Transfer rates from freestanding birth centers. A comparison with the National Birth Center Study

This article reviews retrospective data derived from Sharp The BirthPlace. San Diego for 1993-94 and from the University of California. Irvine, Birthing Center for 1994 and compares these findings to data obtained from the National Birth Center Study (NBCS). The focus of this article is on intrapartum transfer rates from the two freestanding birth centers as a critical clinical indicator. Cause-specific transfer rates were calculated for eight clinical conditions. Data suggest that cause-specific intrapartum transfer rates are influenced by factors such as risk profile of the client population, distance to the referral center and mechanisms of transfer, definitions and diagnostic criteria used, and clinical practice guidelines. Reports from the literature, such as NBCS data, might serve as points of reference, but are likely not appropriate baseline indicators (benchmarks of "best practice") for clinical events, against which individual performance can be measured; rather, these benchmarks should be individually defined, based on characteristics unique to each birth center.

L-arginine is unlikely to exert neuroendocrine effects in humans via the generation of nitric oxide

There is now considerable evidence that nitric oxide is an important neuroregulatory agent, but there has been very little investigation of its possible role in neuroendocrine mechanisms in humans. We have investigated the effects of two nitric oxide precursors, L-arginine and molsidomine, under basal conditions on the pituitary hormones growth hormone (GH), prolactin, luteinizing hormone, follicle-stimulating hormone, thyrotrophin, adrenocorticotrophin (ACTH) and vasopressin, and also on serum cortisol; we have also studied the effect of L-arginine on circulating prolactin, ACTH and cortisol in normal human subjects under hypoglycaemic stress. L-Arginine stimulated both GH and prolactin release under basal conditions but had no effect on the other hormones studied, while the nitric oxide donor molsidomine showed no effect on any hormone studied. L-Arginine potentiated the hypoglycaemia-stimulated release of ACTH but did not influence the rise in GH. The current studies suggest that the effects of L-arginine on the stimulation of GH and prolactin release are unlikely to be mediated via the generation of nitric oxide.

The acute cardiovascular actions of intravenous thyrotrophin releasing hormone (TRH) in man are mediated by non-catecholaminergic mechanisms

1. Intravenous bolus doses of thyrotrophin releasing hormone (TRH, 50-1000 micrograms) caused statistically significant, non-dose dependent and transient rises in blood pressure, heart rate and plasma catecholamines in healthy young males. 2. Mean peak incremental rises in systolic blood pressure (mean +/- s.e. mean) following 50, 200 and 500 micrograms TRH were 14.3 +/- 2.9 mmHg, 15.7 +/- 3.2 mmHg and 17.1 +/- 3.9 mmHg respectively (all P < 0.05 vs placebo). Mean incremental rises in heart rate for the three doses of TRH were 8.2 +/- 2.2 beats min-1, 7.1 +/- 1.8 beats min-1, and 10.7 +/- 2.9 beats min-1 respectively (all P < 0.05 vs placebo). 3. Following the 50 micrograms and 1000 micrograms doses of TRH, plasma noradrenaline and adrenaline rose significantly (P < 0.05) between 4 and 8 min. Mean +/- s.e. mean incremental plasma noradrenaline rise following 50, 200 and 100 micrograms TRH were 0.4 +/- 0.13 nmol 1(-1), 0.37 +/- 0.21 nmol 1(-1) and 0.41 +/- 0.18 nmol 1(-1) respectively. Mean +/- s.e. mean incremental rise in adrenaline for the 50, 200 and 1000 micrograms dose were 0.13 +/- 0.04 nmol 1(-), 0.08 +/- 0.03 nmol 1(-1), and 0.11 +/- 0.05 nmol 1(-1) respectively. 4. Following administration of the ganglion blocking drug pentolinium (5 mg) the incremental systolic blood pressure and heart rate rises following 500 micrograms TRH alone 16.6 +/- 2.8 mmHg and 10.4 + 3.1 beats min-1 respectively. 5. The rises in plasma noradrenaline and adrenaline following TRH were attenuated by prior ganglion blockade. 6. alpha-Adrenoceptor blockade with thymoxamine (0.3 mg kg-1 bolus + 0.3 mg kg-1 h-1 infusion), singly and combined with intravenous propranolol (10 mg i.v. over 10 min), did not alter the pressor or tachycardic effects of 500 micrograms TRH. 7. In conclusion, although plasma noradrenaline rises following i.v. TRH, suggesting activation of the sympathetic nervous system, this effect is not responsible for the pressor response to TRH, which appears to be due to either a direct vasoconstrictive effect on the peripheral resistance vessels or a direct inotropic/chronotropic effect on the heart.

