Anti-tuberculous therapy and acute liver failure

The incidence of tuberculosis has been increasing since 1987, exposing a greater number of patients to the risks of three potentially hepatotoxic drugs, isoniazid, rifampicin, and pyrazinamide. Awareness of potentially severe drug hepatotoxic reactions is vital because fulminant hepatic failure is a devastating and often fatal condition without liver transplantation. We report four cases of fulminant hepatic failure caused by rifampicin, isoniazid, or both. These cases highlight the need for stricter adherence to and review of current guidelines on liver function tests after starting anti-tuberculous therapies.

Apnea and factitious illness (Munchausen syndrome) by proxy

OBJECTIVE

Munchausen syndrome by proxy (MSP) is recognized in the differential diagnosis of apparent life-threatening events, but the early signs and the full spectrum of this presentation are not well recognized. We aim to describe MSP presenting with apnea to illustrate this spectrum and the evolution in our management over a period of 10 years.

PATIENTS AND RESULTS

Eleven children in five families seen in one institution and assessed by one team are described in detail. The children had apnea and/or pallor, but with a wider age range than usually seen with apparent life-threatening events, sometimes associated with other injuries, and a large percentage of parents were health care providers. In no case was apnea witnessed by health care professionals other than the parents. There were frequent disagreements in management between professionals and, consequently, delays in considering the diagnosis at first. There were two deaths. A team developed, allowing the diagnosis of MSP to be considered sooner and the cases to be assessed and managed consistently.

CONCLUSION

MSP is part of child abuse, and it needs to be recognized by all physicians. Family assessment is required and the development of a team interested in MSP facilitates assessment and management.

The measurement of thoraco-abdominal asynchrony in infants with severe laryngotracheobronchitis

Retractions of the lower ribcage (chest wall distortion [CWD]) during inspiration are frequently observed with moderate to severe respiratory disease in the infant. Laryngotracheobronchitis (LTB) results in a reversible partial airway obstruction with severe CWD. We wished to measure the motion of the chest wall during distortion to determine the changes in minute ventilation (VE) and to evaluate this clinical sign as a means of assessing disease severity. The respiratory inductance plethysmograph was used to determine the distortion of the lower chest wall, and distortion was correlated with VE, measured at the mouth, in six infants with severe LTB and ventilatory failure. As the conditions of these infants improved, the CWD decreased with decreasing transcutaneous carbon dioxide tension (tcPCO2), VE increased from 0.27 +/- 0.12 L.min-1 x kg-1 at a tcPCO2 of 64 mm Hg to 0.64 +/- 0.06 L.min-1 x kg-1 when the tcPCO2 had fallen to 28 mm Hg. Over the same change in tcPCO2, the tidal volume (VT) increased from 4.8 +/- 0.5 ml.kg-1 to 15.7 +/- 1.4 ml.kg-1. In the most severe disease state, the excursion of the chest wall (as an inductance) was -14 +/- 3 mV in severe obstruction, but increased to 75 mV +/- 4 mV with resolution of the illness. The timing and vector of movement of the abdomen and chest wall were expressed as a Lissajous figure, which is measured as a phase angle. The severity of the disease process, as determined by tcPCO2 was directly related to the phase relationship, and thus reflected both VE and VT. The severity of the CWD may be assessed rapidly by the use of Lissajous figures.

Munchausen's syndrome by proxy. The question of psychiatric illness in a child

We believe the case of a boy whose mother insisted he was psychotic is the first report considering psychiatric illness in a child as part of the Munchausen's syndrome by proxy (MSP) complex.

