Allelic transcripts dosage effect in morphologically normal ovarian cells from heterozygous carriers of a BRCA1/2 French Canadian founder mutation

We hypothesized that the transcriptome of primary cultures of morphologically normal ovarian surface epithelial cells could be altered by the presence of a heterozygous BRCA1 or BRCA2 mutation. We aimed to discover early events associated with ovarian carcinogenesis, which could represent putative targets for preventive strategies of this silent killer tumor. We identified the first molecular signature associated with French Canadian BRCA1 or BRCA2 founder mutations in morphologically normal ovarian epithelial cells. We discovered that wild-type and mutated BRCA2 allelic transcripts were expressed not only in morphologically normal but also in tumor cells from BRCA2-8765delAG carriers. Further analysis of morphologically normal ovarian and tumor cells from BRCA1-4446C>T carriers lead to the same observation. Our data support the idea that one single hit in BRCA1 or BRCA2 is sufficient to alter the transcriptome of phenotypically normal ovarian epithelial cells. The highest level of BRCA2-mutated allele transcript expression was measured in cells originating from the most aggressive ovarian tumor. The penetrance of the mutation and the aggressiveness of the related tumor could depend on a dosage effect of the mutated allele transcript.

A rare case of paraplegia complicating a lumbar epidural infiltration

OBJECTIVE

We report the case of a patient who developed paraplegia following a low lumbar epidural steroid injection. Alternative approaches to (or alternative means of) performing transforaminal injections should be considered, in order to avoid devastating neurological complications.

CASE REPORT

A 54-year-old man (who had undergone surgery 14 years earlier to cure an L5-S1 slipped disc with right S1 radiculopathy) presented with low back pain (which had begun 6 weeks previously) and left S1 radiculopathy. During a second infiltration of prednisolone acetate, the patient reported feeling a heat sensation in his legs and concomitantly developed facial flushing. Immediately after the injection, the patient developed complete, flaccid T7 ASIA A motor and sensory paraplegia. Three days later, T2 magnetic resonance imaging (MRI) of the spine revealed a spontaneous hypersignal in the conus medullaris and from T6 to T9, suggesting medullary ischemia. Recovery has been slow; after 4 months of treatment in a physical and rehabilitation medicine department, urinary and sensory disorders are still present (T7 ASIA D paraplegia). The patient can walk 200 m unaided. Three months later, the MRI data had not changed.

DISCUSSION

This is a rare case report of paraplegia following low lumbar epidural infiltration via an interlaminar route. The mechanism is not clear. Most of authors suggest that the pathophysiological basis of this type of complication is ischemia caused by accidental interruption of the medullary blood supply. Direct damage to a medullary artery, arterial spasm or corticosteroid-induced occlusion due to undetected intra-arterial injection could result in medullary infarction. This serious incident should prompt us to consider how to avoid further problems in the future. It also raises the issue of providing patients with information on the risks inherent in this type of procedure.

CONCLUSION

Despite the rarity of this complication, patients should be made aware of its potential occurrence. In the case reported here, the functional prognosis is uncertain.

Blockage of angiotensin II type I receptor decreases the synthesis of growth factors and induces apoptosis in C6 cultured cells and C6 rat glioma

Angiotensin II (Ang II) is a main effector peptide in the renin–angiotensin system and participates in the regulation of vascular tone. It also has a role in the expression of growth factors that induce neovascularisation which is closely associated to the growth of malignant gliomas. We have shown that the selective blockage of the AT₁ receptor of angiotensin inhibites tumour growth, cell proliferation and angiogenesis of C6 rat glioma. The aim of this study was to study the effects of the blockage of AT₁ receptor on the synthesis of growth factors, and in the genesis of apoptosis in cultured C6 glioma cells and in rats with C6 glioma. Administration of losartan at doses of 40 or 80 mg kg⁻¹ to rats with C6 glioma significantly decreased tumoral volume and production of platelet-derived growth factor, vascular endothelial growth factor and basic fibroblast growth factor. It also induced apoptosis in a dose-dependent manner. Administration of Ang II increased cell proliferation of cultured C6 cells which decreased by the administration of losartan. Our results suggest that the selective blockage of AT₁ diminishes tumoral growth through inhibition of growth factors and promotion of apoptosis.

