PubMed Health⌕ Search

Biomedical subjects

A E Jones

Publications and source records attributed to A E Jones.

At least 19 recordsLinked to original sources
PubMed1991

Megavoltage pituitary irradiation in the management of prolactinomas: long-term follow-up.

OBJECTIVE To determine the long-term effects of external beam megavoltage radiotherapy (RT: 4500 cGy via three portals at 180 cGy or less total daily dose) on endocrine function in prolactinomas. DESIGN Longitudinal study following radiotherapy with periodic re-assessment at regular intervals, at least 2 months off dopamine agonist therapy. PATIENTS Thirty-six female patients, age range 19-50 years, with either macroprolactinomas (12 patients) or microprolactinomas (24 patients), but without significant suprasellar extensions. MEASUREMENTS Clinical appraisal, and anterior and posterior pituitary assessment: basal levels at yearly intervals or less, with dynamic screening with TRH, LHRH and hypoglycaemic stimulation every 2-3 years. RESULTS Before RT, serum prolactin (PRL) levels ranged from 1150 to 34,000 mU/l; after RT (mean 8.5 years, range 3-14), serum PRL fell to normal (i.e. less than 360 mU/l) in 18 of the 36 patients (50%), and to just above the normal range (378-780 mU/l) in a further 10 (28%). Two patients had PRL levels at their last follow-up higher than those at presentation, with one patient showing evidence of tumour recurrence on CT scan. A total of eight of the 36 patients (23%) developed post-RT gonadal deficiency by the end of follow-up at 8 +/- 3.1 years (+/- SD, range 3-11), but six were aged over 40 years at that time. GH deficiency was frequent, occurring in 94% of patients, usually from 2 to 3 years post-RT, while TSH deficiency and reduced ACTH reserve was uncommon (each 14%), and occurred later. In the subgroup of 12 patients with macroprolactinomas, results were broadly comparable. CONCLUSIONS Megavoltage RT produces a progressive fall in serum prolactin in the great majority of patients with prolactinomas, with a relatively low incidence of TSH or ACTH deficiency. As it is now clear that dopamine agonist therapy alone provides sufficient management for microprolactinomas, RT may be used for the long-term control of macroprolactinomas, together with interim dopamine agonist therapy. It allows pregnancy to be safely undertaken but, in view of the delayed onset of gonadal deficiency, its administration should be timed with respect to the desired onset of conception in women.

Adrenocorticotropic Hormone↗
PubMed1990

Pharmacokinetics of intravenous amoxycillin and potassium clavulanate in seriously ill children.

The pharmacokinetics of amoxycillin and potassium clavulanate were studied in 15 sick children after a 30 min iv infusion of 50 mg/kg amoxycillin and 5 mg/kg clavulanic acid as the potassium salt. Levels of both compounds in plasma were assayed microbiologically. Mean peak concentrations at the end of the infusion were 121.0 mg/l of amoxycillin and 12.0 mg/l of clavulanate, falling to a mean of 15.8 and 1.92 mg/l respectively after 2 h. Mean beta phase T 1/2 was 0.88 h for amoxycillin and 0.79 h for clavulanate. The elimination half-life of clavulanate in some individuals was much shorter because of higher plasma clearance. The data suggest that the treatment of some infections due to beta-lactamase producing organisms in such severely ill children may require more frequent iv administration of amoxycillin and potassium clavulanate, than in less severely affected children.

Adolescent↗
PubMed1989

Longer-term regulation of pyruvate dehydrogenase kinase in cultured rat hepatocytes.

The activities of pyruvate dehydrogenase (PDH) kinase and of PDH kinase activator protein (KAP) were increased 2-2.4-fold during 25 h of culture of hepatocytes from fed rats with glucagon plus n-octanoate. PDH kinase activity in hepatocytes from starved rats (initially 2.2 x fed control) fell during 25 h of culture in medium 199 (to 1.5 x fed control), but was maintained by glucagon plus octanoate. Dibutyryl or 8-bromo cyclic AMP increased PDH kinase activity 2-2.2-fold in hepatocytes from fed rats, but phenylephrine and isoproterenol (isoprenaline) were without effect. Insulin blocked the action of glucagon to increase PDH kinase activity and decreased the effect of octanoate and octanoate plus glucagon. It is suggested that the effects of starvation to increase activities of PDH kinase and of KAP in liver are mediated by alterations in circulating concentrations of glucagon, fatty acids and insulin and in hepatic cyclic AMP.