Histamine challenge in young children using computerized lung sounds analysis

The use of the histamine challenge test (HCT) for the diagnosis of asthma has so far been limited to older children who can perform spirometry consistently. Recently, wheeze detection by tracheal auscultation with analog recording into a tape recorder has been utilized in young children in place of spirometry. Wheezing can also be identified using computerized lung sounds analysis (LSA) by a typical pattern on spectral analysis. Our aim was to develop a practical computerized system in which the response to histamine could be identified in an objective manner and documented on hard copy. Lung sounds were recorded with a Hewlett-Packard HP 21050A contact sensor placed over the right upper anterior chest. Sounds were amplified, band-filtered (50 to 2,000 Hz), and digitized at a sampling rate of 5.5 kHz into a Macintosh SE computer, and spectral LSA was performed. To validate our method, six older children (ages 9 to 16 years) with mild or moderate asthma underwent HCT. The identification of typical wheezing pattern (discrete, high-amplitude power peaks) on LSA was compared to 20 percent fall in FEV1 (PC20) and symptoms (cough, wheeze, chest tightness). In five children, the histamine concentration required to produce the characteristic wheezing pattern on LSA was half that required to produce a 20 percent fall in FEV1. In the sixth patient, wheezing on LSA and PC20 occurred at the same histamine concentration. To determine the technique's applicability to young children, we then studied six young asthmatic children (age 2 to 5 years). All children showed the wheezing pattern at a histamine concentration of 25 percent or 50 percent (one or two steps prior) to that producing symptoms (cough, wheeze, chest tightness) or wheezing on tracheal auscultation. Six age- and sex-matched nonasthmatic children (control subjects) did not show this pattern on LSA and had no symptoms or tracheal wheeze with HCT. We describe a sensitive method enabling application of HCT to young children who are unable to perform spirometry. This method is as sensitive as, and often more sensitive than, conventional PC20 with spirometry or tracheal auscultation.

Intensive care course and outcome of patients infected with respiratory syncytial virus

PICU admissions of 97 children positive for respiratory syncytial virus on fluorescent antibody screening were reviewed; 68% of 44 patients without history of preceding disease (Group I) and 79% of 53 patients with preceding pulmonary, cardiac, or other disease (Group II) required ventilation. In Group I ventilated children weighted significantly less (P = 0.001) and were of lower chronological (P = 0.02) and post-conceptional ages (P = 0.02) than those not ventilated. Eighteen infants ventilated for apnea weighted significantly less (P = 0.003), were more often born at less than or equal to 37 weeks gestation (P = 0.001) and were at lower post-conceptional age than 11 infants ventilated for progressive respiratory deterioration. There was no significant difference in mean weight, chronological age, post-conceptional age, CO2, or pH between 12 admissions with BPD who required ventilation for RSV infection and 5 who did not require ventilation. Ribavirin administration to five ventilated patients with BPD did not significantly alter the duration of intubation of PICU stay. Six patients with cardiac disease required longer periods of ventilation than others (Group I, P = 0.001; all others in Group II, P = 0.04). No deaths occurred in Group I, while 6 of 53 (11%) patients in Group II died. In this series immuno compromise placed patients at greatest risk of dying. Mechanical ventilation can be safely managed in previously healthy, RSV infected infants and should be initiated before significant cardiorespiratory compromise arises.

Comparison of three forward mutation systems in Saccharomyces cerevisiae for sensitivity to polycyclic and heterocyclic compounds

Forward mutation to cycloheximide resistance, L-canavanine resistance and DL-alpha-aminoadipic acid resistance in Saccharomyces cerevisiae wild-type strain S7a was tested for sensitivity to nine mutagens in treat-and-plate assays. Eight of these agents, 2-aminofluorene, 2-acetylaminofluorene, benzo[a]pyrene, benzidine, cyclophosphamide, acriflavine, 7,12-dimethylbenz[a]anthracene and 2-aminoanthracene were known or suspected to be difficult to detect whilst one, methyl methanesulphonate, was known to be very active in yeast. Forward mutation to cycloheximide resistance was, overall, the most sensitive system, detecting all nine agents under optimal conditions, although neither benzidine nor benzo[a]pyrene were consistently positive. Mutation to adipic acid resistance occasionally gave responses superior to those at the cycloheximide loci, but mutation to canavanine resistance was never more sensitive than the cycloheximide resistance system. We conclude that forward mutation in strain S7a using both cycloheximide and adipic acid resistance loci is capable of detecting the genetic effects of a range of polycyclic and heterocyclic compounds with greater sensitivity than is seen in other published gene mutation assays with yeast. Although sensitivity is much lower than in bacterial assays, such yeast assays provide a reasonable alternative to bacterial genotoxicity screening for agents such as potent bactericides.

