P0467THE DIRECT USE OF ORAL ANTI-COAGULANTS IN MEMBRANOUS NEPHROPATHY

Background and Aims

Barts Health has a dedicated membranous nephropathy (MN) service with 15-20 incident cases per year. Nephrotic syndrome secondary to MN in particular is associated with arterial and venous thrombosis. There is little evidence to guide optimum pharmacological prophylaxis. In those considered high risk, options include warfarin, heparin or aspirin. The advent of direct oral anti-coagulants (DOACs) offers an alternative, though evidence of efficacy is isolated to case studies.

All patients with an albumin <25g/L are offered anticoagulation. We describe our use of DOACs in a large single centre MN cohort.

Method

Retrospective data MN patients between 2015-2019 was analysed. This included: demographics; frequency, type and timing of thromboembolic and bleeding events; biochemical data at initiation and cessation of agent.

Results

Total number of patients: 26

DOAC treatment courses: 30

Exposure to drug (patient days): 9899

Malignancy was excluded in all cases, with the exception of 1 case of MN secondary to cancer.

There were 3 thromboembolic events in 3 patients; all events occurred on rivaroxaban and in PLA2Rab positive MN.

Thrombotic events were all arterial, with no venous events, 2 cerebral artery infarcts and 1 lower limb arterial thrombosis. These patient’s mean initial presentation PLA2Rab titres were 164 Kunits/L (75-248) and all were nephrotic at the time of the thromboembolic event. Events were 29, 128 and 340 days post DOAC initiation. 2 of these patients had a venous thrombosis prior to DOAC initiation. Event rate: 0.11 per patient year

Safety data also demonstrated 3 bleeds in this patient cohort - all were minor as per ISTH criteria. 2 epistaxes and 1 associated with rectal prolapse, all without a haemoglobin drop.

Conclusion

Our experience is that DOACs are safe and effective in patients with MN and offer a viable anti-coagulant alternative.

The effect of hand-arm vibration syndrome on quality of life

BACKGROUND

It is important to determine how hand-arm vibration syndrome (HAVS), a common occupational condition, affects quality of life (QOL).

AIMS

To measure the physical (SF12-P) and mental (SF12-M) components of QOL in workers with HAVS, using the SF12 questionnaire, and to determine the effect of the vascular, sensorineural and musculoskeletal components of HAVS on QOL.

METHODS

Subjects were recruited consecutively from workers with HAVS attending an occupational medicine clinic. They were assessed to determine the Stockholm vascular and sensorineural scale stages as well as an upper extremity pain score, measured by the Borg scale, as an indication of musculoskeletal problems associated with the use of vibrating tools. The SF12-P and SF12-M were both compared with Canadian population normal values after adjusting for age and sex. Multiple linear regression was used to determine the effect of the various HAVS components on SF12-P and SF12-M as well as the effects of age and carpal tunnel syndrome.

RESULTS

One hundred and forty-one subjects were recruited and 139 (99%) agreed to participate, including 134 men and 5 women. The SF12-P and SF12-M scores were significantly below the Canadian population mean values (P < 0.001), indicating lower QOL. In the multiple regression analysis, the predictor with the largest partial R (2) value for both the SF12-P and SF12-M was the upper extremity pain score.

CONCLUSIONS

Both the physical and the mental QOL in workers with HAVS were below Canadian population normal values and subjects' upper extremity pain score had the greatest effect on their QOL.

DASH work module in workers with hand-arm vibration syndrome

BACKGROUND

The Disabilities of the Arm, Shoulder and Hand work module (DASH-W) questionnaire has not previously been described in relation to hand-arm vibration syndrome (HAVS).

AIMS

To measure work-related disability in workers with HAVS using the DASH-W questionnaire and to determine how the various components of HAVS affect the DASH-W score.