Diagnosis of growth hormone deficiency in adults

The potential effects of growth hormone (GH) deficiency in adults and the importance of GH secretion in adult life have only been recognized and documented recently. It has been suggested that GH-deficient adults may have premature mortality, abnormalities in body composition and bone density with impaired physical performance and psychological well-being, which are sometimes improved by GH replacement. It is essential, therefore, to establish reliable standards to define GH deficiency in adults. Patients with possible GH deficiency often have primary pituitary or hypothalamic disorders or have undergone surgery or radiotherapy, and thus show evidence of a failure of one of the other pituitary hormones. Several biochemical approaches have been studied to define GH deficiency in the adult and no universal consensus has yet been reached. The most widely established criterion is the peak serum GH concentration achieved during a provocative test, usually the insulin tolerance test (ITT), or following other pharmacological stimuli (e.g. glucagon, arginine, clonidine or GH-releasing factor) but, alternatively, a more physiological stimulus (such as sleep, fasting or exercise) has been used. Spontaneous circulating levels of hormones of the GH axis [24-hour integrated GH concentration, serum insulin-like growth factor I (IGF-I) or IGF-binding protein-3] have been used in the diagnosis of childhood GH deficiency. They have been tested in adults as well but seem to have a more limited role. There are several factors complicating the evaluation of these results. Basal and stimulated GH and IGF-I levels decline with age and with obesity, levels tend to be higher in females and are dependent on nutritional and physical status. The ITT potentially has some risk attached, e.g. in the presence of ischaemic heart disease, but it has proved to be safe in general when used in specialized departments. Other tests are less reliable; releasing hormone tests only assess the readily releasable stores within the pituitary and not the physiological secretory status. The 'cut-off' point for the definition of subnormal responses ideally needs to be set for each provocative test, for each age group, for each degree of obesity and for both sexes. There is considerable variability in GH assays among different laboratories, which makes it difficult to compare hormone levels. The reproducibility of provocative tests can also be variable. An advantage of the hypoglycaemia and glucagon tests is that they allow simultaneous assessment of the adrenocorticotropic hormone reserve.

Levels of lead in blood and bone of women giving birth in a Boston hospital

Blood lead levels declined among Americans aged 1-74 y between the years 1976 and 1991 (National Health and Examination Survey [NHANES III]). In 1990, umbilical cord blood lead levels were surveyed among 223 women who gave birth in a Boston hospital obstetrical service. In a survey conducted 10 y earlier, women had a mean umbilical cord blood lead level of 6.56 micrograms/dl (standard deviation = 3.19). In another subgroup of 41 women who were 1-4 wk postpartum, bone lead levels were surveyed with a K-x-ray fluorescence instrument and by analysis of venous blood lead levels. In 1990, umbilical cord blood lead levels were very low (i.e., mean and median of 1.19 [standard deviation = 1.32] and 1.0 micrograms/dl, respectively. In the subgroup of postpartum women, lead levels in cortical bone (i.e., tibia) and trabecular bone (i.e., patella) were also low (i.e., tibia mean and median of 4.5 [standard deviation = 4.0] and 4 micrograms/g bone mineral, respectively); patella mean and median of 5.8 [standard deviation = 4.5] and 5 micrograms/g, respectively). Maternal age was the only factor associated (i.e., borderline [p=.076]) with bone lead. Umbilical cord blood lead levels among women served by this Boston hospital from 1980 to 1990 declined dramatically, thus paralleling the National Health and Examination Survey. Bone lead levels were also low, but lead remains a reproductive hazard to women in select high-risk groups.

