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Biomedical subjects

G Nicholls

Publications and source records attributed to G Nicholls.

33 records · Page 2Linked to original sources
PubMed1995

Nitric oxide-producing neurons remain intact after small bowel transplantation.

This study documents the fate of nitric oxide neurons following small bowel transplantation. Heterotopic, syngeneic small bowel transplants were performed in five male Lewis rats. The grafts were harvested 7, 36, 55, 60, and 65 days postoperatively, together with the native bowel for comparison. NADPH diaphorase staining of cryostat sections was used to identify the nitric oxide-producing neurons. NADPH diaphorase activity was concentrated in the myenteric plexus, deep muscular, and submucous plexus. No differences were detected between the transplanted and native bowel at any time after transplantation. This suggests that nitric-oxide-producing neurons are well preserved after transplantation and that posttransplant dysmotility is probably not related to interrupted nitric oxide innervation.

Animals↗
PubMed1994

Xanthogranulomatous pyelonephritis in childhood: pre-operative diagnosis is possible.

OBJECTIVE: To diagnose xanthogranulomatous pyelonephritis (XGP) in childhood pre-operatively. PATIENTS AND METHODS: Eleven cases of XGP presenting to Birmingham Children's Hospital over a 10-year-period are reported. Nine (82%) were diagnosed preoperatively on the clinical and radiological findings. RESULTS: The characteristic clinical findings were urinary tract infection (9 cases), palpable renal mass (8 cases) and anaemia (8 cases). The most common radiological findings were enlarged kidney (9 cases), renal calculi (7 cases) and non-functioning kidney (6 cases). Renal ultrasound typically demonstrated a central echoic area (6 cases) and multiple hypoechoic areas in the parenchyma (7 cases). A computed tomography (CT) scan was performed in three cases. This showed characteristic multiple, low attenuation, unenhanced areas within the parenchyma with extension of the inflammatory process into peri-nephric fat (two cases). Ten cases (91%) were of the diffuse type. There was extension into the peri-nephric fat in eight cases (73%). Three cases (27%) were associated with congenital urological abnormalities. Nephrectomy was performed in 10 cases and a partial nephrectomy in one. CONCLUSION: XGP is uncommon in childhood but should always be considered in the differential diagnosis of renal masses, especially in the presence of anaemia. Nephrectomy usually results in a permanent cure.

Adolescent↗
PubMed1994

Phantom pain: natural history and association with rehabilitation.

All 338 lower limb amputees under the care of one disablement services centre were asked to assess phantom pain severity at different times after amputation. Of 212 (63%) replies, 13 had died, 22 were non-limb wearers and 22 were unable to complete the questionnaire. In all, 176 useful replies were received--96 below-knee, 74 above-knee and 6 through-knee. Of these, 98 amputations were performed for trauma and 78 for vascular disease. Below-knee amputees rehabilitated better than above-knee amputees (P < 0.05) and traumatic better than vascular amputees (P < 0.0001). Preoperative pain was worse in vascular amputees (P < 0.0005), but there was no significant difference in the amount of phantom-pain experienced by vascular and traumatic amputees. Phantom sensations were experienced by 82% and phantom pain by 78%. Phantom pain decreased with time, was present equally in traumatic and vascular amputees, and was related to the amount of preoperative pain (P < 0.005). Only 22% felt phantom pain had impaired their rehabilitation. Rehabilitation score was related to phantom pain severity at the time of questionnaire completion (P < 0.05), but not at other specified times after operation.

Adult↗
PubMed1993

Is specialist centre delivery of gastroschisis beneficial?

