Controlled trial of long term oral potassium supplements in patients with mild hypertension

A 15 week randomised double blind placebo controlled trial of oral potassium supplements (48 mmol daily) was conducted in 37 patients who had mildly increased blood pressure and a normal dietary intake of sodium. After a two month run in and a one week baseline period the patients were randomly assigned to receive either potassium supplements (n = 18) or placebo (n = 19). By the third week of treatment blood pressure in the actively treated group had decreased significantly compared with that in the placebo group, though the decrease reached its maximum after 15 weeks. Urinary potassium excretion increased significantly in the group who received potassium supplements, but no significant changes were found in plasma sodium and potassium concentrations or in urinary sodium excretion. In a subgroup of 13 patients who underwent a further nine weeks of treatment with oral potassium supplements at half of the previous dose (24 mmol daily) their blood pressure, at the end of this second study period, was still significantly lower compared with their baseline value but not with that of the placebo group. These results show that moderate oral potassium supplements are associated with a long term reduction in blood pressure in patients who have mild hypertension.     

Minimum oxygen requirements during anaesthesia with the Triservice anaesthetic apparatus A study of drawover anaesthesia in the young adult

Thirty-six servicemen were anaesthetised using the Triservice anaesthetic apparatus. They were allocated randomly into one of two groups, to breathe spontaneously or to receive artificial ventilation, and into subgroups who were given air alone, or air supplemented with 1 or 4 litres/minute of oxygen. A further 12 subjects were studied subsequently using 0.5 litres/minute of added oxygen. Intra-operative blood gases were compared with those of awake premedicated controls. Artificial ventilation was associated with an unchanged arterial oxygen tension with air alone; in the other subgroups arterial oxygen tension was higher than with spontaneous respiration when related to inspired oxygen fraction (p less than 0.05). Air anaesthesia caused significant hypoxaemia with spontaneous ventilation (p less than 0.05), and 50% of the subjects required assisted ventilation. There was also a significant respiratory acidosis (p less than 0.05). Intermittent positive pressure ventilation is the method of choice for field anaesthesia when oxygen is unavailable. Spontaneous respiration must be supplemented with at least 0.5 litres minute of oxygen.     

Phenelzine poisoning

A 46-year-old female with severe phenelzine poisoning was managed successfully by alpha blockade and fluid loading, with the aid of invasive haemodynamic monitoring. The pathophysiology was documented, showing elevated plasma and urinary catecholamines, cardiovascular abnormalities and a contracted blood volume. Most of these changes were reversed following treatment.     

Structural and ultrastructural study of the ovary in childhood leukemia after successful treatment

Ovarian biopsy specimens from ten girls (three postmenarcheal) who had undergone antiblastic treatment for acute lymphoblastic leukemia (ALL) and were in complete remission were examined by light microscope. The biopsy specimens from four of these patients (three postmenarcheal) were also observed by electron microscope. The structural and ultrastructural analysis showed a reduction in the number of follicles which were otherwise normal. No follicles were found in the thin sections from two of the three postmenarcheal girls, whereas normal follicles were observed in the third. The cortical stroma showed moderate to severe signs of fibrosis and changes of capillaries. All of these alterations were more evident in patients where ALL was diagnosed at an older age and this finding suggests that they are at a higher risk for low fertility or early menopause.     

Ovarian Ectopic Pregnancy—A Diagnostic Dilemma

A recent case of ovarian pregnancy, the diagnosis of which is often retrospective, is presented. The discussion is based on current literature concerning the diagnostic difficulties associated with this condition.     

Papaveretum infusions in infants under 6 months of age

The effectiveness of a continuous low dose papaveretum infusion for the relief of postoperative pain was assessed in 29 infants aged 1-6 months nursed on the infant surgical ward following major abdominal surgery. Trained nursing staff were able to adjust the dosage within prescribed guidelines and satisfactory analgesia was obtained with a regimen which delivered up to 0.0375 mg/kg/hour, approximately half the dose recommended in children older than 12 months. There was one case of clinically significant respiratory depression.     

Perceived stress in medical school: Resistors, persistors, adaptors and maladaptors

A longitudinal study of perceived medical student stress (PMSS) was conducted on 305 first year medical students. Data were collected at orientation in September and again in May, 2 weeks before exams. Four types of students were identified using a standardized and reliable measure of PMSS. These included students whose PMSS scores began and ended low (resistors), whose PMSS scores began and remained high (persistors), whose PMSS scores decreased from high to low (adaptors) and whose PMSS scores increased from low to high (maladaptors). The four groups differed predictably on indices of distress and were also distinguishable by a variety of psychosocial variables including type A personality, anger expression and coping. In contrast, life events played a minor role in distinguishing the groups. The results are discussed in relation to previous research on medical student stress.     

Success and limitations of a naked plasmid transfection protocol for keratinocyte growth factor-1 to enhance cutaneous wound healing

Our group and others have previously reported enhancement of cutaneous wound healing following the transfection of tissue with plasmid vectors expressing the DNA for growth factors. In these experiments, growth factor treated animals were usually compared to animals treated with control plasmid vector. To achieve consistent transfection, high DNA plasmid load and repeated penetrations of the wound by needle or gene gun were required. In the current experiments, we assessed the effect of the plasmid load and repeated tissue penetrations on wound healing of excisional wounds in diabetic C57 mice. Animals received 5 mm excisional wounds, and were assigned to the following groups, no treatment, phosphate buffered saline solution injections, and plasmid vector injection with and without the keratinocyte growth factor-1 gene. Intradermal injections of 100 microg plasmid were given adjacent to the wounds at days 1-5, 7 and 11. At day 9, wound closure was more advanced in keratinocyte growth factor-1 treated animals compared to those treated with control plasmid. But a detrimental effect of the DNA plasmid injection was evident from a comparison of the DNA control group versus the non-injected group. Therefore, the challenge for developing an effective system for the enhancement of wound healing lies in improving transfection efficiency.