The first 100 thrombolysis cases in a novel Scottish mesh telestroke system

Stroke thrombolysis has been a major driver for change within stroke services. However, until recently its widespread application has been limited to tertiary centres. Transfer to tertiary care can lead to significant delays in thrombolysis. We developed a novel mesh telestroke network, which allows stroke specialists to make videoconference-based thrombolysis decisions either from one of three stroke units or from home. We report data on the first 100 patients treated using this model and retrospectively review the first 100 strokes thrombolysed with tissue plasminogen activator across three stroke units. Prospectively collected data were extracted from the Stroke Audit In Lanarkshire database. Case notes were retrieved for clarification when necessary. Outcome measures were timings from symptom onset to infusion, post-thrombolysis symptomatic intracerebral haemorrhage and death. Fifty-one percent of cases were assessed by telestroke link. Median symptom onset to thrombolysis was 160 min (IQR 125–190). There were two symptomatic intracerebral haemorrhages, both in patients assessed face-to-face. Overall mortality was 14%. Our experience of tissue plasminogen activator is comparable to UK data extracted from SITS-MOST in overall timings and complication rates. This model of telemedicine could be replicated to provide safe thrombolysis to areas with challenging infrastructure, geography or insufficient stroke specialist cover.

Bioreactance is not reliable for estimating cardiac output and the effects of passive leg raising in critically ill patients

BACKGROUND

Bioreactance estimates cardiac output in a non-invasive way. We evaluated the ability of a bioreactance device (NICOM®) to estimate cardiac index (CI) and to track relative changes induced by volume expansion.

METHODS

In 48 critically ill patients, we measured CI estimated by the NICOM® device (CINicom) and by transpulmonary thermodilution (CItd, PiCCO2™ device) before and after a 500 ml saline infusion. Before volume expansion, we performed a passive leg raising (PLR) test and measured the changes it induced in CINicom and in pulse contour analysis-derived CI.

RESULTS

Considering the values recorded before PLR and before and after volume expansion (n=144), the bias (lower and upper limits of agreement) between CItd and CINicom was 0.9 (-2.2 to 4.1) litre min(-1) m(-2). The percentage error was 82%. There was no significant correlation between the changes in CItd and CINicom induced by volume expansion (P=0.24). An increase in CI estimated by pulse contour analysis >9% during the PLR test predicted fluid responsiveness with a sensitivity of 84% (95% confidence interval 60-97%) and a specificity of 97% (95% confidence interval 82-100%). The area under the receiver operating characteristic curve constructed to test the ability of the PLR-induced changes in CINicom in predicting fluid responsiveness did not differ significantly from 0.5 (P=0.77).

CONCLUSIONS

The NICOM® device cannot accurately estimate the cardiac output in critically ill patients. Moreover, it could not predict fluid responsiveness through the PLR test.

A comparative toxicogenomic investigation of oil sand water and processed water in rainbow trout hepatocytes

The purpose of this study was to compare the expression of gene transcripts involved in toxic stress in rainbow trout hepatocytes exposed to oil sand water (OSW), lixiviate (OSLW), and processed water (OSPW). We pose the hypothesis that the changes in gene expression responses in cells exposed to a simulated oil sand extraction procedure (OSPW) differ from the gene expression responses of OSLW and OS. Rainbow trout hepatocytes were exposed to increasing concentrations of OSW, OSLW, and OSPW for 48 h at 15 °C. Cell viability was assessed by measuring membrane permeability, total RNA levels, and gene expression using an array of 16 genes involved in xenobiotic biotransformation (GST, CYP1A1, CYP3A4, MDR), metal homeostasis and oxidative stress (MT, SOD, and CAT), estrogenicity (VTG, ERβ), DNA repair (LIG, APEX, UNG, and OGG), cell growth (GADD45 and PCNA), and glycolysis (GAPDH). The results showed that the toxicogenomic properties of OSPW differed from those of OSLW and OSW. Gene transcripts that were influenced by OSW and OSLW, and strongly expressed in OSPW, were MT, CAT, GST (induction), CYP1A1, VTG, UNG/OGG, and PCNA. These genes are therefore considered not entirely specific to OSPW but to water in contact with OS. We also found gene transcripts that responded only with OSPW: SOD, GST (inhibition), MDR (inhibition), CYP3A4, GAPDH, GADD45, and APEX. Of these gene transcripts, the ones strongly associated with toxicity (loss of cell viability and RNA levels) were CYP3A4, GST, and GAPDH. Genes involved in DNA repair were also strongly related to the loss of cell viability but responded to both OSLW and OSPW. The observed changes in cell toxicity and gene expression therefore support the hypothesis that OSPW has a distinct toxic fingerprint from OSLW and OSW.

