Techniques for the rapid preparation of permanent slides of microscopic algae

Because most techniques for the preparation of permanent mounts of algae have hitherto involved long alcoholic dehydration series, which frequently result in cell collapse if cut short, a method has been developed which is anhydrous from the start and avoids these series. It can be used to produce rapidly, permanent, generally-stained mounts of most microscopic algae in which the degree of shrinkage of the cell or its contents is reduced to a minimum.

A method for the cleaning and mounting of diatoms is also given.     

Streptokinase in central retinal vein occlusion: a controlled clinical trial.

Forty patients with central retinal vein occlusion were allocated at random either to a treatment group given streptokinase followed by anticoagulatns or to a control group given no specific treatment. The two groups, which were each of 20 patients, were broadly similar in respect of clinical and laboratory values and similar in their initial visual acuity. At follow-up ("final" vision) the visual acuity in the treated group was significantly better than in the untreated group. Only one treated patient developed thrombotic glaucoma compared with four controls. Streptokinase may, however, have been responsible for vitreous haemorrhage (and permanent loss of vision) in three patients and hence probably has only a limited role in the treatment of central retinal vein occlusion.     

Cardiovascular collapse in laparoscopy

This report describes two cases of severe cardiovascular collapse occurring during laparoscopy using carbon dioxide insufflation under general anesthesia. Both patients made eventual complete recovery. The possible causes, gas embolism being the most likely, are discussed. A list of precautions for the safe conduct of laparoscopy is presented. Since these precautions have been followed there has been no recurrence of cardiovascular collapse in over 300 subsequent cases.     

Intensive treatment of respiratory failure--personal experiences

Controlled oxygen-therapy was used in 30 out of 49 patients (61%) with the acute respiratory failure or exacerbations of the chronic respiratory failure treated at ICU (Group Y), while artificial ventilation in the remaining 19 patients (39%; Group B). An improvement was achieved in 70% of patients of Group A and 42% in Group B. Overall improvement was achieved in 59% of the treated patients. There were 69% of treated patients with infections. Totally 41% of the treated patients died (30% of Group A and 58% of Group B). An analysis of the results has been carried out in various subgroups of the treated patients, i.e. the acute and exacerbated respiratory failure as well as partial and complete respiratory insufficiency. The result of high risk patients have also been analysed. This subgroup included sudden cardiac arrest, shock and non-compensated acidosis. Favourable effects of the intensive care of patients with infections have been discussed with particular reference to the life hazard in case of septic complications. Emphasis is on the unfavorable effects of therapy in patients with respiratory failure complicated with pulmonary embolism. Indications to the use of respirator and complications of the artificial ventilation have been discussed.     

Retinal axon growth cone responses to different environmental cues are mediated by different second-messenger systems

Numerous studies have shown that the developing tip of a neurite, the growth cone, can respond to environmental cues with behaviors such as guidance or collapse. To assess whether a given cell type can use more than one second-messenger pathway for a single behavior, we compared the influence of two well-characterized guidance cues on growth cones of chick temporal retinal ganglion cells. The first cue was the repulsive activity derived from the posterior optic tectum (p-membranes), and the second was the collapse-inducing activity derived from oligodendrocytes known as NI35/NI250. p-Membranes caused permanent growth cone collapse with no recovery after several hours, while NI35 caused transient collapse followed by recovery after about 10 min. The p-membrane-induced collapse was found to be Ca²⁺ independent, as shown using the Ca²⁺-sensitive dye Fura-2 and by the persistence of collapse in Ca²⁺-free medium. Dantrolene, a blocker of the ryanodine receptor, had only a minor effect on the collapse frequency caused by p-membranes. In contrast, the NI35-induced collapse was clearly Ca²⁺ dependent. [Ca²⁺] increased sevenfold preceding collapse, and both dantrolene and antibodies against NI35 significantly reduced both the Ca²⁺ increase and the collapse frequency. Thus, even in a single cell type, growth cone collapse induced by two different signals can be mediated by two different second-messenger systems. © 1997 John Wiley & Sons, Inc. J Neurobiol 33: 825–834, 1997     