[Isaac and Jose Horwitz in Chilean psychiatry]

During the XXth century, neuropsychiatrists Isaac and José Horwitz worked in the Asylum, the current Psychiatric Institute Dr José Horwitz. While Isaac dedicated part of his time to teach in Medical and Nursing Schools, his brother José preferred clinical work on mental health. Both chaired consecutively the Service A of the old Hospital and José occupied in his last year the Director's position. After a scholarship in Mental Health in Baltimore, José developed, in conjunction with other outstanding colleagues, the first investigations on psychiatric morbidity in Chile, promoted the use of work therapy for individuals with chronic mental diseases, and helped to improve and plan projects for the prevention and treatment of alcoholism.

Asphalt volcanism and chemosynthetic life in the Campeche Knolls, Gulf of Mexico

In the Campeche Knolls, in the southern Gulf of Mexico, lava-like flows of solidified asphalt cover more than 1 square kilometer of the rim of a dissected salt dome at a depth of 3000 meters below sea level. Chemosynthetic tubeworms and bivalves colonize the sea floor near the asphalt, which chilled and contracted after discharge. The site also includes oil seeps, gas hydrate deposits, locally anoxic sediments, and slabs of authigenic carbonate. Asphalt volcanism creates a habitat for chemosynthetic life that may be widespread at great depth in the Gulf of Mexico.

Video-assisted versus open anterior lumbar spine fusion surgery: a comparison of four techniques and complications in 135 patients

STUDY DESIGN

A retrospective review involved 135 patients undergoing anterior interbody fusion using four different approaches: transperitoneal video-assisted surgery with insufflation, retroperitoneal endoscopic video-assisted surgery, minilaparotomy retroperitoneal surgery, and traditional oblique muscle-splinting retroperitoneal surgery.

OBJECTIVE

To describe and compare the operative procedure and perioperative complications of four different interbody fusion techniques.

SUMMARY OF BACKGROUND DATA

Although anterior lumbar interbody fusion surgery has a long history, several new and innovative approaches have been introduced recently. In contrast to the traditional oblique muscle-splitting retroperitoneal flank incision, the following have been used: a "minilaparotomy" open extraperitoneal approach through a small midline incision, a transperitoneal video-assisted insufflation technique, and a video-assisted gasless retroperitoneal endoscopic technique.

METHODS

A retrospective review was performed using the hospital records, operating room records, and clinic charts of 135 consecutive patients (50 men and 85 women) who underwent surgery between December 1993 and February 1998. Cases were included if either bone grafts alone or cylindrical cages with bone graft inside were used. Cases with anterior instrumentation using plates or rods were excluded. Diagnoses included degenerative disc disease, spondylolisthesis, or pseudarthrosis of a previous lumbosacral fusion. Patients with tumors or infection were excluded. The patients all were adults ranging in age from 17 to 83 years. Among the 135 patients, 12 had undergone previous anterior spine fusion surgery and 64 had undergone prior abdominal surgery.

RESULTS

The onset of new radicular pain or numbness, not experienced by the patient before surgery, occurred in six patients (18%; all with transperitoneal video-assisted surgery using insufflation). Vascular problems occurred in five patients (3.7% overall): two in the transperitoneal video-assisted group (5.9% of the group) and three in the minilaparotomy group (8.7% of the group). Retrograde ejaculation occurred in 4 of the 50 male patients (8% of the group): three in the transperitoneal video-assisted group (25% of the group) and one in the minilaparotomy group (2% of the group). Two patients had ureteral injuries (1.5% overall): one each in the retroperitoneal endoscopic and minilaparotomy groups. Conversion to open procedures was performed in seven patients (11% of the video-assisted procedures). The reasons for conversion included two major vessel lacerations and five peritoneal tears in the retroperitoneal video-assisted group.

CONCLUSIONS

A comparative analysis of four techniques for approaching the lower lumbar spine to perform arthrodesis in 135 patients showed an incidence of complications consistent with the literature for video-assisted techniques, but higher than for open techniques. For these and other reasons, the video-assisted approaches have been abandoned by the surgeons of this report.

