The effects of warming by active and passive means on the subsequent responses to cold water immersion

Two experiments were undertaken to investigate the effects of warming the body upon the responses during a subsequent cold water immersion (CWI). In both experiments the subjects, wearing swimming costumes, undertook two 45-min CWIs in water at 15° C. In experiment 1, 12 subjects exercised on a cycle ergometer until their rectal temperatures (T _re) rose by an average of 0.73°C. They were then immediately immersed in the cold water. Before their other CWI they rested seated on a cycle ergometer (control condition). In experiment 2, 16 different subjects were immersed in a hot bath (40° C) until their T _re rose by an average of 0.9° C; they were then immediately immersed in the cold water. Before their other CWI they were immersed in thermoneutral water (35° C; control condition). Heart rate in both experiments and respiratory frequency in experiment 1 were significantly (P < 0.05) higher during the first 30 s of CWI following active warming. In experiment 1, the rate of fall of T _re during the final 15 min of CWI was significantly (P < 0.01) faster when CWI followed active warming (2.46° C · h^–1) compared with the control condition (1.68°C · h^–1). However, this rate was observed when absolute T _re was still above that seen in the control CWIs. It is possible, therefore, that if longer CWIs had been undertaken, the two temperature curves may have converged and thereafter fallen at similar rates; this was the case with the aural temperature (T _au) seen in experiment 1 and the T _au and T _re in experiment 2. It is concluded that pre-warming is neither beneficial nor detrimental to survival prospects during a subsequent CWI.     

Regulation, replication, and integration functions of the Vibrio cholerae CTXφ are encoded by region RS2

CTXφ is a filamentous phage that encodes cholera toxin, one of the principal virulence factors of Vibrio cholerae . CTXφ is unusual among filamentous phages because it can either replicate as a plasmid or integrate into the V. cholerae chromosome at a specific site. The CTXφ genome has two regions, the 'core' and RS2. Integrated CTXφ is frequently flanked by an element known as RS1 which is related to RS2. The nucleotide sequences of RS2 and RS1 were determined. These related elements contain three nearly identical open reading frames (ORFs), which in RS2 were designated rstR , rstA2 and rstB2 . RS1 contains an additional ORF designated rstC . Functional analyses indicate that rstA2 is required for CTXφ replication and rstB2 is required for CTXφ integration. The amino terminus of RstR is similar to the amino termini of other phage-encoded repressors, and RstR represses the expression of rstA2 . Although genes with related functions are clustered in the genome of CTXφ in a way similar to those for other filamentous phages, the CTXφ RS2-encoded gene products mediating replication, integration and repression appear to be novel.     

Long-Term Drug Treatment of Obesity in a Private Practice Setting

ATKINSON, RICHARD L, ROY C BLANK, DONALD SCHUMACHER, NIKHIL V DHURANDHAR, DOUGLAS L RITCH. Long-term drug treatment of obesity in a private practice setting. This study evaluated the long-term efficacy and safety of the combination of phentermine and fenfluramine for the treatment of obesity in a private practice setting. A total of 1388 consecutive, qualified patients presenting to a private general internal medicine practice in Charlotte, NC, were enrolled with eligibility criteria including: age 18 years to 60 years, 20% over “desirable” bodyweight or body mass index <27, no serious medical or psychiatric disease, and no contraindications to drug therapy. Patients were instructed in diet, exercise, and behavior modification techniques and received phentermine (15 mg/day to 30 mg/day) and fenfluramine (20 mg/day to 60 mg/day) continuously for over 3 years. Average duration of treatment was 15. 9 months, and average weight loss at the last visit was 11. 6 kg, or 11. 7% of initial bodyweight. For patients completing 1 year of drug treatment, mean weight loss was 16. 5 kg, or 16% of initial weight. Weight loss persisted for 2 years, but partial regain was seen at 3 years. The dropout rates were 18% at 6 months, 39% at 1 year, 68% at 2 years, and 78% at 3 years. At 1 year, blood pressure of hypertensive patients fell from 151/95 mm Hg to 127/78 mm Hg, and serum cholesterol and triglycerides of hyperlipidemic patients fell by 0. 750 mmol/L (29 mg/dL) and 0. 937 mmol/L (83 mg/dL), respectively. Adverse events were modest. We conclude that, in a private practice setting, long-term treatment of obesity with the combination of phentermine, fenfluramine, and a weight maintenance program is generally safe and effective. More research is needed to determine efficacy and safety for longer than 3 years.     

Surgical Treatment of Constipation

A 30-year retrospective review of 544,354 Seattle area hospital admissions yielded 25 patients who underwent surgical therapy for the relief of intractable idiopathic constipation. All patients were refractory to conventional medical treatment consisting of the daily use of laxatives, cathartics, emollients or enemas. Long-term follow-up was available for 13 of the 25 patients. All 13 patients had clinical improvement as a result of the operation. This confirms results reported by other authors. Subtotal colectomy and left hemicolectomy are the procedures generally favored.     

Selected aspects of collared peccary (Dicotyles tajacu) reproductive biology in a captive texas herd

Collared peccaries (Dicotyles tajacu) from 32 litters were born in captivity during the period from September, 1981 through July, 1983. Incidence of singleton, twin, and triplet litters was 28%, 66%, and 6%, respectively. Mean (± SE) weight of young from singleton, twin, and triplet litters was 751 (± 35) gm, 698 (± 17) gm, and 612 (± 74) gm, respectively. Sex ratio among all litters was 56:44 (M:F). Neonatal mortality amounted to 9% of the young born. Mean duration of estrus was 2.60 days and mean length of gestation was 145.6 days. Evidence indicated that multiple copulations increased ovulation rate and the chance for conception.     

Cytochemical and electrophoretic studies of haemoglobin synthesis in the fat body of a midge, Chironomus thummi

The fat body of developing mid- and late fourth instar larvae of a midge, Chironomus thummi, has been investigated by means of the benzidine reaction for the localization of haemoglobin within cells. In the subepidermal fat body the reaction deposits of the haemoglobin pseudo-peroxidase activity appear predominantly in the intracisternal cavities of ER and the Golgi, and later, in the pharate pupal stage, in small dense granules (0.5–1 μm in. diameter).All the major protein bands of fat body extracts, which are resolved in electrophoresis, give the benzidine reaction and show incorporation of ¹⁴C-amino levulinic acids, in this case a specific marker for haemoglobin synthesis. In addition, labelled proteins show identical electrophoretic mobility as the haemoglobins of the haemolymph, suggesting that haemoglobins are synthesized in the fat body. Two types of fat body cells seem to differ with respect to their rôle in haemoglobin metabolism.