Outpatient management of warfarin therapy: comparison of computer-predicted dosage adjustment to skilled professional care

In a prospective, randomized clinical trial, we compared the accuracy of warfarin dosage-adjustments predictions using a computer program to the skill of an experienced anticoagulation nurse-specialist. The computer program predicts the steady state warfarin dose by applying Bayesian forecasting techniques to a mathematical model of the dynamic pharmacologic response to warfarin. Fifty patients who were receiving chronic warfarin therapy and who required a dosage adjustment because their prothrombin time was greater than or equal to 2 s away from their target prothrombin time were enrolled. The baseline characteristics of each group were similar, including the mean of the absolute value of the differences between initial prothrombin times and corresponding target prothrombin times. After a new a new warfarin dose was predicted, the prothrombin time was measured at least 7 days after dosage adjustment. Overall, the results in each group were comparable. There was no significant difference between groups and the mean of the absolute value of the differences between final prothrombin times and target prothrombin times, nor was there a difference in the proportion of patients who had a final prothrombin time within 2 s of the target prothrombin time. We conclude that the accuracy of warfarin dosage adjustments made using computer modeling is comparable to the skill of an anticoagulation nurse-specialist.

The glomerular changes in children with reflux nephropathy

While heavy proteinuria and focal segmental glomerulosclerosis (FSGS) are well-recognized features of progressive reflux nephropathy in adults, little is known of their early evolution. We have studied the glomerular changes in renal biopsy specimens obtained from 24 patients aged 5.2-18.8 years, in whom urinary protein excretion was measured as early morning urine protein creatinine ratios, using the Coomassie blue dye-binding method. Segmental sclerotic lesions were found in eight biopsies and traced through serial sections to a hilar origin in every instance. There was a strong positive correlation between the extent of glomerular involvement and the amount of proteinuria (P less than 0.0001). Parahilar hyaline deposits were observed in 16 biopsies, including five of the eight showing FSGS. All unsclerosed glomeruli were enlarged, and the hilar arterioles showed both enlargement and thickening, their walls frequently containing subendothelial hyaline deposits. Since in most patients renal function was comparatively well preserved, despite extensive loss of renal substances, we believe that these glomerular and vascular changes represent the stages in the evolution of hyperfiltration. Microproteinuria is the earliest clinical manifestation of FSGS, and should be sought routinely in all patients with reflux nephropathy.

Early morbidity after total hip replacement: rheumatoid arthritis versus osteoarthritis

The authors used the California Health Facilities Discharge data for 1984 and 1985 to compare retrospectively in-hospital morbidity and mortality of all 721 patients with rheumatoid arthritis versus all 8,859 patients with osteoarthritis who underwent a non-emergent, first-time, unilateral total hip arthroplasty. The lengths of hospitalization, in-hospital mortality rates, and incidences of postoperative complications were similar in the two groups except for higher rates of wound infection and wound dehiscence in the patients with rheumatoid arthritis and a higher rate of thromboembolic events in the osteoarthritis group. The short-term outcome of patients with rheumatoid arthritis appears comparable to that of patients with osteoarthritis.

Biosynthesis of methanopterin

The biosynthetic pathway for the generation of the methylated pterin in methanopterins was determined for the methanogenic bacteria Methanococcus volta and Methanobacterium formicicum. Extracts of M. volta were found to readily cleave L-7,8-dihydroneopterin to 7,8-dihydro-6-(hydroxymethyl)pterin, which was confirmed to be a precursor of the pterin portion of the methanopterin. [methylene-2H]-6-(Hydroxymethyl)pterin was incorporated into methanopterin by growing cells of M. volta to an extent of 30%. Both the C-11 and C-12 methyl groups of methanopterin originate from [methyl-2H3]methionine, as confirmed by the incorporation of two C2H3 groups into 6-ethyl-7-methylpterin, a pterin-containing fragment derived from methanopterin. Cells grown in the presence of [methylene-2H]-6-(hydroxymethyl)pterin, [ethyl-2H4]-6-[1 (RS)-hydroxyethyl]pterin, [methyl-2H3]-6- (hydroxymethyl)-7-methylpterin, [ethyl-2H4, methyl-2H3]-6-[1 (RS)-hydroxyethyl]-7-methylpterin, and [1-ethyl-3H]-6-[1 (RS)-hydroxyethyl]-7-methylpterin showed that only the non-7-methylated pterins were incorporated into methanopterin. Cells extracts of M. formicicum readily condensed synthetic [methylene-3H]-7,8-H2-6-(hydroxymethyl)pterin-PP with methaniline to generate demethylated methanopterin, which is then methylated to methanopterin by the cell extract in the presence of S-adenosylmethionine. These observations indicate that the pterin portion of methanopterin is biosynthetically derived from 7,8-H2-6-(hydroxymethyl)pterin, which is coupled to methaniline by a pathway analogous to the biosynthesis of folic acid. This pathway for the biosynthesis of methanopterin represents the first example of the modification of the specificity of a coenzyme through a methylation reaction.