Assessment of cure after transsphenoidal surgery for Cushing's disease

The best long-term results of transsphenoidal surgery appear to be in those patients who have unmeasurable serum cortisol levels in the immediate post-operative period. This appears to be due to isolated ACTH deficiency in the remaining normal pituitary gland. In our experience, however, long-term clinical remission may be possible with measurable serum cortisol levels post-operatively. The cortisol response to ACTH or CRF appears to provide no greater discrimination than basal measurements and is possibly less helpful than dexamethasone suppression. The prolonged clinical remission that we have seen in some patients with early measurable but low cortisol levels, together with the possible operative morbidity and partial success of repeat surgery, suggests careful assessment before a recommendation is made of an immediate second operation in these patients. The possibility of cyclical secretion of cortisol must be considered both pre and post-operatively. Finally, as experience with transsphenoidal surgery is still relatively short, all these patients need continuing endocrine follow-up in centres with adequate experience of the condition. For the individual patient we recommend that decisions regarding further therapy are based on 0800-0900 h serum cortisol levels, an index of cortisol production (serum cortisol day profiles or 24 hour urinary free cortisol), and the response to low dose dexamethasone suppression in the early post-operative period.

A single sleeping midnight cortisol has 100% sensitivity for the diagnosis of Cushing's syndrome

OBJECTIVE

The diagnosis of Cushing's syndrome remains a major challenge in clinical endocrinology. Various screening tests are commonly used to support a biochemical diagnosis in the context of clinical suspicion. The aim of this study was to compare the sensitivity in the diagnosis of Cushing's syndrome of a single in-patient sleeping midnight cortisol to a standard 48-hour in-patient low-dose dexamethasone suppression test (LDDST) during the same admission.

DESIGN

A retrospective analysis was performed on 150 patients investigated in our department between the years 1970 and 1994 with a confirmed diagnosis of Cushing's syndrome.

PATIENTS

One hundred and fifty patients with a diagnosis of Cushing's syndrome were analysed: 110 with Cushing's disease; 12 with tumours with ectopic ACTH secretion; 8 with ACTH dependent Cushing's syndrome of so far undetermined origin; 17 with cortisol secreting adrenal tumours; 3 with adrenocortical nodular hyperplasia. Twenty normal volunteers and nine patients with non-endocrine conditions were also investigated as controls.

MEASUREMENTS

Plasma cortisol was measured by radioimmunoassay (RIA) in the 122 patients presenting after 1980, and by fluorimetry prior to this date.

RESULTS

In all the control subjects the sleeping midnight cortisol was < 50 nmol/l, below the lowest standard of the routine in-house RIA. In every patient with Cushing's syndrome the sleeping midnight cortisol was detectable with a value greater than 50 nmol/l, with a range of 70-2000 nmol/l. In contrast, in three cases, all of whom had proven Cushing's disease on histology, there was uncharacteristic complete suppression of plasma cortisol to < 50 nmol/l following the LDDST.

CONCLUSION

In this series of 150 cases, a single in-patient sleeping midnight cortisol above 50 nmol/l had a 100% sensitivity for the diagnosis of Cushing's syndrome, clearly different from normal subjects. In contrast, the low-dose dexamethasone suppression test had a sensitivity of 98% even when the drug was administered as an in-patient. We recommend that a low-dose dexamethasone suppression test should not be used alone for confirmation of Cushing's syndrome since it may miss 2% of cases.

MR and positron emission tomography with fludeoxyglucose F 18 in gliomatosis cerebri

A 16-year-old girl presented with a unilateral third nerve palsy and predominant gray matter involvement on MR and positron emission tomography with fludeoxyglucose F 18. These findings were manifestations of gliomatosis cerebri. The antemortem diagnosis was made by partial temporal lobectomy.

Outcome of patients with neurotrauma: the effect of a regionalized trauma system

A system of regionalized trauma care was introduced to Sydney in early 1992. This study was carried out to assess the effect of regionalization on the outcome of patients suffering major head injury within the central Sydney area. A prospective before and after study extending over 3 years and centred on the time of designation of Royal Prince Alfred Hospital (RPAH) as a trauma centre, was the methodology used. The study group consisted of all patients admitted with head injury (Glasgow Coma Score < 9; admission systolic blood pressure > 90 mmHg; Injury Severity Score > 15) to RPAH from the central Sydney area. Outcome criteria include survival rates, transfer numbers, and time to definitive neurosurgical care. Fifty patients were entered during the first 18 months of the study, and 38 during the second 18 months. Fifteen in the first group required evacuation of intracranial mass lesions, as did nine in the second group. The overall mortality fell from 42 to 26% (P = 0.13). During the study period there were 77 primary retrievals and 20 required evacuation of mass lesions. The median time from injury to commencement of operation in these patients was 2 h 13 min (range 1 h 3 min-5 h 35 min). There were 11 transfers, four requiring craniotomy. The median time from injury to surgery was 7 h 24 min (range 3 h 2 min-10 h 25 min; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cushing's syndrome. Therapy directed at the adrenal glands

