Darkfield Light Microscopes

What are the Uses of Dark Field Light Microscopes?

darkfieldlightmicroscopes — Fri, 03 Aug 2007 04:34:13 +0000

Darkfield illumination is comparable to viewing star or clusters of stars on a dark night. They seem so near in spite of their great distance from the Earth. Sounds appealing? Well, this is due to a dark background in contrast to the sparkling light of the stars. But this magnificent view can only be seen during night time and with the use of a telescope. Scientists or some science majors on the other hand use darkfield light microscopes; similarly they can give the same magnificent view; only that it can be seen anytime with proper equipment and lighting effects. (more…)

Vital Information about Unicellular Organisms and Application of Dark Field Light Microscopy

darkfieldlightmicroscopes — Fri, 03 Aug 2007 04:33:37 +0000

There are many unicellular organisms abounding our planet and their behaviors and reactions are very interesting to study and observe. It should be noted that certain organisms yield benefits but some can be harmful and fatal. It is in this light that many scientists nowadays are continuously studying and observing unicellular or multi-cellular organisms. Dark field light microscopy is important for studying unicellular microorganisms. There are many techniques that can be used and all depends on the unicellular organisms to be observed. Among the many unicellular organisms are: (more…)

How Important Is Live Blood Analysis and Dark Field Light Microscopy?

darkfieldlightmicroscopes — Fri, 03 Aug 2007 04:32:53 +0000

Dark field light microscopy is a very important tool used in live blood analysis. While the whole concept is rather new, the idea is fast becoming popular today. In fact a handful of experts are already performing it. Understand what live blood analysis is and how it works through the article below. (more…)

Cells Tissue Formation Observation and Dark Field Microscopy

darkfieldlightmicroscopes — Fri, 03 Aug 2007 04:32:10 +0000

The principles of dark field microscopy is mostly used in observing cells and tissues. And the key to all of it is to understand what dark field microscopy’s role is in this endeavor and how it had made all the researches possible.

When comparing dark field optics with phase contrast optics, dark field optics are priced a little bit cheaper. But then again, some superior dark field microscopes are capable of producing images of better quality than some of the low quality phase contrast microscopes available in the market today. Dark field microscopes basically produce an image of the specimen against a dark background. This is what makes it different from standard microscopes and the bright field microscopes, which both produce an image of the specimen on a plain white background. (more…)

How Does Brightfield/Darkfield Light Microscopy Works?

darkfieldlightmicroscopes — Fri, 03 Aug 2007 04:31:11 +0000

The principles behind brightfield/darkfield light microscopy are relatively complex. In essence, they are the concepts that allows the users to have a better view of the specimens that they are observing. (more…)

Diaphragmatic Hernias

darkfieldlightmicroscopes — Tue, 31 Jul 2007 08:17:41 +0000

With the advent of clinical radiology and microscopes such as darkfield light microscopes, it became evident that a di¬aphragmatic hernia was a relatively common abnormality and not always accompanied by symptoms. Three types of esophageal hiatal hernia were identified: (1) the sliding hernia, type I, char¬acterized by an upward dislocation of the cardia in the posterior mediastinum; (2) the rolling or paraesophageal her¬nia, type II, characterized by an upward dislocation of the gastric fundus alongside a normally positioned cardia and (3) the combined sliding-rolling or mixed hernia, type III, charac¬terized by an upward dislocation of both the cardia and the gastric fundus. The end stage of type I and type II hernias occurs when the whole stomach migrates up into the chest by ro¬tating 180 degree around its longitudinal axis, with the cardia and pylorus as fixed points. In this situation the abnormality is usually referred to as an intrathoracic stomach. (more…)

Cervical and Upper Thoracic Esophageal Cancer

darkfieldlightmicroscopes — Tue, 31 Jul 2007 08:15:13 +0000

When considering resection, tumors of the esophagus (best diagnosed using specialized medical microscopes or even darkfield light microscopes) are best divided into those above and those below the carina. Czerny reported the first successful resection of a carcinoma of the cervical esoph¬agus in 1877. It was hoped that the prognosis for patients with this disease might be better than for those with carcinoma of the thoracic esophagus, but this has not proved to be the case. Early experience with resection of the cervical esophagus resulted in a high mortal¬ity rate, and reconstruction by neck flaps often required multiple operations. Because of these complexities and the generally dis¬appointing results, radiotherapy frequently was elected. Immediate mortality decreased, but control of the tumor was not satisfactory even with early diagnosis using darkfield light microscopes. (more…)