Management of urinary tract infection and vesicoureteric reflux in children. 1. Operative treatment has no advantage over medical management

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The clinical significance of the glomerular location of segmental lesions in focal segmental glomerulosclerosis

Serial sections of renal biopsies obtained from 44 nephrotic children with focal segmental glomerulosclerosis (FSGS) were reviewed in order to determine the glomerular location of segmental lesions and relate the findings to the outcome of illness. There were 23 boys and 21 girls aged 0.9-14.2 years at onset. FSGS was classified as "hilar" in biopsies containing at least one lesion contiguous with or involving the hilum, regardless of the location of other lesions, and as "peripheral" in the absence of hilar lesions. Of the 44 initial biopsies, 33 were designated hilar and 6 peripheral; the remaining 5 were unclassifiable as it was not possible to determine the location of 1-3 lesions in each biopsy. Twenty-eight of the 33 hilar biopsies also contained peripheral lesions, including paratubular (glomerular "tip") lesions in 15 instances. Paratubular lesions as the predominant abnormality were observed in only four biopsies. Repeat biopsies showed that transition occurred from one type to another, and only 4 biopsies remained with a final designation of peripheral FSGS. After a follow-up period of 1.6-24.9 years (mean 9.3), there was no significant difference in outcome between hilar and peripheral FSGS, whether diagnosed on the initial or repeat biopsy. The division into separate categories is not clearcut, and the use of this as a prognostic aid does not justify the additional cost of preparing and examining numerous serial sections.

Deep-vein thrombosis after fracture of the pelvis: assessment with serial duplex-ultrasound screening

Sixty patients who had had a major fracture of the pelvis and were in stable condition on the orthopaedic ward three to five days after the injury were tested serially with duplex ultrasound, beginning approximately seven days after the injury, in order to determine the incidence of deep-vein thrombosis. Contrast venography was performed to confirm all positive non-invasive studies. Deep-vein thrombosis developed in eight patients (approximately 15 per cent). The thrombosis was in the popliteal or a more proximal vein in six of the eight patients, whereas in two it was distal to the popliteal vein. In four patients, evidence of thrombosis developed after one or more normal duplex-ultrasound studies. In one patient, symptoms that were suggestive of deep-vein thrombosis developed fifty-two days after the injury (four days after the fourth normal duplex-ultrasound examination), and ascending venography was entirely normal. Another patient had a pulmonary embolus fifteen days after the injury, and on the same day a duplex-ultrasound study was positive for thrombosis. During six weeks of follow-up after discharge from the hospital, symptoms of deep-vein thrombosis or pulmonary embolism did not develop in any patient in whom serial duplex-ultrasound studies had been negative.

Widespread occurrence of 2-acetylthiazole-4-carboxylic acid in biological material

2-Acetylthiazole-4-carboxylic acid was shown to be widely distributed in all organisms tested, which included members of the eukaryotes, archaebacteria, and eubacteria. This thiazole, which was identified and quantitated as the methyl ester methoxyamine derivative, was found in these organisms at levels of from 27 to 1100 nmol/g dry weight (d.wt) of tissue. On the basis of its widespread occurrence, the levels at which it occurs in these organisms, and its chemical structure, which contains a reactive carbonyl group, it is proposed that this compound is a previously undescribed coenzyme.

Biosynthesis of caldariellaquinone in Sulfolobus spp

The biosynthesis of caldariellaquionone (CQ) was studied in species of Sulfolobus by measuring the incorporation of stable isotopically labeled tyrosines into CQ. By feeding a series of tyrosines labeled with deuterium or 13C and then measuring the extent and position at which label was incorporated into CQ by mass spectrometry, it was shown that more than 95% of the label was incorporated into the benzo[b]thiophen-4,7-quinone moiety of CQ. From the labeling experiments, it is concluded that the benzo[b]thiophen-4,7-quinone is derived as an intact unit from all of the carbons of tyrosine except C-1.

