Cancer risk after evaluation for infertility

To evaluate cancer risk by various causes of infertility, the authors conducted a retrospective cohort study among 2,335 women evaluated for infertility at the Mayo Clinic between 1935 and 1964. Most cancers occurred at expected frequencies, with the exception of cancers of the thyroid (standardized incidence ratio (SIR) = 2.6) and other endocrine glands (SIR = 6.7), although analyses were based on small numbers. Patients with progesterone deficiencies (31 per cent of the study subjects) had a 20 per cent higher cancer risk than did those with other causes of infertility, with excesses deriving primarily from cancers of the lung, cervix, ovary, and thyroid and from melanoma. Breast cancer risk, however, was not elevated in either patients with progesterone deficiencies (SIR = 0.9) or patients with other causes of infertility (SIR = 1.0). Examination of other parameters of infertility, including age at evaluation, type of infertility (primary vs. secondary), and years of attempted conception, showed no elevated risks of breast cancer in any subgroup. These results fail to support previous studies that have linked progesterone deficiencies among infertile women to elevated breast cancer risk. However, the data suggest a possible involvement of a progesterone deficiency in the etiology of other cancers, particularly thyroid cancer and melanoma.     

Relation of olfactory bulb and cortex. II. Model for driving of cortex by bulb

The major projection pathway of the olfactory bulb is by way of the lateral olfactory tract (LOT) to the olfactory cortex. Oscillatory bursts of extracellular potential appear during inspiration in both bulb and cortex. Based on anatomical and physiological considerations, a model was proposed, consisting of a bulbar transmitter, a conduction line representing axons in the LOT, and a cortical receiver. The model predicted the relation between phase and frequency of bulbar and cortical burst pairs, based on the expectation that the bulb drives the cortex. Experimental phase-frequency plots were computed from bursts of 9 bulbocortical electrode site pairs from each of 10 rabbits. For each site pair, the model predicted the expected range of the joint variation of phase and frequency, using the known distance between the bulbar and cortical sites. The model was highly successful (greater than 95% prediction accuracy) for one quarter of the total number of site pairs examined. The wide range of variation for the rest of the data suggested that higher order interactions are responsible for the phase relation between bulb and cortex. Convergence of input, independence of the cortical generator, cortical feedback to the bulb and synchronization by an outside source are all discussed as possible contributors to this variation.     

Spontaneous fractures of the lesser metatarsals secondary to an amputated hallux and peripheral neuropathy

A general overview of the literature concerning the development of diabetic neuropathic arthropathy is discussed. A case report is presented dealing with spontaneous fractures of the lesser metatarsal in a patient with an amputated hallux and peripheral neuropathy secondary to diabetes mellitus.     

Electrical resistance and macromolecular permeability of brain endothelial monolayer cultures

Electrophysiological measurements were made on endothelial cells initially isolated as individual clones from bovine brain microvessels, and then grown as monolayers on a permeable support of glutaraldehyde-treated collagen gel. When transendothelial cell resistance (R) of the clones was measured, there was a range of values from a low of 157.4 +/- 4.5 omega.cm2 (n = 6) to a high of 783.2 +/- 7.0 omega.cm2 (n = 34). With the high-resistance cells, there was also a small potential difference of -0.46 +/- 0.03 mV luminal-side negative (n = 34). In comparison, endothelial cells from bovine aortas and rat epididymal fat pads cultured on the collagen gels had transendothelial R values of 13.5 +/- 0.2 (n = 62) and 0.45 +/- 0.03 (n = 10) omega.cm2, respectively. Exposure of the high-resistance brain endothelial cell monolayers to a Ca2+-free medium for 10 min decreased the R to 75% of the control values. Addition of Ca2+ back to the medium caused a return of the transendothelial R to control values within 1 h. Endothelial cells were also grown to confluency on microcarrier beads for permeability measurements to Evans blue dye-bovine serum albumin. Microcarriers with no cells (control) and microcarriers with bovine and epididymal endothelial cell monolayers showed no difference in the amount of adsorbed dye. Microcarriers with brain endothelial monolayers excluded up to 80% of the dye. This mammalian brain endothelial culture system will be a useful model for studies of the electrophysiological and permeability properties of the blood-brain barrier.     

Granulocyte antibodies in leukaemic chronic lymphoproliferative disorders

The anti-granulocyte activity of serum from patients with B-cell chronic lymphocytic leukaemia (CLL) and other lymphoproliferative disorders was investigated. Granulocyte-binding IgG was measured in 34 patients with CLL, 13 patients with hairy cell leukaemia, one patient with prolymphocytic leukaemia, two patients with Sézary cell leukaemia, and seven patients with chronic T-cell lymphocytosis who had a predominance of circulating large granular lymphocytes. Anti-granulocyte activity was absent in CLL and its variants, but present in the majority of granulocytopenic patients with chronic T-cell lymphocytosis. In one of these patients, granulocytopenia was associated with complement-activating IgG granulocyte antibody. Thus, antibody-mediated granulocyte injury appears to be an unusual occurrence in chronic lymphocytic leukaemia, but is a frequent complication of chronic T-cell lymphocytosis.     

Circulating immune complex levels in patients with schistosomiasis and complications

Circulating immune complexes (CIC), adult schistosome antibody, and total immunoglobulin concentrations were estimated in sera from 35 chronic Schistosoma mansoni patients with different infection intensities and different pathological complications. High CIC levels were present in about one-third (10/35) of the sera. Most of the patients (9/10) with elevated CIC levels also had hepatomegaly or hepatosplenomegaly. This finding is significant in the pathogenesis of schistosomal liver fibrosis and may also apply to other liver diseases, especially cirrhosis. No correlation was found between infection intensity as judged by stool egg counts and CIC levels. A reverse relationship was observed between the level of anti-adult worm IgG and CIC levels. CIC levels were elevated within 7 and 28 days after treatment in most patients. Hypergammaglobulinaemia was detected in most sera.