Caustic Injury

darkfieldlightmicroscopes — Tue, 31 Jul 2007 08:11:09 +0000

Accidental caustic lesions occur mainly in children, and in general, rather small quantities of caustics are taken. In adults or teenagers, the swallowing of caustic liquids is usually deliberate, during suicide attempts, and greater quantities are swallowed. Alkalies are more frequently swallowed accidentally than acids, because strong acids cause an immediate burning pain in the mouth. (more…)

Tumors of the Thoracic Esophagus and Cardia

darkfieldlightmicroscopes — Tue, 31 Jul 2007 08:08:23 +0000

Tumors, usually diagnosed using microscopes such as darkfield light microscopes, which arise below the carina, the preference of these authors is either an en bloc resection for cure or a transhiatal removal for palliation. A curative procedure is performed according to the principles of an en bloc resection in continuity with the regional lymph nodes. It is attempted in a patient whose pre¬-resection physical condition and tumor characteristics, as examined under darkfield light microscopes, have the potential for long-term survival. The en bloc resection is done through three incisions in the following order: (1) right posterolateral thoracotomy, en bloc dissection of the distal esophagus, mobilization of the esophagus above the aortic arch, closure of the thoracotomy repositioning of the patient in the recumbent position; (2) upper midline abdominal incision, en bloc dissection of the stomach associated lymph nodes; and (3) left neck incision and proximal division of the esophagus. The specimen is removed transhiatally and the stomach is divided at the angulus, preserving the antrum. Gastrointestinal continuity is re-established with a left colon in¬terposition. During the thoracic and abdominal dissection, intraoperative staging is done. If during the course of the operation an incurable situation is identified, the en bloc resection is abandoned and a palliative resection is performed in a manner similar to that described for tumors of the middle and upper thoracic esopha¬gus. The hospital mortality for patients undergoing a curative en bloc resection is similar to those undergoing a palliative transhiatal resection. If preoperative staging has shown that the patient is a candidate for palliative resection, a transhiatal esophagectomy is performed. A standard left thoracotomy with in¬trathoracic anastomosis for lower lesions or an Ivor Lewis com¬bined approach for higher lesions is not advocated because of (1) the proven need to resect long lengths of the esophagus to erad¬icate submucosal spread, (2) the higher morbidity associated with a thoracic anastomotic leak, and (3) the high incidence of esophagitis secondary to reflux following an intrathoracic anastomosis. (more…)

Extent of Resection to Cure Disease Confined to the Mucosa

darkfieldlightmicroscopes — Tue, 31 Jul 2007 08:06:25 +0000

The development of surveillance programs for the detection of early squamous cell carcinoma in endemic areas using darkfield light microscopes or any other medical microscopes and for early adenocarcinoma in patients with Barren’s esophagus has given rise to controversy over how to manage tumors (diagnosed using a microscope such as a darkfield light microscope) confined to the mucosa. Some authors have endoscopically resected squamous carcinomas after using endoscopic ultrasound to determine that the depth of the tumor was limited to the mucosa. Surprisingly, large areas of squamous mucosa can be resected without perforation or bleeding, leaving the smooth surface of the muscularis mucosae intact. Re-epithelialization of the large artificially induced ulcer is usu¬ally complete in 3 weeks. In order not to miss a squamous cancer that has invaded deeper than expected, it is important to examine the deep margins of the resected specimen carefully using specialized microscopes like darkfield light microscopes, and to per¬form periodic endoscopic follow-up examinations with vital stain¬ing techniques. This microscopic technique is not appropriate for multiple and widespread or circumferential squamous lesions because of the risk of developing a stricture during the healing process. In this situa¬tion, those acquainted with endoscopic resection would advocate an esophagectomy. (more…)