Examining the dynamics of spouse abuse: an alternative view

Spouse abuse continues to be a great problem in our society. Much of the literature about the problem, however, assumes that the roles of perpetrator and victim are always fixed, with the man as perpetrator and the woman as victim. This perception is understandable if the injuries received are the focus of attention, and the sole informant about the violence is the person who has most often been the recipient of injuries. On occasions when both partners are interviewed, a different perception of violent relationships is likely to emerge. Violence can be viewed as occurring along a continuum. One extreme is represented as mutual combat, in which both partners play a role in the escalation of conflict. The other extreme follows the traditional concept of battering where the woman is victimized by the man. Primary care practitioners are in a position to assist clients who are in violent relationships and to help them learn more functional problem-solving skills. This article focuses on methods of identifying violent couples and teaching them how to interrupt the cycle of violence.     

Quantitative effects of cerebral infarction on spatial learning in rats.

Outcome following stroke is difficult to measure because the behavioral response to infarction is variable. We hypothesized that cognitive function, such as spatial learning, may be a reproducible and sensitive outcome variable. We developed an animal model of multifocal cerebral ischemia in order to study the effects of infarction on learning. To cause ischemia, several hundred microspheres were injected into the internal carotid arteries of rats. After ischemia, behavior was measured using a global rating and a Morris water maze. Postmortem serial brain sections were stained and the size of the infarctions was measured. We found that intracerebral microspheres caused cortical infarction and an impairment of spatial learning. This impairment was not due to occlusion of the internal carotid artery and was not found in animals who received a sham injection of saline. The degree of learning impairment was not correlated with the volume density of the infarctions or with the volume density of the remaining cerebral hemisphere. The learning impairment clearly differentiated normal from lesioned animals, and the impairment was probably due to a delay in acquisition of spatial information rather than a defect in retention or retrieval. Measurement of learning deficit after cerebral ischemia is an efficient and sensitive method for evaluating new stroke treatments and possibly for exploring structure function relationships.     

Imaging of thoracic aortic dissection

Acute thoracic aortic dissection has a high mortality if untreated, so the diagnosis must be rapidly made if mortality is to be lowered significantly. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause for death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 of 12 patients studied and correctly classified the type in only five. Aortography was performed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were performed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention.     

Postoperative radiotherapy for locally advanced colon cancer

Background: The role of adjuvant postoperative radiotherapy for locally advanced colon cancer is not well documented. Methods: Seventy-eight patients who underwent a complete resection of B2-C colon cancer received postoperative radiotherapy. Twenty-eight patients received ⩽45 Gy; 50 patients received 50–55 Gy. Twenty-seven patients received adjuvant fluorouracil-based chemotherapy. All patients were followed for a minimum of 3 years; no patients were lost to follow-up. Results: The overall local control rate was 88%. The 5-year actuarial rate of local control was 96% after 50–55 Gy postoperative radiotherapy compared with 76% after <50 Gy (p=0.0095). Multivariate analysis of local control showed that only radiotherapy dose significantly influenced this end point. Cause-specific survival rates at 5 years were B2, 67%; B3, 90%; C1, 100%; C2, 61%; C3, 36%; and overall, 63%. Multivariate analysis of cause-specific survival showed that only stage significantly influenced this end point. Bowel obstruction caused by adhesions developed in three patients and required a laparotomy; radiation-induced sarcoma developed in one additional patient. Conclusions: Postoperative radiotherapy appears to reduce the risk of local recurrence in patients with locally advanced colon cancer. The optimal dose is probably 50–55 Gy at 1.8 Gy per fraction. Postoperative radiotherapy may improve cause-specific survival for patients with stages B3 and C2 cancers.     

Production of genetically modified cells expressing specific transgenes by retroviral vectors for gene therapy

Summary Techniques and protocols are described for the generation of genetically modified cells that can be used for gene therapy. Primary fibroblast cultures are established from skin biopsies, maintained in culture, frozen for long-term storage, and retrieved when necessary. Retroviral packaging cell lines are generated by transfection of DNA into retroviral packaging cells by calcium-phosphate precipitation method or by lipofection method. To generate cell lines expressing high titer virus, individual colonies of cells are cloned and the virus titer is determined. Virus collected from packaging cells expressing high titer virus is then used to infect primary fibroblasts. To obtain fibroblast cell lines expressing high amounts of transgenes, individual cells can be cloned to generate clonal cell lines. Although the methods described here are for fibroblasts, the same methods or modification of the methods can be used for other cell types.     