This study aims to establish the usefulness of delivering neonates with gastroschisis in a regional obstetric and neonatal centre without the facility of on site surgery. A retrospective analysis was performed on the notes of 43 consecutive neonates with gastroschisis referred to Birmingham Children's Hospital over a 10 year period. Two groups were compared: those delivered at the regional obstetric centre (n = 9) and those delivered peripherally (n = 34). Both groups underwent postnatal transfer. There were no significant differences with regard to gestational age, birth weight, caesarean section rate, time to operation, and mortality. Primary closure rates were 89% for the regional centre group and 94% for the peripheral hospital group. Mean time to full enteral feeding was 24 days for the regional centre group and 23 days for those delivered peripherally. These data show that good results can be achieved with postnatal transfer. If on site surgery is not available, neonatal services are adequate peripherally, and the transfer distance is not too great, then delivery in a regional obstetric centre with subsequent postnatal transfer offers no advantage.

Abdominal Muscles↗
PubMed1990

Use of bacteriology in anorectal sepsis as an indicator of anal fistula: experience in a distinct general hospital.

The bacteriology of anorectal sepsis in a district general hospital has been reviewed to see whether the information gained helped patient management. Forty-six patients with anorectal sepsis were reviewed, underlying fistulas were identified in nine patients (19.5%). Bacteroides species were not routinely subtyped in the department. It was found that isolation of unspecified Bacteroides species was not helpful in identifying those patients with underlying fistulas. Unless subtyping of Bacteroides species is specifically requested, pus from anorectal sepsis should not routinely be sent for bacteriology.

Abscess↗
PubMed1987

Amino acid sequence of atrial natriuretic peptides in human coronary sinus plasma.

Two atrial natriuretic peptides were purified from pooled human coronary sinus plasma by Sep-Pak extraction, immunoaffinity chromatography and reverse phase HPLC. The amino acid sequences of the two peptides were homologous with 99-126 human atrial natriuretic peptide (hANP) and 106-126 hANP, the latter being most probably linked to 99-105 ANP by the disulphide bond. The molar ratio of the peptides in plasma, as assessed by radioimmunoassay was 10:3.

Amino Acid Sequence↗
PubMed1986

Haemodynamic and hormonal responses to exercise: studies in patients with diabetes mellitus and adrenomedullary deficiency.

The haemodynamic and hormonal responses of patients with autonomic neuropathy and others with adrenomedullary deficiency were compared with mild hypertensives (range of blood pressure 90-100 mmHg diastolic and 140-160 mmHg systolic) and uncomplicated diabetics during standard exercise and postural manoeuvres using continuous arterial blood pressure monitoring. There was no difference in these parameters between the groups when at rest or on standing. During exercise there was no significant difference in blood pressure and heart rate between the groups and all showed significant increases in plasma noradrenaline (mean rise for all groups 2730-22 105 pm 1(-1), P less than 0.03) and (in all but the adrenalectomized subjects) adrenaline (mean rise for remaining three groups 946-3384 pm 1(-1), P less than 0.03; adrenalectomized group showed no rise). The group with autonomic neuropathy showed a significant rise in plasma cortisol from basal 450 +/- 40 to 845 +/- 72 nm 1(-1), P less than 0.005 after exercise, but the other groups showed no significant change. The maximum level attained for plasma cortisol in the adrenalectomized subjects after exercise was significantly less (260 +/- 41 nm 1(-1) than in the diabetic groups (696 +/- 68 nm 1(-1) (non-neuropaths), 845 +/- 72 nm 1(-1) (neuropaths), P less than 0.01). We have demonstrated normal blood pressure and pulse responses to posture and sustained exercise in diabetics with autonomic neutropathy. The findings of similarly normal responses in patients with adrenomedullary deficiency suggest that circulating adrenaline is not obligatory to a normal haemodynamic response to exercise.

Adrenal Insufficiency↗
PubMedDate not supplied

Solid-phase extraction and optimized separation of doxorubicin, epirubicin and their metabolites using reversed-phase high-performance liquid chromatography.

