Chronic obstructive pulmonary disease with tracheostomy: report of case involving endodontic treatment

Modern medicine has made many advances in the capability to sustain life. The dental profession needs to keep up to date with these changes and be creative in caring for these individuals who are medically compromised and who require special care.¹¹ This sometimes requires the purchase of new equipment; other times it means modifying that which exists. In all instances, the level of care for these individuals requires a team approach and mandates education of all team members. In the case presented, the medical problems necessitated such a team effort to achieve optimal care.     

Interferon Alfa-2b or Not 2b? Significant Differences Exist in the Decision-Making Process between Melanoma Patients Who Accept or Decline High-Dose Adjuvant Interferon Alfa-2b Treatment

BACKGROUND: Patients with thick (Breslow>4 mm) primary melanoma and/or regional nodal metastasis have a high risk of tumor recurrence. High-dose adjuvant interferon (IFN) alfa-2b offers/=50% risk of recurrence/disease-related mortality and offered IFN. Telephone surveys delineated reasons behind patients' decisions to accept IFN. RESULTS: Acceptors, 60 of 135 (45%), decided to take IFN alfa-2b whereas 75 of 135 (55%) declined. Being female (OR, 2.4; 95% CI, 1.17-5.03; p=.017) and positive SLN status (OR, 2.2; 95% CI, 1.01-4.97; p=.048) were strongly associated with patients who chose IFN. Acceptors of IFN were younger, more influenced by physicians, and less affected by depression and side effect profile (p<.05 for all). Decliners were more concerned by strained relationships with family and social life (p<.05). CONCLUSIONS: Gender and positive SLN were predictive of high-risk melanoma patients' acceptance of IFN treatment. Physician insight into melanoma patients' therapeutic decision-making process can guide patients through this difficult disease.     

Effects of Glycerol on Lung and Liver Tumor Development

Mice of several strains(A/J, SWR, MaMyJ, BALB/cByJ, 129J, andC57BL/6J) were treated with the carcinogens 3-methylcholanthrene,urethane, and 4-nitroquinoline 1 -oxide and then given 1 or5% glycerol in the drinking water for up to 4 months. Effectsof glycerol on lung tumor multiplicity and incidence were evaluated.The effects of glycerol were variable, and in the majority ofexperiments glycerol failed to enhance tumor development inmouse lung. Analysis of cell kinetics did not show a proliferativeresponse of alveolar or bronchiolar cells to glycerol. In rats,glycerol did not enhance the appearance of putative preneoplasticliver foci, and in C3H mice it did not increase the incidenceof spontaneously occurring liver tumors. It is concluded thatglycerol does not increase number or incidence of lung tumorsin the mouse strains used, whether the animals are pretreatedwith a carcinogen or not. Glycerol does not affect liver tumordevelopment.     

EVALUATION OF THE SELECTIVITY OF α-ADRENORECEPTOR BLOCKING DRUGS FOR POSTSYNAPTIC α1- AND α2-ADRENORECEPTORS IN A SIMPLE ANIMAL MODEL

• 1 The increase in diastolic pressure of pithed, normotensive rats was determined after i.v. administration of the α-adrenoreceptor agonists L-phenylephrine and B-HT 933.
• 2 α-Adrenoreceptor antagonists varied widely in their relative inhibitory effects towards either L-phenylephrine- or B-HT 933-induced vasoconstrictor responses. Prazosin displayed the highest affinity for the postsynaptic α-adrenoreceptor triggered by L-phenylephrine. The rank order of potency was further: phentolamine > dihydroergotamine > clozapine > corynanthine > azapetine > yohimbine > piperoxan > tolazoline > mianserin > rauwolscine. On the other hand, the rank order of potency towards B-HT 933 was: dihydroergotamine > rauwolscine > yohimbine > phentolamine > piperoxan > prazosin > tolazoline > mianserin > corynanthine > azapetine > clozapine. These data are in general agreement with the classification for α1-(triggered by L-phenylephrine) and α2-(triggered by B-HT 933) adrenoreceptors. Both populations are present postsynaptically in vascular smooth muscle of the pithed rat and are involved in vasoconstriction.
• 3 The ratio of K_B post α2/K_B post α1 was calculated as a measure of selectivity for either α-adrenoreceptor site. The α-adrenoreceptor antagonists used cover a 20,000-fold range of activity ratios. The antagonists most selective for either type were prazosin (α1) and rauwolscine (α2). The selectivity of the α-adrenoreceptor antagonists for postsynaptic α1- and α2-adrenoreceptors in the intact circulatory system of the pithed rat is comparable with the reported selectivity of these blocking agents for α1 (postsynaptic)- and α2 (presynaptic)-adrenoreceptors in the rabbit isolated pulmonary artery.
• 4 It is concluded that two distinct types of postsynaptic α-adrenoreceptors participate in vasoconstriction in the pithed rat. Apart from the classical α1-adrenoreceptor, vascular smooth muscle of the pithed rat contains postsynaptic α2-adrenoreceptors resembling those previously found mainly presynaptically. The presence of separate classes of postsynaptic α1- and α2-adrenoreceptors in the intact circulatory system of the pithed rat offers the possibility to use this relatively simple animal model as an in vivo test system for the pharmacological characterization of α-adrenoreceptor agonists and antagonists.