Animals↗
PubMed1989

Durability of immunity to diphtheria, tetanus and poliomyelitis after a three dose immunization schedule completed in the first eight months of life.

Blood samples were obtained from school entrants whose primary immunization schedule had consisted of three doses of DT or DTP vaccine and three doses of OPV all given before the age of 8 months. The sera were separated and assayed for diphtheria antitoxin, tetanus antitoxin and antibodies to the three serotypes of poliovirus. The results of the assays showed that the abbreviated three dose schedule induced satisfactory immunity to all five infections until school entry and that a reinforcing dose at 18 months was unnecessary.

Antibodies, Viral↗
PubMed1989

Megavoltage pituitary irradiation in the management of Cushing's disease and Nelson's syndrome: long-term follow-up.

We report the long-term follow-up of the clinical and biochemical effects of megavoltage pituitary irradiation (radiotherapy; RT), administered as primary or secondary therapy, for pituitary Cushing's disease and Nelson's syndrome in 52 patients. Irradiation was administered, from a 4-15 MeV linear accelerator, via a three-field technique (two lateral, one frontal), to a total dose of 4500 cGy (rad) in 25 fractions over 35 days. Twenty-one patients received RT as primary ablative therapy for Cushing's disease and were under follow-up 5.8 to 15.5 years later (median 9.5 years). All were initially treated with metyrapone to induce normal mean plasma cortisol levels, and all achieved clinical remission on this therapy. At latest follow-up, 12 (57%) are off all therapy, in clinical remission, with a normal mean cortisol through the day; however, only two show completely normal plasma cortisol responses to dynamic testing; four remain on medical therapy with metyrapone or op'DDD and all have required a steady dose reduction accompanied by falling plasma ACTH levels; five have required alternative therapy with bilateral adrenalectomy and/or transsphenoidal hypophysectomy. Fifteen patients received RT for Nelson's syndrome, developing after bilateral adrenalectomy, and have been followed up for 1.5 to 17.3 years (median 9.6 years). Fourteen patients showed progressive depigmentation, shrinkage of the pituitary adenoma and fall in plasma ACTH levels to 1-72% (median 16%) of the pre-RT basal value. In the remaining patient an initial fall in plasma ACTH was followed by tumour enlargement at 6 years, leading to death at 11 years after RT. Of the remaining patients, results are assessed in nine who received RT after unsuccessful transsphenoidal surgery, three after transfrontal surgery for aggressive macroadenomas, and four prophylactically after bilateral adrenalectomy. Radiotherapy remains a valuable second-line therapy for Cushing's disease and its complications.

Adolescent↗
PubMed1989

Specificity of limited range of motion variable resistance training.

The present study evaluated the effect of limited range of motion (ROM) variable resistance training on full ROM strength development. Twenty-eight men and 31 women were randomly assigned to one of the three training groups (A, B, AB) or a control group (C). A, B, and AB performed variable resistance bilateral knee extension exercise 2 (N = 25) or 3 (N = 19) d.wk-1 for 10 wk with an amount of weight that allowed one set of 7-10 repetitions. Group A trained in a ROM limited to 120 degrees to 60 degrees of knee flexion. Group B trained in a ROM limited to 60 degrees to 0 degrees of knee flexion. Group AB trained full ROM. Prior to and immediately following training, isometric knee extension strength was evaluated at 9 degrees, 20 degrees, 35 degrees, 50 degrees, 65 degrees, 80 degrees, 95 degrees, and 110 degrees of knee flexion with a Nautilus knee extension tensiometer. Reliability coefficients for repeated measurements of isometric strength at multiple joint angles were high (r = 0.86-0.95, P less than 0.01; SEE = 23.1-37.2 N.m). Compared to the control group, all training groups improved in isometric strength (P less than 0.01 at each angle tested except for group A at 9 degrees and 20 degrees of knee flexion and group B at 95 degrees of flexion. Isometric strength gains for group AB were similar throughout the full ROM. Isometric strength gains for the limited ROM trained groups were greater in the trained ROM than in the untrained ROM (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Long-term effects of radiotherapy for acromegaly on circulating prolactin.

