By R. Copper. Cooper Union for the Advancement of Science and Art.
Reﬂexes are loss and may occur in ‘transient ischaemic attacks’ generic alavert 10 mg free shipping, which may there is loss of sensation over the perianal region partially recover buy alavert 10 mg otc. Management Clinical features Identiﬁcation and treatment aimed at the underlying Patients may present with clumsiness, weakness, loss of cause. In as many as 20% of cases, the cord compression sensation, loss of bowel or bladder control which may is the initial presentation of an underlying malignancy. Back pain may precede the gent neurosurgical decompression is required to max- presentation with cord compression for many months imise return of function. On Prognosis is related to the degree of damage and speed examination there may be a spastic paraparesis or tetra- of decompression. Bladder control that has been lost for paresis with weakness, increased reﬂexes and upgoing more than 24 hours is usually not regained. Chapter 7: Disorders of the spinal cord 331 Syringomyelia and syringobulbia Management Decompression of the foramen magnum, aspiration of Deﬁnition the syrinx, sometimes with placement of a shunt may Asyrinx is a ﬂuid ﬁlled slit like cavity developing in the halt progression. Aetiology The cavity or syrinx is in continuity with the central Aetiology canal of the spinal cord. It is associated with a history Causes include syphilis, viral and mycoplasma infec- of birth injury, bony abnormalities at the foramen mag- tions, multiple sclerosis, systemic lupus erythematosus num, spina biﬁda, Arnold–Chiari malformation (herni- and post-radiation therapy. Some cases have been re- ation of the cerebellar tonsils and medulla through the ported post-vaccination. Pathophysiology Pathophysiology The expanding cavity may destroy spinothalamic neu- Inﬂammation may be due to vasculitis, or the preceding rones in the cervical cord, anterior horn cells and lateral infection. Clinical features Mixedupper and motor neurone signs, sometimes in an odd distribution, it is usually bilateral, but may affect Clinical features one side more than the other. The patient trinsic muscles of the hand, with loss of upper limb may complain of a tight band around the chest, which reﬂexes and spastic weakness in the legs. Upper motor neurone changes are loss of pain and temperature sensation signs are found below the lesion. C5 to T1 with preservation torneurone signs are found at the level of the lesion, due of touch. Neuropathic joints, neuropathic ulcers and to involvementofthe anterior horn cells. Other investigations are di- ﬁfth nerve nuclei causes loss of facial sensation, classi- rected at the underlying cause, e. Microscopy Disorders of muscle and Affected muscles show abnormalities of ﬁbre size, with neuromuscular junction ﬁbre necrosis, abundant internal nuclei and replacement by ﬁbrofatty tissue. Muscular dystrophies Complications Myotonic dystrophy Patients show neuroﬁbrillary tangles of Alzheimer’s dis- ease in the brain with ageing. Infants born to mothers Deﬁnition withmyotonicdystrophymayhaveprofoundhypotonia, Inherited disease of adults causing progressive muscle feeding and respiratory difﬁculties, clubfeet and devel- weakness. Sex M = F Prognosis The condition is gradually progressive with a variable Aetiology/pathophysiology prognosis. Each generation has increased numbers of repeats resulting in an earlier onset and more severe dis- Deﬁnition ease. Thegenecodesforaproteinkinase,whichispresent Acquired disorder of the neuromuscular junction in many tissues, the mechanism by which this causes the characterised by muscle fatiguability, ptosis & dys- observed clinical features is unknown. Clinical features Incidence Patients develop ptosis, weakness and thinning of the 4in100,000. The thymus appears to be in- r Nervestimulation shows characteristic decrement in volved in the pathogenesis, with 25% of cases having evoked muscle action potentials following repetitive athymoma and a further 70% have thymic hyperplasia. Management r Myasthenic syndromes can be caused by d- Oral anticholinesterases such as pyridostigmine treat the Penicillamine, lithium and propranolol. Care ference with and later destruction of the acetylcholine should be taken when prescribing other medications as receptor. Thymectomy in older patients ercise increases the degree of muscle weakness, and rest with hyperplasia alone is more controversial, tumours allows recovery of power. This can cause difﬁculty with swal- r Plasmapheresis and intravenous immunoglobulin are lowing and eating – the chin may need support whilst usually reserved for severe acute exacerbations. The respiratory muscles may be affected in Severity ﬂuctuates but most have a protracted course, amyasthenic crisis requiring ventilatory support. Ini- exacerbations are unpredictable but may be brought on tially the reﬂexes are preserved but may be fatiguable, by infections or drugs. Aetiology/pathophysiology Investigations Antibodies directed against the presynaptic voltage- r Edrophonium (anticholinesterase) – Tensilon test – gated calcium channels have been detected. The ocular and smell) although this may be found in elderly patients bulbar muscles are typically spared. Test ability of each nos- gravis, weakness tends to be worst in the morning and tril to detect several common smells. The optic nerve Investigations Anatomy r Nerveconduction studies show an incremental re- The optic nerve carries information from the retina via sponse when a motor nerve is repetitively stimulated, the optic chiasm, the lateral geniculate bodies and optic in direct contrast to the ﬁndings in myasthenia gravis radiation to the occipital lobe where the visual cortex is (where there is a decremental response).
