Novel sequence variants in the TMC1 gene in Pakistani families with autosomal recessive hearing impairment

Though many hearing impairment genes have been identified, only a few of these genes have been screened in population studies. For this study, 168 Pakistani families with autosomal recessive hearing impairment not due to mutations in the GJB2 (Cx26) gene underwent a genome scan. Two-point and multipoint parametric linkage analyses were carried out. Twelve families had two-point or multipoint LOD scores of 1.4 or greater within the transmembrane cochlear expressed gene 1 (TMC1) region and were subjected to further screening with direct DNA sequencing. Five novel putatively functional non-synonymous sequence variants, c.830A>G (p.Y277C), c.1114G>A (p.V372M), c.1334G>A (p.R445H), c.2004T>G (p.S668R), and c.2035G>A (p.E679K), were found to segregate within seven families, but were not observed in 234 Pakistani control chromosomes. The variants c.830A>G (p.Y277C), c.1114G>A (p.V372M), and c.1334G>A (p.R445H) occurred at highly conserved regions and were predicted to lie within hydrophobic transmembrane domains, while non-synonymous variants c.2004T>G (p.S668R) and c.2035G>A (p.E679K) occurred in extracellular regions that were not highly conserved. There is evidence that the c.2004T>G (p.S668R) variant may have occurred at a phosphorylation site. One family has the known splice site mutation c.536 -8T>A. The prevalence of non-syndromic hearing impairment due to TMC1 in this Pakistani population is 4.4% (95%CI: 1.9, 8.6%). The TMC1 protein might have an important function in K(+) channels of inner hair cells, which would be consistent with the hypothetical structure of protein domains in which sequence variants were identified.     

Isolation of an entomopoxvirus and characterization of its DNA.

An entomopoxvirus from Choristoneura biennis was propagated in the eastern spruce budworm, Choristoneura fumiferana. The virus, released from its inclusion bodies by alkaline treatment, sedimented as a homogeneous band by rate zonal centrifugation through sucrose gradients. Electron microscopic examination showed that the particles possessed the mulberrylike structure that is typical of intact entomopox virions. The virus also produced a single band by isopycnic centrifugation in CsCl at a density of 1.31 g/ml. The genome, extracted with sodium lauryl sarcosinate and Pronase, sedimented as a single band through sucrose gradients, and its MW was calculated to be 132?142 × 10⁶ when compared to marker DNA from coliphage T2. Its sedimentation coefficient was 59S. The G + C content of the viral genome was investigated by thermal denaturation and buoyant density analysis in CsCl. The DNA melted at 61.6° and had a density of 1.6849 g/ml. These values are equivalent to a G + C content of 26.6% and 25.4%, respectively, which are considerably lower than those reported for the genomes of vertebrate poxviruses (G + C, 32.5–39%). The difference in G + C content between vertebrate and invertebrate poxviruses was confirmed by characterizing the genome of a second entomopoxvirus with respect to its t_m and buoyant density. The double-stranded nature of the DNA from invertebrate poxviruses was established from melting profiles and reaction with formaldehyde.     

An Overview of the Treatment Options Used for the Management of COVID-19 in Pakistan: Retrospective Observational Study

BackgroundSince the first reports of COVID-19 infection, the foremost requirement has been to identify a treatment regimen that not only fights the causative agent but also controls the associated complications of the infection. Due to the time-consuming process of drug discovery, physicians have used readily available drugs and therapies for treatment of infections to minimize the death toll.ObjectiveThe aim of this study is to provide a snapshot analysis of the major drugs used in a cohort of 1562 Pakistani patients during the period from May to July 2020, when the first wave of COVID-19 peaked in Pakistan.MethodsA retrospective observational study was performed to provide an overview of the major drugs used in a cohort of 1562 patients with COVID-19 admitted to the four major tertiary-care hospitals in the Rawalpindi-Islamabad region of Pakistan during the peak of the first wave of COVID-19 in the country (May-July 2020).ResultsAntibiotics were the most common choice out of all the therapies employed, and they were used as first line of treatment for COVID-19. Azithromycin was the most prescribed drug for treatment. No monthly trend was observed in the choice of antibiotics, and these drugs appeared to be a random but favored choice throughout the months of the study. It was also noted that even antibiotics used for multidrug resistant infections were prescribed irrespective of the severity or progression of the infection. The results of the analysis are alarming, as this approach may lead to antibiotic resistance and complications in immunocompromised patients with COVID-19. A total of 1562 patients (1064 male, 68.1%, and 498 female, 31.9%) with a mean age of 47.35 years (SD 17.03) were included in the study. The highest frequency of patient hospitalizations occurred in June (846/1562, 54.2%).ConclusionsGuidelines for a targeted treatment regime are needed to control related complications and to limit the misuse of antibiotics in the management of COVID-19.     

Morbidity and Mortality Associated with Typhoid Fever Among Hospitalized Patients in Hyderabad District,Pakistan, 2017-2018: Retrospective Record Review

BackgroundHyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.ObjectiveTo address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.MethodsWe reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.ResultsA total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).ConclusionsAs this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures.     