In 61 acromegalic patients, serum PRL was assessed (off medical treatment) before and 2 to 12 (mean 6.4) years after external beam radiotherapy. Before radiotherapy elevated PRL levels were present in 22 of 35 males (63%) and 12 of 26 females (46%) and were above 1000 mU/l in 11 males and 5 females. When studied for up to 5 years after radiotherapy, 22 of 23 (96%) patients who had not had surgery and who had normal PRL pre-radiotherapy showed an increased PRL level and this was also seen in 17 of 27 (63%) who had been hyperprolactinaemic initially. In contrast, 10 of 27 patients (37%) who had elevated pre-radiotherapy levels (all greater than 1000 mU/l) had a reduction in PRL values after radiotherapy. In all 11 patients who underwent surgery before radiotherapy, an increase in PRL was seen after radiotherapy. In the 21 patients followed for 10-12 years, the peak PRL value occurred 1-6 years after radiotherapy. After this, a progressive reduction of PRL to normal was seen. Normal levels were reached 4 to 10 years after radiotherapy. No correlation was found between pretreatment PRL values and final GH values in the whole group, nor between changes in PRL and the development of impaired ACTH or TSH secretion. Thus, different patterns of PRL behaviour suggest that radiotherapy treatment may either produce hyperprolactinemia from mild hypothalamic damage or ablate PRL secreting cells if they were present in the tumour before treatment. These changes do not predict final GH results or the development of hypopituitarism after radiotherapy.

Acromegaly↗
PubMed1987

Insulin reverses effects of starvation on the activity of pyruvate dehydrogenase kinase in cultured hepatocytes.

In tissue culture of hepatocytes, insulin (0.1-1 munits/ml for 4 h) reversed completely the effects of starvation of rats to decrease the activity of pyruvate dehydrogenase (PDH) complex and to increase the activities of PDH kinase and PDH kinase activator protein. It had no effect in hepatocytes from fed rats. Significant effects of insulin were detected with 0.01 munit/ml after 4 h, and in 1-2 h with 1 munit/ml.

Animals↗
PubMed1986

Follicular lymphoma: prognostic factors for response and survival.

One hundred forty-eight patients with newly diagnosed follicular lymphoma were treated over a 12-year period. Twenty-two patients received radiotherapy for stage I and II disease, followed by adjuvant chemotherapy in 14 patients. One hundred thirteen were treated at presentation with short courses of chemotherapy, most often with single-agent chlorambucil for bulky stage II and stages III and IV disease. Thirteen patients were managed expectantly until there was evidence of disease progression. The median survival was 9 years. Patients treated with radiotherapy for stage I and II disease had an 83% relapse-free survival, but those with bulky stage II or stages III and IV disease treated with chemotherapy pursued a remitting and relapsing course with a 70% response rate at initial and subsequent retreatments, but a median duration of remission of 4 years in stage III and 1 year in stage IV disease (P = .041). Patients were observed in relapse and retreatment was administered as appropriate, once every 33 months on average. Poor prognosis patients could be identified by a combination of the presentation characteristics: B symptoms, hepatosplenomegaly, anemia, and abnormal liver function. These factors predicted a poor response to treatment and correlated with a short survival. Histologic subgroups were not associated with differences in survival, but transformation to a diffuse high-grade lymphoma was observed in 23 of the 72 patients (32%) at risk, with a median follow-up of 6 years and 6 months, and was associated with a very poor prognosis. The present treatment strategy has proved successful for most patients with localized disease and those older patients with indolent small volume disseminated follicular lymphoma. New approaches are being investigated for the younger poor prognosis patients.

Adult↗
PubMed1985

Concomitant conjugal gliomas with similar histologic features.

