue exposed during these procedures. The ability of endothelial seeded damaged vascular surfaces to produce prostacyclin was measured in an in vitro model of vascular injury. Endothelial-seeded damaged surfaces produced significantly higher prostacyclin release than did vessels damaged by balloon dilatation (265.5 pg cm-2 min-1 and 87.5 pg cm-2 min-1 respectively). This study provides evidence that endothelial seeding of damaged native vascular surfaces is technically feasible and that seeding may reduce the thrombogenicity of vascular surfaces following balloon dilatation.


Wound infection after arterial surgical procedures. During the period October 1983 to March 1987, 603 patients who underwent arterial surgical procedures were studied to determine the incidence and treatment of wound infections. Bypass procedures were performed in 395 patients (65.5%), in which autogenous vein was used for 158 grafts (26%), synthetic Dacron for 216 grafts (36%), and umbilical vein for 21 grafts (3.5%). Thrombo-endarterectomies, embolectomies and patch-grafts were performed in 208 patients (34.5%). An Infection Control Nurse examined and registered the wounds. The definition of wound infection used in our study is equivalent to Szilagyi grade II infection. Vascular surgery is classified as clean surgery, the clean wound infection rate being a useful measurement to evaluate preventative measures and surgical technique. Thirty-one patients (5.1%) developed a wound infection as a postoperative complication. The overall incidence of wound complications including haematoma and seroma following arterial reconstruction was 13%. The site of wound infection was predominantly the groin. The most common pathogen was Staphylococcus aureus which was found in 17 patients (2.8%). All infections resolved without further surgical intervention. The influence of possible aetiological factors is considered and the importance of prophylactic antibiotics and good surgical technique is stressed.


Prostacyclin is produced from endothelial cell-seeded grafts: an experimental study in sheep. Endothelial cell seeding might be of value in reducing the thrombogenicity of small-diameter vascular grafts. We investigated the capacity of endothelial cell-seeded grafts to produce prostacyclin and compared this with that of the unseeded graft as well as the native artery. Twelve sheep were operated on with carotid interposition of externally supported knitted dacron grafts. On one side of the neck the graft was seeded with endothelial cells, enzymatically harvested from the left jugular vein. After 3 weeks, three out of 12 seeded grafts, and one out of 12 unseeded grafts were occluded (N.S.). After excision, the grafts were mounted and perfused ex vivo for five 15-min periods. During the last period, arachidonic acid (4 micrograms/ml) was added to the perfusate. The resected carotid artery was used as a control. Prostacyclin was determined as the stable degradation product 6-keto-PGF1 alpha using radio-immunoassay, and expressed as pg mm-2 luminal surface. The native artery had a significantly higher release of prostacyclin than the seeded graft, which in turn had a significantly higher release than the unseeded graft. Histological examination showed weakly positive staining for factor VIII-related antigen on the luminal surface of seeded grafts. Scanning electron microscopy showed endothelial cells with typical endothelial tufts and was evaluated blindly from 10 areas of each graft. The extent of endothelial cell coverage was evaluated and scored from 0 to 2.5. The median score for the unseeded grafts was 0.3 and for the seeded grafts 1.5 (p = 0.008). Prostacyclin production was higher in seeded than unseeded grafts, but did not influence patency in this model.


Revascularisation of distal tibial and pedal arteries. The results of 1062 reconstructive operations performed on the tibial and peroneal arteries in patients with Fontaine stage III or stage IV disease are presented. A group of 121 patients in whom the anastomosis was to the tibial or peroneal artery with no direct flow to the foot, and a group of 59 patients with direct anastomoses to the pedal arteries, are analysed in detail.


The aetiology of vein graft strictures: a prospective marker study. In a prospective series of 74 femoro-popliteal vein grafts (34 in situ and 40 reversed), 22 strictures were identified by duplex scanning in 18 grafts (24.3%). Thirteen strictures were identified in 10 of 40 reversed grafts and 9 strictures were identified in 8 of 34 in situ grafts. Grafts were marked at operation using surgical clips at sites of all valves, tributaries, clamps and venotomies, since these have all been suggested as potential sources of graft strictures. These were prospectively studied as part of a detailed graft surveillance programme by intravenous digital subtraction angiography and duplex scanning. A total of 377 valves, 681 tributaries, 15 clamps and 2 venotomies were identified. Twenty-two strictures were detected in 18 grafts, an incidence of 24.3%, but only one lesions coincided with a specific marked area (a valve site). Duplex examination in 34 in situ grafts identified 10 residual valve cusps in seven grafts. In none of these was there any evidence of turbulence or flow disturbance, and none progressed to form a stricture. It is concluded that there is no correlation between valve sites, tributaries, clamp sites or residual valve cusps and the development of vein graft strictures.


The morphology of recurrent varicose veins. Over an 18-month period, of 444 patients referred for treatment for varicose veins, 95 (21%) had had previous surgery. By means of clinical hand-held Doppler and in selected venographic evaluation these were subdivided into three groups as follows. Type 1:29 of the 95 patients had recurrence through thigh perforators. Type 2:10 patients had developed incompetence through a second saphenous system, in nine of the 10 in the short saphenous having had previous long saphenous surgery. Type 3:46 patients had recurrent sapheno-femoral incompetence and 10 sapheno-popliteal incompetence. A persistent long saphenous trunk in the thigh was present in approximately two-thirds of cases of types 1 and 3. In over half of the type 3 patients saphenofemoral recurrence was by reconstitution of the junction by neovascularisation. These morphological studies demonstrate why there may be an increased risk of recurrence if the long saphenous trunk is not excised at the time of primary surgery.


Intraoperative prediction of ischaemic injury of the bowel: a comparison of laser Doppler flowmetry and tissue oximetry to histological analysis. Intraoperative diagnosis of inadequate colonic perfusion would contribute to prevention of ischaemic colitis after abdominal aortic reconstructions. The aim of this study was to evaluate laser Doppler flowmetry (LDF) and tissue oximetry (TpO2) as predictors of the development of bowel necrosis. Devascularised loops of colon and ileum in anaesthetised pigs were divided into 10-20 mm segments and measurements of laser Doppler flux and TpO2 were performed in each segment. After 7 h of ischaemia the segments were resected for histological and biochemical analysis. In 65 colonic and 58 ileal segments a significantly lower flux was found in segments with necrosis of greater than or equal to 30% of the mucosal thickness compared to segments with necrosis of less than or equal to 10% (p less than 0.01). The discriminant flux value was 50 perfusion units, confirming a previous clinical study. The specificity was 0.96 and the sensitivity 0.94. Flux was inversely correlated to tissue lactate concentration. Significantly lower TpO2 was found in 19 colonic segments with necrosis of greater than or equal to 30% of mucosa compared to 19 colonic segments with necrosis of less than or equal to 10% (p less than 0.01). Using a discriminant value of 5kPa, a specificity of 0.79, and a sensitivity of 0.95 were calculated. In 27 ileum segments no significant difference in TpO2 between different histological groups was found (p greater than 0.30). The results show that LDF and TpO2 can predict ischaemic injury of the colon, and LDF also of the small bowel.


The relevance of posturally induced microvascular constriction after revascularisation in patients with chronic leg ischaemia. In patients with severe chronic lower limb ischaemia, postural vasoconstriction is disturbed, resulting in enhanced skin microcirculatory perfusion on leg dependency. After vascular reconstructive surgery, postoperative oedema formation is frequently seen. In 31 patients with leg ischaemia undergoing revascularisation we investigated whether and, if so, for how long after surgery postural vasoconstriction would take to recover, and whether disturbed vasoconstriction correlates with the occurrence of postoperative oedema. Capillary microscopy and laser Doppler fluxmetry were used to assess nutritional and total skin perfusion, respectively. The measurements were performed before and up to 37 days after surgery. After revascularisation, the mean ankle blood pressure index rose from 40 to 82%. All patients, except those with persistently disturbed vasoconstriction showed improved microcirculatory parameters. Postural vasoconstriction was restored in 24 patients, occurring approximately on the eighth postoperative day. All patients who failed to recover vasoconstriction developed postoperative oedema. This study shows that the disturbance in postural vasoconstriction can be reversible, probably due to recovery of arteriolar smooth muscle tone, and that patients with persistently disturbed postural vasoconstriction, are prone to develop postoperative oedema.