Steps in the conversion of alpha-ketosuberate to 7-mercaptoheptanoic acid in methanogenic bacteria

The biosynthetic steps involved in the conversion of alpha-ketosuberate to 7-mercaptoheptanoic acid were studied in cell-free extracts of methanogenic bacteria. The pathway was established by measuring the incorporation of stable isotopically labeled precursors into the S-methyl ether methyl ester derivative of the enzymatically generated 7-mercaptoheptanoic acid by using gas chromatography-mass spectrometry (GC-MS). Quantitation of the 7-mercaptoheptanoic acid produced in the incubations with the substrates was accomplished by using an internal standard of 6-mercaptohexanoic acid. [4,4,6,6-2H4]-2-Oxosuberic acid, [7-2H]-7-oxoheptanoic acid, [2-2H]-2(RS)-(5-carboxypentyl)thiazolidine-4(R)-carboxylic acid, and S-(6-carboxyhexyl)cysteine were each shown to be converted to 7-mercaptoheptanoic acid. Incubation of cell extracts with a mixture of 2(RS)-(5-carboxypentyl)thiazolidine-4(R)-carboxylic acid and [2-2H]-2-(RS)-(5-carboxypentyl)-[34S]thiazolidine-4(R)-carboxylic acid showed that both 34S and 2H are incorporated into the 7-mercaptoheptanoic acid but only after separation of the cysteine from the [7-2H]-7-oxyheptanoic acid portion of the molecule. Furthermore, the sulfur from the cysteine was incorporated into the thiol only after its elimination from the cysteine and subsequent mixing with an unlabeled sulfur source which had a molecular weight of sufficient size that it was excluded from Sephadex G-25. Hydrogen sulfide was found to supply the sulfur for the production of the 7-mercaptoheptanoic acid in a reaction that was shown to obtain its reducing equivalents from hydrogen via an F420-dependent hydrogenase.

Home prothrombin time monitoring after the initiation of warfarin therapy. A randomized, prospective study

STUDY OBJECTIVE

To evaluate the efficacy and accuracy of monitoring prothrombin times at home.

DESIGN

Randomized, prospective cohort study.

SETTING

Outpatients discharged from a university hospital or a community hospital.

PATIENTS

Fifty patients started on warfarin for the first time who demonstrated an ability to use the monitor and who had not achieved a stable response to warfarin in the hospital.

INTERVENTION

Oral anticoagulation therapy managed using a portable prothrombin time monitor compared with specialized anticoagulation clinic care.

MEASUREMENTS AND MAIN RESULTS

In the 46 patients who completed the 8-week study, the median percentage of time that patients in the home-monitor group (n = 23) were within a range equal to the target prothrombin ratio +/- 0.3, but always above 1.25, was 93%, compared with 75% for patients in the clinic group (n = 23) (P = 0.003). There was no significant difference between groups in the percentage of time above the therapeutic range; however, the percentage of time that patients were subtherapeutic was significantly greater in the clinic group (P less than 0.001). There were no major thromboembolic or hemorrhagic complications in either group. Differences between home monitor measurements and corresponding clinical laboratory measurements using blood samples drawn within 4 hours of the home test were comparable to differences observed between measurements using two different clinical laboratory instruments.

CONCLUSIONS

Use of a portable prothrombin time monitor by patients at home is feasible and provides accurate measurements. Patients doing home monitoring achieve superior anticoagulation control compared with those receiving standard anticoagulation clinic care.

Diagnosis of deep-vein thrombosis using duplex ultrasound

PURPOSE

To critically evaluate the accuracy, advantages, and drawbacks of duplex ultrasound as a diagnostic test for proximal deep-vein thrombosis.

DATA IDENTIFICATION

An English-language search using MEDLINE (1980 to 1988) and bibliographies from articles, and a hand search of pertinent radiology and ultrasound journals from 1988.

STUDY SELECTION

All series comparing duplex ultrasound to the reference standard, contrast venography, were reviewed and classified into levels based on the quality of study design.

DATA EXTRACTION

Results of duplex ultrasound compared with venography in the proximal deep venous system, technical problems encountered, frequency of diagnosis of other causes of leg swelling, and frequency of unsuccessful or inconclusive studies were collated.

