Painless osteoid osteoma in a metacarpal

Osteoid osteoma is a benign primary tumour of bone occurring in the first two decades of life. It presents with pain and is uncommon in the hand, particularly so in the metacarpals. We report a painless osteoid osteoma affecting a metacarpal.

Chlorzoxazone pharmacokinetics as a marker of hepatic cytochrome P4502E1 in humans

OBJECTIVE

Previous in vitro studies have demonstrated that hepatic P4502E1 metabolizes chlorzoxazone (CZX, a commonly used muscle relaxant) to 6-hydroxychlorzoxazone (6-OH-CZX). We thus assessed whether measurement of the plasma 6-OH-CZX/CZX ratio after a CZX challenge could serve as a marker of hepatic P4502E1 content.

METHODS

Three subject groups were included: recently drinking alcoholics (N = 6), abstinent alcoholics (N = 5), and nonalcoholic subjects with liver disease (N = 5) undergoing liver biopsy. Excess tissue was procured for immunochemical determination of hepatic P4502E1 content. Within an hour of the biopsy, 750 mg CZX was administered orally and serial plasma samples were collected for 6 h.

RESULTS

Recently drinking alcoholic subjects had a higher area under the curve for plasma 6-OH-CZX (1.354 +/- 0.258 microg x min x ml(-1)) then abstinent alcoholic subjects (0.296 +/- 0.080 microg x min x ml(-1), p < 0.005) and subjects with nonalcoholic liver disease (0.428 +/- 0.061 microg x min x ml(-1), p < 0.005). The use of the plasma 6-OH-CZX/CZX ratio at 90, 120, and 180 min discriminated between recently drinking alcoholic and nondrinking subjects. Hepatic P4502E1 content significantly correlated with the maximal 6-OH-CZX concentration (r = 0.76, p = 0.001) and other pharmacokinetic parameters. In the recently drinking group, the area under the curve for plasma 6-OH-CZX significantly decreased after 8 days of abstinence.

CONCLUSIONS

Measurement of plasma 6-OH-CZX after administration of a CZX challenge can serve as a marker of hepatic P4502E1 activity and thus help avoid adverse drug reactions secondary to P4502E1 induction, particularly in heavy drinkers.

A chemical approach to systematically designate the pyranopterin centers of molybdenum and tungsten enzymes and synthetic models

The recent growth in the chemistry of the oxo-molybdenum enzymes has demonstrated the need for developing systematic methods for naming and abbreviating the novel pterin cofactors that bind to the metal ion via the sulfur atoms of an ene-1,2-dithiolate moiety. Historically, the term "molybdopterin" was coined to designate a special pterin that binds molybdenum and the molybdenum-bound form was termed the "molybdenum cofactor". However, recent studies have demonstrated that this novel pterin also binds tungsten. Furthermore, considerable variation has been found in the pterin entity itself. Taken together, these facts show that molybdenum- and tungsten-containing enzymes possess a family of cofactors rather than a single "molybdenum cofactor". This article proposes a unified methodology for describing these cofactors and their metal-free pterin units in light of recent results from protein crystallography. The various numbering schemes that have been used for this heterocycle are considered, as well as the IUPAC rules which are currently being used for related tricyclic compounds. A unified methodology for uniquely designating and abbreviating each cofactor is proposed. The available chemical and spectroscopic information on the pyranopterin entities that are present in the molybdenum and tungsten enzymes, the precursors to these centers, and synthetic pyranopterins are in part the basis of the systematic names and simplifying abbreviations.

Molecular diagnosis of myotonic dystrophy and Huntington's disease from Calcutta, India

It has been identified that the expansion of normally polymorphic CTG repeats in myotonin protein kinase (DM-PK) gene in myotonic dystrophy (DM) and CAG repeats in huntingtin gene in Huntington's disease (HD) acts as the causative mutation. This hasimproved the ability of molecular diagnosis of these diseases. On molecular genetic screening of 40 normal chromosomes from people living in and around Calcutta, we have obtained 10 distinct alleles at the DM locus, with an estimated heterozygosity of 0.83. We have also observed 10 alleles at the HD locus on 32 chromosomes, with an estimated heterozygosity of 0.79. We further report here that at the DM locus, in two clinically diagnosed heterozygous individuals, the expanded alleles were of sizes 330 repeats and 1400 repeats respectively; the allele on the homologous chromosome was within the normal repeat range for both these individuals. Of two HD patients, one carried an expanded allele of size of 57 repeats, the other allele being in the normal range; while the second patient had both the alleles in the normal range.