In situ saphenous vein bypass surgery in diabetic patients. From 1986 through to 1990 a total of 483 consecutive in situ infra-inguinal vein bypass procedures were performed in 444 patients, of whom 112 (25%) were diabetics (57 insulin dependent diabetes mellitus and 55 non-insulin-dependent diabetes mellitus). Based on a prospective vascular data registry this material was analysed to determine the influence of diabetes on the outcome. Preoperative risk factors were equally distributed among diabetic and non-diabetic patients, except for smoking habits (diabetics: 48%; non-diabetics: 64%, p = 0.002) and cardiac disease (diabetics: 45%; non-diabetics: 29%, p = 0.005). Indication for surgery was gangrene or ulceration in 57% of diabetics, as opposed to 36% in non-diabetic patients (p = 0.0002). A femoro-popliteal bypass was performed in 18% of patients, whereas 82% received an infrapopliteal procedure, of which 42% were to the distal third of the calf or foot. Diabetic patients had a significantly lower distal anastomosis than non-diabetic patients (p = 0.0001). The overall 3-year primary and secondary patency rates were 58 and 64%, respectively, with no differences between non-diabetics, non-insulin-dependent diabetics and insulin-dependent diabetics. Neither did limb survival differ among the three groups. However, the rate of minor amputations was significantly higher in insulin-dependent compared with non-insulin-dependent diabetics, who in turn had a higher rate than non-diabetic patients (p less than 0.00001). A markedly decreased survival rate was found in diabetics (p less than 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)


The importance of vascular surgical audit to surgeons, patients and purchasers. This audit of vascular surgical operations from a Teaching Hospital vascular unit was facilitated by computerised data collection. A total of 2075 patients had 2628 procedures over the 6-year period 1985-1990. Vascular workload increased by 50% to almost 350 primary reconstructions per year. In Bristol, vascular patients now occupy 19% of surgical bed-days. Mean stay for vascular patients is twice as long as for general surgical patients (14 days vs. 6 days) and three times as long for patients having secondary reconstructions (18 days) or those with critical limb ischaemia (21 days). Mortality and reoperation rates remained relatively constant throughout the study period. The overall mortality rate was 10.4%, being highest for ruptured aortic aneurysms (31.9%) and lowest for carotid endarterectomy (1.7%). Early reoperation for the complications of vascular reconstruction was required in 9.1% cases, being most frequent for femoro-tibial grafts (26.1%) and least for carotid endarterectomy (1.7%). Vascular surgery is expensive, time consuming and on the increase in Bristol. Comprehensive computerised audit of vascular operating is essential both for patients who benefit from the maintenance of high standards, and also for surgeons whose results this year will determine the cost and volume of next year's contracts.


Re-intervention after vascular surgery for critical leg ischaemia. Re-operation after arterial bypass in the leg is common, may be seen as failure by many and can appear expensive to budget holders. Secondary reconstruction may not be undertaken for these reasons. The indications for and outcome of further intervention have been studied in 395 primary presentations with critical leg ischaemia, all of whom underwent arterial reconstruction. During the study period the primary amputation rate was 3%, and 10% of reconstructed patients presented with skin necrosis or gangrene. One hundred and twenty-nine reconstructions (32%) were to crural vessels in the lower third of the calf. Mean follow-up was 3 years, 1 month mortality was 2% and overall mortality 20%. One hundred and seventy-three (44%) patients required further intervention: 118 (30%) for recurrence of ipsilateral ischaemic symptoms and 55 (14%) in the presence of a patent primary graft (mostly operations on the contralateral leg). A total of 695 secondary operations were required over follow-up, a mean 1.75 additional operations per patient per 3 years. Following recurrence of ischaemia, graft revision or secondary revascularisation was undertaken in 98 of 118 (84%) legs whilst the remaining 19 legs had an amputation performed after primary graft failure. Secondary reconstruction was successful in salvaging 63 limbs to mean follow-up, a 64% success rate from revisional surgery. At mean follow-up 339 of 395 limbs remain viable (86% limb salvage), secondary graft patency is 79% and primary graft patency 63%. Failure to re-intervene after primary graft failure would reduce limb salvage at 3 years to 70% with corresponding loss of 63 legs.(ABSTRACT TRUNCATED AT 250 WORDS)


The management of small abdominal aortic aneurysms: a computer simulation using Monte Carlo methods. Many small abdominal aortic aneurysms can now be identified by ultrasound screening and it is necessary to decide whether the risks of enlargement and rupture justify elective surgery. A computer simulation of the behaviour of small aneurysms has been constructed using Monte Carlo methods to model patterns of enlargement and rupture. The effect of policy with regard to the observation and timing of intervention has been evaluated for different patient groups. The results demonstrate the value of early intervention in otherwise fit patients with expected operative mortality rates of 5% or below, whereas, for older patients (over 70 years old) 6-monthly screening and operation if the aneurysm exceeds 5 cm is suggested. Higher risk patients with expected operative mortality of over 10% may be better treated conservatively up to an aneurysm diameter of 7 or 8 cm. The method used for simulation is flexible, being easily adjusted to take account of new information, and may have applications in other areas of clinical decision making.


Endoscopic transthoracic sympathectomy: experience in the south west of England. Thoracic sympathectomy has an established role in the management of primary palmar and axillary hyperhidrosis, Raynaud's phenomenon and occlusive vascular disease. Potential problems with traditional surgical approaches to the sympathetic chain include poor exposure, risk of damage to adjacent structures and postoperative pain. A minimally invasive endoscopic approach helps to overcome these problems. Using this technique, 45 procedures have been performed on 26 patients in two districts in the South West of England over the past five years. Follow-up information was available for 39 procedures. All 27 procedures for hyperhidrosis and both for occlusive vascular disease have produced a long-term improvement. Nine of the 10 procedures for Raynaud's phenomenon have also produced some degree of long-term improvement. Complications included four asymptomatic pneumothoraces, two patients with temporary unilateral Horner's syndrome and two instances of intercosto-brachial numbness. On the positive side, patients expressed satisfaction with the efficacy, rapid recovery and small unobtrusive scars produced by the procedure. Endoscopic transthoracic sympathectomy is effective, safe and well accepted by patients and we believe is now the method of choice for this procedure.


Gas gangrene following intra-arterial injection of oral medication in a drug abuser. We report a patient in whom intra-arterial injection of oral medication led to the development of fulminating gas gangrene and death, despite the initial clinical symptoms being minor. We believe that prophylactic antibiotics should be administered to patients following intra-arterial injection of oral medication especially if immunocompetence, such as from human immunodeficiency virus (HIV) infection, is likely.


Peritonitis causing acute limb ischaemia. A patient presented with an acutely ischaemic leg and mild abdominal pain. Arteriography showed an iliac occlusion and some distal occlusive disease. At laparotomy a perforated gastric ulcer was found, and by the end of this operation the foot was well perfused. This case exemplifies the serious reduction in limb blood supply which can be caused by an acute illness, without thrombosis of vessels. It emphasises the importance of general assessment and treatment of any associated acute condition, in cases of acute limb ischaemia.


[Treatment of pituitary adenomas].

[Treatment of pituitary adenomas]. There has been a dramatic development in the treatment of pituitary adenomas during the last two decades. The main factors which led to this development were the introduction of transsphenoidal surgery, the development of new imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) and the introduction of newer dopaminergic agents. Present status of the treatment of pituitary adenoma is reported here. This report is based on the experiences of 381 cases of pituitary adenomas treated at the Department of Neurosurgery, Hiroshima University School of Medicine within the last 16 years. There are some problems which have to be solved in order to achieve further development in the treatment of pituitary adenomas. Our experience in this field and a need for future development are listed below. 1) The transsphenoidal adenomectomy gives high cure rates in cases of micro and expansive prolactinomas and growth hormone secreting adenomas. 2) Results of the transsphenoidal surgery in cases of ACTH secreting adenomas is not satisfactory. In order to get higher cure rate, a more elaborate operative techniques and an introduction of more effective drug therapy are needed. 3) Further safety and curability in pituitary surgery will be achieved by the exploitation of new imaging modalities such as MRI.


