Liver and lung transplantation in cystic fibrosis: an adult cystic fibrosis centre's experience.

Liver disease develops in one-third of patients with cystic fibrosis (CF). It is rare for liver disease to have its onset after 20 years of age. Lung disease, however, is usually more severe in adulthood. A retrospective analysis was performed on nine patients. Three patients required lung transplantation approximately a decade after liver transplant, and another underwent combined liver and lung transplants. Four additional patients with liver transplants are awaiting assessment for lung transplants. One patient is awaiting combined liver and lung transplants. With increased survival in CF, several patients may require more than single organ transplantation.

Using a nursing protocol to assure equitable delivery of cancer-related prevention services.

A nurse-administered, protocol-driven model (NP) for preventive services delivery was compared with a traditional physician reminder (PR) model with nursing back-up among 473 patients attending Internal Medicine and Family Medicine clinics. A total of 240 patients were randomized to the NP group and 233 to the PR group. Demographic characteristics including gender [71% female (NP) and 71% female (PR)], race (78% and 75% African American, respectively) and age (numbers of persons aged 18-54, 55-64 and 65+ years) were similar in each group. In the NP group 244/244 screening tests for breast, cervical and colon cancers and alcohol abuse were initiated or completed by nurses, while in the PR group 110/215 (51%) were initiated or completed by physicians. The NP group received 552/552 counseling services from nurses for tobacco, alcohol, nutrition, exercise and prostate screening, while in the PR group, physicians delivered 10% of the needed services (56/560). Aside from counseling for prostate cancer screening, which was 100% in both the NP and PR groups, all other between-group differences for each service were significant at the level of p<0.001. Results show the feasibility of a nursing protocol for initiating equitable cancer prevention services in a primary care setting.

Long-term stability in the richness and structure of helminth communities in eels, Anguilla anguilla, in Lough Derg, River Shannon, Ireland.

A data set on intestinal helminth parasites was collected in the course of an 18 year investigation into the biology of eels in Meelick Bay, Lough Derg, River Shannon. This was used to test two hypotheses relating to the composition and structure of intestinal helminth communities, namely that eels in large rivers do not harbour richer and more diverse communities than those in small rivers but that community composition and structure are more stable over time than in small rivers. The helminth community was species poor, with only six species comprising the component community and a maximum infracommunity richness of three species. The community was overwhelmingly dominated by the acanthocephalan Acanthocephalus lucii, reflecting the importance of its intermediate host Asellus aquaticus in the eels' diet. The remaining helminth species contributed to species richness but made very little contribution to community diversity. Population levels of Acanthocephalus lucii fell and remained low between 1992 and 2000, probably reflecting increased movement of eels from other parts of the lough into Meelick Bay. Diversity values were low, but similar to those reported from other rivers in Britain and Europe. The results provided support for both hypotheses and indicated that in respect of richness, diversity and dominance, the helminth communities of eels in the River Shannon were typical of, and comparable to, those of other large rivers throughout Europe.

Lead attenuation of episodic growth hormone secretion in male rats.

The purpose of this study was to characterize the effects of chronic lead exposure on growth hormone and insulin-like growth factor-1 status in growing male rats. Pituitary growth hormone content, episodic growth hormone release, plasma insulin-like growth factor-1 levels, and growth hormone response to exogenous growth hormone-releasing factor were quantified in young rats given lead nitrate. Twenty male Sprague-Dawley weanling rats were given lead nitrate (1000 ppm lead) in drinking water for a period of 6 weeks. Lead treatment significantly reduced body weight gain. Pituitary growth hormone content was not altered by lead treatment. Mean plasma growth hormone levels were reduced 44.6% by lead treatment (46.41 +/- 6.2 ng/ml; p = .003) as compared to controls (83.82 +/- 10 ng/ml). Lead treatment reduced mean growth hormone peak amplitude by 37.5%, mean nadir concentration by 60%, and growth hormone peak area by 35%. These findings are consistent with decreased hypothalamic growth hormone-releasing factor secretion or reduced somatotrope responsiveness. Exogenous growth hormone-releasing factor increased plasma growth hormone in lead-treated and control rats. However, this response was blunted by the lead treatment (lead treated: 485.6 +/- 57.8 vs. controls: 870.2 +/- 127 ng/ml; p = .03). Plasma insulin-like growth factor-1 concentration was not significantly affected by lead treatment. These results demonstrate that lead intoxication attenuates growth hormone release without abolishing the hypothalamic endocrine mechanisms driving growth hormone pulsatility. This suggests that lead acts at the level of the pituitary somatotroph rather than at the level of the hypothalamus.