He has published more than 100 research papers and review articles in reputed journals and books buy alavert 10 mg visa. He joined the Uni- versity of Tours as a faculty member in 1982 cheap alavert 10 mg amex, became associate professor in 1987, and a full Professor in 1993 at the faculty of Pharmacy, University of Bor- deaux 2, Bordeaux, France. He is currently group leader of a “study group on biologically active plant substances” at the Institute of Vine and Wine Sciences, which comprises 20 scientists and research students. He has published more than 80 research papers in internationally recognized journals. He is involved in developing courses and research on phytochemistry and biological properties of compounds from vine and wine in France and has traveled widely as a senior professor. Scientists from several countries are working in his laboratory and his research is supported by funds from the Vinegrowers Association, Ministry of Higher Education and Research, and various private enterprises. Sukhadia University Laboratory of Biomolecular Udaipur-313001 Technology, Department of Botany India M. Brisson 37007-Salamanca Department of Biochemistry Spain and Microbiology, Research in Heath corchpu@usal. Ganeshaiah Quebec Department of Genetics and Plant Canada Breeding G1K 7P4 University of Agricultural Sciences louise. Geszprych Department of Forest Biology Department of Vegetable College of Forestry and Medicinal Plants Sirsi 581401 Warsaw Agricultural University India Nowoursynowska 159 02-776 Warsaw Sumita Jha Poland Centre of Advanced Study in Cell and Chromosome Research Seemanti Ghosh Department of Botany Centre of Advanced Study in University of Calcutta Cell and Chromosome Research 35 Ballygunge Circular Road Department of Botany Calcutta 700019 University of Calcutta India 35 Ballygunge Circular Road sjbot@caluniv. Mathur Laboratory of Plant Physiology Laboratory of Biomolecular Faculty of Agricultural Technology, Department of Botany Biotechnology M. Sukhadia University Agricultural University of Athens Udaipur-313001 Iera Odos 75 India 11855 Athens Greece Professor Jean-Michel Mérillon spiroskintzios@usa. Salim Laboratory of Biomolecular College of Pharmacy Technology, Department of Botany The Ohio State University M. Węglarz Ashoka Trust for Research in Department of Vegetable Ecology and the Environment #659 and Medicinal Plants 5th A Main Warsaw Agricultural University Hebbal Nowoursynowska 159 Bangalore 560024 02-776 Warsaw India Poland weglarz@alpha. Plant secondary metabolites can also serve as drug precursors, drug prototypes, and pharmacological probes. Re- cent developments in drug discovery from plants, including information on approved drugs and compounds now in clinical trials, are presented. There are also several plant extracts or “phytomedicines” in clinical trials for the treat- ment of various diseases. Keywords Natural products, Plant-derived drugs, Drug discovery, Drug development, Drug precursors, Drug prototypes, Pharmacological probes, New therapeutic agents, Clinical trials, Accelerated discovery techniques 1. Plants have also been utilized for additional purposes, namely as arrow and dart poisons for hunting, poisons for murder, hallucinogens used for ritualistic purposes, stimulants for endur- ance, and hunger suppression, as well as inebriants and medicines. The plant chemicals used for these latter purposes are largely the secondary metabolites, which are derived biosynthetically from plant primary metabolites (e. These secondary metabolites can be classifed into several groups according to their chemical classes, such alkaloids, terpenoids, and phenolics . Kinghorn Arrow and dart poisons have been used by indigenous people in certain parts of the world with the principal ingredients derived from the genera Aco- nitum (Ranunculaceae), Akocanthera (Apocynaceae), Antiaris (Moraceae), Chondrodendron (Menispermaceae), Strophanthus (Apocynaceae), and Strych- nos (Loganiaceae) . Most compounds responsible for the potency of arrow and dart poisons belong to three plant chemical groups, namely the alkaloids (e. In some cultures, toxic plant extracts were also used for murder and “trials by ordeal,” where a person accused of a crime was given a noxious brew, and it was believed that if innocent, this suspect would survive this ordeal. Certain plants formerly used for arrow poisons, such as several Aconitum species, have also been used as medicines at lower dosages, for their analgesic and anti-in- fammatory properties . In fact, many compounds isolated from poisonous plants were later developed as therapeutic drugs, due to their desirable pharma- cological actions [5, 6]. The use of hallucinogens in the past was usually associated with magic and ritual. However, these hallucinogens have been exploited as recreational drugs and accordingly may lead to habituation problems. Several well-recognized plants that contain hallucinogenic or psychoactive substances (the compound names are given in parentheses) include Banisteriopsis caapi (Spruce ex Griseb. Several of these plants are also used as drugs due to their desired pharmaco- logical activities, and some of the constituents of these plants have been devel- oped into modern medicines, either in the natural form or as lead compounds subjected to optimization by synthetic organic chemistry [5, 6]. The Aztec nobility used to consume bitter beverages containing raw cocoa beans (Theo- broma cacao L. Nowadays, tea, coffee, and cocoa are important commodities and their consumption has spread world- wide. The active components of these stimulants are methylated xanthine de- rivatives, namely caffeine, theophylline, and theobromine, which are the main constituents of coffee, tea, and cocoa, respectively . Chapter 1 Drug Discovery from Plants 3 The most popular inebriants in society today are wine, beer, and liquor made from the fermentation of fruits and cereals. The intoxicating ingredient of these drinks is ethanol, a by-product of bacterial fermentation, rather than secondary plant metabolites.