Prevalence of Vision Loss and Associations With Age-Related Eye Diseases Among Nursing Home Residents Aged ≥65 Years

ObjectivesTo examine data from Delaware nursing homes to determine prevalence of age-related eye diseases (AREDs), vision impairment, and blindness and to compare the findings with the results of 11 US investigations of vision and eye health in nursing homes.DesignThis is a cross-sectional, retrospective study of nursing home patients.Setting and ParticipantsTwenty nursing homes in Delaware participated in the study, yielding comprehensive eye examination records for 2019 study participants.MethodsSummary statistics and regression analyses.ResultsThe overall prevalence of vision impairment or blindness was 63.8% and was above 60% for each age, sex, and race category. Prevalence of vision impairment or blindness was 68.4% among patients with cataracts, 69.4% among patients with macular degeneration, 70.5% among patients with glaucoma, and 68.4% among patients with diabetic retinopathy. Prevalence of blindness was 14.1%. Among patients with AREDs, prevalence of blindness ranged from 15.0% for patients with cataracts to 22.6% for patients with diabetic retinopathy. When compared with other investigations, we found wide variation in vision and eye factors reported and wide variation in the prevalence of those factors. Only 4 studies diagnosed both AREDs and visual function. Seven studies reported AREDs, and 7 reported vision impairment and/or blindness. Vision impairment or blindness ranged from 29% to 67%; cataract ranged from 32% to 83%; macular degeneration ranged from 4.6% to 70.7%. Glaucoma ranged from 5.3% to 41.4%; diabetic retinopathy ranged from 1.7% to 3.1%.Conclusions and ImplicationsComprehensive eye examinations showed that vision impairment and blindness affected 63.8% of nursing home residents. Compared with other studies, there was a wide range of vision factors reported and wide variation in the prevalence of vision impairment or blindness and AREDs. This investigation suggests the importance of eye care in nursing homes and the importance of reporting standard vision and eye health factors to inform policy and practice.     

Sperm binding to hyaluronan is an excellent predictor of Nili-Ravi buffalo bull fertility

This study reports the first evaluation of sperm hyaluronan binding assay (HBA) for predicting the fertility of Nili-Ravi buffalo bulls in relation to standard parameters of sperm quality. Cryopreserved semen doses of low (n = 6), medium (n = 3) and high fertility (n = 8) bulls based on their respective return rates were used. Significantly, more spermatozoa bound to hyaluronan from the most fertile bulls (57.15% ± 1.44) compared with medium (42.46% ± 1.08) and low fertility bulls (29.70% ± 0.78). A strongly positive correlation (r = .824, p < .01) was found between HBA and fertility that predicts a 67.9% variability (r² = .679, p < .01) in fertility. HBA was also strongly positively correlated with sperm viability (r = .679, p < .01) followed by their live/dead ratio (r = .637, p < .01), uncapacitated spermatozoa (r = .631, p < .01), normal apical ridge (r = .459, p < .01), motility (r = .434, p < .01), mature spermatozoa with low residual histones (r = .364, p < .01), high plasma membrane integrity (r = .316, p < .01) and nonfragmented DNA levels (r = .236, p < .05). It was negatively correlated with spermatozoa having reacted acrosome (r = −.654, p < .01). A fertility model built using a combination of sperm HBA and either sperm livability or viability predicts, respectively, 86.1% (r² = .861, p < .01) and 85.9% (r² = .859, p < .01) variability in buffalo bull fertility. In conclusion, sperm HBA may prove to be a single robust predictor of Nili-Ravi buffalo bull fertility.     

Endogenous animal models of intracranial aneurysm development: a review

Neurosurgical Review - The pathogenesis and natural history of intracranial aneurysm (IA) remains poorly understood. To this end, animal models with induced cerebral vessel lesions mimicking human...     

Adaptation of Insulin Clearance to Metabolic Demand Is a Key Determinant of Glucose Tolerance

With the development of insulin resistance (IR), there is a compensatory increase in the plasma insulin response to offset the defect in insulin action to maintain normal glucose tolerance. The insulin response is the result of two factors: insulin secretion and metabolic clearance rate of insulin (MCR_I). Subjects (104 with normal glucose tolerance [NGT], 57 with impaired glucose tolerance [IGT], and 207 with type 2 diabetes mellitus [T2DM]), divided in nonobese and obese groups, received a euglycemic insulin-clamp (40 mU/m² ⋅ min) and an oral glucose tolerance test (OGTT) (75 g) on separate days. MCR_I was calculated during the insulin-clamp performed with [3-³H]glucose and the OGTT and related to IR: peripheral (glucose uptake during the insulin clamp), hepatic (basal endogenous glucose production × fasting plasma insulin [FPI]), and adipocyte (fasting free fatty acid × FPI). MCR_I during the insulin clamp was reduced in obese versus nonobese NGT (0.60 ± 0.03 vs. 0.73 ± 0.02 L/min ⋅ m², P < 0.001), in nonobese IGT (0.62 ± 0.02, P < 0.004), and in nonobese T2DM (0.68 ± 0.02, P < 0.03). The MCR_I during the insulin clamp was strongly and inversely correlated with IR (r = −0.52, P < 0.0001). During the OGTT, the MCR_I was suppressed within 15–30 min in NGT and IGT subjects and remained suppressed. In contrast, suppression was minimal in T2DM. In conclusion, the development of IR in obese subjects is associated with a decline in MCR_I that represents a compensatory response to maintain normal glucose tolerance but is impaired in individuals with T2DM.