The use of resorbable spacers for nasal spreader grafts

The concept and technique of the use of resorbable synthetic material for nasal spreader grafts are presented. The material is felt to be particularly useful in revision rhinoplasty, in which the likelihood of internal valve collapse is high and the septum (the most common source of material for spreader grafts) often has already been harvested. The material used is a commercially available polymer of polylactic and polyglycolic acid, Lactosorb. It is supplied as a mesh sheet that can be cut to an appropriate size for spreader grafts. Although the material absorbs after approximately 12 months, it is believed that this is sufficient time for the upper lateral cartilages to be stabilized by fibrosis in their new position and to maintain the appropriate internal valve angle. This material was used on 10 patients with valvular collapse undergoing secondary rhinoplasty. In follow-up observations ranging from 12 to 18 months, there has been no recurrence of airway obstruction.     

COBALT-60 TELETHERAPY OF INTRA-ORAL CANCER

Forty patients with intra-oral cancer were given cobalt-60 teletherapy upon the primary lesion.Among the physical advantages of this method are the more precise direction of the beam, reduced scatter and lessened skin and bone effects. The period of observation of patients treated has not been long enough to warrant discussion of cure or permanent arrest, but the consistency and regularity of disappearance of the primary lesion was significant. The authors believe that for intra-oral cancer, cobalt-60 teletherapy should be used before radical surgical procedures are proposed.     

Successful treatment of 19 consecutive groin lymphoceles with the assistance of intraoperative lymphatic mapping

Postoperative groin lymphoceles that fail to resolve spontaneously or with interventional therapy present a formidable problem that is associated with a high degree of morbidity. Numerous interventional methods and operative techniques have been described to treat these fluid collections, yet recurrence rates remain high. The use of lymphatic mapping has gained widespread use in the treatment of cutaneous malignancies and breast cancer and has been proven effective in delineating the course of lymphatic channels. We present here a series of 17 consecutive patients with 19 problematic groin lymphoceles who were treated with the assistance of intraoperative lymphatic mapping using isosulfan blue dye. To date there have been no recurrences and minimal morbidity associated with the technique and prescribed postoperative treatment regimen.     

Notes on Technic

This report details a whole mount technique which allows rapid assessment of meiotic stages in large numbers of mammalian oocytes using an aceto-orcein stain.

Previous studies of mammalian oocyte meiosis have been hampered by the use of time-consuming staining techniques. Temporary preparations have been produced using squashes of oocytes with fixative and stain drawn under the coverslip by diffusion (Austin 1961). An air-drying technique requires less attention by the technician and allows permanent preparations to be made (Tarkowski 1966). However, these methods require that each slide be treated individually. The improvements outlined below permit many slides to be processed together, allowing surveys of larger numbers of oocytes than before.     

Role of stress fibers in the association of intermediate filaments with microtubules in fibroblast cells.

The association between intermediate filaments (IF) and microtubules (MT) has been demonstrated by several experiments using MT inhibitors and by microinjecting specific antibodies. The actin cytoskeleton has recently been assigned a role in this process of drug induced IF collapse. However, this was not found to be true in large cells with irregular morphology. For instance, in early passage diploid fibroblasts of human origin and in armadillo cell lines, where the cells are large, irregular in shape and exhibit prominent stress fibers ( SF ), depolymerization of MT with nocodazole did not lead to collapse of IF . Instead, the IF formed bundles of coils that seemed to associate with the SF . Disintegration of the SF with cytochalasin B led to the collapse of the IF . It appears that the actin organization in such large cells with extensive SF , is not as contractile as in typical spindle shaped fibroblasts which have relatively less stable actin organization. The stable SF may actually prevent IF collapse.     

Tracheostomy Tube Failure in Obstructive Sleep Apnea

In our institutions we routinely do posttracheostomy sleep studies on patients being treated for obstructive sleep apnea. We have identified several patients who failed to show objective evidence of improvement after tracheostomy. From our studies we have found that both mechanical obstruction and concomitant respiratory control dysfunction caused this failure. A unique tracheostomy tube was constructed to treat the subset of patients with internal collapse of the tracheostomy tube.     