Congenital tracheal stenosis in Pfeiffer syndrome

We report an infant with Pfeiffer syndrome (acrocephalosyndactyly type V) and a solid cartilaginous trachea lacking rings. This airway abnormality has been reported in a child with Crouzon syndrome but has not been described in Pfeiffer syndrome.

Enzyme studies in human transitional cell carcinoma of the urinary bladder

The activities of six enzymes of carbohydrate metabolism were estimated in tissue samples from 99 patients with transitional cell carcinoma of the urinary bladder undergoing transurethral resection. The results were analysed according to the stage of the disease and the malignancy grade of the carcinoma. There were statistically significant differences in the activities of three enzymes between various stages and grades. The activities of phosphofructokinase (PFK), alpha-glycerolphosphate dehydrogenase (alpha-GPDH), and phosphohexose isomerase (PHI) showed significant decreases with increased stage and grade. Of the total of 64 patients with superficial disease at presentation, five developed progressive disease during the course of this investigation. The activities of the three enzymes in these patients were compared to the median values for the group of patients with superficial disease. The activity of PFK was observed to be below the median value in all the five patients whereas the activities of alpha-GPDH and PHI showed similar patterns in four of the five patients. These preliminary data indicate that, in association with established clinical parameters, the measurement of the activity of these three enzymes may prove useful in selecting patients with an increased potential for developing progressive disease.

Home oxygen therapy. Outcome of infants discharged from NICU on continuous treatment

Forty-four oxygen-dependent infants were discharged home in oxygen from an NICU during an 8-year period. Survivors were followed for 3 years. The infants' discharge diagnoses were bronchopulmonary dysplasia (BPD) (39), sleep apnea (2), and congenital cardiac defects (3). The five infants who had diagnoses other than BPD all died, but 34 of 39 infants with BPD survived. Supplemental oxygen was discontinued at a mean age of 13.4 months. The infants with BPD experienced health, growth, nutritional, neurodevelopmental and sensory problems that necessitated frequent rehospitalizations and utilization of a variety of medical and support services.

Cavopulmonary anastomosis as long-term palliation for patients with tricuspid atresia

Prior to 1970, most patients with tricuspid atresia (TA) and reduced pulmonary blood flow were palliated by means of a systemic to pulmonary artery shunt (SPAS). In Birmingham between 1967 and 1988, 19 patients with TA (aged 16 days to 23 years, mean 3.8 years) have undergone side-to-side cavopulmonary anastomosis (CPA) with preservation of pulmonary artery continuity. One had undergone a previous right Blalock-Taussig shunt and in 1 patient with left and right SVCs, bilateral CPAs were performed. Nine patients were less than 1 year old at the time of operation. There were no operative deaths. One late death occurred due to pneumonia. Immediate clinical improvement occurred in all cases. Six symptomatic patients subsequently required further surgery (mean interval between operations 8.9 years, range 4.6-14.2 years). The remaining 12 patients have recently been reviewed. Mean follow-up was 9.5 years (range 5 weeks to 21 years). Exercise tolerance remains good (9 in NY-HA Class 1 or 2) and resting transcutaneous oxygen saturations are higher (mean 85%, range 70%-89%) compared with preoperative values (P less than 0.01). In small children, CPA avoids the complications of SPAS and, in some patients, may itself achieve adequate long-term definitive palliation.

Divergent effects of interferons on the growth of human benign prostatic hyperplasia cells in primary culture

Epithelial cells from human benign prostatic hyperplasia tissues were grown in primary cultures for up to 21 days and the effects of interferons on the growth of the cells were investigated. Interferon-alpha (Wellferon) showed growth inhibition both in the presence and in the absence of 3 x 10(-10)M testosterone propionate (TP) whereas interferon-gamma stimulated growth in a dose dependent manner under similar conditions. Interferon-beta had little effect on growth at the dose levels used in the study. The growth inhibition by interferon-alpha can be induced after stimulation of growth is achieved either with TP or with interferon-gamma. Implications of these findings for clinical use of these lymphokines is discussed.