[Biology of trophoblast and its endocrinological profiles]. The trophoblast of human placenta is composed of syncytiotrophoblast (S-cell) and cytotrophoblast (C-cell). C-cell displays proliferative properties, while S-cell displays little potential for proliferation. A close similarity between cytologic localization of myc product and [3H]thymidine labeling suggests that myc expression is linked to trophoblast proliferation. In situ hybridization with cDNA probes revealed that mRNA expression of hCG alpha and hCG beta are initiated before syncytial formation, whereas hPL mRNA is expressed only in fully differentiated S-cell. EGF and EGF receptor (EGF-R) in 4-5 weeks placenta were localized to C-cell, whereas EGF and EGF-R in 6-12 weeks placenta were localized to S-cell. Consistent with these findings, EGF exerted gestational age dependent dual action on early placenta: one was to stimulate trophoblast proliferation in 4-5 weeks placenta and the other was to stimulate differentiated trophoblast function in 6-12 weeks placenta. An optimal dose of thyroid hormone stimulated progesterone, estradiol, hCG and hPL production in early placental tissues. Furthermore, women with unfavorable outcome of threatened abortion had lower T4, T3, free T4 and free T3 levels, as compared to women with favorable outcome. These data imply a role for thyroid hormone in maintaining early pregnancy. On the other hand, progesterone selectively inhibited hCG (alpha, beta) mRNAs expression and decreased hCG secretion in normal placental tissues, whereas choriocarcinoma did not respond to progesterone. This suggests that inhibitory regulation of hCG synthesis in choriocarcinoma is different from normal placenta. Characterization of choriocarcinoma hCG revealed that there are striking differences in carbohydrate structures between normal hCG and choriocarcinoma hCG. Sialic acid content in choriocarcinoma hCG was extremely lower compared to that in normal hCG. The biochemical detection of the alteration in hCG sugar chains is useful for early diagnosis of choriocarcinoma.


[Identification of a 3' splice site mutation in the thyroglobulin gene in a case of congenital familial goiter]. A case of congenital familial goiter with impaired thyroglobulin (Tg) synthesis has been reported. The patient is the fifth in a family of six children, three of whom have a goiter. The parents are cousins. The patient's thyroid function tests showed low T4 (1.0 microgram g/dl) and free T4 (0.2 ng/dl), normal or slightly increased T3 (1.8 ng/ml) and free T3 (7.4 pg/ml), and high TSH (57 micrograms U/ml). Serum Tg was 5.1 ng/ml (normal less than 30). The thyroidal 123I-uptake was 59.8% before and 54.5% after perchlorate test. Gel filtration with Bio-Gel A 5m demonstrated the presence of albumin-like protein probably iodinated as a major protein in the thyroid and very low content of Tg which was smaller than the normal 19S Tg. Histologically microfollicular adenoma and negative Tg immunostaining were the dominant findings. Segregation of Tg alleles in the family was studied by Southern blotting with a probe revealing a diallelic RFLP. The results demonstrated that the affected siblings had received the same alleles from both parents and were homozygous for the RFLP. Northern blotting analysis of the goiter RNA with a Tg probe revealed that, whereas the amount of Tg mRNA was normal, its size seemed slightly reduced. PCR amplification of Tg mRNA as six overlapping cDNA fragments demonstrated that a 200bp fragment was missing from the 5' region of the goiter mRNA. Subcloning and sequencing of the cDNA fragments, and of the patient's genomic DNA amplified from this region, revealed that this aberrant splicing is due to a cytosine to guanine transversion at position minus 3 in the acceptor splice site of intron 3. The presence in exon 4 of a putative donor tyrosine residue (tyr 130) involved in thyroid hormone formation provides a coherent explanation of the hypothyroid status of the patient. To our knowledge, this is the first identified mutation responsible for congenital familial goiter in humans.


[Metastatic carcinoma of the sigmoid colon to the thyroid gland]. A case of metastatic thyroid cancer from sigmoid colon cancer is presented. A 52-year-old woman had a sigmoidectomy due to adenocarcinoma of the sigmoid colon in April 1988. Serum carcinoembryonic antigen (CEA) levels gradually rose from July 1990 along with multiple metastatic lesions which appeared in the lung. They were resected in January 1991. Two months later the subject noticed a painless and firm lump on the left anterior neck. She was found to have a solitary mass in the left thyroid lobe. Thyroid function remained within normal range. Cytological findings obtained by fine-needle aspiration biopsy showed tall columnar carcinoma cells with an acinar pattern. Subtotal thyroidectomy was performed, and histological examination revealed metastatic adenocarcinoma from colon cancer. Immunohistochemical staining by anti-CEA was positive but anti-thyroglobulin was negative.


[Characterization of thyroglobulin in a patient with functioning and non-functioning benign thyroid tumors]. The chemical and immunological properties of thyroglobulin (Tg) in tissue obtained from a patient co-existed with two types of thyroid tumors, i.e., functioning and non-functioning, and were compared with the properties of Tg that was isolated from adjacent peripheral tissue. In the present observations, the Tg content was markedly increased in the non-functioning thyroid tumor. On the other hand, the Tg content in the functioning tumor was at the normal level. The iodine content of Tg was significantly lower in the non-functioning tumor than in peripheral tissues. Affinity with Lectins differed among Tg preparations, suggesting that the carbohydrate chain in the Tg was different in each nodule in a single individual.


Relationship between dietary retinol and alpha-tocopherol and lipid peroxidation in rat liver cytosol. The effects of retinol and alpha-tocopherol-deficient and supplemented diets on the cytosolic concentration of thiobarbituric acid reactive substances (TBARS) in rat liver have been studied. Physiological lipoperoxidation (LPO) was observed in liver cytosol of control rats (TBARS = 0.315 +/- 0.034 nmol of MDA equivalents/mg of liver cytosolic proteins). In retinol-deficient diets there was a decrease in retinolaemia and the absence of retinol in liver cytosol while cytosolic TBARS increased significantly (P less than 0.001). Vitamin E was not found in cytosolic fractions, except in alpha-tocopherol-supplemented diet rats. alpha-Tocopherol-deficient diets induced an absence of vitamin E in the serum and cytosolic TBARS were increased compared to controls (P less than 0.001). Supplementation of the diet with retinol and alpha-tocopherol or both in combination induced a significant decrease in liver cytosolic TBARS (P less than 0.001). Finally the combination of low dietary supplementation with retinol and alpha-tocopherol (ten times the normal diet each) induced the maximum anti-LPO effect.


An improved olive oil overall migration test for plastics using Karl Fischer titration. Karl Fischer titration has been used to eliminate the need to humidity-condition food contact plastics under test for overall migration into olive oil. The water content of the oil is measured before and after the migration test. This direct measure of the loss (or uptake) of water by the test plastic is then used in calculations of the overall migration. The use of Karl Fischer titration gives faster analysis with reduced labour input. The time savings varied from a few days to several weeks depending on the type of plastic. Karl Fischer titration is particularly useful in the high temperature testing of polar plastics where incomplete humidity conditioning can lead to erroneous results. The technique should be equally valuable when employing sunflower oil or the triglyceride HB307 in place of olive oil.


The effect of microwave energy on specific migration from food contact plastics. Experiments have been carried out with (a) microwave treatment of plastics followed by migration testing using the food simulant, olive oil, and (b) microwave treatment of plastics in direct contact with an organic extractant (iso-octane). In neither of these complementary approaches was there evidence of any difference in migration from plastics that had been microwave-treated compared with plastics that had received an equivalent thermal treatment. Five plastics commonly employed in microwave applications were tested and oligomers, plasticizer, antioxidant and volatile contaminants were monitored as representatives of typical migration species.


N-nitrosamine and mutagenicity formation in Chinese salted fish after digestion. Salted and dried fish (Nemipterus virgatus), acquired from Hong Kong, was treated with 0.43-110 mM nitrite during in vitro digestion using gastric enzymes and the volatile N-nitrosamine content and mutagenicity on Salmonella typhimurium TA100 assayed without concentration. N-Nitrosodimethylamine (NDMA; the only nitrosamine detected) formation was second order in nitrite concentration. When 10 g of fish was treated with 6.96 mM nitrite, 394 nM NDMA was formed. Thiocyanate was catalytic for NDMA formation at nitrite concentration greater than 0.87 mM and when the ratio of thiocyanate to nitrite was greater than 1. Approximately a 50% inhibition in NDMA formation by ascorbic acid was seen when the ratio of ascorbate to nitrite was approximately 2 or greater and the nitrite concentration was 1.74 mM. Mutagenicity increased with increasing nitrite concentration but the addition of thiocyanate did not increase mutagenicity over nitrite alone. Ascorbate increased mutagenicity even though NDMA formation was inhibited. Even at nitrite concentrations greater than 100-fold higher than expected in vivo, there was insufficient NDMA formed to account for the observed mutagenicity. These data do not exclude the possibility that the observed mutagenicity was due to non-volatile N-nitroso compounds, however, this possibility seems unlikely given the effects of ascorbate and thiocyanate which would be expected to inhibit and enhance non-volatile N-nitroso compound formation.