RESULTS OF DATA SYNTHESIS

Four well-designed studies reported similar results. The sensitivity of duplex ultrasound in detecting proximal thrombi ranged from 92% to 95% with a combined sensitivity of 93% (CI, 88% to 98%), and the specificity ranged from 97% to 100% with a combined sensitivity of 98% (CI, 96% to 100%). Similar findings were noted in nine other studies that had minor methodologic flaws. Four studies reported that ultrasound was able to identify a nonthrombotic cause of leg swelling in 5% to 15% of cases. Four studies found that duplex ultrasound was inconclusive in 1% to 6% of cases, with a combined frequency of 2%.

CONCLUSIONS

Duplex ultrasound appears to be very accurate in the detection of acute proximal deep-vein thrombosis. This test has major advantages as well as certain limitations compared with other diagnostic methods.

A novel biosynthesis of medium chain length alpha-ketodicarboxylic acids in methanogenic archaebacteria

Gas chromatographic-mass spectrometric analysis on the distribution of alpha-ketodicarboxylic acids in various bacteria determined that alpha-ketoglutarate and alpha-ketoadipate are widely distributed in all the bacteria examined, whereas alpha-ketopimelate and alpha-ketosuberate are found only in the methanogenic archaebacteria. Labeling experiments with stable isotopes indicated that each of these acids arises from alpha-ketoglutarate by repeated alpha-ketoacid chain elongation. The final product in this series of reactions, alpha-ketosuberate, serves in the methanogenic bacteria as the biosynthetic precursor to the 7-mercaptoheptanoic acid portion of 7-mercaptoheptanoylthreonine phosphate, a methanogenic coenzyme.

Structural diversity among methanofurans from different methanogenic bacteria

An examination of the methanofurans isolated from a wide range of methanogenic bacteria and from Archaeoglobus fulgidus has revealed at least five chromatographically distinct methanofurans. Bacteria from each major genus of methanogenic bacteria have been found to contain a chemically different methanofuran. The nature of the differences in the methanofurans appears to lie in the modification of the side chain attached to the basic core structure of 4-[N-(gamma-L-glutamyl-gamma-L-glutamyl)-p-(beta-aminoethyl)phenoxyme thy l]-2-(amino-methyl)furan. This was supported by the structural elucidation of the methanofuran isolated from Methanobrevibacter smithii, designated methanofuran-c, which was the same as the originally characterized methanofuran except for a hydroxy group at the 2 position of the 4,5-dicarboxyoctanedioic acid moiety of the molecule.

Simplified quantification of urinary protein excretion in children

The protein/creatinine ratio (Up/Uc) measured in 71 early morning urine samples (EMU) correlated closely with timed overnight urine (ONU) protein excretion rates (r = 0.96). The relationship was linear throughout the entire range of normal and abnormal protein excretion, an ONU rate of 1 mg/h/m2 body surface area being proportional to an EMU Up/Uc of 5 mg/mmol. Using the Coomassie Blue dye-binding method the upper limit of Up/Uc in 377 apparently healthy children and adolescents aged 3-19 years was shown to be 20 mg/mmol. Albumin/creatinine ratios (Ua/Uc) were also determined in the 377 healthy subjects, yielding a normal working upper limit of 3 mg/mmol. Although in normal individuals studied longitudinally the day-to-day variation of both Up/Uc and Ua/Uc was appreciable, all measurements remained within the cross-sectional normal range. While the determination of Ua/Uc has a role in the study of "microproteinuria", it is comparatively costly for routine use. The measurement of the EMU Up/Uc avoids errors and difficulties associated with timed urine collection, simplifies sample handling by the laboratory and is inexpensive. In clinical practice this is the method of choice for the quantification of proteinuria in patients with renal disease.

Analysis and characterization of the folates in the nonmethanogenic archaebacteria

A detailed analysis of the folate coenzymes in the nonmethanogenic archaebacteria has been performed. By using the Lactobacillus casei microbiological assay for folates, the levels of folates in Sulfolobus solfataricus and Sulfolobus acidocaldarius were found to be 3.7 and 8.3 ng/g (dry weight) of cells, respectively, compared with 88,000 and 28,000 ng/g (dry weight) of cells in Halobacterium halobium and Halobacterium strain GN-1, respectively. The levels of folates found in the Sulfolobus spp. were approximately 100 times less than those found in the typical eubacterium, whereas the levels in the halobacteria were approximately 10 times higher. The folate in Sulfolobus solfataricus was shown to consist of only 5-formyltetrahydropteroylglutamate, and the folate in Halobacterium strain GN-1 was shown to consist of only pteroyldiglutamate. The low folate levels in the Sulfolobus spp. are the same as those found in the methanogenic bacteria, suggesting that another C1 carrier may function in these cells.