Diffuse necrotizing tracheobronchitis: an acute and chronic disease

Necrotizing tracheobronchitis (NTB) is characterized by acute episodes of airway obstruction, hypercarbia, and lack of chest movement in mechanically ventilated neonates. Emergency bronchoscopic removal of necrotic tissue is essential for survival. Although postmortem lesions extend into smaller bronchi, survivors have not demonstrated residual tracheobronchial abnormalities. Two infants were treated successfully for NTB but succumbed to diffuse tracheobronchial strictures with progressive pulmonary hyperinflation. A third neonate with esophageal atresia and left pulmonary agenesis developed NTB. Despite initial postbronchoscopic improvement, the infant died at age 6 weeks with diffuse obstructing NTB. All three infants required endotracheal intubation and mechanical ventilation. High-frequency jet ventilation was not used. Tracheal cultures for fungi, bacteria and viruses were negative. Successful treatment of NTB may be followed acutely by recurrence of NTB and chronically by diffuse tracheobronchial strictures and emphysema.

The effects of interferons on the activity of alpha-glycerolphosphate dehydrogenase in benign prostatic hyperplasia cells in primary culture

Human benign prostatic hyperplasia (BPH) tissues were obtained from patients undergoing transurethral resection of the prostate and viable cells from these were successfully maintained in primary cultures grown on collagen gel. The prostatic origin of the cells was confirmed by the measurement of prostate specific acid phosphatase and by scanning and transmission electron microscopy before and after immunostaining with human prostate specific antigen-antibody. The cell cultures were treated with various interferons (IFNs), both in the presence and absence of testosterone propionate (TP), for 72 hours and the activities of seven enzymes of carbohydrate metabolism were estimated in the cytosolic fraction of the cells. Treatment with TP induced a significant decrease in the activity of alpha-glycerolphosphate dehydrogenase (alpha-GPDH). Using this enzyme activity as a marker, the effects of various types of IFNs were investigated. IFN-alpha (wellferon) increased the activity of the enzyme both in the presence of one microgram./ml. of TP and in its absence whereas IFN-gamma inhibited the activity under similar conditions. The effect of treatment with IFN-beta in the presence of TP was biphasic in that there was an increase in the activity of the enzyme at the lowest concentration while at higher concentrations an inhibition of enzymic activity was observed. In the absence of TP IFN-beta inhibited the activity. The significance of these findings in terms of the clinical usefulness of IFNs is discussed and it is postulated that IFN-alpha (wellferon) might be effective in the treatment of metastatic carcinoma of the prostate in selected patients.

Antireflux surgery in infants with bronchopulmonary dysplasia

We reviewed the medical records of nine infants with severe bronchopulmonary dysplasia and gastroesophageal reflux who underwent fundoplication-gastrostomy surgery. All the infants were born prematurely, required preoperative mechanical ventilation, and were failing to thrive. The operative procedure was well tolerated by all the infants. Seven patients were extubated by day 11, and two patients required long-term ventilation. There were two postoperative deaths, both attributed to acute respiratory deterioration followed by cardiorespiratory failure. The postsurgical respiratory response was observed to be a rapid decrease in oxygen requirements and an absence of further aspiration episodes. A mean decrease of 0.14 in fractional inspired oxygen concentration was noted by 30 days postoperatively, and by 180 days the decrease in fractional inspired oxygen concentration was 0.22. All infants were fed by gastrostomy by postoperative day 4, with no evidence of clinical reflux. The nutritional response was noted to be an increase in growth velocity with increasing age (ie, catch-up growth) and ease of feeding. At both 30 and 180 days postoperatively, the mean growth velocity was more than double the preoperative growth velocity. In addition, ease of postoperative feeding reduced the nursing care requirements and allowed earlier discharge from hospital. Fundoplication and gastrostomy is effective in facilitating growth and feeding in addition to decreasing oxygen requirements in infants with severe bronchopulmonary dysplasia and gastroesophageal reflux.

The activity of phosphohexose isomerase in primary breast carcinomas and response to chemotherapy in patients with metastatic disease

The activity of phosphohexose isomerase [PHI] was measured in 48 primary carcinomas from patients with breast cancer, and its usefulness as a predictor of response to cytotoxic drugs at the metastatic stage was evaluated. There was a statistically significant difference in the activity of PHI between responders and non-responders to these treatments. These preliminary findings are currently being evaluated in an extended series.