An investigation of the post-tetanic potentiation of end-plate potentials at a mammalian neuromuscular junction

1. End-plate potentials (e.p.p.s) were recorded intracellularly from neuromuscular junctions in curarized or Mg-paralysed rat diaphragm-phrenic nerve preparations in vitro. In Mg-paralysed preparations after 1000 impulses at 100/sec the amplitude of e.p.p.s elicited at 1/sec before and after the tetanus was on average greater than the control amplitude for 120 +/- 30 sec.2. The post-tetanic potentiation (P.T.P.) of e.p.p. amplitudes was not thought to be dependent upon post-tetanic hyperpolarization (P.T.H.) of nerve terminals as it lasted longer than the hyperpolarization generated by an identical tetanus; was unaffected by hyperpolarizing currents which reduced P.T.H. or depolarizing currents which prolonged P.T.H.; and was diminished in solutions containing 30% of the normal NaCl concentration or 1% ethyl alcohol, both of which procedures prolong P.T.H. The magnitude and duration of P.T.P. were influenced by the pH of the bathing solution in the range 7-7.5 although there was no change in P.T.H. under these conditions. The inability of polarizing currents to influence P.T.P. was also thought inconsistent with the hypothesis that P.T.P. is due to an increase in available transmitter.3. P.T.P. was not thought to be due to sodium accumulation in nerve terminals, for P.T.P. was reduced or abolished by procedures which would be expected to increase the intraterminal sodium ion concentration. These procedures were: exhibition of metabolic inhibitors (1.8 x 10(-6)M antimycin A, 3-5 mM sodium azide or 1 mM sodium iodoacetate), exhibition of cardiac glycosides (7.7 x 10(-6)M digoxin or 0.42 mM ouabain), and omission of glucose or potassium ions from the bathing solution. Abolition of P.T.P. by potassium-free solutions was also thought to be inconsistent with the hypothesis that P.T.P. is due to a reduction in the potassium concentration in nerve terminals.4. P.T.P. was not thought to be due to terminal volume changes, for no consistent effect upon the quantal content of e.p.p.s could be detected in hypo- or hyperosmotic solutions.5. It was concluded that the only hypothesis for P.T.P. not excluded by our experiments was that P.T.P. is due to some change in ionized calcium at a membrane site important in transmitter release.     

Neural stem cells from adult hippocampus develop essential properties of functional CNS neurons

Neural stem cells are present both in the developing nervous system and in the adult nervous system of all mammals, including humans. Little is known, however, about the extent to which stem cells in adults can give rise to new neurons. We used immunocytochemistry, electron microscopy, fluorescence microscopy (FM imaging) and electrophysiology to demonstrate that progeny of adult rat neural stem cells, when co-cultured with primary neurons and astrocytes from neonatal hippocampus, develop into electrically active neurons and integrate into neuronal networks with functional synaptic transmission. We also found that functional neurogenesis from adult stem cells is possible in co-culture with astrocytes from neonatal and adult hippocampus. These studies show that neural stem cells derived from adult tissues, like those derived from embryonic tissues, retain the potential to differentiate into functional neurons with essential properties of mature CNS neurons.     

Electric activity in the neocortex of freely moving young and aged rats

Electroencephalographic activity of the neocortex was evaluated in young (5-7 months) and aged (26-28 months) rats. All animals in the aged group showed behavioral impairment in a spatial task (water maze). A neocortical electroencephalogram was derived simultaneously from 16 different neocortical locations and was subjected to spectral analysis. The frequency of occurrence and duration of high-voltage spindles was determined in two sessions, each involving a total of 30 min alert immobility. Changes in spectral characteristics and high-voltage spindles in response to scopolamine administration were also evaluated. The power of high-frequency activity (8-20 Hz) was significantly reduced in the aged subjects. This was greatest in the temporo-occipital regions, while no significant changes were seen in the mediofrontal region. Scopolamine resulted in a large power increase in all frequency bands, but the increase in the higher-frequency range (8-20 Hz) was significantly less in the aged group. The incidence of high-voltage spindles was 6 times higher and their total duration was 9 times longer in aged rats, with virtually no overlap with the young group. In young rats, scopolamine increased the incidence and total duration of high-voltage spindles, while it decreased both parameters in the aged subjects. Cholinergic neurons in the nucleus basalis appeared shrunken in the aged animals. These findings demonstrate that reliable electroencephalographic changes are present in the neocortex of the aged rat, and that some of the physiological alterations may be due to the pathological changes in the cholinergic nucleus basalis.     

Managing the cancer risk in chronic ulcerative colitis. A decision-analytic approach

Chronic ulcerative colitis is associated with a high risk of colon cancer. The most appropriate management--prophylactic proctocolectomy or medical surveillance--is, at present, unclear. Recent reports suggest that the presence of colonic dysplasia or "precancer" on endoscopic biopsy may be a reliable predictor of concurrent or future colon cancer. To assess the value of colonic dysplasia in managing colitis patients, I applied decision analytic techniques to currently available data regarding the sensitivity and specificity of colonic dysplasia in colitis patients. Such analysis shows that management based on biopsy for colonic dysplasia, rather than prophylactic proctocolectomy for all colitis patients, will maximize 5-year survival. Sensitivity analysis suggests that management is primarily determined by the sensitivity of biopsy-diagnosed dysplasia--elective prophylactic surgery would be preferred only when sensitivity of dysplasia on biopsy is less than or equal to 0.70 at 20 years, or less than or equal to 0.85 at 30 years of colitis, and changing surgical mortality and survival benefit from early diagnosis within a range established by previous studies affects management decisions only when sensitivity of dysplasia is at the lower end of its reported range.