Review of the occurrence and formation of non-volatile N-nitroso compounds in foods. A review of the literature published prior to July 1991 covers the occurrence and formation of non-volatile N-nitrosamines occurring in foods and beverages. The presence of identified volatile and non-volatile N-nitrosamines accounts for less than 10% of the total apparent N-nitrosamine concentration. N-Nitrosoproline and N-nitrosothiazolidine-4-carboxylic acid are the most commonly identified non-volatile N-nitrosamines in the diet. Non-volatile N-nitrosamines account for 12 of the 21 currently identified N-nitroso compounds in foods and beverages.


Sensory symptoms of multiple sclerosis may be clues to causation: review and a hypothesis. Sensory signs and symptoms occur in 75 percent of patients with multiple sclerosis (MS), ranking second to coordination defects. After intensive research into MS began in the 1930s, most attention was devoted to central nervous system demyelination. Some studies were done on peripheral nerve, but none on the sensory ganglia of the cord or brain. An original and thus far uninvestigated hypothesis is presented here that an unidentified organism might reside and multiply in various dorsal root and cranial sensory ganglia (DRG). This review summarizes the sensory signs and symptoms of multiple sclerosis, traces the embryology and physiology of DRG, and describes the present day research status of human demyelination produced by a number of viral infections. If the infectious agent for MS exists in a latent state in the DRG, low spinal fluid viral titers and sporadic cultures of certain viruses might be explained by the occasional contact of spinal and cranial sensory ganglia with spinal fluid flow. Research techniques available to test the hypothesis are as follows: various heating reactions and evoked potential testing of patients, and viral hybridization-transcription techniques applied to DRG obtained at autopsy. The "Decade of the Brain" became law on July 25, 1989, when President Bush signed Joint House Resolution 174. The forward looking declaration calls upon citizens and scientists alike to dedicate themselves for the next ten years to the task of eliminating various neuropsychiatric diseases that decimate many populations. High on the list is multiple sclerosis (MS), the subject of a new hypothesis presented here.(ABSTRACT TRUNCATED AT 250 WORDS)


Deoxynivalenol in wheat and maize flour reference materials. 1. An intercomparison of methods. To provide a basis for the certification of wheat and maize flour reference materials containing deoxynivalenol, a series of three preliminary intercomparisons of methods was carried out between 1985 and 1988. The first intercomparison, involving 10 laboratories was designed to examine the determinative step and used a solution of deoxynivalenol in ethyl acetate and a spiked wheat extract solution. The second intercomparison involving 13 laboratories established minimum extraction times for naturally contaminated samples, demonstrated the absence of matrix effects in purified extracts and showed that there was no evidence of differences in the use of any of three different end determinations. The third intercomparison involving 15 laboratories used naturally contaminated cereals and acted as a preliminary to the final certification exercise. Over a period of four years there was a steady improvement in the range of results submitted by participants thought to be due to the application of improved analytical methods, increased expertise in the analysis and through experience gained through the intercomparisons.


Studies into the transfer and migration of phthalate esters from aluminium foil-paper laminates to butter and margarine. Retail samples of Canadian butter and margarine wrapped in aluminium foil-paper laminate were found to contain dibutyl, butyl benzyl and/or di-2-ethylhexyl phthalate (DBP, BBP, DEHP) as packaging migrants at levels up to 10.6, 47.8 and 11.9 micrograms/g, respectively. These phthalates were determined by capillary gas chromatography with flame ionization detection (GC-FID) after clean-up of the separated oil by sweep co-distillation. The phthalate esters found in the contacted butter or margarine were also found in the contacting wrappers. They were determined in wrapper extracts by liquid chromatography with diode array detection or by GC-FID. Analysis of unused wrappers showed 76-88% of the total DBP and DEHP to be present on the foil (outer) surface as a component of the protective coating (washcoat). The remainder of the DBP and DEHP was found on the food-contacting paper surface, presumably by transfer from the outer to inner surface during storage in tightly wound rolls, although transfer of phthalate esters, if present in the paper-foil adhesive, cannot be ruled out. Food-contacting surface concentrations of DBP and DEHP were found to be 2.4 to 4.7 and 2.8 to 3.6 micrograms/cm2, respectively. Samples of each packaging component: paper, foil, adhesive, washcoat and inks were analysed for phthalate esters and only the washcoat was found to contain phthalate esters.


Clinical applications of magnetic resonance angiography. Recent technical advances in magnetic resonance imaging (MRI) now allow for the noninvasive study of blood flow in vessels, or magnetic resonance angiography (MRA). We describe several case reports involving the use of MRA and discuss its advantages in evaluating patients for carotid artery stenosis, intracerebral aneurysms, and arteriovenous malformations (AVMs).


A preliminary study of the bioavailability of iron- and zinc-glycine chelates. Groups of rats were fed diets containing marginal levels of Fe and Zn as glycine chelates (tradename 'Chelazome', Albion Laboratories, Verona, New Jersey, USA), or the same level of mineral as ferrous sulphate or zinc carbonate. The Fe diets were fed to weanling rats for 4 weeks and the Zn diets to young adult rats for 5 weeks. Blood Hb concentrations were significantly higher in the group fed Fe-chelazome than ferrous sulphate, 149 and 128 g/l respectively (P less than 0.001), but PCV and liver Fe concentrations were similar between the two groups. No difference in plasma Zn, pancreas, testes or femur Zn concentrations were observed between the two Zn groups, indicating that Zn-chelazome has no advantage over zinc carbonate. The results of this preliminary study indicate that Fe-chelazome has a higher bioavailability than ferrous sulphate and merits further study.


Quality assurance and continuous quality improvement: history, current practice, and future directions. Quality Assurance (QA) provides opportunities for physicians and allied health professionals to improve patient care and disease outcomes. Its goals are increased efficiency and efficacy in healthcare. QA activities are based upon objective criteria and systematic review and make important contributions to the effectiveness of hospitals and other care facilities. Successful programs help to maximize health status of patients while minimizing resource utilization. Beginning in 1917, early QA efforts were often informal and subjective but now include standards for QA and strategies for monitoring and evaluating patient care. Central to its new "Agenda for Change," the Joint Commission on Accreditation of Healthcare Organizations has embraced the concept of continuous quality improvement (CQI). This moves the focus of review away from department- or practitioner-specific activities and toward a "systems" form of evaluation. CQI is rooted in patient-care realities, is easy to implement, is based upon scientific assessments, and solves practical problems in an incremental and ongoing fashion.


Leaching of aluminium from aluminium dishes and packages. A study was carried out of the leaching of aluminium from aluminium cooking vessels and packages. Very small or undetectable levels of aluminium leached from packaging materials into foodstuffs. In boiling tests with neutral porridge no migration of aluminium into the test matrix was observed from the pan. When boiling milk, the leaching of aluminium was 0.2-0.8 mg/kg. The aluminium content of tap water in aluminium pans when reaching boiling point was 0.54-4.3 mg/l and increased with increasing boiling time to 6.3-17 mg/l. Aluminium dissolved in foods based on acidic fruit juice rose to levels of 2.9-35 mg/kg when the foods were boiled in aluminium pans. Steaming of currant berries in an aluminium vessel gave aluminium concentrations of 19-77 mg/kg in the resulting juice. The highest aluminium concentration of 170 mg/kg was measured in rhubarb juice prepared in the steaming vessel. Aluminium dissolved in water to levels of 0.81-1.4 mg/l when heated for the first time in new coffee percolators. The aluminium concentration of water heated in older percolators was 0.09-0.78 mg/l.


