Hemp is an annual herb plant which is used for production fibre for such as rope, sail and clothing as well as the seed crushed for oil, food and feed. Due to the outer portion of the hemp stem contains strong and long bast, fibre provides a strength and high quality textile, while inner of the stem so called hurd also used for paper and building material. After Thai royal project interested in developing industrial hemp as an economic crop to support the hill tribes, the quality seed are needed to propagate and disperse for the farmer. In addition, the cultivation of hemp is being permitted in Thailand especially in the north, but under strict control and monitoring by office of the narcotics control board of Thai. Hemp is determined a dioecious crop and seed production is required a wider space from plant to plant than producing as fibre. In addition as an annual crop, cultivated seed are usually sown in early March and late of May, and harvested in the end of November under preferable natural temperature 14 – 27 ºC. Therefore, they are attractive to produce exceed seed supply and then stored for one or several years for cultivation. Storage of seed is an important process of plant production to avoid unfavourable environmental conditions and the acceleration of the deteriorations, which is started after harvest. Storage conditions play an important role to maintain high seed quality, which directly related to environmental conditions. However, the sensitivity of seed to high temperature is depended on the water content that the higher moisture content, the looser viability. Seed deterioration is associated with the genotype, seed history and their physiological and chemical compositions. As in hemp, seed is determined as an orthodox seed that can be dried to low moisture content and stored at low temperature for several years. Nonetheless, the seed contain 20 – 25% protein, 20 – 30% carbohydrates, 10 – 15% insoluble fibre and especially 25 -35% oil which was considered to be the major contributors to seed deterioration as previous demonstrations of soybean , peanut and sunflower. For hemp seed, it was suggested that seed should be dried until the moisture content lower than 12%. Consequently,vertical farming for further storage, either high or low relative humidity affected the moisture equilibrium of seed due to hygroscopic property. Then, the type of container was important for protecting moisture immigration.
As in closely fibre species such as kenaf , seed stored at 8% mc remains viable for up to 5.5 years when stored at 8 ºC and stored above 10 ºC and 12% mc showed significant decrease in seed viability. In parallel, Meints and Smith, also found that germination of kenaf under ideal conditions remained high in seed stored up to 4 years at 10 ºC and did not show appreciable differences in field emergence or performance through the growing season. Determination of hemp seed qualities which were derived from segregation of the local land race would assist the Royal project and further seed supplier in reliable on fibre hemp production. The objectives of this study were to determine the impact of storage conditions and hemp seed quality losses during year storage. These experiments were conducted to compare storage condition affecting different hemp seed cultivars by observing the physiological of seed qualities. The moisture contents at which these changes are observed among cultivars, and continuously involve in the change of stored seed quality. The seed cv. RPF2 contained higher moisture content than the others and also showing lower initial germination illustrated significantly decreased with storage time when packed in both seal aluminium foil and plastic bag at ambient temperature. McDonald stated that the effect of high temperatures on seeds quality is highly dependent on their water content and the loss of viability was more rapid when the seed contain high moisture. However, the quality of seed packed in both materials was not different during 5 month, but after that aluminium foil had an adverse effect on reduction of seed viability and vigour than plastic bag during 5 – 8 month. This suggested that high moisture content seeds might be closely oppressed to dry air and then water remove to the surface because of hygroscopic of which higher moisture content was observed in seed packed in aluminium foil. The change of moisture content was not different when seed stored in aluminium foil at 15, 4 and –4 ºC, while the seed germination and vigour was also remained. The result revealed that aluminium foil has better water and oxygen proved properties than plastic bag made from polypropylene which the exchange were 0.0914/m2 /hr and 0.2472/m2 /hr for oxygen; 65 g-water/m2/hr and 1378 g-water/m2/hr for water, respectively. This suggested that initial moisture content and germination are the main factor for providing seed longevity. Hemp seed containing high moisture content stored at room temperature maintained the germination and vigour only up to 5 months of storage, after that the conditions and aging was deleterious to seed viability. Seed deterioration is associated with various biochemicals, metabolic and physiological alteration including loss of membrane integrity and cell compartmentalization, decreasing in ATP production and impairment of RNA and protein biosynthesis.
Moreover, lipid peroxidation and free radicals were considered to be the major contributors to seed deterioration , especially, at high temperature, it was mainly related to membrane damage and alteration of energy metabolisms as demonstrated in sunflower. In the other hand, seed germination and vigour of low seed moisture content as cv. RPF3 contained in aluminium foil at room temperature remained viable. This previous study mentioned that the dehydration of seed could prevent thermal denaturation. Marijuana use dates back to 2727 BC to Chinese Emperor Shen Nung. After spreading through the Greek and Roman empires and into the Islamic empire of North Africa and the Middle East, it was brought to the Western hemisphere by the Spanish. Originally lauded for its utility as fiber, it was not until its migration into North America that it began to be used in a similar fashion as it is today. Used in the form of hemp, it was seen throughout society as rope, clothing and even paper. While marijuana has been used by Americans recreationally for years, it is a subject that is becoming more commonplace in our modern society. According to the National Institutes of Health, marijuana use in 2015e2016 rose from 4.1% to 9.5% of the U.S. adult population. With more states eliminating the legal ramifications of its use and a growing debate about its federal legality, this is a subject that routinely makes local and national headlines. With a diverse array of commercial products becoming available from chocolate squares to oral sprays, marijuana is also no longer restricted to a rolled cigarette. The medical community has also joined the debate. The most obvious correlation between medicine and marijuana is medicinal marijuana. Marijuana’s effects have been well documented, allowing the push for its use as medicine within multiple specialities. Proponents of its use point to its effects on the endocannabinoid system. Studies show that through its impact on different pathways it may be used as an analgesic, immunosuppressant, muscle relaxant, anti-inflammatory agent, appetite modulator, antidepressant, antiemetic, bronchodilator, neuroleptic, antineoplastic and antiallergen. Medical marijuana also differs in chemical composition, containing a higher tetrahydrocannabinol concentration and less cannabinol than the recreational version. This is even before taking into consideration the various extraneous agents that may be found within the available recreational drug.
