DIAGNOSIS AND TREATMENT OF GLAUCOMA—A Review of Recent Developments

Tonography is helpful in the diagnosis of doubtful cases of chronic simple glaucoma. If also gives a good indication of the status of the disease in a given eye.The most useful miotic in the treatment of glaucoma is still pilocarpine. Carbachol is more potent but must be used in an anhydrous base ointment or in a solution of a wetting agent. DFP (diisopropyl fluorophosphate) produces undesirable side effects because of the hyperreactivity of the ciliary body and iris sphincter which it causes. These can be partly overcome by using pilocarpine first. Diamox is a carbonic anhydrase inhibitor that is effective when given orally. In many cases it produces at least a temporary lowering of tension in glaucomatous eyes, apparently by reducing the secretion of intraocular fluid. Its ultimate value in glaucoma remains to be seen.The cyclodiathermy operation which has been modified somewhat by Weekers has had a recent increase in use but the long-term results have been somewhat disappointing.The importance of early operation in narrow angle glaucoma is becoming more and more apparent. Following iridectomy the wound should be tightly sutured to insure the prompt reformation of the anterior chamber.     

Efficient sorting of genomic permutations by translocation, inversion and block interchange

MOTIVATION: Finding genomic distance based on gene order is a classic problem in genome rearrangements. Efficient exact algorithms for genomic distances based on inversions and/or translocations have been found but are complicated by special cases, rare in simulations and empirical data. We seek a universal operation underlying a more inclusive set of evolutionary operations and yielding a tractable genomic distance with simple mathematical form. RESULTS: We study a universal double-cut-and-join operation that accounts for inversions, translocations, fissions and fusions, but also produces circular intermediates which can be reabsorbed. The genomic distance, computable in linear time, is given by the number of breakpoints minus the number of cycles (b-c) in the comparison graph of the two genomes; the number of hurdles does not enter into it. Without changing the formula, we can replace generation and re-absorption of a circular intermediate by a generalized transposition, equivalent to a block interchange, with weight two. Our simple algorithm converts one multi-linear chromosome genome to another in the minimum distance.     

Cell suspension as a tool to study the biosynthesis of pilocarpine in Jaborandi

Jaborandi (Pilocarpus microphyllus) is a species that naturally occurs in the North and Northeast of Brazil, whose leaves produce pilocarpine (an imidazole alkaloid that has been used to treat glaucoma and xerostomy), the biosynthesis of which is still uncertain. The aim of this work was to establish cell lineages and select them according to an alkaloid profile similar to the one from Jaborandi leaves. The induction of callus was done in different culture media and growth regulators. Calluses from primary cultures or those subcultured several times were used as explants for the obtainment of six cell lineages. Alkaloids content analyses and growth curves showed that lines obtained from primary cultures produced more alkaloids and a better development. Cell lines from 12 subcultures presented a decrease in pilocarpine and pilosine production. After 24 subcultures, the production of alkaloids remained constant. ESI-MS analysis showed that cell culture extracts have the same alkaloid composition as extracts made from leaves. The results indicate that cell suspensions can be used as a model to study the biosynthesis of the imidazole alkaloid in P. microphyllus.     

Exploring the potential for subtype-selective muscarinic agonists in glaucoma

Pilocarpine has been used to lower intraocular pressure (IOP) in glaucoma patients for more than 100 years. Since the identification of five muscarinic receptor subtypes, there has been an interest in separating the IOP-lowering effects from the ocular side effects of pupil constriction and lens accommodation. However, all these actions seem to be mediated by the M3 receptor. A novel muscarinic receptor agonist, AGN 199170, that has no activity on the M3 subtype was compared to pilocarpine in a monkey glaucoma model. This compound lowered IOP suggesting that muscarinic agonists targeted at muscarinic receptors other than the M3 subtype may be able to selectively lower IOP.     

Corneal thickness in congenital glaucoma

Central corneal thickness is very important measurement in glaucoma treatment because it influences the eye pressure measurements. A thinner cornea gives us artifactually lower intraocular pressure and a thicker cornea gives higher intraocular pressure reading, so it has to be corrected in both cases. The aim of this study is to compare central corneal thickness between congenital glaucoma patients and normal subjects. Prospective study included 27 patients with congenital glaucoma and 35 patients in control group. First group was subdivided in two subgroups: A--8 earlier operated patients, B--19 patients treated with topic therapy. Patients had no other corneal disorders, history of trauma, corneal surgery and they were not contact lens wearers. Measurements were performed by specular microscope Tomey EM 3000 on central corneas. This study showed that patients with congenital glaucoma have lower central corneal thickness than normal subjects. Also, the study showed that antiglaucomatous operation doesn't influence central corneal thickness. Central corneal thickness need to be a routine part of examination measurements because of need to correct intraocular pressure according to it, but also the thinner corneas values can suggest congenital glaucoma diagnosis beside the other parameters.     

