[In vitro contractility behavior of portal veins in normal rats and in rats with liver cirrhosis--effect of calcium antagonists and octreotide]

According to Poiseuille's law portal pressure is inversely related to r4. Thus, minor changes in radius dramatically influence intravascular pressure. Since the radius is actively regulated by contraction, this study elucidates in vitro contractility patterns of portal veins from healthy and liver cirrhotic rats. The results demonstrate that contractility amplitudes of portal veins from cirrhotic rats are increased in comparison to healthy animals. Calcium antagonists reduce amplitude and motility both in cirrhotic and healthy rats to the same degree. The same holds true for octreotide but significantly more in the cirrhotic group. Obviously, the maintenance of portal hypertension is supported by an active element of the portal vein, which can be controlled in vitro.

Time course of lectin and storage protein biosynthesis in developing pea (Pisum sativum) seeds

Lectins and storage proteins from pea (Pisum sativum) and other Leguminosae seeds interact in vitro. In order to evaluate whether this relationship may be important also in vivo, the time course of biosynthesis of these proteins in developing pea seeds was followed. The proteins appear in the following temporal order: vicilin-lectin-convicilin-legumin. The time course of protein synthesis was also followed by the subcellular morphological changes occurring simultaneously. The appearance of vicilin coincides with the formation of regularly shaped protein globules within the vacuole. Immediately after the start of lectin synthesis, these globules flatten and begin to adhere to the inner membrane surface of the vacuole. Legumin appears at a time when the vacuoles already have largely disappeared in favour of smaller vesicles which eventually develop into protein bodies. These results together with previous findings are consistent with the view that one of the biological functions of the lectin may consist in serving as a link between vicilin and the inner face of the vacuole membrane.

Computer-assisted orbital surgery

In orbital surgery, deep lesions must be operated on through extremely small approaches. We developed a method (Computer Assisted Surgery or CAS) designed to achieve safer and more precise surgery by providing highly accurate intraoperative information regarding the location of the surgical instrument. The device involved consists of a high-capacity computer that processes computed tomographic (CT) data in real time, connected to a mechanical measuring arm attached to the surgical instrument. From the CT data, the computer calculates a three-dimensional reconstruction and displays the tip of the instrument as a reticle in this model. Using the CAS system, the surgeon is continuously apprised of the precise position of the surgical instrument vis-a-vis all relevant anatomical structures. We have used CAS successfully in 21 cases of orbital surgery. We have found the system especially useful in dealing with deep-seated tumors, either for biopsy or surgery; in performing orbital and optic nerve decompression; in localizing deep-seated foreign bodies; and in all cases of impaired orientation due to severe bleeding, tumor-destroyed landmarks, or preoperated anatomy. Although the number of patients is too small to yield statistically significant data allowing a comparison of patient outcomes with and without using the system, we have just begun a large prospective clinical trial designed to provide such data.

[A new procedure for removal of foreign bodies in the area of the head]

Identification and extraction of penetrating cranial foreign bodies can cause problems in some cases. Small fragments localized deep in the orbit or cerebrum can be especially hard to detect. Severe bleeding and traumatized anatomy can make orientation difficult. We used a new localizing device, computer-assisted surgery (CAS), to good effect in six such cases. CAS is a localizing technique designed to assist the head surgeon during surgery, providing real-time position information. The method is based upon a three-dimensional volume model of the patient's skull generated by preceding computed tomography imaging procedures (CT or MRI). Intraoperative correlation of a 3D-model and the patient's skull allows for real-time position display of a surgical instrument on the monitor screen. Thereby the surgeon is able to localize even small foreign bodies without extensive exploration. In the case of multiple foreign bodies the surgeon calls up a simple documentation facility recording which of the visible fragments have already been extracted. We successfully used the system for extraction of orbital foreign bodies in four and intracerebral foreign bodies in two cases. In a 4-year-old child with gunshot injury the bullet was located in the precentral region and was easily extracted with the CAS system. In a 21-year-old man 39 glass fragments were extracted from the left orbit. In a 36-year-old man a bone fragment was dislocated to the apex of the orbit directly under the optic nerve. Location and extraction were achieved without damage to the orbital structures with the help of the CAS system.