There is however, very little, if any research evaluating marijuana’s use in surgery. This paucity of literature presents a problem. While many surgeons may ask about recreation drug use including marijuana, many other drugs have established evidence based outcomes that allow variation in surgical planning as needed. However, when it comes to marijuana, surgeons are left to determine what to do with this information on their own.Despite the multiple studies on the physiologic effects of marijuana use, clinical studies, if any, are not cited in the medical literature. This study reviews the literature available on marijuana’s effects and discusses potential complications that may result within the surgical setting. With a reported estimation of 10%e20% of patients between the ages of 18 and 25 years regularly using marijuana, this review seeks to become an initial step for further exploration of the subject and to reveal why there is a need for more in-depth research.Due to limited research and reviews on this subject, information was utilized from articles on surgery in various fields, such as orthopedic, dental and bariatric with anesthesia considerations and general topics related to marijuana also examined. The following information was gathered: marijuana’s prevalence in the United States, marijuana’s effects on the cardiovascular system and pulmonary system, potential coagulopathies, marijuana’s effects in relation to anesthesiology, evidence based screening methods for recreational drug use, potential surgical complications that may result from marijuana use,flood tray and recommendations on marijuana use and surgery.When marijuana is smoked, THC and other cannabinoids are absorbed rapidly through the lungs with effects peaking in 15 minutes. These effects can persist for up to a dose-dependent 4 hours in the acute setting. When ingested orally however, onset of effects is slower but has a longer duration of action , due to continued absorption in the gut. This is despite a lower bioavailability due to first-pass metabolism by the liver which results in a blood concentration 25% of what is obtained if smoked. The cognitive/psychomotor effects can be present for up to 24 hours regardless of administration route. Cannabinoids are highly lipid soluble. This leads to a slow release into the bloodstream with a single dose not fully eliminated for up to 30 days. The cardiovascular effects of marijuana use range from benign to worrisome based on the timeline of use and dosage.
In a series single blind study comparing the effects of high and low doses of THC in healthy young men, tachycardia was induced beginning within the time of inhalation, and persisting at least 90 minutes, with the maximum heart rate reached at an average of 30 minutes. The study also found a significant elevation in systolic and diastolic blood pressures as well as the presence of premature ventricular contractions in subjects who received the higher doses. These experiments showed a correlation between the dose and the tachycardic and cardiovascular changes. In addition, Malit et al.’s study on the effects of intravenous THC found the majority of patients to exceed the 100 beats per minute mark but also experience intermittent spikes in heart rate with a possible etiology of psychological distress. Beaconsfield et al. postulated a mechanism of beta adrenergic stimulation for the tachycardia as he was able to block the tachycardia with the use of propranolol. Pharmacology lays credence to this. At lower or moderate doses, marijuana increases sympathetic activity reducing parasympathetics and producing an elevation in heart rate, cardiac output and blood pressure. However, the opposite is true as the dosage increases. At high doses, the parasympathetic system takes over, leading to bradycardia and hypotension with animal studies postulating that the sympathetic inhibition occurs due to the bioactive constituent of cannabis’s effects on the CB1 receptors. In addition to sinus tachycardia, marijuana use has been linked to multiple electrocardiogram changes in various case reports. Daccarrett et al. found Brugadalike changes in a 19 year old male with a known history of cannabis use and no anatomical/functional abnormalities. A case was also reported in which cannabis use was linked to the development of atrial flutter and atrial fibrillation, while other studies have reported the presence of sinus bradycardia and AV block.Aronow et al., found that while comparing marijuana to placebo, cannabis causes an increase in carboxyhemoglobin, a resultant increase in myocardial oxygen demand, decrease in oxygen supply as well as an induction of platelet aggregation. One case report showed a 21 year old male who presented with a ST elevation myocardial infarction due to plaque rupture as a complication of marijuana use. In Mittleman et al.’s analysis of over 3,800 cases of myocardial infarction, 124 patients reported use within the last year of which 37 reported use within 24 hours, with 9 reporting use within an hour of the event. The study found a statistically significant 4.8 fold increase in myocardial infarction within the first hour of marijuana use. In fact, as THC content of marijuana increases, there are a growing number of clinical studies demonstrating the association between cannabis use and adverse cardiovascular events. One such study followed 1913 adults prospectively and demonstrated that in patients with prior myocardial infarction, marijuana use up to once per week increased risk of death 2.5 fold while more frequent use yielded a fourfold risk of dying.