Effect of a short course of rhDNase on cough and mucociliary clearance in patients with cystic fibrosis.

The aim of the study was to measure the effect of a short course of recombinant human deoxyribonuclease I (rhDNase) on ciliary and cough clearance in a group of cystic fibrosis patients, using a radioaerosol and gamma camera technique. Patients were initially randomized to receive either rhDNase (2.5 mg qd) or placebo. Following the measurement of baseline clearance, patients were given a 7-day course of either rhDNase or placebo. The patient then returned on the seventh day for follow-up clearance measurements. This was followed by a 2-week washout period before the whole process was repeated with the alternative inhalation solution. On each of the study days, mucociliary clearance was initially measured for a period of 60 min (IC). This was followed by cough clearance (CC) measurements for 30 min, during which patients were requested to cough a total of 120 times. Post-cough clearance (PCC) was then measured for a further 60 min. Thirteen patients completed the study. Patients' age ranged between 18-38 years, and they had baseline values of FEV(1) of 27-103% of predicted values. Following completion of the course of rhDNase, there was a mean percent increase from baseline of 7.5% for FEV(1) and 5.4% for FVC% (P = 0. 03). There was a small, nonsignificant increase in IC (6.2 +/- 3.6%) on the rhDNase arm compared with the placebo arm (-2.3 +/- 2.9%), P = 0.1. No changes were seen in either CC (1.0 +/- 3.2% [rhDNase] vs. 1.9 +/- 2.4% [placebo], P = 0.9) or PCC (-0.7 +/- 1.5% [rhDNase] vs. 0.9 +/- 1.7% [placebo], P = 0.3). Patients who achieved a 10% or greater improvement in FEV(1) (n = 5) in response to rhDNase did not show any greater change in clearance than nonresponders. In conclusion, we were unable to demonstrate any improvements in either ciliary or cough clearance in response to a short course of rhDNase. The mechanism of action of this drug in vivo remains uncertain.

Preventive practicum training in healthcare organizations. The Meharry model.

BACKGROUND: Practicum training for preventive medicine residents often occurs in agencies whose community is geographically defined and whose governance is closely linked to public election. We were unsure about the financial ability of such departments to support training and are concerned that over-reliance on traditional health departments might not be best for either medically indigent populations or preventive medicine. We, therefore, sought to apply a public health model--based on a strategic partnership between nursing and preventive medicine--to a large health care organization. The result was formation of a mini-health department, suitable for fully accredited preventive medicine practicum training, within the Alvin C. York Veterans Affairs Medical Center, Murfreesboro, TN. This Center serves a defined population of 21,594 patients and about 1600 employees. The theoretical framework for the new department was based on demonstration of a close fit between the competencies expected of preventive medicine physicians by the American College of Preventive Medicine (ACPM) and activities required by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). Because of JCAHO requirements, many healthcare organizations already pay for preventive medicine services. CONCLUSIONS: By placing preventive medicine training faculty into existing budget slots at our institution, systemwide personnel costs for prevention decreased by about $36,000 per year, even as personnel funding for preventive medicine physicians increased from about $24,000 to $376,000 per year. Moreover, there was dramatic, sustained improvement in 17 indicators of preventive care quality as determined by an external peer review organization. In addition to providing a new venue for training, this model may also improve the quality and reach of preventive services, decreased fixed costs for service delivery, and yield new employment opportunities for preventive medicine physicians.

Long-PCR of the ANP gene and PCR-SSCP analysis of the proximal promoter region of the ANP gene in patients with aldosterone producing adenoma.

Previous studies have shown a significant association between allelic frequencies at the ANP gene locus and aldosterone responsiveness to angiotensin in aldosterone-producing adenoma (APA). We searched for any gross insertions or deletions in the ANP gene in APA and any associations between allelic frequencies at the Hpa II and Sca I RFLP sites within the ANP gene and angiotensin-responsive and unresponsive APA and normal subjects. We also searched for possible point mutations in the promoter region of the ANP gene (-595 to transcription start site) in peripheral blood and tumor DNA from 59 patients with APA and in peripheral blood DNA from 39 normal subjects by polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP) analysis. No large alterations in the ANP gene were observed, and no difference in allelic frequencies at the RFLP sites were seen between the two tumor subtypes, angiotensin-responsive and angiotensin-unresponsive APA, or between the APA group and normal subjects. SSCP analysis, however, did reveal mutations in the promoter region of the ANP gene (-375 to -595) in both peripheral blood and tumor DNA from 8 of 59 (14%) patients with APA, compared with only one of 39 normal controls (2.6%). This study suggests that alterations in the proximal promoter region of the ANP gene in APA may be important in the regulation of ANP transcription and may be involved in the underlying pathophysiology of aldosterone-producing adenoma in at least some patients.