[Value of corticosteroids in after-care of patients after cataract extraction and lens implantation]

In two double-blind controlled trials the anti-inflammatory effects of dexamethasone were examined in post-cataract extraction eyes after lens implantation in 321 patients. In the first trial, 103 patients were included. 49 eyes received eye-drops with 0.1% dexamethasone and antibiotics, the control-group of 54 eyes received the same antibiotics without any steroids. The follow-up was 2 months. In the case of unexpected complications, the patients dropped out. This was the case in 48% of the steroid-group and in 79% of the control-group. The main reason for this statistically significant difference were inflammatory complications in the control-group, which are difficult to quantify. The incidence of fibrinous reactions was not significantly different in the two groups, probably because of small numbers. In the second trial, we looked for fibrinous reactions. The follow-up was 3 weeks, 218 patients participated. They were divided into three groups: 71 patients received eyedrops with 0.1% dexamethasone 4x daily, 77 patients received the same drops 4x daily up to the fifth postoperative day, from then on 1x daily. 70 patients received the same drops 1x daily. A mild fibrinous reaction was seen in 10% of the high-dose-group, in 6% of the medium-dose-group and in 21% of the low-dose-group. Only the difference between the last two groups is statistically significant. We conclude that the therapy with corticosteroids after cataract extraction and lens implantation may be reduced early in the postoperative course.

Electrophysiological and morphological changes in rabbit retina after exposure to the light of the operating microscope

Healthy adult rabbit eyes were exposed to up to 4 h of continuous illumination with moderate light intensity, as is produced by the lamp of an ophthalmic operating microscope. Electroretinograms were recorded before and after the long period of illumination. The depression of the waves in the electroretinograms observed just following light exposure recovered within 1 h to normal values. Electron microscopy of the retina revealed changes within the cells of the pigment epithelium. These results are discussed in view of their clinical implications in human patients.

Scanning electron microscopic and energy-dispersive X-ray analysis findings on two brand new intraocular lenses

Two intraocular lenses (IOLs) from the same manufacturer showed surface particles by scanning electron microscopy. With energy-dispersive X-ray analysis, these were shown to contain Mg-Si, Al-Mg-Si, Ti, Fe, Ca and Cu. A sterile chronic intraocular inflammation may result from implantation of such contaminated IOLs.

Aortocoronary vascular prosthesis made of siliconized homologous vein or bovine sacral artery

The purpose of our study was to develop and prepare aortocoronary prostheses, test them experimentally in multivascular and coronary reoperations in case of missing autologous grafts and to use them for shunt operations in cardiac surgery. Human vein or bovine sacral artery were used for preparing aortocoronary prostheses. As for metrics of 9-14 Charr. and a length of 20-30 cm were obtained. Aortocoronary prostheses were preformed according to the coronary configuration for left descending artery, circumflex artery and right coronary artery. Aortocoronary prostheses meet the conditions of desantigenicity, sterility, athrombogenicity, tightness and high tensile strength, tear propagation strength, bursting pressure and shrinkage temperature. Experimental testing was performed in dogs in aortofemoral and aortocoronary positions. Infections did not occur. The healing process and structural changes of aortocoronary vascular prostheses (grafts) were examined histologically and evaluated by means of scanning electron microscopic examinations. Athrombogenicity and healing-in without inflammation and calcification were proved.

Schweres Wasser (D2O) als Protektivum proteinhaltiger Arzneimittel. Beispiel: humane Cholinesterase/Protein Drugs Stabilized by Heavy Water (D2O). For Example: Human Cholinesterase

Looking for a possible protective effect of heavy water on proteins, cholinesterase and lac­tate dehydrogenase in combination with D2O and further protective substances were exposed to a temperature of 60 °C (for 10 min) and about 45 °C (for several days). In combination with glycerine there resulted an additive protective effect; with NaCl and/or albumin being added the individual effects raised to a higher level. In the cold D2O protects cholinesterase only against acid denaturation, but in combination with warmth also against basic denaturation.