     

FUNCTIONAL ROLE OF CARDIAC PRESYNAPTIC α2-ADRENORECEPTORS IN THE BRADYCARDIA OF α-ADRENORECEPTOR AGONISTS IN PENTOBARBITONE- AND URETHANE-ANAESTHETIZED NORMOTENSIVE RATS

• 1 The relative potencies of 6 α-adrenoreceptor agonists, with differing physicochemical properties, at cardiac presynaptic α-adrenoreceptors were determined by measuring their ability to reduce the tachycardia produced by stimulation of the cardiac sympathetic nerves in pithed rats. The compounds studied were clonidine, B-HT 933 (azepexole), oxymetazoline, St 91, naphazoline and DPI.
• 2 The bradycardia produced by the same compounds in bilaterally vagotomized, urethane- or pento-barbitone-anaesthetized normotensive rats were also compared. The relative order of presynaptic potency appeared similar to that observed for the bradycardic activity of the compounds in urethane- and pento-barbitone-anaesthetized rats. In pentobarbitone-anaesthetized rats all compounds evoked a maximal effect of 18–20% reduction in heart rate. In urethane-anaesthetized rats, however, a difference was observed between clonidine and azepexole on the one hand and oxymetazoline, St 91, naphazoline and DPI on the other hand. The former induced a 20–22% reduction in cardiac frequency, whereas the latter diminished heart rate by 10–16% only. In vagotomized, bilaterally adrenalectomized, urethane-anaesthetized rats, clonidine, St 91, naphazoline and azepexole evoked a 25% reduction in heart rate, whereas a 20% reduction was observed for DPI and oxymetazoline.
• 3 A radio-enzymatic determination of plasma catecholamines demonstrated that under urethane-anaesthesia plasma adrenaline concentrations were significantly elevated over the values observed in pentobarbitone-anaesthetized rats. This rise in plasma adrenaline was related to the amount of urethane used. In urethane-anaesthetized, bilaterally adrenalectomized rats, plasma adrenaline was not significantly elevated.
• 4 These findings demonstrate the involvement of cardiac presynaptic α₂-adrenoreceptors in the acute bradycardia, evoked by the α-adrenoreceptor agonist upon intravenous application to pentobarbitone-anaesthetized, normotensive rats. In urethane-anaesthetized rats, however, the functional role of the cardiac presynaptic α₂-adrenoreceptors may be obscured as a result of the high plasma adrenaline levels observed in these animals.

     

IMPAIRMENT BY NIFEDIPINE OF VASOPRESSOR RESPONSES TO STIMULATION OF POSTSYNAPTIC α2-ADRENORECEPTORS IN GANGLION-BLOCKED RABBITS. FURTHER EVIDENCE FOR THE SELECTIVE INHIBITION OF POSTSYNAPTIC α2-ADRENORECEPTOR-INDUCED PRESSOR RESPONSES BY CALCIUM ANTAGONISTS

• 1 After ganglionic blockade and bilateral vagotomy, vasopressor responses induced by activation of postsynaptic α₁- and α₂-adrenoreceptors were elicited in the intact circulatory system of rabbits.
• 2 The hypertensive effects of the selective stimulating agents methoxamine (α₁-agonist) and B-HT 920 (α₂-agonist) were effectively antagonized by the adrenoreceptor antagonists prazosin and yohimbine, respectively. These findings confirm the existence of two types of postsynaptic α-adrenoreceptors (α₁-and α₂-type) in vascular smooth muscle of rabbits.
• 3 The calcium antagonistic drug nifedipine did not affect the maximal increase in diastolic pressure brought about by methoxamine, whereas it strongly inhibited the hypertensive effects of B-HT 920.
• 4 It is concluded that this confirmation of the selective inhibition of postjunctional α₂-adrenoreceptor-mediated vasopressor responses by a calcium antagonistic drug, such as nifedipine, indicates that this activity constitutes a general phenomenon. This finding supports the hypothesis that an influx of extracellular calcium is necessary for the vasoconstriction mediated by postsynaptic α₂-adrenoreceptors.

     

OBSERVATIONS ON THE EFFECT OF MASSIVE DOSES OF IRON GIVEN INTRAVENOUSLY TO PATIENTS WITH HYPOCHROMIC ANEMIA

Massive doses of iron (from 0.608 to 1.32 Gm. as colloidal terric hydroxide orcolloidal ferric oxide) were given intravenously in single infusions to 8 differentpatients with hypochromic microcytic anemia. One patient was given a secondinjection after an interval of four months, so that nine administrations were made.The following observations were made:

1. The reticulocyte response was higher in each instance than would be expectedin oral therapy. In 3 additional patients in whom injection had to be discontinuedafter 0.070, 0.180, and 0.123 Gm. of elemental iron had respectively been given, thereticulocyte rises were higher than were the average responses reported by Heath¹⁸after optimal oral therapy. This at least suggests that "optimal" oral therapy doesnot provide a maximal stimulus to outpouring of reticulocytes from the bone marrow. Comparable doses of iron given to 3 control subjects with normal hemoglobinlevels did not cause a reticulocytosis.