METHODS

Workers with HAVS from a variety of industries were assessed over a 2-year period at the occupational health clinic, St Michael's Hospital, Toronto. Subjects completed the DASH-W questionnaire and were assessed by an occupational physician to determine their Stockholm sensorineural and vascular stages and upper extremity pain score measured by the Borg scale, as an indication of musculoskeletal problems associated with HAVS. The average DASH-W score was compared with the average value for the US population. Multiple linear regression was used to determine the contribution of the various components of HAVS to the DASH-W score.

RESULTS

There were 139 (134 men and 5 women) participants. The subjects with HAVS had a mean DASH-W score of 54.7 (95% CI: 50.3-59.1), which was considerably higher than the average for the US population (P < 0.001). Statistically significant HAVS variables in the multiple linear regression included the Stockholm sensorineural stage (P < 0.05) and the upper extremity pain score (P < 0.001) with the pain score having the highest partial R (2) value.

CONCLUSIONS

Workers with HAVS reported significant upper extremity work-related disability as measured by the DASH-W questionnaire, and the upper extremity pain score made the largest contribution to the DASH-W scores in these subjects.

Do u smoke after txt? Results of a randomised trial of smoking cessation using mobile phone text messaging

OBJECTIVES

To determine the effectiveness of a mobile phone text messaging smoking cessation programme.

DESIGN

Randomised controlled trial

SETTING

New Zealand

PARTICIPANTS

1705 smokers from throughout New Zealand who wanted to quit, were aged over 15 years, and owned a mobile phone were randomised to an intervention group that received regular, personalised text messages providing smoking cessation advice, support, and distraction, or to a control group. All participants received a free month of text messaging; starting for the intervention group on their quit day to assist with quitting, and starting for the control group at six months to encourage follow up. Follow up data were available for 1624 (95%) at six weeks and 1265 (74%) at six months.

MAIN OUTCOME MEASURES

The main trial outcome was current non-smoking (that is, not smoking in the past week) six weeks after randomisation. Secondary outcomes included current non-smoking at 12 and 26 weeks.

RESULTS

More participants had quit at six weeks in the intervention compared to the control group: 239 (28%) v 109 (13%), relative risk 2.20 (95% confidence interval 1.79 to 2.70), p < 0.0001. This treatment effect was consistent across subgroups defined by age, sex, income level, or geographic location (p homogeneity > 0.2). The relative risk estimates were similar in sensitivity analyses adjusting for missing data and salivary cotinine verification tests. Reported quit rates remained high at six months, but there was some uncertainty about between group differences because of incomplete follow up.

CONCLUSIONS

This programme offers potential for a new way to help young smokers to quit, being affordable, personalised, age appropriate, and not location dependent. Future research should test these findings in different settings, and provide further assessment of long term quit rates.

Rounded atelectasis in an asbestos exposed worker

The case history is presented of a 51-year-old electrical power worker with a history of asbestos exposure presenting with rounded atelectasis. No other radiological markers of asbestos exposure were present. A documented history of asbestos exposure and exclusion of other causes of rounded atelectasis led to the diagnosis of asbestos related rounded atelectasis. It is important to understand that rounded atelectasis can be an isolated finding due to asbestos exposure. This facilitates investigation of lung masses of unknown etiology and initiation of appropriate follow up of patients at risk for future development of more debilitating asbestos related pathology.

Hand-arm vibration syndrome from exposure to high-pressure hoses

Hand-arm vibration syndrome has been reported in the literature to occur following exposure to vibration from the use of many tools, but to date there have been no case reports of its occurrence in workers who have used high-pressure hoses, alone or with other tools. To remedy this, the case histories of nine subjects (two without mixed exposure) examined in the UK and Canada are presented, together with their severity classified according to the Stockholm scales. Attention is drawn to the need to use multiple diagnostic tests to establish the diagnosis and the need to implement vibration isolation and damping methodologies, as and when feasible, with respect to hose nozzles in order to minimize the hazard. The ultimate goal for tool manufacturers, hygienists and engineers should be to reduce workplace vibration levels to meet national and international guidelines and legislation, including UK Health & Safety Executive guidelines and European Economic Community directives. The respective risk levels are presented, together with vibration measurements on hoses used by some of the cases.