Effect of exposure to low level lead on growth and growth hormone release in rats.

This study was undertaken to examine the effect of exposure to low level lead on growth and growth hormone (GH) release. Female pups exposed to lead beginning in utero were smaller than controls on postnatal day 7 (P = 0.06). There was no corresponding effect in males. No overall differences in body weights were detected in either sex with respect to treatment effect. No differences in food or water intake were observed at any time. Pituitaries from 49-day-old lead-treated pups responded to in vitro incubation with growth hormone releasing factor (GRF) with a smaller increase in GH release than those from control pups (P = 0.08). In the case of the dams, lead did not affect body weight, body length, food consumption or pituitary responsiveness; however, water consumption was significantly increased in the lactating dam (P < 0.05). Interestingly, blood lead content in 5-day-old pups (43.3 +/- 2.7 micrograms/dl) exposed to lead in utero was more than twice that of their 49-day-old litter-mates (18.9 +/- 0.7 micrograms/dl). At 49 days blood lead levels in female pups (19.94 +/- 0.8 micrograms/dl) were significantly higher than those of male pups (17.00 +/- 1.1 micrograms/dl). Maternal blood lead levels on the same day averaged 22.7 +/- 2.5 micrograms/dl. This study suggests that exposure to a low level of lead can reduce pituitary responsiveness to a hypothalamic stimulus. In addition, the data reinforce the importance of considering age and sex when evaluating the toxic effects of lead.

Functional evaluation of T helper, T suppressor, and B lymphocytes in lethally irradiated rhesus monkeys injected with autologous bone marrow.

Lethally irradiated rhesus monkeys were treated with autologous bone marrow that had either been (1) nontreated, i.e., normal; (2) depleted of T lymphocytes with a monoclonal antibody directed against rhesus T lymphocytes; (3) fractionated with the soybean agglutinin (SBA- fraction); or (4) fractionated with SBA and further depleted of T cells by E-rosetting. There was no difference in hematologic reconstitution among the animals, but all showed a marked lowering of the T helper/T suppressor ratio during the first 10 months posttransplant and reduced capability of their peripheral blood leukocytes (PBL) to produce Ig upon stimulation with pokeweed mitogen. This subnormal ability of PBL to produce Ig, as measured by plaque-forming cells in a reverse hemolytic plaque assay, was not explained entirely by the altered T-H/T-S ratio but was correlated with the functional status of the T-H, T-S, and B lymphocytes. Isolated populations of the different lymphocyte subsets from PBL of the experimental animals were cocultured with normal cells of the appropriate subset to obtain Ig synthesis when stimulated with PWM. Animals treated with normal bone marrow showed recovery of T-H cell function after 5 months, but their T-S cells showed excessive suppressor activity that persisted for 20 months posttransplant. In contrast, those animals receiving treated marrow (mAb plus complement, or SBA) showed a much-delayed (12 months or more) return to normal T-H cell function and an earlier return of T-S cells expressing a normal level of suppressor activity. Since the SBA- fraction of marrow contains very few or no T-H cells and T cell depletion of marrow with mAb also removes these cells, it is suggested that the kinetics of immune recovery of the different lymphocyte subsets of PBL is influenced by the presence or absence of T-H cells in the marrow inocula.

Effect of lead on TRH and GRF binding in rat anterior pituitary membranes.

The effect of lead on binding of the hypothalamic peptides thyroid releasing hormone (TRH) and growth hormone releasing factor (GRF) to rat anterior pituitary receptors was examined in this study. Concentrations of lead ranging from 0.01 to 1 microM did not alter [3H]TRH binding; concentrations above 1 microM increased TRH association with pituitary receptors. A previously uncharacterized ligand, [125I]GRF (human 1-44 amide), was used to examine the binding of GRF to anterior pituitary receptors. A high affinity site (GRFH = 18.1%, KH = 11.5 pM) was displaced by human growth hormone releasing factor (hGRF) (1-44)-NH2 or hGRF (1-29)-NH2 but not by rat growth hormone releasing factor (rGRF) (1-29)-NH2. Use of this ligand also revealed a class of low affinity binding sites (GRFL = 81.9%, KL = 0.39 microM) which has not been previously described. The low affinity site could be displaced by hGRF (1-44)-NH2, hGRF (1-29)-NH2 and rGRF (1-29)-NH2. A synthetic growth hormone releasing peptide (GHRP) also interacted with the low affinity GRF binding site. Lead dose-dependently displaced the binding of [125I]GRF to its pituitary receptors. The IC50 of lead for inhibiting [125I]GRF binding was 0.195 mM added lead or 52 pM free lead. These data suggest that one mechanism by which lead may affect pituitary function is through inhibition of receptor binding.