Pilocarpine Protects Cobalt Chloride-induced Apoptosis of RGC-5 Cells: Involvement of Muscarinic Receptors and HIF-1α Pathway

The retina is the most metabolically active tissue in the human body and hypoxia-induced retinal ganglion cell (RGC) death has been implicated in glaucomatous optic neuropathy. The aim of this study is to determine whether muscarinic receptor agonist pilocarpine, a classic antiglaucoma drug, possesses neuroprotection against cobalt chloride (CoCl₂)-mimetic hypoxia-induced apoptosis of rat retinal ganglion cells (RGC-5 cells) and its underlying mechanisms. Cell viability was determined by Cell Counting Kit-8 assay and apoptosis was examined by annexin V and mitochondrial membrane potential (MMP) assays. Expressions of hypoxia-induced factor-1α (HIF-1α), p53, and BNIP3 were investigated by quantitative real-time PCR and western blot analysis. After treatment of 200 μM CoCl₂ for 24 h, RGC-5 cells showed a marked decrease of cell viability by approximately 30%, increased apoptosis rate and obvious decline in MMP, which could largely be reversed by the pretreatment of 1 μM pilocarpine mainly via the activation of muscarinic receptors. Meanwhile, pretreatment of 1 μM pilocarpine could significantly prevent CoCl₂-induced HIF-1α translocation from cytoplasm to nucleus and down-regulate the expression of HIF-1α, p53, and BNIP3. These studies demonstrated that pilocarpine had effective protection against hypoxia-induced apoptosis in RGCs via muscarinic receptors and HIF-1α pathway. The findings suggest that HIF-1α pathway as a “master switch” may be used as a therapeutic target in the cholinergic treatment of glaucoma.     

EPINEPHRINE HAND NEBULIZER IN ASTHMA—Technique of Use,Clinical Aspects

It behooves the physician seeking relief for asthmatic patients not to be casual about the epinephrine hand nebulizer and the manner in which it is used. Patients who claim to get no relief from the nebulizer should be asked to demonstrate their technique. If the nebulizer produces a hardly visible mist, it should be discarded. For many patients, the goal in spraying by hand must be the production of more or less continuous and voluminous aerosol, regardless of the phase of respiration, in order to effect relief. If the respiratory pattern has not deviated too far from normal in rate and depth, inhalations may be carried out in courses or cycles of about a half-minute duration and spaced a few minutes apart. If the respiratory pattern is abnormal during the act of spraying, it must be corrected.Inhaled epinephrine aerosols as constituted today appear to be somewhat irritating to the mouth, throat, and upper portion of the pulmonary tract of some persons, but it has not been convincingly demonstrated that serious and permanent damage to the lower respiratory tract of humans can occur from long-continued use of inhaled epinephrine.     

Epinephrine hand nebulizer in asthma; technique of use,clinical aspects

It behooves the physician seeking relief for asthmatic patients not to be casual about the epinephrine hand nebulizer and the manner in which it is used. Patients who claim to get no relief from the nebulizer should be asked to demonstrate their technique. If the nebulizer produces a hardly visible mist, it should be discarded. For many patients, the goal in spraying by hand must be the production of more or less continuous and voluminous aerosol, regardless of the phase of respiration, in order to effect relief. If the respiratory pattern has not deviated too far from normal in rate and depth, inhalations may be carried out in courses or cycles of about a half-minute duration and spaced a few minutes apart. If the respiratory pattern is abnormal during the act of spraying, it must be corrected. Inhaled epinephrine aerosols as constituted today appear to be somewhat irritating to the mouth, throat, and upper portion of the pulmonary tract of some persons, but it has not been convincingly demonstrated that serious and permanent damage to the lower respiratory tract of humans can occur from long-continued use of inhaled epinephrine.     

Improving medication compliance: a randomised clinical trial.