Modification and inhibition of vancomycin group antibiotics by formaldehyde and acetaldehyde

It is shown that several vancomycin group antibiotics (vancomycin, eremomycin, and avoparcin) undergo spontaneous chemical modifications when kept at room temperature at neutral pH in aqueous solutions containing traces of formaldehyde or acetaldehyde. This chemical modification predominantly results in a mass increase of 12 Da in the reaction with formaldehyde and 26 Da in the case of acetaldehyde. By using tandem mass spectrometry the modification can unambiguously be identified as originating from the formation of a ring-closed 4-imidazolidinone moiety at the N-terminus of the glycopeptide antibiotics, that is, near the receptor binding pocket of the glycopeptide antibiotics. Bioaffinity mass spectrometry shows that this ring-closure results in a dramatically decreased affinity for the peptidoglycan-mimicking D-alanyl-D-alanine receptor. Additionally, in vitro inhibition measurements on two different strains of bacteria have revealed that the modified antibiotics display reduced antibacterial activity. The ring-closure is also shown to have a dissociative effect on the dimerization of the vancomycin-analogue eremomycin. The spontaneous reaction of vancomycin with formaldehyde or acetaldehyde may have implications not only for the clinical use of this class of antibiotics, but also for the effectiveness of these antibiotics when they are used in chiral separation chromatography or capillary electrophoresis.

Palladium-Catalyzed Tandem Reactions To Form 1-Vinyl-1H-isochromene Derivatives1

The palladium-catalyzed reaction of pinacolone with tert-butyldimethyl(3-(2-bromophenyl)allyloxy)silane results in direct formation of 1-vinyl-3-tert-butyl-1H-isochromene. This is the result of a ketone arylation followed by an intramolecular cyclization of the enolate with the allylic system. The use of a lithium diamide base appears to be essential for success. The tert-butyldimethylsilyl protecting group is also an essential choice as it furnishes the appropriate reactivity to promote allylic substitution after the aryl coupling process. The use of more effective leaving groups, such as acetate, results in reaction of the allylic group, and no aryl coupling is observed. Through the appropriate selection of phosphine ligand and solvent, either the cyclized isochromene product or the noncyclized intermediate may be formed selectively. A short combinatorial study of the scope and limitations of the reaction, involving 24 ketones, is described.

Preliminary results of a randomized controlled trial of prophylactic shock wave lithotripsy for small asymptomatic renal calyceal stones

OBJECTIVE

To report a prospective, randomized study to determine whether prophylactic extracorporeal shockwave lithotripsy (ESWL) is justified as a treatment for small, asymptomatic calyceal stones.

PATIENTS AND METHODS

The study included 228 patients with small (< 15 mm total diameter) asymptomatic calyceal stones; 113 patients were randomized to undergo ESWL and 115 to the control group who were kept under observation. Outcome measurements included the stone-free rate, requirement for additional treatment, symptoms, quality of life and renal function.

RESULTS

In all, 200 patients had at least one annual follow-up; all outcome measurements reported were those at the most recent follow-up (mean 2.2 years, range 1-5). In the ESWL group 28 patients (28%) were stone-free, compared with 16 (17%) in the observation group (odds ratio 1.95, 95% confidence interval, CI, 0.97-3.89, P = 0.06). Additional treatment in the form of analgesics, antibiotics, ESWL, stent insertion and ureteroscopy, was required in 21 (21%) patients in the observation group and 15 (15%) in the ESWL group (odds ratio 0.66, 95% CI 0.32-1.37, P = 0.27). Ten patients in the observation group required invasive procedures, vs none in the ESWL group. There was no evidence of differences in the symptoms, quality of life or renal function tests between the arms of the trial at the final follow-up.

