Etoposide protein binding in cancer patients

The protein binding of etoposide was studied in vivo in 36 cancer patients receiving etoposide therapy. Free etoposide was separated from plasma using an ultrafiltration method and the etoposide concentrations (free and total) were measured by high-performance liquid chromatography (HPLC). Considerable interpatient variation in the protein binding of etoposide was observed. The protein binding of etoposide varied from 80% to 97% (mean, 93%). Univariate analysis showed a significant inverse correlation between the free fraction of etoposide and serum albumin (r = 0.74), daily dose (r = 0.37) and age (r = -0.34). Multivariate analysis demonstrated that serum albumin and age were independent predictors of the etoposide free fraction. Serum bilirubin showed no correlation with etoposide protein binding. There is wide variation in etoposide protein binding in cancer patients, which is mostly dependent on serum albumin concentration.

Effects on health of a change from a delaying to an advancing shift system

OBJECTIVES

Shift work can lead to a range of problems for some people that seem to result from the disturbance of the circadian system, and can broadly be classified as: disturbances of sleep, impaired physical and psychological health, and disturbed social and domestic life. The main attempt to try to reduce these problems has focused on the design of the shift system, and the identification of the most problematic features of the shift system. One such feature is believed to be the direction of shift rotation. Systems that advance are thought to be more problematic than those that delay. The present study examines the change in the direction of shift rotation from a delaying to an advancing system on health and wellbeing.

METHODS

Self reported measures of tolerance to shift work were taken two months before and six months after the change. These included sleep difficulties, gastrointestinal problems, psychological ill health, chronic fatigue, social and domestic disruption, job satisfaction, and satisfaction with the shift system.

RESULTS

The change from a delaying to an advancing system resulted in an increase in sleep difficulties between successive afternoon shifts, but a decrease in social disruption. There was little evidence of impaired health on the advancing compared with the delaying system.

CONCLUSIONS

The increase in sleep difficulties was thought to result from the undesired adaptation of the circadian system to night work, as a result of the afternoon shifts now following a series of night shifts, whereas previously they followed a series of morning shifts. The decrease in social disruption was thought to result from the specific sequence of the shifts and the discontinuous nature of the shift system, in particular, the long week-end off every third week. Lack of reported health related differences are explained in terms of the relatively unharmful nature of the shift system in question, and the relatively short time span over which the study was conducted.

Increased injuries on night shift

Concern over safety has resulted in legislation by, for example, the Commission of the European Union, to limit the number of hours worked at night. There is, however, no direct evidence that injuries are more frequent at night. We analysed all 4645 injury incidents reported for a year on a rotating three-shift system in a large engineering company where the a-priori accident risk appeared to be constant. The relative risk of sustaining an injury was 1.23 (95% CI 1.14-1.31) higher on the night shift than on the morning shift, which showed the lowest incidence. The type of work (machine versus self-paced) affected the pattern and nature of injuries; for self-paced work the relative risk of more serious injury on the night shift compared with the morning shift was 1.82 (1.30-2.34).

Sickness absence in diabetic employees at a large engineering factory

It is not known whether employees who have diabetes mellitus lose more time from work due to sickness than non-diabetic employees. A study was undertaken to compare sickness absence in 91 diabetic with 91 non-diabetic employees matched for sex, age, and occupation. Although sickness absence was greater in the diabetic group this was not significant. Mean sickness absence for the diabetic employees and controls was 32 v 20 days/year (95% confidence interval -5 to 29 days). Because of the large variability in sickness absence in both diabetic and non-diabetic employees, a study of this size is probably not sufficiently powerful to detect a difference.

A phase I/II trial of recombinant human granulocyte-macrophage colony-stimulating factor in the intensification of cisplatin and cyclophosphamide chemotherapy for advanced ovarian cancer

A pilot study was undertaken in eight patients to assess the feasibility of recombinant human granulocyte-macrophage colony-stimulating factor (rH GM-CSF) support to intensify standard chemotherapy for advanced ovarian cancer using a shortened 15 day treatment interval. Only four patients completed the course of six cycles of cisplatin 75 mg m-2 and cyclophosphamide 750 mg m-2 with rH GM-CSF, 3-5 micrograms kg-1 day-1, days 3-14, but one of these suffered a toxic death on study. Another died of disease progression. There were two episodes of life-threatening infection (WHO grade 4), and three patients were withdrawn because of various rH GM-CSF-related problems. Although potentially affording some patients the hypothetical benefits of dose intensification, as well as the possible attraction of a shorter duration of chemotherapy, this regimen is not without problems.