Deep digital flexor tendon injury within the hoof capsule; does lesion type or location predict prognosis?

The type and location of deep digital flexor tendon (DDFT) lesions may be important in predicting outcome. The objectives of this study were to determine the frequency of different types of DDFT lesions within the hoof capsule and to determine whether lesion type predicts return to athletic activity. Lesions of the DDFT were divided into: core lesions, dorsal border lesions and parasagittal splits. Lesion location was documented, and follow-up information was obtained by telephone survey at least 18 months after diagnosis. Of 168 horses with primary DDFT injury, 54 horses had dorsal border lesions, 59 had parasagittal splits and 55 had core lesions. Twenty-five per cent of all horses returned to previous levels of athletic activity within 18 months of MRI evaluation. Horses with complete splits or core lesions of the DDFT were significantly less likely to return to some level of athletic activity than horses with dorsal border lesions P<0.001. Dorsal border lesions of the DDFT appear to have a better prognosis than core lesions or parasagittal splits. This study provides additional information that may help clinicians predict the prognosis for different types of DDFT injury.

Differential changes in gene expression in rainbow trout hepatocytes exposed to extracts of oil sands process-affected water and the Athabasca River

The oil sands region of northern Alberta represents the world's largest reserves of bitumen, and the accelerated pace of industrial extraction activity has raised concern about the possible impacts on the Athabasca River and its tributaries. An ecotoxicogenomic study was undertaken on Oncorhynchus mykiss trout hepatocytes exposed to extracts of water samples near the oil sand development area, as well as to oil sands process-affected water (OSPW) extracts using the quantitative reverse transcriptase polymerase chain reaction technique. The expression of the following genes (mRNA) was monitored to track changes in xenobiotic biotransformation (CYP1A1, CYP3A4, glutathione S-transferase, multi-drug resistance transporter), estrogenicity (estrogen receptor and vitellogenin), oxidative stress (superoxide dismutase and metallothionein) and DNA repair activity (DNA ligase). The extent of DNA-aromatic hydrocarbon adducts was also determined in cells by immuno-staining. A comparative analysis of gene expression between the river/lake and OSPW samples revealed that CYP3A4, metallothioneins, DNA ligase and GST genes, were specifically expressed by OSPW. Cells exposed to OSPW, commercial naphthenic acids, and benzo(a)pyrene showed increased polyaromatic hydrocarbon DNA-adducts, as determined by cell immunofluorescence analysis. Other genes were induced by all types of water samples, although the induction potential was stronger in OSPW most of the time (e.g., VTG gene was expressed nearly 15-fold by surface waters from the lake and river samples but increased to a maximum of 31-fold in OSPW). A multivariate discriminant function analysis revealed that the lake and river water samples were well discriminated from the OSPW. The CYP3A4 gene was the most highly expressed gene in cells exposed to OSPW and responded less to the lake or river water in the Athabasca River area. This study identified a suite of gene targets that responded specifically to OSPW extracts, which could serve as toxicogenomic fingerprints of OSPW contamination.

