***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: The present study extends a previous report of lower plasma ACTH levels in women with premenstrual syndrome ( PMS ) compared with asymptomatic controls .  Plasma levels of estradiol and progesterone were measured daily in 10 women with confirmed PMS and 8 asymptomatic women . Daily symptom reports were maintained during the same menstrual cycle . Both estradiol and progesterone levels were consistently , but not significantly , higher throughout the cycle in PMS subjects compared with controls . From the follicular to the early luteal phase , estradiol levels were significantly higher in a previously defined PMS subgroup 2 with more severe symptoms throughout the cycle compared with both the less severe PMS subgroup 1 and controls . Progesterone levels were significantly and positively correlated with PMS symptoms along the entire menstrual cycle , preceding the symptoms by 5 - 7 days . These preliminary results provide support for the hypothesis that the presence of progesterone at early luteal phase levels is required for PMS symptoms to occur OBJECTIVES To explore the possible role of natriuretic peptides and vasopressin in luteal phase fluid retention in premenstrual syndrome ( PMS ) and to determine the effect of progesterone therapy on these hormones . DESIGN Self-controlled prospect i ve study . SETTING University-based medical research centre . PATIENTS Six patients with PMS were studied during the symptomatic luteal and asymptomatic follicular phases . The follicular phase response was used as the control for each subject . INTERVENTIONS An intravenous infusion of 3 % saline solution was administered on an early follicular and a late luteal phase day in 2 menstrual cycles . Progesterone was administered orally during the second luteal phase . OUTCOME MEASURES Osmolality , arginine vasopressin ( AVP ) , atrial natriuretic factor ( ANF ) , and brain natriuretic peptide ( BNP ) levels in plasma , osmolality , sodium , potassium , cyclic adenosine monophosphate ( cAMP ) and cyclic guanosine 5'-phosphate ( cGMP ) concentrations in urine , and thirst sensation . RESULTS Mean basal plasma ANF and osmolality levels and the threshold for AVP release and thirst were lower , and mean urinary cyclic nucleotide levels and AVP sensitivity ( amount of AVP secreted per unit rise in plasma osmolality ) were higher , in the luteal phase than in the follicular phase . With saline loading , there was an increase in plasma osmolality , AVP and ANF and in urinary sodium and cyclic nucleotide levels . Plasma ANF and osmolality levels remained lower in the luteal phase compared with the follicular phase , but AVP levels at the end of the saline infusion were higher in the luteal phase than in the follicular phase . Progesterone therapy caused an increase in plasma ANF and osmolality levels and the AVP threshold and a decrease in AVP levels and sensitivity and urinary cyclic nucleotide levels . BNP levels did not change with phase or treatment . The differences in AVP threshold with phase and treatment were statistically significant ( p < 0.001 ) . There was a significant phase effect for plasma ANF ( p = 0.02 ) and a significant or near-significant interaction effect of phase and treatment for plasma ANF ( p = 0.06 ) and urinary cAMP ( p = 0.047 ) and cGMP ( p = 0.066 ) . The effect of phase and treatment was not significant for the other measurements . CONCLUSIONS Luteal phase fluid retention may be due to a relative deficiency of ANF and a lower threshold for AVP release . The symptomatic improvement produced by progesterone treatment may be due to its stimulation of ANF and inhibition of AVP release or synthesis Plasma levels of prolactin , FSH , LH , progesterone and 17–β‐oestradiol in twenty women with premenstrual tension were compared with those in twenty controls . The former group was studied also during treatment with bromocriptine .  The mean prolactin level in the PMT group was lower in the follicular phase than in the luteal phase ( P < 0.±01 ) , but there was no difference between the PMT and control group in the luteal phase . No differences were found between the controls and the PMT group in FSH , LH , 17–β‐oestradiol and progesterone levels in the luteal phase . Bromocriptine  suppressed prolactin concentrations ( P < 0.