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L Fall

Publications and source records attributed to L Fall.

25 records · Page 2Linked to original sources
PubMed1978

Aggregation effects on oxygen binding of sickle cell hemoglobin.

Deoxygenation of concentrated solutions (0.33 gram per milliliter) of sickle cell hemoglobin show (i) a "crisis point" where the oxygen binding curve is unusually steep (Hill coefficient of 5 to 6), and (ii) a simultaneous increase in light scattering. Nearly identical oxygen binding curves are obtained upon oxygenation and deoxygenation of these solutions. The influence of aggregation is to shift the curve toward higher pressures.

Allosteric Regulation↗
PubMed1971

Adenylate energy charge in Escherichia coli during growth and starvation.

The value of the adenylate energy charge, [(adenosine triphosphate) + (1/2) (adenosine diphosphate)]/[(adenosine triphosphate) + (adenosine diphosphate) + (adenosine monophosphate)], in Escherichia coli cells during growth is about 0.8. During the stationary phase after cessation of growth, or during starvation in carbon-limited cultures, the energy charge declines slowly to a value of about 0.5, and then falls more rapidly. During the slow decline in energy charge, all the cells are capable of forming colonies, but a rapid fall in viability coincides with the steep drop in energy charge. These results suggest that growth can occur only at energy charge values above about 0.8, that viability is maintained at values between 0.8 and 0.5, and that cells die at values below 0.5. Tabulation of adenylate concentrations previously reported for various organisms and tissues supports the prediction, based on enzyme kinetic observations in vitro, that the energy charge is stabilized near 0.85 in intact metabolizing cells of a wide variety of types.

Adenine Nucleotides↗
PubMedDate not supplied

[Clinical characteristics of primary hypothyroidism in Dakar. Apropos of 37 cases].

Primary hypothyroidism, other than cases of endemic goiter, has rarely been described in Africa. We conducted a retrospective study of the patients admitted to our hospital unit between 1985 and 1996. The inclusion criteria were clinical signs of hypothyroidism and low levels of thyroid-stimulating hormone. We investigated socio-demographic, clinical (hypometabolic syndrome, cutaneomucal syndrome, muscular syndrome) and etiological (spontaneous thyroid atrophy, thyroidectomy, multinodular goiter) factors. Overall, our study population contained 37 cases, 8 men and 29 women. The mean age of the men was 40.8 +/- 19.2 years and that of the women was 41.5 +/- 14.5 years. Eighteen patients (about 50%) lived in the suburbs, 25% of patients were from urban areas and 25% from rural areas. The associated clinical signs were: 1) hypometabolism: constipation (51% of cases), bradycardia (45%), physical asthenia (40%), sleeping during the day (32%), frilosity (35%); 2) cutaneomucal syndrome: hoarseness (48%), alopecia (32%), facial puffiness (27%), macroglossia (24%), hypoacousia (21%), weight gain (18%), dry skin (16%), pallor (2%); 3) muscular syndrome was rare: myalgia (4 cases), muscle weakness (2 cases). Mean total cholesterol concentration was 2.54 +/- 0.75 g/l; mean total T3 was 1.027 +/- 0.84 nmol/l; mean total T4 was 16.70 +/- 16.89 nmol/l; mean TSH concentration, measured by radiometry, was 63.74 +/- 51.01 mIU/l. The etiology was goiter in 13 cases, thyroidectomy (11 cases) and spontaneous thyroid atrophy (13 cases). Thus, primary hypothyroidism does occur in African hospitals, particularly in Senegal. This disease, which has traditionally been reported in public health studies of endemic goiter, also occurs in cosmopolitan African environments.

Adolescent↗