Monovalent cation composition and ATP and lipid content of irreversibly sickled cells

Discontinuous Stractan gradients were used to separate heterogeneous populations of sickle cells into discrete subpopulations containing varying proportions of reticulocytes, mature discoid cells, and irreversibly sickled cells (ISC). The improved homogeneity of these preparations, together with an enhanced yield of ISC, allowed us to distinguish effects of cell maturation from those of irreversible sickling. With these cell preparations we have begun to define physical properties of ISC. We confirmed the marked abnormalities in cation composition of native ISC. Measurements of ATP in ISC did not substantiate prior reports of ATP deficits. Finally, no evidence for substantial loss of membrane lipids during the process of ISC formation could be demonstrated.     

SPONTANEOUS REGRESSION OF CANCER OR MISDIAGNOSIS? FOUR CASE REPORTS

Four case reports regarding possible spontaneous regression of cancer are given. This is a rare but previously documented occurrence, with the literature suggesting possible causal factors for cancer regression or an indefinite period of dormancy. These include genetic, hormonal, immunological and psychological factors. However, the literature makes no reference to potential misdiagnosis, either clinically or histologically. The effect of being diagnosed as having terminal cancer is profound and even after regression or resolution of the disease, there are inevitable psychological sequelae.     

Prolonged inhibition of presynaptic catecholamine synthesis does not alter leptin secretion in normal-weight men and women

Leptin has been called a hormone of reproduction, and seems to link fat and fertility. It has been speculated that the neurotransmitter norepinephrine (NE) (noradrenaline), possibly via the sympathetic nervous system, may represent the afferent signal which modulates leptin release from adipocytes. The purpose of this study was to produce a state of decreased sympathetic output by using the catecholamine synthesis inhibitor alpha-methyl-para-tyrosine (AMPT), in order to study the effect of this compound on the secretion of leptin from fat cells. Ten subjects (five women and five men) received a total of 5 x 1 g doses of AMPT or 5 x 50 mg promethazine (active placebo) over a 26 h period, separated by 4-6 weeks using a randomized, double- blind, placebo-controlled, cross-over design. Blood samples for hormone measurements were obtained over 24 h (18 time points) on day 2 of each experiment. Urinary measurement of the NE metabolite 3-methoxy-4- hydroxyphenylglycol (MHPG) on study day 2 served as a marker of the effectiveness of AMPT as an inhibitor of NE synthesis. The daily excretion of this metabolite decreased from 1.56 +/- 0.22 mg in the placebo experiment to 0.53 +/- 0.1 mg in the active experiment (P < 0.05). Plasma leptin concentrations measured in the control group in women and men were similar to those reported previously in lean subjects with a body mass index < 27.5 kg/m2. Leptin concentrations in women were 3-fold higher than in men. Leptin is secreted in a circadian rhythm in both sexes with an increase of nocturnal concentrations by approximately 50%. Two-way analysis of variance reveals no significant difference in leptin secretion between the control and active groups in women and men. In summary, preliminary results do not support the hypothesis that NE represents the afferent signal from the central nervous system which modulates leptin release from adipocytes in the human. Further studies are needed to define the role of the sympathetic nervous system as well as NE in the regulation of leptin secretion and its involvement in obesity and reproduction.      

Prevalence of very severe headache in a large US metropolitan area

Reliable data regarding prevalence of headache, in general, and migraine, in particular, remain elusive. Methodological inconsistencies and inadequacies are largely responsible. The present study uses a random sampling technique to assess the prevalence of very severe headache. Estimates of headache prevalence were obtained for two time periods: indeterminate/lifetime and the past three months. The resulting prevalence estimates were 20.4 and 15.2%, respectively, for women, and 11.2 and 8.8%, respectively, for men. The estimates are compared with those of previous studies. The present study is compared with these previous studies and suggestions are offered for future research. Aspects of the treatment experience of respondents with poorly controlled headache are also addressed.     

Maternally acquired immunity in newborns from women infected by the human immunodeficiency virus

Maternally acquired immunity was studied in 16 pairs of human immunodeficiency virus (H1V)-seropositive women and their newborns, and was compared to 18 control mother-newborn pairs. The HIV-infected women had higher IgG levels than the control subjects, but no difference was observed between newborn samples, presumably due to the limited placental IgC transfer in the HIV group. A poor type 2 poliovirus antibody transfer was also noted in this group. The population of newborns lacking demonstrable measles antibodies was higher in the HIV group than in the control group, probably because many of the HIV-infected mothers lacked measles antibodies also. These results show that maternally acquired immunity may be affected to newborns from HIV-infected women, either because of low maternal serum antibody levels or deficient transplacental transfer. If so, the measles vaccine schedule should be revised for these children and the same should be done for future passive immunization regarding fetus protection in pregnant HIV-seropositive women.     

Bronchial artery embolization to control hemoptysis in cystic fibrosis

Severe hemoptysis in cystic fibrosis can be life-threatening because of acute blood loss or because it interferes with sustaining physical therapy of the chest. Hemoptysis was controlled in 19 of 20 cystic fibrosis patients by means of embolization with a combination of 250-590-microns particles of polyvinyl alcohol foam and absorbable gelatin pledgets. Repeat embolization was needed in eight patients to achieve or maintain effective hemostasis. One or more aberrant bronchial arteries were found in seven patients (35%), and a spinal artery branching from a vessel that also supplied bronchial circulation was present in 11 patients (55%). The data suggest that although embolization has a wider applicability than previously reported, care should be taken during angiography to evaluate the bronchial circulation because aberrant bronchial vessels and spinal arteries arising from bronchial circulation are common.