±01 ) , but had no effect on the FSH , LH , 17‐B‐oestradiol or progesterone levels Previous studies have indicated that the addition of progestins during sequential  hormonal replacement therapy ( HRT ) causes negative mood and physical symptoms . History of premenstrual syndrome , type of progestin , and dose of progestin have thus far been shown to influence the progestin-induced adverse mood symptoms during HRT . The aim of this study was to compare adverse mood effects of two different doses of estradiol , in combination with a progestin , during postmenopausal HRT . Twenty-eight perimenopausal women were included in this r and omized , double-blind , crossover study comparing 2- or 3-mg continuous estradiol , with an addition of 10 mg medroxyprogesterone acetate on d 17 - 28 during each treatment cycle . The main outcome measures were mood and physical symptoms kept on a daily rating scale . Together with the progestin , the higher dose of estrogen caused significantly more negative mood symptoms than the lower dose . Tension , irritability , and depressed mood were all significantly augmented during the progestin phase of cycles with 3 mg estradiol ( P < 0.001 ) . Physical symptoms also increased during the progestin phase of 3-mg estradiol cycles ( P < 0.001 ) , whereas positive mood symptoms were less affected . The only positive mood that changed with estrogen dose was friendliness , which decreased during the progestin phase of high estradiol cycles compared with cycles with lower estradiol ( P < 0.05 ) . Our conclusion is that an increase of the estrogen dose accentuates negative mood and physical symptoms during the progestin phase of sequential hormonal therapy OBJECTIVE This study characterizes the responses to placebo medication of patients with premenstrual syndrome ( PMS ) who were r and omly assigned in controlled treatment trials . Possible predictors of placebo response were also examined . METHOD Subjects from two r and omized controlled trials were pooled . The 101 subjects met defined criteria for severe PMS , remained eligible after 1 month of single-blind placebo lead-in treatment , and were r and omly assigned to 3 months of double-blind placebo treatment . Improvement in the current study was defined as a decrease of at least 50 % in premenstrual symptom score from the pretreatment baseline . RESULTS At endpoint , 20 ( 20 % ) of the placebo-treated subjects showed sustained improvement , 18 of these in at least 3 of the 4 months of placebo medication . Another 42 % of subjects partially improved , and 39 % were clearly unimproved throughout the study period . CONCLUSIONS Some patients with severe PMS experience significant and sustained improvement with placebo medication , but the majority report only partial or no improvement . Patients who sustain improvement for at least 2 consecutive months are likely to remain improved , indicating the importance of nondrug factors in clinical care OBJECTIVE To explore the pulsatile-release characteristics of LH and P  in women with premenstrual syndrome ( PMS ) compared with age-matched phase-matched controls . DESIGN Prospect i ve , repeated measures , two-group study . SETTING Human volunteers in an academic research environment . PARTICIPANTS Six women with rigorously defined prospect ively determined PMS ; six age-matched phase-matched controls . MAIN OUTCOME MEASURES Frequency , amplitude , concentration , and coincident pulsatile release characteristics of LH and P  at three symptom-related points of the luteal phase . RESULTS No significant between-group differences in frequency , amplitude , or concentration were found . In pooled data , significant coincident pulsing between LH and P was demonstrated . The length of time between LH and P pulses systematic ally increased across the luteal phase , a finding not previously reported . In the PMS group only , significant coincident pulsing occurred at an unexpected zero time lag on the symptom-onset sampling day . CONCLUSION A progressively increasing coupling interval may reflect the gradual decline of the corpus luteum . Presence of a zero time lag between LH and P at symptom onset in women with PMS may indicate an aberrance in corpus luteum response to LH stimulation Some studies suggest that patients suffering from premenstrual syndrome ( PMS ) may be affected by an endogenous opioid dysfunction . Since opioids are the main modulators of the pulsatile LH secretion , we evaluated plasma LH pulsatility in 13 patients with PMS ( aged 33.1 yr ) and in six asymptomatic control volunteers ( aged 31.5 yr ) , in the late luteal phase ( -7 , -5 days before their next menses ) . The patients were prospect ively evaluated for two menstrual cycles with the Menstrual Distress Question naire ; the main symptoms which worsened during the premenstrual period were mood