Management and treatment of hepatitis B virus in patients with HIV infection: A practical guide for health care professionals

The management and treatment of HIV and hepatitis B virus (HBV)-coinfected patients present specific challenges for clinicians. The morbidity and mortality related to these concomitant infections are growing concerns, while the use of antiviral drugs effective against both viruses complicates therapeutic decision making. The present document provides guidelines for physicians regarding care and treatment of patients coinfected with HIV and HBV. Primary prevention of HBV in HIV-positive patients is achieved through appropriate vaccination schedules. Follow-up before treatment of HBV may include liver biopsy, screening for hepatocellular carcinoma and testing for esophageal varicies in cases of cirrhosis. In HBV-infected patients requiring treatment, recommendations regarding initiation, duration and choice of first-line drugs are made. Finally, in the case of resistance, appropriate alternative therapies are necessary.

Impacts of pollution in feral Mya arenaria populations: the effects of clam bed distance from the shore

This study examined the relationships between population characteristics and the expression of physiological biomarkers of stress in an intertidal clam population under pollution at sites differing in thermal history and coastline distance. The clam population metrics were age distribution, growth, condition factor, distance of the clam beds from the shore, and gonad development. Physiological biomarkers comprised biomarkers of defence such as superoxide dismutase, labile IIb metals in tissues, redox status of metallothioneins and glutathione S-transferase, of tissue damage such as lipid peroxidation and DNA strand breaks, of reproduction as determined by vitellogenin-like proteins and gonadosomatic index and immunocompetence such as phagocytosis and hemocyte viability. Age-related pigments were also examined to compare the physiological age of the clams with their chronological age. The results showed that all the above biomarkers were significantly affected at one of the two polluted sites at least. Distance from the shore was significantly correlated with most (81%) of the biomarkers examined. Clams collected at one polluted site were physiologically older than clams from the corresponding reference site. Canonical and adaptive regression (artificial neural networks) analyses found that the biomarkers measured in this study were able to predict the ecologically relevant endpoints. Biomarkers implicated in defense mechanisms, tissue damage and age-related pigments were most closely related to the clam population characteristics. Sensitivity analysis of the learning algorithm found that the following physiological and biochemical markers were the most predictive, in decreasing order, of clam population characteristics: glutathione S-transferase, phagocytosis, age pigments, lipid peroxidation in the gills, labile IIb metals and total MT levels. These biomarkers were affected by the distance of the clam beds from the shore, site quality (pollution) and reproduction activity.

Switch from enfuvirtide to raltegravir in virologically suppressed HIV-1 infected patients: effects on level of residual viremia and quality of life

BACKGROUND

Raltegravir is a potential treatment option for virologically suppressed HIV-1 infected patients on enfuvirtide with injection site reactions.

OBJECTIVES

To characterize safety and efficacy of an enfuvirtide to raltegravir switch including changes in T-cells, quality of life, and residual viremia.

STUDY DESIGN

In patients with viral load <50 copies/mL and injection site reactions, enfuvirtide was switched to raltegravir without additional changes to the antiretroviral regimen. Virologic failure was defined as a viral load >1000 copies/mL or two consecutive viral load measurements between 50 and 1000 copies/mL (low-level viremia). Over the 24 week study, we compared changes in T-cells, injection site reactions, quality of life, and residual viremia, as measured through the single-copy assay which can detect plasma virus down to a single copy, using paired t-tests.

RESULTS

Fourteen patients with a median CD4+ T-cell count of 420 cells/microL were enrolled. After the switch, two patients experienced virologic failure due to confirmed low-level viremia. However, both patients subsequently were re-suppressed, one without any changes to his regimen. There was no change in CD4+ T-cell count. Injection site reactions resolved. However, there was little reported change in quality of life. The baseline median level of residual viremia was 6 copies/mL and did not change after the switch to raltegravir.

CONCLUSIONS

A switch to raltegravir in virologically suppressed patients on enfuvirtide is effective in maintaining immunologic and virologic control at 24 weeks but did not result in a change in residual viremia.