Embryogenesis and plant regeneration from callus cultures derived from unpollinated ovaries of Hyoscyamus muticus L

Unpollinated ovaries of Hyoscyamus muticus L. (commonly known as Egyptian henbane) were cultured on Murashige and Skoog and Bourgin and Nitsch media supplemented with various growth hormones to study the organogenesis, embryogenesis and regeneration of plantlets. Embryogenesis was reported for callus grown on both media containing 0.05 mg/l α-naphthaleneacetic acid and 0.5 mg/l 6-benzylaminopurine. Differentiation of roots and shoots from the calli also occurred in these media. Albinism or chlorophyll deficiency and variation in ploidy level were observed among the ovary-derived plantlets.

Efficacy of a high and accelerated dose of hepatitis B vaccine in alcoholic patients: a randomized clinical trial

PURPOSE

A randomized, double-blind trial was conducted to compare the efficacy of a high-dose versus standard-dose hepatitis B vaccine in alcoholic patients.

PATIENTS AND METHODS

One hundred ten alcoholic patients were randomized to either receive the standard dose (20 micrograms at 0.1, and 6 months) or a high dose (40 micrograms at 0, 1, 2, and 6 months) of recombinant hepatitis B vaccine (Engerix-B). Patients were monitored for relapse of drinking using self-report, serial serum carbohydrate deficient transferrin, and collateral verification. The final titer of antibody to hepatitis B surface antigen (anti-HBs) was obtained 12 months after the first vaccine dose; a seroconversion was defined as a titer greater than 10 mlU/ml.

RESULTS

One hundred subjects completed the study; 10 of these had clinical or pathological evidence of cirrhosis. Thirty-six out of 48 (75%) of patients administered the high-dose regimen seroconverted compared with 24 of 52 (46%) in the standard dose group (P < 0.005). The mean anti-HBs titer of the high dose group was significantly greater than of the standard dose group (76.4 versus 39.4 mlU/ml, P < 0.01). Logistic regression demonstrated a significant effect on seroconversion for the vaccine dose (P < 0.005) and serum albumin (P = 0.05) but not for the other variables such as race, age, drinking during the study, serum creatinine, arm muscle circumference, and cirrhosis.

CONCLUSIONS

A high- and accelerated-dose regimen of hepatitis B improves the serological response in alcoholic patients. This regimen (currently recommended for hemodialysis patients) should now also be considered for patients with a history of alcoholism.

Detection of orthopaedic implants by airport metal detectors

We have assessed the effect of a variety of implants commonly used in fracture fixation and joint replacement on the activation of metal detectors at airport security gates. A volunteer with metal implants strapped on and patients with implants in situ walked through the device. Implants used in fixation do not activate it, except for Richards cannulated screws. An Austin-Moore prosthesis does set off the detector, but a single joint replacement does not. Three or four joint replacements activate the alarm and patients with these implants should be warned of this possibility.

Utility of carbohydrate-deficient transferrin as a marker of relapse in alcoholic patients