Establishing the exact etiologic diagnosis of Cushing's syndrome is fundamental to the management of the disease. It allows for specific therapy, such as pituitary microsurgery. In cases where the adrenal gland is the cause, treatment can be either surgical or medical. This article explores both types of treatment and their respective results.

Fatal pulmonary embolism by tumor during resection of a choroid plexus papilloma: case report

A unique case of pulmonary embolization of a tumor in a patient undergoing resection of a choroid plexus papilloma is presented. The possible mechanisms by which this occurs are discussed, as are the implications of the possible seeding of the tumor to distal sites by microembolization.

Criteria for medical as opposed to surgical treatment of prolactinomas

The treatments for both true and pseudoprolactinomas are reviewed. True prolactinomas, usually characterized by pituitary lesions and circulating levels of prolactin in excess of 2 U/l (100 micrograms/l), are best treated with a dopamine agonist such as bromocriptine. Administration of 50 mg of a repeatable bromocriptine depot preparation (Parlodel-LAR, Sandoz, Basel, Switzerland), results in a prompt reduction of circulating prolactin levels to within normal limits over 48 h in a patient with macroadenoma. Bromocriptine treatment results in a reduction of circulating prolactin in 80% of patients and tumour shrinkage in about two-thirds. Patients with macroadenomas treated successfully with dopamine agonists should be given pituitary radiotherapy to provide long-term ablation of the prolactin-secreting cells and facilitate a gradual cessation of drug. Tumours which are not responsive to dopamine agonists should undergo trans-sphenoidal surgery. Pseudoprolactinomas usually associated with circulating prolactin levels < 2 U/l (100 micrograms/l) are caused by a peripituitary tumour which obstructs the flow of dopamine into the pituitary. Treatment with dopamine agonists reduces prolactin levels but does not result in tumour shrinkage and so the treatment of choice is trans-sphenoidal surgery. Surgery is also indicated in patients with intolerance to dopamine agonists.

Nitric oxide modulates the release of corticotropin-releasing hormone from the rat hypothalamus in vitro

There is now considerable evidence that nitric oxide (NO) is an important neuroregulatory agent, but there has been very little investigation of the possible role of NO in neuroendocrine mechanisms. We have previously shown that acute rat hypothalamic explants can be used to study the regulation of hypothalamic neuropeptide release, and we have now utilised this experimental approach to investigate the putative involvement of NO in the control of the principal corticotropin-releasing hormone, CRH. We studied the direct effects of the NO precursor L-arginine (L-ARG), as well as the NO donors molsidomine and sodium nitroprusside, on both the basal and stimulated release of CRH; the stimuli used were non-specific depolarisation with potassium chloride (KCl) and the specific cytokine, interleukin-1 beta (IL-1 beta; 100 U/ml). L-ARG was tested in each experimental condition with and without contemporaneous addition of its competitive antagonist NG-monomethyl-L-arginine (L-NMMA). IL-1 beta-induced CRH release was also investigated in the presence of D-arginine (D-ARG), which is not active as a precursor to NO, and ferrous hemoglobin (Hb), a substance which is a potent inactivator of NO. None of the NO precursors (L-ARG, molsidomine, sodium nitroprusside) or antagonists (L-NMMA or Hb) was able to affect basal CRH release. However, L-ARG 10 and 100 microM were found to significantly inhibit the release of CRH induced by 40 mM KCl; CRH fell to 45% of its stimulated level at the higher dose of L-ARG. This effect was attenuated in the presence of L-NMMA at a ten-fold higher dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic osteomyelitis in patients with Gaucher's disease

Bone involvement in patients with Gaucher's disease is common, and some of its clinical manifestations may resemble acute osteomyelitis. In addition, many studies have emphasized the high risk of secondary infection when surgical procedures are performed at the site of the involved bone. Nevertheless, these infections have never been well documented in the literature. Presentation of a patient with Gaucher's disease and osteomyelitis due to Prevotella (Bacteroides) melaninogenica provided us the opportunity to review 10 other similar case reports documented in the literature since 1966. This review suggests that acute hematogenic osteomyelitis is an uncommon complication of Gaucher's disease, but it is of interest that in most cases it is due to unusual organisms, particularly anaerobes.