REFRACTORY HYPOTENSION—Diagnosis and Management in Surgical Patients

Refractory hypotension is circulatory collapse of obscure cause which occurs in surgical patients who are thought to have a normal blood volume but in whom adequate circulation cannot be maintained. Such patients are usually treated empirically by the administration of intravenous vasopressor agents, and the mortality rate is relatively high.A specific diagnosis of the underlying cause for the refractory hypotension can be made by thorough clinical evaluation. Specific treatment aimed at correcting the underlying cause of the vascular collapse will lower the mortality rate in this serious type of circulatory failure.     

Pathogenesis of obstructive sleep apnea.

The pathogenesis of obstructive sleep apnea (OSA) has been under investigation for over 25 years, during which a number of factors that contribute to upper airway (UA) collapse during sleep have been identified. Structural/anatomic factors that constrict space for the soft tissues surrounding the pharynx and its lumen are crucial to the development of OSA in many patients. Enlargement of soft tissues enveloping the pharynx, including hypertrophied tonsils, adenoids, and tongue, is also an important factor predisposing to UA collapse, inasmuch as this can impinge on the pharyngeal lumen and narrow it during sleep. Other factors, including impairment of UA mechanoreceptor sensitivity and reflexes that maintain pharyngeal patency and respiratory control system instability, have also been identified as possible mechanisms facilitating UA instability. This suggests that OSA may be a heterogeneous disorder, rather than a single disease entity. Therefore, the extent to which various pathogenic factors contribute to the phenomenon of repetitive collapse of the UA during sleep probably varies from patient to patient. Further elucidation of specific pathogenic mechanisms in individuals with OSA may facilitate the development of new therapies that can be tailored to individual patient needs according to the underlying mechanism(s) of their disease.     

OBITUARIES

Thirty-three patients with heart block were treated by implantation of a permanent transvenous pacemaker. There were no deaths and few complications even though 25 of these patients were over 70 years of age. Follow-up examinations, including electrocardiograms, were done in all patients.The technique of the operation is discussed and the importance of performing it under fluoroscopic guidance in a proper surgical operating suite is emphasized. This arrangement may require the use of a portable image intensifier.This simple, effective procedure can be performed under local anesthesia and with safety, even in the elderly, frail or debilitated patient. Currently it is the authors'' method of choice in the treatment of heart block; thoracotomy is now obsolete unless a synchronous pacemaker is needed or a permanent transvenous pacer cannot be inserted.     

Staged use of soft-tissue expansion and lower thoracic advancement flap in breast reconstruction

A single patient is presented in whom breast reconstruction after mastectomy for breast cancer has been achieved by sequential use of soft-tissue expansion followed by permanent silicone implant placement and thoracic flap advancement to define the inframammary fold. This procedure may play a useful role in patients in whom other, more complex methods of breast reconstruction are not selected or indicated and in particular in patients in whom bilateral silicone implants are utilized.     

Studies on the relationship of a collapsed chromosomal morphology to the production of Q- and G-bands.

A study has been made of the relationship of the collapsed chromosomal morphology to the production of Q- and G-bands. Our previous observations on the ASG and BSG banding techniques have been extended to include the trypsin, quinacrine dihydrochloride and quinacrine mustard techniques. In all but the quinacrine dihydrochloride technique, a collapse occurred prior to staining and in the exception a collapse occurred on washing after staining. Further studies, using a series of buffers of constant ionic strength, have shown that the collapse was pH dependent and the efficiency with which a collapse occurred increased with increasing pH. On returning such collapsed chromosomes to a pH of below 2.6 they reattained a normal morphology. The present results suggest that although the induction of a collapsed state does not lead to banding, the absence of a collapsed state may prevent the production of bands.     