Relationships between intertidal clam population and health status of the soft-shell clam Mya arenaria in the St. Lawrence Estuary and Saguenay Fjord (Québec, Canada)

The purpose of this study was to examine the impacts of anthropogenic activity on the health status of intertidal clam populations of the Saguenay Fjord and the St. Lawrence Estuary (Québec, Canada). Clams were collected during low tide at sites subject to direct contamination and at sites far from human activity. Clams were analyzed for tributyltin and dibutyltin total levels and toxic stress (glutathione S-transferase, gonadal lipid peroxidation and DNA strand breaks), immunocompetence (phagocytic activity, hemocyte count and viability), reproduction (gonado-somatic index, gamete maturation, and vitellogenin-like proteins), energy status (temperature-dependent mitochondrial electron transport, and gonad lipids), and individual status (age, condition factor, and growth index). These responses were compared against population characteristics such as live clam density, number of empty shells, and sex ratio. The results show that clam density decreased with distance from the estuary (high salinity level) to upstream of the fjord (low salinity). There was no clear relationship between the number of empty shells and distance or site quality. Clam density values corrected against distance were significantly correlated with hemocyte viability, phagocytic activity, mitochondrial electron transport (MET), DNA damage in gonad, and temperature-dependent mitochondrial electron transport activity. A canonical analysis of the various groups of biomarkers revealed that population metrics were more strongly related with immunocompetence, followed by energy status and temperature-dependent mitochondrial electron transport activity. However, toxic stress biomarkers were strongly associated with energy status and reproduction. This was further confirmed by non-linear modeling using adaptive artificial neural networks (genetic selection and back propagation learning paradigms), where the following parameters were able to predict population parameters with <20% error: gonad maturation and somatic index, MET (at 4 degrees C), gonad LPO, DNA damage, and phagocytic capacity. Intertidal clam populations were influenced by a distance gradient effect (salinity), where immunocompetence, in addition to energy status, was the strongest physiological parameter related to clam population metrics.

Audit of acute myocardial infarctions at Saint James's Hospital, Dublin, from 1996 to 1999

Saint James' Hospital is a 650-bed tertiary referral hospital. An audit was performed of acute transmural myocardial infarctions for the years 1996 to 1999 inclusive. On average there were 2043 cardiology admissions annually, 9.8% of all hospital admissions. Acute transmural myocardial infarction was diagnosed in 178 patients annually, and was less common during the summer. The figure of 72% receiving revascularisation therapy (thrombolysis 67%, primary angioplasty 5%) compares favourably with 35% in 1992. The main reason for not receiving thrombolysis was late presentation (15%) with contraindications present in only 5%. The case fatality rate was 16% confirming the higher mortality in clinical practice than that of thrombolytic trials. The prescription of aspirin or warfarin (99%) and betablockers (67%) was in line with international trials. The use of angiotensin converting enzyme inhibitors (34%) and statins (28%) is similar to other studies but less than would be expected according to trial evidence.

Cushing's syndrome due to phaeochromocytoma secreting the precursors of adrenocorticotropin

Adrenal phaeochromocytoma rarely causes ectopic ACTH syndrome. We describe a 44-yr-old hypertensive woman who was Cushingoid and markedly pigmented. Laboratory studies indicated severe hypokalaemia, abnormal liver function tests, and random serum cortisols greater than 1660 nmol/L. Urinary catecholamines were markedly increased. An abdominal computed tomography scan showed a 4-cm left adrenal mass and an hypertrophied right adrenal. ACTH levels were elevated at 200 pmol/L, but ACTH precursors, which cross-react in the ACTH assay, were more highly elevated at 1625 pmol/L. The tumor cells cultured in vitro also secreted ACTH precursors, whereas ACTH levels were undetectable. Because the patient was highly pigmented, we measured circulating concentrations of alpha-MSH, which were undetectable and certainly insufficient to stimulate melanogenesis, suggesting that tumorderived ACTH precursors or ACTH were responsible for the pigmentation. A laparoscopic adrenalectomy resulted in remission of the Cushing's syndrome and dramatic reduction in the pigmentation. Before operation, treatment of the patient with metyrapone and replacement dexamethasone decreased cortisol from more than 1660 to less than 20 nmol/L. Surprisingly, this resulted in a decrease in ACTH precursors to 100 pmol/L and ACTH to 9.0 pmol/L. In vitro treatment of the tumor cells with dexamethasone for 24 or 40 h increased ACTH precursor secretion. In summary, this phaeochromocytoma causing Cushing's syndrome secreted primarily ACTH precursors, which seemed to cause the marked pigmentation. In vivo and in vitro evidence suggests that glucocorticoids induced ACTH precursor secretion.

