Photoinactivation of the photosynthetic electron transport chain by accumulation of over-saturating light pulses given to dark adapted pea leaves.

The effect of cumulative over-saturating pulses (OSP) of white light (1 s, >10 000 mumol photons m(-2) s(-1)), applied every 20 min on pea leaves, was investigated during a complete diurnal cycle of 24 h. In dark-adapted leaves, this treatment leads to a progressive decline of the optimum Photosystem II (PS II) quantum yield. Continuous low background light (except far-red light) had a protective effect against this OSP-induced photoinactivation. The lack of far-red effect could be due to its absorption mainly in PS I and not in PS II, but could be also due to the general low absorption in this wavelength region. The photoinactivation was enhanced in leaves that had been previously infiltrated with chloramphenicol. The quantum yield of CO(2) assimilation, but not its maximal capacity, was inhibited by the OSP treatment. The most spectacular effects observed, in addition to an irreversible quenching of Fm, was a strong inhibition of Q(A) (-) reoxidation revealed by a large increase in the Fs level and consequently by a decrease of DeltaF/Fm'. Under such conditions, we observed that the electron flow deduced from DeltaF/Fm' underestimated the real electron flow to CO(2). Time-resolved Chlorophyll a fluorescence measurements showed that the reduced capacity of Q(A) (-) reoxidation in OSP treated leaves was accompanied by the appearance of a 4.7 ns component attributed to PS II charge recombination. We suggest that a modification at the Q(B) site may influence the redox potential of Q(A)/Q(A) (-), facilitating the reversion of the primary charge separation. In addition, a 1.2 ns fluorescence component accumulated, which appeared to be responsible for the underestimation of PS II electron flow. The observed photoinactivation seemed to be different from the photoinhibition often described in the literature, which occurs under continuous light.

[Diagnostic and treatment difficulties in patients with HIV and AIDS infections; the importance of interdisciplinary collaboration]. / Dificultati de diagnostic si tratament la pacientii cu infectie HIV si SIDA; importanta colaborarilor interdisciplinare.

At present, the immunodeficiency syndrome has became pandemic. In these conditions, every doctor, no matter his profile, will have to carry out patients with AIDS. This multisystemic disease goes beyond the limits of a single medical discipline, presenting a lot of clinical manifestations. In ophthalmology, the infection with immunodeficiency virus has a lot of clinical aspects. In the beginning stages, the ocular manifestations are nonspecific, often being the prime symptoms of the general infection. In time, the disease is advancing and the opportunistic infections are becoming very frequent. In the latest stages of the diseases, one can see ocular complications, recurrences of the retinitis and also accidents caused or related with therapy. We have formulated an algorithm of diagnosis, together with some elements of etiology, extremely important for the ocular determinations of the systemic disease. We have presented some general idea about the points, the aim and the principles of the antiretroviral treatment and about the monitoring activity of the disease. We have also presented an algorithm for the initiation of the treatment. As a conclusion, we notice the significance of a close cooperation between doctors, for the diagnostic and also for the therapeutical activity.

[Phacoemulsification and foldable IOL implantation; posterior luxation of the nucleus; delayed phacophagia]. / Facoemulsificare cu implant de pseudofac; luxatie posterioara de nucleu; facofagie amânata.

In the beginning, the paper presents some general words about the main intraoperative complications of the phacoemulsification and some practical attitudes patient in front of the rupture of the posterior capsule. The second part presents the case of a 63 years old patient who was intended to be operated for cataract by phacoemulsification and who suffered a complication during this procedure--the rupture of the posterior capsule with the luxation of the majority of the nucleus into the vitreous body.

[Edematous maculopathy-- a too broad diagnostic "umbrella"?]. / Maculopatia edematoasa--o "umbrela" diagnostica prea larga?

In the beginning, the paper presents some theoretical concepts about the pathological anatomy and the psychopathology of the macular oedema. The next part realizes a systematization of the most important ocular diseases associated with macular oedema, sustained by ophthalmoscopical and fluorescein angiography images. The final part contains the conclusions.

[Difficulties in the diagnosis of glaucoma; the therapeutic implications]. / Dificultati în diagnosticul glaucomului; implicatii terapeutice.