Tetrahydro-beta-carboline carboxylic acids in smoked foods. This paper reports for the first time in smoked foods the presence of three tetrahydro-beta-carboline carboxylic acids. One of these, 1-hydroxymethyl-tetrahydro-beta-carboline-3-carboxylic acid, which is derived from the interaction of tryptophan and glycolaldehyde, and which has not previously been reported in foods, was observed in 20 samples at levels up to 444 micrograms/kg. The corresponding products which are derived from tryptophan and formaldehyde or tryptophan and acetaldehyde were found respectively in 28 samples at levels up to 22 mg/kg and in 16 samples at levels up to 881 micrograms/kg. Greater concentrations were generally found in those smoked foods having a lower pH value and produced by using a longer fermentation or maturation. Only 1-methyl-tetrahydro-beta-carboline carboxylic acid (156-574 micrograms/kg) was found in the four unsmoked samples analysed.


Lead contamination during domestic preparation and cooking of potatoes and leaching of bone-derived lead on roasting, marinading and boiling beef. Lead concentrations were measured in boiled, mashed potatoes and in baked potatoes that had been prepared and cooked in domestic kitchens. Levels of lead in the boiled, mashed potatoes ranged from below the 1 microgram/kg limit of detection up to 18 micrograms/kg with a mean of 6 micrograms/kg (wet weight). In the large majority of cases the lead in the tap water was the predominant source of the metal. Higher amounts of lead (range 11 micrograms/kg to 56 micrograms/kg, mean 27 micrograms/kg) were present in baked potatoes and this was attributed to soil adhering to the potato skin. The extent of leaching of lead from bone during cooking has also been investigated. For beef stocks there was little evidence to suggest that significant migration of bone lead occurred. For beef casseroles, marinaded in red wine, some leaching did occur from beef joints containing elevated amounts of bone lead; however the levels were all below 350 micrograms/kg and, on average, less than double that found in casseroles prepared from normal joints where the bone lead levels were an order of magnitude less.


Comparison of HPTLC and HPLC procedures for the determination of certain xenobiotic residues in apples and pears. HPTLC was used to check for residues of benomyl, carbendazim, ethoxyquin and thiabendazole in apples and pears. The method used showed good precision with a percentage coefficient of variation of less than 5%; recoveries were always greater than 90%. The limits of determination using HPTLC were always at least four times lower than Italian statutory limits. Selectivity with respect to other matrix components was excellent for all fruit varieties tested. Comparison with HPLC confirmed the validity of the results.


Survey of animal livers for vitamin A content. Retail samples of livers from calf (23), ox (18), lamb (17), pig (15), chicken (16) and turkey (1) were analysed to determine levels of vitamin A (all trans-retinol) and to aid assessment of the effects of using vitamin supplemented compound feedingstuffs for livestock. For comparison, 22 liver samples from lambs reared on diets not containing vitamin-supplemented compound feedingstuffs and four samples of liver from ox which had received supplemented feed but not during the last four months prior to slaughter were also analysed. The chosen method of analysis utilized saponification, solvent extraction and normal-phase high performance liquid chromatography with fluorescence detection. For all species analysed, the levels of vitamin A ranged from 10 to 1100 mg/kg, with all but seven at or below 400 mg/kg. For lamb and ox livers, the mean levels were 310 mg/kg and 200 mg/kg respectively for retail samples. The mean levels were 220 mg/kg (lamb) and 120 mg/kg (ox) in liver samples from animals fed controlled diets. The results are of the same order as those reported over recent years.


Total diet studies: the identification of core foods in the United States food supply. Some total diet studies are based on the selection and analysis of core foods in a national or regional food supply. One way to select core foods is by computerized evaluation of the daily food intakes reported by subjects participating in national food consumption surveys. The foods consumed by the population groups of concern may be aggregated into core food groups. The foods within each group may be ranked according to daily intake and weight percentage of the total diet. The food that best represents each group may then be identified as a core food, and the daily consumption levels for each food group may then be assigned to the core food representing the group. Consumption levels may be determined for the specific age-sex categories of concern. To assess the representativeness of core foods identified in this manner, the food composition database of the national survey may be used to determine nutrient intakes based on the full range of foods in the database versus nutrient intakes based on the core foods.


Implementation of the Haemophilus B vaccine for infants by family physicians. This study surveyed the members of the Department of Family Practice in a community hospital regarding the implementation of the newly recommended immunization protocol using Haemophilus Influenzae B Vaccine (HbOC) for infants at 2, 4, and 6 months of age. The purpose was to assess the ability of the physicians to alter their established practices in a timely fashion. The results show that initially 38/66 (58 percent) of the family physicians who care for infants and children were using the new vaccine already (eight to 10 weeks after FDA release). An additional 11 (17 percent) had begun using the vaccine by a second interview four weeks later. Another six (nine percent) responded to a call by a family practice resident. The remaining 16 percent preferred to await governmental regulations or did not respond to interview. Despite uncertain communications to family physicians in this community, the majority were aware of and adapted readily to new immunization recommendations. Prompt notification of all physicians regarding important new vaccine protocols can have a significant impact on the health of infants and children.


Proposal for an international interface standard for food databases. A database interface standard incorporating the food description language LANGUAL is under development to allow international exchange of food composition, food consumption, and other food-related data. The first step in this project is the refinement and implementation of a schema for the interface standard. This schema includes descriptive terms for LANGUAL factors and other aspects of foods. The second step is the development of a repertoire of personal computer programs for retrieval of food data, using the standard interface. The third step calls for the dissemination of the results of this project to an international audience through demonstration projects for international symposia and pilot tests for scientific applications.


Delaware Emergency Medical Services System: cardiac resuscitation. The Delaware EMS system has been in existence for 20 years. Initially begun as one paramedic unit serving New Castle County, it now comprises 15 units in a statewide system. The goal of this report is to detail the EMS system's impact on prehospital cardiac resuscitation and airway management. Emergency Medical Services (EMS) encompass all aspects of managing a sick or injured patient prior to arrival to the hospital. From the time a patient dials 911 until they arrive in the care of a doctor in an emergency room, the EMS system provides initial medical evaluation and care as well as transportation to the hospital. The components of Delaware's EMS system include: 1. Bystanders--the public is often called upon to perform CPR until trained rescuers arrive. 2. Medical Dispatchers--they receive incoming 911 calls and determine the personnel needed. 3. First responders--ambulance crews trained in basic life support (BLS). 4. Second responders--ambulance crews trained in advanced life support (ALS), paramedics. 5. Medical Control--doctors who are in radio contact with paramedics to provide medical advice.


A preliminary diagnostic and treatment protocol. The objectives of the preliminary diagnostic and treatment protocol are 1. To reveal retention or resistance form deficiencies. 2. To reveal need for augmentive periodontal crown-lengthening surgical procedures. 3. To evaluate pontic form for the existing space. 4. To preplan occlusal plane deficiencies and methods of corrective treatment to establish Curve of Spee. 5. To preplan occlusal scheme, i.e., canine guidance, group function, mutually protected occlusion, and cross-bite conditions. 6. To aid in preplanning sequence of treatment and method of preservation of occlusal vertical dimension. 7. To serve as a visual aid for discussion of treatment recommendations with patient prior to actual treatment. 8. To act as a medicolegal record to document the clinician's pretreatment planning in complex treatment situations for possible use in peer review or litigation. 9. To aid in fabrication of an elastomer reduction guide for use during crown preparation. 10. To aid in fabrication of a vacuum-formed template for provisional restoration of crown and abutment teeth after preparation.


Clinical decision analysis in fixed prosthodontics. Structured clinical decision analysis in dentistry in fixed prosthodontics, as in any branch of dentistry, allows the practitioner to think through more clearly the problems at hand based on the clinical data and extenuating factors presented by the patient. This discipline of decision making is intended to complement the experience level and educational background of the clinician in assisting him or her through the decision process. Additionally, CDA helps the clinician define not only the pre-existing condition of the patient prior to irreversible therapy, but also which treatment strategies may best be suited for that individual over an extended period. The systematic nature of decision analysis stimulates the focusing of one's attention on those factors considered to be germane to the overall complexity of the case and, at the same time, excluding those factors having little or no influence on its final outcome. With further implementation of computerized databases and procedural outcome probabilities based on clinical and laboratory studies as well as the clinical experience of those choosing to use it, the future for structured, formalized clinical decision analysis seems quite promising.