Hepatic arterial chemotherapy for metastatic colorectal carcinoma

In this review, the rationale of regional chemotherapy for treatment of hepatic metastases in advanced colorectal carcinoma is discussed. Pharmacokinetic principles and early clinical experience of hepatic arterial drug administration are summarised. The regional advantage of fluoropyrimidine compounds in this setting is well established, and recent evidence suggests that 5-fluorouracil (5-FU) is more efficacious than the analogue 5-fluoro-2'-deoxyuridine (FUDR). However, while significantly higher clinical response rates can be achieved with hepatic arterial infusion (HAI) chemotherapy compared with conventional intravenous drug administration, patient survival benefit is not significantly different. Several novel approaches to overcome the limitations of HAI therapy are currently being explored. These include concomitant use of biodegradable microspheres, which both slow tumour blood flow and enhance tumour drug uptake, and use of vasoactive agents to redistribute arterial blood flow towards tumours. In addition, novel chemotherapeutic agents which exploit unique biological characteristics of hepatic tumours are entering clinical trial.

Seamstress's finger

Images

Effects of a change in shift work on health

Aspects of health were studied in a sample of factory workers who changed their pattern of working from 'fortnight about' to three advancing shifts. Within the same factory and doing similar work there was a comparison group who were working permanent days only. The change in shifts was associated with more difficulty with sleep, more indigestion, higher alcohol consumption, reduced alertness and a worse social life. There was more minor psychiatric disturbance in those who worked three shifts than in those who worked days only.

Fusion of Rous-sarcoma-virus-transformed rat cells to morphologically normal human or rat cells results in transcriptional suppression of the provirus that depends on its chromosomal integration site

The fusion of a Rous sarcoma virus (RSV)-transformed rat fibroblast clone to at least 2 different human cell types reproducibly produces phenotypically normal hybrids. Analysis of such hybrids reveals that proviral silence is the result of transcriptional down-regulation, presumably by a trans-acting human molecule. Furthermore, this phenomenon seems to be strongly influenced by the proviral chromosomal integration site and its imposition may entail a mechanism that is required only transiently.

Rhodanese isozymes in three subjects with Leber's optic neuropathy

Previous studies have reported an association between Leber's optic neuropathy and deficiency of rhodanese activity in liver and rectal mucosa. We have studied the rhodanese isozymes in liver biopsies from three subjects with Leber's optic neuropathy. The rhodanese isozyme patterns were indistinguishable from controls both in relative intensity and position on the isoelectric focusing pH gradient. No new rhodanese isozymes were observed and there was no evidence of deficiency in any of the cases.

Inhibition of vasopressin secretion during migraine

Six subjects with a history of increased urinary frequency during migraine were studied. In each case there was a marked diuresis and natriuresis within 12 hours of onset of the headache. This was associated with a significant fall in urinary arginine vasopressin (AVP) (p less than 0.01). Migraine may be associated with altered hypothalamic activity resulting in reduced AVP secretion.

Neuroendocrine control of vasopressin secretion and its effect on blood pressure in subjects with spinal cord transection

The osmotic and cardiovascular control of arginine vasopressin (AVP) secretion, and the effect of this hormone on cardiovascular regulation were assessed both in normal controls and in subjects with tetraplegia. Infusion of hypertonic saline caused a marked rise in blood pressure in the tetraplegics but not in the normal controls. Head-up tilt resulted in a greater AVP response in the tetraplegics than in the controls because of the additional hypotensive response in the tetraplegics. Infusion of AVP itself at physiological concentrations had little effect on blood pressure in the normal subjects but resulted in a marked rise in blood pressure in the tetraplegics. Tetraplegics therefore show appropriate release of AVP to both osmotic and cardiovascular stimuli but increased sensitivity to the pressor effects of this hormone.

Amaurosis fugax under the age of 40 years

Sixteen patients who presented under the age of 40 years with amaurosis fugax have been studied. Follow up from the time of presentation was one to 13 years with a median of 3 years. One patient whose attacks of uniocular visual loss were associated with headache developed a permanent uniocular field defect. None of the other patients has suffered permanent visual loss, or had symptoms of cerebral or myocardial ischaemia. All angiograms were normal and it is suggested that carotid angiography is unnecessary in this age group. Four out of ten patients studied demonstrated evidence of platelet hyperaggregability to low concentrations of arachidonic acid and adenosine diphosphate with spontaneous aggregation. However, in six patients treated with aspirin, including three with previous platelet hyperaggregability, there was no change in the frequency of their attacks implying that the observed platelet abnormalities were not the cause of the amaurosis fugax.

Atrial natriuretic factor inhibits the stimulated in-vivo and in-vitro release of vasopressin and oxytocin in the rat

The effect of an atrial natriuretic peptide on the secretion of the neurohypophysial peptides arginine vasopressin (AVP) and oxytocin has been studied in vivo and in vitro. Atriopeptin III was administered intracerebroventricularly to conscious rats and plasma concentrations of AVP and oxytocin were determined both in controls and in rats which had their drinking water replaced by 2% NaCl. The release of both AVP and oxytocin was inhibited when basal levels were increased by the saline treatment. The inhibition of AVP release lasted for 40 min whereas oxytocin release was inhibited for 10 min only. In a further experiment the stimulated release of AVP and oxytocin from the isolated neurointermediate lobe of the rat was also inhibited by atriopeptin III.

