Cultured human granulosa cells as a model for corpus luteum function: relative roles of gonadotrophin and low density lipoprotein studied under defined culture conditions.

In primates, corpus luteum development involves both gonadotrophin stimulation and exposure to low density lipoprotein (LDL) delivered through vascularization of the granulosa cell-derived layer. These regulatory influences were modelled in vitro using granulosa cells obtained during in-vitro fertilization (IVF) cycles controlled with gonadotrophin releasing hormone (GnRH) analogue, human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (HCG). Granulosa cells were cultured in defined medium on extracellular matrix. Without gonadotrophin or LDL in the medium, progesterone production declined progressively. With LDL alone, there was a short-lived elevation of progesterone output which subsequently declined. Culture with HCG alone resulted in a relatively unchanged rate of steroid production over 5 days despite morphological development. This contrasted with a marked and sustained increase in progesterone output over the same time when granulosa cells were cultured with combined HCG/LDL. Cultures were challenged with combined HCG/LDL on day 5. Where initial incubation included HCG, the challenge resulted in a recovery of progesterone output to values comparable to those of granulosa cells exposed to continuous HCG/LDL. Initial incubation without gonadotrophin led to a reduced response. Results suggest that LDL delivery to granulosa cells of the early corpus luteum causes a short-lived period of progesterone production. Sustained luteinization of granulosa cells and maintenance of gonadotrophin responsiveness requires continued exposure to gonadotrophin in the luteal phase.     

Temporal changes in the mutant frequency and mutation spectra of the 61st codon of the H-ras oncogene following exposure of B6C3F1 mice to N-nitrosodiethylamine (DEN).

Hepatocellular tumors were induced in 15 day old male B6C3F1 mice following a single exposure to N-nitrosodiethylamine (DEN; 5 mg/kg, i.p.). Tumors were collected at 38 and 65 weeks to compare the frequencies and types of mutations in the 61st codon of the H-ras oncogene. The 61st codon was amplified using the polymerase chain reaction (PCR). Allele-specific oligonucleotide (ASO) probes were used to determine the frequency and types of mutations present in these tumors. Forty-nine nodular hepatic lesions were obtained from seven animals at the 38 week timepoint. Five of these samples (10%) had mutations at the 61st codon with one CAA-AAA, one CAA-CGA and three CAA-CTA. Thirty-six nodular hepatic lesions were obtained from six animals at the 65 week timepoint. Ten of these samples (28%) had mutations at the 61st codon with one CAA-AAA, five CAA-CGA and four CAA-CTA. These data indicate that DEN-induced mutations at the 61st codon of the mouse H-ras oncogene (i) are an infrequent event, (ii) have different frequencies at the 38 and 65 week timepoints and (iii) are different from the types of mutations seen in spontaneous lesions.     

Serum IgG and IgM levels in new and regular long-term plasmapheresis donors.

This Australian study monitored the effects of monthly plasmapheresis on donor serum IgG and IgM levels in 127 new and 124 established plasma donors who donated 1014 units over a five-month period. Of the 251 donors, 3% had reduced total serum protein (TSP) levels, 7% had low IgG levels and 12% had low IgM levels prior to donation on at least one occasion over the study period. Statistical analysis showed that the TSP, IgG and IgM levels of new donors who had donated plasma on less than 10 occasions were no more likely to fall below normal than those of old donors. However, new and old donors whose IgG or IgM levels fell below normal at any time during the study had significantly lower levels of the relevant parameter on entry to the study. Followed longitudinally, IgG and IgM levels in old and new donors tended to fall, although levels fluctuated throughout the study. Statistical analysis failed to show any correlation between TSP levels and IgG or IgM levels. These parameters did not correlate significantly with the number of previous plasmaphereses, donor weight, volume collected or history of infection. This study highlighted the need for regular, specific quantitation of IgG and IgM levels as well as TSP in regular plasmapheresis donors. The frequency of testing is yet to be determined, in view of the high materials and labour costs of such a programme.     

The change process in alcoholics: client motivation and denial in the treatment of alcoholism within the context of contemporary nursing

Despite being constantly cited as a critical intervening variable in the recovery from alcohol problems, there is a paucity of literature on client motivation. This paper reviews the current literature which impacts on motivation and its importance in treatment and develops in a stepwise manner the revised expectancy/motivation hypothesis, tentatively explaining both motivation and denial as a natural process in behavioural change. Because of the revised expectancy/motivation hypothesis' distinctly defined stages which closely relate to the process of nursing and the qualitative and quantitative measurement it entails which the nursing process demands, it offers a particularly appropriate model for treatment within nurse practice.     

Tubulin and microtubules in cochlear hair cells: comparative immunocytochemistry and ultrastructure

The distribution of tubulin has been investigated in surface preparations of the guinea pig organ of Corti using indirect immunofluorescence microscopy. Two different monoclonal antibodies to tubulin produce similar distinct patterns of labelling in hair cells. Labelling is greater in inner hair cells than outer hair cells. It occurs in rings around the cell apex, and in a meshwork below and channels through, the cuticular plate. In outer hair cells from the apical region of the cochlea, labelling occurs around the location of a basalward protrusion of the cuticular plate. These patterns correlate with the location of microtubules observed using transmission electron microscopy. A large patch of labelling occurs on the strial side of the cell corresponding to the largest channel through the cuticular plate and the kinociliary basal body. Strands of labelling are seen running parallel to the long axis of the cell between the subcuticular and synaptic region. Many more of these strands are seen in the inner hair cell than the outer hair cell and may correspond to tracks of microtubules transporting neurotransmitter vesicles or other organelles. In outer hair cells, intense labelling and many microtubules are seen in the subnuclear region. The possible roles of the different microtubule arrangements are discussed.     

In situ saphenous vein bypass grafts: angiographic evaluation and interventional repair of complications

In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.     

Current Controversies in Pregnancy and Epilepsy: A Unique Challenge to Nursing

Approximately 11,550 women with epilepsy give birth annually, yet maternity nurses receive little information on how to care for these patients. Children of epileptic mothers are born with an increased incidence of birth defects, and have a higher perinatal mortality rate. Complications such as bleeding during pregnancy, and interventions such as cesarean births and labor inductions are more common among epileptic women, and seizures tend to increase during pregnancy in more than one-third of epileptic women. Informed nursing care is essential to ensure the best possible outcome of these pregnancies.     

A Predictive Index for Postoperative Deep Vein Thrombosis in Thoracic Surgery Patients

In a single-centre prospective trial 200 consecutive patients undergoing thoracic surgery were randomised to receive one of two prophylactic regimes against deep vein thrombosis (DVT). These were 5000 units of subcutaneous heparin twice a day, alone or combined with the wearing of graded compression stockings. The diagnosis of DVT was made clinically and with ¹³¹I labelled fibrinogen. Six DVTs developed in the stocking group and 11 in the non-stocking group. The results suggest that the use of stockings reduces the incidence of DVT when added to herparin but the difference is not statistically significant. To obtain a predictive index for the development of DVT, discriminant analysis was applied to the control and stocking groups separately and combined. Five simple clinical variables gave a true positive prediction rate, for the combined group, of 94% and a false positive prediction rate of 26%.