AGN 190383, a novel phospholipase inhibitor with topical anti-inflammatory activity

AGN 190383 is a 5-hydroxy-2(5H)-furanone ring analog of the marine natural product manoalide. When applied topically, AGN 190383 inhibits phorbol ester induced mouse ear edema. It is a potent inhibitor of bee venom phospholipase A2 and blocks the release of arachidonic acid from calcium ionophore A23187 stimulated human neutrophils. AGN 190383 also inhibits both hormone-operated and depolarization-dependent calcium mobilization in GH3 cells, as well as fMLP stimulated increases in free cytosolic calcium in human PMNs. Furthermore, it is also able to block the release of the neutral protease elastase from stimulated neutrophils. The effects of AGN 190383 on arachidonic acid metabolism and leukocyte function may account, in part, for its anti-inflammatory activity in vivo.

[Heavy water (D2O) as a protective protein containing medium. Example: human cholinesterase]

Looking for a possible protective effect of heavy water on proteins, cholinesterase and lactate dehydrogenase in combination with D2O and further protective substances were exposed to a temperature of 60 degrees C (for 10 min) and about 45 degrees C (for several days). In combination with glycerine there resulted an additive protective effect; with NaCl and/or albumin being added the individual effects raised to a higher level. In the cold D2O protects cholinesterase only against acid denaturation, but in combination with warmth also against basic denaturation.

An alternative to 'two-step' tuberculin skin testing for Southeast Asian refugees

Previous studies report that Southeast Asian refugees demonstrate very high incidences of positive reactions to two-step tuberculin testing. In spite of these findings, fiscal restraints have limited the use of two-step testing in some of the centers that screen large numbers of these refugees. In this study, 101 Southeast Asian refugees were studied for their antigenic response to the tuberculin skin test. Forty-nine had positive reactions when the tuberculin skin test was read at 48 hours. Of the 52 refugees who showed a negative reaction at 48 hours, 22 had positive reactions when read a second time, three to five days later. The 28 refugees with negative reactions at both 48 hours and at five to seven days underwent two-step tuberculin testing. Only two of the 28 demonstrated positive reactions with two-step testing. Of the refugees with positive reactions at 48 hours, all but one continued to show positive reactions when the skin test was read a second time, at five to seven days. These findings suggest that a single tuberculin skin test, read at five to seven days, may provide a cost-effective alternative to two-step tuberculin testing for Southeast Asian refugees.

Cellular reactions on heparin surface-modified versus regular PMMA lenses during the first postoperative month. A double-masked and randomized study using specular microphotography

Specular microscopy was used for investigation of cellular reactions on the intraocular lens (IOL) anterior surface of Heparin surface-modified (HSM) versus regular polymethylmethacrylate (PMMA) lenses (Pharmacia types 700C versus 700B, respectively). The double-masked randomized study included 53 patients investigated at 1 and 4 weeks postoperatively. Giant cells were only found on control lenses and more frequently at 4 weeks. Small cells were found on both lens types, but in a higher frequency on the control lenses. The number of small cells decreased during the first 4 weeks on both the control and HSM lenses. However, those control lenses that had giant cells on their surface showed an increase in the number of small cells during the same time. The results of the current study show that HSM lenses give rise to less postoperative inflammatory cellular reactions than regular PMMA lenses.

[Iritis following cataract operations. Historical retrospective with critical comments on a so-called "toxic lens" syndrome]

Postoperative inflammation is one of the oldest complications of cataract surgery. It was described by the Indian Susruta as early as 500 BC. Following the introduction of cataract extraction by Daviel in 1745, these operations attracted increasing interest. In 1786 de Wenzel distinguished two types of postoperative inflammation. In the dangerous type there was involvement of the entire eye and severe pain; in the benign type, which began in the first few postoperative days, the conjunctiva and lids were not involved, and even if hypopyon developed there was no severe pain. During the 19th century, the possible causes of the benign type of iritis were discussed, including infection, phacoanaphylaxis, trauma, toxicity of irrigation solutions etc. In the early days of implantation of intraocular lenses, from 1949 onward, postoperative inflammation was common. However, it was not until 1980 that the term "toxic lens syndrome" was introduced. The clinical descriptions do not differ much from other descriptions of benign iritis published during the last 200 years. Therefore, it does not seem that there is any great advantage to be gained by using this new term.