Blood histamine and solid malignant tumors.

A clinical study was performed to determine whether patients with a newly diagnosed solid malignant tumor manifest an alteration in whole-blood histamine levels. Our results indicate that such patients have blood histamine nearly three times greater than either normal, healthy individuals or noncancerous disease controls. Following surgical removal of the tumor, blood histamine levels remained high for 2 months and then dropped close to the normal range 3 months after surgery. Basophil counts did not change significantly in the presence of a malignant tumor. Patients receiving either chemotherapy or radiation therapy, and terminal cancer patients who were no longer receiving any therapy except for pain control had blood histamine within or below the normal range. By analogy with animals studies, we suggest that nascent histamine synthesis is increased in the presence of a developing tumor. The clinical usefullness of this observation remains to be determined.

Co-existence of congeneric species of acanthocephala: Acanthocephalus lucii and A. anguillae in eels Anguilla anguilla in Ireland.

A population of eels Anguilla anguilla from Lough Derg, R. Shannon, Ireland, harbouring infections of both Acanthocephalus lucii and A. anguillae was studied over three years. Both parasite species had the same intermediate host and eels appeared to be the only definitive host for A. anguillae. Throughout the whole period, A. lucii was the dominant parasite, was over-dispersed throughout the eel population and most frequently occurred as a single species infection. A. anguillae was far less common, its dispersion was close to random at most times and it almost invariably occurred as a mixed species infection. The proportions of the two species remained fairly constant over the period. Despite some indication of site selection in the intestine, the distribution of both species overlapped considerably and there was no evidence of competitive displacement of one species by the other or of resource partitioning in space. The life-histories of both species were similar: they infected eels, bred and were lost from fish at the same time of year and there was no indication of resource partitioning in time. Congeneric species of acanthocephalans can thus co-exist in apparently stable equilibrium in fish as predicted and without any evidence of interactions, but it is still considered that exploitation competition between the species may be occurring in eels.

The effect of calcium and cyclic AMP on amylase release in digitonin-permeabilized parotid gland cells.

Rat parotid cells were permeabilized with digitonin to examine their secretory dynamics. Cells were isolated by a modification of the method previously described by Hootman [1985). J. Biol. Chem. 260, 4186-4194) in which alpha-chymotrypsin was included. The final preparation consisted of approx. 40-60% single cells. The cells were 85-90% viable by trypan blue exclusion and secreted amylase when stimulated with isoproterenol. Digitonin (2 or 5 microM) was sufficient for permeabilization while 2 microM digitonin was somewhat more effective in maintaining cell integrity as indicated by lactate dehydrogenase release. Digitonin had minimal effects on intracellular granules in the whole cell and was, thus, relatively selective. The response of digitonin-permeabilized cells to calcium (without secretagogues) in the incubation medium was monitored by amylase release. For a wide range of applied free calcium concentrations (1 X 10(-7) M to 10(-4) M) a statistically significant increase in amylase secretion was observed. Control cells did not release amylase to a similar extent without secretagogue. Cyclic AMP (50 microM) significantly enhanced amylase secretion from digitonin-treated cells at all concentrations of free calcium tested. Neither calcium nor cyclic AMP alone was sufficient to stimulate maximal amylase release. Our results provide direct evidence for a model in which calcium and cyclic AMP work on separate pathways as interacting regulators of exocytosis.

Childhood lead toxicity and impaired release of thyrotropin-stimulating hormone.

Decreased stature of children is epidemiologically associated with increased blood lead independent of multiple socioeconomic and nutritional variables. Since endocrine dysfunction occurs in adult lead workers, we studied two girls, 2 years of age, before and after calcium disodium edetate chelation for blood leads (PbB) of 19-72 micrograms/dl. The height of both children had crossed from the 50th to below the 10th percentile during the course of chronic lead toxicity. Basal free T4, T4, T3, cortisol, somatomedin C, and sex steroids were normal. A decrease in the growth hormone response and elevation of basal prolactin and gonadotropins were noted in one. Both children demonstrated blunted thyrotropin-stimulating hormone (TSH) responses to thyrotropin-releasing hormone (TRH) in six of seven challenges. This prompted in vitro studies of cultured cells from rat pituitaries. After incubation of pituitary cells with 0.1-10 microM Pb2+ for 2 hr, followed by the addition of TRH, there was a dose-dependent inhibition of TSH release. Lead did not interfere with the assay of TSH. To investigate the interaction of lead and calcium, 45Ca2+ kinetic analyses were done on rat pituitary slices after 1 hr incubation with 1.0 microM lead. The impaired late efflux was consistent with a decrease in the size and exchangeability of the tightly bound pool of intracellular microsomal or mitochondrial calcium. The rat pituitary cell model provides a model for the decreased TSH release of lead poisoning, supports the biological plausibility of a neuroendocrine effect on growth, and suggests that interference with calcium-mediated intracellular responses is a basic mechanism of lead toxicity.