A medical monitor which recorded the date and hour each time a medicine bottle was opened was used to evaluate a programme for improving patients'' compliance with their treatment. Eighty-two patients with glaucoma who had been prescribed pilocarpine eye drops three times daily to prevent visual loss were randomised into two groups. Both groups used the medication monitor during two 20-day periods, but before the second period the experimental group were given an education and tailoring programme in an attempt to improve their compliance. Nine patients missed the second treatment period and were excluded from the analysis. The patients in the experimental group showed significantly improved compliance when compared with the control group. The numbers of missed doses were reduced by about half, as was the proportion of time that exceeded the eight-hour dose intervals. Follow-up studies are needed to determine how long the improved compliance persists, but anyone considering setting up an education and tailoring programme should recognise the extent to which therapeutic efforts are wasted because of non-compliance.     

D-1 dopamine agonist administration reduces the threshold for convulsions produced by pilocarpine

Focal, limbic seizures were produced by systemically administered pilocarpine (200 mg/kg, i.p.); as previously described this dose produces limbic stereotypies but neither convulsions nor seizure-related brain damage. The pretreatment, 5 minutes prior pilocarpine, with the D-1 agonist SKF 38393 (-ED50 = 1 mg/kg; i.p.) induced convulsions similar to those produced by a higher, convulsant dose of pilocarpine. On the other hand, the pretreatment with the D-2 agonist LY 171555 failed to induce convulsions. The D-1 receptor antagonist SCH 23390 prevented the convulsions induced by SKF 38393 plus pilocarpine (200 mg/kg). This study indicates that D-1, but not D-2, receptor stimulation converts subconvulsant doses of pilocarpine into convulsant ones.     

Salivary gland-sparing prophylactic pilocarpine treatment has no effect on tumor regrowth after irradiation

Radiotherapy of head and neck cancer frequently damages the salivary glands. Prophylactic administration of the muscarinic receptor agonist pilocarpine reduces subsequent radiation damage to the salivary glands in rats, but its effects on tumor cell radiosensitivity and tumor regrowth after irradiation had not been assessed. In the current study, we first tested the effect of pilocarpine on clonogenic cell survival in vitro. No effect of pilocarpine on radiosensitivity was observed in a panel of cell lines either with or without expression of muscarinic receptors. Second, a single dose of pilocarpine known to protect salivary gland tissue from radiation damage was given to rats transplanted with subcutaneously growing rhabdomyosarcomas 1 h prior to irradiation with a single dose of 35 Gy. No alterations in growth delay were detected (26 +/- 2 days for controls compared to 26 +/- 2 days for pilocarpine treatment). Our data indicate that pilocarpine pretreatment, which has been shown previously to protect salivary glands from radiation, does not protect tumor cells or tumors. Use of this drug therefore may lead to therapeutic gain in the treatment of head and neck cancer.     

INDICATIONS FOR OPERATION IN GLAUCOMA

Prompt surgical operation is indicated in angle-closure glaucoma and in infantile glaucoma. Open-angle glaucoma is properly considered a disease for which conservative treatment should be tried.Operation is indicated in open-angle glaucoma when, despite maximal medical therapy, the intraocular pressure reaches a level at which the optic nerve is going to be damaged. Many factors must be considered in making a decision as to whether or not to operate in such circumstances, among them the condition of the eye, the result of previous operation if one has been done, the reliability of the patient with regard to carrying out a prescribed regimen, the age and physical condition of the patient, perhaps the race of the patient, the presence of cataracts and the attitude of both patient and surgeon toward surgical treatment.     

On the predictive power of numerical and Braun-Blanquet classification: an example from beechwoods

Abstract. A numerical classification method and the Braun-Blanquet method, based on external criteria, were compared with the aim of clarifying the differences in predictive power. The numerical analysis leads to a changed perspective on the floristic data and produces, as a whole, an ecologically more differentiated classification. The groups produced by numerical analysis are almost identical with the Braun-Blanquet classification with respect to marginal site conditions but they may differ in cases of intermediate site conditions. Nevertheless, a classification emerges which is on the whole, both floristically and as to site, very similar to the Braun-Blanquet classification. The discriminatory importance of the external variables is, to a large extent, the same in both methods, but discriminant analysis shows that the numerical classification is somewhat more predictive.     