Outcome of reflux therapy on pediatric chronic sinusitis

OBJECTIVE

The cause of pediatric chronic sinusitis is multifactorial, but nasal edema appears to be the initial pathologic step. The objective of this study is to evaluate gastronasal reflux as a possible cause of pediatric sinusitis.

METHODS

Thirty children with chronic sinusitis were believed to be appropriate candidates for functional endoscopic sinus surgery. Children were evaluated retrospectively for their response to reflux therapy with regard to their sinus symptoms and avoidance of sinus surgery.

RESULTS

Two of the 30 children were eventually excluded because they were taken to surgery for the specific purpose of contact point release. Chart review at 24-month follow-up indicated that 25 of the 28 children (89%) avoided sinus surgery.

CONCLUSION

After reflux treatment, the number of children requiring sinus surgery was dramatically reduced. The results of this preliminary pediatric study indicate that gastronasal reflux should be evaluated and treated before sinus surgical intervention.

Roentgen stereophotogrammetric analysis using computer-based image-analysis

The two-dimensional position of markers in radiographs for Roentgen Stereophotogrammetric Analysis (RSA) is usually determined using a measuring table. The purpose of this study was to evaluate the reproducibility and the accuracy of a new RSA system using digitized radiographs and image-processing algorithms to determine the marker position in the radiographs. Four double-RSA examinations of a phantom and 18 RSA examinations from six patients included in different RSA-studies of knee prostheses were used to test the reproducibility and the accuracy of the system. The radiographs were scanned at 600 dpi resolution and 256 gray levels. The center of each of the tantalum-markers in the radiographs was calculated by the computer program from the contour of the marker with the use of an edge-detection software algorithm after the marker was identified on a PC monitor. The study showed that computer-based image analysis can be used in RSA-examinations. The advantages of using image-processing software in RSA are that the marker positions are determined in an objective manner, and that there is no need for a systematic manual identification of all the markers on the radiograph before the actual measurement.

Dynamic model of oxygen transport for transcutaneous PO2 analysis

A dynamic model of oxygen transport through the outer skin layers and a polarographic sensor was developed for the analysis of transcutaneous oxygen tension (tcPO2). It provides a basis for quantifying the factors that determine the relationship between tcPO2 and arterial oxygen tension (PaO2). Model simulations show the importance of stratum papillare metabolic oxygen consumption; the oxygen permeability of the skin relative to that of the sensor membrane and electrolyte; and temperature and the oxyhemoglobin dissociation curve. These simulations were consistent with experimental data obtained by using microcathode transcutaneous oxygen sensors, which were placed on the skin of 10 healthy adults. Furthermore, the model indicates that accurate evaluation of arterial oxygen tension by using transcutaneous measurements requires continuous estimation of skin perfusion. On the basis of tcPO2 measurements made during arterial occlusion, simulations indicate that quantitative evaluation of the metabolic oxygen consumption of the viable skin tissues is possible only when the oxygen permeabilities of the skin and sensor are known.

Discourse comprehension and problem solving: decisions about the treatment of breast cancer by women across the life span

The 1st study examined the decision making and prose comprehension of 94 women interacting with an authentic, unfolding health scenario about breast cancer. The 2nd study involved questionnaire data focusing on the decisions made by 75 women who had been diagnosed with breast cancer. Two major findings emerged from this laboratory and survey research. First, older women sought less information when making treatment decisions about breast cancer. However, the outcome of those decisions were equivalent to those of younger women. Second, older women made these decisions faster than younger women. In addition, treatment decisions were related to prose processing, the type of information underlined as important while reading as well as the type of information remembered about various treatment options.

