By J. Hjalte. Hartwick College.

The precise mechanism that triggers orgasm has been a topic of debate for many years but purchase chloromycetin 250 mg fast delivery, as of yet purchase chloromycetin 250 mg with mastercard, no denitive mechanisms have been identied. Only very recently have investigators examined the brain areas activated during orgasm in women (21). Some of these areas may be more involved in the perception of sexual stimuli than with the actual triggering of orgasm. Further studies that compare brain imaging during sexual arousal without orgasm with brain imaging at orgasm are needed to determine whether there are any areas of the brain specically involved in generating orgasm. Masters and Johnson (2) claimed that all orgasms in women were physiologically identical regardless of the source of stimulation. However, they did not have the instrumentation to obtain detailed muscular recordings for possible differences between clitoral- and vaginal- induced orgasms. There is now some limited physiological laboratory evidence to suggest that different patterns of uterine (smooth muscle) and striated pelvic muscular activity may occur with vaginal anterior wall stimulation as opposed to clitoral stimulation (15). Several other physiological differences between male and female orgasms have been proposed. First, unlike men, women can have repeated (multiple) orgasms separated by very short intervals, and women can have extended orgasms that last for long periods of time (2). Secondly, men have a divided rhythmic pattern of muscular contractions that has not been noted in women (9). Thirdly, in men, once orgasm is initiated its further expression is automatic even if sexual stimulation is stopped. In contrast, if stimulation is stopped in the middle of either clitoral-induced or vaginal-induced orgasm, orgasm is halted in women (26). In terms of gender differences in the psychological experience of orgasm, written descriptions of orgasms by men and women with any obvious gender clues removed could not be differentiated by sex, when read by other males and females (27). It is generally accepted that female orgasms are not essential for reproduction, and any benet that they may have for female biology is, as yet, unclear. Early theorists believed that orgasm via intercourse activated ovulation and closed off the womb to air, thus facilitating conception (28). When it was later shown that the human female was a spontaneous ovulator at mid-cycle, and that this was unconnected to coitus, the discourse re-focused on the role of uterine suction created by orgasmic contractions in moving ejaculated spermatozoa through the cervix into the uterus and then fallopian tubes. However, there is now good evidence that the fastest transport of spermatozoa into the human uterus is actually in the sexually unstimulated condition (29). An essential feature of sexual arousal of the female genitalia is to create the expansion of the vagina (vaginal tenting) and elevation of the uterocervix from the posterior vaginal wall. By dissipating arousal and initiating the resolution of the tenting, orgasm may allow the earlier entry of the spermatozoa into the cervical canal and their subsequent rapid transport to the fallopian tubes. It has been suggested that women may use orgasm, initiated either from coitus or masturbation, as a way to manipulate the ejaculate in the vagina (30,31). This highly contentious concept is based on the amount of owback (semen/uid) lost from the vagina. The claim is that the amount of owback con- taining spermatozoa varies with the precise timing of the womans orgasm in relation to the time of deposition of the ejaculate into the vagina. Low sperm retention is thought to be associated with female orgasms that occur less than 1 min before vaginal deposition while maximum retention is thought to occur with orgasms occurring shortly after deposition. If orgasm occurs earlier than 1 min before the ejaculate, deposition sperm retention is the same as when there is no orgasm. According to Baker and Bellis (31) the effect of orgasm on sperm retention lasts only for the period of 1 min before semen deposition and up to 45 min later. An additional function of womens orgasm, which may play a role in the reproductive process, is that if the woman attains orgasm during coitus, the associated contractions of the vagina can facilitate male ejaculation. If prolactin in plasma is able to enter into the vaginal, cervical or uterine uids, it may inu- ence the entry of calcium into the sperm and this action could play a role in the activation of spermatozoa in the female tract (32). There have been a number of other explanations offered for why women have orgasms. To the extent that orgasm is an intensely pleasurable sensation, it serves as a reward for the accep- tance of the danger of coitus with its possibility of pregnancy and of possible death in childbirth. Orgasm serves as a means for resolving pelvic vasoconges- tion and vaginal tenting, and for inducing lassitude to keep the female horizontal and thereby reducing seminal owback. Lastly, by its activation of muscular contractions and the concomitant increased blood ow, orgasms maintain the functionality of the genital tract (33). There is variability, however, in that some antidepressants have been associated with anorgasmia less frequently than others. Women treated with uoxetine, paroxetine, and sertraline for anxiety disorders reported delays in reaching orgasm and decreased quality of orgasm at 1 and 2 month follow-ups (39). However, the impairments in the uoxetine group decreased by the end of the third month. In contrast to these ndings of impaired orgasm with uoxetine, one multicenter open-label study of uoxetine reported an improvement in womens orgasmic ability associated with the amelioration of depression (40). Antipsychotic medications have also been reported to inhibit orgasm in women (41).