Poststreptococcal glomerulonephritis in children: clinicopathological correlations and long-term prognosis

Between 1962 and 1970, 36 children with acute biopsy-proven poststreptococcal glomerulonephritis (PSGN) entered a prospective long-term follow-up study. The initial biopsies were scored into four histological grades using criteria based on endocapillary proliferation, leucocyte infiltration, epithelial "hump" and crescent formation; 5 patients had grade-1 (least severe), 14 grade-2, 15 grade-3 and 2 grade-4 biopsies. Two children died from rapidly progressive glomerulonephritis; both had grade-4 biopsies. Early repeat biopsy in 12 patients showed improvement in all but one patient who progressed from grade 2 to type 2 mesangiocapillary glomerulonephritis (MCGN). The initial biopsy grade correlated significantly with heavy proteinuria (chi2 = 9.73, P less than 0.01) but not with hypertension, haematuria or renal functional impairment. Follow-up observations were made after mean periods of 9.5 years (range 5.4-12.4 years; 32 subjects) and 19.0 years (range 14.6-22 years; 30 subjects). None of the survivors had an abnormal plasma creatinine. Only one patient (grade-3 biopsy), a female with a subsequent history of recurrent pyelonephritis, was hypertensive. Isolated microscopic haematuria persisted in 1 grade-2 and 2 grade-3 subjects. One grade-2 subject had proteinuria secondary to MCGN and one grade-3 subject had mild proteinuria and borderline hypertension. Although 20% of subjects had urinary abnormalities, we conclude that the long-term outcome of PSGN in children is excellent.

Biosynthesis of the 2-(aminomethyl)-4-(hydroxymethyl)furan subunit of methanofuran

2H- and 13C-labeled precursors were used to establish the pathway for the biosynthesis of the 2-(aminomethyl)-4-(hydroxymethyl)furan (F1) component of methanofuran in methanogenic archaebacteria. The extent and position of the label incorporated into F1 were measured from the mass spectrum of the diacetyl derivative of F1. [1,2-13C2]Acetate was found to be incorporated into two separate positions of the F1 molecule as a unit. The extent of incorporation of 13C2 into each of these positions was the same as that observed for the incorporation of acetate into the alanine and proline produced by the cells. From [2,2,2-2H3]acetate, deuterium was incorporated into two separate sites of the F1 molecule, one containing up to two deuteriums and the other only one. On the basis of the fragmentation pattern of the F1 diacetyl derivative, it was determined that two deuteriums were incorporated into the hydroxymethyl group at C-4 and one was incorporated at C-3 of the furan ring. The extent and distribution of the incorporated deuterium at the C-4 methylene were the same as that observed for C-6 of the glucose produced by the cells. On the basis of this and additional information presented in this paper, it is concluded that F1 is generated by the condensation of dihydroxyacetone phosphate with pyruvate. The resulting dihydroxy-substituted tetrahydrofuran after elimination of 2 mol of water would produce the phosphate ester of 2-carboxy-4-(hydroxymethyl)furan. Reduction of the carboxylic acid to an aldehyde and subsequent transamination would produce the phosphate ester of F1.

Juvenile nephronophthisis with calcification of basal ganglia and pancreatic insufficiency

Juvenile nephronophthisis is a major cause of progressive renal failure in children. Its manifestations are varied and protean. It is a multisystem syndrome, encompassing and overlapping related disorders. We treated a 4-year-old girl who presented with various manifestations of progressive renal failure characteristic of juvenile nephronophthisis, in addition to calcification of the basal ganglia and pancreatic lipomatosis, two associated conditions hitherto undescribed. It is hoped that further reports of other associated conditions may help to clarify further the nature of this complex syndrome.

Glomerular basement membrane thickness in children. A morphometric study

Measurements of glomerular basement membrane (GBM) thickness in children with minimal change nephrotic syndrome were made on electron micrographs of 43 biopsy specimens obtained from 35 children aged 1-13 years, of whom 13 were in remission at the time of biopsy. Measurements were also made in 2 children with non-glomerular disorders. A mean of 189 measurements per biopsy were made, using prints of x6,400-12,000 magnification. Quadratic curves were fitted by regression analysis to the mean GBM thickness for each of the 35 initial nephrotic biopsies, plotted against age for the whole group and separately for sex, race and the presence or absence of proteinuria at the time of biopsy. There were no significant differences in race or proteinuria, but there was a trend towards a thicker GBM in young males which disappeared by 9 years of age. From the mean +/- 2 SD of GBM thickness for each of the 35 initial nephrotic biopsies the calculated thickness ranged from 100-340 nm at 1 year of age to 190-440 nm at 9 years of age and older. The growth curve for GBM thickness increases steeply initially, reaching a plateau at 9 years of age. Because there was no significant difference between proteinuric patients and those in remission, while measurements in the nephrotic syndrome and non-glomerular disorders closely agreed, we believe that our results demonstrate the normal GBM thickness and growth pattern.