[Arturo Vivado Orsini and the renewal of psychiatric treatments]

During the first half of the twentieth century, new psychiatric treatments were discovered, such as malario therapy, insulin therapy, electroshock, penicillin therapy, and the anti-alcoholic aversive therapy. These treatments gave a new hope to mental patients, even in our country. It was precisely while Dr. Arturo Vivado, Full Professor of Psychiatry at the University of Chile, worked and taught, that these treatments were progressively applied in Chile. After an effortful career, Dr. Vivado was appointed Director of the Psychiatric Asylum in Santiago, in 1945. He was a skillful clinician and pragmatic with his psychological belief, equanimus and affectionate with people. His most important contributions to the specialty are described in this review.

Hypertension and coronary heart disease

The association of hypertension and coronary heart disease is a frequent one. There are several pathophysiologic mechanisms which link both diseases. Hypertension induces endothelial dysfunction, exacerbates the atherosclerotic process and it contributes to make the atherosclerotic plaque more unstable. Left ventricular hypertrophy, which is the usual complication of hypertension, promotes a decrease of 'coronary reserve' and increases myocardial oxygen demand, both mechanisms contributing to myocardial ischaemia. From a clinical point of view hypertensive patients should have a complete evaluation of risk factors for atherosclerosis, damage of arterial territories other than the coronary one, and of the extension and severity of coronary artery involvement. It is important to emphasise that complications and mortality of patients suffering a myocardial infarction are greater in hypertensive patients. Treatment should be aimed to achieve optimal values of blood pressure, and all the strategies to treat coronary heart disease should be considered on an individual basis.

Proteolytic processing of the Cyt1Ab1 toxin produced by Bacillus thuringiensis subsp. medellin

Bacillus thuringiensis produces d-endotoxins that require proteolytic processing to become active. The activation of the B. thuringiensis subsp. medellin 28 kDa (Cyt1Ab1) cytolytic toxin by trypsin, chymotrypsin and gut extract from Culex quinquefasciatus larvae was analyzed. The Cyt1Ab1 toxin of B. thuringiensis subsp. medellin was processed by all proteases tested to fragments between 23 and 25 kDa, while processing of the Cyt1Aa1 toxin produce fragments between 22.5 and 24.5 kDa. The Cyt1Ab1 toxin was preferentially processed at the alkaline pH of 12. The in vitro proteolytic processing of the Cyt1Ab1 toxin by C. quinquefasciatus larvae midgut extract showed a 25 kDa fragment; a similar result was observed when the activation was performed in the in vivo experiments. The solubilized Cyt1Ab1 toxin and the protease resistant cores generated by in vitro processing showed hemolytic activity but not mosquitocidal activity. Amino terminal sequence of the C. quinquefasciatus gut extract resistant fragment indicated that the cutting site was located between Lys31 and Asp32, with a sequence DDPNEKNNHNS; while for the trypsin-resistant fragment the cutting site was determined between Leu29 and Arg30, and for the chymotrypsin-resistant fragment between Arg30 and Lys31.

[The Beca's in Chilean psychiatry]

The Chilean psychiatrists, Manuel and Francisco Beca, father and son, who lived at the turn of the XIX century and in the first half of the XX respectively, dedicated their lives to the care of mental patients and to the teaching of psychiatry, contributing in their own way and time to the development of the specialty in Chile. Manuel Beca, a clinician, published the first mental patient statistics and Francisco, an academic, became professor of Psychiatry at the Catholic University. Although they dedicated themselves to different fields in the area of mental health, such as clinical research and teaching, both have outstanding merits to become a part of the historical memory of Chilean psychiatry.

[Prevention of cardiovascular diseases: should the same criteria be applied in Latin America and Europe and North America?]

The prevention of cardiovascular diseases is based on the management of known cardiovascular risk factors by pharmacological means or by modifying lifestyles. A reduction in cholesterol levels is associated with a lower incidence of cardiovascular events and mortality, in both primary or secondary prevention trials. A reduction in blood pressure also leads to a decrease in acute myocardial infarction and the incidence of stroke. Regular exercise is associated with better disease free survival and the effects of smoking cessation are well known. High homocysteine levels are also associated with cardiovascular disease. However, there are no prospective clinical trials showing a beneficial effect of homocysteine reduction on cardiovascular mortality. A change in the type of dietary fat should also be beneficial, but this has not been proven in prospective clinical trials. In Chile, cardiovascular diseases are the leading cause of death among adults and the prevalence of cardiovascular risk factors, including hyperhomocysteinemia is similar to that of European or North American populations. Successful primary and secondary prevention programs to manage these risk factors have been developed in Chile. Therefore, the criteria applied in North America and Europe for the prevention of cardiovascular diseases, should be applied with slight modifications, in Latin American Countries.

