Biomedical subjects
Publications and source records attributed to G M Barker.
A neonate who had a ruptured exomphalos with a fetiform teratoma arising from the end of a long intestinal tubular duplication and a short gut is presented. The management is discussed and the literature is reviewed.
In order to determine the outcome and associated chromosomal and structural anomalies in fetuses diagnosed in utero as having a congenital diaphragmatic hernia, we reviewed 48 consecutive cases referred to our regional Fetal Diagnostic Unit between 1988 and 1995. All babies were delivered in units with appropriate neonatal resuscitation facilities. Thirteen babies [34 per cent of those tested, confidence interval (CI) 19-49 per cent] had karyotypic abnormalities. Three had trisomies but the other nine had more complex karyotypic abnormalities including translocations, deletions, and marker chromosomes. Twenty-one fetuses (44 per cent, CI 30-58 per cent) had additional ultrasound abnormalities which affected the heart in ten cases (21 per cent). Overall, 13 babies survived (27 per cent, CI 14-40 per cent). In babies with normal chromosomes and no additional structural abnormalities the survival rate was 50 per cent (CI 25-75 per cent). Poor outcome was not predicted by early gestation at diagnosis, the hernial contents, or the presence of polyhydramnios. We conclude that parents should be counselled about prognosis with information derived from series of prenatally diagnosed diaphragmatic hernias. The investigations offered should include a detailed ultrasound examination, particularly of the heart, and karyotyping by fetal blood sampling.
Angiostoma schizoglossae n. sp. is described from Schizoglossa novoseelandica Pfeiffer collected from a forest in central North Island, New Zealand. Angiostoma schizoglossae is distinguished from other Angiostoma species with peloderan caudal alae in the Northern Hemisphere, by combined characters of subtriangular mouth, lack of lateral alae, and, in the male, variation in position and number of the pedunculate papillae. Its occurrence among the New Zealand endemic land snail fauna extends the known range of the monogeneric Angiostomatidae to include both the Holarctic and Southwest Pacific regions. This is suggestive of the ancient emergence of the Angiostomatidae and their long association with terrestrial molluscs. A key is provided for identification of all known Angiostoma species.
The development of colorectal polyps and cancer in patients with familial adenomatous polyposis (FAP) is directly linked to inactivation of the APC gene. Other, epigenetic, mechanisms may be involved in tumorigenesis and a previous study suggested that an intrinsic difference in the biliary bile acid profile of untreated patients with FAP persisted after colectomy. Gas chromatography and gas chromatography-mass spectrometry were used to examine the biliary bile acid profiles of four groups of patients with normal gallbladders: 20 patients with an intact colon comprising 12 with FAP and eight controls; and 26 patients after colectomy comprising 12 with FAP and 14 controls. Comparison of ten different bile acids from both amidate fractions (glycine and taurine) revealed a small increase in the molar percentage of a minor bile acid (12-oxolithocholic acid) in patients with FAP and an intact colon compared with the matching control group. Colectomy was associated with a dramatic reduction in levels of secondary bile acids but with little difference between patients with FAP and controls.
Previous studies have suggested reduced formation of secondary bile acids in patients with familial adenomatous polyposis (FAP). Developments in the collection, extraction and analysis of faecal bile acids as well as in the accurate diagnosis of FAP by DNA markers prompted reinvestigation of this hypothesis. The median (interquartile range (i.q.r.)) faecal bile acid concentration (3.69 (1.66-5.36) mumol per g dry weight) and daily excretion rate (60.5 (29-149) mumol per g per 24 h) in ten patients with FAP were similar to those of nine control subjects (3.31 (0.65-8.38) mumol per g dry weight and 30.1 (7.9-228) mumol per g per 24 h). Although the median (i.q.r.) concentration of only one bile acid (12-oxo-lithocholic acid) was significantly different between patients with FAP and controls (49 (34-70) versus 0 (0-20) nmol per g dry weight, P = 0.006), the derivatives of chenodeoxycholic acid (3.35 (1.76-5.32) versus 0.51 (0.13-2.37) mumol per g dry weight, P = 0.02) and cholic acid (1.63 (0.42-2.34) versus 0.80 (0.13-3.57) mumol per g dry weight, P = 0.006) were increased in those with polyposis. These results show increased bacterial biotransformation of faecal bile acids in patients with FAP.
The purpose of this study was to determine if a correlation exists between long-term azidothymidine (AZT) therapy and low pseudocholinesterase concentrations in patients who are infected with the human immunodeficiency virus (HIV). A pilot study was conducted of 10 patients infected with HIV, 5 of whom were receiving AZT. Laboratory tests, including complete blood count (CBC), liver function tests, helper/inducer T lymphocyte numbers (CD4), serum dibucaine numbers, and serum pseudocholinesterase concentrations were examined. Control and study subjects both exhibited normal dibucaine numbers, but the pseudocholinesterase concentrations were significantly lower in the group that was not receiving AZT relative to the AZT treatment group. However, only two patients, neither of whom were receiving AZT, demonstrated low or borderline low pseudocholinesterase concentrations according to laboratory criteria. It is possible that pseudocholinesterase synthesis is significantly inhibited by the HIV disease process and that treatment with AZT partly reverses the inhibition. Associated variables contributing to low pseudocholinesterase concentrations in the HIV-positive patient are explored.
Previous studies have suggested that patients with familial adenomatous polyposis (FAP) have increased faecal excretion of cholesterol but a reduction in cholesterol metabolites. It was consequently proposed that the degree of faecal cholesterol degradation could be used as a means of diagnosis. Developments in the extraction and analysis of faecal neutral sterols as well as the accurate means of diagnosing FAP by DNA analysis and indirect ophthalmoscopy has necessitated a re-examination of this proposal. Faecal neutral sterols were analysed in 10 patients with untreated FAP following a complete 5-day stool collection and compared with 9 healthy control subjects (including 4 siblings) closely matched for age and sex. The median [25 and 75, percentiles] stool wet weights were similar between the FAP (97.5 [69, 192] g.24 h-1) and the control (116 [61.5, 137] g.24 h-1) groups. Faecal cholesterol concentration was similar in the two groups (FAP = 2.3 [1.4, 4.2]; control = 3.5 [1.0, 6.0] mumol.g-1 dry wt) as was the concentration of total neutral sterols not including plant sterols (FAP = 17.2 [13.4, 21.0]; control = 18.2 [7.4, 21.6] mumol.g-1 dry wt). There were no significant differences in the proportions of cholesterol metabolised between the FAP (82.3 [74.2, 93.5]%) and control (72.1 [5.7, 81.3]%) groups. This study does not support the notion that faecal neutral sterol metabolism is uniquely different in patients with FAP.