Stability of human methanogenic flora over 35 years and a review of insights obtained from breath methane measurements.

BACKGROUND & AIMS: Breath methane measurements reflect the in situ activity of the methanogenic colonic flora. Thirty-five years ago we found that 34% of healthy adult subjects were methane producers (breath methane level >1 ppm above atmospheric methane levels). The current study presents a new survey of breath methane levels designed to determine if the activity of the methanogenic flora has changed over the past 35 years. In addition, we review insights into the methanogenic flora that have resulted from breath methane measurements. METHODS: The end-alveolar breath methane concentrations of 212 healthy adults living in the Minneapolis area were determined via gas chromatography. The influence of sex, age, and bowel movement frequency on methane production was assessed. RESULTS: The findings that 36.4% of participants were methane producers, with a mean methane concentration in these producers of 16.6 ppm, are strikingly similar to the values of 33.6% and 15.2 ppm observed 35 years ago. Neither sex nor age showed a statistically significant relationship to methane production. There was a negative correlation between frequency of bowel movements and breath methane concentration in methane producers. CONCLUSIONS: The activity of the methanogenic flora of healthy adults remained remarkably stable over the past 35 years despite widespread antibiotic use and dietary changes. A literature review revealed that many associations have been shown between methane production and clinical states, but it remains to be determined if methanogens actively influence human physiology or are simply a marker of colonic function.     

Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand

Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml ^-1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml ^-1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-² week^-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.     

O,O′-二烷基-O″-(5-取代-3-苯并噻吩乙腈肟)磷酸酯及硫代磷酸酯的合成

合成了18个O,O′-二烷基-O″-(5-取代-3-苯并噻吩乙腈肟)磷酸酯及硫代磷酸酯类化合物(Ⅰ_1～18)。初步杀螺试验结果表明,其中5个化合物,即Ⅰ_2,3,7,11,12有明显的杀螺增效作用。     

Beta irradiation of recurrent ptergia: results and complications.

Although postoperative beta irradiation for prevention of pterygium recurrence is widely used, its complication rate has not been widely appreciated. Thirty-six patients underwent pterygium excision followed by irradiation with 90Sr to between 1600 and 5300 cGy (median 2400) in two to four fractions over 7 to 27 days. A median of three fields were used in each treatment course (range two to 10). Most patients had undergone previous treatment for their pterygia, including surgery alone (25 patients), or both surgery and irradiation (5 patients). Overall, recurrences developed in 10 eyes (28%). Recurrence occurred in one eye after re-irradiation (20%), compared to 9 of 31 (29%) previously non-irradiated eyes (p greater than 0.1). There was no association with number of excisions and recurrences, although all but 6 patients had undergone more than one excision. Thirteen patients (36%) developed complications including: epithelial defect or corneal thinning (3), symblepharon (5), cataract (4) and corneal ulceration (1). Complications developed in 4 of the 5 (80%) re-irradiated eyes compared to 9 of 31 (29%) previously non-irradiated eyes (p less than 0.05). The power of the statistical analysis was limited by sample size, but no significant association was observed between the development of complications or recurrences and total dose, number of abutting fields, number of previous surgical excisions or patient age, even when re-irradiated patients were excluded. Recently described calibration uncertainties with the 90Sr applicator may explain in part these complications. Alternatively, technical factors such as the number of fields or volume treated may play a role. Excessive complications and recurrences with the use of postoperative beta irradiation in this series emphasize the danger of re-treatment and the need for alternative safe and effective therapies.     

Neuroleptic malignant syndrome and serotonin syndrome in the critical care setting: case analysis.

BACKGROUND: Serotonin syndrome (SS) and neuroleptic malignant syndrome (NMS) are medical emergencies associated with psychotropic administration. Differentiation and treatment can be complex, especially when features of both syndromes are present and the patient has taken both serotonergic and neuroleptic agents. METHOD: Case analysis of a poly-drug overdose (venlafaxine, topiramate, divalproex sodium, risperidone, and carbamazepine) presenting with mixed SS/NMS features and whose clinical management suggests a practical algorithm for treatment of undifferentiated SS/NMS in critical care settings. RESULTS: The suggested algorithm includes: 1) Supportive care and withdrawal of all potentially offending agents; 2) Laboratory evaluation with prompt initiation of treatment for both disorders--cyproheptadine for SS and dantrolene for NMS; 3) Do not use bromocriptine (contraindicated in SS) or chlorpromazine (contraindicated in NMS) initially; 4) Add bromocriptine when clinical presentation becomes consistent with NMS (SS can be prolonged if serotonergic agent has long half-life). CONCLUSIONS: Prompt and appropriate identification and intervention are essential for successful management of SS and NMS. The suggested treatment algorithm allows for specific treatment of both disorders and avoids potentially exacerbating either one. The algorithm derived from this case could serve as both a practical guideline and impetus for further investigation in light of increasing psychotropic co-administration.     

Renal size and function after cure of Wilms' tumour.

Now that most patients with Wilms' tumour are cured, it is practicable to study the long-term morbidity of their treatment and use this information to reduce treatment sequelae in the future. In this study we evaluate the size and function of the remaining kidney in 53 survivors of Wilms' tumour with a mean off treatment follow-up of 13 years. There was evidence of renal dysfunction in 17 (32%), including ten (19%) with a low GFR (< 80 ml/min/1.73 m2SA), six (11%) with hypertension and five (9%) with increased urinary albumin excretion. Measurements of renal size showed 'good' renal compensatory hypertrophy in only 55% of patients. 'Good' refers to renal size of more than 2 s.d. above the mean renal length for children with two kidneys. There were no correlations between GFR, renal size, blood pressure, microalbuminuria or type of treatment. However, children less than 24 months at diagnosis and children receiving chemotherapy with radiation doses to remaining kidney of more than 1200 cGy had a worse renal prognosis. Patients whose Wilms' tumour is diagnosed in infancy should have careful long-term follow-up of renal function and size. Older patients may safely be followed up less often, unless their remaining kidney was received > 1200 cGy.