Heart rate variability in severe aortic stenosis

BACKGROUND AND AIM OF THE STUDY

Autonomic dysfunction may be a risk factor for the generation of arrhythmias and sudden death in patients with severe aortic stenosis; thus, patients with this condition were studied to assess cardiac autonomic function.

METHODS

Twelve patients (five males, seven females; mean age 63 +/- 13 years) with severe symptomatic aortic stenosis before and after aortic valve replacement, were compared with a control group matched by age and sex. In the study group, mean fractional shortening was 36.5 +/- 5% and maximal aortic gradient 94.7 +/- 12 mmHg, assessed echocardiographically. Autonomic dysfunction was evaluated by following heart rate variability in both time and frequency domains. Spectral analysis was assessed at very low frequency (VLF: 0.017-0.05 Hz), low frequency (LF: 0.05-0.15 Hz) and high frequency (HF: 0.15-0.50 Hz). Heart rate variability was analyzed during three intervals, between 6:00-8:00 am (morning), 14:00-16:00 (afternoon) and 02:00-04:00 (night), and re-evaluated at 8-10 months after aortic valve replacement.

RESULTS

Compared with controls, patients with aortic stenosis presented a significantly lower heart rate variability in the morning and afternoon, analyzed either by time or frequency domain: 50 +/- 22 versus 132 +/- 52 ms (p < 0.05); VLF 5.0 +/- 1.5 versus 7.9 +/- 1.4 ln (ms)2 (p < 0.05); LF 4.9 +/- 1.7 versus 7.5 +/- 1.8 ln (ms)2 (p < 0.05); HF 5.3 +/- 1.4 versus 7.5 +/- 1.8 ln (ms)2 (p < 0.05). Results at night showed a similar tendency, but were not statistically significantly different. At 8-10 months after aortic valve replacement, heart rate variability was increased significantly during the morning, from 50 +/- 22 to 79.5 +/- 22 ms (p < 0.05); VLF from 5.0 +/- 1.5 to 6.7 +/- 0.8 ln (ms)2 (p < 0.05); LF from 4.9 +/- 1.7 to 6.2 +/- 1.3 ln (ms)2 (p < 0.05). HF values tended to increase, though not significantly so. During the remainder of the day there was also a non-statistically significant increment in all values of heart rate variability.

CONCLUSIONS

The study results suggest that patients with severe symptomatic aortic stenosis present with autonomic dysfunction that tends to normalize within the first year of valve replacement.

[The first Chilean journal of psychiatry, neurology and forensic medicine]

This historical review refers to the first Chilean Journal of Psychiatry, Neurology and Forensic Medicine, that was published for the first time in July 1917, and allows to get acquainted of the knowledge level of those times. The publication was in charge of physicians from "Casa de Orates", the Clinic of Nervous and Mental diseases and the Chair of Forensic Medicine. The journal publication was interrupted in 1919. More than half of papers were of psychiatric topics, reviewing a disease or updating treatments. Analysis of psychiatric themes showed a special interest for problems related to hospital management and mental health.

Subcellular distribution of prostaglandin-E2 and prostaglandin-F2 alpha in atrial tissue from patients with mitral valve disease

The distribution of prostaglandin-E2 (PGE2) and prostaglandin-F2 alpha (PGF2 alpha) was studied in subcellular fractions isolated from homogenates of human atrial fresh tissue by differential centrifugation. Right and left atrial samples were excised from the same heart of six patients with mitral valve disease at the time of open heart surgery. The atrial fractions investigated were mitochondrial (8,500 g pellet), microsomal (100,000 g pellet) and cytosol soluble (100,000 g supernatant) fractions. After extraction of prostaglandins from the three atrial fractions and separation of PGE from PGF series by chromatography on silicic acid column, these prostaglandins were measured by radioimmunoassay. The results showed that PGE2 and PGF2 alpha were located mainly in the soluble cytosolic fraction of right and left atrial tissue (p < 0.001). Furthermore, the prostaglandins levels were higher in left than in right atria of these patients (p < 0.001). The relation between prostaglandins heart generation in response to elevated work load of mitral valve disease is discussed.