Scarves and engines

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Deoxyribonucleic acid (DNA) content of primary carcinoma and response to endocrine or cytotoxic drug therapies in patients with advanced breast cancer

The DNA content of primary carcinomas was estimated colorimetrically in 111 patients with carcinoma of the breast who subsequently developed metastatic disease. The data were analysed to investigate whether these measurements will assist clinicians in predicting: survival from mastectomy or recurrence, the likelihood of response to the first endocrine or the first cytotoxic drug therapy, duration of response amongst responders to these treatments, and time to treatment failure (TTTF). The DNA content of primary carcinomas failed to predict the clinical course of the disease for patients who underwent endocrine treatments. In patients who were treated by cytotoxic drug therapies, only the duration of response amongst responders to these therapies was significantly shorter in cases where the DNA content was high. The DNA content of carcinomas failed to give any useful information on other parameters. It is concluded that these measurements are unlikely to be of prognostic value in these cases.

Adverse effects of racemic epinephrine in epiglottitis

Acute epiglottitis, a potentially fatal disease, may be difficult to diagnose if the presentation is atypical. We present three such patients who were initially diagnosed as acute laryngotracheitis. They deteriorated rapidly after administration of racemic epinephrine via nebulizer. We caution that: diagnosis of acute epiglottitis should be considered in similar patients; and appropriate precautions must be taken prior to visualization of the airway.

The effects of the administration of tamoxifen, ethynyloestradiol, and prednisolone on the activities of certain enzymes of carbohydrate metabolism in primary human breast carcinomas in vivo

Postmenopausal patients with primary breast cancer were treated with tamoxifen, ethynyloestradiol or prednisolone for up to 12 days before mastectomy and the effects of pretreatments with these drugs on the activities of phosphofructokinase (PFK), 6-phosphogluconate dehydrogenase (6PGDH) and alpha-glycerolphosphate dehydrogenase (alpha-GPDH) in the carcinomas were compared with age, stage and menopausal status matched untreated controls. The administration of tamoxifen or prednisolone resulted in a significant increase in the activity of alpha-GPDH and the alpha-GPDH/6PGDH ratio, whereas ethynyl-oestradiol treatment produced a significant decrease in the activity of the enzyme and the ratio. When tamoxifen and ethynyl-oestradiol were administered together, it was found that tamoxifen failed to reverse the oestrogen-induced reduction in the activity of alpha-GPDH. Since increased activity of the enzyme or a higher alpha-GPDH/6PGDH ratio are associated with a lower risk of recurrence (Deshpande et al., 1981), it is postulated that the beneficial effects of tamoxifen or prednisolone in terms of prolongation of the relapse free interval might be mediated via alterations in the activity of alpha-GPDH in micrometastases. The activities of PFK and 6PGDH remained unaffected by these treatments.

Sodium cromoglycate-induced changes in the dose-response curve of inhaled methacholine in cystic fibrosis

Fifteen patients with cystic fibrosis (CF) (aged 7 to 20 years, mean 12.3 years), all known to respond to a methacholine (MCh) challenge, had two MCh challenges preceded by an inhalation of normal saline on one occasion and sodium cromoglycate (SCG) on another. The variation in baseline FEV1 between the two days of the study was 10% or less in all patients. Four patients (27%) gained significant protection with SCG against this non-allergenic challenge and, in two patients, SCG completely blocked the effects of MCh. These results would support clinical studies of SCG in some patients with CF but not the widespread use of SCG in CF.

Transient neutral fat steatorrhea, elevated sweat chloride concentration, and hypoparathyroidism in a child with celiac disease

A patient with celiac disease and the unusual features of transiently elevated sweat chlorides, reversible exocrine pancreatic insufficiency, symptomatic hypocalcemia/hypomagnesemia, and transient secondary hypoparathyroidism is presented along with a brief discussion of the physiologic mechanisms thought to underlie their development.