The glaucomatous disease has, the most of time, an insidious beginning; the diagnosis is occasioned by some refraction problems or by a systematic ophthalmological examination or a request coming from another physician. As a consequence, the diagnosis of glaucoma is not always very easy thing, because, in the early stages, the diagnostic criteria rises special problems. Under these conditions, the therapeutical attitude will be differentiated from a case to another. After these general considerations, the authors will discuss some clinical cases, knowing that the diagnosis and the initiation of treatment will give rise to some contradictory discussions.

[The differential diagnosis of a prominent papilla nervi optici--the ophthalmoscopic and angiofluorographic aspects]. / Diagnosticul diferential al papilei proeminente--aspecte oftalmoscopice si angiofluorografice.

In the beginning, the paper presents an up-to-date of the theoretical concepts about the structure, vascularisation, ophthalmoscopical and angiographical appearance of the optic disc. The next part reveals the most important situations in which the optic disc become prominent, sustained by ophthalmoscopic and fluorescein angiographic images. The final part contains the practical conclusions.

[Glaucomatous optic neuropathy. Its etiopathogenetic aspects; the therapeutic consequences]. / Neuropatia optica glaucomatoasa. Aspecte etiopatogenice; implicatii terapeutice.

In recent years, glaucoma is considered a progressive, primitive, intrinsic neuropathy, associated with a disease of the corneoscleral trabeculum. After a short recall of the anatomy and microvascular physiology of the optic nerve, we mention the main etiopathogenic hypothesis, insisting upon the significance of the optic nerve blood flow abnormalities. We discuss then the possible existence of an autoregulation system of blood flow at the level of the optic nerve and the main factors which may be involved in the optic nerve perfusion. In the end, we present some therapeutical consequences, outlining the future expectations.

[Conservative treatment in intraocular tumor in the remaining eye]. / Tratament conservator în tumora intraoculara pe ochi unic.

We present here, the case of a monophtalm patient, with the diagnostic of an intraocular tumour, situation when we have chosen a combination of conservative therapeutically means. Enucleation, as a radical method of treatment, is out of the question. We discuss, by turns, the main alternatives of conservative treatment: sclerochoroido-retinectomy, temporary fixation on the supraiacent sclera of radioactive discs, photocoagulation and cryocoagulation as single methods of treatment, justifying the present option: laser treatment associated with cryocoagulation and immunotherapy. We review some basic concepts of immunology, insisting upon the systemic and topical administration of IL-2. Up to the present, IL-2 is administrated topically only in pulmonary cancer and in cerebral tumours, after the operation, on the excision zones and in cutaneous malignant melanoma, with very good results. In ophthalmology, this is the first therapeutically attempt, using IL-2 in a case of intraocular tumour. The postoperative status and the results on short term put an end to this paper.

[Ultrasonic biomicroscopy in the diagnosis of glaucoma]. / Biomicroscopia ultrasonica în diagnosticul glaucomului.

For the beginning, the authors present a definition of the ultrasound biomicroscopy, together with the main fields of use, instrumentation and examination techniques. The second part of the paper analyses the contribution of the ultrasound biomicroscopy to the diagnosis of the open angle glaucoma and of the angle closure glaucoma. The final part contains some considerations referring to the main ocular diseases in which this technique is already used frequently and the perspectives for the future development of ultrasound biomicroscopy.

[Endocrine exophthalmos]. / Exoftalmia endocrina.

The basedowian exophthalmy is a self-immune originating affection, in which the antigen remains still unknown. It may appear besides the Basedow disease, evoluating in a total independent manner. The clinical diagnosis is done on the basis of small ocular characteristic signs: exopthalmy, oculomotor deficit, optical neuropathy, corneo-conjunctival alterations, being of course supplemented with the complementary endocrinological and immunological explorations. The endocrine exophthalmy represents a serious complication because of the visual risks it implies, and afterwards because of the implied esthetical prejudice. A spontaneous amelioration is possible, but the treatment often proves to be necessary. It will be medical, local and general, and also orbitar radiotherapy and surgical treatment.

[Biometry in cataract surgery with an implant]. / Biometria in operatia de cataracta cu implant.

In cataract surgery, the replacement of the opaque lens with an artificial lens is the ideal correction. For the present, the intraocular lens power determination is an essential part of the preoperative evaluation of an eye. The paper presents a short history about the development of implant power calculation, the main formulas used in present, the precise choice of postoperative refraction, the factors affecting accuracy of implant power calculation and some preoperative considerations (patients considerations, intraocular lens characteristics considerations). The final part contains some conclusions about the methods of implant power calculation.