Structure of solfapterin (erythro-neopterin-3'-D-2-deoxy-2-aminoglucopyranoside) isolated from the thermophilic archaebacterium Sulfolobus solfataricus

The structure of the major fluorescent pterin present in thermophilic archaebacterium Sulfolobus solfataricus has been assigned, by analysis of the intact molecule and its hydrolytic and periodate cleavage products, as erythro-neopterin-3'-D-2-deoxy-2-aminoglucopyranoside. The trivial name solfapterin is proposed for this compound.

Indole-3-acetic acid and 2-(indol-3-ylmethyl)indol-3-yl acetic acid in the thermophilic archaebacterium Sulfolobus acidocaldarius

Indole-3-acetic acid (IAA) and 2-(indol-3-ylmethyl)indol-3-yl acetic acid were identified in lipid extracts of Sulfolobus acidocaldarius; they occurred at concentrations of 0.57 and 0.59 mumol/g (dry weight), respectively. The amount of IAA found in these cells is more than a thousand times greater than that found in a typical extract of a plant in which IAA serves as a plant growth hormone. Neither of these compounds was detected in the other archaebacteria that were analyzed; these included Sulfolobus sulfataricus, Halobacterium salinarium, and several strains of methanogenic bacteria. This is the first report of the natural occurrence of 2-(indol-3-ylmethyl)indol-3-yl acetic acid.

Hormonal and metabolic responses to glucose infusion in sepsis studied by the hyperglycemic glucose clamp technique

Although nutritional support is vital to treatment of severe sepsis, the septic patient does not respond normally to glucose infusion. We have used the hyperglycemic glucose clamp technique to investigate the initial hormonal and metabolic responses of the septic patient to glucose under controlled conditions. The plasma glucose concentration was raised to and maintained at 12 mmol/liter for 2 hr in 12 septic patients and 11 normal controls. Glucose utilization, assessed from the amount infused, was significantly depressed in the patients, despite similar plasma insulin concentrations in the two groups. Forearm glucose uptake was similarly impaired. Despite very similar plasma free fatty acid concentrations in the two groups, which were suppressed equally by the glucose infusion, whole-body fat oxidation was elevated in the patients compared with the controls, and suppressed to a lesser extent in response to glucose. Glycerol and ketone body concentrations were elevated in the patients in keeping with a picture of accelerated release, clearance, and oxidation of fatty acids. Plasma cortisol, epinephrine, and norepinephrine concentrations were elevated in the septic patients in a severity-related manner, but not to high levels compared with experimental work. Norepinephrine showed no response to the glucose infusion in either group. Plasma glucagon concentrations were not significantly elevated in the septic patients. We conclude that the hyperglycemic glucose clamp provides a useful model for studying glucose intolerance in sepsis. Impaired glucose utilization in septic patients is associated with increased fat oxidation, although the hormonal basis for these changes is still unclear.

Initiation of warfarin therapy: comparison of physician dosing with computer-assisted dosing

In a prospective, randomized study at two university hospitals, the authors examined how effectively housestaff physicians (n = 36) managed the initiation of warfarin therapy compared with a computer-assisted dosing regimen (n = 39) using the software program Warfcalc, which was managed by one of the authors. Target prothrombin time ratios were selected by the physicians. Study endpoints included: the time to reach a therapeutic prothrombin ratio, the time to reach a stable therapeutic dose, the number of patients transiently overanticoagulated, the number of bleeding complications, and the accuracy of the predicted maintenance dose, which was assessed at steady-state 10-14 days later. Computer-assisted dosing consistently out-performed the physicians: a stable therapeutic dose was achieved 3.7 days earlier (p = 0.002), fewer patients were overanticoagulated (10% versus 41%), and the predicted maintenance dose was in the therapeutic range in 85% of the computer-dosed patients versus 42% of the physician group (p less than 0.002). For physicians who did not routinely manage warfarin therapy, computer-assisted dosing improved the accuracy of dosing and shortened the time required to achieve a stable therapeutic dose.