Conjugal tumors are rarely reported; but nevertheless, raise important questions of possible etiologic factors. In this report, the presentation of grade 2 gemistocytic astrocytomas in an unrelated married couple in their early thirties within 18 months of each other is described. In both cases the left frontal region of the brain was involved and histologically the tumors were very similar. Although there are no accurate figures on the true incidence of gliomas, an estimate can be derived from reliable epidemiologic studies of primary brain tumors as a whole. Using such data, it is calculated that the risk of two designated persons developing a grade 1 to 2 astrocytoma while in the fourth decade within the same year is approximately 1 in 30 billion (10(9)) and, for this couple, over a period of 15 years, at least 1 in 185 million. No specific causative environmental factors were identified in the patients, and results of conventional tests for viral and other infections were negative. It is postulated that apart from remote chance, such conjugal lesions implicate the action of an environmental agent. In the absence of other factors, involvement of a slow, unconventional virus is a possibility that must be strongly considered.

Adult↗
PubMed1985

A new 111In-bleomycin complex for combined radiotherapy and chemotherapy.

Six days after tumor transplantation three daily intraperitoneal doses of 0.9% NaCl, bleomycin (BLM), or a new 111In-bleomycin complex (BLMC, 15 microCi/g body weight) were administered to glioma-bearing mice. After therapy, tumors in mice treated with 111In-BLMC were smaller than those treated with BLM. Sixteen days after the first injection tumor size for 111In-BLMC-treated mice was 560 (240-1,030) mm3, 1,980 (1,400-3,290) mm3 for BLM (P less than 0.025), and 4,830 (2,580-9,180) mm3 for NaCl (0.1 less than P less than 0.2). Thirteen days after tumor transplantation glioma-bearing mice received single intratumor injection of 0.9% NaCl, BLM, or 111In-BLMC (1.5 mCi, carried by 0.5 mg BLM/g tumor weight). The average tumor size for 111In-BLMC was smaller than that for BLM by a factor of 2.5-3.7. Host weights for these two groups were similar, and morphologic abnormalities were not found in kidney or liver.

Animals↗
PubMed1985

A potential microneurosurgical method for the manipulation of the developing nervous system of the postimplantation mouse embryo in utero. I. Injection methods.

A microsurgical method for the injection of cells into the postimplantation mouse embryo whilst it is in utero is described. Specific regions of the 9.5-day-old mouse embryo brain have been injected with marker substances, such regions including the intraventricular cavity of the telencephalon and the trigeminal facialis ganglion bulge of the forebrain. Histological study of the injected embryos shows that the injection method is precise and able to avoid damage to other nearly embryonic tissues. The method should have wide application in the study of questions of normal cell lineage, neoplasia, teratology, and toxicology.

Animals↗
PubMed1985

Glycosylated haemoglobin and glycosylated albumin in non-diabetic and diabetic mothers, and their babies.

Glycosylated haemoglobin (GHb), glycosylated albumin (GAlb), and blood glucose were measured from 283 non-diabetic, 7 insulin-dependent diabetic, and 5 gestational diabetic mothers, and in the cord blood of their babies. Significant correlation was found between mother and baby for GHb (r = 0.31) and GAlb (r = 0.42). However, GHb, GAlb and glucose concentration were significantly higher in maternal blood compared to cord blood (p less than 0.001). Only GAlb showed any difference between a pregnant and a non-pregnant population (p less than 0.001). All three parameters were significantly higher in the diabetic mothers compared to the non-diabetic mothers (p less than 0.001). No difference was found between the levels of GHb and GAlb in babies from these two groups. There was no difference in the level of GHb between gestational and insulin-dependent mothers although the latter showed a significantly higher blood glucose (p less than 0.05).

Adult↗
PubMed1985

Affinity chromatography: a precise method for glycosylated albumin estimation.