2. The average rate of hemoglobin regeneration per 100 cc. of blood per day was0.224 Gm.; the lowest value was 0.16 Gm. and the highest 0.27 Gm. These figureswere calculated for the rise that occurred from the day of iron administration to thetime at which the rate of hemoglobin increase was obviously becoming slower.Since correction was not made for blood loss in 3 of the patients during the periodof regeneration, the figures for the rate of hemoglobin formation are lower thanthey otherwise would have been. Even so they are distinctly greater than thoseusually obtained following oral therapy (table 2), but no greater than is found in anoccasional patient given iron by mouth. The data suggest that the fastest rate ofhemoglobin regeneration that can be stimulated by iron in subjects with hypochromic anemia approximates 0.3 Gm. per 100 cc. per day.

3. Calculations indicated that from 71.8 to 99.7 per cent of the injected iron wasapparently used for the synthesis of hemoglobin. These figures are likewise lowerthan they would have been if several of the patients had not lost blood during therecovery period. The observation of other workers that parenterally administerediron is almost completely retained by the body and converted into hemoglobin wastherefore confirmed.

4. Toxic reactions to the injected iron are described in detail. They were severein all but two instances, and in 3 patients were so alarming that injection of ironhad to be discontinued. There can be no doubt that the reactions to iron parenterally administered in large doses are great enough to contra-indicate use of thismeasure as a therapeutic procedure.

     

A study of the antigenicity of Rickettsia helvetica proteins using two‐dimensional gel electrophoresis

Rickettsia helvetica is an obligate intracellular Gram‐negative microorganism found in Ixodes ricinus ticks. When R. helvetica was first discovered in 1979, little was known about its physiology and it fell into oblivion until it recently was suspected of being pathogenic to humans. However, all efforts to isolate R. helvetica from patients have been unsuccessful, although serological responses against R. helvetica can be demonstrated. The aim of our study was to investigate the protein profile of R. helvetica and study the antigenicity of its proteins using two‐dimensional (2D) immunoblot in order to characterize the immunological response against R. helvetica infection. Our results show that in addition to the known PS120 and OmpB antigenic R. helvetica proteins, three other antigens exist: a 60 kDa GroEL protein, a 10 kDa GroES protein and a hitherto unknown 35 kDa hypothetical protein that has similarities with ORF‐RC0799 of Rickettsia conorii. Furthermore, the lipopolysaccharide showed strong antigenicity. In this study, we present the first proteome map and the first 2D immunoblot profile of R. helvetica and finally we present the 35 kDa R. helvetica as an additional antigen to the previously known rickettsial antigens.     

X‐linked hereditary motor sensory neuropathy (type 1) presenting with a stroke‐like episode

X‐linked hereditary motor sensory neuropathy type 1 (CMTX 1) is caused by mutation in the GJB1 gene that codes for the connexin 32 protein. Central nervous system involvement with or without white matter changes on magnetic resonance imaging (MRI) has rarely been reported in this condition. We report the case of a 7‐year‐old, previously well male who presented with a stroke‐like episode that manifested as left hemiparesis and dysphasia. An initial brain MRI showed white matter signal changes affecting the corpus callosum and periventricular areas with a posterior predominance. Our patient made a complete clinical recovery in 36 hours. Clinical examination at this stage showed no evidence of a peripheral neuropathy. A repeat brain MRI 6 weeks later showed almost complete resolution of the changes seen initially. Subsequent investigations showed a Val177Ala mutation in the GJB1 gene. This mutation has so far not been described in the Caucasian population and has been only described once before. Electrophysiological studies showed a mixed demyelinating and axonal sensorimotor neuropathy in keeping with CMTX 1. Five months after the initial presentation our patient developed clinical evidence of a peripheral neuropathy in the form of absent ankle reflexes, weak dorsiflexors, and evertors of both feet.     

Effectiveness of community participation in vector-borne disease control

Vector-borne diseases continue to represent a major public healththreat in Latin America. Although vertical programmes that reliedon large teams of workers were successful in stopping or significantlyreducing transmission of malaria, yellow fever and Chagas' diseasein many countries earlier in this century, they have recentlybeen less effective due to a variety of reasons, including thehigh cost of labour and insecticides. Although participatoryapproaches to the control of disease vectors appear to havemany advantages, they have been difficult to implement due toa number of historical, social and cultural factors which arepresent in Latin America. Taking Aedes aegypti control programmesas an example, it is shown that for community participationto work, there must be willingness to define the form participationwill take in consultation with the community, and commitmenton the part of local governments to addressing local concerns,such as difficulties in obtaining good quality drinking water.