ACUTE APPENDICITIS COMPLICATING PREGNANCY

Acute appendicitis occurs as a complication of pregnancy in about 0.1 per cent of cases. Diagnosis may be somewhat more difficult during the second and third trimesters dur to the displacement of viscera and the increased incidence of pyelitis and constipation. It is based on the same symptoms and signs as in nonpregnant patients.The treatment is immediate operation regardless of the stage of pregnancy. A McBurney incision is preferred and it is placed somewhat higher than usual in the later stages of pregnancy. When operation is done promptly there is little danger to either mother or fetus.     

Mucus-glycoproteins (mucins) of the cat trachea: characterisation and control of secretion

Glycoproteins produced by the tracheae of anaesthetized cats were radiolabelled biosynthetically by a pulse administration of Na2 35SO4 and [3H]glucose into the tracheal lumen. Subsequently, radiolabelled secretions were washed from the tracheal lumen. Repeated doses of pilocarpine and then ammonia vapour were given to stimulate secretion. Pilocarpine-stimulated glycoproteins, which came mainly from the submucosal glands, were particularly enriched with 35S. Ammonia-stimulated secretions, which probably came mostly from the microvillous border of the surface epithelium, contained mainly 3H radioactivity but little 35S. Two negatively-charged glycoproteins of different molecular size were identified in the secretions: the larger component was excluded on Sepharose CL-4B and it had a higher 3H 35S ratio than the smaller component which was retarded on Sepharose CL-4B. The relative amount of the smaller component decreased progressively with repeated pilocarpine stimulation and it was not detected in secretions induced by ammonia. Pilocarpine stimulation caused little alteration in carbohydrate composition of the secreted glycoproteins. In response to ammonia, glycoproteins were secreted with a high sialic acid content but quantitatively they represented a small amount of material compared with that induced by pilocarpine. These findings suggest that tracheal glycoproteins from different epithelial-cell sources have distinctive chemical compositions and that their secretions may be independently regulated. The 35S-rich high-molecular-weight glycoproteins from the submucosal glands were of the mucin-type but those derived from the microvillus border may represent a different class of airway glycoproteins from typical epithelial mucins.     

CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM : II. THE ACTION OF GUAIACOL AS AFFECTED BY pH

The normal P.D. across the protoplasm of Valonia macrophysa is about 10 mv. negative (inwardly directed). On adding 0.01 M guaiacol to the sea water the P.D. becomes positive and then slowly returns approximately to the normal value. In many cases this behavior is not much affected by raising the pH and so increasing the concentration of the guaiacol ion but in other cases such an increase makes the P.D. somewhat more negative. But if we wait until the exposure to guaiacol has lasted 5 minutes (and the P.D. has returned to its normal value) before we raise the pH, the result is very different. The cell then behaves as though it had been sensitized to the action of the guaiacol ion which appears to be far more effective than undissociated guaiacol in making the P.D. more positive. This may be due in part to the high apparent mobility of the guaiacol ion and in part to alterations which it produces in the protoplasm (such alterations increase the P.D. across the protoplasm whereas ordinary injury would be expected to lower it and the cells live on after this treatment and show no signs of injury). This action of the guaiacol ion is in marked contrast to the behavior of other anions whose effect resembles that of Cl^-.     

Further studies on the effect of cimetidine and other neurotropic drugs on rat serum prolactin

The hyperprolactinemic effect of H2 histamine receptor antagonists has been described in the rat and in humans. The present study was undertaken to explore more fully the hyperprolactinemic action of cimetidine, and its interrelationship with other neurotropic agents. Adult ovariectomized estrogen-primed rats were injected with mepiramine, diphenhydramine, pilocarpine, atropine, dopamine, cimetidine or saline as control, at different sequences and the effect on serum prolactin was determined. The effect of cimetidine on prolactin release "in vitro" by hemipituitaries of estrogenized male rats during a short time incubation period, was also investigated. Our results indicate that cimetidine is able to release prolactin and that this effect is not prevented by atropine or the classical antihistaminergic agents mepiramine and diphenhydramine. Both pilocarpine and dopamine inhibit the prolactin release due to cimetidine. The hypoprolactinemic action of pilocarpine was completely blocked by atropine, but not by mepiramine or diphenhydramine. Finally, cimetidine was unable to modify significantly the prolactin release by incubated pituitaries. It is postulated that cimetidine acts mainly at the brain and that the hyperprolactinemic effect is not mediated by muscarinic or H1 histaminergic receptors. This action can be prevented by drugs such as dopamine that are able to act on the lactotroph, and also by pilocarpine, probably by stimulating a prolactin inhibiting pathway.     