CONCLUSIONS

Prophylactic ESWL for small asymptomatic renal calyceal stones does not appear to offer any advantage to patients in terms of stone-free rate, quality of life, renal function, symptoms or hospital admissions. However, a policy of observation is associated with a greater risk of requiring more invasive procedures. A longer follow-up is required to assess the validity of these preliminary findings.

Chemistry and clinical biology of the bryostatins

Bryostatins are a class of antineoplastic compounds isolated from the bryozoans Bugula neritina. A wide range of scientific research is currently underway, studying different aspects of the bryostatins. In this review we try to summarize the latest findings, including all the topics involved, from marine biology to medicinal chemistry.

Manipulation of the phenotype of immortalised rat hepatocytes by different culture configurations and by dimethyl sulphoxide

The liver-specific phenotype of immortalised rat hepatocytes is not irretrievably lost as they age in culture but can be manipulated by modifying the culture environment. Testosterone metabolism was used to investigate the profile of cytochrome P450 isoenzymes present in two immortalised cell lines, P9 and LQC, and in primary cultures of rat hepatocytes, cultured on collagen films, gels and double gel cultures (sandwich configuration). The extent of testosterone metabolism, and the range of metabolites produced, was increased in immortalised cells by the presence of collagen as a substratum film or gel but survival was poorer and the range of metabolites was reduced in sandwich culture. In contrast, testosterone metabolism was retained in primary hepatocytes in sandwich cultures at a higher level than in collagen film or gel cultures. Expression of alpha class glutathione-S-transferases (GSTs) increased and that of GSTP1 decreased (changes which indicate a recovery of normal liver GST phenotype) when the medium of immortalised cell cultures was supplemented with dimethyl sulphoxide (DMSO). DMSO also improved ethoxyresorufin O-deethylation (EROD) and testosterone metabolism in immortalised cells. It also markedly inhibited proliferation, DNA, RNA and protein synthesis. Maximal testosterone metabolism was observed in immortalised cells cultured on collagen gels in the presence of 1% (v/v) DMSO. Development of a protocol for treating immortalised liver cells cultured on collagen gels with DMSO to switch between proliferation and differentiation may provide a convenient system expressing the xenobiotic metabolising enzymes required for in vitro toxicity testing.

Early observations of the effect of extracorporeal shockwave lithotripsy on blood pressure: a prospective randomized control clinical trial

OBJECTIVE

To determine, in a randomized controlled clinical trial, the effect of extracorporeal shock wave lithotripsy (ESWL) on blood pressure.

PATIENTS AND METHODS

The trial included 228 patients with small (< 15 mm) asymptomatic calyceal stones who were randomised to undergo ESWL (113 patients) or to an untreated (observed) control group (115 patients). Blood pressure was recorded at randomization using a standardized protocol. Patients undergoing ESWL received a mean (SD) of 5281 (3462) shocks over a mean of 1.75 sessions on one of two lithotripters. Patients were then followed annually, assessing blood pressure and changes in medication. Data were analysed on an intention-to-treat basis.

RESULTS

At randomization, 43% of patients in the control group and 53% in the ESWL group were hypertensive. Of the 228 randomized, 200 patients completed at least one annual follow-up, of whom 192 (93 in the control and 99 in the ESWL group) had their blood pressure recorded. The mean follow-up was 2.2 years; 35 (37%) patients in the control and 46 (46%) in the ESWL group were hypertensive (P = 0.19). Seven (7%) patients in the control group and 11 (11%) in the ESWL group were newly diagnosed to be hypertensive (P = 0.35).

CONCLUSIONS

In this randomized controlled clinical trial there was no evidence that ESWL causes changes in blood pressure.