Prosthetic rehabilitation in temporomandibular disorder and orofacial pain patients. Clinical problem solving. Good clinical decision making represents an integral part of quality care. A definition of the dental problem and its significance from a dental point of view, in combination with a good working hypothesis of the nature of the concurrent TMD condition are prerequisites of any successful clinical problem solving. It is hoped that, with time, we will be in a position to call upon hard data on the probability and utility of successful outcome for each treatment alternative. This will bring the needed structure and scientific validity to a terribly complex albeit clinically important problem.


Pontic design and localized ridge augmentation in fixed partial denture design. The endpoint of fixed prosthesis design is an esthetic and functional pontic that is compatible with soft-tissue health. In the posterior segment, where esthetics is not as critical, a sanitary pontic form is most compatible with function and hygiene. In the maxillary anterior region, a properly contoured modified ridge-lap pontic design constructed of glazed porcelain most readily fulfills both the esthetic and physiologic requirements. Although the ovate pontic form may satisfy esthetic demands to a greater degree, this is often at the expense of underlying soft-tissue health. In maxillary edentulous regions, ridge deformities may preclude a good pontic fit and esthetic result and dictate the need for surgical augmentation of the collapsed ridge. Selection of the appropriate surgical procedure and graft material depends on the nature and extent of the defect and availability of donor tissue. The subepithelial graft employing the tunnel approach is appropriate when augmentation in only a labial dimension is necessary. When the employing the trapdoor approach or full thickness gingival onlay graft may be employed. In large defects, sequential grafting procedures may be necessary to achieve the desired result. An esthetic and functional result can be attained through proper execution of an appropriate surgical technique and adherence to the principles of proper pontic design.


Orthodontic adjunctive treatment in fixed prosthodontics. The purpose of this article has been to increase the restorative dentist's appreciation for the rationale justifying preprosthodontic orthodontic treatment. It has not been intended to identify all the specific indications for the use of orthodontic treatment to enhance prosthodontic treatment nor has it been intended as a reference to assist the restorative dentist in placing and using orthodontic appliances. Figure 12 illustrates a typical case in which the combination of orthodontic and prosthodontic treatment resulted in a more favorable outcome than prosthodontic treatment alone. When planning prosthodontic treatment, the dentist should embrace a dynamic view of tooth position and determine whether restorative treatment can be enhanced by tooth movement. Improved tooth position can eliminate potentially pathologic occlusion and create a healthier periodontal environment that is easier to maintain. In addition, it permits the dentist to place restorations that often require less natural tooth reduction during preparation, and that are more esthetic, functional, stable, and durable. Orthodontic treatment that accomplishes these benefits may be limited to a partial fixed appliance localized to one segment of an arch or require a more extensive fixed appliance. Much of this treatment can be accomplished by the interested restorative dentist. Addressing more comprehensive orthodontic problems in patients requiring prosthodontic care is best managed through a restorative dentist and orthodontist team approach to treatment.


Restoration of endodontically treated teeth. Criteria have been presented for the evaluation of and treatment planning for endodontically treated teeth for final restoration. The dentist must consider the advantages and disadvantages of saving teeth according to their eventual role in restoring occlusal function, arch integrity, and esthetics. The prognosis is dependent on successful endodontic therapy, the presence of sound periodontal support, and an acceptable restorative effort. Currently accepted post and core systems and materials have been reviewed.


Restoration of the vertical dimension of occlusion in the severely worn dentition. The guidelines presented in this article for diagnosis and treatment of extreme tooth wear are not meant to be all inclusive. Every patient has unique treatment needs, and all of these needs may not be addressed specifically in this article. We believe, however, that careful adherence to the guidelines presented should facilitate a successful treatment of most if not all patients with moderate or severe tooth wear. The general guidelines for treatment of these patients include the following: 1. A comprehensive examination, including a thorough medical and dental history, orofacial and dental clinical examination, dental radiographs, TMD screening history and examination, impressions and jaw relation records for mounting casts in a semi-adjustable articulator, 2. A diagnostic wax-up and diagnostic occlusal adjustment on additional or duplicated mounted casts, 3. Careful planning and consultation regarding the need for preparatory treatment. Careful integration and sequencing of the different areas of treatment needed to enhance the finished result, 4. Discussion with the patient of the different treatment alternatives and sequences possible for his or her individual case, with presentation of advantages and disadvantages and prognosis for each, 5. Finally, careful execution of the agreed upon treatment plan by the dentist. Although not specifically mentioned, treatment success requires a highly motivated patient and skilled dental laboratory technicians. These "treatment partners" should be included in the planning stages of treatment as early as possible to enhance the possibility of having a successful treatment result.


The clinical use of glass-ionomer cements. The use of glass-ionomer cements in clinical dentistry has expanded greatly over the last decade. Their use in treating early carious or erosion lesions has been investigated widely and established techniques include fissure filling, restoration of erosion lesions without cavity preparation, and the internal or tunnel restoration. Because of their adhesion to moist tooth structure, biologic compatibility, and fluoride release, increasing use also has been made of their anticariogenic properties in treating geriatric patients. Glass-ionomers have proved very successful as dentin substitutes for attaching composites to enamel without involving risk of pulpal damage in the deeper cavity. The deficiencies of glass-ionomer cements are well known, including lack of toughness, early water sensitivity, low abrasion resistance, and porosity, leading to poor surface polish. Solving these problems is formidable because inherently the strength of these cements is related to their water content. The clinician should be aware of these deficiencies and stay within the parameters of the techniques outlined in this article. In particular, clinical success depends on early protection of the cement from hydration or dehydration and the current use of light-cured bonding agents largely has solved this problem. The future probably lies in using laminate techniques in which materials that attach to dentin and form a biologic seal can be covered by tougher and harder enamel veneers, thus mimicking the structure of the tooth. It is possible that future materials will be developed on the lines of these polyelectrolyte cements in which higher molecular weight polymers are used in conjunction with polymers that contain photoinitiators to effect light curing and toughen the matrix. In addition, the possibility of developing laboratory-cured glass-ionomer inlays in which porosity can be reduced and tougher polymers used should be considered.


Esthetic and biomechanical considerations in reconstructions using dental implants. The single-tooth implant-supported restoration can provide an outstanding service to many patients. It requires an understanding of the biomechanical principles involved and attention to the many details involved with the diagnosis and treatment planning for these restorations. The clinician should realize that this restorative approach is contraindicated in many circumstances. As Peter K. Thomas said, "Spend more time planning than doing and doing becomes easier."


Alternative crown systems. Is the metal-ceramic crown always the restoration of choice? The metal-ceramic crown system still is selected the most frequently because of its strength and versatility. The ability to select metals for color or strength for single units or fixed partial dentures gives great flexibility, but when esthetics of the anterior region are a prime concern, the all-ceramic crown is still an excellent choice. Choice of which all-ceramic system to use is dependent on the strength demands, esthetic needs, amount of tooth structure that can be preserved, and laboratory support available. Where good tooth structure remains but some color, contour, or incisal length changes are desired, the porcelain laminate veneer is an outstanding esthetic and restorative choice. When good labial tooth structure remains but lingual structure is inadequate, a partial veneer gold crown can be an excellent esthetic choice. If moderate tooth structure is lost or moderate staining is present, the Dicor crown is a superb choice. In those instances in which heavy staining is present, a foil or core system should be considered to completely block out the background colors. As the occlusal forces become more of a factor, selection of a restorative system will depend more on strength than esthetic demands. The aluminous porcelain jacket crown still offers great strength and esthetics at a reasonable price. When most of the color is on the surface of the teeth, or when there is a high translucency to the teeth, Dicor can provide very esthetic results, and the Dicor Plus crown offers the opportunity to develop intrinsic shading. When greater strength is required, selection of a foil and core system is suggested, as might be a system that provides a stronger core material, like Alceram or Inceram. These stronger core materials will render improved flexural and compressive strengths, but some increases in brightness may occur with the increased alumina content of the cores. The future in ceramic restorative dentistry may be in the computer-generated crown if ways to develop internal coloring and layered building can be developed and cost can be controlled. Ceramic crowns are best limited to the anterior region of the mouth where occlusal forces normally are less than those found in the posterior region. In selected cases, in which there is no evidence of parafunctional habits, and when the dentist and technician are well versed in functional occlusion and have maximum restorative control of the occlusion, posterior ceramic restorations will be successful. It is important to remember in these cases that porcelain is harder than enamel and very strong in compression.(ABSTRACT TRUNCATED AT 400 WORDS)