[Marginal ectasia of the cornea resolved surgically]. / Ectazia marginala a corneei rezolvare chirurgicala.

The paper presents the case of a patient with Terrien's marginal degeneration. The moment of the exam, the corneal degeneration was in an advanced stage, being associated with secondary ectasia. The gutter developed as a results of the stromal progressive thinning was already circumferential. The only efficient treatment in this situation is an annular lamellar keratoplasty. We present the mais operatory moments, and also the main intra- and postoperatory incidents and complications. In spite of the fact that this operative procedure was already mentioned in literature, there are no certain proves; so, we are able to consider the achievement of the annular lamellar keratoplasty unique for this moment.

[The use of prostaglandin compounds in treating glaucoma]. / Utilizarea compusilor prostaglandinici în tratarea glaucomului.

The theoretical part of this paper presents the mechanism of the IOP lowering effect using these drugs, the indications of treatment and the main side effects. The second part consist of the experimental study made on rabbits, using the izopropilic ester of (+)Cloprostenol as an hypotensive agent. We have registered the IOP values and the main side effect--conjunctival hyperemia. The third part consist of the clinical study, made on a test lot of 23 patients. We have used the same substance and in the experimental study, as a unique treatment or in association with a beta-blocker or a pilocarpine derivative. The following-up has implied: the IOP, the ophthalmoscopic appearance of the optic disc, the visual field, the visual acuity and the main side effects. In the end, we have formulated the conclusions of these studies.

[The use of antimetabolites in glaucoma surgery]. / Utilizarea antimetabolitilor în chirurgia glaucomului.

The authors present, in the context of actual management of glaucoma, the role of antimetabolites in addition to glaucoma filtering surgery. The main reason of failure in filtration surgery is the excessive postoperative scarring response at the contact episclera-subconjunctiva. The antimetabolites inhibit the fibroblastic growth, therefore providing a great number of adequate filtering blebs. Indications, surgical techniques, complications and risks are also discussed.

[The immunology of the corneal graft]. / Imunologia grefei de cornee.

In the corneal grafting, the immunological reaction is often existent and although it is mitigated, it still represents a major cause in the keratoplasty's failure. The immunologic privilege of the cornea it's because of the features of the grafting on one hand and because of the features of the receiving cornea, on the other hand, its essential feature being the absence of blood and lymphatic vessels. It might be difficult to distinguish between an allografting reaction and another cause of failure of the keratoplasty. More clinical elements are still reminiscent for an immunological rejection. The incompatibility HLA is theoretically, the main condition of the allografting reaction. But, for several reasons, the typing of HLA isn't done in the majority of keratoplasties. Some preoperative treatments of the grafting tissues reduce the immunological reaction. In order to prevent the rejection, the corticotherapy is widely used today. The A cyclosporine, a new immunomodulator, seems to be a very interesting progress in the therapeutical means.

[The corneal epithelial barrier]. / Bariera epiteliului cornean.

The corneal epithelium is an stratificated pavimentous epithelium. The epithelial cells are grouped in 3 levels: superficial cells, intermediate cells, basal cells. The superficial cells are solidarised by there type of junctional complexes: desmosomes, impermeable junctions, and communicating junctions. Because the corneoconjunctival surface is colonised by microorganisms and every minimal lesions can favorise an infection, the epithelial integrity plays a protective role. The corneal epithelium constitute the main way of intraocular penetration of topical drugs. There are two ways of drugs penetration through corneal epithelium: intracell and pericell way. The penetration speed was influenced by ocular factors (epithelial lesions) and drugs features (solubility, molecular mass, molecular structure, pH, pK, concentration, contact time).

[Color vision in diabetics]. / Vederea culorilor la diabetici.

Color perception is often already altered even if the ocular, anatomic and functional exams maintain their results within the normal limits. This fact is more important in diabetes, where chromatic abnormalities exist at half of the subjects, even if they do not reveal any signs of diabetic retinopathy. The authors present some of the methods in clinical exam of color perception, the characters of dyschromatopsia and glycemic self control using the method of coloured bandelets, types of dyschromatopsia which may appear during the evolution of the diabetes, and also the predictive effect of dyschromatopsia for the appearance of diabetic retinopathy.