Comparative genomic hybridization analysis of hepatoblastomas

Prior cytogenetic analyses of hepatoblastomas have shown the most common recurring abnormalities to be trisomy for chromosomes 2 and 20, and a recurrent translocation involving chromosomes 1 and 4 identified in a minority of cases. Four cases have shown double minute chromosomes, which provide cytogenetic evidence for gene amplification, although no particular genes or genetic regions have been shown to be amplified. To further investigate the cytogenetic changes involved in the pathogenesis and progression of hepatoblastoma, this study analyzes 10 tumors by comparative genomic hybridization. Regions of relative gain or loss were found in nine tumors. The most common recurrent abnormalities were gain of the long arm of chromosome 1 (six tumors), gain of chromosomes 2 (seven tumors), 17 (four tumors), and 20 (three tumors), and loss of chromosomes 4 and 11 (two tumors each). Four cases showed restricted regions of high-level gain at 1q32 or 2q24, regions that have previously been reported to be amplified in other tumors, but not in hepatoblastomas. A specific amplified gene has yet to be identified at these loci, although candidate genes have been proposed and may offer targets for future studies. Genes Chromosomes Cancer 27:196-201, 2000.

Neural innervation of the newborn exstrophic bladder: an immunohistochemical study

PURPOSE

Continence in bladder exstrophy is not always easy to attain. Some patients have a small noncontractile bladder while in others an adequate capacity bladder may not contract normally. Innervation of the detrusor determines its ability to contract. The exstrophic bladder during organogenesis does not store urine. Therefore, its requirements for contraction are limited and its innervation would potentially reflect this difference in function. The availability of specific immunostains allows better differentiation of the neural elements in tissue specimens. Our study focuses on myelinated nerves innervating the newborn exstrophic detrusor.

MATERIALS AND METHODS

Biopsies were obtained from the anterior wall of 10 newborn exstrophic bladders at the time of initial closure and compared to 10 newborn controls. Patient age at bladder closure ranged from 1 to 90 days (mean 22). Specimens were formalin fixed and paraffin embedded. Then 4 micro. thick sections were stained with S100, an immunostain that stains neural crest elements including Schwann's elements (myelinated nerve fibers). The entire tissue section was examined. Microscopic fields were sequentially examined with a morphometric system comprising a microscope, video camera and personal computer with a video frame grabber. The output image was displayed on a second monitor and the nerves in each field and numbers of fields in each section were counted. To be considered, fields had to have greater than 75% tissue coverage. The average number of nerves per field was compared between the exstrophic bladders and normal controls.

RESULTS

The average number of myelinated nerves per field in the newborn exstrophic bladders (0.13 per field) was significantly reduced compared to normal controls (1.25 per field) and statistically significant (p<0.001). This reduction in nerve fibers appeared to be due to lack of smaller fibers with preservation of larger fibers. There was no difference in innervation in cases closed at birth compared to those closed after month 1 of life.

CONCLUSIONS

The newborn exstrophic bladder has fewer myelinated nerve fibers than normal controls primarily due to reduction in the smaller fibers which may represent a maturational delay in the development of the exstrophic bladder. Another possible explanation may be degeneration of the fibers due to lack of bladder contraction but no indication of nerve degeneration was evident in our study. Followup studies of patients at various stages of reconstruction will determine the evolution of neural innervation in the exstrophic bladder.

Progressive loss of IL-2-expandable HIV-1-specific cytotoxic T lymphocytes during asymptomatic HIV infection