Drug effects on certain enzymes of carbohydrate metabolism in MCF-7 cells in culture

The effects of treatments with ethinyl-estradiol, tamoxifen, prednisolone, cyclophosphamide, methotrexate, 5-fluorouracil and Adriamycin on the activities of PFK, 6PGDH, alpha-GPDH and alpha-GPDH/6PGDH ratios were investigated in MCF-7 cells in monolayer cultures. The following findings are recorded. Both ethinyl-estradiol and prednisolone failed to induce alterations in the activities of these enzymes. Tamoxifen increased the activities of PFK, alpha-GPDH and alpha-GPDH/6PGDH ratios whereas ethinyl-estradiol inhibited the tamoxifen-induced rise in the activity of PFK. Treatment with cyclophosphamide alone was without any effect but in combination with either methotrexate or 5-fluorouracil induced increases in the activities of 6PGDH and alpha-GPDH. Adriamycin at a lower dose increased the activities of 6PGDH and alpha-GPDH and the alpha-GPDH/6PGDH ratio and decreased the activity of PFK. At a higher dose level it reduced the activities of all the enzymes whilst increasing the alpha-GPDH/6PGDH ratio. These data encourage us to undertake a project to test the sensitivity of individual tumours to these drugs in vitro thereby enabling the selection of appropriate drugs for adjuvant therapy.

Deoxyribonucleic acid (DNA) content of carcinomas and prognosis in human breast cancer

DNA content was estimated in 705 breast carcinomas from patients with stage I or stage II disease undergoing mastectomy, to investigate whether it would predict the clinical course of the disease. The patients were then followed for up to 84 months during which time 166 of them developed recurrences. There were no statistically significant differences in the DNA content of carcinomas between stage I and stage II patients or between those with various numbers of involved nodes. The tumours from pre-menopausal patients as a group had significantly higher DNA content than those from post-menopausal cases. There was a gradual rise in DNA content with the malignancy grade of the carcinoma which showed significant differences between Grades I and III and between II and III. Life-table analyses showed that the measurement of DNA would not be an aid to prognosis. Furthermore, when the data were stratified according to menopausal status, stage, malignancy grade or numbers of lymph nodes involved, the results indicated that these estimation do not add significantly to the information obtained through established prognostic factors. Survival data were available on III patients with recurrent disease. There were no significant differences in tumour DNA content between short- and long-term survivors. It is concluded that these measurements seem unlikely to be a prognostic factor in human breast cancer.

Transpyloric feeding in the newborn: use in neonates with and without respiratory failure

In a peripheral maternity hospital providing Intensive Care for 5274 deliveries per annum, NJ feeding was attempted, in one year, in 57 neonates. One third of these weighed less than 1500 g at birth and 41 (71.9%) had respiratory disease. A standard technique, and a commercially available tube was used, and the tube was passed to the jejunum within 24 hours in 46 (80.7%) of the babies. NJ feeding was continued for varying periods, up to 50 days. The volume of milk given varied with the duration of the feed but feeds of up to 244 ml of milk/Kg body weight/day were achieved. Thirty-eight (66.6%) of the babies regained their birthweight by 20 days and major complications were uncommon. We have shown that NJ feeding can be used in low birthweight babies with serious respiratory illness, even when resources are limited.

Frequency and severity of apnoea in lower respiratory tract infection in infancy

Twenty four hour recordings of heart rate and respiration were made on 60 infants with lower respiratory tract infection (LRTI) during the acute phase of the illness, on 20 infants with upper respiratory tract infection (URTI) and on 21 control infants. Infants with LRTI and URTI had more apnoeic episodes of longer than 10 seconds compared with controls. The length of apnoeic episodes was greatest in the LRTI group but their frequency decreased with age. In both the LRTI and URTI groups apnoea was associated with bradycardia but the LRTI group also suffered an appreciable number of episodes of bradycardia without apnoea.

Enzyme studies in human prostatic tissues

The activities of six enzymes associated with carbohydrate metabolism were measured in 24 benign prostatic hyperplasias and 29 carcinomas of the prostate with the intention of investigating whether these measurements might eventually predict the clinical course of the disease. The following findings are recorded: the activities of PFK, alpha-GPDH and PHI were significantly lower in carcinomas. Comparison between well and poorly-differentiated carcinomas indicated a significantly lower activity of 6PGDH and higher alpha-GPDH/6PGDH ratios in the latter. These findings are the opposite of those observed in carcinomas of the breast.