A reversed-phase isocratic high-performance liquid chromatographic method is described in which a formal structured procedure was applied to predict the mobile phase composition giving optimal baseline resolution of the clinically important anticancer agents doxorubicin and 4'-epidoxorubicin (epirubicin), their principal metabolites, and daunorubicin (internal standard). These formal statistical procedures included the simultaneous techniques of solvent selectivity triangle and factorial design for range-finding preliminary studies, followed by use of the modified simplex, a sequential procedure. These were used to select the parameters of organic modifier, buffer strength and pH necessary for use with a Spherisorb ODS 1 column, to achieve optimal separation of eight anthracycline solutes. Ultraviolet and fluorescence detection was used (lambda ex = 254 nm, lambda em = 560 nm), and the latter gave a low detection limit for doxorubicin in serum of 1 ng ml-1. The optimal mobile phase composition was determined to be acetonitrile-0.06 M Na2 HPO4 containing 0.05% (v/v) triethylamine adjusted to pH 4.6 with 0.03 M citric acid (35:65, v/v). A solid-phase extraction method was developed to enable the selective isolation of anthracyclines by adsorption onto C8 Bond-Elut cartridges, and is based on extraction of serum spiked with a mixture of the anthracycline solutes. The anthracyclines were eluted using acetonitrile-0.2 M Na2 HPO4 containing 0.05% (v/v) triethylamine adjusted to pH 3.6 with 0.1 M citric acid (67.5:32.5, v/v). Reproducible recoveries for doxorubicin (94 +/- 8%) and for epirubicin (96 +/- 8%) were obtained (n = 5). In particular, recoveries for the 7-deoxyaglycone metabolite (99%) were higher than other extraction methods cited.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMedDate not supplied

Atrial and brain natriuretic peptide response to exercise in patients with ischaemic heart disease.

1. The response of venous plasma natriuretic peptides (atrial natriuretic peptide, ANP, and brain natriuretic peptide, BNP) plasma cyclic guanosine monophosphate (cGMP) and vasoactive hormones to dynamic exercise has been studied in 16 subjects undergoing diagnostic exercise tolerance for ischaemic heart disease (IHD), and in five healthy control subjects. 2. In patients with IHD, plasma ANP increased 3-fold (mean 16 +/- 2.5 pmol/L pre-exercise, 51 +/- 11 pmol/L after exercise, P < 0.01). Increase in plasma BNP (10.5 +/- 1.6 pmol/L pre-exercise, 13 +/- 2 pmol/L after exercise, P < 0.01) was proportionately much less than ANP but more sustained. In exercising normal subjects, plasma ANP levels doubled (P < 0.01) but there was no significant change in plasma BNP levels. 3. In patients with IHD, there was a significant correlation between levels of plasma ANP and BNP before exercise (r = 0.97, P < 0.001) as well as during exercise (r = 0.79, P < 0.001). 4. Hormone responses in patients with positive exercise tests did not differ significantly from those with negative tests. 5. Although resting levels of plasma ANP and BNP in IHD are correlated, the findings indicate different mechanisms of secretion. The low BNP/ANP ratio in response to acute dynamic exercise presumably reflects the predominance of ANP in pre-secretory atrial stores.

Aged↗
PubMedDate not supplied

Sexual behavior, knowledge, and attitudes about AIDS among college freshmen.

We surveyed 158 college freshmen on an urban campus to determine their sexual practices and their knowledge and attitudes about acquired immunodeficiency syndrome (AIDS). Many students (47%) were heterosexually active; 1% were homosexual, 1% were bisexual, and 51% had not been sexually active. Among the 77 sexually active students, many engaged in activities that can facilitate transmission of human immunodeficiency virus (HIV): 58% did not always use condoms with a new partner; 31% had had two or more sex partners in the last year; 8% engaged in anonymous sex; and 14% of sexually active women had anal intercourse. Although most sexually active students said they would use condoms more or reduce the number of their sexual partners if they believed these changes would reduce "my risk for getting AIDS," few students had adopted these safer sexual practices. Safer sexual practices were associated with heightened personal concerns about AIDS but not with knowledge, which was at a high level. These findings underscore the need for preventive programs that overcome the gap between knowledge and safer sexual behaviors in this and similar groups of adolescents and suggest that programs that heighten personal concerns may be most effective. Community-based physicians who care for adolescents should develop such preventive programs and integrate them into their practices.

Acquired Immunodeficiency Syndrome↗