In HIV-1 infection, circulating HIV-1-specific cytotoxic T lymphocytes (CTL) exist in different states of activation, including activated cytotoxic cells and memory cells. We report that a subpopulation of HIV-1-specific CTL is capable of clonal expansion upon culture with IL-2 without exogenous antigen. The IL-2-expandable HIV-1-specific CTL precursor frequency was reduced in patients with advancing infection, although HIV-1-specific memory CTL could still be detected by stimulation in vitro with allele-specific HIV-1 peptide. Longitudinal analysis during advancing infection showed a progressive decline in the IL-2-expandable HIV-1-specific CTL precursor (CTLp) frequency without a decline in Epstein-Barr virus (EBV)-specific or allo-specific CTLp frequencies. To address mechanisms that may contribute to the decline in the IL-2-expandable HIV-specific CTL response, the requirements for in vitro generation of HIV-1-specific and EBV-specific effector CTL were examined. In the absence of exogenous IL-2 in limiting dilution, generation of EBV-specific CD8+ effector CTL was dependent upon help from CD4+ cells. CD4+ help for EBV-specific CD8+ CTL was observed in asymptomatic HIV infection but not in advanced infection. In the presence of exogenous IL-2, CD4+ cells could also provide help for the optimal generation of HIV-1 peptide-specific CD8+ CTL, because in vitro depletion of CD4+ cells prior to culture using stimulation with an MHC class I-restricted HIV-1 peptide reduced the peptide-specific CD8+ CTL response. We conclude that there is a decline in the IL-2-expandable HIV-1-specific CTL response during advancing infection. There are a number of possible mechanisms for this decline, including a reduction in CD4+ T cell help for in vivo antigen-activated CD8+ T cells.

Impact vibration and hand-arm vibration syndrome

The case histories of ten workers with Hand-Arm Vibration Syndrome (HAVS) indicate that their predominant vibration exposure was to impact vibration. This association, recognized previously in pedestal grinders and in multiple hand tool users, should now be identified in spot welders and press operators. This will have important implications for compensation claimants as well as prevention development.

Serum pooling lowers cholesterol recovery

Matrix effects hinder the transferability of accuracy for cholesterol. A general assumption is that pooled and individual samples yield similar results. We tested the hypothesis that serum-pooling affects the recovery for cholesterol. We pooled 100 serum samples, determining cholesterol of pool and of the individual samples with Hitachi 717 and 914. Over twenty days, we daily determined cholesterol of individual and pooled samples, using a Hitachi 736 and 747 analyzers. For the hundred-sample pool, the pool was 1.1 to 1.5% lower than the individual samples. With the daily pool study, the ratio of 747 to 736 was 1.7% lower for the pooled compared with the individual samples. Therefore, pooling of serum samples causes a decreased recovery, averaging from 1.1-1.7%, and representing 37-57% of the allowable bias for cholesterol (< 3%), and it is thereby significant.

A gene for autosomal dominant nonsyndromic hereditary hearing impairment maps to 4p16.3

Mapping genes for nonsyndromic hereditary hearing impairment may lead to identification of genes that are essential for the development and preservation of hearing. We studied a family with autosomal dominant, progressive, low frequency sensorineural hearing loss. Linkage analysis employing microsatellite polymorphic markers revealed a fully linked marker (D4S126) at 4p16.3, a gene-rich region containing IT15, the gene for Huntington's disease (HD). For D4S126, the logarithm-of-odds (lod) score was 3.64 at theta = 0, and the overall maximum lod score was 5.05 at theta = 0.05 for D4S412. Analysis of recombinant individuals maps the disease gene to a 1.7 million base pair (Mb) region between D4S412 and D4S432. Genes for two types of mutant mice with abnormal cochleovestibular function, tilted (tlt) and Bronx waltzer (bv), have been mapped to the syntenic region of human 4p16.3 on mouse chromosome 5. Further studies with the goals of cloning a gene for autosomal nonsyndromic hearing impairment and identifying the murine homologue may explain the role of this gene in the development and function of the cochlea.

Highly attenuated HTLV type Ienv poxvirus vaccines induce protection against a cell-associated HTLV type I challenge in rabbits