swings and water retention . The pulsatility of plasma LH secretion was studied by collecting blood sample s every 10 min for 12 hr , starting at 0800h . The presence of LH pulses was estimated using the program DETECT on the raw data . This program also allows the computation of the instantaneous secretory rate ( ISR ) . Ovulation was ascertained in all the controls and in nine PMS patients by means of urinary LH assay and luteal progesterone ( P ) determination . The remaining four patients did not ovulate . Both the ovulatory and the anovulatory PMS patients had an increased number of LH pulses/12 hr ( 10.3 + /- 2.4 and 11.5 + /- 4.4 , mean + /- SD , respectively ) in comparison with the controls ( 7.0 + /- 1.3 pulses , p less than 0.01 ) , together with a reduced amplitude and duration . Similar findings were obtained with the ISR computation . Plasma P levels were similar in both the ovulatory patients and controls . The increased frequency and reduced amplitude of LH pulses in the PMS patients most likely reflect a dysfunction of hypothalamic Gn-RH release , possibly linked to a reduction of opioid inhibition This essay traces the history of premenstrual syndrome ( PMS ) in French , British , and American medical literature from 1950 to 2004 . Aetiological theories , treatments and diagnostic criteria have varied over time and place , reflecting local conditions and changing notions of objectivity and evidence . During the 1970s research ers in each nation utilised different research strategies to overcome variation and contradictory results characteristic of PMS research . Since the 1980s , attempts have been made to st and ardise research internationally through prospect i ve daily rating question naires that diagnose and measure PMS . Amidst controversy , a psychiatric reformulation of the syndrome was included in the Diagnostic and Statistical Manual of Mental Disorders ( DSM ) . While the diagnostic criteria for this psychiatric category , now called premenstrual dysphoric disorder ( PMDD ) , are widely accepted for research purpose s , efforts to transfer them to medical practice have been less successful . PMDD remains a contested disease construct A review of measures of menstrual cycle symptoms is provided . This will enable research ers and clinicians to make the appropriate choice of method for their study requirements . In recent years , these measures have taken the form of retrospective question naires ( rating severity of symptoms from memory  ) and prospect i ve diaries ( daily checklists of symptoms )  . Many of these draw on aspects of the well-known retrospective question naires , the Menstrual Distress Question naire and Premenstrual Assessment Form , in their development and validation . Each measure will be briefly described , followed by comments on its development , psychometric properties and finally an evaluation of its strengths and weaknesses . It concludes with an examination of the implication s arising from the review , and some recommendations that menstrual cycle research ers and clinicians may wish to consider , as they decide upon the most appropriate measure for their needs The present study evaluates the  luteal progesterone ( P ) and LH secretions  in 14 patients affected by premenstrual syndrome ( PMS ) and in 14 asymptomatic controls through the evaluation of their episodic release . PMS was prospect ively confirmed in two consecutive menstrual cycles using Moos ' Menstrual Distress Question naire . A pulsatility study was performed during the luteal phase . Blood sample s were drawn every 10 min for 12 h , beginning at 0800 h. Statistically significant pulses were detected using the Detect program , and the degree of concordance of LH and P pulses was estimated . Similar mean 12-h P levels were found in controls ( mean + /- SD , 13.9 + /- 9.3 nmol/L ) and patients ( 14.2 + /- 10.1 ) .  LH levels were also similar in the two groups . Patients showed a higher P pulse frequency ( 13.4 + /- 1.8 vs. 11.4 + /- 2.3 ; P < 0.02 ) and a reduced amplitude of secretory episodes ( 126.5 + /- 61.6 % vs. 187.1 + /- 126.7 % ; P < 0.03 ) than controls . Similarly , PMS patients showed pulsatile LH release of increased frequency and reduced amplitude than controls . A significant degree of concordance between LH and P pulses was observed in both groups , with a time lag of 0 - 10 
    Output:
    
The trials did not show that progesterone is an effective treatment for PMS nor that it is not .
Neither trial distinguished a subgroup of women who benefited , nor examined cl aim ed success with high doses