Pentachlorophenol

Pentachlorophenol (PCP) is a substance whose widespread use, mainly in wood protection and pulp and paper mills, has led to a substantial environmental contamination. This in turn accounts for a significant exposure of the general human population, with rather high exposure levels being attained in occupational settings.Investigations on the genotoxic activity of PCP have given rise to divergent results which would seem to make an evaluation difficult. By grouping them into 3 categories a somewhat clearer picture, allowing finally an (admittedly tentative) assessment, can be obtained.PCP does seem to be at most a weak inducer of DNA damage: it produces neither DNA-strand breaks nor clear differential toxicity to bacteria in rec-assays in the absence of metabolic activation. Also in SCE induction no increase can be observed in vivo, while PCP is found marginally active in a single in vitro experiment. Metabolic activation, however, leads to prophage induction and to DNA strand breaks in. human lymphocytes, presumably through the formation of oxygen radicals. A possible further exception in this area might be the positive results in the yeast recombination tests, although their inadequate reporting makes a full evaluation difficult.PCP does not seem to induce gene (point) mutations, as most bacterial assays, the Drosophila sex-linked recessive lethal test and in vitro assays with mammalian cells did not demonstrate any effects. Marginally positive results were obtained in the mammalian spot test in vivo and in one bacterial test; the positive result in the yeast assay for cycloheximide resistance is fraught somewhat with its questionable genetic basis.PCP does, however, induce chromosomal aberrations in mammalian cells in vitro and in lymphocytes of exposed persons in vivo. Those in vivo results that were unable to provide evidence of chromosomal damage are hampered either by methodological inadequacies or by too low exposure levels.The (rodent) metabolite tetrachlorohydroquinone might be a real genotoxic agent, capable of binding to DNA and producing DNA strand breaks; this activity is probably due to semiquinone radical formation and partly mediated through active oxygen species. Since this compound has not been tested in the common bacterial and mammalian mutagenicity assays, the few ancillary results on this substance cannot be used in a meaningful human risk assessment of PCP. Furthermore, this metabolite has only been produced by human liver microsomes in vitro, but has not been detected in exposed humans in vivo. Its formation in mutagenicity test systems and its activity involving radicals might, however, help to explain some of the divergencies in the genotoxicity results.The review concludes that PCP is a weak human clastogen which may lack other genotoxic properties, although it may add somewhat to the normal oxidative damage.     

Differences in sensitivity to the convulsant pilocarpine in substrains and sublines of C57BL/6 mice

In rodents, the cholinomimetic convulsant pilocarpine is widely used to induce status epilepticus (SE), followed by hippocampal damage and spontaneous recurrent seizures, resembling temporal lobe epilepsy. This model has initially been described in rats, but is increasingly used in mice, including the C57BL/6 (B6) inbred strain. In the present study, we compared the effects of pilocarpine in three B6 substrains (B6JOla, B6NHsd and B6NCrl) that were previously reported to differ in several behavioral and genetic aspects. In B6JOla and B6NHsd, only a small percentage of mice developed SE independently of whether pilocarpine was administered at high bolus doses or with a ramping up dosing protocol, but mortality was high. The reverse was true in B6NCrl, in which a high percentage of mice developed SE, but mortality was much lower compared to the other substrains. However, in subsequent experiments with B6NCrl mice, striking differences in SE induction and mortality were found in sublines of this substrain coming from different barrier rooms of the same vendor. In B6NCrl from Barrier #8, administration of pilocarpine resulted in a high percentage of mice developing SE, but mortality was low, whereas the opposite was found in B6NCrl mice from four other barriers of the same vendor. The analysis of F1 mice from a cross of female Barrier 8 pilocarpine‐susceptible mice with resistant male mice from another barrier (#9) revealed that F1 male mice were significantly more sensitive to pilocarpine than the resistant parental male mice whereas female F1 mice were not significantly different from resistant Barrier 9 females. These observations strongly indicate X‐chromosome linked genetic variation as the cause of the observed phenotypic alterations. To our knowledge, this is the first report which demonstrates that not only the specific B6 substrain but also sublines derived from the same substrain may markedly differ in their response to convulsants such as pilocarpine. As the described differences have a genetic basis, they offer a unique opportunity to identify the genes and pathways involved and contribute to a better understanding of the underlying molecular mechanisms of seizure susceptibility.