Fixed prosthodontics in the elderly population. Life expectancy of fixed restorations, failures, and retreatment methods. The restorative needs of older dental patients challenge the ingenuity, anatomic knowledge, artistic skills, occlusal philosophies, and material knowledge of the clinician. Achieving the most secure foundation while simultaneously eliminating imperfections and incorporating a design that promotes good oral hygiene and a natural and attractive appearance are significant contributors to a patient's welfare. The treatment decision regarding fixed prosthodontics for elderly patients requires the balancing of two opposing arguments: 1. In patients who are older, and who are perhaps medically or physically compromised, and, in addition, who may be on a limited budget (or perceived limited budget), it is important to fabricate dental prostheses that are as good as possible to minimize the likelihood that the prosthesis will need to be remade in the future when the patient is likely to be even more compromised financially, medically, or physically, and also to minimize the stress on the patient of accommodating to something that is less than an optimal dental solution. 2. Patients in this age group often anticipate financial strain in the future, perhaps realistically in view of the increasing percent of older adults who are institutionalized (5% of persons 65 years old or older, 20% of persons 80 years old or older). Also, many are reluctant to invest large amounts of money in their teeth when they are already quite elderly and realize they may not live long enough to make the investment "worthwhile." Educating the patient regarding average life expectancy is sometimes helpful, but the experience of many clinical dentists is that many elderly persons either do not believe the numbers, require greater certainty in their "investments," or do not place as high a value on their dental health as they do other aspects of their lives (in a context in which there are more needs than resources to pay for them). Finally, many older adults, contrary to the popular bumper sticker, are trying to preserve as many resources for their children and grandchildren as possible. The final decision should be made with sensitivity to the overall needs of the patient, and with the assistance of a well-informed patient or other responsible party.


Computerized design and manufacturing of esthetic dental restorations. The "high-tech race" in restorative and esthetic dentistry is underway. The Cerec System, which currently leads the race, is reviewed. Other systems, which soon will be available, are discussed briefly. New and innovative technologies are sure to become a significant part of dentistry, both today and in the future. Many traditional methodologies and materials will be replaced by these new developments.


Infection control in fixed prosthodontics. The breadth and depth of our knowledge of infection control continues to increase in dramatic proportions. The literature is already massive and there is nothing to suggest an abatement of this situation. In truth, we can expect the very opposite; an escalation in attention at every level of concern, from the effectiveness of the chemical agents as actually used in the dental environment, to our methods of delivery, as well as the effects on the materials, equipment, and even the personnel in the dental setting. This trend undoubtedly will continue as our understanding of disease processes and the mechanisms of disease transmission increases. This will, in part, directly impact the scope and direction of future study of infection control practices in dentistry.


Diagnostic considerations for the medically complex patient. As advances in medical diagnostic and treatment modalities continue to increase the life expectancy of the population, the likelihood of encountering patients in dental practice with concomitant medical problems will also rise. Thus it will become increasingly important for practicing dentists to take thorough medical histories, recognize signs of systemic disorders, and work closely with their medical colleagues to ensure that safe dental care is rendered to these medically complex patients. Although acutely ill or severely compromised individuals may be best treated in a hospital setting by those with special training, all dental practitioners should possess the diagnostic and communicative skills needed to manage those who are receiving out-patient medical care.


Candida and candidosis. Epidemiology, diagnosis and therapeutic management. Infections caused by Candida species comprise one of the most common oral disease conditions encountered in the practice of dentistry. Gradual changes in population demographics have been accompanied by an increased incidence in candidal and related opportunistic infection rates. Candida albicans and other candidal species traditionally have been recognized as opportunistic pathogens. Recent advances in both the scientific basis for and the clinical significance of candidal organisms, however, have demonstrated these fungi to be distributed widely and to be important contributors to a broad range of mucosal and systemic disease conditions. These factors have allowed for a better understanding of fungal pathogenesis as it affects human oral disease through improvements in clinical and laboratory diagnosis and the therapeutic management of candidosis.


Diagnosis and management of orofacial herpes simplex virus infections. HSV disease remains a significant problem for the dental profession because of its widespread occurrence and ready transmission. Fortunately, available diagnostic techniques are highly sensitive and specific, antiviral therapy is effective in limiting the course of infection, and contemporary infection control procedures adequately safeguard dental personnel and the patient. Unfortunately, there is still a large segment of the population already infected with HSV-1 and the number of immunosuppressed latently infected patients continues to increase. Thus, patients will continue to need the help of the knowledgeable and willing dentist who can diagnose HSV-1 infection, provide effective treatment, and prevent transmission.


Diagnosis and management of autoimmune and idiopathic mucosal diseases. Several autoimmune and idiopathic diseases directly affect the oral mucosa. Current therapeutic management is aimed primarily at the control and prevention of symptoms. It is important for patients to understand the goals of therapeutic management because these diseases often are characterized by periods of remission and exacerbation that require long-term follow-up.


Oral cancer. Etiology, recognition, and management. The cure rate for oral cancers remains dismally low at approximately 50%. The dental profession is, to a large extent, responsible for decreasing the morbidity and mortality of oral cancer even though 50% of the population do not present for routine examination and care. The dental office team must accept the charge of educating all patients concerning the devastating role of tobacco and ethanol in promoting oral cancer, as well as malignancies at other sites. Dental clinicians play a vital role on the oral cancer team. Therefore, they must make themselves well aware of the diverse nature of oral cancer and must have an appropriate triage protocol in place so that lesions will be identified and managed correctly or referred promptly to the correct tertiary health care professionals. Early detection and prompt proper management can make a difference as we await the development of new and better ways of treating oral and oropharyngeal cancers.


Diagnosis and management of acute and chronic oral complications of nonsurgical cancer therapies. This article has reviewed selected oral complications that can develop in the myelosuppressed or head and neck radiation cancer patient. Many of these complications can be prevented by treating diseased oral sites prior to initiation of cancer therapy. Further, cancer treatment often causes changes in oral tissues that require long-term management. The dentist thus can play an important role in the overall care of many cancer patients.


Recognition of worrisome facial conditions by the dentist. We can see that there are a number of conditions that commonly occur on the skin of the face, and that these may be of little or great consequence to our patients. Dentists enjoy an ideal situation for the detection and management or referral of the more worrisome lesions. By paying close attention to the faces of dental patients, asking appropriate questions about the lesions discovered, and following up on the results of advise given to patients, dentists can play an important role as health care advisors concerning dermatologic conditions of the face.


A clinical approach to the diagnosis of facial pain. Following completion of the patient history, physical evaluation, and cranial nerve assessment, the next step should be a thorough dental evaluation with appropriate radiographs to evaluate caries, periodontal disease, and any other hard- or soft-tissue pathology. If indicated, a thorough evaluation of the craniomandibular complex also should be performed. At this point, the clinician should have a general idea as to the cause of the patient's facial pain and the appropriate course of treatment can then be instituted. If the problem is not solely dental in etiology, the diagnosis and management must be coordinated between the dentist and the appropriate medical specialties.


Infection control for dental radiographic procedures in US dental hygiene programmes. Infection control in dental radiographic procedures in US dental hygiene programmes has been investigated by means of a questionnaire and 76% (n = 148) responded. For intra-oral radiography, all but two programmes required the use of gloves during exposure procedures and 94% also required them during processing. Glasses, masks and other protective clothing were required less frequently than gloves. Equipment and working surfaces in the radiographic operatory were generally either disinfected or draped. Equipment and working surfaces in the darkroom were not usually afforded the same degree of diligence in disinfection. Most programmes dried film packets before processing and gave no special treatment to films after processing. Waste products were generally either tied off and marked as a biohazard or sterilized.


Radiological characteristics of lead foils in dental film packets: analysis of components and shielding effect. The radiological characteristics of the lead in five different dental film packets currently on the market in Japan were studied with monochromatic X-rays. Four packets were of a foil type while in the fifth, the lead was incorporated in the vinyl of the film packet. The samples were analysed by polychromatic photon absorptiometry, and the main component found to be lead with tin and/or antimony in smaller amounts. The shielding effect was calculated and, with the exception of the lead vinyl type, all found to exceed the ISO standard 3665. The lead foils attenuated the primary beam by, on average, 77% and 56% at 60 and 90 kVp respectively: in contrast, the reduction with the lead vinyl packet was only 38% and 23%. Using a 7 cm round beam, the lead foils reduced the dose by an average of 15% compared with 30% with a rectangular beam; the average dose reduction with the lead vinyl type was 8% and 15% respectively. These data show that the lead vinyl packet is unsuitable for clinical use and confirm the importance of optimum beam collimation for the reduction of patient risk.