Corticotropin and morphine interaction in the regulation of phosphofructokinase activity in rat mammary gland

The roles of corticotropin and morphine in the regulation of phosphofructokinase (PFK) activity in rat mammary glands were investigated by the administration of corticotropin, morphine and dexamethasone. Corticotropin increased the activity of PFK in the mammary glands of intact and hypophysectomised animals but was without any effect in tissues from ovariectomised and adrenalectomised animals. Morphine administration resulted in a significant decrease in the enzyme's activity in intact animals only. A combined dose of corticotropin and morphine significantly reduced the corticotropin-induced increase in the activity in both intact and hypophysectomised animals. Dexamethasone treatment resulted in a significant increase in the activity in hypophysectomised and ovariectomised plus adrenalectomised animals and morphine was able to reduce the glucocorticoid-induced rise. It is postulated that endogenous opioids might be playing a dual role in the regulation of glycolysis by inhibiting the release of corticotropin and regulating the action of glucocorticoids at the cellular level in the mammary gland.

Functional validation of projection topography in the nigrostriatal dopamine system

Anatomical investigations have revealed that the nigrostriatal pathway is topographically organised. In two experiments, nigrostriatal topography was investigated with catecholamine specific procedures, using paradigms which reflect the functional activity of dopaminergic neurones. Data were analysed with the intention of discovering possible relationships between the mesencephalic location of stimulating electrodes or injection cannulae, the extent and location of dopamine histofluorescence depletion within the striatum, and the effects of amphetamine and apomorphine on rotational behaviour. In animals pretreated with 250 mg/kg alpha-methyl-p-tyrosine it was found that unilateral stimulation with medially-placed nigral electrodes produced maximal depletion of dopamine histofluorescence in anterior dorso-medial regions of the striatum, while laterally-located electrodes principally depleted posterior, ventro-lateral areas. In the second experiment, 2 micrograms of 6-hydroxydopamine in a volume of 0.5 microliter was injected unilaterally at varying loci within the ventral midbrain of animals pre-treated with desmethylimipramine (25 mg/kg). It was discovered that the lateral injection coordinate was significantly associated with both the extent and location of the depletion of dopamine-related fluorescence from the ipsilateral striatum. Rotational behaviour, induced by dopamine-agonists was related firstly, to the overall extent of dopamine depletion from the striatum, and secondly, the contraversive turning induced by apomorphine in particular was related to the dorsoventral coordinate of the mesencephalic 6-hydroxydopamine injection. The results provide functional validation for the pattern of topographical projection within the nigrostriatal dopaminergic system proposed on the basis of intracellular tracing techniques.

Photometric assessment of glyoxylic acid-induced fluorescence of dopamine in the caudate nucleus

New procedure for quantitative photometric assessment of glyoxylic acid-induced fluorescence of dopamine in the caudate nucleus are presented. A recently published cryostat method was used to process a series of 24 micrometer sections taken from the caudate nucleus of each animal. Fluorescent light contained within a circular field (0.8 mm diameter) was measured photometrically. Several defined positions within the caudate nucleus on each tissue section were selected for measurement. Thus, a grid of measurements taken throughout the caudate nucleus provided a three-dimensional description of fluorescence intensity within this structure on both sides of the brain. Several experiments were performed to evaluate both the reliability and validity of these procedures as an index of the relative regional content of dopamine within the caudate: (1) the relative distribution of fluorescence intensity within the mouse striatum was in good agreement with previously reported distributions based on biochemical determination of regional dopamine levels within the rodent brain; (2) pharmacological manipulation of dopamine levels with gamma-butyrolactone and alpha-methyl-p-tyrosine combined with amphetamine produced predictable changes in the fluorescence intensity measurements of mouse caudate relative to untreated controls; (3) in rats pre-treated with alpha-methyl-p-tyrosine, unilateral electrical stimulation of the substantia nigra caused overall differences in fluorescence intensity between the caudate nucleus on each side of the brain, which were a function of both the duration of stimulation and the stimulating pulse frequency; (4) local injections of 6-hydroxydopamine unilaterally into the ventral tegmentum of animals pretreated with desmethylimipramine caused significant reductions in the intensity of fluorescence recorded from the ipsilateral striatum. It is concluded that the photometric procedures presented in this report constitute a significant improvement in the description of regional variations in the intensity of dopamine-related fluorescence in the caudate nucleus.