Isolation and characteristics of bovine pituitary secretory granules.

Secretory granules containing primarily growth hormone and prolactin were isolated from bovine anterior pituitaries. Marker enzyme analysis and electron microscopy indicated that the secretory granule fraction did not contain measureable amounts of other intracellular organelles. Such isolated granules were resistant to a variety of chemical and physical challenges including variations in osmolarity, ionic strength, EGTA, sonication, boiling, etc. The only treatments that were found to routinely result in granules lysis were alkaline pH and 0.5% SDS. Nonspecific leakage of both growth hormone and prolactin was less than 9% of total hormone pool even after a 60-min incubation. The release of prolactin but not growth hormone could be increased by lowering the free calcium concentration. Conversely, 10(-5) M ionophore A23187 caused a decrease in nonspecific hormone leakage. This raises the possibility that a nonexocytosis secretory pathway might be involved in pituitary hormone release. The initial secretory granule fraction was further purified using discontinuous sucrose gradient ultracentrifugation to yield a subfraction highly enriched in prolactin granules. These granules had the same stability characteristics as the original secretory granule fraction. The use of such granules should prove useful in our efforts to understand how calcium regulates cellular secretion.

Calcium movements and intracellular calcium distribution in neoplastic GH3 cells.

Experiments were carried out to investigate the nature of the calcium homeostatic mechanisms in neoplastic GH3 rat pituitary cells. GH3 cells grown and maintained in Ham's F10 culture medium contained 35 nmoles calcium/mg cell protein. When stimulated by thyrotropin releasing hormone (TRH) or elevated K+ concentrations, only the latter caused cell calcium levels to rise although both resulted in hormone release. When exposed to EGTA, the GH3 cells lost calcium. When the temperature was lowered to 4 degrees C, the cells gained calcium and when rewarmed were able to extrude the previously accumulated calcium. The increased cell calcium following cold exposure could be blocked by prior treatment with rotenone. If rotenone was added subsequent to the cold exposure, it did not block the extrusion seen upon rewarming. In the absence of glucose in the medium, the GH3 cells took up more calcium upon exposure to 4 degrees C, and upon rewarming the cells could not return to their previous low levels. There are thus significant differences in calcium homeostasis between the neoplastic GH3 cells and their normal pituitary counterparts. When intracellular calcium was localized with the potassium pyroantimonate technique, there was calcium found in/on mitochondria, membrane bound vesicles and plasma membrane. Nuclear staining was sparse, and nucleolar staining was virtually absent. Upon stimulation with TRH, there was a decrease in mitochondrial calcium along with increases in both plasma membrane and nucleolar calcium levels. Since total calcium is unchanged, this indicates a significant calcium redistribution in response to TRH. The increased nucleolar calcium may reflect a calcium dependent increase in mRNA synthesis as has been reported. Since TRH presumably acts at a surface receptor, the increased plasma membrane calcium might be functionally related to receptor activation.

Effect of normal and cystic fibrotic serum on ion transport and mucus glycoprotein secretion from the isolated rabbit trachea.

It has been argued that individuals with cystic fibrosis (CF) might be expected to lead reasonably normal lives if the secondary changes associated with the disease could be eliminated or overcome. The purpose of this study was to characterize the electrical and transport properties of the isolated rabbit trachea in the presence and absence of control or CF serum. In addition, we sought to determine whether the presence of CF serum resulted in an alteration in either the amount or type of mucus glycoprotein secreted by the trachea. It was found that both control and CF sera inhibited the short-circuit current of the rabbit trachea due primarily to an inhibition of active sodium transport. The effect was irreversible and could be abolished by heating the serum prior to the experiment and was only observed when the serum was on the luminal surface. There was no differential effect between control or CF serum. Investigation also indicated that exposure of the isolated trachea to CF sera had no effect on the amount of mucus glycoproteins as indicated by the degree of sulfation in secretion samples eluted from DEAE cellulose following exposure to CF serum. It is possible that alterations in the type of mucus secreted subsequent to exposure to CF serum might relate to the turbidity of the mucus seen in such patients.