Controversies in the management of brainstem cavernous angioma: report of two cases

Two cases of cavernous angioma involving the medulla oblongata are presented. Both cases underwent surgical excision with excellent outcome. The use of surgery via craniectomy is contrasted with stereotactic radiosurgery in light of the known natural history of the lesions. As a result, it is suggested that surgical excision provides immediate protection from the risks of recurrent haemorrhage, establishes a tissue diagnosis, allows complete removal at the primary intervention, avoids complications of radiation-induced damage and is performed more easily in these vascular anomalies due to the presence of a capsule with surrounding gliotic tissue. Additionally, it is implied that the natural history of lesions in this region is still unclear. For these reasons, it is suggested that surgical excision should be the primary therapeutic intervention for cavernous angiomata that involve the brainstem.

Interleukin-1 beta and interleukin-6 specifically increase the release of prostaglandin E2 from rat hypothalamic explants in vitro

It has previously been shown that the cytokines interleukin-1 beta and interleukin-6 (IL-1 beta and IL-6) stimulate directly the release of corticotrophin-releasing-hormone-41 from the rat hypothalamus in vitro, while IL-1 beta can also stimulate the release of somatostatin. These effects can be antagonized by drugs which block prostaglandin (PG) synthesis. PGs are also involved in the control of hypothalamic neuropeptides by other neurotransmitters. In the present study, we have characterized the production of PGs from the rat hypothalamus in vitro, and investigated the effects of IL-1 beta and IL-6, as well as the neurotransmitters norepinephrine, acetylcholine and 5-hydroxytryptamine, on the acute release of PGs, using a well-validated acute hypothalamic incubation system. The rate of release of PGs [PGE2, PGF2 alpha, 6-keto-PGF1 alpha (6KPGF1 alpha) and thromboxane B2 (TXB2) in the medium was found to stabilize after 60 min of preincubation and thereafter remain constant, with TXB2 being the predominant species. Twenty-minute incubation in the presence of human recombinant IL-1 beta or IL-6, in the dose range 1-100 U/ml, had no effect on the release of PGF2 alpha, 6KPGF1 alpha or TXB2; however, the release of PGE2 was significantly increased by both IL-1 beta and IL-6. The effect of IL-1 beta was antagonized by both indomethacin and dexamethasone. None of the other neurotransmitters tested had any effect on the release of any of the PGs.(ABSTRACT TRUNCATED AT 250 WORDS)

Pseudotumor syndrome in treated arachnoid cysts

We report three patients with arachnoid cysts treated by cyst-peritoneal shunting in whom intracranial hypertension occurred during episodes of shunt malfunction. In one case this was associated with re-expansion of the arachnoid cyst, whilst in the other two cases this did not occur. The similarities between these two cases and patients with pseudotumor cerebri suggest a common pathogenic mechanism--specifically, a disturbance of the cerebrospinal fluid circulation.

Spinal cord compression in prostate cancer. A 10-year experience

Of 478 patients treated at a single institution for prostate cancer, 29 developed spinal cord or cauda equina compression. In 5 patients, spinal cord compression was the first evidence of malignancy. Clinical features were predominantly pain, weakness, sensory and sphincter disturbance. The median duration of symptoms was 2 weeks, although the diagnosis was made rapidly at presentation. Clinical diagnosis correlated well with myelographic findings. Only 1 patient suffered neurological deterioration as a consequence of myelography. The functional outcome was dependent on the ability to walk prior to treatment. The median survival in those who were bedridden following treatment was 6 weeks (range 3.5-13) and 21 weeks (range 7-110+) in those who were ambulant following therapy.

Management of prolactinomas

The management of prolactinomas requires a complex interaction of medical, surgical and radiotherapeutic intervention. With the judicious use of all these modalities, patients can usually be managed with great success and, perhaps more importantly, their presenting complaints (gonadal dysfunction and infertility) are usually completely corrected.