Carbohydrate-deficient transferrin (CDT) has been proposed as a marker of alcoholism. However, its role in monitoring alcoholic patients for relapse has not been extensively studied. We therefore performed sequential serum CDT measurements using a microcolumn/radioimmunoassay method (Kabi Pharmacia, Piscataway, NJ) in 86 male alcoholics participating in a hepatitis vaccination program who were monitored for relapse using self-report and collateral history (when available). The maximum serum CDT was significantly higher in patients who relapsed (n = 38) (33.1 +/- 3.1 mg/liter), as compared with abstinent subjects with collateral verification (n = 39) (18.8 +/- 1.3, p < 0.001) and abstinent patients without collateral verification (n = 9) (17.4 +/- 1.3, p < 0.01). Using the manufacturer's currently recommended threshold of 20 mg/liter for males, serum CDT was elevated in 29 of 38 patients who relapsed (sensitivity 76.3%). In 16 (42.1%) of the relapsed patients, a serum CDT above this threshold preceded the patient's self-report by at least 28 days. However, serum CDT exceeded 20 mg/liter in 10 of 48 patients who remained sober (specificity 79.2%); three of these patients had clinical and/or pathological evidence of cirrhosis. Using a threshold of 25 mg/liter, 21 of 38 patients who relapsed had an elevated serum CDT (sensitivity 55.3%); 12 (31.6%) of these patients had elevated serum CDT before self-report. Only 4 of 48 subjects who remained sober had serum CDT levels that exceeded 25 mg/liter (specificity 91.7%); three of these patients had clinical and/or pathological evidence of cirrhosis. In conclusion, serial serum CDT testing detects relapses before self-report in male subjects. Values between 20-25 mg/liter suggest relapse, but call for collateral verification, whereas CDT values above 25 mg/liter are usually diagnostic of relapse in the absence of cirrhosis.

Food safety and inspection service update on food safety of animals derived from biotechnology experiments

Recent progress in the field of biotechnology and the production of transgenic livestock has raised a question regarding the need for the regulation of these animals. There is also the need to regulate nontransgenic animals resulting from transgenic animal research. It is anticipated that several governmental agencies will be involved in regulatory issues pertaining to these animals. The United States Department of Agriculture (USDA), Food Safety and Inspection Service (FSIS) will ultimately be responsible for ensuring that transgenic animals intended for human consumption are wholesome, unadulterated, and properly labeled. The FSIS has implemented a program for the regulation of slaughtering nontransgenic animals resulting from transgenic animal experiments. However, the FSIS has not yet approved any transgenic livestock for slaughter. Scientists from the FSIS, in conjunction with other government agencies, are currently developing guidelines for the slaughter of transgenic animals.

Effect of bile acid perfusion on colonic motor function in patients with the irritable colon syndrome

A study was performed to determine the effect of bile acid perfusion on motility in the sigmoid colon of patients with the irritable colon syndrome compared with normal subjects. Deoxycholic acid (15 mM) statistically significantly increased motility in normal subjects (control 25.0 +/- 6.4%, perfusion 71.4 +/- 7.2%, P < 0.05) but neither chenodeoxycholic acid nor cholic acid had any apparent effect. In patients with the irritable colon syndrome, however, deoxycholic acid at 5 mM concentration (control 29.8 +/- 4.2%, during perfusion 57.4 +/- 6.5%, P < 0.05) as well as at 15 mM concentration (control 19.4 +/- 5.7+, perfusion 57.8 +/- 9.6%, P < 0.05) statistically significantly increased rectosigmoid motility. Patients with the irritable colon syndrome had a high resting 0.033-0.066 Hz (2-4 c/m) electrical activity, whereas in normal subjects 0.1-0.15 Hz (6-9 c/m) activity was greater. However, there was no statistically significant alteration in either electrical rhythm during the period of bile acid perfusion. In conclusion, additional evidence is presented to suggest that deoxycholic acid is the only bile acid likely to be implicated in the motor disorder of the irritable colon syndrome.

Is there a myoelectrical abnormality in the irritable colon syndrome?

Although recent work has suggested that an abnormality of the 0.05 Hz (3 c/m) slow wave electrical activity exists in the distal colon of patients with the irritable colon syndrome, it is not established whether this is related to altered bowel habit alone, or whether it is specific to the irritable colon syndrome. We have therefore studied 10 patients referred with this disorder and compared their colonic myoelectrical pattern with 10 patients suffering from assorted disorders with similar symptoms--for example, chronic pancreatitis, diverticular disease, ulcerative colitis, etc. Transit time, stool weights, percentage motility, and slow wave electrical activity were measured in each patient. The two groups were well matched for age and patients with similar symptoms in the two groups had similar values for transit time and percentage motility. There was a statistically significant increase in the 3 c/m electrical activity in patients with the irritable colon syndrome unrelated to the degree of diarrhoea or constipation. It would appear, therefore, that the abnormally high incidence of 3 c/m electrical activity in the colon is specific to the irritable colon syndrome and not merely a feature of altered bowel habit.