A method is described for the estimation, in plasma, of glycosylated albumin, using the commercially available affinity chromatographic material Glycogel B (immobilised m-aminophenylboronic acid on an agarose support) to separate the glycosylated and non-glycosylated albumin, followed by the analysis of albumin concentration using rocket immunoelectrophoresis. Glycosylated albumin and glycosylated haemoglobin showed good correlation (r = 0.91) when both are estimated by affinity chromatography. The glycosylated albumin method displays good within-batch (2.8-4.4% CV) and between-batch (2.9-5.4% CV) precision, and the method is not affected by haemolysis. Using this method a reference range of 2.0-5.4% was found for glycosylated albumin. Levels of glycosylated albumin in diabetics (10.06 +/- 3.23%) were found to be significantly higher (P less than 0.001) than those in non-diabetics (3.72 +/- 0.85%). It was found that loading more than 3 mg of albumin on to a 1 mL affinity column must be avoided, as this appears to overload the column.

Anticoagulants↗
PubMed1984

Growth hormone releasing factor: comparison of two analogues and demonstration of hypothalamic defect in growth hormone release after radiotherapy.

Human pancreatic growth hormone releasing factor (hpGHRF(1-40] stimulates the release of growth hormone in normal subjects and some patients with growth hormone deficiency. A study comparing the shorter chain amidated analogue hpGHRF(1-29) with an equivalent dose of hpGHRF(1-40) in seven normal subjects showed no significant difference in growth hormone response between the two preparations. Six patients with prolactinomas were also tested; these patients had received megavoltage radiotherapy previously but had developed growth hormone deficiency as shown by insulin induced hypoglycaemia. In all six patients 200 micrograms hpGHRF(1-40) or hpGHRF(1-29)NH2 produced an increase in the serum growth hormone concentration. These data suggest that hpGHRF(1-29)NH2 may be useful for testing the readily releasable pool of growth hormone in the pituitary and that cases of hypothalamo-pituitary irradiation resulting in growth hormone deficiency may be due to failure of synthesis or delivery of endogenous GHRF from the hypothalamus to pituitary cells.

Adult↗
PubMed1984

A new 111In-bleomycin complex for tumor imaging: preparation, stability, and distribution in glioma-bearing mice.

A new 111In-bleomycin complex (111In-BLMC) is here reported. Its radiochemical purity was 99% by thin-layer chromatography (TLC) (Rf 0.65) and in 5% agarose gel electrophoresis in 0.02 M NaHCO3 it migrated toward the anode. Autoradiographs of TLC and gel electrophoresis plates showed no change on storage for 3 weeks. Urine and plasma from untreated or glioma-bearing mice after injection of 111In-BLMC were analyzed by TLC and gel electrophoresis. Results indicated stability in vivo, nonbinding to transferrin, affinity to viable tumor, and excretion faster than 111In-BLM-B2, 111In-BLM, or 57Co-BLM. Tissue distributions 24 hr after injection of radiopharmaceutical showed activity ratios of tumor to blood, muscle, and brain of 13.1, 12.4, and 81.6, respectively, which were significantly higher than those for previously prepared 111In-BLM-B2 or 111In-BLM (except for brain, 0.05 less than P less than 0.1). The new 111In-BLM complex may be useful in clinical imaging and for combining radionuclide radiotherapy and chemotherapy.

Animals↗
PubMed1984

A new tumor imaging agent--111In-bleomycin complex. Comparison with 67Ga-citrate and 57Co-bleomycin in tumor-bearing animals.

We have found a new 111In-bleomycin complex (BLMC), which has high affinity to tumor, does not bind to transferrin and is stable in vivo. Distribution in animals bearing glioma, hepatoma, or mammary adenocarcinoma at 48 hours showed: the ratios of tumor to blood, brain, heart, lung, liver, pancreas, stomach, and femur were 1.4-22.4 times as high for 111In-BLMC as for 67Ga-citrate. In mammary adenocarcinoma, 111In-BLMC bound more to viable and 57Co-Bleomycin (BLM) more to necrotic tumor. In viable tumor, the concentration of 111In-BLMC was similar to that of 57Co-BLM. The ratios of tumor to stomach and pancreas were higher, to blood, brain, muscle, heart, and femur were lower for 111In-BLMC than those for 57Co-BLM. The ratios of tumor to lung, liver, spleen, skin, and kidney were similar for the two compounds. Tumors were imaged more distinctly with the new 111In-BLMC and 57Co-BLM than with 67Ga-citrate. 111In-BLMC is promising for tumor imaging.

Animals↗