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Atrial brillation is less common than omy) is indicated in patients who are symptomatic or in mitral stenosis generic chloromycetin 500 mg overnight delivery. Chest X-ray: the left atrium and ventricle are en- indicated if the valve morphology is not suitable for larged buy chloromycetin 250mg online, the former sometimes being enormous. Echocardiography helps to distinguish between the anticoagulation or concomitant moderate to severe various causes and to assess left ventricular regurgitation. Assessment of the dominance of the lesions in com- Mitral regurgitation bined mitral stenosis/mitral regurgitation: mitral stenosis is more likely to be the dominant lesion if Aetiology the pulse volume is small (in the absence of failure). Indications nary congestion and this is followed by right heart for anticoagulation are atrial brillation, systemic failure. A left parasternal heave may be present and is Tricuspidregurgitationmaybecausedbydilatationof causedbysystolicexpansionoftheleftatriumrather thetricuspidvalveringinrightventricularfailurefrom than by right ventricular hypertrophy. Auscultation: there is an apical pansystolic murmur associatedwithdisease ofmitraland/oraorticvalves), radiating to the left axilla. Mitral valve prolapse produces a late systolic click open tricuspid valve) andmurmur. It occurs in two clinical murmur, loudest in inspiration, heard at the lower situations. Cardiovascular disease 101 Pulmonary stenosis previous infection and there is little or no risk to the fetus. If the titre is not raised, a repeat sample is Pulmonary stenosis is usually congenital but may measured 34 weeks later (or if symptoms appear in follow maternal rubella. Rarely, it is associated with themother)andifthetitrehasrisensignicantly,thisis Noonan syndrome (Turners phenotype affecting evidenceofrecentinfection. Theearlierthatthisoccurs males and females with normal chromosome num- in the pregnancy, the greater the risk to the fetus. Patients may show peripheral cyanosis, a low- Down syndrome (usually volumepulseandalargeawaveinthejugularvenous 21-trisomy) pulse wave. There is a systolic thrill and mur- This is associated with septal defects, particularly mur in the pulmonary area (second left intercostal ventricular. Hearing loss, renal anomalies It usually occurs in the left atrium and presents with and hypothyroidism are recognised associations. It is best diagnosed by echocardiogra- Marfan syndrome phy where the tumour produces characteristic echoes (arachnodactyly) as it moves between the mitral valve leaets in ven- tricular diastole and in the atrium in systole. It is fatal This is an autosomal dominant connective tissue unless removed surgically. Rarely it is a manifestation disorder which affects the aortic media, eyes and of the autosomal dominant Carney Complex. Itischaracterisedbydisproportionatelengthofthe long bones, which results in span exceeding height and long ngers and toes. There is frequently a high arched palate, Congenital heart disease may present as an isolated pectus excavatum, scoliosis, little subcutaneous fat cardiacabnormalityoraspartofasystemicsyndrome. The aortic media is weak with a tendency to dilatation of the ascending aorta and aortic valve ring, resulting in aortic valve Maternal rubella regurgitation and dissection of the aorta. Mitral Maternal rubella infection is dangerous in the rst 3 regurgitation may develop. The cardiac lesions Working classication are in three groups: An asterisk denotes the most frequent. Fertile women given Regurgitation vaccine must not become pregnant in the immediate future. If raised, this is evidence of pid regurgitation, Ebsteins anomaly 102 Cardiovascular disease Shunts Chest X-ray. Compared with other congenital heart de- through the defect results in pulmonary hyperten- fects, there is a high (and late) incidence of atrial sion with pressure above systemic level, a reversed brillation (20%) and an extremely low incidence of shunt develops. Tricuspid regurgitation (from right ventricular because it tends to involve the atrioventricular enlargement). Management Surgical repair has been largely replaced by percuta- Symptoms neous closure. In simple lesions there are usually no symptoms, although dyspnoea occurs in 10% of cases. Patent ductus arteriosus This represents 15% of all cases of congenital heart Signs disease. Flow through the defect does not itself produce a murmur, but increased right heart output Symptoms gives a pulmonary ow murmur and large shunts may Usually there are none. A left parasternal lift of right ventricular The pulse may be collapsing (water hammer) and the hypertrophy may be present. There is a continuous (machinery) murmur with systolic accentuation, maximal in the second left intercostal space and Assessment posteriorly. Ostium primum: usually, there is left axis deviation Assessment with evidence of right ventricular hypertrophy. Echocardiography shows a dilated left atrium and monary circulation left ventricle. Ifthisisunsuccessful, This accounts for 10% of cases of congenital heart surgical ligation (15 years) is required or possibly an disease and 50% of cyanotic congenital heart disease.

