The variable influence of lifestyle and income on medical students' career specialty choices: data from two U.S. medical schools, 1998-2004.

PURPOSE: Recent reports on medical students' career choices suggest that lifestyle increasingly influences career decisions. The authors addressed the changing influence of lifestyle and income on career choice, how these influences differ by specialty, and the specific careers students identify as lifestyle friendly. METHOD: From 1998 to 2004, 1,334 (73%) fourth-year medical students from Brody School of Medicine at East Carolina University (no. = 485 graduates) and New York Medical College (no. = 1,348 graduates) completed a questionnaire that addressed career specialty preferences, as well as income and lifestyle concerns. Students were asked to rate career choice influences on a four-point scale (1 = no influence, 4 = major influence). Factor analysis of these influences identified seven factors including one each for lifestyle and income. RESULTS: A total of 1,327 students indicated a career preference. Lifestyle (p = .018) and income (p = .011) were found to increasingly influence medical students' career choices during the study period. Overall, the authors found significant differences between specialties in the relative contribution of these factors. Students' perceptions of specialties existed on a continuum of lifestyle friendly (e.g., radiology) to lifestyle unfriendly (e.g., obstetrics-gynecology). Contrary to previous reports, the students' responses indicate they perceived the primary care specialties as lifestyle intermediate compared to other specialties. CONCLUSIONS: Lifestyle and income have become more important to medical students in their career choice, and the relative influence of these factors varies considerably between specialties. This study suggests that previous efforts to dichotomize careers into those with controllable and uncontrollable lifestyles may mask important complexities.     

Changes in electromyographic activity,muscle fibre and force production characteristics during heavy resistance/power strength training in middle‐aged and older men and women

The effects of a 6‐month resistance training (2 day/week) designed to develop both strength and power on neural activation by electromyographic activity (EMG) of the agonist and antagonist knee extensors, muscle fibre proportion and areas of type I, IIa, and IIb of the vastus lateralis (VL) as well as maximal concentric one repetition maximum (1 RM) strength and maximal and explosive isometric strength of the knee extensors were examined. A total of 10 middle‐aged men (M40; 42 ± 2), 11 middle‐aged women (W40; 39 ± 3), 11 elderly men (M70; 72 ± 3) and 10 elderly women (W70; 67 ± 3) served as subjects. Maximal and explosive strength values remained unaltered during a 1‐month control period. After the 6‐month training maximal isometric and 1RM strength values increased in M40 by 28 ± 14 and 27 ± 7% (P < 0.001), in M70 by 27 ± 17 and 21 ± 9% (P < 0.001), in W40 by 27 ± 19 and 35 ± 14% (P < 0.001) and in W70 by 26 ± 14 and 31 ± 14% (P < 0.001), respectively. Explosive strength improved in M40 by 21 ± 41% (P < 0.05), in M70 by 21 ± 24% (P < 0.05), in W40 by 32 ± 45% (NS) and in W70 by 22 ± 28% (P < 0.05). The iEMGs of the VL and vastus medialis (VM) muscles increased during the training in M40 (P < 0.001 and 0.05), in M70 (P < 0.001 and 0.05), in W40 (P < 0.001 and 0.05) and in W70 (P < 0.001 and 0.05). The antagonist biceps femoris (BF) activity during the isometric knee extension remained unaltered in M40, in W40, and in M70 but decreased in W70 (from 42 ± 34 to 32 ± 26%; P < 0.05) during the first 2 months of training. Significant increases occurred during the training in the mean fibre areas of type I in W70 (P < 0.05) and of overall type II along with a specific increase in IIa in both W40 (P < 0.05) and in W70 (P < 0.05), while the changes in the male groups were not statistically significant. The individual percentage values for type II fibres at pretraining correlated with the individual values for 1 RM strength in both W70 (r=0.80; P < 0.05) and M70 (r=0.61; P < 0.05) and also at post‐training for maximal isometric torque in W70 (r=0.77, P < 0.05). The findings support the concept of the important role of neural adaptations in strength and power development in middle‐aged and older men and women. The muscle fibre distribution (percentage type II fibres) seems to be an important contributor on muscle strength in older people, especially older women. Women of both age groups appear to be hypertrophically responsive to the total body strength training protocol performed two times a week including heavier and lower (for fast movements) loads designed for both maximal strength and power development, while such a programme has limited effects on muscle hypertrophy in men.     

Oligonucleotide mapping of picornavirus RNAs by two-dimensional electrophoresis.

Considerable differences have been found in two-dimensional polyacrylamide gel electrophoresis fingerprints of complete ribonuclease T₁ digestion products of the RNAs of representative members of the entero-, cardio-, and foot-and-mouth disease virus subgroups of the picornavirus family. Individual members of the different subgroups, serotypes of a virus, and even subtypes within a serotype can be distinguished by the use of this technique. The method has also facilitated the identification of homopolymeric regions within the different picornavirus genomes, and the presence of a poly(C) tract in the cardio- and foot-and-mouth disease virus subgroups has been confirmed. A poly(A)-rich tract of approx 40–100 nucleotides has been detected in all the picornaviruses studied. Oligonucleotide fragments possibly specific to the enterovirus subgroup were also detected and partially characterised.     