Ocular signs in Alport's syndrome

The eyes of sixty one patients with Alport's syndrome or its variant, and of 25 unaffected relatives, were examined. Details of ocular signs associated with Alport's syndrome are presented and related to renal prognosis and family history.

Occurrence of coenzyme F420 and its gamma-monoglutamyl derivative in nonmethanogenic archaebacteria

Analysis of the fluorescent compounds extracted from six different species of halobacteria and one species each of Sulfolobus and Thermoplasma revealed the universal occurrence of coenzyme F420, (N-[N-[O-[5-(8-hydroxy-5-deazaisoalloxazin-10-yl)-2,3,4-trihydroxy -4-pentoxyhydroxyphosphinyl]-L-lactyl]-L-gamma-glutamyl]-L -glutamic acid), or its gamma-monoglutamyl derivative or both. The total amount (approximately 100 pmol/mg [dry weight]) of these compounds found in the halobacteria studied was approximately 5% of the amount previously reported for methanogenic bacteria. The amount of F420 found in the Sulfolobus and Thermoplasma strains was approximately 1% of that found in the halobacteria. The major compound in all but one of the examined strains was the gamma-monoglutamyl derivative of F420; one strain of halobacteria contained only F420. For the halobacterium-derived samples, the additional glutamic acid was shown to be linked by a gamma-glutamyl peptide bond to the terminal glutamic acid of the F420 core structure by enzymatic hydrolysis of the samples with three different gamma-glutamyltranspeptidases. The product of this enzymatic hydrolysis was F420 with one less glutamic acid in the side chain.

The shoulder impingement syndrome: prevalence of radiographic findings and correlation with response to therapy

The shoulder impingement syndrome is believed to be caused by compression of the rotator cuff tendons and subacromial bursa between the humeral head and structures that make up the coracoacromial arch. Plain film findings were tabulated for 36 patients, 22-81 years old, who had signs and symptoms of an acute impingement syndrome. The most common radiographic abnormalities were subacromial bony proliferation in 68%, degenerative changes in the greater tuberosity of the humerus in 66%, and degenerative joint disease in the acromioclavicular joint in 66%. There was evidence of calcium deposition in the rotator cuff in 37%, inferiorly oriented acromioclavicular osteophytes in 32%, and degenerative changes of the lesser humeral tuberosity in 29%. The acromiohumeral space was narrowed in only 21%. The radiographic findings were scored blindly and compared to the treatment outcome of 6 weeks of medical therapy. There was no statistically significant correlation between any of the radiographic findings and the response to medical therapy. The results suggest that radiographic findings are extremely common in patients with the acute impingement syndrome, but that they are not useful as prognostic indicators of the short-term response to medical treatment.

X-linked mesangiocapillary glomerulonephritis

Two related male patients with mesangiocapillary glomerulonephritis (MCGN) are described demonstrated by renal biopsy, inherited as an X-linked disorder. Family investigations failed to reveal any underlying immunological defects or a marker for the female carrier state. The age at diagnosis, the result of discovery of proteinuria on routine urine testing during infancy, is earlier than in any other reported cases of MCGN. This raises the possibility that this variety of MCGN may develop in utero and be detectable by alpha-fetoprotein maternal screening.

Asymptomatic microscopical haematuria

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Haemolytic-uraemic syndrome: clinical experience of an outbreak in the West Midlands

In 1982-3, 35 children from the West Midlands developed the haemolytic-uraemic syndrome. This was a higher incidence than expected and included an epidemic localised to the Wolverhampton area in July 1983 which comprised 11 cases in two weeks. Twenty three children were treated with dialysis, of whom three died. Six patients developed chronic renal failure, four of them from Wolverhampton. Extrarenal manifestations included neurological sequelae in four, two of whom also developed insulin dependent diabetes mellitus and chronic renal failure. Cardiomyopathy occurred in one child, who also had chronic renal failure. The outcome of these 35 patients was not predictable from prognostic criteria derived from previous experience in Britain. This, together with the high prevalence of extrarenal disease and the geographical localisation of the 1983 outbreak, suggested an aetiological agent new to the region. Faeces from 10 patients were examined for verotoxin producing Escherichia coli, and positive strains of serotype O157.H7 were found in three patients during the Wolverhampton outbreak.