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It is often discussed whether resistant Salmonella develops primarily as a result of antibiotic use in agriculture or in human medicine buy chloromycetin 500mg. Although both uses always play a part chloromycetin 250 mg line, it is more probable that antibiotic resistance in Salmonella causing infection mainly reflects resistance developed in the animal reservoirs. Human infection has been associated with the consumption of chicken, beef, pork sausages and meat paste, and to lesser extent with direct contact with farm animals. The pigs suspected of carrying this resistant strain had not been fed any fluoroquinolones, but the compounds may previously have been used at the farms. Wild animals or equipment may have spread the bacteria environmentally, and concomitantly with globalization of trade such outbreaks could become more common (Swint, 1999). Integrons are a group of apparently mobile elements that can contain one or more antimicrobial resistance genes. Integrons represent an important and efficient mechanism by which many bacteria, including S. The fact that integrons are widespread among Gram-negative bacteria suggests that these genetic elements have evolved into a highly adaptable and very efficient mechanism by which cells can acquire and express antimicrobial resistance genes (Ribot et al. None reported other underlying illnesses, and none reported taking any antibiotics before specimens were collected. Molecular evidence supports the suggestion that some of the antimicrobial resistance determinants found in S. Florfenicol was evaluated as a therapeutic agent in fish in Asia in the early 1980s (Kim and Aoki, 1996; Yasunaga and Tsukahara, 1988). Kim, Yoshida and Aoki (1993) reported the emergence of florfenicol-resistant strains of P. Enteritidis phage type 4 as the principal agent of human salmonellosis in England and Wales. Some isolates possess additional plasmid-mediated resistance to trimethoprim and low-level resistance to ciprofloxacin because of point mutations in the gyrA gene. The potential exists for the horizontal transfer of genetic elements such as antibiotic resistance gene cassettes between Salmonella serotypes and phage types. Typhimurium isolates received at the Central Public Health Laboratory, London, in 2000. The resistance observed reached a prevalence of 50 percent in isolates from calves in a defined area of the country. Subsequently the prevalence of these resistant strains has diminished, but data associating this change in prevalence with changes in fluoroquinolone usage in animals are unavailable. There is uncertainty about the relative contribution to the emergence and dissemination of quinolone-resistant Salmonella of direct selective pressure versus the spread of resistant strains in the presence or absence of quinolone use. Variation is reported in the rate of emergence of animal strains with reduced susceptibility to fluoroquinolones in different countries after the introduction of fluoroquinolones for use in food animals. In contrast to patients with uncomplicated gastroenteritis, effective antimicrobial agents are essential for the treatment of patients with bacteraemia, meningitis or other extraintestinal Salmonella infections. The selection of antimicrobial agents for the treatment of invasive infections has become increasingly restricted due to increasing antimicrobial resistance among Salmonella isolates. In the past, ampicillin, chloramphenicol and trimethoprim- sulfamethoxazole have been the treatment of choice for Salmonella infections (McDonald et al. Should Salmonella develop antimicrobial resistance to these antimicrobial agents, suitable alternative antimicrobial agents are not currently available and serious adverse human health consequences can be expected. Ampicillin use declined from 60 percent in 1985 to 5 percent in 1995, whereas the proportion of isolates resistant to ampicillin steadily increased (Angulo et al. Trimethoprim-sulfamethoxazole use, in contrast, remained constant, whereas trimethoprim-sulfamethoxazole resistance increased slightly. Importantly, the proportion of patients with salmonellosis treated with ciprofloxacin or extended-spectrum cephalosporins markedly increased without an emergence of resistance to either of these antimicrobial agents among human Salmonella isolates. These data suggest there is little correlation between the antimicrobial agents used in persons with Salmonella infections and development of antimicrobial resistance among human Salmonella isolates. Risk assessment 17 If human antimicrobial use is not associated with the increasing antimicrobial resistance seen among Salmonella isolates, what is causing the increasing prevalence of antimicrobial-resistance observed among Salmonella isolates? Possible sources for an increased number of an unusual strain of Salmonella among human isolates may be indicated by the emergence of the same unusual strain among isolates from animals, foods, and other sources. Such investigations often reveal that the source of the increase has been traced to foods of animal origin. For example, beginning in 1969, there was a marked increase in human isolates of Salmonella Agona detected in the United States of America and several other countries (Angulo et al. Salmonella Agona had not been isolated in the United States of America before 1969, but by 1972 it was the eighth most common serotype isolated from humans in the United States of America (Clark, Kaufmann and Gangrosa, 1973). Field investigations and surveillance data determined Peruvian fishmeal fed to chickens was the source of the infections.

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