Discourse comprehension and problem solving: decisions about the treatment of breast cancer by women across the life span

The 1st study examined the decision making and prose comprehension of 94 women interacting with an authentic, unfolding health scenario about breast cancer. The 2nd study involved questionnaire data focusing on the decisions made by 75 women who had been diagnosed with breast cancer. Two major findings emerged from this laboratory and survey research. First, older women sought less information when making treatment decisions about breast cancer. However, the outcome of those decisions were equivalent to those of younger women. Second, older women made these decisions faster than younger women. In addition, treatment decisions were related to prose processing, the type of information underlined as important while reading as well as the type of information remembered about various treatment options.

Vestibular schwannoma in an only hearing ear

A vestibular schwannoma in an only hearing ear is a difficult management problem. A case is presented of a patient who had a Nucleus-22 channel device implanted into a nonfunctioning ear and auditory rehabilitation prior to resection of a large vestibular schwannoma in the contralateral ear.

Mycobacterium tuberculosis alters expression of adhesion molecules on monocytic cells

The host response to Mycobacterium tuberculosis is characterized by interactions between mononuclear cells, with recruitment and fusion of these cells culminating in granuloma formation. In addition, the host response to M. tuberculosis requires CD4+ T-cell reactivity, mediated by antigen-independent as well as antigen-dependent mechanisms. Thus, we hypothesized that cell adhesion molecules such as intercellular adhesion molecule 1 (ICAM-1; CD54) would participate in the response to infection with M. tuberculosis. Exposure of THP-1 cells derived from a monocyte/macrophage cell line to M. tuberculosis (1:1 bacterium/cell ratio) elicited a sustained increase (660% +/- 49% above resting level) in the expression of ICAM-1 that continued for at least 72 h. Neither the expression of vascular cell adhesion molecule 1 (VCAM-1; CD106) nor that of the integrins lymphocyte function-associated antigen 1 (LFA-1; CD11a/CD18) or CR3 (CD11b/CD18) was increased to a similar extent at corresponding time points. The increase in ICAM-1 protein expression was accompanied by an increase in steady-state mRNA (Northern [RNA] analysis). Neutralizing monoclonal antibodies directed against tumor necrosis factor alpha but not interleukin 1 alpha or interleukin 1 beta substantially abrogated the response to M. tuberculosis consistent with a paracrine or autocrine response. Continuous upregulation of the expression of ICAM-1 on mononuclear phagocytes induced by M. tuberculosis may mediate the recruitment of monocytes and enhance the antigen presentation of M. tuberculosis, thus permitting the generation and maintenance of the host response.

A new portable device for automatic controlled-gradient cryopreservation of blood mononuclear cells

Protection of the functional integrity of mononuclear cells stored in liquid N2 requires careful control of the freezing procedure. Consequently, optimal quality of cryopreserved cells is usually assured by freezing according to a specified time-temperature gradient generated by computer-controlled freezing devices. While such equipment offers large capacity and secures maximum survival and functional integrity of the lymphocytes upon thawing, it is quite costly and strictly stationary. We have previously developed and tested an alternative, manual device for controlled-gradient lymphocyte freezing, which has proved suitable for field conditions. We report here the development and testing of a similar micro-controller regulated device, allowing unattended and automatic controlled-gradient cell freezing. The equipment exploits the temperature gradient present between the liquid N2 surface and the neck in an ordinary liquid N2 refrigerator. The lymphocyte samples are placed in a small elevator, which is moved through the N2 gas phase by a stepper motor. Time and temperature are measured at regular intervals, and the position of the samples adjusted to ensure that the actual measurements closely match encoded ideal values. Results of assays of the functional integrity and phenotypic composition of human mononuclear cells frozen by the new system were comparable to those obtained when using cells frozen by a commercially available, stationary cell-freezing equipment, or fresh autologous cell samples tested in parallel. Furthermore, there was a good correlation between functional and phenotypic data obtained using frozen and autologous fresh samples of mononuclear cells. The equipment described is low weight and has low N2 consumption, and is thus suitable for the collection and cryopreservation of lymphocytes under field conditions. Furthermore, the technique provides an inexpensive alternative for researchers with a limited requirement for the simultaneous freezing of large quantities of cells.