For this individual buy cheap alavert 10mg, the probability of ileus as the cause of his abdominal symptoms is unlikely order alavert 10 mg line, because he has a history of crampy abdominal pain and find- ings of high-pitched bowel sounds, which are clinical features compatible with mechanical obstruction and not functional obstruction. The radiographic studies will help to distinguish partial obstruction from high grade, complete obstruction. The presence of stool or air in the rectal vault may suggest a partial obstruction, whereas the presence of air and fluid levels in the small intestine, with the absence of stool and air through- out the colon, indicate a high-grade, small-bowel obstruction. Examples include an isolated loop of small bowel caught in a tight hernia defect, a twisting of the bowel on itself causing a volvulus, or a complete large-bowel obstruction in a patient with a competent ileo- cecal valve. It is also useful in the evaluation of patients with previous abdominal malignancy to help determine if the obstruction is related to tumor recurrence. Etiologies include neurogenic dysfunction, medication-related or metabolic problems, bowel wall infiltrative processes such as collagen vascular diseases, or extraluminal infiltra- tive processes such as peritonitis or malignancy. Surgery generally does not improve the above conditions; however, complications related to the above conditions may require operative intervention. The treatment can be operative or nonoperative depending on the cause, severity, and duration of the obstructive process. The administration of con- trast may be associated with worsening of obstruction and aspiration. Adhesions represent the most common cause of small- bowel obstruction whereas colorectal carcinoma is the most common cause of large-bowel obstruction in developed countries. Table 20–1 lists the distribution and clinical features associated with obstructive causes. Pathophysiology With mechanical obstruction, air and fluid accumulate in the bowel lumen. The net result is an increase in the intestinal intraluminal pressure, which inhibits fluid absorption and stimulates the influx of water and electrolytes into the lumen. Eighty percent of air found inside the bowel lumen is swallowed air (see Figure 18–1). Initially following the onset of mechanical obstruction, there is an increase in peristaltic activity. However, as the obstructive process progresses (usually >24 hours), coordinated peristaltic activity diminishes along with the contractile function of obstructed bowel, giving rise to dilated and atonic bowel proximal to the point of obstruction. With this progression, the patient may actually appear to improve clinically with less frequent and less intense crampy abdominal pain. The effects of mechanical obstruction on intestinal blood flow include an initial increase in blood flow. With unrelieved obstruction, blood flow diminishes leading to a breakdown of mucosal barriers and an increased susceptibility to bacterial invasion and ischemia. The presence or absence of these signs and symptoms are dependent on the severity of the obstruction. Pain associated with bowel obstruction is generally severe at the onset and is characterized as intermittent and poorly localized. With the progression of small-bowel obstruction, spastic pain decreases in intensity and frequency. Patients with large-bowel obstruction, pain frequently present with postprandial crampy pain, and some patients with chronic large-bowel obstruction may describe the symptoms as indigestion. Continuous pain may also develop with the progression of marked distension, ischemia, or perforation. In general, patients with proximal obstruction of the small bowel report the most dramatic episodes, whereas patients with distal obstructions may not experience as much emesis. The quality of the material vomited may help indicate the level of obstruction, as obstruction in the distal small bowel may produce feculent vomitus. Contrary to common beliefs, obstruction of the large bowel often is not associ- ated with vomiting, because the presence of a competent ileocecal valve (found in 50%-60% of individuals) frequently contributes to a closed-loop obstruction. Absence of bowel movements and flatus are suggestive of a high-grade or complete obstruction. With the stimulation of peristalsis at the initiation of an obstructive episode, it is not unusual for a patient to describe having bowel move- ments. The presence of a recent bowel movement does not rule out the diagnosis of a bowel obstruction. The classic description of decreased stool caliber is infrequently reported by patients with large-bowel obstruction, and when reported, this finding is not specific for colonic obstruction. On the other hand, diarrhea is frequently reported by patients with progressive large-bowel obstruction. Presumably, with high-grade narrowing of the bowel lumen, passage of the solid and semisolid con- tents are blocked, therefore the stools become more liquid in character. Distension to some degree is generally observed in most patients with intestinal obstruction; however, this finding may be absent in patients with obstruction of the proximal small bowel; therefore, the absence of distension does not eliminate the possibility of intestinal obstruction. Patients with uncomplicated obstruction usually have mild, ill-defined, non- localized abdominal tenderness. The tenderness results from distension of the bowel wall leading to the aggravation of visceral pain. Localized tenderness is a finding that is infrequently encountered in patients with uncomplicated bowel obstruction, and the presence of localized tenderness is suggestive of complications involving an isolated bowel segment.