Thallium myocardial perfusion scans for the assessment of right ventricular hypertrophy in patients with cystic fibrosis. A comparison with other noninvasive techniques

The incidence of right ventricular hypertrophy in 32 patients with cystic fibrosis was studied using thallium 201 (TI-201) myocardial perfusion scans, and compared with other noninvasive techniques including electrocardiography, vectorcardiography, and M-mode echocardiography. The patients (mean age, 17.3 yr; range, 7 to 33) had a wide range of clinical and pulmonary abnormalities (mean Shwachman-Kulczycki score, 66.6). In the total study group, TI-201 scans, like the vectorcardiograms and the M-mode echocardiograms, gave a surprisingly high proportion of positive predictions for right ventricular hypertrophy (RVH) (44%). The correlations with all other noninvasive methods were uniformly poor, so caution must be exercised in using this technique to predict early RVH in order to follow the natural history of cor pulmonale in cystic fibrosis. At the time of the study, 6 patients had clinical evidence of right ventricular failure, and in this disease setting must have had RVH. In 3 patients, RVH was confirmed at autopsy, and it was successfully predicted by TI-201 scans in 5 of the 6 patients. The false negative scan may have been due to regional myocardial ischemia secondary to severe right ventricular failure. In contrast, the vectorcardiogram, using Fowler's new criteria, made a successful prediction of RVH in all 6 patients, and the electro cardiogram in only 3. Although the M-mode echocardiogram was abnormal in all patients, it would have predicted RVH (with increased right ventricular anterior wall thickness) in only 1 patient. We concluded that TI-201 myocardial perfusion cans are good at confirming RVH in cases with established right ventricular failure, but have no advantage over vectorcardiographic assessments, which are logistically easier to perform and carry no radiation risks.

Further observations on the hormonal regulation of alpha-glycerolphosphate dehydrogenase in rat mammary gland: a possible role for prolactin and thyrotropin

The roles of prolactin and thyrotropin (TSH) in the regulation of alpha-glycerolphosphate dehydrogenase (alpha-GPDH) activity in rat mammary gland were investigated by the administration of thyroid releasing hormone, bromocriptine, prolactin, TSH and triiodothyronine (T3). TRH administration failed to induce alterations in the glands from intact animals but stimulated the activity in castrated and adrenalectomized animals. Bromocriptine administration was without any effect in either group of animals. Administration of ovine prolactin to hypophysectomized rats did not affect the activity, on the other hand, treatment with either TSH or T3 resulted in a highly significant increase in the activity. Combined administration of prolactin and TSH to hypophysectomized animals showed that prolactin is capable of partially inhibiting the TSH-induced increase. It is suggested that glucocorticoids exert primary control over the enzyme's activity with the pituitary hormones only playing a permissive role in its regulation.

Evidence for the participation of opioids in the regulation of carbohydrate metabolism in rat mammary glands

The possible involvement of opioids in carbohydrate metabolism in rat mammary glands was investigated by studying the effects of administration of morphine and naloxone on six enzymes. Morphine inhibited phosphofructokinase (PFK) and stimulated phosphohexose isomerase (PHI) activities. Nalozone treatment alone, to both intact and ovariectomized/adrenalectomized animals, resulted in stimulation of PFK and inhibition of PHI activities. A combined dose of morphine and naloxone to intact animals showed that the opiate antagonist was able to reverse the morphine-induced changes. Evidence is presented to show that the changes observed in PHI activity may be the result of the indirect action of opioids on luteinizing hormone releasing hormone. However, the changes observed in PFK activity might be the result of direct action of opioids. Failure to observe changes in enzyme acstivities after naloxone treatment of hypophysectomized animals suggests the opiate antagonist might be acting on the pituitary gland to block the release of endorphins.