Measurements of tooth length in panoramic radiographs. 1. The use of indicators. The aim of this study was to investigate both the actual and the radiographic tooth lengths of the maxillary first molar and second premolar and the mandibular premolars in panoramic radiographs. The actual length of 64 extracted teeth was measured. Steel balls were then attached to the cusp and apex and the teeth embedded in plastic moulds. Each pair of plaster casts with their set of teeth was radiographed with an Orthopantomograph twice at an interval of 1 month. The actual and the radiographic tooth length was measured twice by one observer. The mean tooth length of the molar was shorter than that of the premolars. The mean difference between the repeated measurements of the actual tooth length was small and ranged between 0.47 and 1.16% of the tooth length. The mean difference between repeated measurements of the radiographic tooth length was also small, with a method error of 0.13-0.21 mm. The vertical magnification in panoramic radiography was lower for mandibular premolars (13-15%) than for the maxillary second premolar and first molar (17-28%). The palatal root of the maxillary first molar had the highest vertical magnification (28%). Following the second set of radiographs, the mean difference between the measurements was small, except for the palatal root of the maxillary first molar (P < 0.001). Radiographic measurements of this root should therefore be used with caution. The results for the other roots examined indicate that these could be measured with high reproducibility.


Measurements of tooth length in panoramic radiographs. 2: Observer performance. Observer performance in tooth-length measurements in panoramic radiography has been examined. Sixty-four teeth, evenly distributed between maxillary first molars, second premolars and mandibular first and second premolars, were fixed in plastic moulds. Each cast was radiographed with an Orthopantomograph, twice with steel balls indicating the cusps and apices of the teeth and once without them. One observer measured the radiographic tooth length twice in both radiographs with indicators in order to estimate the true radiographic tooth length and the repositioning error, and twice in the radiographs without indicators. Seven other observers measured the tooth length on the radiographs without indicators, twice applying their own criteria and twice using defined criteria. The accuracy of the tooth-length measurements was calculated by comparing the true radiographic tooth length with the measurements of the seven observers. The intra-observer variation was defined as the difference between two measurements on the same radiograph. The accuracy and the precision of the tooth-length measurements were highly influenced by the observer performance. The mean radiographic tooth length of the seven observers was closer to the true radiographic tooth length when the observers applied the defined criteria. The inter- and intra-observer variation was higher for the measurements of the maxillary teeth (0.3-1.9 mm) compared with the mandibular teeth (0.3-0.9 mm) for most observers. The highest intra-observer variation was found for the palatal root of the maxillary first molar. The intra-observer variation of four observers decreased somewhat when the defined criteria were used; for the other three observers, however, the variation increased.(ABSTRACT TRUNCATED AT 250 WORDS)


Radiological survey of the cervical spine in cleft lip and palate. Cleft lip and palate is known to be associated with a number of other skeletal anomalies. The purpose of this study was to investigate the prevalence of possible malformations of the cervical spine and their relationship to velopharyngeal incompetence. The lateral cephalometric radiographs of 30 patients aged between 14 and 27 years of age with cleft lip and palate were compared with these of a control group, who had been involved in cycle accidents. The radiographs were assessed for morphological anomalies of the first and second cervical vertebrate and, in addition, longitudinal and angular measurements performed. Speech was assessed by electromagnetic articulography. A greater number of cervical spine anomalies were found in patients with cleft lip and palate and these were also associated with significantly (P < 0.05) greater osseous-nasopharyngeal depth.


Comparison of photodensitometric with high-resolution digital analysis of bone density from serial dental radiographs. Photodensitometry is known to provide high spatial resolution and continuous measurement of optical density for the analysis of dental radiographs, whereas digitization allows powerful image manipulations but, when using conventional video cameras, gives less spatial resolution and fewer grey levels. The aim of this study was therefore to develop a technique of high-resolution digital analysis for the measurement of bone density following the same principles as those of photodensitometry and based upon the use of a CCD Scanner Camera which provides up to 4096 grey levels and a spatial resolution of 4096 x 4096 pixels. Twenty-four zones were analysed with both techniques in five serial dental radiographs taken before and after periodontal therapy in eight patients. Statistical comparison of the results obtained by digital analysis and photodensitometry shows that the two techniques have the same accuracy.


Rosette formation of impacted molar teeth in mucopolysaccharidoses and related disorders. The radiographic features of the jaws in the mucopolysaccharidoses and related disorders (MPS) have been reviewed and three further cases are reported here, with particular reference to a novel dental anomaly, not previously described in detail, in two of them. The dental changes appear to be fully developed by the third decade and are characterized by bilateral multiple impacted molar teeth, which conglomerate in a single follicle to form a characteristic rosette of teeth. Rosetting was present only in relatively mature cases of MPS. However, it was also seen in the fourth patient, where we could not detect any other abnormal clinical or radiographic features. We therefore propose that since multiple rosetting of molar teeth can also occur in an isolated form, it is only suggestive of MPS.


Effects of niobium filtration and constant potential on image quality in dental radiography. 2. Objective assessment. The effects of niobium filtration and constant potential on image quality were explored by asking observers to identify numbers of circular areas of small density differences in zones of high and low density. Successful identification was related negatively to half-value layer. This relationship was particularly strong in the case of self-rectified units without additional niobium filtration and the constant potential units (r2 = 0.994, P < 0.0005). Constant potential had no effect other than in relation to half-value layer. Additional niobium filtration detracted from successful identification, but slightly less than would be predicted by the half-value layer. Whether this difference is significant or relevant has not been established. The findings of this study, in conjunction with our previous investigations, have failed to demonstrate any clear indications for preferring constant potential supply over self-rectification or for using niobium as an additional filter material. Half-value layer has been shown to be a reliable indicator of the effects of beam quality on emulsion speed, attenuation in water, and image quality. It appears that the methods employed to change the beam quality have no specific effects.


Adenomatoid odontogenic tumour. Report of an unusual lesion in the posterior maxilla. The adenomatoid odontogenic tumour most commonly presents as a 1.5-3 cm radiolucency in the anterior maxilla, and often associated with an unerupted tooth. It is very unusual for these tumours to occur behind the premolar region and the few reports of much bigger lesions have been in black African patients. This article describes an unusually large example of this tumour associated with an unerupted maxillary third molar tooth in a white female.


Comprehensive oral X-ray diagnosis: Scanora multimodal radiography. A preliminary description. Scanora (Soredex, Orion Corporation, Helsinki, Finland) is a multimodal radiography system which utilizes the principles of narrow beam radiography and spiral tomography. The system includes an integrated multifunction X-ray unit, a coordinate system for object localization and a wide selection of dental and maxillofacial imaging problems. All imaging procedures are computer controlled and executed automatically. Clinical experience and preliminary results show that the multimodal imaging system has great potential in the detection of pathological conditions of the maxillofacial region.


The value of magnetic resonance imaging in the assessment of a sublingual epidermoid cyst. A case is presented demonstrating the value of magnetic resonance imaging (MRI) in the assessment of a midline sublingual epidermoid cyst in a 22-year-old female. The advantages of MRI compared with CT in the evaluation of soft-tissue lesions in the sublingual space are discussed.


Digital subtraction radiography in artificial recurrent caries detection. The diagnostic accuracy of digital subtraction radiography in detection of artificial recurrent caries lesions was assessed in this project. The use of digital subtraction radiography has been shown to markedly increase the accuracy of the detection of destruction in the periodontal bone, but the method has not been evaluated in secondary caries detection. Defects of three different sizes, simulating recurrent caries, were sequentially prepared in the interproximal cavity preparation margins of 28 teeth. Two composite restorative materials with different radiographic densities were used as posterior restorations, and a radiograph was obtained of each defect size and restorative material. The radiographs were digitized and subtracted from the reference images, and the conventional radiographs and the subtraction images were evaluated by seven observers. The data were analysed with ROC statistics. Subtraction radiography was found to be superior to conventional radiography in recurrent caries detection, mainly by reducing the false-positive diagnoses. The radiopacity of the restorative material had a significant effect on accuracy with conventional but not with subtraction radiography.