The entire envelope protein of the human T cell leukemia/lymphoma virus type I (HTLV-I)1711, obtained from the DNA of a West African healthy HTLV-I-infected patient, was expressed in the highly attenuated poxvirus vaccine vectors ALVAC and NYVAC. These live recombinant vaccine candidates were used to immunize New Zealand White rabbits. Immunization regimens included inoculation of the poxvirus recombinant alone as well as prime/boost protocols using gp63 HTLV-I envelope precursor protein in Alum as the subunit boost. All animals were exposed to an HTLV-I cell-associated challenge (5 x 10(4) cells) from a primary culture of the HTLV-IBOU isolate. The results indicated that two inoculations of the ALVAC-based HTLV-Ienv vaccine candidate protected animals against viral challenge 5 months following the last immunization. However, a combination protocol with ALVAC-env and two additional boosts of gp63 surprisingly failed to confer protection, suggesting that administration of the subunit preparation might be deleterious. Further, in the case of the NYVAC HTLV-Ienv recombinant, protection was afforded as early as 2 months following the first immunization. Last, all the protected animals in the NYVAC and ALVAC trials were challenged 5 months following the initial challenge exposure with 5 ml of blood from an HTLV-IBOU-infected animal, and subsequently became infected. Protection conferred by the attenuated HTLV-Ienv recombinant poxvirus vaccine in the rabbit model might be instrumental for optimizing the immunogenicity of poxvirus-based vaccine candidates against human immunodeficiency virus (HIV), particularly because of the need to enhance protection against cell-to-cell transmission.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative urinary cyclic AMP monitoring in primary hyperparathyroidism

OBJECTIVE

This study examined the utility of intraoperative urinary cyclic 3'5' adenosine monophosphate (UcAMP), an indicator of parathyroid (PTH) hormone end-organ activity, as a "biochemical frozen section," signaling the real-time resolution of PTH hyperactivity during surgery for primary hyperparathyroidism.

SUMMARY BACKGROUND DATA

The unsuccessful initial neck exploration for primary hyperparathyroidism, leaving the patient with persistent hyperfunctioning parathyroid tissue, results in part from the surgeon's inability intraoperatively to correlate a gland's gross appearance and size estimation with physiologic function. Preoperative imaging, intraoperative imaging, and intraoperative histologic/cytologic surveillance have not resolved this dilemma.

METHODS

Twenty-seven patients underwent a prospective intraoperative UcAMP monitoring protocol. The patients all had a clinical diagnosis of primary hyperparathyroidism and an average preoperative serum calcium of 12.0 +/- 0.3 mg/dl. UcAMP was assayed intraoperatively using 20-minute nonequilibrium radioimmunoassay providing real-time feedback to the operating team.

RESULTS

All patients had an elevated UcAMP confirming PTh hyperactivity at the beginning of the procedure. One patient, subsequently found to have an supernumerary ectopic adenoma, had four normal glands identified intraoperatively, and his intraoperative UcAMP values corroborated persistent hyperparathyroidism, the UcAMP of the remaining 26 patients decreased from 7.0 +/- 1.1 to 2.7 +/- 0.7 nm.dl GF (p < .00005) after complete adenoma excision, and they remain normocalcemic. The protocol provided useful and relevant information to the operating team, and aided in surgical decision-making, in 10 of the 27 cases (37%).

CONCLUSION

Intraoperative biochemical surveillance with ucAMP monitoring reliably signals resolution of PTH hyperfunction. It is a useful adjunct to the surgeon's skill, judgment, and experience in parathyroid surgery.

Reconstitution of Escherichia coli photolyase with flavins and flavin analogues

Escherichia coli DNA photolyase contains two chromophore cofactors, 1,5-dihydroflavin adenine dinucleotide (FADH2) and (5,10-methenyltetrahydrofolyl)polyglutamate (5,10-MTHF). A procedure was developed for reversible resolution of apophotolyase and its chromophores. To investigate the structures important for the binding of FAD to apophotolyase and of photolyase to DNA, reconstitution experiments with FAD, FMN, riboflavin, 1-deazaFAD, 5-deazaFAD, and F420 were attempted. Only FAD and 5-deazaFAD showed high-affinity binding to apophotolyase. The apoenzyme had no affinity to DNA but did regain its specific binding to thymine dimer containing DNA upon binding stoichiometrically to FAD or 5-deazaFAD. Successful reduction of enzyme-bound FAD with dithionite resulted in complete recovery of photocatalytic activity.