Fatigue during the first trimester of pregnancy

Fatigue is accepted as an early symptom of pregnancy. Fatigue may be due to energy depletion resulting from the physiologic and psychological changes occurring during the first trimester. The following changes are considered: oxygen consumption; fetal growth and development; cardiovascular, respiratory, urinary tract, metabolic, and psychological processes. The goals of nursing therapy for first-trimester fatigue are to help the woman cope with the distress caused by the fatigue and to help minimize or alleviate the fatigue to the degree that is possible. The nursing therapy should include sharing information about the nature of the fatigue, developing an activity-rest program, and sharing information aimed at alleviation of psychological stresses.

Migraine

Classic migraine appears to be due to a primary focal change in cerebral neuronal metabolism associated with a spreading reduction in cerebral blood flow. Abnormalities of platelets and certain vasoactive amines have been found but we are still a long way from understanding the pathogenesis of migraine.

Deficiency of thiosulphate sulphurtransferase (rhodanese) in Leber's hereditary optic neuropathy

Leber's hereditary optic neuropathy is a rare cause of progressive visual failure. Its cause is unknown, but one hypothesis is that patients have a defect in the detoxication of cyanide. One of the enzymes used in this detoxication is thiosulphate sulphurtransferase (rhodanese). The activity of this enzyme was measured in the rectal mucosa of a group of subjects with Leber's hereditary optic neuropathy, and it was found to be considerably reduced compared with that in a group of controls (p less than 0.001). This finding supports the hypothesis of an inborn error of cyanide detoxication in this condition.

Mortality and stroke after amaurosis fugax

One hundred and ten patients who had presented with amaurosis fugax and were treated medically were studied retrospectively. Follow up from the time of presentation was six to nineteen years with a median of eight years. The mortality and frequency of strokes in this group was compared with populations matched for age and sex. Life expectancy in patients with amaurosis fugax was reduced. Ischaemic heart disease was the most frequent cause of death and occurred at a greater rate than in the general population (p less than 0.01). The indicence of stroke was higher than in the Oxfordshire Community Stroke Project 1981-1983 (p less than 0.01). Comparing our results to those published for cerebral transient ischaemic attacks, patients with amaurosis fugax have a similar mortality rate but probably have a lower incidence of stroke. Patients with amaurosis fugax who have an occluded or narrowed proximal internal carotid artery have a greater risk of subsequent stroke than those with a normal carotid artery, or an arteriogram (p less than 0.01).

Cefuroxime pharmacokinetics in continuous and intermittent peritoneal dialysis

Pharmacokinetics of cefuroxime was studied in patients on continuous ambulatory or intermittent peritoneal dialysis. A single intravenous bolus (15 mg/kg) of cefuroxime provided a mean serum concentration of 86 mg/litre 5 min, 40 mg/litre 1 h, 163 mg/litre 24 h after the injection. The peritoneal clearance of cefuroxime varied widely among different individuals, ranging from 1.45 to 6.17 ml/min with a mean of 3.59 ml/min during 4-hour exchanges, and from 0,52 to 11.3 ml/min during 2-hour exchanges. A single injection (15 mg/kg) of the antibiotic could not provide satisfactory antibiotic concentrations in peritoneal effluent during peritoneal lavage. When cefuroxime had been added to peritoneal dialysis solution before the solution was instilled into the peritoneal cavity, a significant decrease in cefuroxime concentration occurred in the peritoneal effluent even after a short equilibration time. Furthermore, cefuroxime concentrations measured in residual dialysis solutions in the plastic bags ranged from 44.3 to 1,351% of the concentration of cefuroxime calculated from the added doses, indicating that despite great care, mixing of the antibiotic with dialysis solutions in plastic bags was far from uniform.

Myelopathy secondary to metastatic carcinoid tumour

Images

Argyll Robertson pupils due to neurosarcoidosis: evidence for site of lesion

Images

Mothers of adolesent mothers

The attitude of forty-four mothers of adolescent mothers (MAM) were assessed by interview and questionnaire. Most adolescent mothers (AM) and their infants lived with MAM. Thirty-two percent of MAM and sisters of AM had themselves experienced a pregnancy prior to seventeen years of age. The majority of MAM expressed positive feelings about AM and their infants. MAM reported little change in their own life style as a result of their daughter's pregnancy. Most MAM's provided child care and financial assistance for AM, but reported that the AM had primary child care responsibility for the infant.

Neonatal circumcision

The American Academy of Pediatrics has stated that there is no valid medical reason for performing routine neonatal circumcision. Although the issue is hotly debated in medical circles, little attention has been given to the issue in the nursing literature. It is important that nurses understand the medical, social, religious, and child care issues involved in order to help parents make informed decisions regarding circumcision of their neonate.