Familial juvenile hyperuricaemic nephropathy is not such a rare genetic metabolic purine disease in Britain

Renal disease is rare today in classic adult gout, and gout is rare in renal disease--especially in the young. Here we summarise studies in 158 patients from 31 kindreds diagnosed with familial juvenile hyperuricaemic nephropathy FJHN from a total of 230 kindred members studied in Great Britain. Some patients have been followed for up to 30 years, and allopurinol has ameliorated the progression of the renal disease in all 113 surviving members provided: They have been diagnosed and treated sufficiently early. Compliance with allopurinol treatment and diet has been as important as early recognition. Hypertension has been rigorously controlled. The use of oral contraceptives has been avoided, as has pregnancy in any female with a Glomelar Filtration Rate GFR <70 ml/min. The question arising is: Why is FJHN the most prevalent genetic purine disorder diagnosed in Britain? Is it a lack of awareness which needs to be improved Europe-wide?     

70 years of permanent plot research in The Netherlands

Abstract. Within the framework of the Dutch ‘Network Ecological Monitoring’, a large set of new permanent plots has been established to monitor selected plant communities throughout The Netherlands for studying the effects of environmental changes on species composition of semi‐natural communities. This national programme will also make use of pre‐existing permanent plots. These plots reflect the long and comprehensive history of research using permanent plots in The Netherlands, where the first permanent plots were established in the early 1930s. To enhance the usefulness of preexisting permanent plots, a comprehensive permanent plot database was compiled. This database was derived from the Dutch National Vegetation Database, that was established for the recent vegetation classification of The Netherlands. This was supplemented with information from various organizations and a number of individual researchers. Currently, the permanent plot database contains ca. 6000 permanent plots. More than 2500 of these plots have been sampled at least 5, and ca. 1500 plots at least 10. Most of the plots are from grasslands, followed by forests and dune systems. This database not only provides insight into vegetation succession, fluctuations within plant communities over time, and the effects of changes of the environment on the vegetation but, indirectly, italso offers the possibility of studying the long‐term behaviour of individual plant species (e.g. establishment, competition, longevity). For the Network Ecological Monitoring a selection of these (historical) plots will be added to the new network of permanent plots in The Netherlands, thus supplying information of past vegetation conditions.     

Prévention des risques d’infertilité liés aux traitements antitumoraux dans le cancer du testicule

In recent years, chemo- and radiotherapy for cancer patients have become increasingly successful, and sustained remissions have been achieved. However in young men, most of the current therapies still presently induce temporary or permanent infertility without any means of prediction. This is also true in the case of testicular cancer which is now the most frequent cancer in young adults males. Moreover, this problem is particularly crucial in patients with a testicular cancer since they have a poor semen quality before any antitumoural therapy. The present paper largely based on data accumulated over 25 years at CECOS Paris Cochin reviews the modalities and clinical usefulness of semen cryopreservation in young men with testicular cancer. Recent use of cryopreserved semen samples through ART has provided a growing number of pregnancies. These new data strongly demonstrate that semen cryopreservation should be offered to all men diagnosed with a testicular cancer since it provides the only reasonable chance of establishing a pregnancy after therapy.     

Monoclonal antibody therapy of chronic lymphocytic leukemia

Cure of patients with chronic lymphocytic leukemia (CLL) has been an elusive goal. The recent availability of active monoclonal antibodies has rekindled enthusiasm for new and innovative therapeutic approaches. Alemtuzumab, induces responses in about a third of patients with relapsed or refractory CLL following therapy with fludarabine and an alkylating agent. Whereas, rituximab has limited activity in previously treated patients, response rates of 50-70% have been reported in those without prior therapy. Recent data on combinations with rituximab and chemotherapy have shown promise for improving patient outcome. Newer antibodies in development include the primatized monoclonal antibody lumiliximab (IDEC-152), directed against CD23. Other biological approaches include the use of antisense oligonucleotides, proapoptic small molecules, and vaccines directed against the malignant B cells. The rational development of combinations of these promising approaches may eliminate the need for chemotherapy, leading to safer and more effective approaches for patients with CLL.