Births of normal daughters after MicroSort sperm separation and intrauterine insemination, in-vitro fertilization, or intracytoplasmic sperm injection

The world's first deliveries of normal babies after use of flow cytometric separated human sperm cells (MicroSort) for preconception gender selection are reported. Offspring were of the desired female gender in 92.9% of the pregnancies. Most of these pregnancies and births were achieved after simple intrauterine insemination.      

Myosin VIIA gene: heterogeneity of the mutations responsible for Usher syndrome type IB

Usher syndrome is recognized as the most frequent cause of hereditary deaf-blindness. Usher syndrome type I (USH1), the most severe form of the disease, is characterized by profound congenital sensorineural deafness, constant vestibular dysfunction, and retinitis pigmentosa of prepubertal onset. This form is genetically heterogeneous and five loci (USH1A-E) have been mapped thusfar. However, only the gene responsible for USH1 B (which accounts for approximately 75% of USH1 cases) has been characterized. It encodes a long-tailed unconventional myosin, myosin VIIA, with a predicted 2215 amino acid sequence. Primers covering the complete myosin VIIA coding sequence as well as the 3' non coding sequence were designed, allowing direct sequence analysis of each of the 48 coding exons and flanking splice sites in seven patients affected by USH1. Four novel mutations were thereby identified. The possibility should now be considered of a sequence-based prenatal diagnosis in some of the families affected by this very severe form of Usher syndrome.      

A 3 year retrospective review of intrauterine insemination, using cryopreserved donor spermatozoa and cycle monitoring by urinary or serum luteinizing hormone measurements

Insemination with donor spermatozoa is an integral part of infertility treatment. For the last 3 years in our unit, intrauterine insemination with donor spermatozoa (IUID) has been used in preference to vaginal insemination. In this retrospective study, patients were offered an initial course of five single intrauterine inseminations with cryopreserved donor spermatozoa and treatment was then reviewed. A total of 389 patients received 1465 inseminations. In all, 1119 cycles were monitored using luteinizing hormone serum analyses and 346 cycles using the urine home test kits. The clinical pregnancy rate per insemination for the cycles monitored by the serum assay was 18.0% (202/1119) compared with the urine cycles (13.7%, 46/346) (P <05). The pregnancy loss rate was not significantly different (14.4%, 29/202 and 21.7%, 10/46) (serum and urine cycles respectively). The viable clinical pregnancy rate was significantly higher (P <03) for the serum cycles than for the cycles using the urinary monitoring (15.5%, 173/1119 and 10.4%, 36/346 respectively). The cycles monitored by serum assay had a significantly higher cumulative viable clinical pregnancy rate (P <0001) of 70.2% after nine inseminations compared with the urine monitored cycles of 54.8%. The majority of patients opted for the serum cycles, with a minority self-selecting the urine cycles mainly for travelling convenience. The explanation for the significant differences between the viable clinical pregnancy rates per insemination and the cumulative viable clinical pregnancy rates may be due to the sensitivity of the urine home test kit or the patients' interpretation of the result.      

Permeation of human ovarian tissue with cryoprotective agents in preparation for cryopreservation

The recent improvements in the treatment of cancer by chemo- and radiotherapy have led to a significant increase in the survival rates of patients with malignant disease, but at the expense of distressing side effects. One major problem, especially for younger patients, is that aggressive therapy destroys a significant proportion of the follicular population, which can result in either temporary or permanent infertility. Freeze-banking pieces of ovarian cortex prior to treatment is one strategy for preserving fecundity. When the patient is in remission, fertility could, theoretically, be restored by autografting the thawed tissue at the orthotopic site or by growing isolated follicles to maturity in vitro. Recent studies have found good follicular survival in frozen-thawed human ovarian tissue but to optimize the process an effective cryopreservation method needs to be developed. An essential part of such a technique is to permeate the tissue with a cryoprotectant to minimize ice formation and the extent of this equilibration is an important determinant of post-thaw cellular survival. In the current study, we have investigated the diffusion of four cryoprotective agents into human tissue at both 4 degrees C and 37 degrees C. We have also studied the effect of adding different concentrations of the non penetrating cryoprotective agent, sucrose, to the freezing media using the release of lactate dehydrogenase as a measure of its protective effect. At 4 degrees C propylene glycol and glycerol penetrated the tissue significantly slower than either ethylene glycol or dimethyl sulphoxide. At the higher temperature of 37 degrees C all four cryoprotectants penetrated at a faster rate, however concern about enhanced toxicity prevents the use of these conditions in practice. Thus, the results suggest that the best method of preparing tissue for freezing is exposure for 30 min to 1.5 M solutions of ethylene glycol or dimethyl sulphoxide at 4 degrees C; this achieved a mean tissue concentration that was almost 80% that of the bathing solution. We also report that the addition of low concentrations of sucrose to the freezing medium does not have a significant protective effect against freezing injury.