The effects of 24% paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride) on hemodynamics, blood gases, plasma lactate and plasma catecholamines in dogs

The cause of death after ingestion of a large dose of paraquat is unclear. We investigated the cardiovascular effects of paraquat injection in 7 dogs that were anesthetized with urethane and alpha-chloralose and maintained on controlled ventilation. After control measurements, paraquat (20 mg/kg) was injected iv. Average concentrations of plasma paraquat were 128 micrograms/ml at 15 min (point 1) and 44 micrograms/ml at 4 hr. The average time of survival was 5.5 +/- 2.2 hr. Comparison was made of control values, 15 min (point 1), and 2.5 +/- 1.0 hr before death (point 2). Pulmonary capillary wedge pressure (+33%) and pulmonary vascular resistance (PVR) (+28%) increased, but no change occurred in mean arterial pressure (MAP) or cardiac output (CO) at 15 min. Mean arterial pressure (-50%) and cardiac output (-61%) decreased, while total vascular resistance (+56%) and PVR (+256%) were increased at point 2. Arterial pH decreased from 7.394 and 7.307 (point 1) to 7.143 (point 2). The concentration of plasma catecholamines and lactic acid increased significantly at both points 1 and 2. Renal, adrenal and myocardial tissues were studied by light and electron microscopy. The outstanding feature was early swelling of mitochondria and disruption of the contents in the presence of intact mitochondrial membrane.

Quantitative and qualitative changes in LH secretion following pulsatile GnRH therapy in a man with idiopathic hypogonadotrophic hypogonadism

The pattern of bioactive and immunoreactive LH secretion before and during pulsatile GnRH therapy (18 micrograms/90 min) in a hypogonadotrophic hypogonadal male has been studied. Before treatment the patient was azoospermic and had low testosterone (1.2 nmol/l) with low and apulsatile immunoreactive LH (1.9 +/- 0.2 IU/l) and FSH (1.4 +/- 1.9 IU/l) levels. There was no detectable LH bioactivity. During the first 24 h of GnRH therapy there was a small increase in immunoreactive (5.4 +/- 0.8 IU/l) and bioactive (6.7 +/- 1.3 IU/l) LH, with an irregular pattern and little effect on testosterone production (2.2 nmol/l). Within 1 week of treatment both bioactive (30.5 +/- 6.8 IU/l) and immunoreactive (13.6 +/- 1.5 IU/l) LH levels were above the normal range and the pattern of secretion was pulsatile. The bioactive to immunoreactive (B:I) LH ratios within the pulses (2.6 +/- 0.3) were higher (P less than 0.01) than between pulses (1.97 +/- 0.1) and the testosterone concentration (17.8 +/- 2.1 nmol/l) was now normal. At one month LH secretion was similar and testosterone pulses of high amplitude were evident corresponding to high-amplitude bioactive LH pulses. By 3 months mature spermatozoa (1.3 x 10(6)/ml) were seen in the patient's semen. The pattern of LH secretion was pulsatile but the levels of bioactive (13.1 +/- 3.6 IU/l) and immunoreactive (9.5 +/- 1.3 IU/l) LH decreased towards the normal range reflecting maturation of the testicular feedback control at the pituitary level. This effect was more pronounced on bioactive rather than immunoreactive LH secretion (57% vs 32% relative decrease). At 6 months LH levels were similar and the sperm count was normal (34 x 10(6)/ml).