Aging and cholinergic responses in bovine trachealis muscle

1. The relative potencies of muscarinic agonists on bovine tracheal smooth muscle were unchanged as a consequence of aging and were carbachol greater than oxotremorine greater than muscarine greater than pilocarpine greater than McNeil A-343. 2. During aging, the potencies of carbachol, oxotremorine, McNeil A-343 and pilocarpine, but not muscarine, were reduced. 3. Maximal induced tensions to all the agents studied were reduced as a consequence of age. 4. Irreversible antagonism with benzilylcholine mustard showed that agonist efficacy was significantly reduced during aging. 5. Estimated receptor occupancy at the EC50 was significantly greater in tracheal tissues from the mature versus immature cows for every agonist studied. 6. The dissociation constants for full agonists (carbachol, oxotremorine and methacholine) were decreased with maturation while the converse was observed with partial agonists (McNeil A-343, pilocarpine). 7. We conclude that there are significant changes in the properties and coupling of muscarinic receptors during aging. These changes may contribute to the reduced airway reactivity seen in vivo.

Passive body heating and sleep: influence of proximity to sleep

Previous studies have found enhanced delta sleep following body heating. This study assessed the influence of body heating as a function of its proximity to sleep. Electroencephalogram (EEG) sleep patterns were compared following body heating (1 h immersion in water at 41 degrees C) at each of four times of day: morning (MO), afternoon (AF), early evening (EE), and late evening (LE), ending just prior to sleep. A delta filter/integrator system provided objective measures of delta content. Relative to baseline nights, whole-night delta sleep was increased by the two evening heating sessions only, particularly LE heating. Following LE, the increased delta occurred primarily in the first sleep cycle, whereas EE heating elicited increased delta distributed across the later sleep cycles (cycles 2-4). Effects on manually staged indices of slow wave sleep (SWS) were confined to increases in Stage 4 in the first sleep cycle following LE heating. Heating just prior to sleep also resulted in a substantial reduction in the duration of the first rapid eye movement sleep period. Sleep onset time was reduced by heating, particularly EE heating. The results indicate that body heating induces temporary changes that affect sleep propensity and both the quantity and temporal distribution of delta activity in the sleep EEG.

The response of kidney to ionizing radiation combined with hyperthermia induced by ultrasound

Mouse kidneys were made hyperthermic (42.5 degrees C for 30 min) one hour before, during, or one hour after local irradiation to determine the effect of hyperthermia on radiation damage. An ultrasound beam was used to induce hyperthermia. The urinary concentrations of total protein and albumin were used as criteria of kidney injury. Hyperthermia alone did not induce proteinuria. Radiation alone produced proteinuria that was not correlated with dose. Hyperthermia induced during or after irradiation resulted in a thermal enhancement factor of 1.29 +/- .33. Hyperthermia induced one hour before irradiation resulted in a thermal enhancement factor of 0.88 +/- .05, indicating a radioprotective effect. To the authors' knowledge, this is the first time such an effect has been shown.

Leukocyte and bacterial interrelationships in experimental meningitis

Eighty-one rabbits were inoculated with known concentrations of type III pneumococci by cisternal puncture and then started on antibiotic therapy the following day. Aliquots of cerebrospinal fluid were sampled at regular intervals both before and after therapy and then analyzed for bacterial titer and leukocyte count. These data were used to examine the interrelationships of inoculum size, leukocyte count, and bacterial titer to each other and their effects both univariately and multivariately on outcome. Inoculum size was the most important single variable affecting outcome, followed in order by the pretherapeutic bacterial titer and leukocyte count. Higher leukocyte counts early in the course of the disease prior to therapy were associated with a favorable outcome. Continued leukocyte elevation after therapy was associated with a poor prognosis. No correlations were found between inoculum size and subsequent bacterial titers; however, the bacterial titer immediately prior to therapy correlated negatively with the level of the early white cell response. The best prognostic information was obtained from the multivariate analysis of inoculum size and pretherapeutic white cell response.