Chloroplast sharing in the Tasmanian eucalypts.

The biogeographic pattern of chloroplast DNA (cpDNA) haplotypes in Eucalyptus on the island of Tasmania is consistent with reticulate evolution, involving at least 12 Tasmanian species from the subgenus Symphyomyrtus. Intraspecific cpDNA polymorphism in 14 of 17 species is coupled with extensive sharing of identical haplotypes across populations of different species in the same geographic area. Haplotype diversity is lowest in central regions of Tasmania formerly occupied by alpine vegetation during glacial intervals and in northern regions that were periodically linked to continental Australia by land bridges. The observed distribution of several cpDNA haplotypes unique to Tasmania coincides with modeled locations of glacial refugia in coastal areas of Tasmania and shows the power of cpDNA in unraveling the complex history of past distributions of Eucalyptus. The results suggest that the model of evolution of the eucalypts should be reassessed to allow for the anastomosing effects of interspecific hybridization and introgression.

Patient-administered tampon-collected genital cells in the assessment of Chlamydia trachomatis infection using polymerase chain reaction.

BACKGROUND: Diagnosis of genital Chlamydia trachomatis infection in women traditionally requires a speculum examination to collect endocervical cells, followed by cell culture. This method is time consuming, requires stringent transport conditions, and is technically demanding. GOALS: To compare tampons as a patient-administered collection method followed by detection with polymerase chain reaction (PCR) with the traditional endocervical swab culture followed by cell culture detection. STUDY DESIGN: At the emergency department of a hospital for obstetrics and gynecology, 1,000 consecutive women with symptoms suggestive of infection with C. trachomatis were tested for C. trachomatis infection by PCR on both tampon (PCR-T) and swab (PCR-S) specimen and by culture of the swab specimen. RESULTS: Seventeen PCR-T and 16 PCR-S specimens were positive; 16 endocervical specimens were positive by culture, and 14 of the endocervical samples were positive by the three methods. Sixty-one PCR-S samples were inadequate as shown by the lack of amplification of the beta-globin gene segment, indicating poor collection of specimens by endocervical swab for chlamydial testing. CONCLUSIONS: Tampon specimens collected for PCR detection provided an easy and sensitive method of detection of C. trachomatis and overcame the obstacle of endocervical sampling and subsequent stringent transport requirements of culture.

Left upper lobe mass and diffuse reticular-nodular infiltrate.

We encountered a clinical problem in a young man who presented with a left upper lobe mass and a diffuse reticular-nodular infiltrate. We thought we had appropriately applied Murphy's Law (the famed bank robber who "went where the money is"), and Ockham's Razor (the philosopher William of Ockham [1285 to 1349]-"Entities are not to be multiplied beyond necessity") as we rapidly diagnosed the lung mass with computed tomography, scintigraphy, and fine-needle aspiration. However, when his invaluable previous chest radiographs arrived, bronchoscopy with transbronchial biopsy, bronchoalveolar lavage, brushings, and postbronchoscopy sputum revealed the more ominous diagnosis in this patient. This case illustrates the complementary nature of current imaging and bronchoscopy techniques; but, even more importantly, it demonstrates the value of the history coupled with the previous radiograph. Even an unusual case can provide lessons in cost containment.

Bronchogenic carcinoma in patients seropositive for human immunodeficiency virus.

As the HIV epidemic continues and the patients are closely followed throughout the course of the illness from HIV seropositivity to depressed total CD4 counts, the natural history of lung cancer in this population is evolving. HIV-infected patients with lung cancer are in general younger men with significant smoking histories. Adenocarcinoma is the predominant cell type. There has been no correlation between stage of lung cancer and CD4 counts. The lung cancer stage at presentation has also not affected prognosis (no survivors beyond 1 year from diagnosis). While HIV seropositivity has not yet been identified as a risk factor for bronchogenic carcinoma, the current literature suggests that lung neoplasms behave in an aggressive manner in HIV-positive patients. We present two cases to illustrate the value of transbronchial biopsy which should be performed in all patients with masses, nodules, or focal lesions that persist despite appropriate therapy for opportunistic organisms in HIV-positive patients.

Improvement in glucose tolerance of diabetic dogs after implantation of neonatal pancreatic fragments.

Minced neonatal pancreatic tissue from 3-6 canine littermates was placed in the peritoneal cavity of five alloxan diabetic dogs without separation of endocrine and exocrine tissue. Fasting blood glucose levels declined from a preimplant level of 211 +/- 57 mg/dl to 111 +/- 6 mg/dl. The maximum blood glucose following a glucose challenge declined from 387 +/- 26 mg/dl to 175 +/- 37 mg/dl. These levels were slightly higher than the 92 +/- 6 mg/dl fasting and 140 +/- 34 mg/dl maximum obtained in control dogs. Insulin levels before implant ranged from 6 to 11 microU/ml and showed no response to a glucose challenge. Insulin responses to a glucose challenge after implant were variable. Three of the dogs showed some hyperinsulinemia without hypoglycemia. Another dog showed a delayed insulin response of normal magnitude. Improvement in glucose tolerance lasted for 2-6 weeks. These results indicate that neonatal tissue can survive and function within the peritoneal cavity. It was not necessary to obtain isolated islets to achieve hormone secretion. However, additional purification may be needed to decrease the side effects of acinar enzymes.

Case study of a diabetic dog with chronic membranous glomerulopathy treated with continuous intraperitoneal insulin infusion.

The purpose of this study was to determine the use of continuous intraperitoneal insulin infusion over an extended period (in maintaining metabolic control) and to evaluate the benefits of this treatment in reversing the kidney pathology of a chronic diabetic dog with membranous glomerulopathy. Hyperglycemia was eliminated, but reevaluations of the insulin infusion pattern were necessary. An initial kidney biopsy revealed fusion of the foot processes, thickening of the basement membrane, and subendothelial deposition. After 5 months of infusion, there was less fusion of the foot processes and a decrease in the subendothelial deposition. Urinary protein loss decreased from 17.3 g/day to 625 mg/day after 2 months of infusion. The dog gained weight, muscle wasting was reversed, and his stamina returned while on continuous insulin infusion. The reduction of a life-threatening urinary protein loss to a tolerable level and the improvement in the microscopic kidney lesions observed indicate that this treatment with insulin infusion may be beneficial in the management of long-term diabetic dogs, affected with advanced kidney lesions secondary to diabetes.

Formation of ketone bodies from [14C]palmitate and [14C]glycerol by tissues from ketotic sheep.

Labelled ketone bodies were produced readily from [U-(14)C]palmitate, [2-(14)C]palmitate and [1-(14)C]glycerol by sheep rumen-epithelial and liver tissues in vitro. On a tissue-nitrogen basis, both tissues had similar capacities for ketogenesis. Palmitate was a ketogenic substrate in both rumen-epithelial tissue and liver, and more of its (14)C appeared in ketone bodies than in the (14)CO(2) liberated. Glycerol was actively metabolized to ketone bodies, but more readily underwent complete oxidation to carbon dioxide; this complete oxidation was most pronounced in rumen-epithelial tissue from ketotic ewes. These experiments with labelled compounds confirm earlier observations that rumen-epithelial tissue, like liver, actively forms ketone bodies from long-chain fatty acids and show further that normal rumen-epithelial tissue can convert palmitate into ketone bodies as readily as into carbon dioxide. Free glycerol, which is metabolized only by liver tissue in non-ruminants, is also metabolized by rumen epithelium. The rumen epithelium thus has unique metabolic capacity among extrahepatic tissues.