Rotator cuff tendinitis: comparison of subacromial injection of a long acting corticosteroid versus oral indomethacin therapy

Using a prospective, double blind, double dummy protocol, we compared the efficacy of subacromial injection of 40 mg of triamcinalone acetonide versus oral indomethacin, 100 mg/day, in 40 patients with acute rotator cuff tendinitis. Repeat injection and refill of medication was given after 3 weeks, if necessary. At 6 weeks, there was no significant difference between the 2 groups with respect to the percentage of patients who improved (60 vs 66%) or the magnitude of the change of pain and motion variables. This study suggests that there is essentially no difference in the short term efficacy of oral nonsteroidal therapy compared to local corticosteroid injection(s) in the treatment of rotator cuff tendinitis.

Tocainide suppression of immune-complex-mediated dermal inflammation: comparison with prostaglandin E1

Local anesthetic agents have been shown to alter a variety of polymorphonuclear leukocyte (PMN) functions and may be useful as anti-inflammatory agents. We compared the anti-inflammatory effects of therapeutic doses of the recently released local anesthetic-antiarrythmic drug tocainide to pharmacologic doses of prostaglandin E1 (PGE1) on immune-complex-mediated dermal inflammation in female Sprague-Dawley rats. Intense dermal inflammation was produced using a classic reverse passive Arthus reaction, and the inhibition of PMN accumulation in the subdermis was quantitated in biopsy samples taken 2.5 hr after the reaction was initiated and the drug was given. Using a light microscope with a counting grid, biopsy sections were randomly sampled in a blinded fashion and an inflammation index equal to the ratio of PMNs to fibroblasts was determined for each animal. The mean inflammation index in 10 animals given 25 mg of tocainide (mean serum level = 14.6 micrograms/ml) was 9.3 +/- 1.2 (+/- SEM), which was significantly less than the index of 17.7 +/- 2.5 in 10 control animals (P less than 0.025). Similarly, the five animals that received either 500 or 250 micrograms of PGE1 had a significantly reduced index, with the effect of 250 micrograms PGE1 comparable to the effect of the tocainide. These findings suggest that therapeutic levels of tocainide reduce the accumulation of PMNs in immune-complex-mediated dermal inflammation; thus, local anesthetic agents may be useful in the treatment of certain inflammatory disorders.

Reduction of serum testosterone levels during chronic glucocorticoid therapy

The effect of chronic glucocorticoid therapy on serum testosterone levels was studied in men aged 67 +/- 4 (SD) years with chronic pulmonary disease. The serum testosterone level was reduced in 14 of 16 patients to a mean value of 211 +/- 93 ng/dL, compared with 449 +/- 111 ng/dL in 11 age- and disease-matched control patients (p less than 0.001). The corticosteroid dosage and the serum testosterone level were inversely related (r = -0.78). Testosterone binding to serum proteins was not significantly affected. Basal gonadotrophin levels were not elevated while their secretory responses to exogenous gonadotrophin-releasing hormone (GnRH) were intact. We conclude that glucocorticoid therapy commonly reduces serum testosterone levels in older men due to alteration of hypothalamic GnRH secretion.

Biosynthesis of the 7-methylated pterin of methanopterin

The incorporation of [15N]glycine and [U-methyl-2H]methionine into methanopterin by growing cells of a methanogenic bacterium was measured to establish the biosynthetic route of the methylated pterin in the structure. The tetrahydromethanopterin produced by the cells was oxidatively cleaved to produce 7-methylpterin, and the amount of label incorporated into this pterin was measured by gas chromatography-mass spectrometry of the ditrimethylsilyl derivative of this compound. Approximately 27% of the 7-methylpterin and the guanine present in the cell was derived from the fed [15N]glycine. [U-methyl-2H]methionine was incorporated with the initial retention of all three deuteriums. These results are consistent with the biosynthesis of the pterin of methanopterin originating from GTP and its 7-methyl group arising from the methyl group of methionine.

Steroid responsive nephrotic syndrome is more common in Asians

A retrospective study was undertaken to determine the incidence and compare the natural history of steroid responsive nephrotic syndrome in Asian, European, and Afro-Caribbean children born in the United Kingdom and living in Birmingham. Patients were identified from hospital admission records during the years 1979-83. Baseline population data were obtained from the same area using city birth statistics. There were 27 Asian, 13 European, and 2 Afro-Caribbean patients, giving annual incidences of 16, 2.6, and 3.1 per 100 000 children. The sixfold higher incidence in Asian children remains unexplained; further epidemiological studies may throw new light on the aetiology.